Video display device

A video display device includes: a display panel that displays an image based on an input image signal; a light source substrate that includes a plurality of light sources on a main surface which is a front side of the light source substrate, and emits, toward a rear side of the display panel, light emitted from the plurality of light sources; a reflection sheet that is provided on the main surface of the light source substrate, and in which hollow partitioning walls each of which separates adjacent two light sources of the plurality of light sources are formed; and an optical member that has a plate shape, is provided between the display panel and the light source substrate, and uniformizes luminance distribution of the light emitted from the light source substrate. The reflection sheet extends to an outside of an outer peripheral edge of the optical member as viewed from the front side.

This application is a U.S. national stage application of the PCT International Application No. PCT/JP2016/003943 filed on Aug. 30, 2016, which claims the benefit of foreign priority of Japanese patent applications No. 2015-172363 filed on Sep. 1, 2015 and No. 2016-047678 filed on Mar. 10, 2016, the contents all of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a video display device including a backlight.

BACKGROUND ART

For example, various technologies for improving quality of images formed by a video display device including a backlight, such as a liquid crystal display device, have been continuously developed. A technology called direct-backlight local dimming is one of examples of these technologies.

Patent Literature 1 discloses a technology relating to local dimming

Patent Literature 2 discloses a technology which provides a lens on each of a plurality of light sources included in a direct-backlight video display device to diffuse light emitted from the plurality of light sources and thereby uniformize luminance distribution of the light emitted from the plurality of light sources.

CITATION LIST

Patent Literature

SUMMARY

According to the technologies disclosed in Patent Literature 1 and Patent Literature 2, however, luminance lowering or luminance non-uniformity may be caused at an end of an image display area of a display panel (effective area for image display, hereinafter only referred to as “effective area” as well).

Provided according to the present disclosure is a video display device capable of reducing luminance lowering or luminance non-uniformity caused at an end of an effective area of a display panel.

A video display device according to an aspect of the present disclosure includes: a display panel that displays an image based on an input image signal; a light source substrate that includes a plurality of light sources on a main surface which is a front side of the light source substrate, and emits, toward a rear side of the display panel, light emitted from the plurality of light sources; a reflection sheet that is provided on the main surface of the light source substrate, and in which hollow partitioning walls each of which separates adjacent two light sources of the plurality of light sources are formed; and an optical member that has a plate shape, is provided between the display panel and the light source substrate, and uniformizes luminance distribution of the light emitted from the light source substrate. The reflection sheet extends to an outside of an outer peripheral edge of the optical member as viewed from the front side.

The video display device according to the present disclosure is capable of reducing luminance lowering or luminance non-uniformity caused at an end of an effective area of the display panel.

DESCRIPTION OF EMBODIMENTS

(Knowledge on which the Present Disclosure is Based)

The inventors of the present application have found that following problems occur in a conventional video display device.

According to a video display device using the technology disclosed in Patent Literature 2, for example, light emitted from light sources is diffused by lenses. When the number of the light sources is relatively small, ends of an effective area of a display panel are located at relatively long distances from the light sources. In this case, luminance easily lowers. One of possible solutions for this problem may be to provide a larger number of the light sources. The larger number of light sources can secure sufficient luminance at the ends of the effective area of the display panel.

In case of the video display device which uses the technology disclosed in Patent Literature 2, however, the lens is provided for each of the plurality of light sources. In this case, the number of lenses increases in accordance with the increase in the number of light sources. Moreover, each of the lenses needs to be accurately positioned at appropriate locations for the corresponding light sources. Accordingly, there is a problem where a step for positioning the lenses increases in a manufacturing step of the video display device with increase in the number of light sources. As understood from above, the video display device which diffuses light by using lenses requires a larger number of lenses and increases the manufacturing step to reduce luminance lowering or luminance non-uniformity at the ends of the effective area of the display panel. Accordingly, reduction of these problems is not easily achieved by this type of video display device.

The inventors of the present application have examined such a configuration which provides an optical member (flatter) for uniformizing luminance distribution of light emitted from the plurality of light sources in place of the lenses provided for each of the plurality of light sources. The flatter requires less positioning accuracy than the positioning accuracy for lenses. Moreover, the flatter is provided as one optical member. Accordingly, positioning of the flatter is easier than positioning of a plurality of lenses. In this case, uniformization of luminance distribution (improvement of uniformity of luminance distribution) of light emitted from a plurality of light sources can be achieved only by providing the flatter constituting one component. Accordingly, a video display device which uses the flatter for uniformizing luminance distribution of light is allowed to increase the number of light sources more easily than the video display device which diffuses light emitted from the light sources by using lenses. More specifically, the video display device which uses the flatter is allowed to more easily position the light sources to a vicinity of an end of the effective area of the display panel, wherefore luminance at the end of the effective area of the display panel can be more easily improved. The video display device which uses the flatter may include a reflection sheet which reflects light of the light sources toward a front (display panel side). In this case, the flatter is disposed on the front (display panel side) of the reflection sheet.

