Illumination apparatus, display apparatus, and electronic device

In an illumination apparatus, a plurality of light-emitting elements are mounted to one surface (a first surface) of a light source substrate. The light source substrate is anchored to a substrate support portion using a screw that is tightened down into the substrate support portion from the opposite side as the light source substrate. Meanwhile, the light source substrate includes a metallic plate that configures another surface (a second surface) and a flexible wiring board that is affixed to the metallic plate on the side of the one surface (the first surface), and a through-hole that passes through the metallic plate is formed, as the hole for tightening down the screw, in the location of the light source substrate in which the screw is tightened.

BACKGROUND

1. Technical Field

The present invention relates to illumination apparatuses provided with light guiding plates and light-emitting elements, display apparatuses provided with such illumination apparatuses, and electronic devices provided with such display apparatuses.

2. Related Art

Of the various types of display apparatuses, liquid-crystal apparatuses include an illumination apparatus referred to as a “light guiding plate apparatus” and a transmissive or partially-transmissive display panel (liquid-crystal panel) disposed on top of the illumination apparatus in an overlapping manner on the side of the light-emitting surface thereof; in the illumination apparatus, a plurality of light-emitting elements are provided along the side-end surfaces of the light guiding plate that function as light-entry portions.

As shown inFIG. 9, in an illumination apparatus configured in this manner, a configuration is often employed in which a plurality of light-emitting elements1089are mounted on a light source substrate1088on one surface1881that opposes a side-end surface of a light guiding plate1080, and the light source substrate1088is anchored to a substrate support plate portion1062using screws. At this time, when the screws are tightened from the side of the one surface1881of the light source substrate1088, areas where the light diffusion characteristics are uneven arise in the one surface1881of the light source substrate1088due to differences in the surface states on both sides of the locations where the screws are disposed, in the lengthwise direction of the light source substrate1088. As a result, unevenness in the brightness of the illumination light emitted from the light guiding plate occurs, resulting in a problem that the image quality is reduced.

Meanwhile, a structure in which through-holes1625are formed in the substrate support plate portion1062and the light source substrate1088is anchored to the substrate support plate portion1062by tightening screws1086into the substrate support plate portion1062from the opposite side as the light source substrate1088has been proposed (see JP-A-2011-40388, FIG. 13 and so on, and JP-A-2009-3081, FIGS. 2, 7, 10, and so on).

To realize this configuration, closed-ended holes1885that span to a position partway through the thickness direction of the light source substrate1088are formed from another surface1882of the light source substrate1088, and the screws1086are tightened into the holes1885.

However, as shown inFIG. 9, it is necessary to properly manage the depth of the holes1885in order to form those closed-ended holes1885that span to a position partway through the thickness direction of the light source substrate1088from the other surface1882of the light source substrate1088, and thus a great amount of effort is required to form the holes1885. In other words, as described above, if the holes1885are passed through the light source substrate1088, the surfaces of the screws1086that pass through and are exposed on the side of the one surface1881of the light source substrate1088will cause differences from other surfaces in the light diffusion state, reflection state, and so on; this leads to areas of optical unevenness, which causes the uniformity of the illumination to be lost. Alternatively, there may be the risk that wires formed on the one surface1881of the light source substrate1088will become disconnected. On the other hand, if the holes1885are too shallow, the light source substrate1088will be pressurized by the screws1086when the screws1086are tightened down, resulting in the light source substrate1088deforming and the optical axes of the light-emitting elements1089tilting.

SUMMARY

It is an advantage of some aspects of the invention to provide an illumination apparatus in which screw-holes can be formed at an appropriate depth in a light source substrate on which a light-emitting element is mounted in order to anchor the light source substrate to a substrate support plate portion using screws, a display apparatus provided with such an illumination apparatus, and an electronic device provided with such a display apparatus.

An illumination apparatus according to an aspect of the invention includes: a light guiding plate; a plurality of light-emitting elements disposed along a side-end surface of the light guiding plate that serves as a light-entry portion, each of the plurality of light-emitting elements has a light-emitting surface facing toward the side-end surface; a light source substrate that extends along a direction which the side-end surface extends, a first surface of the light source substrate on which the plurality of light-emitting elements are mounted, and a second surface which is another surface of the light source substrate that opposes the first surface; a substrate support portion which has a third surface that faces the second surface and a fourth surface that opposes the third surface; and a screw that tightens the light source substrate to the substrate support portion from the fourth surface without being exposed on the first surface of the light source substrate. Here, the light source substrate has a first substrate that configures the second surface and a second substrate that configures the first surface; and a through-hole that passes through the first substrate is formed in a location of the light source substrate where the screw is tightened down.

