Lighting device, display device and television receiver

A backlight unit 12 according to the present invention includes LEDs 17 as light sources, an LED board 18 mounting the LEDs 17 thereon, a chassis 14 that stores the LED board 18 therein and includes an attachment hole 14e, a body portion 24 that sandwiches the LED board 18 between the body portion 24 and the chassis 14 and holds the LED board 18, and a board holding member 20 including an attachment portion 25 that is protruded from the body portion 24 toward the chassis 14 to be inserted into the attachment hole 14e, and the board holding member 20 is configured to be rotatable along a plate surface of the chassis 14 between a holding position at which the attachment portion 25 overlaps with an edge of the attachment hole 14e in a plan view and sandwiches the edge of the attachment hole 14e between the attachment portion 25 and the body portion 24 and a non-holding position at which the attachment portion 25 does not overlap with the edge of the attachment hole 14e in a plan view and attaching and detaching of the attachment portion 25 from the attachment hole 14e is allowed.

TECHNICAL FIELD

The present invention relates to a lighting device, a display device and a television receiver.

BACKGROUND ART

For example, a liquid crystal panel used for a liquid crystal display device such as a liquid crystal television set does not emit light by itself, and therefore, requires a separate backlight unit as a lighting device. The backlight unit is installed on a back side of the liquid crystal panel (side opposite to a display surface) and includes a chassis, a surface of which is opened on the side of the liquid crystal panel, a light source stored in the chassis, a reflection sheet that is arranged along an inner surface of the chassis and reflects light on the side of the opening of the chassis, and an optical member (diffuser sheet, etc.) that is arranged on the opening of the chassis and efficiently discharges light emitted from the light source to the liquid crystal panel side. Among the above-mentioned components of the backlight unit, in some cases, an LED for example, is adopted as the light source and in such case, an LED board that mounts the LED thereon is stored in the chassis.

An example of the backlight unit using the LED as the light source is described in Patent Document 1.

PRIOR ART DOCUMENT

Patent Document

Patent Document 1:

Problem to be Solved by the Invention

In fixedly attaching the LED board to the chassis, a screw has been generally used, and in attaching and detaching the LED board to/from the chassis, an operation of attaching and detaching the screw is needed. However, in the case of adopting a fixation method by use of the screw, the workability in the screw attaching and detaching operation itself is poor and a lot of screws are required to stably fix the LED board. As a result, disadvantageously, the number of components and the number of times of screw attaching and detaching operation increase, thereby degrading the workability. Especially, as the number of the LED boards increases with an increase in screen size of a liquid crystal display device, the number of screws used and the number of times of screw attaching and detaching works increase and accordingly, the above-mentioned problem becomes more prominent.

DISCLOSURE OF THE PRESENT INVENTION

The present invention is made based on the above-mentioned circumstances and intends to improve the workability in attaching the LED board to the chassis.

Means for Solving the Problem

A lighting device of the present invention includes a light source, a light source board, a chassis, and a board holding member. The light source is mounted on the light source board. The chassis stores the light source board therein and has an attachment hole. The board holding member includes a body portion and an attachment portion. The body portion holds the light source board such that the light source board is sandwiched between the body portion and the chassis. The attachment portion protrudes from the body portion toward the chassis and arranged inside the attachment hole. The board holding member is configured to be rotatable between a holding position and a non-holding position along a plate surface of the chassis. At the holding position, the attachment portion overlaps an edge of the attachment hole in a plan view and the edge of the attachment hole is sandwiched between the attachment portion and the body portion. At the non-holding position, the attachment portion does not overlap the edge of the attachment hole in a plan view and attaching and detaching of the attachment portion from the attachment hole is allowed.

With this configuration, to attach the light source board to the chassis, in the state where the light source board is stored in the chassis, the attachment portion of the board holding member is inserted into the attachment hole of the chassis, and the board holding member located at the non-holding position is rotated along the plate surface of the chassis. Then, the board holding member reaches the holding position, and the attachment portion overlaps with the edge of the attachment hole in a plan view and sandwiches the edge of the attachment hole between the attachment portion and the body portion, resulting that the board holding member is held to be attached to the chassis. In this state, the light source board is sandwiched between the body portion of the board holding member and the chassis, thereby being held to be attached to the chassis. Conversely, to detach the light source board from the chassis, the board holding member located at the holding position is rotated such that the attachment portion is located at the non-holding position at which the attachment portion does not overlap with the edge of the attachment hole in a plan view. At the non-holding position, since detaching of the attachment portion from the attachment hole is allowed, the board holding member can be detached from the chassis. As a result, since the holding state of the light source board by the board holding member is released, the light source board can be detached from the chassis.

Conventionally, since the light source board is screwed, the workability in the screw attaching and detaching operation itself is poor and therefore, workability tends to degrade. However, according to the present invention, by rotating the board holding member along the plate surface of the chassis between the non-holding position and the holding position, the board holding member can easily hold the light source board and the holding state can easily be released. Thus, the workability in attaching and detaching the light source board is excellent.

Since the board holding member according to the present invention holds the light source board between the board holding member and the chassis, for example, when the light source mounted on the light source board has a failure and replacement or repair of the light source board is required, it is needed to detach each of the board holding member and the light source board from the chassis. On the contrary, in the case of a lamp clip holding a cold-cathode tube, only the detaching operation of the cold-cathode tube is required. As compared to the case of the lamp clip, the frequency of the detaching operation of the board holding member tends to be higher. Furthermore, since the number of light source boards used tends to increase with an increase in the lighting device in size, the number of light source boards used and the number of times of the attaching and detaching operation of the board holding member tend to increase. In consideration of such circumstances, by improving the workability in attaching and detaching the board holding member holding the light source board, the workability in repairing the lighting device as well as the workability in the case of upsizing of the lighting device can be remarkably improved.

BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the present invention will be described with reference toFIGS. 1 to 21. In this embodiment, a liquid crystal display device10is used as an example. A part of each figure shows an X-axis, a Y-axis and a Z-axis, and a direction of each axis is represented in each figure. It is given that an upper side inFIGS. 4 and 5is a front side and a lower side in these figures is a back side.

A television receiver TV according to this embodiment includes, as shown inFIG. 1, the liquid crystal display device10, front and back cabinets Ca and Cb that store the liquid crystal display device10therebetween, a power source P, a tuner T and a stand S. The liquid crystal display device (display device)10is shaped like an oblong quadrangle as a whole (rectangular) and is stored in a vertically mounted state. The liquid crystal display device10includes, as shown inFIG. 2, a liquid crystal panel11as a display panel and a backlight unit (lighting device)12as an external light source, and these components are integrally held by a frame-like bezel13or the like. In this embodiment, it is assumed that a screen size is 42 inches and an aspect ratio is 16:9.

Next, the liquid crystal panel11and the backlight unit12that constitute the liquid crystal display device10will be successively described. The liquid crystal panel (display panel)11among them is rectangular in a plan view, and is formed by sticking a pair of glass boards to each other with a predetermined gap therebetween and filling a liquid crystal between the both glass boards. One glass board has a switching component (for example, TFT) connected to a source wiring and a gate wiring that are orthogonal to each other, a pixel electrode connected to the switching component and an alignment film and the like, and the other glass board has a color filter in which color sections of R(red), G (green), B (blue) are arranged in a predetermined pattern, a counter electrode and an alignment film and the like. Polarizing plates are provided outside of the both boards.

Subsequently, the backlight unit12will be described in detail. The backlight unit12includes, as shown inFIG. 2, a substantially box-like chassis14having openings14bon the side of a light emitting surface (the side of the liquid crystal panel11), an optical member group15(a diffuser (light diffusing member)15a, and a plurality of optical sheets15barranged between the diffuser15aand the liquid crystal panel11) arranged so as to cover the openings14bof the chassis14, and a frame16that is arranged along an outer edge of the chassis14and holds an outer edge of the optical member group15between the frame16and the chassis14. In the chassis14, as shown inFIGS. 3 to 5, LEDs17(Light Emitting Diode) as light sources, LED boards18that mount the LEDs17thereon and diffuser lenses19attached at positions corresponding to the LEDs17on the LED boards18are provided. The chassis14further includes board holding members20configured to hold the LED boards18between the board holding members20and the chassis14and a reflection sheet21that reflects light in the chassis14toward the optical member15. In the backlight unit12, the side of the optical member15, not the LEDs17, is set as a light emitting side. Hereinafter, each component of the backlight unit12will be described in detail.

The chassis14is made of metal, and as shown inFIGS. 3 to 5, consists of a rectangular bottom plate14aas in the case of the liquid crystal panel11, side plates14crising from outer ends of sides of the bottom plate14aand receiving plates14dextending outward from rising ends of the respective side plates14c, and is shaped like a shallow box (shallow dish) opened toward the front side as a whole. In the chassis14, its long-side direction corresponds to the X-axis direction (horizontal direction) and its short-side direction corresponds to the Y-axis direction (vertical direction). The frame16and the optical member15described below can be mounted on each receiving plate14dof the chassis14from the front side. The frame16is screwed into each receiving plate14d. The bottom plate14aof the chassis14includes attachment holes14eopened for attaching the board holding members20. The plurality of attachment holes14ein the bottom plate14acorresponding to attachment positions of the board holding members20is arranged. Details of the attachment hole14e, such as shape, will be described later.

As shown inFIG. 2, like the liquid crystal panel11and the chassis14, the optical member15is shaped like an oblong quadrangle (rectangular) in a plan view. As shown inFIGS. 4and5, the optical member15covers the openings14bof the chassis14by placing its outer edge on the receiving plates14d, and is interposed between the liquid crystal panel11and the LEDs17. The optical member15consists of the diffuser15aarranged on the back side (the side of the LEDs17, the side opposite to the light-emitting side) and the optical sheets15barranged on the front side (the side of the liquid crystal panel11, the light-emitting side). The diffuser15ais formed by dispersing multiple diffusing particles in a substantially transparent resin base member having a predetermined thickness and has a function of diffusing transmitted light. The optical sheet15bis shaped like a thinner sheet than the diffuser15aand two sheets are laminated (FIGS. 7 to 10). Specific examples of the optical sheets15binclude diffuser sheets, lens sheets, reflection type polarizing sheets, and it is possible to select and use any of these sheets as appropriate.

As shown inFIG. 2, the frame16is shaped like a frame along outer circumferences of the liquid crystal panel11and the optical member15. The outer edge of the optical member15is configured to be pinched between the frame16and each of the receiving plates14d(FIGS. 4 and 5). The frame16is configured to receive the outer edge of the liquid crystal panel11from the back side and pinch the outer edge of the liquid crystal panel11between the frame16and the bezel13arranged on the front side (FIGS. 4 and 5).

Next, the LEDs17and the LED boards18that mount the LEDs17thereon will be described in detail. As shown inFIGS. 7,8, and11, each of the LEDs17is formed by sealing an LED chip on a board portion fixedly attached to the LED board18with a resin material. The LED chip mounted on the board portion has one type of main light-emitting wavelength, and specifically, emits blue light only. Meanwhile, phosphors converting blue light emitted by the LED chip into white light are dispersedly mixed in the resin material sealing the LED chip. Thereby, the LED17can emit white light. This LED17is a so-called top type in which a surface on the side opposite to the mounting surface of the LED board18acts as a light-emitting surface17. An optical axis LA in the LED17substantially corresponds to the Z-axis direction (the direction orthogonal to the liquid crystal panel11and a main plate surface of the optical member15). Light emitted from the LEDs17spreads radially to some extent about the optical axis LA within a predetermined angular range in a three-dimensional way, and has a higher directivity than light from a cold cathode tube. That is, the light emission intensity of the LED17becomes remarkably high in a direction along the optical axis LA and rapidly lowers as inclination angle relative to the optical axis LA is larger.

As shown inFIG. 11, the LED board18has a rectangular (longitudinal) base material in a plan view, extends along the bottom plate14aand is stored in the chassis14so that its long-side direction matches the X-axis direction and its short-side direction matches the Y-axis direction (FIG. 3). The base member of the LED board18is made of metal such as aluminum material as in the case of the material for the chassis14, and has a surface on which a wiring pattern formed of a metal film such as a copper foil is formed via an insulating layer. Insulating materials such as ceramic can be used as the material for the base member of the LED board18. As shown inFIGS. 7,8, and11, the LEDs17having the above-mentioned configuration are mounted on a surface facing the front side (surface facing the optical member15side) among surfaces of the base member of the LED board18. The plurality of LEDs17is linearly arranged along the long-side direction of the LED boards18(X-axis direction) in parallel, and is serially connected according to the wiring pattern formed on the LED boards18. The alignment pitch of the LEDs17is almost constant, that is, the LEDs17are arranged at regular intervals. Wiring patterns WP extend in the X-axis direction of the LED board18, that is, in the long-side direction of the LED board18and the arrangement direction of the LEDs17. The pair of wiring patterns WP corresponding to an anode and a cathode of the LED chip of the LED17are arranged in parallel with each other with a predetermined interval therebetween. A connector18aconnected to each end of the wiring patterns WP is provided at each end of the LED board18in the long-side direction.

As shown inFIG. 3, the LED boards18having the above-mentioned configuration is arranged in the chassis14in each of the X-axis direction and the Y-axis direction so that the LED boards18are aligned in the long-side direction and the short-side direction in parallel. Specifically the LED boards18and the LEDs17mounted thereon are arranged in the chassis14in a matrix having the X-axis direction (the long-side direction of the chassis14and the LED board18) as a row direction and the Y-axis direction (the short-side direction of the chassis14and the LED board18) as the column direction. Specifically, the three LED boards18in the X-axis direction x the nine LED boards18in the Y-axis direction, that is, 27 LED boards18in total are arranged in the chassis14in parallel. In this embodiment, two types of LED boards18having different long-side dimensions and the number of mounted LEDs17are used. Specifically, a six-mounted type of the LED board18that mounts the six LEDs17thereon and has a relatively long long-side dimension and a five-mounted type of the LED board18that mounts the six LEDs17thereon and has a relatively short long-side dimension are used as the LED boards18, and one six-mounted type of the LED board18is arranged at each end of the chassis14in the X-axis direction and one five-mounted type of the LED board18is arranged at the center in the same direction. As described above, the LED boards18aligned in one row in the X-axis direction are electrically connected to each other by fitting the adjacent connector portions18awith each other, and the connector portions18alocated at both ends of the chassis14in the X-axis direction are each electrically connected to an external control circuit not shown. Thereby, the LEDs17arranged on the LED board18forming one row are serially connected to one another, so that lighting-on and off of the multiple LEDs17contained in the one row can be controlled together by one control circuit, which enables reduction in costs. Even the different types of LED boards18having different long-side dimensions and the number of mounted LEDs17have the substantially identical short-side dimension and alignment pitch of the LEDs17.

By preparing plural types of LED boards18having different long-side dimensions and the number of mounted LEDs17and appropriately using the different types of LED boards18in combination, following effects can be obtained. In other words, various types of liquid crystal display devices10of different screen sizes can easily be manufactured by appropriately selecting use/nonuse of each type of the LED board18and changing the number of each type of the LED boards18according to each screen size. As compared to the case where the dedicated LED board having the same long-side dimension as the long-side dimension of the chassis14is prepared for each screen size, the number of types of necessary LED boards18can be significantly reduced and therefore, manufacturing costs can be reduced. Specifically, by adding an eight-mounted type LED board that mounts eight LEDs17thereon to the above-mentioned two types of LED boards18(the five-mounted type and the six-mounted type) and appropriately using the three types of LED boards18in combination, each of the liquid crystal display devices10having the screen size of 26 inches, 32 inches, 37 inches, 40 inches, 42 inches, 46 inches, 52 inches and 65 inches can easily be manufactured.

The diffuser lenses19are made of a synthetic resin material (e.g. polycarbonate and acrylic) that is substantially transparent (highly light transmissive) and has a higher refractive index than air. As shown inFIG. 7,FIG. 8andFIG. 12, the diffuser lenses19each have a predetermined thickness, are formed to be substantially circular in a plan view, and are attached so as to cover the respective LEDs17from the front side of the LED board18, that is, so as to overlap with the respective LEDs17in a plan view. The diffuser lenses19can emit highly directive light from the LEDs17while diffusing the light. That is, since directivity of the light emitted from the LEDs17is reduced through the diffuser lenses19, even when the interval of the adjacent LEDs17is set large, an area between the LEDs17is hard to be visually recognized as a dark place. Thereby, the number of installed LEDs17can be reduced. Each diffuser lens19is located to be substantially concentric with each LED17in a plan view. Each diffuser lens19has sufficiently larger dimensions in the X-axis direction and in the Y-axis direction than each LED17. Although the diffuser lens19has a smaller dimension in the X-axis direction than the LED board18, the diffuser lens19has a larger dimension Y-axis direction than the LED board18. Accordingly, both ends of the diffuser lens19in the Y-axis direction each protrude outward by a predetermined dimension from the LED board18in the Y-axis direction.

