WO2013005708A1

WO2013005708A1 - Illumination device, display device, and television reception device

Info

Publication number: WO2013005708A1
Application number: PCT/JP2012/066849
Authority: WO
Inventors: 良武石元
Original assignee: シャープ株式会社
Priority date: 2011-07-07
Filing date: 2012-07-02
Publication date: 2013-01-10

Abstract

This backlight device is provided with: an LED (17); a light guide plate (19) having a light exit surface (19a) and a light entrance surface (19b) disposed facing the LED (17); an LED substrate (18) having an LED mounting section (18a) to which the LED (17) is mounted and a radiator plate section (18b) extending from the LED mounting section (18a) towards the light guide plate (19) side; a chassis (14) that houses the LED substrate (18) and the light guide plate (19) and that has a bottom plate (14a) parallel to the plate surface of the light guide plate (19) and sandwiching the radiator plate section (18b) with respect to the light guide plate (19); and a positioning structure (23) that, by means of being formed at the radiator plate section (18b) and the light guide plate (19), causing the fitting together thereof by means of a protrusion/recession, positions the LED substrate (18) and the light guide plate (19) at least with respect to the direction from the LED (17) towards the light entrance surface (19b).

Description

Lighting device, display device, and television receiver

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

In recent years, the display elements of image display devices such as television receivers are shifting from conventional cathode ray tubes to thin display panels such as liquid crystal panels and plasma display panels, which enables thinning of image display devices. Since the liquid crystal panel used for the liquid crystal display device does not emit light by itself, a backlight device is separately required as a lighting device, and the backlight device is roughly classified into a direct type and an edge light type according to the mechanism. In order to further reduce the thickness of the liquid crystal display device, it is preferable to use an edge light type backlight device, and an example described in Patent Document 1 below is known.

JP 2010-276628 A

(Problems to be solved by the invention)
In what is described in Patent Document 1 described above, a cut-and-raised piece is formed in the chassis constituting the backlight device, and a light source substrate on which a light source is mounted is attached to the cut-and-raised piece. Then, a convex portion is formed on the light guide plate, and the convex portion is cut and raised and fixed in contact with the piece.

However, in the above configuration, in addition to the error in assembling the light source substrate with respect to the cut and raised pieces, an error in assembling the light guide plate with respect to the cut and raised pieces may also occur. The relationship is easy to vary, and the positioning accuracy is low. The light guide plate is provided with a light incident surface facing the light source and receiving light from the light source. If the distance between the light incident surface and the light source varies, the light incident efficiency varies. At the same time, since the luminance of the emitted light varies, the display quality may be deteriorated.

The present invention has been completed based on the above circumstances, and an object thereof is to obtain high positioning accuracy.

(Means for solving the problem)
The illumination device of the present invention includes a light source, a light guide plate that is arranged to face the light source and receives a light incident surface on which light from the light source is incident, and a light emitting surface that emits the incident light. A light source substrate having a light source mounting portion on which a light source is mounted and a heat radiating plate portion extending from the light source mounting portion toward the light guide plate, and the light source substrate and the light guide plate, By forming a chassis parallel to the plate surface of the light guide plate and having a bottom plate that sandwiches the heat radiating plate portion between the light guide plate and the heat radiating plate portion and the light guide plate, respectively, and engaging with each other in an uneven manner. And a positioning structure that positions the light source substrate and the light guide plate at least in a direction from the light source toward the light incident surface.

In this way, the light emitted from the light source is incident on the light incident surface of the light guide plate arranged opposite to the light source, and is then propagated through the light guide plate and then emitted from the light exit surface. Since the heat radiating plate portion constituting the light source substrate extends from the light source mounting portion toward the light guide plate side and is sandwiched between the light guide plate and the bottom plate of the chassis, the heat radiating plate portion is temporarily guided from the light source mounting portion. Compared to a case where the light source is extended toward the side opposite to the light plate side, it is preferable in reducing the size of the lighting device. Further, the heat generated from the light source by the heat radiating plate portion can be efficiently transmitted to the bottom plate of the chassis via the light source mounting portion.

And since the light source substrate and the light guide plate are directly positioned at least in the direction from the light source to the light incident surface by the positioning structure that is formed on the heat dissipation plate portion and the light guide plate, respectively, and is fitted to the concave and convex portions, Compared to the conventional configuration in which the light source board and light guide plate are positioned indirectly via a part of the chassis, the effect of assembly errors is reduced by the amount of inclusions, so positioning Such accuracy is higher. This makes it difficult for variations in the incident efficiency of light incident on the light incident surface from the light source and the luminance of the emitted light from the light emitting surface of the light guide plate, thereby stabilizing the light utilization efficiency and the luminance of the emitted light. be able to. In addition, since the positioning structure is provided by using the heat radiating plate portion extending from the light source mounting portion to the light guide plate side of the light source substrate, it is temporarily directed to the light guide plate side separately from the heat radiating plate portion. Compared to the case where an extending structure is provided and a positioning structure is provided there, it is preferable for simplifying the entire structure.

The following configuration is preferable as an embodiment of the present invention.
(1) The positioning structure includes a positioning concave portion formed on a surface of the light guide plate facing the heat radiating plate portion, a positioning concave portion formed on the heat radiating plate portion and protruding toward the light guide plate. It is comprised from the positioning convex-shaped part fitted by the part. If it does in this way, since it can be set as the structure by which a protrusion is not formed in the board surface facing the heat sink part in a light-guide plate, it is excellent in the handleability of a light-guide plate. In addition, although the light source substrate is provided with the light source mounting portion and the light source in the first place, although the positioning convex portion is formed on the heat radiating plate portion, the presence of the positioning convex portion immediately improves the handleability of the light source substrate. It is less likely to cause damage.

(2) An optical member arranged opposite to the light exit surface of the light guide plate is provided, and the positioning concave portion is configured to penetrate the light guide plate in the plate thickness direction. On the other hand, the optical member is formed with a second positioning concave portion into which the positioning convex portion is fitted. In this way, the positioning convex portion passing through the positioning concave portion formed in the light guide plate is fitted to the second positioning concave portion formed in the optical member, so that the optical member together with the light guide plate is also used. Positioning can be achieved.

(3) The light source side end portion of the optical member is provided with a light shielding portion that protrudes toward the light source side and is disposed closer to the light source side than the light incident surface and blocks light from the light source. ing. In this way, the light emitted from the light source is blocked by the light shielding portion, so that, for example, it directly enters the end of the optical member on the light source side or in a gap that may be generated between the light guide plate and the optical member. It is prevented from entering. Thereby, it can prevent that the light from a light source radiate | emits outside, without entering into the light-incidence surface of a light-guide plate. Here, when the positioning convex portion is fitted to the second positioning concave portion, the light source mounted on the light source substrate and the light shielding portion provided on the optical member are highly accurate in the direction from the light source toward the light incident surface. Therefore, since the positioning is performed, the light shielding performance by the above-described light shielding portion can be stably exhibited.

(4) The light shielding portion has light reflectivity for reflecting light. If it does in this way, the light from a light source can be reflected by the light-shielding part, and can be made to go to a light-incidence surface. Thereby, the utilization efficiency of light can be improved.

(5) The second positioning concave portion has a hole shape penetrating the optical member in the thickness direction, and the hole edge is supported in the vertical direction by the positioning convex portion. In this way, when the positioning convex portion is fitted to the second positioning concave portion, the hole edge of the second positioning concave portion is supported in the vertical direction by the positioning convex portion. In other words, since the optical member can be suspended and supported by the positioning convex portion, for example, even when the optical member is thermally expanded or contracted, deformation such as wrinkles or deflection is caused by the weight of the optical member itself. Is unlikely to occur. Accordingly, luminance unevenness can be more effectively suppressed.

(6) The positioning structure is arranged at a position that does not overlap the light source in a direction from the light source toward the light incident surface. In this way, light incident on the light incident surface of the light guide plate from the light source is less likely to hit the positioning structure, so that unevenness due to the positioning structure is less likely to occur in the emitted light from the light exit surface.

(7) A plurality of the light sources are intermittently arranged along the light incident surface, and the positioning structure is closer to the end than the light source arranged at the end in the arrangement direction of the light sources. It is arranged at a position shifted to. In this way, it is possible to further reduce the unevenness of the emitted light caused by the positioning structure, as compared with the case where the positioning structure is arranged between adjacent light sources.