However, in case of the video display device which uses the flatter and includes the light sources positioned in the vicinity of the end of the effective area of the display panel, luminance lowering or luminance non-uniformity may be caused at the end of the effective area of the display panel when a positional relationship between light reflected on an end of the reflection sheet and an end of the flatter is not sufficiently considered. Accordingly, sufficient consideration is needed for the positional relationship between the end of the reflection sheet and the end of the flatter in the video display device which uses the flatter.

A video display device according to an aspect of the present disclosure includes: a display panel that displays an image based on an input image signal; a light source substrate that includes a plurality of light sources on a main surface which is a front side of the light source substrate, and emits, toward a rear side of the display panel, light emitted from the plurality of light sources; a reflection sheet that is provided on the main surface of the light source substrate, and in which hollow partitioning walls each of which separates adjacent two light sources of the plurality of light sources are formed; and an optical member that has a plate shape, is provided between the display panel and the light source substrate, and uniformizes luminance distribution of the light emitted from the light source substrate. The reflection sheet extends to an outside of an outer peripheral edge of the optical member as viewed from the front side.

According to this configuration, the reflection sheet is so disposed as to extend to the outside of the outer peripheral edge of the optical member as viewed from the front side. In this case, the reflection sheet disposed even in an area outside the optical member can reflect light emitted from the light sources. Accordingly, luminance lowering or luminance non-uniformity can decrease even at the end of the effective area of the display panel. In other words, according to this configuration, reduction of luminance lowering or luminance non-uniformity at the end of the effective area of the display panel can be achieved by a relatively simplified configuration.

For example, an outer peripheral portion of the reflection sheet may be formed in a direction crossing the optical member, and may be disposed on an extension line of the optical member.

According to this configuration, the optical member and the reflection sheet can be disposed such that an end of the optical member and the reflection sheet face each other with a clearance left between the optical member and the reflection sheet. Accordingly, the reflection sheet can be configured such that a part of light emitted from the light sources is reflected on an end side (end side of effective area of display panel), i.e., a portion easily lowering luminance, and travels toward a center of the effective area of the display panel. Accordingly, effective reduction of luminance lowering or luminance non-uniformity can be achieved by a relatively simplified configuration even at the end of the effective area of the display panel.

For example, the outer peripheral portion of the reflection sheet may be disposed on front of the optical member.

According to this configuration, a part of light emitted from the light sources can be reflected even on the front side of the optical member toward the center of the effective area of the display panel. Accordingly, effective reduction of luminance lowering or luminance non-uniformity can be achieved by a relatively simplified configuration even at the end of the effective area of the display panel.

For example, the outer peripheral edge of the optical member may be disposed inside an effective area of the display panel as viewed from the front side. The outer peripheral portion of the reflection sheet may be disposed outside the effective area of the display panel as viewed from the front side.

According to this configuration, a clearance between the optical member and the reflection sheet can be so provided as to cross the end of the effective area of the display panel. According to this configuration, a part of light emitted from the light sources can be reflected from the outside of the end of the effective area of the display panel toward the center of the effective area of the display panel. Accordingly, effective reduction of luminance lowering or luminance non-uniformity can be achieved by a relatively simplified configuration even at the end of the effective area of the display panel.

Exemplary embodiments are hereinafter described in detail with reference to the drawings as necessary. However, excessive details may be omitted in the following description. For example, detailed description of well-known matters, and repetitive description of substantially identical configurations may be omitted. This omission is made for avoiding excessive redundancy of the following description, and facilitating understanding by those skilled in the art.

Note that each of the exemplary embodiments described herein is only presented as a specific example of the present disclosure. Numerical values, shapes, materials, constituent elements, and positions and connection manners of the constituent elements included in the following exemplary embodiments are presented by way of example, and not intended to limit the subject matters of the present disclosure. In addition, constituent elements included in the following exemplary embodiments and not contained in the independent claims defining the highest concepts are described as optional constituent elements.

Note that the accompanying drawings and the following description are presented to help those skilled in the art fully understand the present disclosure. It is therefore not intended that the subject matters defined in the appended claims be limited to those drawings and description.

Moreover, the respective figures are schematic views and not necessarily precise depictions. Furthermore, substantially identical constituent elements in the respective figures have been given identical reference numbers. Description of these elements are omitted or simplified in some cases.