In each of the diffuser lenses19, a surface that faces the back side and is opposite to the LED board18is alight incidence surface19aon which light from the LED17is incident, while a surface that faces the front side and is opposite to the optical member15is a light emitting surface19b. As shown inFIGS. 7 and 8, the light incidence surface19aextends in parallel to a plate surface of the LED board18(the X-axis direction and the Y-axis direction) as a whole, but has an inclined surface obtained by forming a light incidence-side concave portion19cin an area where the light incidence surface19aand the LED17overlap with each other in a plan view. The light incidence-side concave portion19cis substantially conical, is located to be almost concentric with the diffuser lens19and is opened toward the back side, that is, the LED17. The light incidence-side concave portion19chas the largest diameter at its opened end facing the LED17, which is larger than the diameter of the LED17, and becomes smaller toward the front side in diameter continually and gradually, and finally becomes the smallest at its end of the front side. The light incidence-side concave portion19chas a substantially inverted V-shaped cross section and a circumferential surface thereof is inclined relative to the Z-axis direction. The inclined surface is inclined so that the end of the front side crosses the optical axis LA of the LED17. Accordingly, light emitted from the LED17and entering into the light incidence-side concave portion19cis incident into the diffuser lens19through the inclined surface. At this time, the incident light is refracted away from the center, that is, in a wide angle, by an inclined angle of the inclined surface relative to the optical axis LA and is incident into the diffuser lens19.

The light incidence surface19aof the diffuser lens19has attachment shaft portions19dat positions outer of the light incidence-side concave portion19cin the radial direction. The attachment shaft portions19dprotrude toward the LED board18and serve as attachment structure of the diffuser lens19to the LED board18. Three attachment shaft portions19dare located closer to an outer edge than the light incidence-side concave portion19cin the diffuser lens19, and a line connecting the attachment portions is substantially equilateral-triangular in a plan view. By fixing each of front ends of the attachment shaft portions19dto the LED board18with an adhesive or the like, the diffuser lens19can be fixedly attached to the LED board18. The diffuser lens19is fixed to the LED board18through the attachment shaft portions19dso as to have a predetermined gap between the light incidence surface19aand the LED board18. This gap allows incidence of light from a space outer of the diffuser lens19in a plan view. In the above-mentioned attachment state, a front end of the LED17protruding from the LED board18enters into the light incidence-side concave portion19c.

The light emitting surface19bin the diffuser lens19is shaped like a substantially flat spherical surface. Thereby, the diffuser lens19can emit light while refracting the light on an interface with an external air layer in a direction away from the center, that is, in a wide angle. The light emitting surface19bhas a light-emitting side concave portion19e. The light-emitting side concave portion19eis formed in an area where the light emitting surface19boverlaps with the LED17in a plan view. The light-emitting side concave portion19eis substantially bowl-like and is shaped like a substantially flat sphere having a circumferential surface inclined downward to the center. An angle that a tangent line to the circumferential surface of the light-emitting side concave portion19eforms with the optical axis LA of the LED17is set to be relatively larger than an angle that the inclined surface of the light incidence-side concave portion19cforms with the optical axis LA. The area where the light emitting surface19boverlaps with the LED17in a plan view receives extremely larger light amount from the LED17than the other area and therefore, its brightness tends to locally become high. However, by forming the light-emitting side concave portion19ein that area, it becomes possible to emit most of the light from the LED17while refracting the light in a wide angle, or reflect a part of the light from the LED17toward the LED board18. Thereby, it is possible to prevent the brightness of the area where the light emitting surface19boverlaps with the LED17from locally becoming high, which is preferable for prevention of uneven brightness.

Next, the reflection sheet21will be described. The reflection sheet21is constituted by a chassis reflection sheet22that covers the almost the entire inner surface of the chassis14and a board reflection sheet23that covers each of the LED boards18. The reflection sheets22and23are each made of synthetic resin, and have a surface of white color having a high light reflectance. The reflection sheets22and23extend in the chassis14along the bottom plate14a(LED board18).

First, the chassis reflection sheet22will be described. As shown inFIG. 3, most part of the chassis reflection sheet22on the center side, which extends along the bottom plate14aof the chassis14, is a body portion22a. A lens insertion hole22bconfigured to pass each LED17arranged in the chassis14as well as each diffuser lens19covering the LED17therethrough is formed through the body portion22a. The plurality of lens insertion holes22bis arranged in parallel at positions where the lens insertion holes22boverlap with the LEDs17and diffuser lenses19on the body portion22ain a plan view in a matrix. As shown inFIG. 6, each lens insertion hole22bis circular in a plan view and has a larger diameter than the diffuser lens19. Thereby, when the chassis reflection sheet22is installed in the chassis14, the diffuser lenses19can be inserted into the respective lens insertion holes22birrespective of presence or absence of dimensional error. Since the chassis reflection sheet22covers regions between adjacent diffuser lenses19and regions on the outer circumferential side in the chassis14as shown inFIG. 3, light toward each of the regions can be reflected toward the optical member15. Further, as shown inFIGS. 4 and 5, outer circumferential portions of the chassis reflection sheet22rise so as to cover the side plates14cand the receiving plates14dof the chassis14, and portions placed on the receiving plates14dare sandwiched between the chassis14and the optical member15. A part of the chassis reflection sheet22connecting the body portion22ato a part placed on the receiving plate14dis inclined.

Meanwhile, the board reflection sheet23has, as shown inFIG. 12, almost the same outer shape as the LED board18, that is, is rectangular in a plan view. As shown inFIGS. 7 and 8, the board reflection sheet23is arranged so as to overlap with the front side surface of the LED board18, and is opposite to the diffuser lens19. That is, the board reflection sheet23is interposed between the diffuser lens19and the LED board18. Accordingly, light returned from the diffuser lens19to the LED board18and light entering from a space outer of the diffuser lens19in a plan view into a space between the diffuser lens19and the LED board18can be reflected toward the diffuser lens19by the board reflection sheet23again. As a result, light utilization efficiency can be enhanced, thereby increasing brightness. In other words, even when the number of installed LEDs17is reduced to cut costs, sufficient brightness can be obtained.

As shown inFIG. 12, the board reflection sheet23has the almost same long-side dimension as the LED board18and has a larger short-side dimension than the LED board18. Further, as shown inFIGS. 6 and 8, the short-side dimension of the board reflection sheet23is larger than the diameter of the diffuser lens19and the lens insertion hole22bin the chassis reflection sheet22. Accordingly, the edge of the lens insertion hole22bin the chassis reflection sheet22can be placed on the board reflection sheet23from the front side. Thereby, the chassis reflection sheet22and the board reflection sheet23are continuously arranged in the chassis14without any gap in a plan view, and the chassis14or the LED board18is hardly exposed from the lens insertion hole22btoward the front side. Therefore, light in the chassis14can be efficiently reflected toward the optical member15, which is extremely preferable for improvement of brightness. The board reflection sheet23includes LED insertion holes23athat pass the respective LEDs17therethrough and shaft portion insertion holes23bthat pass the respective attachment shaft portions19dof the diffuser lens19therethrough at overlapping positions in a plan view.

Next, the board holding member20will be described below. The board holding member20is classified into two types: a multifunctional board holding member20B that has a supporting function of supporting the optical member15in addition to the holding function of holding the LED board18and a monofunctional board holding member20A that has the supporting function, but does not have the holding function. Hereinafter, when the board holding member20needs to be distinguished, a subscript A is added to the reference numeral of the monofunctional board holding member, a subscript B is added to the reference numeral of the multifunctional board holding member and no subscript is added to the holding member that is not distinguished and is collectively called.

First, arrangement of the board holding members20in the chassis14will be described. As shown inFIG. 3, multiple board holding members20are arranged on the bottom plate14aof the chassis14. Describing in detail, given that the X-axis direction (the long-side direction of the chassis14and the LED board18) is the row direction and the Y-axis direction (the short-side direction of the chassis14and the LED board18) in the bottom plate14a, the board holding members20are arranged in the row and column directions (arranged in a matrix). Each board holding member20is located at an overlapping position with each LED board18in a plan view and between the adjacent diffuser lenses19(LEDs17). Accordingly, the board holding members20are arranged like the above-mentioned diffuser lenses19and the LEDs17. Since one board holding member20is arranged in a region between the adjacent diffuser lenses19(LEDs17) on the LED board18, the diffuser lenses19(LEDs17) and the board holding members20are alternately arranged in the substantially X-axis direction. Specifically, the four board holding members20are attached to each LED board18. On the six-mounted type of LED board18, the board holding members20are arranged at positions other than the center position in the long-side direction in the regions between the adjacent diffuser lenses19(LEDs17), and in the five-mounted type of LED board18, the board holding members20are arranged in all of the regions between the adjacent diffuser lenses19(LEDs17).

The board holding members20, as described above, are arranged in the chassis14in a matrix. Among them, as shown inFIG. 3, the plurality of (specifically, 14 in total) multifunctional board holding members20B is intermittently arranged in a zig-zag manner, and the monofunctional board holding members20A are arranged at other positions. Describing in detail, in the center-side region of the chassis14in the X-axis direction (region where the five-mounted type LED board18is arranged), the four multifunctional board holding members20B are arranged at positions near the center of each LED board18in the long-side direction in a zigzag manner in a plan view. In the both end-side region of the chassis14in the X-axis direction (where the six-mounted type LED board18is arranged), the five multifunctional board holding members20B are arranged at ends of the LED board18in the long-side direction in a zigzag manner in a plan view. As described above, the plurality of multifunctional board holding members20B is appropriately distributed in a plane of the bottom plate14aof the chassis14. The monofunctional board holding members20A are attached to all of the LED boards18in the chassis14, while the multifunctional board holding members20B are attached at positions corresponding to certain LED boards18.

Next, detailed configuration of the board holding member20will be described. Although the board holding member20is classified into two types as described above, most of the configuration is common and the common configuration will first be described. The board holding member20is made of synthetic resin such as polycarbonate and has a surface of white color having a high light reflectance. As shown inFIG. 9, the board holding member20includes a body portion24along the bottom plate14aof the chassis14and the plate surface of the LED board18, and an attachment portion25that is protruded from the body portion24toward the back side, that is, toward the chassis14and is fixed to the chassis14. Then, the board holding member20according to this embodiment is rotated about the rotational axis along the Z-axis direction along the plate surface of the bottom plate14aof the chassis14. Thereby the board holding member20is rotationally displaced between a holding position (position shown inFIGS. 9 and 10) at which the attachment portion25overlaps with an edge of the attachment hole14ein the chassis14in a plan view and sandwiches the edge of the attachment hole14ebetween the attachment portion25and the body portion24and a non-holding position (position shown inFIGS. 20 and 21) at which the attachment portion25does not overlap with the edge of the attachment hole14ein a plan view and attaching and detaching of the attachment portion25from the attachment hole14eis allowed. In this embodiment, by rotating the board holding member20, the board holding member20can be held at the chassis14and the holding state of the board holding member20at the chassis14can be released.

As shown inFIGS. 13 to 16, the body portion24is substantially circular in a plan view, and is shaped like a plate extending substantially straight in the X-axis direction and the Y-axis direction. As shown inFIG. 6, the body portion24has the almost same diameter as the short-side dimension (dimension in the Y-axis direction) of the LED board18. The body portion24is attached at an overlapping position with the LED board18in a plan view, thereby holding the LED board18between the body portion24and the bottom plate14aof the chassis14. Since the body portion24is attached in the state where the reflection sheets22and23are previously arranged on the front side of the LED board18, the body portion24can sandwich the LED board18and the reflection sheets22and23together (FIGS. 7 and 9).

Describing in detail, as shown inFIG. 6, the body portion24is located so that its center aligns with the center of the LED board18in the short-side direction. Accordingly, the body portion24can pinch the LED board18between the body portion and the chassis14over the entire length in the short-side direction. At this time, both outer ends of the body portion24in the Y-axis direction substantially align with both outer ends of the LED board18in the short-side direction. That is, the body portion24overlaps with the LED board18almost entirely in a plan view, thereby being prevented from extending outside of the LED board18. The diameter of the body portion24is set to be smaller than the interval (alignment pitch) between the adjacent diffuser lenses19(LEDs17) in the X-axis direction. The body portion24is arranged in the region between the adjacent diffuser lenses19in the X-axis direction of the LED board18, which is, a non-luminous part Of the LED board18, and does not overlap with the LED17in a plan view. Describing in more detail, the body portion24is located at a midpoint of the diffuser lenses19that are adjacent in the X-axis direction. Thus, since the distances between the body portion24and the adjacent LEDs17in the X-axis direction can be made almost equal to each other, optical effects of light emitted from the LEDs17on the body portion24can be made almost equal to each other. In this embodiment, since the interval between LEDs17is made sufficiently large by using the diffuser lens19as described above, the board holding member20is arranged in the space and fixes the LED board18.

Next, the attachment portion25together with the attachment hole14ein the chassis14will be described. As shown inFIGS. 14 and 16, the attachment portion25is substantially elliptical in a plan view, and extends in one direction. As shown inFIG. 6, like the attachment portion25, the attachment hole14eis substantially elliptical in a plan view, its long-side direction aligns with the X-axis direction and the short-side direction aligns with the Y-axis direction. That is, the attachment hole14ehas a longitudinal shape having the long-side direction coinciding with the long-side direction of the LED board18. These attachment portion25and attachment hole14eare noncircular (shape other than circular symmetric shape), and have rotationally symmetric shape of 2-fold symmetry. Both ends of the ling-side of the attachment portion25and the attachment hole14eare substantially semicircular in a plan view, and their circumferential surfaces are circular arcuate surfaces.

The attachment hole14eis formed to be larger than the attachment portion25in a plan view. Accordingly, in the state where the long-side direction of the attachment portion25aligns with the long-side direction of the attachment holes14e(the long-side direction of the attachment portion25aligns with the X-axis direction), the attachment portion25can be inserted into or pulled out of the attachment hole14e. In the state where the long-side direction of the attachment portion25aligns with the long-side direction of the attachment holes14eand the attachment portion25is inserted into the attachment hole14e, the board holding member20is located at the above-mentioned non-holding position, and the attachment portion25is entirely arranged in the attachment hole14ein a plan view, and is not engaged with the edge of the attachment hole14e(FIGS. 19 to 21). When the board holding member20is rotated from the non-holding position by a predetermined angle (angle other than an integral multiple of 180 degrees) such that the long-side direction of the attachment portion25intersects (does not match) the long-side direction of the attachment hole14e, the board holding member20is located at the above-mentioned holding position, apart of the attachment portion25overlaps with the edge of the attachment hole14ein a plan view and the overlapping part of the attachment portion25(holding portion25bdescribed later) is engaged with the edge of the attachment hole14efrom the back side (refer toFIGS. 6 and 9). Although the holding position includes the position where the board holding member20is rotated from the non-holding position by any angle other than the integral multiple of 180 degrees, in terms of stability of the holding state, the state where the board holding member20is rotated from the non-holding position by 90 degrees is most preferable (state shown inFIGS. 6 and 9). The plurality of attachment holes14eis arranged in parallel at the attachment positions of the board holding members20on the bottom plate14aof the chassis14in the X-axis direction and the Y-axis direction in a matrix.

As shown inFIG. 9, the attachment portion25includes an shaft portion25aprotruded from a back side surface of the body portion24toward the back side and a holding portion25bprotruded from the shaft portion25aalong the body portion24, and is shaped like an inverted T in a side view. The shaft portion25ais substantially shaped like a cylinder having an axial direction as the Z-axis direction and constitutes the rotational axis (rotating center) of the board holding member20. That is, the board holding member20is rotated about an axial line (Z axis) of the shaft portion25ain attaching and detaching with respect to the chassis14. As shown inFIGS. 14 and 16, the shaft portion25ahas a circular cross section along the X-axis direction and the Y-axis direction (direction along the plate surfaces of the body portion24and the chassis14), and its outer circumferential surface is a circular arcuate surface. The shaft portion25ais arranged at the center of the body portion24and is concentric with the body portion24. Accordingly, a rotational track of an outer circumferential end of the circular body portion24exists only on the same circumference of a circle. Further, since the shaft portion25aexists at the center of the body portion24on the back side, by viewing the body portion24from the front side, the position of the rotational axis of the board holding member20can easily be recognized.

As shown inFIGS. 14 and 16, the outer shape of the holding portion25baligns with that of the attachment portion25. That is, the holding portion25bis substantially elliptical (longitudinal shape) in a plan view, which is noncircular (shape other than circular symmetrical shape) and rotationally symmetric shape of 2-fold symmetry. The short-side dimension of the holding portion25bis set to be almost equal to the diameter of the shaft portion25a. Accordingly, the outer circumferential surface of the shaft portion25ais partially in flush with both long-side outer surface of the holding portion25b. The shaft portion25ais arranged in the region where the holding portion25bis formed in a plan view, and thus, is not projected outward from the outer edge of the holding portion25b. The center of the holding portion25bin the long-side direction is connected to a protruding front end of the shaft portion25asuch that the holding portion25bis symmetrical about the shaft portion25a. In other words, the holding portion25bis constituted by a pair of cantilevered plate pieces25b1protruded from the circumferential surface of the protruding front end of the shaft portion25ain mutually opposite directions. Accordingly, in the holding position, a pair of the plate pieces25b1forming the holding portion25bis engaged with parts of the edge of the attachment hole14e, which are located with an interval of 180 degrees.