(8) The light source substrates are arranged in a pair with the light guide plate interposed therebetween, whereas the light guide plates are opposed to the light sources mounted on the pair of light source substrates. A pair of the light incident surfaces is provided, and the positioning structure is provided on each of the heat radiating plate portions and the light guide plate of the pair of light source substrates. In this way, since each heat radiating plate part and the light guide plate of the pair of light source substrates arranged so as to sandwich the light guide plate are positioned relative to each other by the positioning structure provided respectively, Incidence efficiencies of light incident on the respective light incident surfaces facing each other from the mounted light sources are difficult to vary. Therefore, the brightness of the light emitted from the light exit surface is less likely to be uneven.

(9) Whereas the light source mounting portion rises from the heat radiating plate portion and is arranged to face the light incident surface, the light source is positioned on the opposite side of the mounting surface with respect to the light source mounting portion. It consists of a top-emitting LED whose surface is the light emitting surface. In this way, since the top light emitting type LED is provided as the light source in the light source mounting portion that stands up from the heat radiating plate and faces the light incident surface, the rising direction of the heat radiating plate portion The degree of freedom of LED arrangement is increased. Thereby, it becomes possible to arrange | position LED in the suitable position where the incident efficiency of light becomes favorable with respect to the light-incidence surface of a light-guide plate.

(10) Whereas the light source mounting portion is configured to extend along the heat radiating plate portion, the light source has side light emission in which a side surface adjacent to the mounting surface with respect to the light source mounting portion is a light emitting surface. It consists of a type of LED. In this way, since the side light emitting type LED is provided as the light source in the light source mounting portion that is configured to extend along the heat radiating plate portion, it is suitable for using a thin light guide plate, Therefore, it is also suitable for reducing the thickness of the entire lighting device.

Next, in order to solve the above problem, a display device of the present invention includes the above-described illumination device and a display panel that performs display using light from the illumination device.

According to such a display device, the illumination device that supplies light to the display panel has high positioning accuracy between the light source substrate and the light guide plate, and the brightness of the emitted light is stable. It is possible to realize display with excellent display quality.

A liquid crystal panel can be exemplified as the display panel. Such a display device can be applied as a liquid crystal display device to various uses such as a display of a television or a personal computer, and is particularly suitable for a large screen.

(The invention's effect)
According to the present invention, high positioning accuracy can be obtained.

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 The top view which shows arrangement | positioning structure of the chassis in the backlight apparatus with which a liquid crystal display device is equipped, a light-guide plate, and an LED board. Sectional view taken along line iv-iv in FIG. V-v sectional view of FIG. Sectional view along line vi-vi in FIG. The top view which shows the arrangement configuration of a chassis and an LED board Bottom view of light guide plate Sectional drawing which shows the cross-sectional structure of LED which concerns on Embodiment 2 of this invention, and an LED board. The top view which shows the arrangement structure of the optical member and LED board which have the chassis which concerns on Embodiment 3 of this invention, and a light-shielding part. Xi-xi sectional view of FIG. The top view which shows the arrangement configuration of the chassis which concerns on Embodiment 4 of this invention, a light-guide plate, and an LED board. The top view which shows the arrangement configuration of the chassis which concerns on Embodiment 5 of this invention, a light-guide plate, and an LED board. The top view which shows the arrangement configuration of the chassis which concerns on Embodiment 6 of this invention, a light-guide plate, and an LED board. The top view which shows the arrangement configuration of the chassis which concerns on Embodiment 7, the optical member which has a light-shielding part, and an LED board. Xvi-xvi sectional view of FIG.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the liquid crystal display device 10 is illustrated. In addition, a part of each drawing shows an X axis, a Y axis, and a Z axis, and each axis direction is drawn to be a direction shown in each drawing. Among these, the Y-axis direction coincides with the vertical direction, and the X-axis direction coincides with the horizontal direction. In addition, unless otherwise noted, the vertical direction is used as a reference for upper and lower descriptions. Moreover, let the upper side shown in FIGS. 4-6 be a front side, and let the lower side of the figure be a back side.

As shown in FIG. 1, the television receiver TV according to the present embodiment includes a liquid crystal display device 10, front and back cabinets Ca and Cb that are accommodated so as to sandwich the liquid crystal display device 10, a power source P, a tuner T, The liquid crystal display device 10 is supported by the stand S in a state where the display surface of the liquid crystal display device 10 is along the vertical direction (Y-axis direction). The liquid crystal display device (display device) 10 has a horizontally long rectangular shape (rectangular shape, longitudinal shape) as a whole, and is accommodated in a vertically placed state. As shown in FIG. 2, the liquid crystal display device 10 includes a liquid crystal panel 11 that is a display panel and a backlight device (illumination device) 12 that is an external light source, which are integrated by a frame-like bezel 13 or the like. Is supposed to be retained. Note that “the display surface of the liquid crystal display device 10 is along the vertical direction” as referred to in the present embodiment is not limited to an aspect in which the display surface of the liquid crystal display device 10 is parallel to the vertical direction, but from a direction along the horizontal direction. Also, it means that it is installed in a direction relatively along the vertical direction, and includes, for example, those inclined by 0 ° to 45 °, preferably 0 ° to 30 ° with respect to the vertical direction.

As shown in FIG. 2, the liquid crystal panel 11 has a horizontally long rectangular shape (rectangular shape, longitudinal shape) in a plan view, and a pair of glass substrates having excellent translucency are separated by a predetermined gap. In addition, the liquid crystal is sealed between both substrates. One substrate is provided with a switching element (for example, TFT) connected to a source wiring and a gate wiring orthogonal to each other, a pixel electrode connected to the switching element, an alignment film, and the like. Are provided with a color filter in which colored portions such as R (red), G (green), and B (blue) are arranged in a predetermined arrangement, a counter electrode, and an alignment film. As shown in FIG. 3, the liquid crystal panel 11 has a display area AA on the center side of the screen where an image can be displayed and a frame shape (frame shape) surrounding the display area AA on the outer peripheral edge side of the screen. It is divided into a non-display area NAA. In FIG. 3, the inner area surrounded by the alternate long and short dash line indicates the display area AA, and the outer area indicates the non-display area NAA. A polarizing plate is disposed on the outside of both substrates.

As shown in FIG. 2, the backlight device 12 includes a chassis 14 having a substantially box shape having a light emitting portion 14 c that opens toward the front side (light emitting side, liquid crystal panel 11 side), and light emitting from the chassis 14. And an optical member 15 arranged to cover the portion 14c. Furthermore, in the chassis 14, an LED (Light Emitting Diode) 17 that is a light source, an LED substrate 18 on which the LED 17 is mounted, and light from the LED 17 are guided to the optical member 15 (liquid crystal panel 11). And a frame (pressing member) 16 for pressing the light guide plate 19 and the optical member 15 from the front side. The backlight device 12 includes LED substrates 18 having LEDs 17 at both ends on the short side thereof, and a light guide plate 19 disposed at the center between the LED substrates 18 on both sides. The so-called edge light type (side light type) is used. Below, each component of the backlight apparatus 12 is demonstrated in detail.

The chassis 14 is made of, for example, a metal plate such as an aluminum plate or an electrogalvanized steel plate (SECC), and as shown in FIGS. It consists of a side plate 14b that rises one by one from each outer end on the long side and the short side in 14a. The long side direction of the chassis 14 (bottom plate 14a) coincides with the X-axis direction (horizontal direction), and the short side direction coincides with the Y-axis direction (vertical direction). Further, the frame 16 and the bezel 13 can be screwed to the side plate 14b.

As shown in FIG. 2, the optical member 15 has a horizontally long rectangular shape when viewed in a plane, like the liquid crystal panel 11 and the chassis 14. The optical member 15 is placed on the front side (light emitting side) of the light guide plate 19 and is interposed between the liquid crystal panel 11 and the light guide plate 19. 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 diffusing plate 15a has a structure in which a large number of diffusing particles are dispersed in a base material made of a substantially transparent synthetic resin having a predetermined thickness and has a function of diffusing transmitted light. The optical sheet 15b has a sheet shape that is thinner than the diffusion plate 15a, and two optical sheets 15b are laminated. Specific types of the optical sheet 15b include, for example, a diffusion sheet, a lens sheet, a reflective polarizing sheet, and the like, which can be appropriately selected and used.