In the invention, the plurality of light-emitting elements are mounted on the first surface of the light source substrate, and the light source substrate is anchored to the substrate support plate portion disposed on the second surface using the screw. Here, the screw is tightened down into the substrate support plate portion from the opposite side as the light source substrate, and thus the screw is not exposed on the side of the first surface of the light source substrate. For this reason, portions having uneven light diffusion characteristics caused by the screw do not arise on the side of the first surface of the light source substrate, and thus it is difficult for unevenness in the brightness of the illumination light emitted from the light guiding plate to occur. In addition, the first substrate that configures the second surface of the light source substrate is a metallic plate, and the second substrate that configures the first surface of the light source substrate is a flexible wiring board that is affixed to the first substrate on the side of the first surface. The through-hole that passes through the first substrate (the metallic plate) is formed, as a hole for tightening the screw, in a location of the light source substrate where the screw is to be tightened. Accordingly, the depth of the hole into which the screw is tightened is determined primarily based on an appropriate depth depending on the thickness of the metallic plate, and thus problems caused by the hole being too deep, problems caused by the hole being too shallow, and so on do not occur.

In the invention, it is preferable for the through-hole to be formed in a location that does not overlap with the locations where the light-emitting elements are mounted. According to this configuration, the light-emitting elements can be mounted properly.

In the invention, it is preferable for a metallic layer to be formed in a region of the flexible wiring board that overlaps with the through-hole. According to this configuration, the tip of the screw is covered by the metallic layer, and thus the influence of the screw is not transmitted to the flexible wiring board.

In the invention, it is preferable for a side-end surface of the first substrate (the metallic plate) and a side-end surface of the second substrate (the flexible wiring board) to be cut surfaces that are continuous with each other. In other words, when forming the light source substrate, it is preferable for a large-scale first substrate (metallic plate) and a large-scale second substrate (flexible wiring board) to be affixed to each other, and then for the first substrate (metallic plate) and the second substrate (flexible wiring board) to be cut at the same time in order to form the individually-sized light source substrate. According to this configuration, the through-hole can be formed in the first substrate (the metallic plate) before affixing the first substrate (the metallic plate) and the second substrate (the flexible wiring board), which makes it possible to increase the ease of production.

In the invention, it is preferable for the first substrate (the metallic plate) to be thicker than the second substrate (the flexible wiring board). According to this configuration, the second substrate (the flexible wiring board) can be supported with certainty, and heat produced by the light-emitting elements can escape via the first substrate (the metallic plate).

In the invention, it is preferable for the through-hole to be a screw hole. According to this configuration, a large force is not applied to the light source substrate when tightening the screw, which makes it possible to prevent the light source substrate from deforming.

In the invention, it is preferable for the substrate support plate portion to be made of a metal. According to this configuration, the heat produced by the light-emitting elements can escape to the substrate support plate portion via the metallic plate.

It is effective for the invention to be applied in the case where the first surface of the light source substrate opposes the light-entry portion. In the case where the first surface of the light source substrate opposes the light-entry portion, it is easy for problems to arise due to the screw being exposed on the side of the first surface, but according to the invention, the occurrence of such a problem can be prevented.

The illumination apparatus according to the invention can be used in a display apparatus, and in such a case, the display apparatus includes a display panel disposed overlapping a light-emitting surface side of the light guiding plate.

The display apparatus according to the invention can also be used in an electronic device such as an LCD television.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments in which the invention has been applied in a display apparatus for a LCD television will be described hereinafter with reference to the drawings. Note that in the drawings referred to in the following descriptions, the dimensions of various layers, members, and so on have been varied in order to illustrate those layers, members, and so on at sizes that can be viewed more easily. It should also be noted that in the following descriptions, the planar directions of a light guiding plate, a liquid-crystal panel, and so on that are orthogonal to each other are taken as the X-axis direction (the direction along which the long side of the light guiding plate, the liquid-crystal panel, or the like (a display panel) extends in the drawings) and the Y-axis direction (the direction along which the short side of the light guiding plate, the liquid-crystal panel, or the like extends in the drawings), and the direction that is orthogonal to both the X-axis direction and the Y-axis direction (the direction along which the light guiding plate and the liquid-crystal panel are layered in the drawings) is taken as the Z-axis direction. Furthermore, in the drawings referred to hereinafter, one side of the X-axis direction is taken as an X1side, and the other side is taken as an X2side; one side of the Y-axis direction (the direction in which an overhang portion of the liquid-crystal panel is disposed) is taken as a Y1side, and the other direction opposed thereto is taken as a Y2side; and one side of the Z-axis direction (the direction facing the rear surface of the light guiding plate) is taken as a Z1side (a bottom side), and the other direction opposed thereto (the side toward which illumination light, display light, and so on are emitted) is taken as a Z2side (a top side).

First Embodiment

Overall Configuration

FIGS. 1A and 1Bare schematic diagrams illustrating an LCD television (electronic device) provided with a display apparatus according to a first embodiment of the invention, whereFIG. 1Ais a schematic diagram illustrating the LCD television from the exterior thereof, andFIG. 1Bis a block diagram illustrating the electrical configuration of the display apparatus.