The attachment portion25is located so as to overlap with the LED board18in a plan view. For this reason, a through hole18bthat passes the attachment portion25therethrough is formed in the LED board18. As shown inFIG. 11, the through hole18bis arranged between the adjacent LEDs17(diffuser lenses19) on the LED board18, that is, at the non-overlapping position with the LED17(diffuser lens19) in a plan view. The through hole18bis shaped like an ellipse having the almost same planar shape and dimension as those of the attachment hole14eabove, and communicates with the attachment holes14e. That is, the through hole18bhas a longitudinal shape parallel to the X-axis direction, that is, the long-side direction of the LED board18and the extending direction of the wiring patterns WP. Accordingly, the short-side dimension of the LED board18can be kept small while arranging a pair of the wiring patterns WP so as to cross the through hole18bin the LED board18in the Y-axis direction. As shown inFIGS. 7 and 9, since the edge of the through hole18bin the LED board18entirely overlaps with the edge of the attachment hole14ein a plan view, the chassis14and the LED board18are sandwiched between the body portion24and the holding portion25bin the board holding member20located at the holding position. As shown inFIG. 7,FIG. 9andFIG. 12, communicating holes22cand23cthat are configured to communicate with the through holes18band pass the fixed portion25therethrough are formed in the reflection sheets22and23sandwiched between the body portion24and the LED board18so as to overlap with the through holes18bin a plan view. As a result, each of the reflection sheets22and23together with the chassis14and the LED board18are sandwiched between the body portion24and the holding portion25bin the board holding member20located at the holding position.

The plurality of through holes18bof the above-mentioned shape corresponding to the attachment positions of the board holding members20is provided in each LED boards18. The plurality of through holes18bis classified into two types that are different from each other in size in a plan view. Describing in detail, as shown inFIG. 11, the through holes18bare constituted by one small through hole18bS that is relatively small in a plan view and a plurality of (three in the LED board inFIG. 11) large through holes18bL that is relatively large in a plan view. Similarly, as shown inFIG. 12, the communicating holes22cand23cin the reflection sheets22and23each are constituted by one small communicating hole22cS and23cS that are relatively small in a plan view and correspond to the small through hole18bS, and the plurality of large communicating holes22cL and23cL that is relatively large in a plan view and correspond to the large through hole18bL. Hereinafter, when the through hole18band the communicating holes22cand23cneed to be distinguished, a suffix S is added to the reference numerals of small ones, and a suffix L is added to reference numerals of large ones. When these holes are not distinguished and collectively referred, no suffix is added to their reference numerals.

As shown inFIGS. 9 and 10, each of the small through hole18bS and the small communicating holes22cS and23cS are slightly larger than the attachment portion25in a plan view, and a clearance between each of the holes and the attachment portion25is extremely small. Accordingly, by inserting the attachment portion25into the small through hole18bS and the small communicating holes22cS and23cS, the attachment portion25can position the LED board18and the reflection sheets22and23in the X-axis direction and the Y-axis direction. Meanwhile, each of the large through hole18bL and the large communicating holes22cL and23cL are larger than each of the small through hole18bS and the small communicating holes22cS and23cS, resulting that the clearance between each of the holes and the attachment portion25is relatively large. One small through hole18bS, one small communicating hole22cS, and one small communicating hole23cS are arranged corresponding to each LED board18, the plurality of large through holes18bL, the plurality of large communicating hole22cL and the plurality of large communicating hole23cL are arranged corresponding to each LED board18. Accordingly, even when the LED board18and the reflection sheets22and23are thermally expanded or thermally contracted, the large clearance between the attachment portion25and each of the large through hole18bL and the large communicating holes22cL and23cL can absorb the expansion and contraction of the LED board18and the reflection sheets22and23. As a result, deformation such as warp or flexion of the LED board18and the reflection sheets22and23is hard to occur.

Further, as shown inFIGS. 7 and 9, the body portion24is provided with a contact portion26that is protruded toward the back side, that is, toward the reflection sheet21(the LED board18, whereas the chassis14) and contacts with the reflection sheet21. The contact portion26is configured to contact with the chassis reflection sheet22of the reflection sheet21to directly press the chassis reflection sheet22from the front side as well as indirectly press the board reflection sheet23and the LED board18from the front side through the chassis reflection sheet22. Since the contact portion26is partially protruded from the back side surface of the body portion24(surface facing the chassis reflection sheet22), as compared to the case where the entire back side surface of the body portion contacts with the chassis reflection sheet22, the contact area with the chassis reflection sheet22is smaller. In the state where the contact portion26is in contact with the chassis reflection sheet22, the back side surface of the body portion24floats from the chassis reflection sheet22and is not in contact with the chassis reflection sheet22. A gap C corresponding to the protruding dimension of the contact portion26is ensured between the back side surface of the body portion24and the front side surface of the chassis reflection sheet22.

As shown inFIGS. 14 and 16, the contact portion26is located in the body portion24away from the attachment portion25, in particular, in the outer edge of the body portion24. That is, it can be said that the contact portion26is located at the position furthest from the attachment portion25in the body portion24. In the body portion24according to this embodiment, a part from the attachment portion25to the contact portion26has predetermined elasticity and thus, can be elastically deformed depending on stress applied. The pairs of contact portions26(four in total) are provided at each of positions across the shaft portion25aof the attachment portion25in the body portion24. Describing in detail, the contact portions26are each arranged at intervals of about 90 degrees in the body portion24, that is, on two straight lines that pass the centers of the body portion24and the attachment portion25and are orthogonal to each other. That is, the contact portions26are arranged symmetrically about the shaft portion25aof the attachment portion25in the body portion24. Accordingly, the distances between the shaft portion25aof the attachment portion25and the contact portions26are the same as one another. The two straight lines connecting the diagonally disposed contact portions26to each other coincide with the long-side direction and the short-side direction of the attachment portion25. It can be said that each contact portion26is a point when viewing the plate surface of the body portion24in a plan view. Thus, since the contact points of the board holding member20with the chassis reflection sheet22are distributed in the plate surface of the body portion24at regular intervals in a well-balanced manner, the board holding member20can be stably supported to the chassis reflection sheet22without causing rattling (FIG. 6).

As shown inFIGS. 7 and 9, each contact portion26is almost hemispherical as a whole, and its circumferential surface (contact surface with the chassis reflection sheet22) is formed of a spherical surface. Accordingly, each contact portion26is in point-contact with the chassis reflection sheet22. As a result, the contact area of each contact portion26with the chassis reflection sheet22is minimum.

Next, difference between the two types of board holding members20in configuration will be described. As shown inFIGS. 7 and 9, a gripping portion27protruded toward the front side is provided on the front side surface of the body portion24of the monofunctional board holding member20A. The operator can perform the attaching and detaching operation of the monofunctional board holding member20A while gripping the gripping portion27. As shown inFIG. 13, the gripping portion27has a longitudinal shape extending in one direction and is substantially rectangular (polygonal) in a plan view. For this reason, the long-side direction and the short-side direction of the gripping portion27can be varied with rotation of the monofunctional board holding member20A. The long-side direction of the gripping portion27aligns with the long-side direction of the attachment portion25. Accordingly, when viewing the board holding member20from the front side, by visually recognizing the outer shape of the gripping portion27, the long-side direction and the short-side direction of the attachment portion25on the back side can easily be recognized. The gripping portion27is located at the center of the body portion24and is concentric with the body portion24. Accordingly, the gripping portion27is concentric with the shaft portion25aof the attachment portion25and the rotating center of the board holding member20. The long-side dimension of the gripping portion27is set to be smaller than the diameter of the body portion24. Accordingly, the outer edge (outer circumferential surface) of the gripping portion27is arranged inner than the outer edge (outer circumferential surface) of the body portion24. As shown inFIG. 7, the gripping portion27has a substantially triangular cross section cut along the short-side direction, and both long-side surfaces are inclined. That is, it can be said that the gripping portion27is tapered toward its protruding end.

As shown inFIG. 9, an inclined surface24ais formed on the outer circumference of the body portion24of the monofunctional board holding member20A. The inclined surface24ais inclined downward from the center to the outer end of the body portion24, thereby eliminating or reducing the step that can be generated between the body portion24and the chassis reflection sheet22. As a result, the outer edge of the body portion24(boundary between body portion24and the reflection sheet21) is hard to be visually recognized as uneven brightness through the optical member15. Although not shown, the inclined surface24amay be provided at the multifunctional board holding member20B.

As shown inFIGS. 7 and 9, a supporting portion28that is protruded toward the front side and is configured to support the optical member15from the back side is provided on the front side surface of the body portion24of the multifunctional board holding member20B. In attaching and detaching the multifunctional board holding member20B, the operator can perform the attaching and detaching operation while gripping the supporting portion. The supporting portion28is conical as a whole. Describing in detail, the supporting portion28is tapered so that its cross section taken along the plate surface of the body portion24is circular and becomes gradually smaller from a protruding bottom end toward a protruding front end. The supporting portion28is configured to contact with the diffuser plate15aarranged closest to the back side (the LED17side) in the optical member15, thereby supporting the diffuser plate15aat a predetermined position. That is, the supporting portion28can restrict positional relationship between the optical member15and the LED17in the Z-axis direction (direction orthogonal to the surface of the optical member15) to be constant. The protruding dimension of the supporting portion28is almost equal to the distance between the front side surface of the body portion24and the back side surface of the diffuser15a, which is almost straight in the X-axis direction and the Y-axis direction. Accordingly, the supporting portion28is in contact with the substantially straight diffuser plate15a. The protruding front end of the supporting portion28as a contact part with the diffuser plate15ais rounded.

As shown inFIG. 15, the supporting portion28is located at the center of the body portion24and is concentric with the body portion24. Accordingly, the supporting portion28is concentric with the shaft portion25aof the attachment portion25and the rotating center of the board holding member20. In other words, the supporting portion28is located so as to overlap with the shaft portion25aof the attachment portion25arranged on the back side in a plan view. In particular, since the supporting portion28has the similar circular sectional shape as the shaft portion25a, when the operator performs the attaching and detaching operation of the multifunctional board holding member20B while gripping the supporting portion28, the attachment portion25can be inserted into the communicating holes22cand23c, the through hole18band the attachment holes14emore easily. The outer diameter of the protruding bottom end of the supporting portion28is set to be smaller than both the short-side dimension of the body portion24and the short-side dimension of the LED board18. Accordingly, the outer edge (outer circumferential surface) of the supporting portion28is located inner than the outer edge (outer circumferential surface) of the body portion24.

This embodiment has the above-mentioned configuration, and its action will be described. The liquid crystal display device10shown inFIGS. 4 and 5is manufactured by separately manufacturing the liquid crystal panel11and the backlight unit12and assembling them by use of the bezel13or the like. Especially, the assembling operation in manufacturing the backlight unit12will be described in detail.

In this embodiment, prior to assembling of each component to the chassis14, LEDs17, the board reflection sheet23and the diffuser lenses19are attached to the LED board18. Describing in detail, first, as shown inFIG. 11, after the LEDs17are mounted at predetermined positions on the LED board18, the board reflection sheet23is attached to cover the front side. At this time, each LED17on the board reflection sheet23is passed into each LED insertion hole23a. After that, as shown inFIG. 12, the diffuser lenses19are attached to the LED board18so as to cover the respective LEDs17. At this time, the attachment shaft portions19dof the diffuser lenses19are fixedly adhered to the LED board18with an adhesive through the respective shaft portion insertion holes23bin the board reflection sheet23. In this manner, a so-called light source unit U formed by uniting the LEDs17, the board reflection sheet23and the diffuser lenses19is manufactured on the LED board18.

Subsequently, an assembling operation of each component to the chassis14will be described. First, the light source units U are stored from the front side of the chassis14through the openings14band are arranged at predetermined attachment positions on the bottom plate14a. At this time, each through hole18bof the LED board18in the light source unit U is communicated with each attachment hole14eof the chassis14. Here, the adjacent LED boards18in the X-axis direction are electrically connected to each other by fitting the adjacent connector portions18awith each other. The operation of connecting the LED boards18aligned in the X-axis direction to each other is not necessarily performed within the chassis14, and may be performed outside of the chassis14. After all of the light source units U are arranged, the chassis reflection sheet22is arranged in the chassis14. At this time, each diffuser lens19is inserted into each lens insertion hole22bwhile positioning each lens insertion hole22bof the chassis reflection sheet22with respect to each diffuser lens19in the light source unit U (FIG. 3). When the chassis reflection sheet22is attached, the chassis reflection sheet22is placed on the almost entirely of the overlapping parts of the board reflection sheet23with the diffuser lenses19in a plan view from the front side (FIGS. 7 and 8). In particular, the entirety of the lens insertion hole22bin the chassis reflection sheet22is placed on the front side of the board reflection sheet23. As shown inFIGS. 17 and 18, the communicating hole22cin the chassis reflection sheet22is aligned with the communicating hole23cin the board reflection sheet23, the through hole18bof the LED board18and the attachment holes14eof the chassis14such that these holes are communicated with one another. After that, the operation of attaching the board holding member20is performed.

In assembling each board holding member20to the chassis14, in the monofunctional board holding member20A, the gripping portion27can be used as an operating part, and in the multifunctional board holding member20B, the supporting portion28can be used as an operating part. With this configuration, in assembling each board holding member20, the operator can operate the board holding member20while gripping the gripping portion27or the supporting portion28. While the board holding member20is stored in the chassis14through the opening14bfrom the front side of the chassis14and the long-side direction of the attachment portion25hidden on the back side through the body portion24is matched with the long-side direction of the corresponding communicating holes22cand23c, the through hole18band the attachment hole14e(refer toFIG. 19), the attachment portion25is inserted into each of the holes14e,18b,22cand23c. Since the gripping portion27and the supporting portion28are located so as to be concentric with the shaft portion25aof the attachment portion25, the operator can easily recognize the position of the attachment portion25from the front side, which is excellent in the workability.

When the attachment portion25is inserted into the attachment hole14eup to a predetermined depth, as shown inFIGS. 20 and 21, each contact portion26contacts with the chassis reflection sheet22, and the board holding member20is located at the non-holding position. At the non-holding position, the long-side direction of the attachment portion25aligns with the long-side direction of the attachment hole14e, and the holding portion25breaches the back side of the chassis14, but does not overlap with the edge of the attachment hole14e. By operating the gripping portion27or the supporting portion28from the non-holding position, the board holding member20can be rotated about the axial line (Z axis) of the shaft portion25aof the attachment portion25. Then, with rotation, the long-side direction of the attachment portion25intersects with the long-side direction of the attachment holes14eand the holding portion25bis rotationally displaced so as to overlap with the edge of the attachment hole14ein a plan view. At this time, it is preferred that the rotational angle of the board holding member20is 90 degrees from the non-holding position, and the long-side direction of the attachment portion25is orthogonal to the long-side direction of the attachment hole14e(refer toFIG. 6). Especially in the monofunctional board holding member20A, since the gripping portion27has a longitudinal shape, the operator can easily recognize the rotating state from the non-holding position by viewing the gripping portion27, thereby properly controlling the rotational angle of the monofunctional board holding member20A. In this manner, the board holding member20is located at the holding position and as shown inFIGS. 7 and 9, both the edge of the attachment hole14eof the chassis14and the edge of the through hole18bof the LED board18are sandwiched between the body portion24and the holding portion25bof the attachment portion25, thereby preventing the board holding member20from carelessly moving to the front side or the back side in the Z-axis direction. In this manner, the board holding member20is held at the holding position. The LED board18is held in the state of being sandwiched between the body portion24of the board holding member20and the chassis14, keeping the attachment state to the chassis14. The edges of the communicating holes22cand23cin the reflection sheets22and23are also sandwiched between the body portion24and the holding portion25b.

In the attachment state, as shown inFIGS. 7 and 9, each contact portion26contacts with the front side surface of the chassis reflection sheet22. Accordingly, in the attachment state, the spherical circumferential surface of each contact portion26is in point-contact with the chassis reflection sheet22, while the back side surface (surface facing the chassis reflection sheet22) of the body portion24floats from the chassis reflection sheet22and is not in contact with the chassis reflection sheet22, and the gap C corresponding to the protruding dimension of the contact portion26is ensured between the back side surface of the body portion24and the front side surface of the chassis reflection sheet22. Accordingly, the contact area of the board holding member20with the chassis reflection sheet22is extremely small, and is reduced as compared to the case where the entire back side surface of the body portion contacts with the chassis reflection sheet22. Conversely speaking, this means that the area of the part of the chassis reflection sheet22, which is not in contact with the board holding member20(part that is not pressed by the board holding member20), increases. In the attachment state, the board holding member20is stably supported by the four contact portions26symmetrically arranged with intervals of about 90 degrees. Describing in more detail, the contact portions26are arranged in the outer edge of the body portion24and thus, overlap with the outer edge of the LED board18in the short-side direction in a plan view. Accordingly, the outer edge of the LED board18in the short-side direction is supported by the contact portions26from the front side. The chassis reflection sheet22is directly pressed by the contact portions26, while the board reflection sheet23and the LED board18are indirectly pressed by the contact portions26through the chassis reflection sheet22.