As shown in FIG. 2, the frame 16 is formed in a frame shape (frame shape) extending along the outer peripheral edge portions of the optical member 15 and the light guide plate 19, and the outer peripheral edge of the optical member 15 and the light guide plate 19. It can be pressed from the front side over almost the entire circumference while facing the part. The frame 16 is made of a synthetic resin and has a light shielding property by having a surface with, for example, a black color. As shown in FIG. 4, a first reflection sheet 20 for reflecting light is attached to the back surface of both short sides of the frame 16, that is, the surface facing the light guide plate 19 and the LED substrate 18 (LED 17). It has been. The first reflection sheet 20 has a size extending over almost the entire length of the short side portion of the frame 16, and covers the LED 17 side end portion and LED 17 group of the light guide plate 19 from the front side collectively. Is done. Further, the frame 16 can receive the outer peripheral edge of the liquid crystal panel 11 from the back side.

3 and 4, 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 mounted on the substrate unit has one main emission wavelength, and specifically, one that emits blue light in a single color is used. On the other hand, the resin material that seals the LED chip is dispersed and blended with a phosphor that emits a predetermined color when excited by the blue light emitted from the LED chip, and generally emits white light as a whole. It is said. In addition, as the phosphor, for example, a yellow phosphor that emits yellow light, a green phosphor that emits green light, and a red phosphor that emits red light are used in appropriate combination, or any one of them is used. It can be used alone. This LED 17 is of a so-called top surface light emitting type in which the top surface opposite to the mounting surface with respect to the LED substrate 18 is the light emitting surface 17a.

As shown in FIGS. 2, 3, and 7, a pair of LED boards 18 sandwich the light guide plate 19 from both sides in the long side direction (X-axis direction), and the pair of LED boards 18 are at both ends of the short side of the chassis 14. Each is arranged. As shown in FIG. 4, the LED board 18 is composed of an LED mounting portion 18a on which the LED 17 is mounted, and a heat radiating plate portion 18b extending from the LED mounting portion 18a toward the light guide plate 19 side. The mounting portion 18a and the heat radiating plate portion 18b are connected to each other in such a manner that their plate surfaces are orthogonal to each other, thereby forming a substantially L-shaped cross section as a whole. Specifically, the LED board 18 has a posture in which the plate surface of the LED mounting portion 18 a is parallel to the Y-axis direction and the Z-axis direction, that is, the side plate 14 b on the short side of the chassis 14 and the light incident surface 19 b of the light guide plate 19. The posture of the heat radiating plate portion 18b is parallel to the X-axis direction and the Y-axis direction, that is, the chassis. 14 is accommodated in the chassis 14 while being in a posture parallel to the plate surfaces of the bottom plate 14 a and the light guide plate 19 (orientation perpendicular to the side plates 14 b of the chassis 14 and the light incident surface 19 b of the light guide plate 19). In a state where the LED board 18 is accommodated in the chassis 14, the LED mounting portion 18 a is directed to the inner surface of the side plate 14 b on the short side of the chassis 14 and has a predetermined interval with respect to the light incident surface 19 b of the light guide plate 19. The heat dissipation plate portion 18b is directed to the inner surface of the bottom plate 14a of the chassis 14 and is located between the bottom plate 14a on the back side and the light guide plate 19 (light guide reflection sheet 22) on the front side. Sandwiched between. The heat generated from each LED 17 by the heat radiating plate portion 18b can be efficiently transmitted to the bottom plate 14a of the chassis 14 to radiate heat.

More specifically, as shown in FIG. 4, the LED mounting portion 18a is substantially perpendicular to the side plate 14b from the end opposite to the light guide plate 19 side of the heat radiating plate portion 18b parallel to the bottom plate 14a of the chassis 14. Standing up to. On the other hand, the heat radiating plate portion 18b extends from the end of the LED mounting portion 18a opposite to the frame 16 side (bottom plate 14a side) toward the light guide plate 19 side, and the end portion of the light guide plate 19 on the LED 17 side. Support from the back side. Therefore, the light guide plate 19 is slightly supported from the bottom plate 14a of the chassis 14 by supporting both ends on the short side, that is, both ends on the LED 17 side, from the back side by the heat radiating plate portions 18b of the pair of LED substrates 18, respectively. It is kept in a floating position. In addition, the dimensions in the Y-axis direction of the LED mounting portion 18a and the heat radiating plate portion 18b are substantially the same as each other as shown in FIGS. It is said. The extension dimension in the X-axis direction from the LED mounting portion 18a in the heat radiating plate portion 18b is larger than the width dimension in the short side portion of the frame 16 and the width dimension of the second reflection sheet 21 described later.

The surface of the LED mounting portion 18a facing the light guide plate 19 (the surface facing the light incident surface 19b) is surface-mounted with the LED 17 having the above-described configuration as shown in FIGS. The mounting surface. A plurality of LEDs 17 are arranged in a line (linearly) in parallel on the mounting surface of the LED mounting portion 18a along the length direction (Y-axis direction) with a predetermined interval. That is, it can be said that a plurality of LEDs 17 are intermittently arranged in parallel along the short side direction at both ends on the short side of the backlight device 12. The interval between the LEDs 17 adjacent to each other in the Y-axis direction, that is, the arrangement pitch of the LEDs 17 is substantially equal. Note that the arrangement direction of the LEDs 17 coincides with the length direction (Y-axis direction) of the LED mounting portion 18a and the light incident surface 19b. Further, on the mounting surface of the LED mounting portion 18a, a wiring pattern (not shown) made of a metal film (not shown) extends in the Y-axis direction and connects the adjacent LEDs 17 in series across the LED 17 group. And the terminal portions formed at both ends of the wiring pattern are connected to an external LED driving circuit, so that driving power can be supplied to each LED 17. As shown in FIGS. 3 and 7, the pair of LED substrates 18 are housed in the chassis 14 in such a manner that the LED mounting portions 18a face each other, so that each LED 17 mounted on each of the LED mounting portions 18a. The light emitting surfaces 17a are opposed to each other, and the optical axes of the LEDs 17 substantially coincide with the X-axis direction. In other words, the LEDs 17 mounted on the LED mounting portions 18 a of the pair of LED substrates 18 are respectively arranged in opposed relation to both end portions on the short side of the light guide plate 19. Further, the LED board 18 is made of metal (for example, aluminum) similarly to the chassis 14, and the wiring pattern (not shown) described above is formed on the surface of the LED mounting portion 18 a via an insulating layer. ing. In addition, as a material used for the base material of LED board 18, insulating materials, such as a ceramic, can also be used.

The light guide plate 19 is made of a synthetic resin material (for example, acrylic resin such as PMMA or polycarbonate) having a refractive index sufficiently higher than air and substantially transparent (excellent translucency). As shown in FIGS. 2, 3, and 8, the light guide plate 19 has a horizontally long rectangular shape in plan view and is thicker than the optical member 15 as in the case of the liquid crystal panel 11 and the chassis 14. In the main surface (plate surface), the long side direction coincides with the X-axis direction, the short side direction coincides with the Y-axis direction, and the plate thickness direction perpendicular to the main surface coincides with the Z-axis direction. . As shown in FIG. 4, the light guide plate 19 is disposed in the chassis 14 at a position directly below the liquid crystal panel 11 and the optical member 15, and forms a pair of LED substrates disposed at both ends on the short side of the chassis 14. 18 are arranged so as to be sandwiched between 18 in the X-axis direction. Therefore, while the alignment direction of the LED 17 (LED mounting portion 18a) and the light guide plate 19 coincides with the X-axis direction, the alignment direction of the optical member 15 (liquid crystal panel 11) and the light guide plate 19 is the Z-axis direction. It is in agreement and both arrangement directions are orthogonal to each other. The light guide plate 19 has a function of introducing the light emitted from the LED 17 in the X-axis direction and raising and emitting the light toward the optical member 15 side (front side) while propagating the light inside. .