An electronic device2000shown inFIG. 1Ais an LCD television, and includes a display apparatus100, a television frame2010, and so on. As shown inFIG. 1B, the display apparatus100includes a display panel10(a liquid-crystal panel), which will be mentioned later with reference toFIGS. 2A,2B, and so on, an image signal supply unit270that supplies image signals to the display panel10, and an illumination apparatus8that supplies illumination light to the display panel10. In addition, the display apparatus100includes a scanning line driving circuit104that drives scanning lines extending in the display panel10in the X-axis direction thereof, and a data line driving circuit101that drives data lines extending in the display panel10in the Y-axis direction thereof. A configuration in which the scanning line driving circuit104and the data line driving circuit101are both installed in the display panel10can be employed. Alternatively, a configuration in which one of the scanning line driving circuit104and the data line driving circuit101is installed in the display panel10and the other is installed in a COG-mounted driving IC in the display panel10can be employed. Furthermore, a configuration in which one of the scanning line driving circuit104and the data line driving circuit101is installed in the display panel10and the other is installed in a driving IC mounted on a circuit board that is electrically connected to the display panel10can be employed. Further still, a configuration in which both the scanning line driving circuit104and the data line driving circuit101are installed in a driving IC that is separate from the display panel10can be employed.

In this embodiment, the illumination apparatus8includes: a light guiding plate80disposed so as to overlap with the display panel10; a plurality of light-emitting elements89disposed along side-end surfaces of the light guiding plate80that are assigned as light-entry portions80a; light source substrates88on which the plurality of light-emitting elements89are mounted; and a light source driving unit280that drives the light-emitting elements89. In this embodiment, the display panel10is a laterally-long quadrangle having four sides10a,10b,10c, and10d. Of the sides10a,10b,10c, and10d, the side10ais a long side located on the one side Y1in the Y-axis direction, the side10bis a long side located on the other side12in the Y-axis direction, the side10cis a short side located on the other side X2in the X-axis direction, and the side10dis a short side located on the one side X1in the X-axis direction. In correspondence with this shape, the light guiding plate80has four side-end surfaces801,802,803, and804. Of these side-end surfaces801,802,803, and804, the side-end surface801is located on the long side corresponding to the one side Y1in the Y-axis direction, the side-end surface803is located on the long side corresponding to the other side Y2in the Y-axis direction, the side-end surface802is located on the short side corresponding to the other side X2in the X-axis direction, and the side-end surface804is located on the short side corresponding to the one side X1in the X-axis direction. In this embodiment, of the four side-end surfaces801,802,803, and804of the light guiding plate80, the two side-end surfaces801and803that are opposed in the short side direction (the Y-axis direction) serve as the light-entry portions80a. Accordingly, the light-emitting elements89are disposed along each of the two side-end surfaces801and803(the light-entry portions80a) in the light guiding plate80, and the light source substrates88extend along the respective side-end surfaces801and803(light-entry portions80a) in the light guiding plate80.

Detailed Configuration of Display Apparatus100

FIGS. 2A and 2Bare schematic diagrams illustrating the overall configuration of the display apparatus100according to the first embodiment of the invention, and are a perspective view and an exploded perspective view, respectively, of the display apparatus100.FIG. 3is an exploded perspective view showing the display apparatus100according to the first embodiment of the invention on a more detailed level.FIGS. 4A and 4Bare cross-sectional views illustrating the main elements of the display apparatus100according to the first embodiment of the invention, and are a cross-sectional view taken along the IVA-IVA line of the display apparatus100shown inFIG. 1Aand a cross-sectional view taken along the IVB-IVB line of the display apparatus100shown inFIG. 1A, respectively.

InFIGS. 2A,2B,3,4A, and4B, the display apparatus100according to this embodiment is, generally speaking, configured of the illumination apparatus8, which is referred to as a light guiding plate, and the transmissive type display panel10, which is disposed so as to overlap with the top surface of the illumination apparatus8. In this embodiment, the display panel10is configured of a transmissive type liquid-crystal panel. In the display apparatus100, the illumination apparatus8includes: a metallic first frame40(lower metal frame/metallic frame) disposed so as to cover the rear surface of the light guiding plate80on the bottom side (one side Z1in the Z-axis direction); a resinous second frame30(resin frame) that holds the ends of the display panel10above the first frame40and surrounds and holds the illumination apparatus8; and a metallic third frame50(upper metal frame) disposed on the top side (another side Z2in the Z-axis direction) of the second frame30.

The second frame30has a rectangular frame shape that holds the ends of the display panel10and surrounds the outside of the display panel10, and in this embodiment, the second frame30is configured of four frame plates31,32,33, and34that are divided into four side sections corresponding to the four sides of the display panel10. In this embodiment, the second frame30is black, and prevents the occurrence of stray light within the illumination apparatus8by functioning as a light absorption member. The frame plates31,32,33, and34respectively include: side plate portions311,321,331, and341that extend downward from the outer surface sides of the frame plates31,32,33, and34; upper plate portions315,325,335, and345(end plate portions) that are bent inward from the upper edges of the side plate portions311,321,331, and341, respectively; and protruding plate portions312,322,332, and342that protrude inward from a position partway along the height direction of the upper plate portions315,325,335, and345, respectively. Accordingly, step portions313,323,333, and343are formed by the protruding plate portions312,322,332, and342on the inner sides of the frame plates31,32,33, and34, respectively, and the display panel10is held by the step portions313,323,333, and343and the protruding plate portions312,322,332, and342. Meanwhile, the light guiding plate80, the light-emitting elements89, and so on of the illumination apparatus8are disposed on the bottom side of the protruding plate portion312.