After each board holding member20is attached to the chassis14as described above, the optical member15is attached to the chassis14so as to cover the openings14b. According to the specific attaching order of the optical member15, the diffuser15a, and then, the optical sheets15bare attached. As shown inFIGS. 4 and 5, the outer edge of the optical member15is received by the receiving plates14dof the chassis14and is supported by the supporting portion28of each multifunctional board holding member20B. Then, when the frame16is attached to the chassis14, the outer circumference edge of the optical member15is pinched between the frame16and the receiving plates14d. Thereby, manufacturing of the backlight unit12is completed. In assembling the manufactured backlight unit12and the liquid crystal panel11, the liquid crystal panel11is placed on the frame16and then, the bezel13is covered on the front side, and they are screwed together. Thereby, the liquid crystal panel11is pinched between the frame16and the bezel13and integrated with the backlight unit12, resulting that manufacturing of the liquid crystal display device10is completed.

In using the liquid crystal display device10manufactured as described above, each of the LEDs17provided in the backlight unit12is lit and an image signal is supplied to the liquid crystal panel11, thereby displaying a predetermined image on a display screen of the liquid crystal panel11. As shown inFIGS. 7 and 8, light emitted to each of the LEDs17is first incident on the light incidence surface19aof the diffuser lens19. At this time, most of light is incident on an inclined surface of the light incidence-side concave portion19cof the light incidence surface19aand thus, into the diffuser lens19while being refracted in a wide angle according to the inclined angle. Then, the incident light propagates in the diffuser lens19and is emitted from the light emitting surface19b. However, since the light emitting surface19bis a substantially flat spherical surface, light is emitted while being further refracted at an interface with the external air layer with a wider angle. Moreover, since the substantially bowl-like light-emitting side concave portion19eis formed in an area where the amount of light from the LED17is the largest in the light emitting surface19b, and its circumferential surface is a substantially flat spherical surface, light can be emitted while being refracted at the circumferential surface of the light-emitting side concave portion19ein a wide angle, or can be reflected toward the LED board18.

Since the highly directive light emitted from the LED17can be diffused in a wide angle by the diffuser lens19, in-plane distribution of the light reaching the optical member15can be made uniform. In other words, since the area between the adjacent LEDs17becomes hard to be visually recognized as the dark place by using the diffuser lens19, the interval between the LEDs17can be increased, thereby reducing the number of installed LEDs17while suppressing uneven brightness. Further, since the interval between the adjacent LEDs17can be increased by reducing the number of the LEDs17, the board holding member20can be arranged in the widened area, and the board holding member20can fix the LED board18. Since light returned to the LED board18is reflected toward the diffuser lens19by the board reflection sheet23and is incident on the diffuser lens19once, high brightness can be obtained.

Each LED17generates heat with lighting. Most of the heat generated from each LED17propagates to the chassis14through the LED board18that mounts the LED17thereon and is dissipated to air outside of the liquid crystal display device10. Considering heat radiation efficiency at this time, as closeness between the LED board18and the chassis14is higher, heat transfer performances of the LED board18and the chassis14improve and heat radiation efficiency becomes higher. Conversely, closeness between the LED board18and the chassis14is lower, heat transfer performances of the LED board18and the chassis14lower and heat radiation efficiency becomes lower. In this embodiment, heat radiation efficiency is improved by fixing the LED board18to the chassis14by the board holding member20and adopting following configuration. That is, since the outer edge of the LED board18in the short-side direction is pressed by each contact portion26of the board holding member20from the front side, the LED board18is stably held in close contact with the chassis14. Moreover, since the board holding member20has the attachment portion25at the center of the body portion24and the contact portions26in the outer edge, the LED board18is pressed by the center attachment portion25from the back side and by the contact portions26in the outer edge from the front side, thereby being stably held in a well-balanced manner. Furthermore, since the contact portions26are arranged at regular intervals in the body portion24, the LED board18can be pressed more stably in a well-balanced manner. As described above, since the LED board18is fixed stably to the chassis14in the close contact state by the board holding members20, heat transfer property to the chassis14is extremely high and therefore, heat radiation can be efficiently achieved. Therefore, since temperature inside the backlight unit12is hard to become high, it is possible to prevent lowering of light emission efficiency of each LED17and to stably obtain high brightness.

In using the liquid crystal display device10as described above, since each of the LEDs17in the backlight unit12is lit on or off, internal temperature environment changes and thus, each component of the liquid crystal display device10may be thermally expanded or thermally contracted. In the case where the chassis reflection sheet22and the board reflection sheet23among the components are thermally expanded or thermally contracted, when local deformation such as wrinkle or flexure is generated, unevenness is easy to occur in reflected light and uneven brightness occurs in light emitted from the backlight unit12, possibly exerting a negative effect on display quality. Further, in the case where the LED board18is thermally expanded or thermally contracted, when local deformation such as warp and flexure is generated, contact failure occurs in the connector portions18a, resulting in deficiency in controlling of lighting of the LED17. Such local deformation that can be generated in the reflection sheets22and23and the LED board18is likely to occur in proportion to the magnitude of the pressing force from the chassis14and the board holding member20and the applied area (contact area). In order to suppress local deformation, it is preferable to reduce the pressing force or the pressed area.

Then, in this embodiment, as shown inFIGS. 7 and 9, the board holding member20has the contact portions27, and the contact portions26of the board holding member20are in point-contact with the chassis reflection sheet22, thereby reducing the contact area with the chassis reflection sheet22. When the contact area is reduced, the area of the parts of the reflection sheets22and23and the LED board18, which are pressed by the board holding member20(parts overlapping with the contacts of the contact portions26in a plan view), decreases, and the area of the parts that are not pressed by the board holding member20(parts that do not overlap with the contacts of the contact portions26in a plan view increases. The parts pressed by the board holding member20are relatively hard to be expanded or contracted due to thermal expansion or thermal contraction (the degree of freedom in expansion and contraction is low), while the parts that are not pressed by the board holding member20are relatively easy to be expanded or contracted due to thermal expansion or thermal contraction (the degree of freedom in expansion and contraction is high). In this embodiment, since the area of the unpressed parts is increased, the reflection sheets22and23and the LED board18as a whole are easy to be expanded or contracted due to thermal expansion or thermal contraction, and flexion and warp that can be generated due to expansion and contraction is preferably absorbed by the unpressed parts, flatness as a whole is maintained, and flexion and warp of the reflection sheets22and23and the LED board18can be prevented from occurring locally. As a result, unevenness of light reflected by the reflection sheets22and23is hard to occur and therefore, it can be prevented that uneven brightness of light emitted from the backlight unit12occurs.

Moreover, the contact portions26are located in the body portion24away from the holding portion25bof the attachment portion25in a plan view. The contact portions26are portions applying the pressing force to the reflection sheets22and23and the LED board18from the front side (body portion24side), and the holding portion25bis a portion applying the pressing force to the reflection sheets22and23and the LED board18from the back side (chassis14side). Accordingly, by arranging the contact portions26and the holding portion25bto be shifted (offset) from each other in a plan view as described above, in the reflection sheets22and23and the LED board18, the positions at which the pressing force is applied from the front side (positions of the contact portion26) and the position at which the pressing force is applied from the back side (position of the holding portion25b) are similarly shifted from each other. Accordingly, concentration of the stress acted on the reflection sheets22and23and the LED board18from the front side and the back side can be prevented. Thus, since the pressing force acted on the reflection sheets22and23and the LED board18can be prevented from locally becoming large, the situation in which the degree of freedom in expansion and contraction of the parts pressed by the board holding member20becomes extremely low and therefore, the degree of freedom in expansion and contraction of the reflection sheets22and23and the LED board18as a whole can be increased.

Moreover, by arranging the contact portions27in the body portion24away from the holding portion25bin a plan view, following action and effect can be obtained. That is, in this embodiment, with the above-mentioned configuration, the part of the body portion24from the bottom portion25aof the attachment portion25to the contact portions26can be elastically deformed. Thus, for example, the protruding dimension of the attachment portion25from the body portion24is set so that when the attachment portion25is inserted into the attachment hole14eas shown inFIG. 22(non-holding position), the holding portion25bpartially enters into the attachment hole14e. With this configuration, by further pressing the gripping portion27or the supporting portion28from the state shown inFIG. 22toward the back side, the holding portion25bcan be brought to the back side of the chassis14while elastically deforming the part of the body portion24from the bottom end25aof the attachment portion25to the contact portions26. When the board holding member20is rotated from this state to the holding position, as shown inFIG. 23, the chassis14and the LED board18can be elastically sandwiched between the holding portion25band the elastically deformed body portion24. As a result, it can be prevented that the board holding member20is rotationally displaced from the holding position to the non-holding position carelessly and therefore, detaching of the board holding member20can be prevented. Further, since the LED board18can be elastically in close contact with the chassis14, heat radiation property can also be also improved.

By arranging the contact portions27in the body portion24away from the holding portion25bin a plan view, following action and effect can also be obtained. That is, when a dimensional error occurs in manufacturing of the board holding member20, for example, when the protruding dimension of the contact portion26from the body portion24is larger than a set value or the length of the attachment portion25is shorter than a set value, the pressing force acted on the reflection sheets22and23and the LED board18may become excessively large (than required). Thus, in this embodiment, since some elasticity is imparted to the part of the body portion24from the bottom end25aof the attachment portion25to the contact portions26, as shown inFIG. 23, the possibly increased pressing force can be absorbed by elastically deforming the part of the body portion24from the attachment portion25to the contact portions26. Thereby, it can be prevented that an excessive pressing force is applied from the contact portions26to the reflection sheets22and23and the LED board18. Therefore, the degree of freedom in expansion and contraction of the reflection sheets22and23and the LED board18can be ensured.

In this embodiment, the through hole18bin the LED board18and the communicating holes22cand23cin the reflection sheets22and23each include two types of holes of different dimensions in a plan view. This provides following action and effects. That is, since the clearance between each of the small through hole18bS and the small communicating holes22cS and23cS and the attachment portion25is extremely small, the LED board18and the reflection sheets22and23can be positioned in the X-axis direction and the Y-axis direction. On the contrary, since clearance between each of the large through hole18bL and the large communicating holes22cL and23cL and the attachment portion25is relatively large, even when the LED board18and the reflection sheets22and23are thermally expanded or contracted, the clearance held between the attachment portion25and each of the large through hole18bL and the large communicating holes22cL and23cL can absorb the expansion and contraction of the LED board18and the reflection sheets22and23. Further, since one small through hole18bS, one small communicating hole22cS and one small communicating hole23cS are provided in each LED board18, and other through holes18band communicating holes22cand23care all the large through hole18bL and the large communicating holes22cL and23cL, even when the LED board18and the reflection sheets22and23are thermally expanded or contracted, deformation such as flexion and warp can be prevented. As a result, unevenness of light reflected by the reflection sheets22and23is hard to occur and therefore, it can be prevented that uneven brightness of light emitted from the backlight unit12occurs.

In a lighting test performed in a manufacturing process of the liquid crystal display device10(backlight unit12), the LED board18itself or any LED17has a failure, the LED board18having the failure needs to be detached from the chassis14for replacement or repair of the LED board18. Also, when the LED board18or any LED17has a failure during use of the liquid crystal display device10or the liquid crystal display device10at the end of life is discarded, the LED board18needs to be detached from the chassis14. In such cases, various components are detached from the liquid crystal display device10according to a reverse procedure to the above-mentioned assembling procedure at manufacturing, and after completion of detaching the optical member15, the LED board18is detached from the chassis14. The operator rotates the board holding member20located at the holding position about the Z axis while gripping the gripping portion27or the supporting portion28. When the board holding member20reaches the non-holding position, engagement state (holding state) between the edge of the attachment hole14ein the chassis14and the holding portion25bis released. Thus, the board holding member20is detached by pulling up the board holding member20to the front side along the Z-axis direction. In this manner, the LED board18can be detached from the chassis.

As described above, the backlight unit12in this embodiment includes the LEDs17as light sources, the LED board18that mounts the LEDs17thereon, the chassis14that stores the LED board18therein and has the attachment holes14e, the body portion24that sandwiches the LED board18between the body portion24and the chassis14to hold the LED board18, and the board holding members20that each are protruded from the body portion24toward the chassis14and have the attachment portion25inserted into the attachment hole14e. Each board holding member20can be rotated along the plate surface of the chassis14between the holding position at which the attachment portion25overlaps with the edge of the attachment hole14ein a plan view and sandwiches the edge of the attachment hole14ebetween the attachment portion25and the body portion24, and the non-holding position at which the attachment portion25does not overlap with the edge of the attachment hole14ein a plan view and attaching and detaching of the attachment portion25from the attachment holes14eis allowed.

With this configuration, in order to attach the LED board18to the chassis14, in the state where the LED board18is stored in the chassis14, the attachment portion25of the board holding member20is inserted into the attachment hole14eof the chassis14and then, the board holding member20located at the non-holding position is rotated along the plate surface of the chassis14. Thus, the board holding member20reaches the holding position, and the attachment portion25overlaps with the edge of the attachment hole14ein a plan view and the edge of the attachment hole14eis sandwiched between the attachment portion25and the body portion24, resulting that the board holding member20is attached to the chassis14. In this state, the LED board18is sandwiched between the body portion24of the board holding member20and the chassis14, thereby achieving the attachment state to the chassis14. To detach the LED board18from the chassis14, by rotating the board holding member20located at the holding position, the attachment portion25reaches the non-holding position at which the attachment portion25does not overlap with the edge of the attachment hole14ein a plan view. Since detaching of the attachment portion25from the attachment holes14eis allowed at the non-holding position, the board holding member20can be detached from the chassis14. Thus, since the holding state of the LED board18by the board holding member20is released, the LED board18can be detached from the chassis14.

Conventionally, the LED board18is attached with screws. Thus, the workability tends to degrade as the workability of the screw attaching and detaching operation itself is poor. However, in this embodiment, by rotating the board holding member20along the plate surface of the chassis14between the non-holding position and the holding position, the LED board18can easily be held by the board holding member20or the holding state can easily be released, which is excellent in the workability in attaching and detaching the LED board18.

Since the board holding member20according to this embodiment holds the LED board18by holding the LED board18between the board holding member20and the chassis14, for example, when a failure exists in any LED17mounted on the LED board18and replacement or repair of the LED board18is required, it is need to detach each of the board holding member20and the LED board18from the chassis14. For example, in the case of a lamp clip holding a cold-cathode tube, only the cold-cathode tube needs to be detached. As compared to the case, the frequency of detaching the board holding member20tends to increase. Further, the number of LED boards18tends to increase with upsizing of the backlight unit12, and the number of board holding members20and the number of times of the attaching and detaching operation also increase with such upsizing. Under such circumstances, by improving the workability in attaching and detaching the board holding member20holding the LED board18, the workability in repairing the backlight unit12as well as the workability in the case of upsized backlight unit12can be remarkably improved.

Both the attachment portion25and the attachment hole14ehave a longitudinal shape. With this configuration, when the long-side direction of the attachment portion25aligns with the long-side direction of the attachment hole14e, the board holding member20is located at the non-holding position, and the long-side direction of the attachment portion25intersects the long-side direction of the attachment hole14e, the board holding member20is located at the holding position. As compared to the case where the attachment portion25and the attachment hole14ehave shape other than the longitudinal shape, such as a square, in a plan view, a large region of the attachment portion25that overlaps with the edge of the attachment hole14ein a plan view can be ensured at the holding position, thereby stably holding the board holding member20and the LED board18. Further, in the case where the attachment portion25is square in a plan view, when the board holding member20is rotated from the non-holding position by 90 degrees, the board holding member20is located at the non-holding position again. However, in this embodiment, even when the board holding member20is rotated from the non-holding position by 90 degrees, the board holding member20can be located at the holding position and therefore, the situation in which the board holding member20is carelessly detached is hard to occur.

The attachment portion25is located so as to overlap with the LED board18in a plan view. The LED board18, on the other hand, has the through hole18bthat communicates with the attachment hole14eand passes the attachment portion25therethrough, and the edge of the attachment hole14eand the edge of the through hole18bare sandwiched between the body portion24and the holding portion25b. With this configuration, since the edge of the through hole18bin the LED board18together with the chassis14are sandwiched between the body portion24and the holding portion25b, the LED board18can be held more stably.