First Exemplary Embodiment

Video display device1according to a first exemplary embodiment is hereinafter described with reference toFIGS. 1 through 10. It is assumed that three axes of X axis, Y axis, and Z axis are defined in the respective figures in this exemplary embodiment. The X axis is an axis extending in a direction in parallel with a long side of a display panel (horizontal direction inFIG. 1). The Y axis is an axis extending in parallel with a short side of the display panel (vertical direction inFIG. 1). The Z axis is an axis perpendicular to both the X and Y axes (direction in parallel with front-rear direction of video display device1). However, these axes are defined only for convenience and not intended to limit the present disclosure.

Video display device1according to the first exemplary embodiment is a liquid crystal display device which includes a liquid crystal display panel as a display panel, and light source substrates for illuminating the display panel from a rear side of the display panel. Video display device1is an example of a video display device. Mounted on each of the light source substrates are a plurality of light sources each of which is provided in corresponding one of areas different from each other in the display panel, and further are driver elements for driving (dimming) each of the plurality of light sources such that light is emitted from the light sources with luminance corresponding to brightness indicated by a control signal (brightness of an image within the corresponding area). Note that brightness of an image within the corresponding area in this context refers to brightness of the image in the area of the display panel illuminated by one light source (i.e., partial brightness of the image in the area corresponding to the light source).

FIG. 1is a view schematically illustrating an example of an external appearance of video display device1according to the first exemplary embodiment.

As illustrated inFIG. 1, video display device1has an external appearance of an ordinary flat panel display, and includes display panel70and light source substrates (not shown inFIG. 1). Display panel70and the light source substrates are stored in housing la having an opened front surface. According to this exemplary embodiment, surfaces of video display device1and respective constituent members of video display device1facing a user (surface on the side illustrated inFIG. 1) are referred to as front surfaces, while surfaces on the side opposite to the front surfaces (back surfaces) are referred to as rear surfaces.

FIG. 2is an exploded perspective view schematically illustrating an example of a configuration of video display device1according to the first exemplary embodiment.

FIG. 3is a plan view schematically illustrating an example of base plate10to which light source substrates20included in video display device1according to the first exemplary embodiment have been attached. Note thatFIG. 3illustrates a plan view as viewed from a front side of base plate10.

As illustrated inFIG. 2, video display device1includes base plate10, a plurality of light source substrates20, reflection sheet30, flatter40, various types of optical sheets50, mold frame60, display panel70, bezel80, connection terminal substrate91, signal processing substrate92, and power supply substrate93. These members are stored in housing1a(seeFIG. 1) to constitute video display device1. Note that video display device1further includes support members, a fastening member, a reinforcing member and the like not shown in the figures, besides the foregoing members. These not-shown parts will be described below as necessary.

Base plate10is a support substrate corresponding to a base to which light source substrates20, connection terminal substrate91, signal processing substrate92, and power supply substrate93are attached. Base plate10is made of sheet metal, for example, but may be made of other materials. Base plate10includes through holes and screw holes formed for attachment of the support members, openings formed for connection between light source substrates20via cables passing through a rear side of base plate10, and others.

Light source substrates20constitute a backlight module provided on a rear side of display panel70and illuminating the rear side of display panel70. Each of light source substrates20includes a plurality of light sources disposed on a main surface which is a front side of light source substrate20, and applies light emitted from the plurality of light sources to the rear side of display panel70. Each of light source substrates20further includes driver elements disposed on the main surface which is a front side of light source substrate20to drive each of the plurality of light sources. Each of the plurality of light sources is constituted by a light emitting diode (LED). Accordingly, each of the plurality of light sources is a point light source. As illustrated inFIG. 3, the plurality of light source substrates20having an identical shape are disposed in matrix and attached to a front surface (surface on the side toward display panel70) of base plate10. The plurality of light source substrates20constitute a direct-type backlight for illuminating display panel70. Light source substrate20will be detailed below.

Reflection sheet30is disposed on main surfaces of light source substrates20(surfaces on the side toward display panel70) where the plurality of light sources are provided. Reflection sheet30includes openings penetrated by light sources (light sources21of light source substrates20illustrated inFIG. 4). Reflection sheet30is a sheet configured such that a part of light emitted from the light sources and reflected on reflection sheet30travels toward the front side (toward display panel70). Reflection sheet30is made of white synthetic resin, for example, but may be made of other white materials. Hollow partitioning walls (seeFIG. 5) each of which protrudes toward the front side and separates adjacent two light sources of the plurality of light sources are formed in reflection sheet30. Accordingly, each periphery of the light sources is surrounded by the corresponding partitioning walls, in which condition each of the light sources illuminates an area surrounded by the corresponding partitioning walls around the corresponding light source. Reflection sheet30will be detailed below.

