WO2013047350A1

WO2013047350A1 - Lighting device, display device and television receiver device

Info

Publication number: WO2013047350A1
Application number: PCT/JP2012/074172
Authority: WO
Inventors: 良武石元
Original assignee: シャープ株式会社
Priority date: 2011-09-28
Filing date: 2012-09-21
Publication date: 2013-04-04

Abstract

This lighting device (12) is provided with: a chassis (14) having a bottom plate (14a) and a wall plate (14c) projecting upward from the edge section of the bottom plate (14a); a plurality of light sources (17) positioned on the bottom plate (14a), and each emitting light in an upward direction from the bottom plate (14a); and a diffusion plate (15) that is positioned so as to cover the light sources (17), comprises a plate-shaped member that is capable of diffusing and transmitting the light from the light sources (17), and has a plurality of low-translucency regions (51) positioned so as to each overlap a light source (17) and having relatively low translucency, and a high-translucency region (52) comprising the area not occupied by the low-transparency regions (51) and having a relatively high translucency.

Description

Lighting device, display device, and television receiver

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

A display device including a liquid crystal panel such as a television, a mobile phone, or a portable information terminal includes a lighting device (a so-called backlight device) in addition to the liquid crystal panel. The illuminating device is arranged on the back side of the liquid crystal panel, and is configured to irradiate light spread in a planar shape toward the back side of the liquid crystal panel. Since the liquid crystal panel cannot emit light by itself, the light of the illumination device is used to display an image.

As the illumination device, for example, as shown in Patent Document 1, a so-called direct type device in which an LED light source is arranged on the back side of a liquid crystal panel is known. In this direct type illumination device, a plurality of LED light sources are dispersedly arranged on the chassis, and a diffusion plate is arranged above the chassis so as to cover these LED light sources. As the diffusion plate, for example, a plate in which diffusion particles for diffusing light are uniformly dispersed and mixed in a transparent resin plate-like member is used.

JP 2010-155853 A

(Problems to be solved by the invention)
However, since the light emitted from each LED light source of the illumination device has high directivity, it is not sufficiently diffused even if it is transmitted through the diffusion plate. Therefore, out of the planar light emitted from the lighting device through the diffuser plate, the luminance of the light transmitted through the diffuser plate in the portion covering directly above each LED light source is the diffusion of the other portion. It becomes higher than the brightness of the light transmitted through the plate. That is, luminance unevenness based on the location of the LED light source occurs in the planar light emitted from the illumination device, which is a problem.

An object of the present invention is to provide an illuminating device in which the occurrence of luminance unevenness based on the location of the light source is suppressed.

(Means for solving the problem)
A lighting device according to the present invention includes a chassis having a bottom plate, a wall plate rising from a peripheral edge of the bottom plate, and a plurality of light sources arranged on the bottom plate and each emitting light in a direction rising from the bottom plate. And a plate-like member that covers the light source and allows the light from the light source to be transmitted while diffusing, each of which is arranged to overlap the light source and is relatively light-transmissive. A diffusion plate having a plurality of low low light transmission region portions and a high light transmission region portion that is formed of a portion other than the low light transmission region portion and has a relatively high light transmission property. In the lighting device, the diffusion plate is arranged so as to cover the plurality of light sources arranged on the bottom plate. The plurality of low light transmission region portions of the diffusion plate are arranged to overlap the light source. Therefore, when the light emitted from the light source passes through the diffusion plate, the amount of light emitted from the low light transmission region is suppressed as compared with the amount of light emitted from the high light transmission region. . Therefore, it is possible to suppress the occurrence of luminance unevenness in the light emitted from the illumination device based on the location of the light source.

In the lighting device, the chassis includes a support base that is provided at an upper end portion of the wall plate and is configured in a frame shape surrounding the bottom plate to support the diffusion plate, and the diffusion plate has a peripheral portion. Position for aligning the low light transmission region with respect to the light source so as to cover the light source in a state supported by the support and so that the high light transmission region overlaps the light source You may have a matching part. In the illumination device, the diffusion plate includes an alignment portion for aligning the low light transmission region with respect to the light source so that the low light transmission region overlaps with the light source. The positional deviation between the light transmission region and the light source is suppressed.

In the illumination device, the alignment unit may be provided at a predetermined position of the diffusion plate that overlaps an inner edge of the support when the low light transmission region overlaps the light source. In the illumination device, when the alignment portion is provided at the predetermined location, the low light transmission region portion and the light source are aligned by overlapping the alignment portion at the predetermined location.

In the illumination device, the alignment portion may have a shape along an inner edge portion of the support base. In the illumination device, when the alignment portion has a shape along the inner edge portion of the support base, the alignment portion can be easily overlapped with the inner edge portion of the support base.

In the illuminating device, the alignment portion may be formed of a coating film formed on a front plate surface at the peripheral edge of the diffusion plate. In the illuminating device, when the alignment portion is formed of a coating film formed on the front surface of the peripheral edge of the diffusion plate, the alignment portion is diffused using a known coating device or the like. Easy to form on a plate.

In the illuminating device, the alignment portion may be formed by cutting out the peripheral portion of the diffusion plate. In the lighting device, when the alignment portion is formed by cutting out the peripheral portion of the diffusion plate, the position of the alignment portion and the position of the support base are confirmed from the front side of the diffusion plate. Easy to do.

In the illumination device, the diffusion plate may have a rectangular shape, and the alignment portion may be provided at a diagonal of the diffusion plate. In the illuminating device, when the diffusion plate has a rectangular shape and the alignment portion is provided at a diagonal of the diffusion plate, the low light transmission region portion and the light source can be easily aligned.