As shown in FIGS. 3 and 8, the light guide plate 19 has a substantially flat plate shape extending along the bottom plate 14a of the chassis 14 and the main surfaces (each plate surface) of the optical member 15. Are parallel to the X-axis direction and the Y-axis direction. Of the main surface of the light guide plate 19, the surface facing the front side (the surface facing the optical member 15) is a light emitting surface 19 a that emits internal light toward the optical member 15 and the liquid crystal panel 11. Outer peripheral end surfaces adjacent to the main surface of the light guide plate 19, both end surfaces on the short side that are long along the Y-axis direction are opposed to the LEDs 17 (LED mounting portions 18 a) with a predetermined space therebetween. These form a pair of light incident surfaces 19b on which the light emitted from the LEDs 17 is incident. On the front side of the space held between the LED 17 and the light incident surface 19b, as shown in FIG. 4, the first reflection sheet 20 described above is arranged, whereas on the back side of the space, A second reflection sheet 21 is disposed so as to sandwich the same space with the first reflection sheet 20. Thereby, the light from LED17 can be made to inject efficiently with respect to the light-incidence surface 19b by repeatedly reflecting between both the

reflective sheets

20 and 21. FIG. Each light incident surface 19b is a surface parallel to the Y-axis direction (the LED 17 arrangement direction) and the Z-axis direction, that is, the mounting surface of the LED mounting portion 18a, and is substantially orthogonal to the light emitting surface 19a. The surface Further, the alignment direction of the LED 17 and the light incident surface 19b coincides with the X-axis direction and is parallel to the light emitting surface 19a.

As shown in FIG. 4, the light guide plate 19 propagates through the back side of the light guide plate 19, that is, the bottom surface (the surface facing the bottom plate 14a of the chassis 14) 19c, which is the opposite side of the light emitting surface 19a. A light guide reflection sheet 22 that can reflect the light reaching the bottom surface 19c and rise up toward the front side, that is, the light emitting surface 19a side, is provided so as to cover almost the entire area. In other words, the light guide reflection sheet 22 is disposed between the bottom plate 14 a of the chassis 14 and the light guide plate 19. Note that at least one of the light exit surface 19a of the light guide plate 19 and the bottom surface 19c on the opposite side thereof has a reflection portion (not shown) or an internal portion that reflects the internal light and prompts the light exit from the light exit surface 19a. The scattering part (not shown) that scatters the light of the light and promotes the light output from the light output surface 19a is patterned so as to have a predetermined in-plane distribution, so that the light emitted from the light output surface 19a is in-plane It is controlled to have a uniform distribution.

Now, the LED substrate 18 and the light guide plate 19 according to the present embodiment are respectively provided with positioning structures 23 capable of positioning each other by engaging with each other as shown in FIGS. ing. The positioning structure 23 is opposed to the positioning convex portion 23 a formed on the heat radiating plate portion 18 b extending along the bottom plate 14 a of the chassis 14 in the LED substrate 18 and the heat radiating plate portion 18 b in the light guide plate 19. The positioning concave portion 23b is formed on the bottom surface 19c. A pair of positioning structures 23 each including a pair of positioning convex portions 23 a and positioning concave portions 23 b are arranged at two positions separated from each other in the X-axis direction within the bottom surface 19 c of the light guide plate 19. The pair of positioning structures 23 are arranged in the vicinity of the upper end portion in the vertical direction of the light guide plate 19 in the Y-axis direction, and are arranged at substantially the same position.

As shown in FIGS. 5 to 7, one positioning convex portion 23 a is formed on each heat radiating plate portion 18 b of the pair of LED substrates 18. The positioning convex portion 23a protrudes from the surface of the heat radiating plate portion 18b facing the light guide plate 19 to the front side, that is, toward the light guide plate 19 side, and is integrally formed with the heat radiating plate portion 18b. . The positioning convex portion 23a is made of a substantially rectangular block-like protrusion that is horizontally long when viewed in a plane, and the long side direction thereof coincides with the X-axis direction and the short side direction thereof coincides with the Y-axis direction. . The outer surfaces of the four sides constituting the outer peripheral surface of the positioning convex portion 23a are flat surfaces in which both outer surfaces on the long side are parallel to the X-axis direction and both outer surfaces on the short side are parallel to the Y-axis direction. The positioning convex portion 23a is arranged in the vicinity of the extending tip portion from the LED mounting portion 18a in the heat radiating plate portion 18b in the X-axis direction (position slightly closer to the extending proximal end than the extending tip position), The Y-axis direction is arranged near the upper end portion in the vertical direction (a position slightly below the upper end position in the vertical direction).

As shown in FIGS. 5, 6 and 8, a pair of positioning concave portions 23 b are formed on the light guide plate 19. The positioning concave portion 23b is formed by partially denting the bottom surface 19c of the light guide plate 19 facing the heat radiating plate portion 18b, and is open only toward the back side of the light guide plate 19. It has a concave shape that does not penetrate 19 in the thickness direction. The positioning concave portion 23b has a substantially rectangular shape that is horizontally long when viewed in a plane, and the long side direction thereof coincides with the X-axis direction, and the short side direction thereof coincides with the Y-axis direction. The inner surfaces of the four sides constituting the inner peripheral surface of the positioning concave portion 23b are flat surfaces in which both inner surfaces on the long side are parallel to the X-axis direction and both inner surfaces on the short side are parallel to the Y-axis direction. The pair of positioning concave portions 23b are disposed at two positions spaced apart in the X-axis direction on the light guide plate 19, and more specifically, are disposed closer to the LED 17 side end than the central portion in the X-axis direction. ing. In addition, the pair of positioning concave portions 23b are arranged at the upper end portion in the vertical direction of the light guide plate 19 in the Y-axis direction (a position slightly lower than the upper end position in the vertical direction).

As the positioning convex portion 23a and the positioning concave portion 23b constituting the positioning structure 23 are unevenly fitted, the inner and outer peripheral surfaces of each other are brought into contact with each other as shown in FIGS. Thus, the LED substrate 18 and the light guide plate 19 can be positioned in both the X-axis direction and the Y-axis direction. Since the pair of positioning structures 23 are arranged at the upper end portion in the vertical direction of the light guide plate 19, the light guide plate 19 is configured so that the liquid crystal display device 10 has a posture in which the display surface of the liquid crystal panel 11 is along the vertical direction. Further, the positioning structure 23 is supported in a state suspended from the upper side in the vertical direction.

Here, the detailed arrangement of the positioning structure 23 will be described. As shown in FIG. 3, the positioning structure 23 overlaps the LED 17 in a position shifted from the LED 17 in the Y-axis direction (LED 17 arrangement direction), in other words, in the X-axis direction (direction from the LED 17 toward the light incident surface 19b). There are no positions. In addition, the positioning structure 23 is further arranged on the upper side in the vertical direction, that is, closer to the end (the adjacent LED 17 side) than the LED 17 disposed on the uppermost side in the vertical direction among the LED 17 group intermittently arranged in parallel in the Y-axis direction. It is arranged at a position shifted to the opposite side. Since the positioning structure 23 includes a positioning concave portion 23b formed by recessing a part of the light guide plate 19 and a positioning convex portion 23a fitted therein, the inside of the light guide plate 19 is provided. For propagating light, it can be a hindrance to progress. Since the positioning structure 23 is arranged so as not to be opposed (offset) with respect to the LED 17 in the direction along the optical axis (X-axis direction), the light incident from the LED 17 into the light guide plate 19 is positioned. 23, and the optical path of the light propagating through the light guide plate 19 is hardly disturbed by the positioning structure 23. Moreover, the positioning structure 23 is arranged in the non-display area NAA so as not to exist in the display area AA in the liquid crystal panel 11. Thereby, it is possible to prevent a situation in which the positioning structure 23 is directly visually recognized by the user of the liquid crystal display device 10. Further, as shown in FIG. 6, the positioning structure 23 is arranged at a position overlapping the long side portion arranged on the upper end side in the vertical direction in the frame 16 in a plan view, and the long side portion of the frame 16. Thus, it is hidden from the eyes of the user of the liquid crystal display device 10.

This embodiment has the structure as described above, and its operation will be described next. In order to manufacture the liquid crystal display device 10, the separately manufactured liquid crystal panel 11, backlight device 12, bezel 13 and the like are assembled. Hereinafter, the manufacturing procedure of the backlight device 12 will be described mainly with respect to the manufacturing procedure of the liquid crystal display device 10.