Flatter40is a sheet-shaped optical member provided on the front side (the side toward display panel70) of reflection sheet30to uniformize luminance distribution of light emitted from light source substrates20(to improve uniformity of luminance distribution). Flatter40transmits light emitted from the light sources not uniformly, but with distribution of light transmittance (hereinafter also abbreviated as “transmittance”) produced in each of the areas illuminated by the light sources. Note that distribution of transmittance in this exemplary embodiment refers to a state of a presence of distribution containing relatively high-transmittance portions and relatively low-transmittance portions. Flatter40is made of synthetic resin, for example, but may be made of other materials. When flatter40is absent, luminance differences may be produced in the areas illuminated by the light sources of light source substrates20in a state that each of the light sources of light source substrates20is a point light source constituted by an LED as described above. Flatter40is configured to produce transmittance distribution determined to cancel these luminance differences as predetermined transmittance distribution. Accordingly, luminance at each of different positions within the area illuminated by the corresponding light source can approach uniform luminance by the presence of flatter40, wherefore uniformity of luminance within the corresponding area can increase. As described above, flatter40is provided between display panel70and light source substrates20to uniformize luminance distribution of light emitted from light source substrates20(to increase uniformity of luminance distribution). Flatter40will be detailed below.

Optical sheets50are sheets disposed between display panel70and flatter40to perform various types of optical functions other than the function of flatter40. For example, optical sheets50include a diffusion plate which diffuses light to further increase uniformity of luminance, a prism sheet which equalizes traveling paths of light into a frontward direction to increase luminance visually recognized by the user, and others. For example, optical sheets50may be constituted by synthesis resin on which surface fine shapes corresponding to respective functions are formed. Appropriate effects of optical sheets50are produced when a distance between the light sources of light source substrates20and optical sheets50falls within a predetermined range. Accordingly, it is preferable that the distance between optical sheets50and the light sources be maintained within an appropriate range (such as a range not smaller than a second predetermined clearance).

Mold frame60is a support member which supports outer peripheries of display panel70, optical sheets50, and reflection sheet30from the rear surface. Mold frame60is made of synthetic resin, for example, but may be made of other materials. More specifically, mold frame60includes first mold frame61which supports the outer peripheral portion of display panel70from the rear of display panel70, and second mold frame62which supports the outer peripheries of optical sheets50and reflection sheet30from the rear. Mold frame60further includes cushion member63disposed between display panel70and first mold frame61, and cushion member64disposed between first mold frame61and optical sheets50(seeFIG. 10). Mold frame60may be fixed to base plate10. In addition, first mold frame61and second mold frame62of mold frame60may be formed integrally with each other.

Display panel70is a liquid crystal panel for image display constituted by a plurality of pixels arranged in matrix. Display panel70displays an image based on an image signal input to a driving circuit (not shown).

Bezel80is a support member which supports the outer periphery of display panel70from the front surface. Bezel80is made of metal, for example, but may be made of synthetic resin.

Connection terminal substrate91is a circuit substrate which includes terminals and an interface circuit for receiving image signals. Signal processing substrate92is a circuit substrate which includes a signal processing circuit for processing image signals. Signal processing substrate92further includes a circuit which generates control signals for controlling (dimming) luminance of the light sources of light source substrates20based on image signals. Power supply substrate93is a circuit substrate which includes a power supply circuit for supplying operation power (hereinafter also abbreviated as “power”) to video display device1. Connection terminal substrate91, signal processing substrate92, and power supply substrate93are attached to the rear surface of base plate10.

FIG. 4is a plan view schematically illustrating an example of a configuration of each of light source substrates20included in video display device1according to the first exemplary embodiment. A view shown in a lower part ofFIG. 4is an enlarged view of area A1ofFIG. 3.FIG. 4illustrates an example of respective members disposed on the front surface of light source substrate20. Note that a view in an upper part ofFIG. 4is an enlarged view (partial enlarged view) of an area surrounded by a broken line in the figure in the lower part ofFIG. 4. In addition, positions corresponding to areas71of display panel70illuminated by respective light sources21are indicated by alternate long and two short dashes lines in a part ofFIG. 4for convenience to facilitate visual understanding.

As illustrated inFIG. 4, the plurality of light sources21, and the plurality of driver elements22and driver elements23are mounted on light source substrate20.

Each of light sources21is provided on corresponding one of areas71different from each other in display panel70. Each of light sources21is constituted by a high-voltage LED. The high-voltage LED in this context refers to an LED constituted by a plurality of LED elements (i.e., a plurality of pn junctions) connected in series. The high-voltage LED is an LED to which higher voltage is applicable than a single LED element (low-voltage LED). Moreover, when higher voltage is applied, the high-voltage LED can provide higher light emission luminance than a single LED element in a state of flow of substantially the same current.