The first frame40is formed through press-machining a thin metal plate such as SUS or the like. The first frame40includes a base plate portion45and three side plate portions42,43, and44that stand erect from the three outer edges of the base plate portion45aside from the edge corresponding to the one side Y1in the Y-axis direction, and has a rectangular box-shape whose top surface is open. The side plate portions321,331, and341of the second frame30overlap on the outside of the side plate portions42,43, and44, respectively, of the first frame40. Meanwhile, the side plate portion311of the second frame30covers the one side Y1of the first frame40in the Y-axis direction.

The third frame50is, like the first frame40, formed through press-machining a thin metal plate such as SUS or the like. The third frame50includes a rectangular upper plate portion55(end plate member) and four side plate portions51,52,53, and54formed by bending the outer edges of the upper plate portion55downward therefrom, and has a rectangular box-shape whose bottom surface is open. The side plate portions51,52,53, and54overlap on the outside of the side plate portions311,321,331, and341, respectively, of the second frame30. A rectangular window550that emits the light emitted from the display panel10is formed in the upper plate portion55, and the upper plate portion55covers the entire circumference of the outer circumferential edges of the side of the display panel10that emits display light.

The third frame50, second frame30, and first frame40configured in this manner are connected using screws (not shown), and the display panel10, illumination apparatus8, and so on are held therein as a result. Here, as shown inFIGS. 4A and 4B, flexible sheets71and72are affixed to the bottom surface and top surface, respectively, of the protruding plate portions312,322,332, and342of the second frame30. Accordingly, when the display apparatus100is assembled, the display panel10is supported by the protruding plate portions312through342via the flexible sheet72. Likewise, when the display apparatus100is assembled, the illumination apparatus8is supported via the flexible sheet71. Furthermore, when the display apparatus100is assembled, optical sheets of the illumination apparatus8(a diffusion sheet182, prism sheets183and184, and so on) are suppressed from lifting, positional skewing, and so on via the flexible sheet71.

Configuration of Display Panel10

As shown inFIGS. 2A,2B,3,4A, and4B, the display panel10includes: an element substrate11having a planar quadrangular shape and in which pixel electrodes (not shown) and the like are formed); an opposing substrate12disposed opposite to the element substrate11with a predetermined gap provided therebetween; and a sealant14that affixes the opposing substrate12and the element substrate11to each other. In the display panel10, a liquid-crystal layer13is held within a region surrounded by the sealant14. The element substrate11and the opposing substrate12are configured of light-transmissive substrates such as glass substrates. In the element substrate11, a plurality of scanning lines (not shown) extend along the X-axis direction, whereas a plurality of data lines extend along the Y-axis direction; switching elements (not shown) and pixel electrodes are provided corresponding to each location where the scanning lines and data lines intersect (not shown).

In this embodiment, the opposing substrate12is disposed on the side toward which display light is emitted, and the element substrate11is disposed on the side of the illumination apparatus8. Meanwhile, a frame-shaped layer (not shown) configured of a light-blocking layer is formed on the surface of the opposing substrate12that is opposed to the element substrate11so as to follow the inner edges of the sealant14. The display panel10is configured of a TN (twisted nematic), ECB (electrically-controlled birefringence), or VAN (vertical aligned nematic) liquid-crystal panel; the pixel electrodes are formed in the element substrate11, and a common electrode (not shown) is formed in the opposing substrate12. Note that in the case where the display panel10is an IPS (in-plane switching) or FFS (fringe field switching) liquid-crystal panel, the common electrode is provided in the element substrate11. The element substrate11may also be disposed on the side of the opposing substrate12toward which the display light is emitted. An upper polarization plate18is disposed overlapping the upper surface of the display panel10, and a lower polarization plate17is disposed between the lower surface of the display panel10and the illumination apparatus8.

In this embodiment, the element substrate11is larger than the opposing substrate12. Accordingly, the element substrate11includes an overhang portion110that extends past the end portion of the opposing substrate12on the one side Y1in the Y-axis direction, and a plurality of flexible wiring boards200are connected to the top surface of the overhang portion110. The flexible wiring boards200are connected to a circuit board250configured of a rigid board, and a control IC (not shown) that configures the image signal supply unit270described with reference toFIG. 1, a light source driving IC (not shown) that configures the light source driving unit280, and so on are mounted on the circuit board250.

Configuration of Illumination Apparatus8

FIGS. 5A,5B, and5C are schematic diagrams illustrating the configuration of the vicinity of the light source substrates88used in the illumination apparatus8of the display apparatus100according to the first embodiment of the invention;FIG. 5Ais a schematic diagram illustrating one surface of the light source substrate88;FIG. 5Bis a schematic diagram illustrating a position through which a screw is passed, from a side B in a cross-section of the display apparatus100taken along the VB-VB line shown inFIG. 1A; andFIG. 5Cis a schematic diagram illustrating a position through which a screw is passed, from a side C in a cross-section of the display apparatus100taken along the VC-VC line shown inFIG. 1A.