In the lighting device, the light source may be an LED.

The display device according to the present invention includes the illumination device and a display panel that displays an image using light from the illumination device.

In the display device, the display panel may be a liquid crystal panel in which liquid crystal is sealed between a pair of substrates.

A television receiver according to the present invention includes the display device.

(The invention's effect)
ADVANTAGE OF THE INVENTION According to this invention, the illuminating device with which generation | occurrence | production of the brightness nonuniformity based on the arrangement | positioning location of a light source was suppressed can be provided.

1 is an exploded perspective view showing a schematic configuration of a television receiver according to Embodiment 1 of the present invention. Exploded perspective view showing schematic configuration of liquid crystal display device A-A 'line cross-sectional view in FIG. The top view of the illuminating device of the state from which the flame | frame and the optical member were removed Top view of diffuser plate Enlarged view of the back side of the diffuser Explanatory drawing which shows the state with which the diffuser plate was mounted on the receiving plate in the illuminating device Explanatory drawing which shows the arrangement | positioning relationship between a positioning part and a backing plate The top view of the diffusion plate utilized with the illuminating device which concerns on Embodiment 2. FIG. The top view of the diffusion plate utilized with the illuminating device which concerns on Embodiment 3. FIG. The top view of the diffuser plate utilized with the illuminating device which concerns on Embodiment 4. FIG. The enlarged view of the diffusion plate utilized with the illuminating device which concerns on Embodiment 5. FIG.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. In the present embodiment, the lighting device 12, the liquid crystal display device 10, and the television receiver TV are illustrated. A part of each drawing shows an X-axis, a Y-axis, and a Z-axis, and each axis is drawn so as to be a common direction in each drawing. 2 and 3, the upper side is the front side, and the lower side is the back side.

FIG. 1 is an exploded perspective view showing a schematic configuration of a television receiver TV according to Embodiment 1 of the present invention. As shown in FIG. 1, the television receiver TV of the present embodiment mainly includes a liquid crystal display device (display device) 10, front and back cabinets Ca and Cb that are stored so as to sandwich the liquid crystal display device 10, and a power source P. And a tuner T and a stand S. The liquid crystal display device 10 is supported by the stand S so that the display surface is along the vertical direction (Y-axis direction).

FIG. 2 is an exploded perspective view showing a schematic configuration of the liquid crystal display device 10, and FIG. 3 is a cross-sectional view taken along the line A-A 'in FIG. The liquid crystal display device 10 has a horizontally long rectangular shape as a whole when viewed from the front side. The liquid crystal display device 10 includes a liquid crystal panel 11, an illumination device (backlight device 12) disposed on the back side of the liquid crystal panel 11, and a frame-shaped bezel 13 that covers the front side of the liquid crystal panel 11.

The liquid crystal panel 11 has a horizontally long rectangular shape as a whole when viewed from the front side. The liquid crystal panel 11 includes a pair of transparent glass substrates facing each other and a liquid crystal layer sealed between the substrates. Among these substrates, one glass substrate disposed on the back side (back side) is a so-called thin film transistor (hereinafter, TFT) array substrate, and the other glass substrate disposed on the front side is a so-called color filter ( Hereinafter, it is a CF) substrate.

The TFT array substrate is mainly composed of a transparent glass plate on which a plurality of TFTs as switching elements and a plurality of transparent pixel electrodes connected to the drain electrodes of each TFT are provided in a matrix. Become. Individual TFTs and pixel electrodes are provided for each pixel, and are partitioned by a plurality of gate wirings and a plurality of source wirings provided on the glass plate so as to cross each other. . Note that the gate electrode in each TFT is connected to the gate wiring, and the source electrodes are connected to the source wiring.

The CF substrate is mainly formed on a transparent glass plate so that the CF composed of each color such as red (R), green (G), and blue (B) corresponds to each pixel of the TFT array substrate. It consists of what was provided in matrix form. Each CF is partitioned by a light-shielding black matrix (BM) provided in a lattice pattern on the glass plate. A transparent counter electrode or the like facing the pixel electrode of the TFT array substrate is provided on the CF and the BM.

The liquid crystal panel 11 is configured to supply image data and various control signals necessary for displaying an image from the drive circuit substrate to the above-described source wiring, gate wiring, counter electrode, and the like. Drives in a matrix system. The liquid crystal panel 11 includes polarizing plates on the front side and the back side, respectively. These polarizing plates are provided so as to sandwich the pair of glass substrates.

Next, the lighting device 12 will be described. As shown in FIGS. 2 and 3, the illumination device (backlight device) 12 is a box-shaped unit having an opening 14 b that emits light from the light source 17 on the light emitting unit 12 a side (the liquid crystal panel 11 side). The chassis 14, the optical member 15 (the diffusing plate 15 a and the optical sheet 15 b) disposed so as to cover the opening 14 b of the chassis 14, and the peripheral portion of the optical member 15 while being disposed along the peripheral portion of the chassis 14 Is held between the chassis 14 and the frame 16. Further, in the chassis 14, as shown in FIG. 2 and the like, an LED (Light Emitting Diode) 17 as a light source, an LED board (light source board) 18 on which the LED 17 is mounted, and an LED 17 on the LED board 18 A diffusing lens 19 attached at a corresponding position is provided. In addition, a reflection sheet 21 that reflects the light in the chassis 14 toward the optical member 15 is provided in the chassis 14. The light emitted from the illuminating device 12 toward the back surface of the liquid crystal panel 11 is planar light having substantially uniform luminance.