When manufacturing the backlight device 12, first, a work of assembling a pair of LED substrates 18 on which the LEDs 17 are mounted in the chassis 14 is performed. The LED board 18 is accommodated from the front side at the end on the short side in the chassis 14 with the heat radiation plate portion 18b parallel to the bottom plate 14a of the chassis 14 and the LED mounting portion 18a parallel to the side plate 14b. Is done. At this time, the assembling directions of the LED substrates 18 are aligned so that the positioning convex portion 23a is positioned on the upper side in the vertical direction when the liquid crystal display device 10 is used. The LED board 18 is fixed to the chassis 14 with screws or the like in a state where the heat radiating plate portion 18b is in contact with the inner surface of the bottom plate 14a of the chassis 14 and the LED mounting portion 18a is in contact with the inner surface of the side plate 14b.

Subsequently, the work of assembling the light guide plate 19 in the chassis 14 is performed. The light guide plate 19 has a long side and a short side parallel to the long side and the short side of the chassis 14, and is positioned between the pair of LED boards 18 already attached to the chassis 14. From the front side. At this time, the assembly direction of the light guide plate 19 is adjusted so that the pair of positioning concave portions 23b are positioned on the upper side in the vertical direction when the liquid crystal display device 10 is used. When the light guide plate 19 is accommodated in the chassis 14, if the light guide plate 19 is displaced with respect to the pair of LED substrates 18 in the X-axis direction and the Y-axis direction, the pair of positioning convex portions 23 a At least one of the light guide plates 19 abuts against the plate surface 19c on the back side of the light guide plate 19 without fitting into the positioning concave portion 23b, so that the light guide plate 19 is inclined in the chassis 14. In that case, alignment is performed by adjusting the position of the light guide plate 19 in at least one of the X-axis direction and the Y-axis direction with respect to the pair of LED substrates 18. And if the light-guide plate 19 is correctly aligned with respect to a pair of LED board 18 about the X-axis direction and the Y-axis direction, a pair of positioning convex-shaped part 23a which stands | starts up from each heat sink part 18b toward the front side will become. The light guide plate 19 is fitted into a pair of positioning concave portions 23b formed on the back plate surface 19c of the light guide plate 19, so that the light guide plate 19 has its plate surface (main surface) as the bottom plate 14a and the heat radiating plate portion of the chassis 14. It is accommodated in the chassis 14 in a posture parallel to 18b. That is, whether or not the light guide plate 19 is accurately aligned with the pair of LED substrates 18 can be determined based on whether or not the surface of the light guide plate 19 accommodated in the chassis 14 is inclined.

As shown in FIGS. 5 and 6, the light guide plate 19 accommodated in the chassis 14 in the aligned state has the circumferential surfaces of the positioning convex portion 23 a and the positioning concave portion 23 b forming the positioning structure 23. By abutting, the X-axis direction and the Y-axis direction are not shaken with respect to the chassis 14 and the LED board 18 (LED 17), and are held in an appropriate position in a positioning state. When the light guide plate 19 is assembled in the chassis 14 in this way, the three optical members 15 are sequentially stacked on the light emitting surface 19 a of the light guide plate 19, and then the frame 16 is attached to the chassis 14. The backlight device 12 is manufactured by mounting. Then, the liquid crystal display device 10 is manufactured by assembling the liquid crystal panel 11 and the bezel 13 to the backlight device 12 (see FIG. 4).

When the power supply of the liquid crystal display device 10 manufactured as described above is turned on, the drive of the liquid crystal panel 11 is controlled by a control circuit (not shown), and the drive power from the LED drive circuit (not shown) is applied to each LED 17 on the LED substrate 18. The drive is controlled by being supplied to. The light from each LED 17 is guided by the light guide plate 19, so that the liquid crystal panel 11 is irradiated through the optical member 15, and a predetermined image is displayed on the liquid crystal panel 11. Hereinafter, the operation of the backlight device 12 will be described in detail.

When each LED 17 is turned on, the light emitted from each LED 17 enters the light incident surface 19b of the light guide plate 19 as shown in FIG. Here, although a predetermined space is held between the LED 17 and the light incident surface 19b, the space is sandwiched between the first reflective sheet 20 on the front side and the second reflective sheet 21 on the back side. The light from the LED 17 is repeatedly reflected by both the

reflection sheets

20 and 21, so that it is efficiently incident on the light incident surface 19b. The light incident on the light incident surface 19b is totally reflected at the interface with the external air layer in the light guide plate 19 or is reflected by the light guide reflection sheet 22 and is propagated through the light guide plate 19. The light is emitted from the light exit surface 19a by being reflected or scattered by a reflection part or a scattering part (not shown).

By the way, the incident efficiency when the light from the LED 17 is incident on the light incident surface 19b is held in the positional relationship in the X-axis direction between the LED 17 and the light incident surface 19b, that is, between the LED 17 and the light incident surface 19b. It fluctuates according to the interval (distance), and as the interval increases, the incidence efficiency decreases. Conversely, as the interval decreases, the incidence efficiency tends to improve. And even if the space | interval held between LED17 and the light-incidence surface 19b varies slightly, the incident efficiency at the time of the light from LED17 injecting into the light-incidence surface 19b will fluctuate | variate greatly, especially the said liquid crystal As the set value of the interval becomes smaller as the display device 10 becomes narrower, the variation rate of the incident efficiency when the interval is varied tends to increase. In the present embodiment, as shown in FIGS. 5 and 6, the LED substrate 18 and the light guide plate 19 are arranged in the X-axis direction and the Y-axis direction by providing the LED substrate 18 and the light guide plate 19 with the positioning structures 23, respectively. Since the LED board and the light guide plate are positioned indirectly via a part of the chassis as in the conventional case, the assembly error, etc. is as much as there are no inclusions. Is less affected, and the positioning accuracy is higher. As described above, the LED substrate 18 and the light guide plate 19 are positioned with high accuracy in the X-axis direction and the Y-axis direction by the positioning structure 23, so that the positional relationship in the X-axis direction between the LED 17 and the light incident surface 19b. Variation is extremely difficult to occur. Therefore, the incidence efficiency of the light incident on the light incident surface 19b from the LED 17 is less likely to vary, and the luminance of the outgoing light from the light incident on the light guide plate 19 is less likely to vary. . As described above, since the light incident efficiency to the light guide plate 19 and the luminance of the light emitted from the light guide plate 19 can be stabilized, the display quality of the image displayed on the liquid crystal panel 11 can be kept high.

Moreover, since the positioning convex portion 23a forming the positioning structure 23 is provided using the heat radiating plate portion 18b for radiating heat to the bottom plate 14a of the chassis 14 in the LED board 18, the heat radiating plate portion 18b Compared to the case where a structure that extends separately from the LED mounting portion 18a toward the light guide plate 19 is provided and the positioning convex portion 23a is provided there, the structure of the LED substrate 18 is simplified. In addition, the overall structure of the backlight device 12 can be simplified, the assembling work efficiency can be improved, and the manufacturing cost can be reduced.

Furthermore, as shown in FIG. 3, the positioning structure 23 is arranged so as not to overlap the LEDs 17 in the X-axis direction, and is closest to the end of the group of LEDs 17 intermittently arranged in parallel in the Y-axis direction. Therefore, it is difficult to interfere with the light emitted from the LED 17 and incident on the light incident surface 19b, and a situation that obstructs the optical path is avoided. Accordingly, luminance unevenness due to the positioning structure 23 is less likely to occur in the light emitted from the light emitting surface 19 a of the light guide plate 19. In addition, the positioning structure 23 is disposed in the non-display area NAA in the liquid crystal panel 11 and is disposed at a position overlapping the long side portion of the frame 16 in plan view (see FIG. 6). It is difficult for the user of the display device 10 to visually recognize the positioning structure 23, thereby further improving the display quality.