The LED board18has a longitudinal shape and has the wiring patterns WP extending in the long-side direction, and the through hole18bhas a longitudinal shape parallel to the long-side direction of the LED board18. With this configuration, since the through hole18bhas a longitudinal shape parallel to the long-side direction of the LED board18, that is, the extending direction of the wiring patterns WP, as compared to the case where the through hole has a longitudinal shape orthogonal to the extending direction of the wiring patterns WP, in forming the through hole18band the wiring patterns WP in the LED board18, the short-side dimension of the LED board18can be reduced. Thereby, material costs of the LED board18can be cut and a space occupied by the LED board18in the chassis14can be reduced.

The LED board18has the plurality of through holes18b, and the through holes18bare constituted of the small through hole18bS that is relatively small in a plan view and the large through hole18bL that is relatively large in a plan view. With this configuration, the gap held between the attachment portion25inserted into the small through hole18bS and the inner surface of the small through hole18bS is smaller than the gap held between the attachment portion25inserted into the large through hole18bL and the inner surface of the large through hole18bL. Accordingly, the attachment portion25inserted into the small through hole18bS can properly position the LED board18. Since the larger gap held between the inner surface of the large through hole18bL and the attachment portion25can ensure a sufficient allowable expansion/contraction amount at the time when the LED board18is expanded or contracted due to thermal expansion or thermal contraction, deformation such as warp of the LED board18is hard to occur.

The reflection sheet21that reflects light is interposed between the body portion24and the LED board18, and the reflection sheet21has the plurality of communicating holes22cand23cthat each communicates with the attachment hole14eand the through hole18band pass the attachment portion25therethrough. The communicating holes22cand23care constituted by the small communicating holes22cS and23cS that are relatively small in a plan view and the large communicating holes22cL and23cL that are relatively large in a plan view. With this configuration, the gap held between the attachment portion25inserted into the small communicating holes22cS and23cS and the inner surfaces of the small communicating holes22cS and23cS is smaller than the gap held between the attachment portion25inserted into the large communicating holes22cL and23cL and the inner surfaces of the large communicating holes22cL and23cL. Accordingly, the attachment portion25inserted into the small communicating holes22cS and23cS can properly position the reflection sheet21. Since the larger gap held between the inner surfaces of the large communicating holes22cL and23cL and the attachment portion25can ensure a sufficient allowable expansion/contraction amount at the time when the reflection sheet21is expanded or contracted due to thermal expansion or thermal contraction, deformation such as warp of the reflection sheet21is hard to occur.

The LED board18has a longitudinal shape and mounts the plurality of LEDs17thereon in the long-side direction, and the body portion24is arranged in the region between the adjacent LEDs17on the LED board18in a plan view. With this configuration, the region between the adjacent LEDs17in the LED board18can be effectively used.

The body portion24is located at the midpoint, the point LED board18between the adjacent LEDs17in a plan view. With this configuration, since the distances between the body portion24and the adjacent LEDs17are almost equal to each other, optical effects of light emitted from the LEDs17on the body portion24can be made substantially uniform. As a result, unevenness of light emitted from the backlight unit12is hard to occur.

The body portion24is located at the center of the LED board18in the short-side direction in a plan view. With this configuration, the LED board18can be held more stably.

The circumferential surfaces of the attachment portion25and the attachment holes14einclude the circular arcuate surfaces in a plan view. With this configuration, in inserting or pulling the attachment portion25into or out of the attachment holes14e, the circular arcuate surfaces can facilitate the inserting/pulling operation, which is excellent in the workability at insertion/pulling-out.

The attachment portion25includes the shaft portion25athat is protruded from the body portion24toward the chassis14and serves as the rotational axis of the board holding member20, and the holding portion25bthat is protruded from the shaft portion25ain substantially parallel with the body portion24and is configured to sandwich the edge of the attachment hole14ebetween the holding portion25band the body portion24. With this configuration, the board holding member20can be rotated about the shaft portion25aof the attachment portion25as the rotational axis between the holding position and the non-holding position, thereby holding the edge of the attachment hole14ebetween the holding portion25band the body portion24or releasing the holding state.

The shaft portion25ais concentric with the body portion24. With this configuration, the operator can easily recognize the position of the rotational axis of the board holding member20by viewing the body portion24. Thereby, the workability in attaching and detaching the board holding member20can be improved.

The holding portion25bhas a pair of the plate pieces25b1protruded from the shaft portion25ain the mutually opposite directions. With this configuration, when the board holding member20is located at the holding position, since the plate pieces25b1of the holding portion25b, which are protruded from the shaft portion25ain the mutually opposite directions, sandwich the edge of the attachment hole14e, the LED board18can be held stably.

The holding portion25bis symmetric about the shaft portion25a. With this configuration, areas of the parts of the holding portion25b, which are protruded from the shaft portion25ain the mutually opposite directions, overlap with the edge of the attachment hole14ein a plan view are almost equal to each other, the LED board18can be held more stably.

The shaft portion25ais arranged in a region where the holding portion25bis formed in a plan view. With this configuration, the planar shape of the attachment holes14ecan be aligned with that of the holding portion25b. Thereby, the shape of the attachment holes14ecan be simplified.

The shaft portion25ahas a circular cross section. With this configuration, in rotating the board holding member20, since the shaft portion25ais hard to interfere with the edge of the attachment hole14e, the rotating operation can be smoothly achieved, which is excellent in the workability.

The body portion24is circular in a plan view. With this configuration, even when a shadow occurs due to the outer edge of the body portion24, the shadow is hard to be visually recognized from the outside, which is preferable to prevent uneven brightness.

The body portion24has the gripping portion27and the supporting portion28, as protrusion protruded toward the side opposite to the chassis14. With this configuration, when attaching and detaching the board holding member20to/from the chassis14, the operator can perform the attaching and detaching operation while gripping the gripping portion27and the supporting portion28, which are protruded from the body portion24toward the side opposite to the chassis14. Thereby, the workability in attaching and detaching the board holding member20can be further improved.

The gripping portion27has a longitudinal shape. With this configuration, the workability in rotating the board holding member20while gripping the gripping portion27can be improved. Moreover, the operator can easily recognize the rotating state of the board holding member20by viewing the gripping portion27.

Both the attachment portion25and the attachment holes14ehave a longitudinal shape, and the long-side direction of the gripping portion27aligns with the long-side direction of the attachment portion25. With this configuration, the operator can easily recognize the long-side direction and the short-side direction of the attachment portion25of longitudinal shape by viewing the gripping portion27. Thereby, the workability in attaching and detaching the board holding member20can be improved.

The gripping portion27and the supporting portion28are concentric with the rotating center of the board holding member20. With this configuration, the workability at the time when the operator performs the rotating operation while gripping the gripping portion27and the supporting portion28.

The gripping portion27and the supporting portion28are tapered. With this configuration, a shadow due to the gripping portion27and the supporting portion28is hard to occur, which is preferable to prevent uneven brightness.

The gripping portion27is polygonal in a plan view. With this configuration, as compared to the case where the gripping portion is circular in a plan view, the workability at the time when the operator performs the rotating operation while gripping the gripping portion27.

The outer edges of the gripping portion27and the supporting portion28are arranged inner than the outer edge of the body portion24in a plan view. With this configuration, as compared to the case where the outer edges of the gripping portion and the supporting portion are in flush with the outer edge of the body portion24, a shadow due to the gripping portion27and the supporting portion28is harder to occur, which is preferable to prevent uneven brightness.

The chassis14has the opening14bconfigured to emit light from the LEDs17and the optical member15is provided so as to face the LED board18and cover the opening14b. The supporting portion28can support the optical member15. With this configuration, by supporting the optical member15by means of the supporting portion28, it can be prevented that the optical member15is deformed so as to get close to the LED17.

The reflection sheet21that reflects light is interposed between the body portion24and the LED board18, and the contact portion26that is protruded toward the reflection sheet21and contacts with the reflection sheet21is provided on the opposite surface of the body portion24to the reflection sheet21. With this configuration, the reflection sheet21together with the LED board18can be held. Since the contact portion26that contacts with the reflection sheet21is protruded from the body portion24toward the reflection sheet21, as compared to the case where the counter surface of the body portion to the reflection sheet21entirely contacts with the reflection sheet21, the contact area of the board holding member20with the reflection sheet21can be reduced. Conversely speaking, the area of the reflection sheet21, which is not in contact with the board holding member20and is not pressed by the board holding member20, increases. The unpressed part is easier to expand or contract due to thermal expansion or thermal contraction that is caused by a change in thermal environment compared to the part that is in contact with the board holding member20and is pressed by the board holding member20. As the area of the unpressed part increases, the degree of freedom in expansion and contraction of the reflection sheet21as a whole improves. Thereby, deformation such as flexion and warp due to expansion and contraction can be prevented from locally occurring.

The contact portions26are located in the body portion24away from the attachment portion25. With this configuration, in the case where a dimensional error occurs during manufacturing of the board holding member20, for example, when the protruding dimension of the contact portion26from the body portion24is larger than a set value, the pressing force acted on the reflection sheet21may become excessively large. Even in such case, since the contact portions26are located in the body portion24away from the attachment portion25, the part of the body portion24from the attachment portion25to the contact portion26can be elastically deformed to absorb possibly increased pressing force. Thereby, it can be prevented that an excessive pressing force is applied from the contact portion26to the reflection sheet21and therefore, the degree of freedom in expansion and contraction of the reflection sheet21can be ensured. Moreover, when the body portion24is elastically deformed as described above, the chassis14is sandwiched between the body portion24and the holding portion25bby the elastic force. Thus, it can be prevented that the board holding member20is carelessly moved from the holding position to the non-holding position due to vibration or the like. Thereby, careless detaching of the board holding member20can be prevented.

The attachment portion25is arranged at the center of the body portion24, and the contact portion26is arranged in the outer edge of the body portion24. With this configuration, by arranging the attachment portion25at the center of the body portion24, the board holding member20can be stably held at the chassis14. In addition, by arranging the contact portion26in the outer edge of the body portion24, the maximum distance between the attachment portion25and the contact portion26can be obtained and therefore, the body portion24can be elastically deformed more easily. Thereby, absorption width of the dimensional error occurring in manufacturing of the board holding member20can be increased and therefore, the degree of freedom in expansion and contraction of the reflection sheet21can be ensured more stably.

At least a pair of the contact portions26is arranged in the body portion24so as to sandwich the attachment portion25therebetween. With this configuration, the pressing force can be applied to the reflection sheet21in a well-balanced manner and therefore, the reflection sheet21can be held while improving the degree of freedom in expansion and contraction of the reflection sheet21. Further, the body portion24can be elastically deformed in the shape of a bow between a pair of the contact portions26.

The contact portions26are located symmetrically about the attachment portion25. With this configuration, the pressing force can be applied to the reflection sheet21in a more-balanced manner.

The light source is the LED17. With this configuration, higher brightness and lower power consumption and the like can be achieved.

Although the first embodiment of the present invention has been described, the present invention is not limited to this embodiment and for example, may include the following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of First Embodiment>

A first modification example of the first embodiment will be described with reference toFIG. 24. Here, a gripping portion27-1of modified shape is shown.

As shown inFIG. 24, the gripping portion27-1has a trapezoidal cross section cut along its short-side direction. With this configuration, the thickness of the gripping portion27-1is larger than that of the gripping portion27in the first embodiment and thus, the strength is excellent.

<Second Modification Example of First Embodiment>

A second modification example of the first embodiment will be described with reference toFIG. 25. Here, a gripping portion27-2of modified shape is shown.

As shown inFIG. 25, the gripping portion27-2is substantially block-like as a whole, and its protruding front end is circular arcuate. That is, the width (dimension in the short-side direction) of the gripping portion27-2is uniform except for the protruding front end. Accordingly, the strength of the gripping portion27-2is more excellent than the gripping portion27described in the first embodiment, the width of which is continuously decreased.

<Third Modification Example of First Embodiment>

A third modification example of the first embodiment will be described with reference toFIG. 26. Here, a gripping portion27-3of modified shape is shown.

As shown inFIG. 26, a side surface of the gripping portion27-3along its long-side direction (Y-axis direction) is tapered in two stages. That is, in the gripping portion27-3, a protruding bottom end27aand a protruding front end27bhave side surfaces having different inclination angles, and the inclination angle of the side surface of the protruding bottom end27ais smaller than that of the side surface of the protruding front end27b. With this configuration, a shadow due to the gripping portion27-3is hard to occur, which is preferable to prevent uneven brightness.

<Fourth Modification Example of First Embodiment>

A fourth modification example of the first embodiment will be described with reference toFIG. 27. Here, a gripping portion27-4of modified shape is shown.

As shown inFIG. 27, a concave portion27cis formed on the side surface of the gripping portion27-4in its long-side direction (Y-axis direction). The concave portion27cis circular. With this configuration, the operator can easily grip the gripping portion27-4, which is excellent in the workability.

<Fifth Modification Example of First Embodiment>

A fifth modification example of the first embodiment will be described with reference toFIG. 28. Here, a supporting portion28-5of modified shape is shown.

As shown inFIG. 28, the supporting portion28-5is shaped like a quadrangular pyramid. That is, since the supporting portion28-5is rectangular (polygonal) in a plan view, when the operator performs the rotating operation while gripping the supporting portion28-5, slipping is hard to occur, improving the workability.

A second embodiment of the present invention will be described with reference toFIGS. 29 to 32. In the second embodiment, a body portion124and an attachment portion125, which have modified shape, in a board holding member120are shown. Overlapping description of the same configuration, actions and effects as those in the first embodiment is omitted.

As shown inFIGS. 29 and 30, the body portion124of the board holding member120is substantially elliptical in a plan view, and has a longitudinal shape extending in one direction. The long-side direction of the body portion124aligns with the short-side direction of the attachment portion125, and is orthogonal to the long-side direction of the attachment portion125. A pair of contact portions26are arranged each end of the body portion124in the long-side direction. The long-side dimension of the attachment portion125(holding portion125b) is set to be larger than the short-side dimension of the body portion124. Accordingly, both ends of the attachment portion125in the long-side direction are projected outward from both outer edge along the long-side direction of the body portion124, and the projecting portions125b1can be viewed from the front side. An attachment hole114ein a chassis114is formed to be larger than an attachment hole125in a plan view (FIG. 31).

To attach the board holding member120to the chassis114, as shown inFIG. 31, the attachment portion125is inserted into the attachment hole114ewhile the long-side direction of the attachment portion125is matched with the long-side direction of the attachment hole114e, and the board holding member120is located at the non-holding position. At the non-holding position, since the projecting portions125b1of the holding portion125bare exposed to the front side, the operator can visually recognize the projecting portions125b1. Further, both ends of the attachment hole114ein the long-side direction are also exposed to the front side. When being rotated from the non-holding position, the board holding member120is rotationally displaced such that the orientation of the body portion124changes and the projecting portions125b1overlap with an edge of the attachment hole114ein a plan view, resulting that the operator cannot visually recognize the projecting portions125b1. By viewing the body portion124and the projecting portions125b1, the rotating state of the board holding member120can easily be recognized. When the board holding member120is rotated from the non-holding position to the holding position by about 90 degrees, as shown inFIG. 32, the long-side direction of the body portion124substantially aligns with the long-side direction of the attachment hole114eand the attachment hole114eis entirely covered with the body portion124from the front side. As a result, the attachment hole114eis not exposed to the front side, thereby preventing light in the chassis114from leaking into the attachment hole114e.

As described above, according to this embodiment, the body portion124has a longitudinal shape. With this configuration, when the board holding member120is rotated between the holding position and the non-holding position, the rotating state of the board holding member120can easily be grasped by viewing the body portion124, which is excellent in the workability.

Both the attachment portion125and the attachment hole114ehave a longitudinal shape, and the long-side direction of the body portion124aligns with the short-side direction of the attachment portion125. With this configuration, the operator can easily recognize the long-side direction and the short-side direction of the attachment portion125of longitudinal shape by viewing the body portion124. Thereby, the workability in attaching and detaching the board holding member120can be improved.

The attachment portion125is projected outward from the outer edge of the body portion124in a plan view. With this configuration, the operator can easily recognize the rotating state of the board holding member120from the non-holding position by viewing the outer shape of the body portion124as well as the projecting portions125b1of the attachment portion125from the body portion241, which is extremely excellent in workability. Moreover, the attachment hole114einto which the attachment portion125is inserted can be covered with the body portion124of longitudinal shape at the holding position, thereby preventing exposure of the attachment hole114e.

An outer circumferential surface of the body portion124includes a circular arcuate surface that is circular arcuate in a plan view. With this configuration, even when a shadow occurs due to the outer edge of the body portion124of longitudinal shape, the shadow is hard to be visually recognized from the outside, which is preferable to prevent uneven brightness.

A third embodiment of the present invention will be described below with reference toFIG. 33orFIG. 34. In the third embodiment, a body portion224of a board holding member220has indicating portions29. Overlapping description of the same configuration, actions and effects as those in the first embodiment is omitted.