Each of driver elements22and driver elements23is a semiconductor element for driving light sources21based on a control signal supplied from signal processing substrate92. A control signal indicating brightness of an image in area71associated with each of light sources21is supplied from signal processing substrate92to corresponding driver element22and driver element23. In this case, driver element22and driver element23drive (dim) corresponding light source21such that light is emitted with luminance corresponding to the brightness indicated by the control signal. Each of driver elements22may be constituted by a metal-oxide semiconductor (MOS) transistor, for example. Each of driver elements23may be constituted by a semiconductor integrated circuit (IC) which generates a gate signal of driver element22from a control signal, for example.

In light source substrate20, includes openings24penetrated by support members supporting flatter40, and screw holes25which receive screws fastened to fix light source substrates20to base plate10are formed. On the other hand, base plate10to which light source substrates20are attached includes through holes11and through holes12each of which has a shape smaller than each shape of openings24, and receives a support member to stand the support member on base plate10.

Through holes11, through holes12, and screw holes (not shown) on base plate10are disposed on boundaries of adjoining areas71. Similarly, each of driver elements22, driver elements23, openings24, and screw holes25on light source substrate20are disposed on boundaries of adjoining areas71.

FIG. 5is a perspective view schematically illustrating an example of a shape of reflection sheet30included in video display device1according to the first exemplary embodiment. Positions corresponding to areas71are indicated by alternate long and two short dashes lines in a part ofFIG. 5for facilitating visual understanding.

Openings32are provided at positions corresponding to light sources21of light source substrate20disposed on the rear side of reflection sheet30. Light sources21are exposed from the rear surface of reflection sheet30through openings32toward the front surface of reflection sheet30.

Reflection sheet30is made of white synthetic resin to reflect light emitted from light sources21. Light is emitted from light sources21penetrating openings32and exposed to the front surface, a part of which light (light such as traveling rearward) is reflected on reflection sheet30toward the front side (toward display panel70).

Each of partitioning walls31formed by reflection sheet30is a hollow part which protrudes toward the front side (toward display panel70, plus side in Z axis direction (seeFIGS. 2 and 4). Each of partitioning walls31is formed at a position separating adjacent ones of openings32(i.e., adjacent ones of light sources21). Each of partitioning walls31of reflection sheet30includes intersection portion31aat which a portion extending in a first direction and a portion extending in a second direction cross each other, and linear portion31bextending in parallel with the first direction or the second direction. The first direction corresponds to the X axis direction, for example, while the second direction corresponds to the Y axis direction (seeFIGS. 2 and 4), for example. However, the first and second directions according to the present disclosure are not limited to these specific directions. For example, the respective directions may be oppositely defined.

In addition, linear portion31bof each of partitioning walls31includes recess portion35. Each of recess portions35is formed so that a part of corresponding partitioning wall31does not protrude. Each of recess portions35is formed in corresponding partitioning wall31disposed at least in either one of the first direction (such as X axis direction) and the second direction (such as Y axis direction) with respect to openings32(in other words, light sources21). In other words, each of recess portions35is formed at least in corresponding partitioning wall31disposed in the first direction with respect to corresponding opening32(light source21), or in corresponding partitioning wall31disposed in the second direction with respect to corresponding opening32(light source21).

In addition, frontward protrusion of each of partitioning walls31becomes largest on the corresponding boundary line of adjoining areas71. Each thickness of partitioning walls31decreases in the direction toward the front side (i.e., width in the direction perpendicular to the extension direction of linear portion31bdecreases). More specifically, each of partitioning walls31has inclined surface31cinclined to a display surface of display panel70. Inclined surface31cis inclined in such a direction as to decrease the thickness of partitioning wall31(seeFIG. 7). Each of inclined surfaces31cis configured such that light emitted from light source21toward partitioning wall31is reflected on inclined surface31ctoward the front side (toward display panel70).

Opening33is formed at each of recess portions35of partitioning walls31of reflection sheet30. Support members penetrate openings33as described below.

FIG. 6is a plan view schematically illustrating an example of a shape of flatter40included in video display device1according to the first exemplary embodiment. Positions corresponding to areas71are indicated by alternate long and two short dashes lines in a part ofFIG. 6for facilitating visual understanding.

As illustrated inFIG. 6, holes41in various sizes are formed in a sheet of flatter40made of synthetic resin. Flatter40controls transmittance of light by using holes41. More specifically, flatter40has distribution of transmittance within areas71in accordance with a layout (size, position, number) of holes41. Distribution of transmittance of flatter40is so designed as to cancel luminance distribution (luminance variations) which may be produced by light sources21within areas71when flatter40is absent. Flatter40therefore exhibits predetermined transmittance distribution determined to cancel luminance distribution produced by light sources21. This configuration of flatter40can improve luminance uniformity within areas71. Note that the transmittance distribution of flatter40is so designed as to obtain appropriate effects when a distance between flatter40and light sources21is maintained at a predetermined distance (hereinafter referred to as first predetermined clearance). It is therefore preferable that the clearance between flatter40and light sources21is maintained at the first predetermined clearance to obtain appropriate effects produced by flatter40.