The chassis 14 has a shallow box shape with an upper opening, and is formed by pressing a plate material made of a metal material such as aluminum. The chassis 14 includes a bottom plate 14a having a rectangular shape like the liquid crystal panel 11, a side plate (wall plate) 14c rising from the end of each side of the bottom plate 14a, and a receiving plate (outwardly extending from the upper end of each side plate 14c). Support base) 14d. A plurality of LEDs 17 as light sources are arranged on the bottom plate 14a of the chassis 14 as described later. In addition, the part enclosed by the upper end part of each side plate 14c becomes the opening part 14b of the chassis 14, and comes from this opening part 14b. A frame 16 and an optical member 15 are mounted on each receiving plate 14d of the chassis 14 from the front side. The frame 16 is screwed to the receiving plate 14d.

As shown in FIG. 2, the optical member 15 has a horizontally long rectangular shape when seen in a plane, like the liquid crystal panel 11 and the chassis 14. As shown in FIG. 3, the optical member 15 covers the opening 14 b of the chassis 14 with the peripheral edge thereof being placed on a receiving plate (support) 14 d, and between the liquid crystal panel 11 and the LED 17. Arranged. The optical member 15 includes a diffusion plate 15a disposed on the back side and an optical sheet 15b disposed on the front side.

The diffusion plate 15a is a rectangular plate-like member having a predetermined thickness, and has a function of diffusing transmitted light. The details of the diffusion plate 15a will be described later.

The optical sheet 15b is smaller in thickness than the diffusion plate 15a and has a sheet shape. In the case of this embodiment, the two optical sheets 15b are used in a stacked state. Examples of the optical sheet 15b include a diffusion sheet, a lens sheet, a reflective polarizing sheet, and the like, which are appropriately selected and used. In the present embodiment, a lens sheet (lower side in FIG. 2) and a reflective polarizing sheet (upper side in FIG. 2) are selected as the optical sheet 15b. The optical sheet 15b is used in a state of being laminated on the diffusion plate 15a.

As shown in FIG. 2, the frame 16 has a frame shape along the periphery of the liquid crystal panel 11 and the optical member 15. The periphery of the optical member 15 is sandwiched between the frame 16 and each receiving plate 14d (see FIG. 3). The frame 16 receives and supports the peripheral edge of the liquid crystal panel 11 from the back side. The frame 16 can sandwich the peripheral portion of the liquid crystal panel 11 with the bezel 13 arranged on the front side (see FIG. 3). The frame 16 is made of resin and has a light shielding property.

The LED 17 has a configuration in which an LED chip is sealed with a resin material on a substrate portion fixed to the LED substrate 18. The LED chip has a single main emission wavelength, and specifically, an LED chip that emits blue light in a single color is used. On the other hand, a phosphor that converts blue light emitted from the LED chip into white light is dispersed and blended in the resin material for sealing the LED chip. Thus, the LED 17 can emit white light. The LED 17 is a so-called top type, and a surface opposite to the mounting surface with respect to the LED substrate 18 is a light emitting surface. The light emitted from the LED 17 is set so as to be directed toward the back surface of the liquid crystal panel 11 (in the direction of rising from the bottom plate 14a).

FIG. 4 is a plan view of the lighting device 12 with the frame 16 and the optical member 15 removed. As shown in FIG. 4, the LED substrate 18 has a long shape (band shape), and is fixed on the bottom plate 14 a of the chassis 14 using a rivet-shaped fixing member 20. A plurality of LEDs 17 are surface-mounted on the LED substrate 18. The LEDs 17 are linearly arranged at equal intervals along the longitudinal direction of the LED substrate 18 on the LED substrate 18. In the case of this embodiment, the three LED boards 18 are linearly connected to each other via the connector 18a. The LED substrate 18 in a linearly connected state is fixed on the bottom plate 14a so as to be along the long side direction (X-axis direction) of the bottom plate 14a. Note that the LEDs 17 of the LED substrates 18 connected to each other are electrically connected to each other.

Further, the LED boards 18 are arranged in parallel on the bottom plate 14a at intervals from each other. Therefore, the plurality of LEDs 17 are arranged in a matrix on the bottom plate 14a of the chassis 14. That is, the LEDs 17 are distributed on the bottom plate 14a. In the present embodiment, the distance between the LEDs 17 adjacent in the longitudinal direction (X-axis direction) and the short-side direction (Y-axis direction) of the LED substrate 18 is set to be substantially constant.

The LED substrate 18 is mainly composed of a long (band-shaped) base material made of a metal material such as aluminum, an insulating layer made of a synthetic resin formed on the base material, and copper formed on the insulating layer. A reflective layer (solder resist layer) made of a metal film such as a foil and electrically connected to the LED 17 and a white insulating film uniformly formed on the insulating layer so as to cover the wiring pattern ). The LEDs 17 on the LED substrate 18 are connected to each other in series by the wiring pattern. The LED board 18 is provided with a relay connector 18b. Each LED 17 on the LED substrate 18 is electrically connected to an external control circuit (not shown) via the relay connector 18b. The lighting / extinguishing control of each LED 17 is collectively performed by the control circuit.

The diffusion lens 19 is made of a synthetic resin material that is substantially transparent and has a higher refractive index than air. Examples of the synthetic resin material include acrylic resin and polycarbonate. The diffuser lens 19 has a substantially circular shape when viewed from the front side, and is attached to the LED substrate 18 so as to cover the LEDs 17. One diffusion lens 19 is assigned to each LED 17. The diffusion lens 19 is fixed on the LED substrate 18 using an adhesive so that the center thereof overlaps the center of the LED 17. Since the light emitted from the LED 17 has high directivity (strong), the directivity is lowered (weak) to some extent by passing through the diffusion lens 19.