Here, with the use of the liquid crystal display device 10, when each LED 17 emits light, each LED 17 generates heat. As shown in FIG. 4, the generated heat is transmitted from the LED 17 to the heat radiating plate 18b via the LED mounting portion 18a, and further to the bottom plate 14a of the chassis 14 in contact with the heat radiating plate 18b. Since the heat radiating plate portion 18b is arranged over a range covering most of the short side direction at both ends on the short side of the bottom plate 14a of the chassis 14, heat is efficiently transferred to the bottom plate 14a. Therefore, high heat dissipation performance can be obtained. The heat from the LED 17 is also dissipated by being transmitted from the LED mounting portion 18 a to the side plate 14 b on the short side of the chassis 14. Although heat radiation from the LED 17 is achieved in this way, it is difficult to avoid a certain amount of heat storage in the chassis 14, and the light guide plate 19 may thermally expand with the heat storage. Even in that case, the light guide plate 19 is positioned at two positions separated in the X-axis direction by the pair of positioning structures 23 as shown in FIGS. The relative displacement with respect to the LED substrate 18 is regulated. Therefore, with the thermal expansion of the light guide plate 19, the amount of displacement of the light incident surface 19b in the direction approaching the LED 17 can be made very small, and the light incident surface 19b contacts the LED 17. Can be prevented. On the other hand, when the temperature in the chassis 14 decreases as the LEDs 17 are turned off, the light guide plate 19 that has been thermally expanded thermally contracts. Even in this case, since the light guide plate 19 is positioned by the pair of positioning structures 23, the light guide plate 19 is prevented from being displaced with respect to the LED substrates 18 due to thermal contraction.

As described above, the backlight device (illumination device) 12 according to the present embodiment includes the LED (light source) 17, the light incident surface 19 b that is arranged to face the LED 17 and receives light from the LED 17, and the incident light. A light guide plate 19 having a light emitting surface 19a for emitting the emitted light, an LED mounting portion (light source mounting portion) 18a on which the LED 17 is mounted, and a heat radiating plate portion 18b extending from the LED mounting portion 18a toward the light guide plate 19 side. The LED board (light source board) 18 including the LED board 18 and the light guide plate 19 is accommodated, and is parallel to the plate surface of the light guide plate 19 and sandwiches the heat radiating plate portion 18b with the light guide plate 19. The LED board 18 and the light guide plate 19 are formed on the chassis 14 having the bottom plate 14a, the heat radiating plate portion 18b, and the light guide plate 19, respectively, and are engaged with each other. Comprises a positioning structure 23 to position the direction toward the light entrance surface 19b at least LED 17, a.

In this way, the light emitted from the LED 17 enters the light incident surface 19b of the light guide plate 19 arranged to face the LED 17, and then propagates through the light guide plate 19 and then from the light emitting surface 19a. Emitted. Since the heat radiating plate portion 18b constituting the LED substrate 18 extends from the LED mounting portion 18a toward the light guide plate 19 and is sandwiched between the light guide plate 19 and the bottom plate 14a of the chassis 14, the heat radiating plate is temporarily provided. Compared to the case where the portion extends from the LED mounting portion 18a toward the side opposite to the light guide plate 19 side, this is preferable in reducing the size of the backlight device 12 and the like. Further, the heat generated from the LED 17 by the heat radiating plate portion 18b can be efficiently transmitted to the bottom plate 14a of the chassis 14 via the LED mounting portion 18a.

The LED substrate 18 and the light guide plate 19 are directly formed at least in the direction from the LED 17 toward the light incident surface 19b by the positioning structures 23 formed on the heat radiating plate portion 18b and the light guide plate 19 and fitted to each other. Compared to the conventional configuration in which the LED substrate 18 and the light guide plate 19 are indirectly positioned through a part of the chassis 14 as in the conventional case, the assembly error is as much as there is no inclusion. Thus, the accuracy of positioning is higher. This makes it difficult for the incident efficiency of the light incident from the LED 17 to the light incident surface 19b and the luminance of the light emitted from the light emitting surface 19a of the light guide plate 19 to vary, and thus the light utilization efficiency and the luminance of the emitted light. Can be stabilized. Moreover, since the positioning structure 23 is provided by using the heat radiating plate portion 18b extending from the LED mounting portion 18a toward the light guide plate 19 side in the LED substrate 18, it is temporarily separated from the heat radiating plate portion 18b. Compared with the case where a structure extending toward the light guide plate 19 is provided and the positioning structure 23 is provided there, it is preferable to simplify the entire structure.

The positioning structure 23 includes a positioning concave portion 23b formed on a plate surface of the light guide plate 19 facing the heat radiating plate portion 18b, and a positioning concave portion formed on the heat radiating plate portion 18b and projecting toward the light guide plate 19. It is comprised from the positioning convex-shaped part 23a fitted by 23b. In this way, since the protrusions are not formed on the plate surface of the light guide plate 19 facing the heat radiating plate portion 18b, the light guide plate 19 is excellent in handleability. In addition, although the LED board 18 is provided with the LED mounting part 18a and the LED 17 in the first place, although the positioning convex part 23a is formed on the heat radiating plate part 18b, the presence of the positioning convex part 23a is immediately It is difficult to become a cause of impairing the handleability of the substrate 18.

Further, the positioning structure 23 is arranged at a position that does not overlap with the LED 17 in the direction from the LED 17 toward the light incident surface 19b. In this way, the light incident on the light incident surface 19b of the light guide plate 19 from the LED 17 is less likely to hit the positioning structure 23, so that unevenness due to the positioning structure 23 is less likely to occur in the emitted light from the light emitting surface 19a. Become.

Further, a plurality of LEDs 17 are intermittently arranged along the light incident surface 19b, and the positioning structure 23 is a position that is shifted further to the end than the LED 17 that is arranged at the end most in the arrangement direction of the LEDs 17. It is arranged in. In this way, the unevenness of the emitted light due to the positioning structure 23 can be made more unlikely to occur as compared with the case where the positioning structure is arranged so as to be positioned between the adjacent LEDs 17.

Also, a pair of LED substrates 18 are arranged so as to sandwich the light guide plate 19, whereas the light guide plates 19 are incident on the LEDs 17 mounted on the pair of LED substrates 18 so as to face each other. A pair of surfaces 19b is provided, and the positioning structure 23 is provided on each of the heat radiating plate portions 18b and the light guide plate 19 included in the pair of LED substrates 18. In this way, each of the heat radiating plate portions 18b and the light guide plate 19 included in the pair of LED substrates 18 arranged so as to sandwich the light guide plate 19 are positioned relative to each other by the positioning structures 23 provided respectively. Incidence efficiencies of light incident from the LEDs 17 mounted on the pair of LED substrates 18 to the opposing light incident surfaces 19b are less likely to vary. Therefore, the brightness of the light emitted from the light exit surface 19a is less likely to be uneven.

Further, the LED mounting portion 18a rises from the heat radiating plate portion 18b and is arranged to face the light incident surface 19b, whereas the LED 17 has a top surface located on the opposite side of the mounting surface with respect to the LED mounting portion 18a. The light emitting surface 17a is a top surface emitting type. In this way, the top surface light emitting type LED 17 is provided on the LED mounting portion 18a that rises from the heat radiating plate portion 18b and is opposed to the light incident surface 19b, so that the heat radiating plate portion 18b rises. The freedom degree of arrangement | positioning of LED17 about a direction becomes high. Thereby, it becomes possible to arrange | position LED17 in the appropriate position with respect to the light-incidence surface 19b of the light-guide plate 19 so that the incident efficiency of light may become favorable.

<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIG. In this Embodiment 2, what changed the structure of LED117 and LED board 118 is shown. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

As shown in FIG. 9, the LED board 118 according to the present embodiment is configured such that the LED mounting portion 118 a extends along the heat radiating plate portion 118 b and the bottom plate 114 a of the chassis 114. That is, the LED substrate 118 has a single flat plate shape along the X-axis direction and the Y-axis direction as a whole. Specifically, the LED mounting portion 118a is housed in the chassis 114 with its plate surface parallel to the X-axis direction and the Y-axis direction in the same manner as the heat radiating plate portion 118b. It has been broken. And LED117 mounted in this LED mounting part 118a is made into the side light emission type by which the side surface adjacent to the mounting surface with respect to LED mounting part 118a is made into the light emission surface 117a. The LED 117 is configured to rise from the surface (mounting surface) facing the front side in the LED mounting portion 118a along the Z-axis direction, and the light emitting surface 117a is opposed to the light incident surface 119b of the light guide plate 119. Yes. A wiring pattern (not shown) extending along the Y-axis direction is formed on the mounting surface of the LED 117 in the LED mounting portion 118a. The LED board 118 according to the present embodiment is configured such that the LED mounting part 118a having the wiring pattern is parallel to the heat radiating plate part 118b, as compared with the LED board 18 (see FIG. 4) described in the first embodiment. In addition, since only the LED 117 rises in the Z-axis direction, the height is reduced in the Z-axis direction. Therefore, the light guide plate 119 can also be thinned in accordance with the rising height of the LED 117, and the backlight device 112 and the liquid crystal display device 110 as a whole can be thinned.