As shown inFIG. 3,FIGS. 4A and 4B, inFIGS. 5A,5B, and5C, the illumination apparatus8includes: the light guiding plate80disposed so as to overlap with the bottom surface of the display panel10; and a plurality of light-emitting elements89arranged from one end of the light-entry portions80a(the one side X1in the X-axis direction) toward the other end (the other side X2in the X-axis direction) with their light-emitting surfaces89afacing toward the light-entry portions80aof the light guiding plate80. In this embodiment, the plurality of light-emitting elements89are mounted on one surface881(a first surface) of the light source substrate88that extends in the X-axis direction following the light-entry portions80a. The light-emitting elements89are LEDs (light-emitting diodes) that emit white light, and emit light source light as divergent light.

In the illumination apparatus8according to this embodiment, of the side-end surfaces801,802,803, and804of the light guiding plate80, the two side-end surfaces801and803opposite to each other in the Y-axis direction are used as the light-entry portions80a. For this reason, the plurality of light-emitting elements89have their light-emitting surfaces89apointed toward the two light-entry portions80a(the side-end surfaces801and803) of the light guiding plate80, and are arranged from one end toward the other end of each of the two light-entry portions80a(the side-end surfaces801and803). Meanwhile, the light source substrates88are disposed extending along the two light-entry portions80a(the side-end surfaces801and803), respectively, and the plurality of light-emitting elements89are mounted on the respective first surfaces881of the two light source substrates88. Connectors87are mounted at one end of the first surfaces881of the light source substrates88, and the connectors87are used to supply driving currents to the light-emitting elements89via the light source substrates88.

In this embodiment, the light guiding plate80is a light-transmissive resin plate configured of an acrylic resin, a polycarbonate resin, or the like, and a reflective sheet187is disposed between a bottom surface80cof the light guiding plate80and the base plate portion45of the first frame40overlapping therebetween. Meanwhile, an optical sheet such as the diffusion sheet182, the prism sheets183and184, or the like are disposed in an overlapping manner between a top surface (a light-emitting surface80b) of the light guiding plate80and the display panel10. In this embodiment, the two prism sheets183and184are disposed so that their respective ridgelines are orthogonal to each other. Accordingly, illumination light emitted from the light-emitting surface80bof the light guiding plate80is diffused in all directions by the diffusion sheet182, and is then imparted with directionality by the two prism sheets183and184so as to have a peak in the forward direction of the display panel10. A scattering pattern configured of fine concave recesses, the printed layer of a scattering member, or the like is formed on the surface of the light guiding plate80located on the side of the reflective sheet187, and in this embodiment, the density of the scattering pattern becomes greater as the pattern progresses away from the light-emitting elements89. Accordingly, the intensity distribution of the illumination light emitted from the light guiding plate80is made uniform regardless of the distance from the light-emitting elements89. In this embodiment, many fine recesses80eare provided in the bottom surface80cof the light guiding plate80as the scattering pattern.

Steps are formed from area to area in a region of the base plate portion45of the first frame40that overlaps with the side of the light guiding plate80in which the side-end surface801is located so that a gap can be secured between the bottom surface80cof the light guiding plate80and the first frame40, and are bent away from the light guiding plate80. Through this, the reflective sheet187and bottom plate portions61of light source support members60can be held in the gap between the bottom surface80cof the light guiding plate80and the base plate portion45. Meanwhile, a recess portion is formed toward the rear surface side of the first frame40by bending the base plate portion45of the first frame40away from the light guiding plate80partially, and thus the flexible wiring boards200are bent as far as the bottom surface (rear surface) of the base plate portion45of the first frame40and the circuit board250is accommodated within the depth of the recess portion. Accordingly, the illumination apparatus8can be made thinner.

In this embodiment, the light source substrates88are disposed so that the one surfaces881(the first surfaces) on which the light-emitting elements89are mounted oppose the light-entry portions80aof the light guiding plate80. In addition, the light source substrates88are structured so that a wiring pattern, lands, and so on are provided along with an insulating layer on the one surfaces881(the first surfaces) of plate-shaped metallic plates887that extend along the light-entry portions80a. This configuration can be realized by, for example, affixing, to the one surfaces881(the first surfaces) of the metallic plates887, a flexible wiring board888in which a resin base layer, a wiring pattern, and an insulating protective layer or the like are stacked in that order. Accordingly, the lands on which the wiring pattern and the chips for the light-emitting elements89are mounted are electrically insulated from the metallic plates887. In this embodiment, the metallic plates887are configured of aluminum plates, and the metallic plates887ensure the mechanical strength of the light source substrates88and also function as heat dissipation plates that dissipate the heat from the light-emitting elements89. In this embodiment, a large-scale light source substrate88from which many individually-sized light source substrates88can be obtained is first manufactured, after which the large-scale light source substrate88is cut into the individually-sized light source substrates88. Accordingly, the side-end surfaces of the metallic plates887and the side-end surfaces of the flexible wiring board888are cut surfaces that are continuous with each other.