The reflection sheet 21 is made of a synthetic resin and is made of a white sheet-like processed product having a surface with excellent light reflectivity. Specifically, it is manufactured from a foamed plastic sheet such as a foamed polyethylene terephthalate sheet. As shown in FIGS. 2 and 4, the reflection sheet 21 has a size laid over substantially the entire inner surface of the chassis 14, and collects all the LED boards 18 in the chassis 14 from the front side. Can be covered. The reflection sheet 21 has a function of efficiently raising the light in the chassis 14 toward the optical member 15 side.

The reflection sheet 21 extends along the bottom plate 14a of the chassis 14, and has a substantially rectangular bottom portion 21a having a size covering most of the bottom plate 14a, and an end portion of each side of the bottom portion 21a from the end portion to the front side. The four rising portions 21b that are inclined with respect to the bottom portion 21a and the extending portions 21c that extend outward from the upper ends of the respective rising portions 21b and are placed on the receiving plate 14d of the chassis 14 It consists of and. The bottom 21a of the reflection sheet 21 is provided with a lens insertion hole 21d that exposes each diffusion lens 19 (each LED 17). That is, the bottom 21a is provided with a plurality of lens insertion holes 21d in a matrix. As shown in FIG. 4, the lens insertion hole 21 d has a circular shape, and its diameter dimension is set larger than that of the diffusion lens 19. In addition to the lens insertion hole 21d, the bottom 21a is appropriately provided with an opening for exposing the connector 18a and the like. The reflection sheet 21 is fixed to the LED board 18 by using a rivet-like fixing member 20 for fixing the LED board 18 to the bottom plate 14a.

As shown in FIGS. 2 to 4, the support member 22 generally has a shape protruding from the bottom plate 14 a of the chassis 14 toward the front side. The base side of the support member 22 has a rivet shape, and has a function of fixing the LED substrate 18 to the bottom plate 14a, like the fixing means 20. Moreover, the front end side of the support member 22 has a rod shape and has a function of supporting the optical member 15 from the back side. The support member 22 can maintain the positional relationship between the LED 17 and the optical member 15 (the positional relationship in the Z-axis direction) constant, and can also restrict the deformation (deflection) of the optical member 15.

Here, the diffusion plate 15a will be described in detail with reference to FIGS. FIG. 5 is a plan view of the diffusion plate 15a, and FIG. 6 is an enlarged view of the plate surface 115b on the back side of the diffusion plate 15a. As shown in FIG. 5, the diffusion plate 15a has a horizontally long rectangular shape. The diffusion plate 15a includes a plate-like base material 115 in which a large number of diffusion particles for diffusing light are dispersed and blended in a substantially transparent resin-made plate-like member having a predetermined thickness, and a back side of the plate-like base material 115. A plurality of low light transmission region portions 51 formed on the plate surface (back surface) 115b, and alignment portions 53 formed at the four corners of the plate surface (front surface) 115a on the front side of the plate-like substrate 115, respectively. ing. Of the plate surface of the diffusion plate 15a (plate-like substrate 115), the surface facing the LED 17 is the back surface 115b, and the opposite surface (that is, the surface facing the liquid crystal panel 11) is the surface 115a. The back surface 115b of the diffusion plate 15a functions as a light incident surface on which light from the LED 17 is incident. On the other hand, the front surface 115 a of the diffusion plate 15 a functions as a light emitting surface that emits light incident from the back surface 115 b toward the liquid crystal panel 11.

The plate-like substrate 115 is set to have a substantially uniform light transmittance and light reflectance throughout. As resin which comprises the plate-shaped base material 115, acrylic resins, such as PMMA, and a polycarbonate are mentioned, for example. Examples of the diffusion particles dispersed and blended in the plate-like base material 115 include silica, alumina, and titania. The light transmittance α in the plate-like substrate is about 88%, and the light reflectance is about 12%.

The low light transmission region portion 51 is configured by a white coating film formed in a layer shape on the back surface 115b of the plate-like substrate 115. When the diffusing plate 15a (plate-like base material 115) is viewed in plan, the respective light transmission region portions 51 have a circular shape and are arranged in a matrix. The position of each low light transmission region 51 is set to overlap each LED 17 (each diffusion lens 19) facing the back surface 115 b when the diffusion plate 15 a is attached to a predetermined position of the lighting device 12. The shape and size of the low light transmission region 51 are set to be substantially the same as the shape and size of the diffusion lens 19 that covers the LED 17.

The low light transmission region 51 is formed, for example, by printing a paste-like white paint containing a metal oxide such as titanium oxide on the back surface 115b of the plate-like substrate 115. Examples of the printing method include screen printing and inkjet printing. The light reflectance of the low light transmission region 51 is, for example, about 75%, which is higher than the light reflectance (about 12%) of the plate-like base material 115 itself. That is, the light transmittance of the low light transmission region 51 is about 25%. In the back surface 115b of the diffusion plate 15a (plate-like base material 115), a region where the low light transmission region 51 is not formed is a high light transmission region 52.

The light reflectance of the plate-like substrate 115 itself exemplified in the present embodiment is based on the average light reflectance within the measurement diameter measured by LAV (measurement diameter φ25.4 mm) of CM-3700d manufactured by Konica Minolta. It is. The light reflectance of the low light transmission region 51 itself is based on a value obtained by forming the low light transmission region 51 on one surface of the glass substrate and measuring the formation surface by the measuring means.