As described above, according to the present embodiment, the LED mounting portion 118a is configured to extend along the heat dissipation plate portion 118b, while the LED 117 is a side surface adjacent to the mounting surface with respect to the LED mounting portion 118a. Is a side light emitting type in which the light emitting surface 117a is used. In this case, the side surface light emitting type LED 117 is provided on the LED mounting portion 118a that is configured to extend along the heat radiating plate portion 118b, which is preferable in using the thin light guide plate 119. Therefore, it is also suitable for reducing the thickness of the backlight device 112 as a whole.

<Embodiment 3>
A third embodiment of the present invention will be described with reference to FIG. 10 or FIG. In the third embodiment, the optical member 215 is provided with the light shielding portion 24 and the configuration of the positioning structure 223 is changed. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted. FIG. 10 shows a planar configuration in a state where the optical member 215 is stacked on the light guide plate 219.

As shown in FIGS. 10 and 11, the optical member 215 according to the present embodiment is provided with a light shielding portion 24 that is disposed closer to the LED 217 than the light incident surface 219 b of the light guide plate 219 and shields light from the LED 217. Is included. A pair of light shielding portions 24 are provided at both ends of the optical member 215 on the short side, that is, both ends on the LED 217 side. The light shielding portion 24 is a separate component from the optical member 215, and is integrated by being attached to the optical member 215 with an adhesive or the like. The light shielding portion 24 is made of a synthetic resin, and the surface of the light shielding portion 24 exhibits a white color with excellent light reflectivity, similar to the

reflective sheets

220 and 222. In other words, the light shielding unit 24 is manufactured by using a reflection sheet that is generally used for the backlight device 212. Therefore, the light-shielding part 24 has extremely high light reflectivity and light-shielding property, the light reflectivity is set to a value close to 100% (for example, a range of 90% to 100%), and the light transmittance is 0. % (For example, a range of 0% to 10%). The light-shielding part 24 is disposed so as to protrude from the light incident surface 219b of the light guide plate 219 to the LED 217 side, and is disposed opposite to the first reflection sheet 220 disposed on the back side. The light emitted from the light can be efficiently incident on the light incident surface 219b while being repeatedly reflected between the first reflective sheet 220 and the light. Since the light-shielding part 24 has sufficient light-shielding property in addition to light reflectivity as described above, the light from the LED 217 is restricted from directly entering the end of the optical member 215 on the LED 217 side. It is possible to do. In the present embodiment, the second reflection sheet 21 described in the first embodiment is omitted as the light shielding unit 24 is installed.

The light shielding unit 24 is attached to a light diffusing plate 215a closest to the light guide plate 219, that is, the optical member 215 in which a plurality of sheets are stacked on each other, which is directly mounted on the light emitting surface 219a of the light guide plate 219. . As a result, the light from the LED 217 is blocked by the light shielding portion 24, so that it directly enters at least the end portion on the LED 217 side of each optical sheet 215b laminated on the front side of the diffusion plate 215a, or each optical sheet Entering each gap that may occur between 215b is prevented. The light shielding part 24 is attached to the back side of the pair of front and back main surfaces of the diffusion plate 215a, that is, the main surface on the light guide plate 119 side. As a result, the light from the LED 217 is blocked by the light blocking unit 24 and thus directly enters the end of the diffuser plate 215a on the LED 217 side or enters a gap that may occur between the diffuser plate 215a and the light guide plate 219. Is prevented.

As shown in FIG. 11, the light-shielding portion 24 includes a portion disposed on the LED 217 side with respect to the light incident surface 219b of the light guide plate 219 and a portion disposed on the side opposite to the LED 217 side with respect to the light incident surface 219b. In particular, the former is arranged over a range where the former overlaps the LED 217 in a plan view. That is, the light-shielding portion 24 is disposed in a range extending over the LED 217 side and the light emission surface 219a side while straddling the light incident surface 219b. As shown in FIG. 10, the light-shielding portion 24 has a vertically long rectangular shape with a constant width and extending along the short side direction of the optical member 215, that is, the LED 217 arrangement direction (Y-axis direction). Therefore, the light-shielding portion 24 crosses the area where the LEDs 217 are arranged (light source arrangement area) and the area where the LEDs 217 are not arranged (light source non-arrangement area) in the arrangement direction of the LEDs 217 and is arranged over almost the entire range. Yes. Thereby, the light emitted from the LEDs 217 arranged intermittently along the Y-axis direction can be generated between the end of the optical member 215 on the LED 217 side or between the stacked optical members 215, It is possible to more reliably block the gap that may occur between the optical member 215 and the light guide plate 219.

As shown in FIGS. 10 and 11, the positioning structure 223 according to the present embodiment is formed on the positioning convex portion 223a formed on the heat radiating plate portion 218b of the LED substrate 218 and the light guide plate 219 and positioned. A positioning concave portion 223b to which the convex portion 223a is fitted and a second positioning concave portion 223c that is formed on each optical member 215 and to which the positioning convex portion 223a is fitted. Among these, the positioning concave portion 223b is formed in a hole shape penetrating the light guide plate 219 in the plate thickness direction, and opens to the heat radiating plate portion 218b side and the optical member 215 side, respectively. The second positioning concave portion 223c is formed in a hole shape penetrating each optical member 215 in the thickness direction, and communicates with and aligns with the positioning concave portion 223b in the plane of each optical member 215. Arranged in position. A pair of second positioning concave portions 223c are arranged at two positions separated from each other in the X-axis direction at the upper end portion in the vertical direction of each optical member 215. The positioning convex portion 223a has a projecting dimension from the heat radiating plate 218b larger than the sum of the thickness of the light guide plate 219 and the thickness of each optical member 215. Thus, the positioning concave portions 223b and the second positioning concave portions 223c are collectively fitted.

When assembled, when the light guide plate 219 is accommodated in the chassis 214 with the LED substrate 218 attached to the chassis 214, the positioning convex portion 223a is fitted into the positioning concave portion 223b, so that the light guide plate 219 with respect to the LED substrate 218 is obtained. Are positioned. Thereafter, when the optical members 215 are sequentially stacked on the light guide plate 219, the positioning convex portions 223a are fitted into the second positioning concave portions 223c, thereby positioning the optical members 215 with respect to the LED substrate 218. Figured. At this time, the light shielding part 24 integrally provided on the diffusion plate 215a which is the optical member 215 is also positioned with high accuracy in the X-axis direction and the Y-axis direction with respect to the LED 217. The performance can be exhibited stably. The assembled liquid crystal display device 210 is used with the display surface of the liquid crystal panel 211 along the vertical direction. At this time, each optical member 215 is positioned with the light guide plate 219 and the positioning convex portion. It will be supported in the state suspended from the upper side of the vertical direction by 223a. Therefore, even when each optical member 215 undergoes thermal expansion or contraction due to a change in the thermal environment, deformation such as wrinkles or deflection is less likely to occur due to the weight of the optical member 215 itself. Thereby, luminance unevenness hardly occurs in the light emitted from the backlight device 212, and the display quality of the image displayed on the liquid crystal panel 211 can be improved.

As described above, according to the present embodiment, the optical member 215 is provided so as to face the light emitting surface 219a of the light guide plate 219, and the positioning concave portion 223b includes the light guide plate 219 and the plate. The optical member 215 is formed with a second positioning concave portion 223c into which the positioning convex portion 223a is fitted, whereas the optical member 215 is formed to penetrate in the thickness direction. By doing so, the positioning convex portion 223a penetrating the positioning concave portion 223b formed in the light guide plate 219 is fitted into the second positioning concave portion 223c formed in the optical member 215, whereby the light guide plate The optical member 215 can be positioned together with the 219.