Attachment of reflection sheet30to light source substrate20by using support member100is hereinafter described.

FIG. 7is a perspective view schematically illustrating an attachment example of reflection sheet30attached to light source substrate20in video display device1according to the first exemplary embodiment.

FIGS. 8 and 9are cross-sectional views schematically illustrating an example of a layout of respective members included in video display device1according to the first exemplary embodiment.FIG. 8illustrates a cross-sectional view taken along a line VIII-VIII inFIG. 7, whileFIG. 9illustrates a cross-sectional view taken along a line IX-IX inFIG. 7.FIG. 7does not show flatter40and optical sheets50, whileFIGS. 8 and 9illustrate flatter40and optical sheets50.

As illustrated inFIGS. 7 through 9, support member100includes wall portion110which has a shape corresponding to a shape of recess portion35of partitioning wall31. Support member100further includes shaft portion105, engaging portion120, and plate portion130. Shaft portion105penetrates through hole11of base plate10, opening24of light source substrate20, opening33of reflection sheet30, and hole41of flatter40. Base plate10, light source substrate20, and reflection sheet30are sandwiched between engaging portion120and plate portion130in a state that support member100is attached to through hole11of base plate10. Reflection sheet30is attached to light source substrate20and base plate10in this manner. Support member100is made of white synthetic resin, for example, but may be made of other materials.

In addition, a flat portion of reflection sheet30around opening32through which light source21penetrates for exposure is affixed to light source substrate20via adhesive tape36(seeFIGS. 7 and 9). Reflection sheet30is fixed to light source substrate20in this manner.

Light source21of light source substrate20penetrates from the rear surface of reflection sheet30through opening32for exposure to the front surface of reflection sheet30(seeFIGS. 7 and 9). Driver element23of light source substrate20is stored in a space inside partitioning wall31(space formed by partitioning wall31between the rear surface of reflection sheet30and the front surface of light source substrate20) (seeFIG. 8).

While not shown inFIGS. 7 through 9, light source substrate20is fixed to base plate10via a screw passing through screw hole25(seeFIG. 4) and attached to base plate10. In this case, a head portion of the screw, driver element22and others are also stored within partitioning wall31.

Moreover, a portion of shaft portion105of support member100on the front side with respect to wall portion110(the side toward display panel70, plus side in the Z axis direction inFIG. 7) penetrates particular hole41of flatter40(seeFIGS. 8 and 9). Support member100supports flatter40via support surface140provided in a notch in an upper portion of support member100by engagement between particular hole41formed in flatter40and the notch. As illustrated inFIG. 9, support surface140of support member100regulates approach of flatter40toward light source21in excess of first predetermined clearance D1.

Base plate10, light source substrate20, reflection sheet30, and flatter40are joined to each other to form one structure body in the foregoing manner by the use of support member100. Provided thereafter are various types of optical sheets50on the front side of the structure body (the side toward display panel70), and display panel70on the front side of optical sheets50to constitute video display device1as illustrated inFIG. 2. According to video display device1, display panel70is illuminated from the rear side with more uniform light emitted from light sources21of light source substrate20and passing through flatter40and the plurality of optical sheets50. In this case, brightness of the light illuminating display panel70from the rear side is controlled (dimmed) for each area71in accordance with images. Accordingly, images having more accurate contrast are displayed on display panel70.

As illustrated inFIG. 9, end150of support member100on the front side (the side toward display panel70, plus side in Z axis direction inFIG. 7) regulates approach of optical sheet50to light source21in excess of second predetermined clearance D2.

A positional relationship between reflection sheet30and flatter40is hereinafter described.

FIG. 10is a cross-sectional view schematically illustrating an example of a structure in a vicinity of an end of video display device1according to the first exemplary embodiment.

As illustrated inFIG. 10, reflection sheet30extends to an outside of outer peripheral edge42of flatter40as viewed from the front side (plus side in Z axis direction). More specifically, reflection sheet30includes outer peripheral portion37at an end of reflection sheet30on the plus side in the X axis direction. Outer peripheral portion37corresponds to a portion which reflects light emitted from light sources21. Outer peripheral portion37is formed on an outside of partitioning wall31(plus side in X axis direction). Outer peripheral portion37protrudes to the front side (plus side in Z axis direction), and to the outside (plus side in X axis direction) from partitioning wall31provided at an end on the plus side in the X axis direction (partitioning wall31illustrated inFIG. 10).