The positioning unit 53 is used as a mark for positioning when the diffusion plate 15a is attached to a predetermined position of the lighting device 12. The alignment part 53 of this embodiment consists of what was drawn with the black coating material (coating film) in the predetermined part of the four corners in the peripheral part of the surface 115a. In other embodiments, the paint may be made of other colors such as white. Thus, when the alignment part 53 consists of a coating material (coating film), since a well-known printing technique etc. can be utilized, there exists an advantage that the alignment part 53 is easy to form. FIG. 7 is an explanatory view showing a state where the diffusion plate 15a is placed on the receiving plate 14d in the lighting device 12, and FIG. 8 is an explanatory view showing an arrangement relationship between the alignment portion 53 and the receiving plate 14d. . The diffusing plate 15 a is attached to the lighting device 12 in a state where it is placed on the receiving plate 14 d of the chassis 14. The receiving plate (support base) 14d has a frame shape as shown in FIG. 4 and the like, and the peripheral portion of the back surface 115b of the diffusion plate 15a is addressed to the frame-shaped receiving plate 14d. An extension part 21c of the reflection sheet 21 is placed on the receiving plate 14d, and the diffusion plate 15a is placed on the receiving plate 14d via the extension part 21c.

7 and 8, the receiving plate 14d is set so that a slight margin (space) S1 is formed outside the diffusion plate 15a even when the diffusion plate 15a is placed. That is, when the size or the like of the receiving plate 14d is set, the dimensional error of the diffusion plate 15a, thermal expansion, and the like are taken into consideration. Therefore, unless the diffusion plate 15a is sandwiched and fixed between the receiving plate 14d and the frame 16, the position on the receiving plate 14d can be changed. By the way, from the viewpoint of suppressing the occurrence of uneven brightness due to the location where the LED (light source) 17 is arranged, each low light transmission region 51 provided in the diffusion plate 15a is placed on the receiving plate 14d. It is most preferable to be disposed directly above each diffusion lens 19 (each LED 17). That is, when the diffusion plate 15a is viewed from the front side, each low light transmission region 51 and each diffusion lens 19 (each The LEDs 17) preferably overlap each other. Thus, each low light transmission region 51 is overlapped with each diffusion lens 19 (each LED 17), so that the light emitted from the diffusion plate 15 a of the portion arranged directly above each LED 17 to the liquid crystal panel 11 side. Is suppressed from being excessively higher than that of light emitted from other portions.

The alignment portion 53 overlaps the inner edge portion 114 of the receiving plate 14d when the respective low light transmission region portions 51 and the respective diffusion lenses 19 overlap each other in a state where the diffusion plate 15a is placed on the receiving plate 14d. Is set. That is, when the diffusing plate 15a is placed on the receiving plate 14d, if the alignment portion 53 overlaps the inner edge portion 114 of the receiving plate 14d, each low light transmission region portion 51 is arranged directly above each diffusing lens 19. Each of the diffusing lenses 19 can be superposed.

The alignment portion 53 of the present embodiment includes a linear portion along the long side direction of the diffusion plate 15a and a linear portion along the short side direction of the diffusion plate 15a, and has a substantially L shape as a whole. ing. The alignment portion 53 having such a shape is aligned with the inner edge portion 114 of the receiving plate 14d in a state where the diffusion plate 15a is viewed from the front side. Since the inner edge portion 114 of the receiving plate 14d is seen through the diffusion plate 15a when the diffusion plate 15a is placed on the receiving plate 14d, the alignment portion 53 is checked while checking the position of the inner edge portion 114. , It is possible to accurately align with the inner edge portion 114. In the present embodiment, since a part of the reflection sheet 21 (extension part 21c) is placed on the receiving plate 14d, the alignment part 53 actually follows the shape of the inner edge part 114. The reflective sheet 21 is positioned with respect to the portion (that is, the boundary portion between the extending portion 21c and the rising portion 21b).

The diffusion plate 15a of the present embodiment is provided with alignment portions 53 at the four corners, respectively, and is easily aligned with the inner edge portion 114 of the receiving plate 14d. In addition, it is preferable to provide one alignment portion 53 at least one at a diagonal of the diffusion plate 15a (two in total). Thus, if the alignment part 53 is provided in the diagonal of the diffusion plate 15a, the diffusion plate 15 can be reliably positioned on the receiving plate 14.

A predetermined optical sheet 15b is laminated on the diffusion plate 15a positioned on the receiving plate 14d. The diffusion plate 15a is sandwiched and fixed between the receiving plate 14d and the frame 16 together with the optical sheet 15b in a positioned state.

Each low light transmission region 51 formed in a matrix on the back surface 115b of the diffusion plate 15a has a light transmittance set lower than that of the high light transmission region 52 formed of other regions. Therefore, when light is emitted from each LED 17 (each diffusion lens 19) toward the front side, most of the light is reflected by each low light transmission region 51 of the diffusion plate 15a and dispersed in various directions. Is done. A part of the light passes through each low light transmission region 51 and is emitted from the front plate surface 115a while being diffused by the diffusion particles in the diffusion plate 15a. That is, the light from the LED 17 (diffuse lens 19) is not incident on a specific portion of the diffuser plate 15a disposed immediately above it but incident on the diffuser plate 15a in a widely dispersed state. become. Further, most of the light emitted from the LED 17 and incident on the high light transmission region 52 of the diffusion plate 15a is emitted from the front plate surface 115a while being diffused by the diffusion particles in the diffusion plate 15a. . Therefore, as the whole diffusing plate 15a, the light emitted from each LED 17 (each diffusing lens 19) can be emitted toward the liquid crystal panel 11 as light that spreads substantially uniformly in a planar shape.