As shown inFIGS. 33 and 34, the body portion224of the board holding member220has the indicating portions29as indicators (marks) of the rotating state. The indicating portions29are arranged in the body portion224away from the rotating center of the board holding member220, specifically, arranged in the outer edge of the body portion224. Each indicating portion29is formed by partially cutting the body portion224. The pair of indicating portions29is arranged in the body portion224at angular intervals of 180 degrees, and a line connecting both the indicating portions29to each other passes the rotating center of the board holding member220and is parallel to the long-side direction of an attachment portion225. That is, the indicating portions29are located in the body portion224to be symmetrical about the rotating center. Further, the indicating portions29serve as marks for representing the long-side direction of the attachment portion225. When the board holding member220is rotated, the operator can easily recognize the rotating state of the board holding member220by viewing the indicating portions29, which is excellent in the workability. Although the multifunctional board holding member220is shown inFIGS. 33 and 34, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, the indicating portions29displaced with rotation of the board holding member220are provided in the body portion224at the positions shifted from the rotating center of the board holding member220. With this configuration, the operator can easily recognize the rotating state of the board holding member220by viewing the indicating portions29, which is excellent in the workability.

The indicating portions29are formed by partially cutting the body portion224. With this configuration, as compared to the case where the indicating portions29are formed by partially protruding the body portion224, the outer shape can be compact and material costs can be cut.

The indicating portions29are arranged in the outer edge of the body portion224. With this configuration, since the displacement amount of the indicating portions29with rotation can be ensured to the maximum, the operator can recognize the rotating state of the board holding member220more clearly, which is more excellent in the workability.

The pair of indicating portions29is arranged in the body portion224so as to be symmetrical about the rotating center of the board holding member220. With this configuration, the operator can recognize the rotating state of the board holding member220more clearly, which is more excellent in the workability.

The third embodiment of the present invention has been described. However, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Third Embodiment>

A first modification example of the third embodiment will be described with reference toFIG. 35orFIG. 36. Here, a body portion224-1of longitudinal shape has indicating portions29-1.

As shown inFIGS. 35 and 36, the body portion224-1is substantially elliptical in a plan view and has a longitudinal shape extending in one direction. Each indicating portion29-1is formed at the center of each outer edge of the body portion224-1in the long-side direction. The indicating portions29-1are formed by partially cutting the body portion224-1and are located symmetrically about the rotating center. With this configuration, when the rotating operation is performed, the rotating state of the board holding member220-1can be recognized more clearly by viewing the indicating portions29-1as well as the body portion224-1. Although the multifunctional board holding member220-1is shown inFIGS. 35 and 36, the monofunctional board holding member can have similar configuration.

A fourth embodiment of the present invention will be described with reference toFIGS. 37 to 40. In the fourth embodiment, an attachment portion325having modified configuration in a board holding member320is shown. Overlapping description of the same configuration, actions and effects as those in the first embodiment is omitted.

As shown inFIGS. 37 and 38, the holding portion325bof the attachment portion325in the board holding member320is constituted by a holding portion body30protruded from the shaft portion325atoward a body portion324and guiding protrusions31protruded from the holding portion body30toward the body portion324. The holding portion body30has almost same configuration as that of the holding portion25bin the first embodiment and detailed description thereof is omitted. The pair of guiding protrusions31is provided at both ends of the holding portion body30in the long-side direction, that is, both ends opposite to the shaft portion225a. The guiding protrusions31are hemispherical and their circumferential surfaces are spherical surfaces, which constitute guide surfaces31a. In the state where the attachment portion325is inserted into the attachment holes14eand the board holding member320is located at the non-holding position with respect to the chassis14, as shown inFIG. 39, the holding portion body30is protruded toward the back side of the chassis14and is arranged outside of the attachment holes14e, while the guiding protrusions31are arranged in the attachment holes14e. That is, at the non-holding position, in the holding portion325b, the holding portion body30forms an outer part O and the guiding protrusions31form inner parts I.

Then, when the board holding member320is rotated from the non-holding position, the edge of the attachment hole14eis in slide contact with the guiding protrusions31entered into the attachment hole14e. Then, the holding portion body30is guided by the guide surfaces31aof the guiding protrusions31to be elastically deformed using the shaft portion325aas a fulcrum. Accordingly, the guiding protrusions31are displaced toward the outside of the attachment hole14e. When the board holding member320reaches the holding position, as shown inFIG. 40, the guiding protrusions31are arranged outside of the attachment hole14eand contact with the back side surface of the chassis14, resulting that the LED board18and the chassis14are elastically sandwiched between the guiding protrusions31and the body portion324. At this time, a part of the body portion324between a contact portion326and the shaft portion325ais also elastically deformed. As a result, in the board holding member320, both the body portion324and the holding portion body30are elastically deformed, thereby being held at the holding position to prevent careless rotational displacement. Although the multifunctional board holding member320is shown inFIGS. 37 to 40, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, the holding portion325bhas the inner parts I arranged in the attachment hole14eand the outer part O arranged outside of the attachment hole14ein the state where the board holding member320is located at the non-holding position, and the inner parts I each have the guide surface31athat can be in slide contact with the edge of the attachment hole14ewith rotation of the board holding member320located at the non-holding position, thereby elastically deforming the holding portion325bwhile displacing the inner parts I toward the outside of the attachment hole14e. With this configuration, when the board holding member320is located at the non-holding position, the guide surface31ais in slide contact with the edge of the attachment hole14e, resulting that the inner part of the holding portion325bis displaced out of the attachment hole14eand elastically deformed. At the holding position, since the chassis14is elastically sandwiched between the body portion324and the elastically deformed holding portion325b, it can be prevented that the board holding member320is carelessly moved from the holding position to the non-holding position due to vibration or the like. Thereby, careless detaching of the board holding member320can be prevented.

The holding portion325bis constituted by the holding portion body30protruded from the shaft portion325ain substantially parallel with the body portion324and the guiding protrusions31that are protruded from the holding portion body30toward the body portion324and have the guide surfaces31a. The holding portion body30has the outer part O and the guiding protrusions31each include the inner part I. With this configuration, at the non-holding position, the guiding protrusions31are arranged in the attachment hole14e. When the board holding member20is rotated therefrom, the guide surface31aof the guiding protrusions31are in slide contact with the edge of the attachment hole14e, resulting that the guiding protrusions31are displaced out of the attachment hole14eand elastically deformed and the holding portion body30is elastically deformed. Thereby, the chassis14can be elastically sandwiched at the holding position.

The guiding protrusions31are arranged at ends on the side opposite to the shaft portion325aof the holding portion body30. With this configuration, since the distance between the shaft portion325aand the guiding protrusions31in the holding portion body30can be ensured to the maximum, it is easy to elastically deform the holding portion body30, thereby reducing a force necessary for rotating the board holding member320and improving the workability.

A fifth embodiment of the present invention will be described with reference toFIGS. 41 to 43. In the fifth embodiment, an attachment portion425having modified configuration in a board holding member420is shown. Overlapping description of the same configuration, actions and effects as those in the first embodiment is omitted.

As shown inFIG. 41, a holding portion425bof the attachment portion425in the board holding member420has a substantially rhombic cross section taken along its long-side direction. Describing in detail, the holding portion425bis tapered such that its thickness becomes smaller as the holding portion425bis away from the shaft portion325ain the long-side direction (as the holding portion425bmoves from the shaft portion425ato a protruding front end). Both a front side surface and a back side surface of the holding portion425bare tapered as a whole, and the front side surface as a surface facing a body portion424constitutes a guide surface32. The guide surface32is inclined such that an interval between the guide surface32and the body portion424becomes smaller as the guide surface32gets closer to the shaft portion425a. In the state where the attachment portion425is inserted into the attachment hole14eand the board holding member420is located at the non-holding position with respect to the chassis14, as shown inFIG. 42, most of the holding portion425bon the back side including the both ends in the long-side direction constitutes the outer part O that is protruded toward the back side of the chassis14and is arranged outside of the attachment hole14e, and a remainder of the holding portion425bon the front side constitutes the inner part I arranged in the attachment hole14e. Here, since the guide surface32is formed on the entire front side surface of the holding portion425b, that is, on both the outer part O and the inner part I. Accordingly, at the non-holding position, the guide surface32of the holding portion425bis arranged on both the inner and outer sides of the attachment hole14e.

When the board holding member420is rotated from the non-holding position, the edge of the attachment hole14eis in slide contact with the guide surface32of the inner part I of the holding portion425b. Then, by being guided by the guide surface32, the inner part I of the holding portion425bis displaced out of the attachment holes14e, and apart between the contact portion426and the shaft portion425ain the body portion424is elastically deformed. When the board holding member420reaches the holding position, as shown inFIG. 43, the entire holding portion425bis arranged outside of the attachment hole14eand comes in contact with the back side surface of the chassis14, resulting that the LED board18and the chassis14are elastically sandwiched between the holding portion425band the elastically deformed body portion424. Since the body portion424of the board holding member420is elastically deformed to be elastically held at the holding position in this manner, careless rotational displacement is prevented. Although the multifunctional board holding member420is shown inFIGS. 41 to 43, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, the attachment portion425includes the shaft portion425athat is protruded from the body portion424toward the chassis14and serves as the rotational axis of the board holding member420and the holding portion425bthat is protruded from the shaft portion425ain substantially parallel with the body portion424and is configured to sandwich the edge of the attachment hole14ebetween the holding portion425band the body portion424. The holding portion425bhas the inner part I arranged in the attachment hole14eand the outer part O arranged outside of the attachment hole14ein the state where the board holding member420is located at the non-holding position, and at least the inner part I has the guide surface32that is in slide contact with the edge of the attachment hole14ewith rotation of the board holding member420located at the non-holding position, thereby elastically deforming the body portion424while displacing the inner part I out of the attachment holes14e. With this configuration, when the board holding member420located at the non-holding position is rotated, the guide surface32is in slide contact with the edge of the attachment hole14e, resulting that the inner part I of the holding portion425bis displaced out of the attachment hole14e, and a part from the shaft portion425ato the contact portion426in the body portion424is elastically deformed. At the holding position, since the chassis14is elastically sandwiched between the holding portion425band the elastically deformed body portion424, it can be prevented that the board holding member420is carelessly moved from the holding position to the non-holding position due to vibration or the like. Thereby, careless detaching of the board holding member420can be prevented.

Both the holding portion425band the attachment hole14ehave a longitudinal shape, and the guide surface32is formed such that the interval between the surface of the holding portion425b, which faces the body portion424, and the body portion424becomes smaller as the guide surface32gets closer to the shaft portion425a. With this configuration, the interval between the guide surface32and the body portion424becomes smaller as the guide surface32gets closer to the shaft portion425a. Therefore, with rotation of the board holding member420from the non-holding position to the holding position, the body portion424is gradually elastically deformed and the site where the edge of the attachment hole14eis in slide contact with the guide surface32of the inner part I is gradually displaced toward the shaft portion425a, resulting that the inner part I is displaced out of the attachment holes14e. Thereby, the chassis14can be elastically sandwiched at the holding position.

The guide surface32is formed on the entire surface of the holding portion425b, which faces the body portion424. With this configuration, even when a dimensional error of the board holding member420or an assembling error to the chassis14occurs, the guiding function of the guide surface32can reliably be achieved.

The fifth embodiment of the present invention has been described and however, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Fifth Embodiment>

A first modification example of the fifth embodiment will be described with reference toFIGS. 44 to 46. Here, a holding portion425b-1having modified configuration is shown.

As shown inFIG. 44, a hollow portion33is formed in the holding portion425b-1. The hollow portion33passes through the holding portion425b-1in the short-side direction. The hollow portion33has a substantially rhombic cross section along the outer shape of the holding portion425b-1. Thus, the holding portion425b-1is configured to be elastically deformed to be recessed toward the hollow portion33. Accordingly, in rotating the board holding member420-1from the non-holding position shown inFIG. 45to the holding position shown inFIG. 46, when the guide surface32of the holding portion425b-1is in slide contact with the edge of the attachment hole14e, a body portion424-1is elastically deformed and the holding portion425b-1can also be elastically deformed. Thereby, an operating force necessary for the rotating operation can be reduced and the workability can be improved. Although the multifunctional board holding member420-1is shown inFIGS. 44 to 46, the monofunctional board holding member can include similar configuration.

As described above, in this modification example, the holding portion425b-1is formed so as to have the hollow portion33. With this configuration, the hollow portion33facilitates elastic deformation of the holding portion425b-1. Accordingly, the force necessary for rotating the board holding member420-1can be reduced, thereby improving the workability.

A sixth embodiment of the present invention will be described with reference toFIGS. 47 to 52. In the sixth embodiment, a rotation restricting structure restricting the rotational angle of the board holding member20is added. Overlapping description of the same configuration, actions and effects as those in the first embodiment is omitted. For convenience of explanation,FIGS. 47 and 50as plan views show the state where the LED board18and the reflection sheets22and23are removed from a chassis514.

As shown inFIGS. 47 to 49, chassis-side rotation restricting portions34protruded from an edge of an attachment hole514ein a bottom plate514aof the chassis514toward the back side (side opposite to the LED board18) are provided. Each chassis-side rotation restricting portion34is an individual component separated from the chassis514, and is fixedly attached (fixed) to a back surface of the bottom plate514athrough an adhesive layer or the like in an integral manner. The pair of chassis-side rotation restricting portions34is provided in a long-side circumferential part of the attachment hole514eand at positions shifted from the center (rotating center) in the long-side direction. Describing in detail, a pair of the chassis-side rotation restricting portions34has substantially rectangular shape extending in the long-side direction of the attachment hole514ein a plan view and are arranged to be symmetrical about the center of the attachment hole514eas a point of symmetry. The long-side direction and the short-side direction of the attachment hole514ecoincide with the long-side direction and the short-side direction of the chassis-side rotation restricting portions34. A side surface of the outer circumferential surface of the chassis-side rotation restricting portion34, which faces the attachment hole514e, is in flush with a long-side inner side surface of the attachment hole514e, and is configured to be engaged with a long-side side surface of the holding portion25bof the attachment portion25when the attachment portion25is inserted into the attachment hole514eat the non-holding position, which constitutes a first engaging surface34a. Thus, the rotating direction from the non-holding position can be restricted to only one direction (counterclockwise direction shown inFIG. 47). A side surface of the outer circumferential surface of the chassis-side rotation restricting portion34, which faces the center of the attachment hole514ein the long-side direction, is configured to be engaged with the long-side side surface of the holding portion25bof the attachment portion25when the board holding member20is rotated from the non-holding position by 90 degrees, which constitutes a second engaging surface34b. Thus, the angle by which the board holding member20can be rotated from the non-holding position can be restricted up to about 90 degrees.

In order to attach the board holding member20to the chassis514, the attachment portion25is inserted into the attachment hole514eto achieve the non-holding position. In rotating the board holding member20from the non-holding position, even if it is attempted to rotate the board holding member20in the clockwise direction shown inFIG. 47, the first engaging surface34aof each chassis-side rotation restricting portion34is engaged with the holding portion25bof the attachment portion25, thereby restricting rotation in the clockwise direction. When the board holding member20is rotated from the non-holding position in the counterclockwise direction shown inFIG. 47and the rotational angle reaches 90 degrees, as shown inFIGS. 50 to 52, the second engaging surface34bof each chassis-side rotation restricting portion34is engaged with the holding portion25bof the attachment portion25, thereby restricting further rotation in the counterclockwise direction. Since the operator only have to rotate the board holding member20until the rotating operation is restricted, the rotational angle of the board holding member20can reliably be set to about 90 degrees. Thereby, the rotational angle of the board holding member20from the non-holding position to the holding position can be made constant, thereby stably holding the board holding member20at the holding position. Although the multifunctional board holding member20is shown inFIGS. 47 to 52, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, among the board holding member20and the chassis514, the chassis514has the rotation restricting structure configured to the rotational angle of the board holding member20from the non-holding position. With this configuration, since the rotation restricting structure can restrict the rotational angle of the board holding member20from the non-holding position, the board holding member20can reliably be brought into the holding position.

The rotation restricting structure is constituted by the chassis-side rotation restricting portions34that are protruded from the chassis514toward the side opposite to the LED board18, and are engaged with the attachment portion25when the board holding member20is rotated from the non-holding position by a predetermined angle to restrict further rotation. With this configuration, when the board holding member20is rotated from the non-holding position by the predetermined angle, the chassis-side rotation restricting portions34are engaged with the attachment portion25, thereby restricting further rotation of the board holding member20. Thereby, the board holding member20can reliably be brought into the holding position.

Both the attachment portion25and the attachment hole514ehave rotationally symmetric shape of 2-fold symmetry in a plan view, and the rotation restricting structure can restrict the rotational angle of the board holding member20from the non-holding position to about 90 degrees. In the case where the attachment portion25and the attachment hole514ehave rotationally symmetric shape of 2-fold symmetry as described above, when the board holding member20is rotated from the non-holding position by 180 degrees, the board holding member20is located at the non-holding position again. Accordingly, the maximum rotational angle of the board holding member20from the non-holding position is 90 degrees. In this embodiment, since the rotation restricting structure restricts the rotational angle of the board holding member20from the non-holding position up to about 90 degrees, even when the board holding member20is rotationally displaced to some extent due to vibration or the like, the board holding member20is hard to reach the non-holding position and therefore, careless detaching of the board holding member20can be prevented.