Outer peripheral portion37includes an inclined surface inclined to X-Y plane at a larger angle than a corresponding angle of inclined surface31cof partitioning wall31(seeFIG. 7). Note that outer peripheral portion37may be not required to be inclined, or may have a surface in parallel with the Z axis direction.

In addition, reflection sheet30may include flat portion38extending to the plus side in the X axis direction from an end of reflection sheet30on the side opposite to the partitioning wall31side of outer peripheral portion37. Flat portion38is a portion not reflecting light emitted from light sources21. Flat portion38is disposed between optical sheets50and second mold frame62. Alternatively, flat portion38may be disposed between optical sheets50and base plate10(not shown) when first mold frame61and second mold frame62are formed integrally with each other. Accordingly, flat portion38of reflection sheet30is a portion supported by mold frame60(or base plate10).

As described above, the light reflecting portion of reflection sheet30for reflecting light emitted from light sources21extends to the outside of outer peripheral edge42of flatter40as viewed from the front side (plus side in Z axis direction). According to the example illustrated inFIG. 10, a portion included in reflection sheet30and contacting optical sheet50, and not corresponding to flat portion38resides at the end of video display device1on the plus side in the X axis direction, and extends to a position shifted to the plus side in the X axis direction from outer peripheral edge42of flatter40by clearance d1.

In addition, outer peripheral portion37of reflection sheet30is formed in a direction crossing the planar direction of flatter40(X-Y plane), and disposed on the extension line of flatter40. Outer peripheral portion37of reflection sheet30is so disposed as to face flatter40in the planar direction of flatter40(X-Y plane).

Furthermore, outer peripheral portion37of reflection sheet30is disposed on the front side (plus side in Z axis direction) with respect to flatter40. According to the example illustrated inFIG. 10, outer peripheral portion37of reflection sheet30is disposed at a position shifted from flatter40to the plus side in the Z axis direction by clearance d2.

In addition, outer peripheral edge42of flatter40is disposed inside the effective area of display panel70as viewed from the front side (plus side in Z axis direction). It is further preferable that outer peripheral portion37of reflection sheet30be disposed outside the effective area of display panel70as viewed from the front side. For example, it is more preferable that outer peripheral portion37be disposed outside the end of the effective area of display panel70by approximately 1.2 mm.

While the end of reflection sheet30on the plus side in the X axis direction has been described with reference toFIG. 10, each of an end of reflection sheet30on the minus side in the X axis direction, an end of reflection sheet30on the plus side in the Y axis direction, and an end on the minus side in the Y axis direction has a configuration substantially similar to the configuration of the end on the plus side in the X axis direction as illustrated inFIG. 10. The respective ends not shown inFIG. 10are not repeatedly described.

[1-2. Effects and Others]

As described above, a video display device according to this exemplary embodiment includes: a display panel that displays an image based on an input image signal; a light source substrate that includes a plurality of light sources on a main surface which is a front side of the light source substrate, and emits, toward a rear side of the display panel, light emitted from the plurality of light sources; a reflection sheet that is provided on the main surface of the light source substrate, and in which hollow partitioning walls each of which separates adjacent two light sources of the plurality of light sources are formed; and an optical member that has a plate shape, is provided between the display panel and the light source substrate, and uniformizes luminance distribution of the light emitted from the light source substrate. The reflection sheet extends to an outside of an outer peripheral edge of the optical member as viewed from the front side.

Note that video display device1is an example of the video display device. Display panel70is an example of the display panel. Light sources21are an example of the light sources. Light source substrate20is an example of the light source substrate. Partitioning walls31are an example of the partitioning walls. Reflection sheet30is an example of the reflection sheet. Flatter40is an example of the optical member. Outer peripheral edge42is an example of the outer peripheral edge of the optical member.

For example, video display device1according to the example presented in the first exemplary embodiment includes: display panel70that displays an image based on an input image signal; light source substrate20that includes a plurality of light sources21on a main surface which is a front side of light source substrate20, and emits, toward a rear side of display panel70, light emitted from the plurality of light sources21; reflection sheet30that is provided on the main surface of light source substrate20, and in which hollow partitioning walls31each of which separates adjacent two light sources21of the plurality of light sources21are formed; and flatter40that is provided between display panel70and light source substrate20, and uniformizes luminance distribution of the light emitted from light source substrate20. Reflection sheet30extends to the outside of outer peripheral edge42of flatter40as viewed from the front side (plus side in Z axis direction).

An outer peripheral portion of the reflection sheet of the video display device may be formed in a direction crossing the optical member, and may be disposed on an extension line of the optical member.

The outer peripheral portion of the reflection sheet of the video display device may be disposed on front of the optical member.