The liquid crystal panel 11 is fixed in a state where its peripheral edge is sandwiched between a frame 16 and a frame-like bezel 13 that covers the frame 16 from above. The bezel 13 is fixed to a part of the chassis 14 together with the frame 16 and the like using fixing means such as screws.

The liquid crystal display device 10 causes each LED 17 of the illumination device 12 to emit light when displaying an image on the display surface 11 a of the liquid crystal panel 11. When each LED 17 emits light, the light passes through the diffusion lens 19 and travels toward the diffusion plate 15a disposed on the front side (upper side) in a state where it is diffused to some extent. The light that has entered the diffusion plate 15a is emitted from the front plate surface 115a as light that spreads substantially uniformly in a planar shape as a whole. The emitted planar light then passes through the optical sheet 15b and illuminates the back surface 11b of the liquid crystal panel 11. The liquid crystal panel 11 displays an image on the surface (display surface 11a) using the light from the illumination device 12.

The illuminating device 12 of this embodiment can emit the light emitted from each LED 17 from the light emitting portion 12a as light spread substantially uniformly in a planar shape by transmitting the light through the diffusion plate 15a. In the planar light emitted from the illumination device 12 of the present embodiment, the occurrence of luminance unevenness based on the arrangement location of the LED 17 is suppressed. That is, in the planar light, it is suppressed that the luminance of the portion corresponding to the position directly above each LED 17 (arrangement position) is higher than the luminance of the other portions. Further, the liquid crystal display device 10 using the illumination device 12 can also display an image in which the occurrence of luminance unevenness is suppressed.

In the illuminating device 12 according to the present embodiment, alignment portions 53 are provided at four corners (predetermined portions) on the front side of the peripheral portion of the diffusion plate 15. Therefore, when positioning the diffusion plate 15 at a predetermined position on the receiving plate 14d of the chassis 14, if all the alignment portions 53 are overlapped along the inner edge portion 114 of the receiving plate 14d, the diffusion plate 15 is provided. Each low light transmission region 51 is arranged directly above each LED 17 (each diffusing lens 19) arranged on the bottom plate 14a. Therefore, the diffuser plate 15 used in the illumination device 12 of the present embodiment uses the alignment unit 53 to accurately align the low light transmission region 51 directly above the LED 17 (diffuse lens 19). be able to.

In the present embodiment, the alignment portion 53 is made of a coating film (paint) formed on the front plate surface 115a at the peripheral edge of the diffusion plate 15. Therefore, when the diffusion plate 15 is placed on the receiving plate 14d of the chassis 14, the alignment portion 53 is not peeled off due to contact (friction) with the receiving plate 14d. Therefore, the alignment portion 53 is preferably provided on the front plate surface 115a of the front plate surface 115a and the back plate surface 115b of the diffusion plate 15.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the following embodiments, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted. In the present embodiment, a diffusion plate 15A used in the lighting device according to the second embodiment is illustrated.

FIG. 9 is a plan view of a diffusion plate 15A used in the illumination device according to the second embodiment. The basic configuration of the illumination device of the present embodiment is the same as that of the first embodiment. However, the configuration of the diffusion plate 15A is different from that of the first embodiment. Specifically, unlike the first embodiment, the alignment portion 53A of the diffusion plate 15A is formed of a cutout portion 53A that penetrates the diffusion plate 15A in the thickness direction.

As shown in FIG. 9, alignment parts 53A are provided at the four corners of the rectangular diffusion plate 15A. As described above, the alignment portion 53A has a shape penetrating the diffusion plate 15A (plate-like base material 115) in the thickness direction. When the alignment portion 53A is viewed from the front side plate surface 115a, the alignment portion 53A has a substantially L-shape like the alignment portion 53 of the first embodiment. The alignment portion 53A is formed by cutting out the plate-like base material 115 along the thickness direction. Similarly to the first embodiment, the alignment portion 53A of this embodiment is overlapped with the inner edge portion 114 of the receiving plate 14d in a state where the diffusion plate 15A is placed on the receiving plate 14d of the chassis 14. Then, each low light transmission region portion 51 and each diffusion lens 19 in the diffusion plate 15A overlap each other. Accordingly, the planar light emitted from the illumination device of the present embodiment also becomes light that spreads substantially uniformly in the planar shape, as in the first embodiment, and luminance unevenness due to the location where the LED 17 (diffuse lens 19) is disposed. Has been reduced.

When the alignment portion 53A has a hole shape penetrating the diffusion plate 14A (when the diffusion plate 15A of the present embodiment includes a cutout portion), the alignment portion 53A is addressed to the receiving plate 14d. Then, the inner edge portion 114 of the receiving plate 14d can be directly confirmed through the alignment portion 53A. As described above, when the alignment portion 53A has a shape penetrating the diffusion plate 14A, it is easy to align the alignment portion 53A and the inner edge portion 114 while confirming the position of the inner edge portion 114 of the receiving plate 14d. Become.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. In the present embodiment, a diffusion plate 15B used in the lighting device according to the third embodiment is illustrated. FIG. 10 is a plan view of a diffusion plate 15B used in the illumination device according to the third embodiment. The basic configuration of the illumination device of the present embodiment is the same as that of the first embodiment. However, the configuration of the diffusion plate 15B is different from that of the first embodiment. Specifically, unlike the first embodiment, the alignment portion 53B of the diffusing plate 15B includes a portion obtained by cutting off four corners (corner portions) of the diffusing plate 15B.