The sixth embodiment of the present invention has been described and however, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Sixth Embodiment>

A first modification example of the sixth embodiment will be described with reference toFIG. 53orFIG. 54. Here, chassis-side rotation restricting portions34-1having modified configuration are shown.

As shown inFIG. 53, each chassis-side rotation restricting portion34-1is substantially rectangular in a plan view, and its long-side direction aligns with the short-side direction of the attachment hole514e. The chassis-side rotation restricting portion34-1is arranged adjacent to the center of the attachment hole514ein the long-side direction in the circumference of the attachment hole514e. Accordingly, as shown inFIG. 54, the long-side direction of the chassis-side rotation restricting portion34-1aligns with the long-side direction of the attachment portion25when the board holding member20is rotated from the non-holding position by 90 degrees to achieve the holding position, and a long-side side surface of the chassis-side rotation restricting portion34-1constitutes a second side surface34b-1engaged with the side surface of the holding portion25bof the attachment portion25. An end of the chassis-side rotation restricting portion34-1in the long-side direction is substantially in flush with an end of the holding portion25bof the attachment portion25located at the holding position in the long-side direction. As described above, in this modification example, since the bottom end to the protruding end of the holding portion25bof the attachment portion25is engaged with the second side surface34b-1of the chassis-side rotation restricting portion34-1and the engaging range is larger than that of the sixth embodiment, the rotation restricting function can be achieved more reliably.

A seventh embodiment of the present invention will be described with reference toFIGS. 55 to 60. In the seventh embodiment, the rotation restricting structure in the sixth embodiment is modified. Overlapping description of the same configuration, actions and effects as those in the sixth embodiment is omitted. For convenience of explanation,FIGS. 55 and 58as plan views show the state where the LED board18and the reflection sheets22and23are removed from a chassis614.

As shown inFIGS. 55 to 57, holding member-side rotation restricting portions35are provided in a region of a board holding member620, which are arranged in an attachment hole614eat both the holding position and the non-holding position. The holding member-side rotation restricting portions35communicate with both of an shaft portion625aand a holding portion625bof an attachment portion625and specifically, are coupled to a protruding front end of the shaft portion625afrom a body portion624and a protruding bottom end of the holding portion625bfrom the shaft portion625a. The pair of holding member rotation restricting portions35is arranged across the shaft portion625a, that is, are symmetrically arranged at positions shifted from the rotating center. Each holding member rotation restricting portion35is substantially block-like and has the almost same width as the short-side dimension of the holding portion625b(diameter of the shaft portion625a). Since the holding member rotation restricting portions35are arranged closer to the front side than the holding portion625b, in the state where the attachment portion625is inserted into the attachment hole614e(the holding position and the non-holding position), the holding member rotation restricting portions35together with the shaft portion625aenter into the attachment hole614eat all times. The holding portion625bis protruded from the chassis614toward the back side.

The attachment hole614eis larger than the attachment portion625in a plan view. Describing in detail, the attachment hole614eis constituted by an elliptical attachment hole body614e1of the almost same as the planar shape of the attachment portion625and a pair of extending portions614e2formed by cutting edges on both long sides of the attachment hole body614e1, and is symmetrical about the center of the attachment hole body614e1as a point of symmetry. The extending portions614e2are formed so as to include a center part of the attachment hole body614e1in the long-side direction and reach ends of the attachment hole body614e1in the long-side direction, and are larger than the rotational track of the holding member rotation restricting portion35at least when the board holding member620is rotated from the non-holding position by 90 degrees. When the board holding member620is rotated from the non-holding position by 90 degrees, side surfaces of the extending portions614e2along the Y-axis direction in the inner circumferential surface is configured to be engaged with the side surfaces of the holding member rotation restricting portions35, which constitute engaging surfaces614e3. Thereby, the angle by which the board holding member620can be rotated from the non-holding position can be restricted up to about 90 degrees. In the state where the attachment portion625is inserted into the attachment hole614eto attain the non-holding position, the part that is a center part of the inner circumferential surface of the attachment hole body614e1in the long-side direction and is adjacent to the extending portion614e2is opposed to the side surface of each holding member rotation restricting portion35, thereby restricting the rotating direction from the non-holding position to only one direction (counterclockwise direction shown inFIG. 55). The through hole18bin the LED board18and the communicating holes22cand23cin the reflection sheets22and23have the same planar shape as those in the first embodiment, but they may have the same planar shape as the attachment hole614according to this embodiment.

When the board holding member620is rotated from the non-holding position in the counterclockwise direction shown inFIG. 55and the rotational angle reaches 90 degrees, as shown inFIGS. 58 to 60, the holding member-side rotation restricting portions35are engaged with the engaging surfaces614e3of the extending portions614e2of the attachment hole614e, thereby restricting further rotation in the counterclockwise direction. Since the operator only have to rotate the board holding member620until the rotating operation is restricted, the rotational angle of the board holding member620can reliably be set to about 90 degrees. Thereby, the rotational angle of the board holding member620from the non-holding position to the holding position can be made constant and therefore, the board holding member620can be stably held at the holding position. Although the multifunctional board holding member620is shown inFIGS. 55 to 60, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, the rotation restricting structure is provided in the board holding member620and is constituted by the holding member-side rotation restricting portions35arranged in the attachment hole614e. The attachment hole614e, on the other hand, is constituted by the attachment hole body614e1along the outer shape of the attachment portion625in a plan view and the extending portions614e2that extend from the attachment hole body614e1and allow rotational displacement of the holding member-side rotation restricting portions35. When the board holding member620is rotated from the non-holding position by the predetermined angle, the holding member-side rotation restricting portions35are engaged with the engaging surfaces614e3as the inner surfaces of the extending portions614e2, thereby restricting further rotation. With this configuration, when the board holding member620is rotated from the non-holding position, the holding member-side rotation restricting portions35allow rotational displacement in the extending portions614e2of the attachment hole614e, and when the rotational angle reaches the predetermined rotational angle, the holding member-side rotation restricting portions35are engaged with the engaging surfaces614e3as the inner surfaces of the extending portions614e2, thereby restricting further rotation of the board holding member620. As a result, the board holding member620can reliably be brought into the holding position. As compared to the case where the chassis-side rotation restricting portions34as separated units are installed in the chassis514as in the sixth embodiment, in this embodiment, costs can be reduced by changing the shape of the board holding member620and the attachment hole614e.

The attachment portion625includes the shaft portion625athat is protruded from the body portion624toward the chassis614and serves as the rotational axis of the board holding member620and the holding portion625bthat is protruded from the shaft portion625ain substantially parallel with the body portion624and is configured to sandwich the edge of the attachment hole614ebetween the holding portion625band the body portion624, and the holding member-side rotation restricting portions35communicate with both the shaft portion625aand the holding portion625b. With this configuration, the holding member-side rotation restricting portions35that communicate with both the shaft portion625aand the holding portion625bcan reinforce the attachment portion625.

The seventh embodiment of the present invention has been described and however, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Seventh Embodiment>

A first modification example of the seventh embodiment will be described with reference toFIGS. 61 to 63. Here, the installed number of holding member-side rotation restricting portions35-1is changed.

As shown inFIGS. 61 and 62, in this modification example, only one holding member-side rotation restricting portion35-1is provided at an attachment portion625-1at a position shifted from the rotating center. One extending portions614e2-1and one engaging surface614e3-1aare provided in the attachment hole614e-1. In inserting the attachment portion625-1into the attachment hole614e-1, the holding member-side rotation restricting portion35-1is oriented so as to enter on the side of the extending portions614e2-1of the attachment hole614e-1. The board holding member620-1is located at the non-holding position and subsequently, is rotated in the counterclockwise direction shown inFIG. 62. When the rotational angle reaches 90 degrees, as shown inFIG. 63, the holding member-side rotation restricting portion35-1is engaged with the engaging surface614e3-1of the extending portions614e2-1, thereby restricting further rotation. Although the multifunctional board holding member620-1is shown inFIGS. 61 to 63, the monofunctional board holding member can have similar configuration.

<Second Modification Example of Seventh Embodiment>

A second modification example of the seventh embodiment will be described with reference toFIGS. 64 to 66. Here, holding member-side rotation restricting portions35-2of modified shape are shown.

As shown inFIGS. 64 and 65, each holding member-side rotation restricting portion35-2in this modification example communicates with only the holding portion625b-2of the attachment portion625-2. Describing in detail, each holding member-side rotation restricting portion35-2is circular in a plan view, and its diameter is smaller than the short-side dimension of the holding portion625b-2. The pair of holding member-side rotation restricting portions35-2is arranged on a holding portion625b-2symmetrically about a bottom portion625a-2at positions separated from the bottom portion625a-2. Each holding member-side rotation restricting portion35-2is arranged at a position that is substantially in flush with each outer side surface of the holding portion625b-2on the side of the long side. When the board holding member is rotated from the non-holding position in the counterclockwise direction shown inFIG. 65and the rotational angle reaches 90 degrees, as shown inFIG. 66, the holding member-side rotation restricting portions35-2are engaged with the engaging surfaces614e3of the extending portions614e2, thereby restricting further rotation. Although the multifunctional board holding member620-2is shown inFIGS. 64 to 66, the monofunctional board holding member can have similar configuration.

An eighth embodiment of the present invention will be described with reference toFIGS. 67 to 72. In the eighth embodiment, the rotation restricting structure in the sixth embodiment is modified. Overlapping description of the same configuration, actions and effects as those in the sixth embodiment is omitted. For convenience of explanation,FIGS. 67 and 70as plan views show the state where the LED board18and the reflection sheets22and23are detached from the chassis714.

As shown inFIGS. 67 to 69, holding member-side engaging portions36are provided in an attachment portion725of a board holding member720. Describing in detail, the holding member-side engaging portions36are protruded from a front side surface of a holding portion725bof the attachment portion725toward the front side (body member724side) (protrusion). The pair of holding member-side engaging portions36is separated from a bottom portion725ain the holding portion725band is arranged so as to sandwich the shaft portion725a, that is, to be symmetrical about the rotating center. Each holding member-side engaging portion36is substantially circular in a plan view, has the diameter that is smaller than the short-side dimension of the holding portion725band is arranged at the center of the holding portion725bin the short-side direction. Each holding member-side engaging portion36is substantially hemispherical and has a spherical circumferential surface. Chassis-side engaging portions37with which the holding member-side engaging portions36is configured to be engaged are provided at positions away from an attachment hole714ein a bottom plate714aof a chassis714. Describing in detail, each chassis-side engaging portion37is shaped like a hole passing through the bottom plate714a(recess), and like a circle having a larger diameter than that of the holding member-side engaging portion36in a plan view. The pair of chassis-side engaging portions37is symmetrically arranged so as to sandwich the attachment hole714ein the short-side direction (Y-axis direction), and have the same center as that of the attachment hole714ein the X-axis direction. A line connecting the chassis-side engaging portions37to each other crosses the center of the attachment hole714e, aligns with the short-side direction of the attachment hole714eand is orthogonal to the long-side direction of the attachment hole714e.

When the board holding member720is attached to the chassis714, the attachment portion725is inserted into the attachment hole714eto achieve the non-holding position. The board holding member720is rotated from the non-holding position in the counterclockwise direction or the clockwise direction inFIG. 67. Then, each holding member-side engaging portion37is in slide contact with the back surface of the bottom plate14a, resulting that the holding portion725bis elastically deformed once using the shaft portion725aas a fulcrum. Then, when the rotational angle reaches 90 degrees, as shown inFIG. 70toFIG. 72, each holding member-side engaging portion37is fitted into each chassis-side engaging portion36, their counter circumferential surfaces are engaged with each other and the holding portion725belastically returns. In this manner, the board holding member720that is rotated from the non-holding position by 90 degrees and reaches the holding position is prevented from rotating in both the forward and backward directions and therefore, board holding member720can be stably held at the holding position. Although the multifunctional board holding member720is shown inFIGS. 67 to 72, the monofunctional board holding member can have similar configuration.

As described above, in this embodiment, the rotation restricting structure is provided in each of the chassis714and the attachment portion725. Each restricting structure includes the engaging portions (the holding member-side engaging portions36and the chassis-side engaging portions37) which are engaged with the protrusion fitted in the recess when the board holding member720is rotated from the non-holding position by the predetermined angle (90 degrees), thereby restricting rotation in the forward and backward directions. With this configuration, when the board holding member720is rotated from the non-holding position by the predetermined angle, the holding member-side engaging portions36and the chassis-side engaging portions37as the engaging portions provided in the chassis714and the attachment portion725are engaged with the protrusion fitted in the recess and thus, the board holding member720is prevented from rotating in both the forward and backward directions. Thereby, the board holding member720can reliably be brought into the holding position and the holding position can be stably maintained.

The eighth embodiment of the present invention has been described and however, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Eighth Embodiment>

A first modification example of the eighth embodiment will be described with reference toFIGS. 73toFIG. 75. Here, the protrusion and the recess of the engaging portions are reversed.

As shown inFIGS. 73 and 74, each chassis-side engaging portion37-1is protruded from a back surface of a bottom plate714a-1of a chassis714-1toward the back side (protrusion). The chassis-side engaging portion37-1is formed by partially beating outward the bottom plate714a-1in an integral manner. The chassis-side engaging portion37-1may be an individual component separated from the chassis714-1and be fixedly attached to the chassis714-1through an adhesive layer or the like. The holding member-side engaging portion36-1is shaped like a hole passing through the holding portion725b-1in the Z-axis direction (concave), and like a circle having a larger diameter than that of the chassis-side engaging portion37-1in a plan view. When the board holding member720-1is rotated from the non-holding position by 90 degrees, as shown inFIG. 75, the chassis-side engaging portion37-1is fixed into the holding member-side engaging portion36-1and their opposed circumferential surfaces are engaged with each other, thereby holding the board holding member720-1at the holding position.

A ninth embodiment of the present invention will be described with reference toFIGS. 76 to 81. In the ninth embodiment, the rotation restricting structure in the seventh embodiment is modified. Overlapping description of the same configuration, actions and effects as those in the seventh embodiment is omitted. For convenience of explanation,FIGS. 76 and 79as plan views show the state where the LED board18and the reflection sheets22and23are removed from a chassis814.

An attachment portion825and a holding member-side rotation restricting portion835in a board holding member820have similar configuration to that in the seventh embodiment and thus, overlapping description thereof is omitted. As shown inFIG. 76, an attachment hole814eis constituted by an attachment hole body814e1having the almost same elliptical shape as the planar shape of the attachment portion825and a pair of extending portions814e2formed by partially cutting a part of edges of the attachment hole body814e1on the side of the long side. Each extending portion814e2is arranged at the center of the attachment hole body814e1in the long-side direction, is rectangular in a plan view and has shape corresponding to the outer shape of the holding member-side rotation restricting portion835. The holding member-side rotation restricting portion835is configured to be engaged with the extending portions814e2, and an inner circumferential surface (a pair of side surfaces along the Y-axis direction and a side surface along the X-axis direction) of each extending portion814e2constitutes an engaging surface814e3that can be engaged with an outer side surface of the holding member-side rotation restricting portion835(FIG. 79).

To attach a board holding member820to a chassis814, as shown inFIGS. 76 and 77, the attachment portion825is inserted into the attachment hole814eto achieve the non-holding position. As shown inFIG. 77, in the state where each contact portion826is in contact with the chassis reflection sheet22, when the supporting portion28is pressed downward (toward the chassis814), a body portion824is elastically deformed in the shape of a bow using each contact portion826as a fulcrum. Then, the center part of the body portion824, that is, the part where the attachment portion825is installed is displaced downward, and the attachment portion825and the holding member-side rotation restricting portion835are also displaced in the same direction. As shown inFIG. 78, the holding member-side rotation restricting portion835is protruded toward the back side of the chassis814and escapes from the attachment hole814e. After that, the board holding member820is rotated. At this time, by performing the rotating operation while applying a pressing force to a supporting portion828(while elastically deforming the body portion824), it can be prevented that the holding member-side rotation restricting portion835interferes with the inner circumferential surface of the attachment hole814e(engaging surface814e3), thereby blocking the rotating operation. The board holding member820may be rotated in both the forward and backward directions.

When the rotational angle of the board holding member820from the non-holding position reaches 90 degrees, as shown inFIGS. 79 and 80, each holding member-side rotation restricting portion835overlaps (aligns) with each extending portion814e2of the attachment hole814ein a plan view. In this state, when pressing the supporting portion828downward is stopped (the pressing force is released), the body portion824elastically returns, and each holding member-side rotation restricting portion835is fitted in each extending portion814e2. Then, as shown inFIGS. 79 and 81, since the outer side surfaces of the holding member-side rotation restricting portions835are engaged with the engaging surface814e3of the extending portions814e2, it is prevented that the board holding member820is rotationally displaced from the holding position in both the forward and backward directions. Thereby, the board holding member820can be stably held at the holding position obtained by rotation from the non-holding position by 90 degrees. When the rotational angle from the non-holding position is less than 90 degrees or more than 90 degrees, the holding member-side rotation restricting portions835do not match the extending portions814e2, and the body portion824remains to be elastically deformed, which represents that the rotational angle is too little or too much. In this case, the rotating operation is performed until the body portion824elastically returns. Although the multifunctional board holding member820is shown inFIGS. 76 to 81, the monofunctional board holding member can have similar configuration.