Here, the light source support members60that hold the light source substrates88are disposed on the other surfaces882(second surfaces) of the two light source substrates88, and the light source support members60are disposed and held between the first frame40and the second frame30. In this embodiment, the light source support members60are bar-shaped metallic components that extend along the other surfaces882(the second surfaces) of the light source substrates88. Each of the light source support members60includes the bottom plate portion61that overlaps with the base plate portion45of the first frame40, and a substrate support plate portion62that configures a wall surface protruding upward from a location partway along the width direction of the bottom plate portion61. Furthermore, each of the light source support members60includes, toward the upper end of the substrate support plate portion62(the side on the opposite side as the bottom plate portion61), an upper plate portion63bent from the substrate support plate portion62in the opposite direction as the side on which the light guiding plate80is located, and the upper plate portion63is anchored to the upper plate portion55of the third frame50and at least one of upper plate portions315and325of the second frame30using screws or the like.

In the light source support members60configured in this manner, the surfaces of the substrate support plate portions62on the side on which the light guiding plate80is located correspond to substrate holding surfaces620(third surfaces) that hold the light source substrates88, and the light source substrates88are anchored to the substrate holding surfaces620(the third surfaces) using screws86as described hereinafter. In this state, the entire surfaces of the other surfaces882(the second surfaces) (the metallic plates887) of the light source substrates88make surface contact with the substrate holding surfaces620(the third surfaces) of the light source support members60, and overlap in a tightly-fitting state. The light source support members60, meanwhile, are made of a metal such as aluminum, a ferrous metal, or the like. Accordingly, heat produced by the light-emitting elements89is transmitted to the light source support members60from the metallic plates887of the light source substrates88, and the heat in the light source support members60is then transmitted to the first frame40. This makes it possible to greatly suppress a rise in the temperature of the light-emitting elements89.

Structure for Anchoring Light Source Substrates88to Substrate Support Plate Portion62

As shown inFIGS. 5A through 5C, in the illumination apparatus8of the display apparatus100according to this embodiment, the light source substrates88are anchored to the substrate support plate portion62using screws86tightened down into through-holes625and886from the opposite side (a fourth surface side) as the light source substrates88, and the screws86are not exposed on the one surfaces881(the first surfaces) of the light source substrates88. Here, the screws86stop between light-emitting elements89in the lengthwise direction of the light source substrates88; the tip of the screw86that has been inserted into the through-hole886is in a housed state between the one surface881(the first surface) and the other surface882(the second surface) of the light source substrate88(within the thickness of the light source substrate88), and the screws86and light-emitting elements89are disposed so as not to overlap in a planar manner.

In realizing the stated configuration, the through-hole625through which the shaft portion of the screw86is passed is formed in the substrate support plate portion62, and a screw tightening hole85is formed in the light source substrates88in a location that overlaps with the through-hole625. Accordingly, the shaft portion of the screw86is tightened into the hole85. In this embodiment, the hole85in the light source substrates88is configured of the through-hole886that passes through the metallic plate887, and the one surface881(the first surface) of the through-hole886is covered by the flexible wiring board888. Meanwhile, in this embodiment, the through-hole625in the substrate support plate portion62is configured of a screw-hole in which screw threads are formed on the inner circumferential surface, and the screw86is threaded into the through-hole625.

In this state, the head of the screw86is disposed so that its surface is exposed in a space8adefined between the second frame30and the light source support members60. In this embodiment, a side plate portion is not provided in the first frame40on the one side Y1in the Y-axis direction (the side on which the overhang portion110of the display panel10is disposed, and the side to which the flexible wiring boards200are connected), and thus as shown inFIG. 5B, the space8aformed on the one side Y1of the Y-axis direction is defined by the bottom plate portion61, the substrate support plate portion62, and the upper plate portion63of the light source support member60, as well as the side plate portion311and the upper plate portion315of the second frame30. As opposed to this, the side plate portion42is provided in the first frame40on the other side Y2in the Y-axis direction, and thus as shown inFIG. 5C, the space8aformed on the other side Y2in the Y-axis direction is defined by the bottom plate portion61, the substrate support plate portion62, and the upper plate portion63of the light source support member60, the upper plate portion325of the second frame30, and the side plate portion42of the first frame40. Meanwhile, the space8aextends in the X-axis direction along the substrate support plate portion62and the like on both the one side Y1in the Y-axis direction and the other side Y2in the Y-axis direction.

Method for Anchoring Light Source Substrates88to Substrate Support Plate Portion62

FIGS. 6A through 6Gare schematic diagrams illustrating a method for manufacturing the light source substrate88used in the illumination apparatus8of the display apparatus100according to the first embodiment of the invention, and a method for anchoring the light source substrate88to the substrate support plate portion62. Hereinafter, referring toFIGS. 6A through 6G, the configurations of the light source substrate88, the through-hole886, and so on will be described in detail while describing the method for manufacturing the light source substrate88and the method for anchoring the light source substrate88to the substrate support plate portion62.