The diffusion plate 15B is formed by cutting out a part of the diffusion plate 15B (plate-like base material 115), like the alignment portion 53A of the diffusion plate 15A. In the case of the present embodiment, the alignment portion 53B has a shape in which the four corners of the plate-like base material 115 having a rectangular shape as a whole are cut out in parallel along the long side direction and the short side direction, respectively. Then, the surface along the long side direction and the surface along the short side direction of the diffusion plate 15B remaining after being cut out are set to be along the inner edge portion 114 of the receiving plate 14d. Then, when the portion 153 where the surface along the long side direction and the surface along the short side direction remaining after being cut off is placed on the receiving plate 14d when the diffusion plate 15B is placed on the receiving plate 14d, the adjacent inner edge It is set so as to overlap with a portion where the portions 114 intersect (a corner portion of the receiving plate 14d). That is, the four diffusion portions 15B provided on the diffusion plate 15B are overlapped with the corners of the four receiving plates 14d, so that the diffusion plate 15B can be positioned at a predetermined position of the lighting device.

Thus, the notch-shaped alignment portions 53B may be provided at the four corners of the diffusion plate 15B. By providing the notch-shaped alignment portion 53B as described above, the inner edge portion 114 of the receiving plate 14d can be directly confirmed from the front side of the diffusion plate 15B through the alignment portion 53B, as in the second embodiment. Therefore, the diffusion plate 15B of the present embodiment can easily align the alignment portion 53B and the inner edge portion 114 while confirming the position of the inner edge portion 114 of the receiving plate 14d. Further, the planar light emitted from the illumination device of the present embodiment is also light that spreads substantially uniformly in the planar shape, as in the first embodiment, and luminance unevenness due to the location of the LED 17 is reduced.

<Embodiment 4>
Next, Embodiment 4 of the present invention will be described with reference to FIG. In the present embodiment, a diffusion plate 15C used in the lighting device according to the fourth embodiment is illustrated. FIG. 11 is a plan view of a diffusion plate 15 </ b> C used in the lighting device according to the fourth embodiment. The basic configuration of the illumination device of this embodiment is the same as that of the first embodiment. However, in the lighting device of the present embodiment, the number of LEDs 17 distributed on the bottom plate 14a of the chassis 14 is set larger than that of the first embodiment. Further, the illumination device of the present embodiment does not include the diffusing lens 19 as in the first embodiment. And in the illuminating device of this embodiment, the shape of the low light transmission area | region part 51C formed on the back surface 115b of the diffusion plate 15C differs from the thing of Embodiment 1. FIG.

As shown in FIG. 11, the low light transmission region portion 51 </ b> C formed in the diffusion plate 15 </ b> C of the present embodiment has a substantially square shape (square shape). In the case of this embodiment, since the shape of the LED 17 viewed from the front side is a substantially square shape (square shape), the shape of the light transmission region 51C is also set to a similar shape. The low light transmission region portions 51C provided on the diffusion plate 15C are arranged in a matrix corresponding to the LEDs 17 distributed on the bottom plate 14a of the chassis 14 in a matrix. As in the first embodiment, on the plate surface of the diffusion plate 15C (plate-like base material 115), a region other than the low light transmission region 51C is a high light transmission region 52C. The alignment part 53 of this embodiment is formed on the front plate surface 115a of the plate-like substrate 115 by printing, as in the first embodiment.

Thus, according to the shape and arrangement state of the light source (LED) 17 of the illumination device, the shape and arrangement state of the low light transmission region 51C formed on the diffusion plate 15C may be set.

<Embodiment 5>
Next, Embodiment 5 of the present invention will be described with reference to FIG. In the present embodiment, a diffusion plate 15D used in the lighting device according to the fifth embodiment is illustrated. FIG. 12 is an enlarged view of a diffusion plate 15D used in the lighting apparatus according to the fifth embodiment. The basic configuration of the illumination device of the present embodiment is the same as that of the first embodiment. However, the configuration of the diffusion plate 15D is different from that of the first embodiment. Specifically, the low light transmission region portion 51D and the high light transmission region portion 52D formed on the back surface 115b of the diffusion plate 15D are formed from a dot-printed pattern, as in the first embodiment. Is different.

In the diffusion plate 15D of the present embodiment, a paste-like white paint containing a metal oxide such as titanium oxide is printed in a dot pattern on the back surface 115b of the plate-like substrate 115, and the low light transmission region portion 51D and A high light transmission region 52D is formed. One low light transmission region 51 is formed by collecting a plurality of dots (points) 151 (151a) in a circular shape. In addition, the arrangement | positioning location of the low light transmission area | region part 51D respond | corresponds to the arrangement pattern of LED17 like Embodiment 1, and is set on the back surface 115b of light-guide plate 15D (plate-shaped base material 115) in the matrix form. Yes. The high light transmission region portion 52D includes a region other than the low light transmission region portion 51D on the plate surface of the diffusion plate 15D. In the present embodiment, the paint dots 151b are also formed at predetermined intervals in the high light transmission region 52D. Each dot 151a forming the low light transmission region 51D and each dot 151b formed in the high light transmission region 51D are formed from the paint having the same concentration (the concentration of the metal oxide contained in the paint). Has been. Similar to the first embodiment, the diffusion plate 15D of the present embodiment is provided with an alignment portion 53 at a predetermined location on the front plate surface 115a.