The ninth embodiment of the present invention has been described and however, the present invention is not limited to the embodiment and may include following modification examples. In each of the following modification examples, the same members as those in the above-mentioned embodiment are given the same reference numerals and illustration and description thereof may be omitted.

<First Modification Example of Ninth Embodiment>

A first modification example of the ninth embodiment will be described with reference toFIGS. 82 to 87. Here, an attachment hole814e-1of modified shape is shown.

As shown inFIG. 82, an attachment hole814e-1is substantially rectangular in a plan view, its long-side dimension is the almost same as the long-side dimension of the attachment portion825and its short-side dimension is larger than the short-side dimension of the attachment portion825. Describing in detail, the short-side dimension of the attachment hole814e-1substantially aligns with the length of the attachment portion825in both the holding member-side rotation restricting portions835in the long-side direction (the X-axis direction inFIG. 82and the Y-axis direction inFIG. 85). A surface along the long-side direction (X-axis direction) in the inner circumferential surface of the attachment hole814e-1constitutes an engaging surface814e3-1that can be engaged with the outer side surface of the attachment portion825of each holding member-side rotation restricting portion835in the short-side direction.

As shown inFIGS. 82 and 83, the attachment portion825is inserted into the attachment hole814e-1to achieve the non-holding position. Then, in the state where each contact portion826is in contact with the chassis reflection sheet22, when the supporting portion28is further pressed downward (toward the chassis814-1), the body portion824is elastically deformed in the shape of a bow using each contact portion826as a fulcrum. As shown inFIG. 84, the holding member-side rotation restricting portion835is protruded toward the back side of the chassis814-1and escapes from the attachment hole814e-1and then, the board holding member820is rotated. When the rotational angle of the board holding member820from the non-holding position reaches 90 degrees, as shown inFIGS. 85 and 86, the outer side surface of each holding member-side rotation restricting portion835along the short-side direction of the attachment portion825is parallel to the X-axis direction, that is, the long-side direction of the attachment hole814e-1. In this state, when pressing the supporting portion828downward is stopped (the pressing force is released), the body portion824elastically returns, and each holding member-side rotation restricting portion835enters into the attachment hole814e-1. Then, as shown inFIGS. 85 and 87, since the outer side surface of each holding member-side rotation restricting portion835along the short-side direction of the attachment portion825is engaged with the engaging surface814e3-1of the attachment hole814e-1, it is prevented that the board holding member820is rotationally displaced from the holding position in both the forward and backward directions. Thereby, the board holding member820can be stably held at the holding position rotated from the non-holding position by 90 degrees. Although the multifunctional board holding member820is shown inFIGS. 82 to 87, the monofunctional board holding member can have similar configuration.

The present invention is not limited to the embodiments described in the above description and figures, and for example, following embodiments fall within the technical scope of the present invention.

(1) In embodiments other than each of the above-mentioned embodiments, the planar shape of the attachment portion and the attachment hole maybe appropriately changed. Describing in detail, the planar shape of the attachment portion and the attachment hole only needs to be noncircular, and is preferably longitudinal shape such as rectangle, rhomboid and ellipse. Alternatively, the planar shape of the attachment portion and the attachment hole may be regular polygon (including square, regular triangle, regular hexagon and the like). The planar shape of the attachment portion and the attachment hole may be shaped like a substantially perfect circle and then, changed to be a non-perfect circle by forming a protrusion on the outer edge or a recess in the outer edge. The shape of the through hole and the communicating hole may be changed so as to correspond to the shape of the attachment hole.

(2) In embodiments other than each of the above-mentioned embodiments, the planar shape of the body portion may be appropriately changed. Describing in detail, the planar shape of the body portion may be, for example, rectangle, rhomboid, ellipse, regular polygon (including square, regular triangle, regular hexagon and the like). When the planar shape of the body portion is a polygon, the body portion can easily be rotated and therefore, the gripping portion or the supporting portion may be omitted.

(3) In embodiments other than each of the above-mentioned embodiments, the planar shape of the gripping portion and the supporting portion may be appropriately changed. The planar shape of the gripping portion may be, for example, rhomboid, ellipse, regular polygon (including square, regular triangle, regular hexagon and the like). The planar shape of the supporting portion may be, for example, rhomboid, ellipse, regular polygon (including square, regular triangle, regular hexagon and the like).

(4) Although the diameter of the shaft portion of the attachment portion is the almost same as the short-side dimension of the holding portion in each of the above-mentioned embodiments, it is possible to set the diameter of the shaft portion to be smaller than the short-side dimension of the holding portion or to be larger than the short-side dimension of the holding portion. When the diameter of the shaft portion is set to be larger than the short-side dimension of the holding portion, since the shaft portion is partially projected from the outer edge of the holding portion, the planar shape of the attachment hole needs to reflect the projected part of the shaft portion. With this configuration, the projected part of the shaft portion contacts with the edge of the attachment hole, thereby positioning the board holding member with respect to the chassis.

(5) Although the long-side direction of the through hole formed in the LED board aligns with the extending direction of the wiring pattern in each of the above-mentioned embodiments, for example, configuration in which the short-side direction of the through hole aligns with the extending direction of the wiring pattern also falls within the scope of the present invention.

(6) Although the holding portion of the attachment portion is symmetrical about the shaft portion in each of the above-mentioned embodiments, the asymmetrically shaped holding portion also falls within the scope of the present invention.

(7) Although the board holding member is rotated from the non-holding position to the holding position by about 90 degrees in each of the above-mentioned embodiments, the rotational angle between these positions maybe any angle other than 90 degrees except for an integral multiple of 180 degrees.

(8) Although the shaft portion (rotating center) of the attachment portion is concentric with the body portion in each of the above-mentioned embodiments, the shaft portion (rotating center) located so as not to be concentric with the body portion also falls within the scope of the present invention.

(9) Although the gripping portion and the supporting portion are concentric with the shaft portion (rotating center) of the attachment portion in each of the above-mentioned embodiments, the gripping portion or the supporting portion that is located so as not to concentric with the shaft portion (rotating center) also falls within the scope of the present invention.

(10) Although the long-side direction of the gripping portion aligns with the long-side direction of the attachment portion in each of the above-mentioned embodiments, configuration in which the long-side direction of the gripping portion crosses (including, orthogonal to) the long-side direction of the attachment portion also falls within the scope of the present invention.

(11) Although in the first embodiment, the line connecting the diagonally located contact portions to each other aligns with the long-side direction or the short-side direction of the attachment portion, the line that crosses the long-side direction or the short-side direction of the attachment portion also falls within the scope of the present invention.

(12) Although the long-side direction of the body portion is orthogonal to the long-side direction of the attachment portion in the second embodiment, arrangement in which the long-side direction of the body portion aligns with the long-side direction of the attachment portion also falls within the scope of the present invention.

(13) Although the line connecting a pair of the indicating portions to each other aligns with the long-side direction of the attachment portion in the third embodiment, the line may cross (be orthogonal to) the long-side direction of the attachment portion.

(14) Although the indicating portions are formed by partially cutting the body portion in the third embodiment, the indicating portions may be formed by partially protruding the body portion. Alternatively, the indicating portions as colored portions or marks in the body portion also fall within the scope of the present invention.

(15) Although the indicating portions are arranged in the outer edge of the body portion in the third embodiment, the position of the indicating portions may be appropriately changed to any position other than the outer edge except for the center of the body portion. The number of indicating portions may be changed from two.

(16) Although both the body portion and the holding portion of the attachment portion are elastically deformed in the fourth embodiment, only the body portion may be elastically deformed or only the holding portion may be elastically deformed by appropriately changing rigidity (strength) of the body portion and the holding portion.

(17) Although almost the entirety of the guiding protrusions constitutes the inner part in the fourth embodiment, configuration in which only a part of the guiding protrusions constitutes the inner part and the remainder constitutes the outer part also falls within the scope of the present invention.

(18) Although the guide surface of each guiding protrusion is a spherical surface in the fourth embodiment, the guide surface may be a tapered surface or a curved surface other than the spherical surface. The number of and arrangement of the guiding protrusions of the holding portion body may be appropriately changed.

(19) Although the guide surface is the tapered surface in the fifth embodiment, the guide surface maybe a spherical surface or a curved surface other than the spherical surface.

(20) Although the board holding member has only one attachment portion in each of the above-mentioned embodiments, the board holding member having the plurality of attachment portions also falls within the scope of the present invention. In this case, when the number of attachment portions is an even number, the shaft portion of the attachment portion does not coincide with the rotational axis of the board holding member.

(21) Although the body portion of the board holding member is arranged at the midpoint between the adjacent LEDs in the X-axis direction in each of the above-mentioned embodiments, the body portion arranged closer to either of the adjacent LEDs also falls within the scope of the present invention. Similarly, in addition to the body portion arranged at the center of the LED board in the short-side direction, the body portion displaced from the center of the LED board in the short-side direction also falls within the scope of the present invention.

(22) Although the through hole is formed in the LED board in each of the above-mentioned embodiments, by arranging the attachment portion at the non-holding position so as not to overlap with the LED board in a plan view, the through hole may be omitted from the LED board.

(23) Although the two types of large and small attachment holes in the chassis and large and small communicating holes in each reflection sheet are provided in each of the above-mentioned embodiments, dimension of the attachment hole and the communicating hole may have one type or three or more types.

(24) Although the monofunctional board holding member and the multifunctional board holding member are simultaneously used in each of the above-mentioned embodiments, the configuration using only the monofunctional board holding member or only the multifunctional board holding member also falls within the scope of the present invention. The ratio of the monofunctional board holding member to the multifunctional board holding member, which is simultaneously used, may be appropriately changed.

(25) To distinguish the two types of board holding members from each other, in each of the above-mentioned embodiments, the board holding members are classified into “monofunctional” and “multifunctional”. However, the term “monofunctional” does not mean that the board holding member has no function other than the function of holding the LED board. The terms “monofunctional” and “multifunctional” are named based on presence/absence of the supporting function for the optical member for convenience of explanation, and do not preclude the possibility that the “monofunctional” board holding member has a function accompanying the holding function (for example, positioning function with respect to the LED board) and other additive functions.

(26) In embodiments other than each of the above-mentioned embodiments, the specific shape, arrangement and number of contact portions installed may be appropriately changed. Specifically, the contact portion shaped like a cylinder, a rectangular column, a cone, a pyramid or the like, and the contact portion having an angular (triangular) or elliptic cross section also fall within the scope of the present invention. The contact portion may be arranged in the body portion at a position other than the outer edge. The three or less or five or more contact portion may be installed in the body portion.

(27) Although the part of the body portion between the shaft portion of the attachment portion and the contact portion has elasticity in each of the above-mentioned embodiments, the body portion does not necessarily have elasticity, and the body portion that is hardly elastically deformed or is not elastically deformed at all also falls within the scope of the present invention. Even in this case, since the positions where the pressing force is exerted to each reflection sheet from the front side and the back side are shifted from each other in a plan view, stress concentration on each reflection sheet can be preferably mitigated and therefore, the degree of freedom in expansion and contraction is improved.

(28) Contrary to the (27), in assigning elasticity to the part of the body portion between the shaft portion of the attachment portion and the contact portion, for example, by designing the body portion so as to be easily flexed and thus, increasing the protruding dimension of the contact portion from the body portion, even when no dimensional error occurs, the body portion can be elastically deformed.

(29) Although the diffuser lens that diffuses light from the LED is used in each of the above-mentioned embodiments, an optical lens other than the diffuser lens (for example, a collective lens) falls within the scope of the present invention. Configuration without the diffuser lens also falls within the scope of the present invention. In this case, with omission of the diffuser lens, the board reflection sheet may also be omitted.

(30) Although the metal chassis is used in each of the above-mentioned embodiments, the chassis may be made of synthetic reason.

(31) Although the color of the surface of the board supporting member is white in each of the above-mentioned embodiments, the color of the surface of the board supporting member may be creamy white or silver. Color of the surface may be set by applying paint of a desired color on the surface of the board supporting member.

(32) Although the five-mounted type, the six-mounted type and the eight-mounted type of LED boards are combined as appropriate in each of the above-mentioned embodiments, an LED board that mounts the number of LEDs other than five, six and eight LEDs falls within the scope of the present invention.

(33) Although the LED that includes the LED chip that emits only blue light and emits white light by means of the phosphor is used in each of the above-mentioned embodiments, an LED that includes the LED chip that emits only ultraviolet light and emits white light by means of the phosphor falls within the scope of the present invention.

(34) Although the LED that includes the LED chip that emits only blue light and emits white light by means of the phosphor is used in each of the above-mentioned embodiments, an LED that has three types of LED chips that emit R, G, B, respectively, falls within the scope of the present invention. Moreover, an LED that has three types of LED chips that emit C (cyan), M (magenta), and Y (yellow), respectively, also falls within the scope of the present invention.

(35) Although the LED that emits white light is used in each of the above-mentioned embodiments, an LED that emits red light, an LED that emits blue light and an LED that emits green light may be combined as appropriate.

(36) Although the LED is used as the light source in each of the above-mentioned embodiments, a point light source other than the LED also falls within the scope of the present invention.

(37) Also in embodiments other than each of the above-mentioned embodiments, screen size and aspect ratio of the liquid crystal display device may be changed as appropriate.

(38) Although the liquid crystal panel and the chassis are arranged in the longitudinally mounted state so that the short-side direction matches the vertical direction in each of the above-mentioned embodiments, the configuration in which the liquid crystal panel and the chassis are arranged in the longitudinally mounted state so that the long-side direction matches the vertical direction also falls within the scope of the present invention.

(39) Although the TFT is used as the switching component of the liquid crystal display device in each of the above-mentioned embodiments, the present invention can also be applied to a liquid crystal display device using a switching component (for example, a thin film diode (TFD)) other than TFT and the monochrome liquid crystal display device other than the color liquid crystal display device.

(40) Although the liquid crystal display device using the liquid crystal panel as the display panel is illustrated in each of the above-mentioned embodiments, the present invention can be applied to a display device using the other type of display panel.

(41) Although the television receiver having a tuner is illustrated in each of the above-mentioned embodiments, the present invention can be applied to a display device having no tuner.

(42) Although a pair of the chassis-side rotation restricting portions is provided in the sixth embodiment and its modification example, only one chassis-side rotation restricting portion or three or more chassis-side rotation restricting portions also fall within the scope of the present invention.

(43) Although the chassis-side rotation restricting portion is in flush with the inner circumferential surface of the attachment hole and the rotating direction of the board holding member from the non-holding position is restricted to one direction in the sixth embodiment and its modification example, the chassis-side rotation restricting portion located so as not be in flush with the inner circumferential surface of the attachment hole (the chassis-side rotation restricting portion located away from the attachment hole) also falls within the scope of the present invention.

(44) Although the holding member-side rotation restricting portion communicates with the holding portion of the attachment portion in the seventh embodiment and its modification example, the holding member-side rotation restricting portion that communicates with only the shaft portion of the attachment portion also falls within the scope of the present invention.

(45) Although the holding member-side rotation restricting portion is provided in the attachment portion in the seventh embodiment and its modification example, the holding member-side rotation restricting portion may be provided in the body portion. In this case, the holding member-side rotation restricting portion protruded from the body portion toward the back side may enter into the attachment hole at the non-holding position and the holding position.

(46) Although a pair of the holding member-side engaging portions and a pair of the chassis-side engaging portions are provided in the eighth embodiment and its modification example, configuration in which one holding member-side engaging portion and one chassis-side engaging portion are provided, or three or more holding member-side engaging portions and three or more chassis-side engaging portions are provided also falls within the scope of the present invention. The number of holding member-side engaging portions does not need to be equal to the number of chassis-side engaging portions installed, and the number of holding member-side engaging portions and chassis-side engaging portions on the protrusion side may be smaller than that of holding member-side engaging portions and chassis-side engaging portions on the hole (recess) side.

(47) Although the chassis-side engaging portion passes through the chassis in the eighth embodiment and the holding member-side engaging portion passes through the holding portion in its modification example, the concave chassis-side engaging portion formed by being partially dented without passing through the chassis, or the concave holding member-side engaging portion formed by being partially dented without passing through the holding portion also falls within the scope of the present invention. In forming such concave holding member-side engaging portion, the holding member-side engaging portion may be formed in the shape of a line extending in the short-side direction of the holding portion.

(48) Although the rotation restricting structure restricts the rotational angle of the board holding member from the non-holding position to about 90 degrees in the sixth to the ninth embodiments and their modification examples, for example, by setting arrangement and shape of the rotation restricting structure, the rotational angle from the non-holding position may be restricted to any angle other than 90 degrees, and the specific value of the rotational angle may be appropriately changed.