First, when manufacturing the light source substrate88, as shown inFIG. 6A, a large-scale parent metallic plate887from which a plurality of individually-sized light source substrates88can be obtained and a large-scale parent flexible wiring board888from which a plurality of individually-sized light source substrates88can be obtained are prepared, and then, as shown inFIG. 6B, the through-hole886that passes through the metallic plate887is formed in a region that does not overlap in a planar manner with the regions in which the light-emitting elements89are disposed later, as the hole85for tightening the screw into the metallic plate887.

Then, as shown inFIG. 6C, the large-scale light source substrate88is formed by affixing one surface of the flexible wiring board888to one surface of the metallic plate887in a state in which those surfaces oppose each other, using an adhesive, thermal welding, or the like. The flexible wiring board888, in which a plurality of wires are formed, is affixed from one surface that opposes the metallic plate887with a protective coating, which is configured of an insulating layer or the like so that the plurality of wires do not electrically short-circuit with the metallic plate887, provided on that surface. Meanwhile, mounting lands and the like are provided on the one surface881(the first surface) of the light source substrate88in an exposed manner, so as to enable the light-emitting elements89, the connectors87, and so on to be mounted thereto. In addition, the through-hole886provided passing through the metallic plate887is structured so as to be covered when the flexible wiring board888is affixed.

Next, as shown inFIG. 6D, the individually-sized light source substrates88are obtained by cutting the large-scale parent light source substrate88. At this time, the metallic plate887and the flexible wiring board888are also cut at the same time, and thus the side-end surface of the metallic plate887and the side-end surface of the flexible wiring board888are continuous cut surfaces. Manufacturing the light source substrate88in such a manner makes it possible to form the through-hole886in the metallic plate887before affixing the metallic plate887and the flexible wiring board888to each other, which in turn makes it possible to increase the ease of production.

Next, as shown inFIG. 6E, the light-emitting elements89, connectors87(not shown), and so on are mounted to the mounting lands of the flexible wiring board888that are exposed on the one surface881(the first surface) of the light source substrate88.

Then, as shown inFIG. 6F, the light source substrate88on which the light-emitting elements89have been mounted is placed overlapping the substrate support plate portion62, after which, as shown inFIG. 6G, the screw86is tightened down into the substrate support plate portion62from the opposite side (the fourth surface side) as the light source substrate88; this anchors the light source substrate88to the substrate support plate portion62. At this time, the tip of the screw86that has been inserted into the through-holes625and886is disposed so as not to make contact with (reach) the flexible wiring board888that has been affixed. Meanwhile, so that the optical effects (the diffusion characteristics and the reflection characteristics) are not affected at the tip of the screw86that has been inserted, the flexible wiring board888is configured of a material that is not transparent in at least that area, or the one surface881(the first surface) of the light source substrate88(the other surface of the flexible wiring board888) is processed so as to have a color such as a reflective white color.

Main Effects of this Embodiment

As described thus far, with the illumination apparatus8and display apparatus100according to this embodiment, the plurality of light-emitting elements89are disposed following the light-entry portion80aof the light guiding plate80, and the plurality of light-emitting elements89are mounted to the one surface881(the first surface) of the light source substrate88that extends along the light-entry portion80a. Here, the substrate support plate portion62of the metallic light source support member60is disposed so as to overlap with the other surface882(the second surface) of the light source substrate88, and thus heat from the light-emitting elements89can escape through the light source substrate88, the light source support member60, and the metallic first frame40.

Meanwhile, the light source substrate88is anchored to the substrate support plate portion62using the screws86, and the screws86are tightened down into the substrate support plate portion62from the opposite side (the fourth surface side) as the light source substrate88. Accordingly, the screws86are not exposed on the side of the one surface881(the first surface) of the light source substrate88. For this reason, portions having uneven light diffusion characteristics caused by the screws86do not arise on the side of the one surface881(the first surface) of the light source substrate88, and thus it is difficult for unevenness in the brightness of the illumination light emitted from the light guiding plate80to occur. In other words, the structure is such that the surfaces of the screws86are not exposed on the side of the one surface881(the first surface) of the light source substrate88, and thus portions where the optical characteristics (the diffusion characteristics and the reflection characteristics) are uneven due to the structure do not appear on the side of the one surface881(the first surface) of the light source substrate88, and thus there is no loss of uniformity of the illumination.

Meanwhile, the light source substrate88includes the metallic plate887that configures the other surface882(the second surface) and the flexible wiring board888that is affixed to the metallic plate887on the side of the one surface881(the first surface), and the through-hole886that passes through the metallic plate887is formed, as the hole85for tightening down a screw, in the location of the light source substrate88in which the screw86is tightened. Accordingly, the depth of the hole85into which the screw86is tightened is determined primarily based on an appropriate depth depending on the thickness of the metallic plate887, and thus problems caused by the hole85being too deep, problems caused by the hole85being too shallow, and so on do not occur.