As in the present embodiment, the low light transmission region 51D and the high light transmission region 52D of the diffusion plate 15D may be formed by a dot pattern. By using the dot pattern in this way, it becomes easy to adjust the light transmittance of the low light transmission region portion 51D and the high light transmission region portion 52D. For example, when it is desired to increase the light transmittance of the high light transmission region 52D, the dot 151a formed in the high light transmission region 52D may be designed to be reduced. On the other hand, when it is desired to reduce the light transmittance of the high light transmission region 52D, the number of dots 151a formed in the high light transmission region 52D may be increased. Further, the low light transmission region 51D may be designed to reduce some dots 151b forming the low light transmission region 51D when it is desired to increase the transmittance of the low light transmission region 51D.

Also, the illumination device including the diffusion plate 15D of the present embodiment can emit light that spreads substantially uniformly in a plane toward the liquid crystal panel 11 as in the first embodiment.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the first embodiment, the alignment portion 53 is formed on the front plate surface 115a of the diffusion plate 15a. However, in another embodiment, for example, on the plate surface 115b on the back side of the diffusion plate 15a. An alignment portion 53 may be formed.

(2) In the first embodiment, the alignment portion 53 is substantially L-shaped. However, in other embodiments, the alignment portions intersect each other vertically, for example, and each of the receiving plate portions 14d. It may have a shape (so-called cross shape) along the inner edge portion 114.

(3) In the second embodiment, the alignment portion 53A is formed by a notch (hole) that penetrates the diffusion plate 15A in the thickness direction. However, in other embodiments, for example, the alignment portion May consist of grooves formed in the front plate surface 115a of the diffusion plate 15A.

(4) In the first embodiment, the low light transmission region 51 is formed on the plate surface 115b on the back side of the diffusion plate 15a by printing. In other embodiments, the front plate of the diffusion plate 15 is used. The low light transmission region 51 may be formed on the surface 115a.

(5) In the first embodiment, the predetermined coating film is printed only on the low light transmission region 51 on the plate surface 115b on the back side of the diffusion plate 15a. However, in other embodiments, the high light transmission is performed. A predetermined coating film may also be printed on the region 52. However, in this case, the concentration of the coating applied to form the low light transmission region 51 (the concentration of the metal oxide such as titanium oxide contained in the coating) is applied to the high light transmission region 52. It is set higher than the concentration of paint. For example, a low-concentration coating material is applied (printed) on the entire plate surface 115b of the plate-like substrate 115 constituting the diffusion plate 15a, and then a high-concentration coating material is applied to a predetermined location on the plate surface 115b. Each low light transmission region 51 may be formed by application (printing).

(6) Although the TFT is used as the switching element of the liquid crystal display device in the above embodiment, the present invention can also be applied to a liquid crystal display device using a switching element other than the TFT (for example, a thin film diode).

(7) In the above embodiment, the liquid crystal display device performs color display, but the present invention can also be applied to a liquid crystal display device that performs black and white display.

(8) In the above embodiment, a liquid crystal display device using a liquid crystal panel as the display panel has been illustrated, but the present invention is also applicable to a display device using another type of display panel.

(9) In the above embodiment, the television receiver provided with the tuner is exemplified, but the present invention is also applicable to a display device not provided with the tuner.

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel (display panel), 12 ... Illumination device (backlight device), 13 ... Frame, 14 ... Chassis, 14a ... Bottom plate, 14c ... Side plate (wall plate), 14d DESCRIPTION OF SYMBOLS ... Base plate (support), 15 ... Optical member, 15a ... Diffusing plate, 15b ... Optical sheet, 16 ... Frame, 17 ... Light source (LED), 18 ... Light source substrate (LED substrate), 19 ... Diffusing lens, 20 ... Fixing member, 21 ... reflective sheet, 22 ... support member, 51 ... low light transmission region, 52 ... high light transmission region, 53 ... positioning portion

Claims

A chassis having a bottom plate and a wall plate rising from a peripheral edge of the bottom plate, a plurality of light sources arranged on the bottom plate, each emitting light in a direction rising from the bottom plate, and so as to cover the light source A plurality of low-light-transmitting region portions that are arranged and are made of a plate-like member that allows light from the light source to be transmitted while diffusing, each of which is arranged so as to overlap the light source and have relatively low light transmittance And a diffusing plate comprising a portion other than the low light transmission region portion and having a high light transmission region portion having relatively high light transmittance.
The chassis has a support base that is provided at the upper end of the wall plate and is configured in a frame shape surrounding the bottom plate to support the diffusion plate,
The diffusion plate is arranged so as to cover the light source in a state where a peripheral portion is supported by the support base, and the low light transmission region portion is disposed on the light source so that the low light transmission region portion overlaps the light source. The illuminating device according to claim 1, further comprising an alignment portion for aligning with respect to.
The illuminating device according to claim 2, wherein the alignment unit is provided at a predetermined position of the diffusion plate that overlaps with an inner edge of the support when the low light transmission region overlaps the light source.
The lighting device according to claim 3, wherein the alignment portion has a shape along an inner edge portion of the support base.
The illuminating device according to any one of claims 2 to 4, wherein the alignment portion is formed of a coating film formed on a front plate surface of the peripheral portion of the diffusion plate.
The lighting device according to any one of claims 2 to 4, wherein the alignment portion is formed by cutting out the peripheral portion of the diffusion plate.
The diffusion plate has a rectangular shape,
The lighting device according to claim 2, wherein the alignment unit is provided at a diagonal of the diffusion plate.
The lighting device according to any one of claims 1 to 7, wherein the light source is an LED.
The lighting device according to any one of claims 1 to 8,
A display panel that displays an image using light from the illumination device.
The display device according to claim 9, wherein the display panel is a liquid crystal panel in which liquid crystal is sealed between a pair of substrates.
A television receiver comprising the display device according to claim 9 or 10.