The outer peripheral edge of the optical member of the video display device may be disposed inside an effective area of the display panel as viewed from the front side. The outer peripheral portion of the reflection sheet may be disposed outside the effective area of the display panel as viewed from the front side.

According to video display device1thus configured, reflection sheet30is disposed in such a position as to extend to the outside of outer peripheral edge42of flatter40as viewed from the front side (plus side in Z axis direction). In case of a video display device configured such that an area outside a flatter does not reflect light emitted from light sources, luminance lowering or luminance non-uniformity may be caused at an end of an effective area of a display panel. According to video display device1, however, reflection sheet30even in the area outside flatter40can reflect light emitted from light sources21. Accordingly, luminance lowering or luminance non-uniformity can decrease even at the end of the effective area of display panel70. In other words, according to video display device1presented in this exemplary embodiment, reduction of luminance lowering or luminance non-uniformity at the end of the effective area of display panel70can be achieved with a relatively simplified configuration.

Outer peripheral portion37of reflection sheet30of video display device1is formed in a direction crossing flatter40, and disposed on an extension line of flatter40. According to this configuration of video display device1, the end of flatter40and outer peripheral portion37of reflection sheet30can be disposed so as to face each other in a state that a clearance (clearance d1) is left between flatter40and reflection sheet30. A part of light emitted from light sources21and passing through this clearance is reflected on outer peripheral portion37and travels toward display panel70or the center of the effective area of display panel70. In other words, reflection sheet30is configured such that a part of light emitted from light sources21is reflected on an end side (end side of effective area of display panel70) i.e., a portion easily lowering luminance, and travels toward display panel70or the center of the effective area of display panel70. Accordingly, in case of video display device1, reduction of luminance lowering or luminance non-uniformity can be effectively achieved even at the end of the effective area of display panel70with a relatively simplified configuration.

Outer peripheral portion37of reflection sheet30of video display device1is disposed on front of flatter40. According to this configuration, a part of light emitted from light sources21can be reflected by reflection sheet30even on the front side of flatter40toward display panel70or the center of the effective area of display panel70. Accordingly, in case of video display device1, reduction of luminance lowering or luminance non-uniformity can be achieved even at the end of the effective area of display panel70with a relatively simplified configuration.

In addition, outer peripheral edge42of flatter40of video display device1is disposed inside the effective area of display panel70as viewed from the front side, while outer peripheral portion37of reflection sheet30is disposed outside the effective area of display panel70as viewed from the front side. According to this configuration, the clearance between flatter40and reflection sheet30(clearance d1) can be so provided as to cross the end of the effective area of display panel70in video display device1. According to this configuration of video display device1, a part of light emitted from light sources21can be reflected by reflection sheet30from the outside of the end of the effective area of display panel70toward the center of the effective area of display panel70. Accordingly, in case of video display device1, reduction of luminance lowering or luminance non-uniformity can be achieved even at the end of the effective area of display panel70with a relatively simplified configuration.

In addition, according to video display device1, the clearance (clearance d1) between outer peripheral edge42of flatter40and reflection sheet30is provided throughout outer peripheral edge42of flatter40. In this case, contact between flatter40and reflection sheet30can be prevented. Accordingly, generation of abnormal sound (noise) produced by contact between flatter40and reflection sheet30can be suppressed even when at least either flatter40or reflection sheet30vibrates with vibration of sound output from a speaker included in video display device1, for example.

Other Exemplary Embodiments

The first exemplary embodiment has been described by way of example of the technology disclosed according to the present application. The accompanying drawings and detailed description have been presented for this purpose.

Accordingly, for presentation of examples of the technology, constituent elements shown in the accompanying drawings and detailed description may contain not only constituent elements essential for solving problems, but also constituent elements not essential for solving problems. It should not be therefore directly determined that the constituent elements which are not essential elements are essential based on the consideration that these constituent elements are included in the accompanying drawings and detailed description.

Moreover, the exemplary embodiments described above are presented as examples of the technology of the present disclosure, wherefore various modifications, replacements, additions, omissions and the like may be made within the scope of the claims and an equivalent range. In addition, a different exemplary embodiment may be produced by combining respective constituent elements described in the first exemplary embodiment.

Note that errors and variations in positions, shapes and the like of respective members included in the foregoing description are allowed as long as intended advantageous effects are offered. In addition, a phrase “uniformize luminance distribution” included in the above description and the appended claims does not only mean uniformization of distribution in a strict sense. Errors and variations may be allowed as long as intended advantageous effects are offered. Improvement of uniformity of luminance distribution is also implied by this phrase.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to a video display device. More specifically, the present disclosure is applicable to a television receiver, an image recording and reproducing device, a computer display device, and others.

REFERENCE MARKS IN THE DRAWINGS