In addition, the through-hole886is formed in a position that is not overlap with the locations where the light-emitting elements89are mounted, and thus in the step illustrated inFIG. 6E, the through-hole886does not interfere when mounting the light-emitting elements89. Accordingly, the light-emitting elements89can be mounted properly.

In addition, because the metallic plate887is thicker than the flexible wiring board888, the flexible wiring board888can be supported with certainty, and furthermore, the heat produced by the light-emitting elements89can be allowed to escape via the metallic plate887with certainty.

In addition, because the through-hole886is a screw hole, a large force is not applied to the light source substrate88when tightening down the screw86. Accordingly, the light source substrate88can be prevented from deforming, which in turn makes it possible to prevent the optical axes of the light-emitting elements89from tilting.

In addition, in this embodiment, the one surface881(the first surface) of the light source substrate88opposes the light-entry portion80aof the light guiding plate80. With such a configuration, it is easy for problems to arise due to the screw86being exposed on the side of the one surface881(the first surface), but according to this embodiment, the occurrence of such a problem can be prevented.

Second Embodiment

FIG. 7is a schematic diagram illustrating the light source substrate88used in the illumination apparatus8of the display apparatus100according to a second embodiment of the invention. Note that the basic configuration in this embodiment is the same as that in the first embodiment, and thus corresponding constituent elements will be given the same reference numerals, and descriptions thereof will be omitted.

As shown inFIG. 7, according to the light source substrate88used in this embodiment as well, the light source substrate88is anchored to the substrate support plate portion62using the screws86that are tightened down from the opposite side (the fourth surface side) as the light source substrate88, and the screws86are not exposed on the side of the one surface881(the first surface) of the light source substrate88. In addition, the screws86do not overlap with the light-emitting elements89. Here, the through-hole886is formed in the metallic plate887, and the side of the through-hole886located toward the one surface881(the first surface) is covered by the flexible wiring board888.

In this light source substrate88, lands889a, wires889b, and so on are formed in the flexible wiring board888in correspondence with the light-emitting elements89. In addition, in this embodiment, a metallic layer889cconfigured of the same layer as the lands889a, the wires889b, and so on is formed in a region of the flexible wiring board888that overlaps with the through-hole625. Accordingly, the tips of the screws86are covered by the metallic layer889c, and thus the diffusion characteristics at the tips of the screws86are not transmitted through the flexible wiring board888to the side of the one surface881(the first surface).

Third Embodiment

FIGS. 8A and 8Bare cross-sectional views illustrating the main elements of the display apparatus100according to a third embodiment of the invention;FIG. 8Acorresponds to a cross-section taken along the IVA-IVA line shown inFIG. 1, andFIG. 8Bcorresponds to a cross-section taken along the IVB-IVB line shown inFIG. 1. Note that the basic configuration in this embodiment is the same as that in the first embodiment, and thus corresponding constituent elements will be given the same reference numerals, and descriptions thereof will be omitted.

Although the aforementioned first and second embodiments describe a configuration in which the one surface881(the first surface) in the light source substrate88on which the light-emitting elements89are mounted is opposed to the light-entry portion80aof the light guiding plate80, in this embodiment, as shown inFIGS. 8A and 8B, the one surface881(the first surface) in the light source substrate88on which the light-emitting elements89are mounted is oriented in the direction that intersects with the light-entry portion80aof the light guiding plate80at a 90° angle. However, the light-emitting surfaces89aof the light-emitting elements89face in a direction that is perpendicular to the one surface881(the first surface) of the light source substrate88. Accordingly, the light-emitting elements89can emit the light source light into the interior of the light guiding plate80from the light-entry portion80a.

With the illumination apparatus8configured in this manner, in the light source support member60, a vertical plate portion68is opposed to the light-entry portion80aof the light guiding plate80, and in the light source support member60, the first frame40is positioned on the rear surface side of the substrate support plate portion62. Even in such a case, if a configuration in which openings are provided from area to area in the base plate portion45of the first frame40, a configuration in which recesses are provided on the rear surface side of the substrate support plate portion62, or the like is employed, screws (not shown) can be tightened into the substrate support plate portion62from the opposite side as the light source substrate88, and thus the light source substrate88can be anchored to the substrate support plate portion62using the screws. In that case as well, if the invention is applied, when forming through-holes that pass through the metallic plate887, the depth of the holes for tightening the screws is determined primarily based on the appropriate depth according to the thickness of the metallic plate887. Accordingly, the same effects as those in the first embodiment, in which problems caused by the holes being too deep, problems caused by the holes being too shallow, and so on do not arise, can be achieved.

Example of Installation in Electronic Device

Although the aforementioned embodiments describe an LCD television as an example of the electronic device2000in which the display apparatus100is installed, the display apparatus100in which the invention is applied may also be used in the display units of electronic devices such as personal computer, digital signage, car navigation devices, and mobile information terminals, in addition to LCD televisions.