Further, at the end of the optical member 215 on the LED 217 side, there is provided a light shielding portion 24 that protrudes toward the LED 217 side and is disposed closer to the LED 217 than the light incident surface 219b and blocks light from the LED 217. In this way, the light emitted from the LED 217 is blocked by the light blocking unit 24, for example, directly incident on the end of the optical member 215 on the LED 217 side, or between the light guide plate 219 and the optical member 215. It is prevented from entering the possible gap. Accordingly, it is possible to prevent the light from the LED 217 from being emitted outside without entering the light incident surface 219b of the light guide plate 219. Here, when the positioning convex portion 223a is fitted to the second positioning concave portion 223c, the LED 217 mounted on the LED substrate 218 and the light shielding portion 24 provided on the optical member 215 are connected from the LED 217 to the light incident surface 219b. Therefore, the light shielding performance by the above-described light shielding portion 24 can be stably exhibited.

Further, the light shielding portion 24 has light reflectivity for reflecting light. In this way, the light from the LED 217 can be reflected by the light shielding portion 24 and directed toward the light incident surface 219b. Thereby, the utilization efficiency of light can be improved.

The second positioning concave portion 223c has a hole shape penetrating the optical member 215 in the thickness direction, and the hole edge is supported in the vertical direction by the positioning convex portion 223a. In this way, when the positioning convex portion 223a is fitted to the second positioning concave portion 223c, the hole edge of the second positioning concave portion 223c is supported in the vertical direction by the positioning convex portion 223a. That is, since the optical member 215 can be suspended and supported by the positioning convex portion 223a, for example, even when the optical member 215 undergoes thermal expansion or contraction, the optical member 215 itself is wrinkled. It is assumed that deformation such as bending hardly occurs. Accordingly, luminance unevenness can be more effectively suppressed.

<Embodiment 4>
A fourth embodiment of the present invention will be described with reference to FIG. In this Embodiment 4, what changed arrangement | positioning of a pair of LED board 318 is shown. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

As shown in FIG. 12, a pair of LED substrates 318 according to the present embodiment are arranged at positions where the light guide plate 319 is sandwiched from both sides in the short side direction (Y-axis direction, vertical direction). The LED board 318 includes an LED mounting portion 318a extending along the side plate 314b on the long side of the chassis 314, and a heat radiating plate extending from the LED mounting portion 318a toward the light guide plate 319 along the Y-axis direction. Part 318b. On the other hand, among the outer peripheral end surfaces of the light guide plate 319, both end surfaces on the long side are light incident surfaces 319b that are opposed to the LEDs 317, respectively. Among the pair of LED substrates 318, a pair of positioning convex portions 323a constituting the positioning structure 323 is provided on the heat dissipation plate portion 318b of the LED substrate 318 disposed on the upper side in the vertical direction. The positioning convex portion 323a is arranged at a position further shifted closer to the end than the LED 317 located at the end of the LEDs 317 intermittently arranged in parallel along the X-axis direction. That is, the positioning structure 323 according to the present embodiment is disposed at the upper corner of the light guide plate 319 in the vertical direction.

<Embodiment 5>
Embodiment 5 of the present invention will be described with reference to FIG. The fifth embodiment should be called a further modification of the above-described fourth embodiment, and shows an LED substrate 418 arranged only on one end side of the light guide plate 419. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 4 is abbreviate | omitted.

As shown in FIG. 13, only one LED substrate 418 according to this embodiment is disposed on the lower side in the vertical direction with respect to the light guide plate 419. A pair of positioning convex portions 423a constituting the positioning structure 423 is formed on the heat radiating plate portion 418b constituting the LED substrate 418, and the arrangement thereof is a lower corner portion in the vertical direction of the light guide plate 419. .

<Embodiment 6>
Embodiment 6 of the present invention will be described with reference to FIG. In the sixth embodiment, LED substrates 518 are provided corresponding to the four sides of the light guide plate 519, respectively. In addition, the overlapping description about the same structure, an effect | action, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

As shown in FIG. 14, the LED substrate 518 according to the present embodiment includes a pair of first LED substrates 518 </ b> A disposed at positions where the light guide plate 519 is sandwiched from both sides in the long side direction (X-axis direction), and the light guide plate 519. And a pair of second LED substrates 518B arranged at positions sandwiched from both sides in the short side direction (Y-axis direction, vertical direction). Since the configuration of the pair of first LED boards 518A is the same as that of the LED board 18 described in the first embodiment including the positioning structure 523, overlapping description is omitted. The LED mounting portion 518Ba of the second LED substrate 518B has a length equivalent to the long side dimension of the light guide plate 519, and a plurality of LEDs 517 are intermittently arranged in parallel along the length direction (X-axis direction). Has been. The heat dissipation plate portion 518Bb of the second LED substrate 518B has a shorter dimension in the X-axis direction than the LED mounting portion 518Ba, and the difference is the extension length dimension of the heat dissipation plate portion 518Aa of the pair of first LED substrates 518A. It is about a minute. That is, the heat dissipation plate portion 518Ba of the second LED substrate 518B is sized so as not to overlap the heat dissipation plate portion 518Aa of the first LED substrate 518A. On the other hand, among the outer peripheral end surfaces of the light guide plate 519, both end surfaces on the short side are the first light incident surfaces 519Ab facing each LED 517 mounted on the first LED substrate 518A, respectively. Both end surfaces on the long side are second light incident surfaces 519Bb that face each LED 517 mounted on the second LED substrate 518B.

<Embodiment 7>
A seventh embodiment will be described with reference to FIG. 15 or FIG. The seventh embodiment shows a configuration in which only the optical member 615 is positioned.

In this embodiment, as shown in FIGS. 15 and 16, the positioning structure 623 includes a positioning convex portion 623 a formed on the heat radiating plate portion 618 b of the LED substrate 618 and a positioning concave portion formed on each optical member 615. 623b, and is not formed on the light guide plate 619. The optical member 615 has a size wider than that of the light guide plate 619 in a plan view, and the positioning concave portion 623b described above penetrates in the thickness direction in a non-overlapping portion that does not overlap with the light guide plate 619. Is formed. Similarly, the LED substrate 618 has a heat radiating plate portion 618b having a size over a wider range than the light guide plate 619 in a plan view, and the positioning convex portion 623a described above is formed on a non-overlapping portion that does not overlap the light guide plate 619. Is formed. In the positioning convex portion 623a, the projecting dimension from the heat sink plate 618b is larger than the sum of the thickness of the light guide plate 619 and the thickness of each optical member 615. Thus, each positioning concave portion 623b is fitted in the side position of the light guide plate 619. The same light shielding portion 624 as that described in the third embodiment is provided at the end of the optical member 615 on the LED 617 side. Therefore, the light shielding performance of the light shielding portion 624 can be stably exhibited by accurately positioning the optical member 615, the LED substrate 618, and the LED 617 in the X-axis direction by the positioning structure 623.

<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 to sixth embodiments described above, the positioning structure is shown in which the positioning convex portion is formed on the LED substrate side and the positioning concave portion is formed on the light guide plate side. You may make it form a concave-shaped part and a positioning convex-shaped part in the light-guide plate side, respectively. In addition, when applying the above-mentioned technical matter to Embodiment 3, while providing the 1st positioning convex part which protrudes toward the heat radiating plate part side in a light-guide plate, it protrudes 2nd toward each optical member side. A positioning convex portion is provided, the first positioning convex portion is fitted into the positioning concave portion of the heat radiating plate portion, and the second positioning convex portion is fitted into the second positioning concave portion of each optical member. What should I do?

(2) In Embodiments 1, 2, 4 to 6 described above, the positioning concave portion is formed in a concave shape that does not penetrate the light guide plate in the plate thickness direction. However, the positioning concave portion has the thickness of the light guide plate. It is also possible to adopt a configuration that is formed in a hole shape penetrating in the direction. In that case, the positioning convex portion is sized so as to protrude from the light emitting surface to the front side in a state of being fitted in the hole-shaped positioning concave portion, or not to protrude from the light emitting surface (the light emitting surface and (A size that is flush or a size that retracts more than the light exit surface).

(3) In addition to the first to sixth embodiments described above, the arrangement of the positioning structure can be changed as appropriate. For example, in the first to fourth and sixth embodiments, the positioning structure can be arranged near the lower end portion in the vertical direction of the light guide plate, near the central portion in the vertical direction, or the like. Further, in the fifth embodiment, the LED substrate can be arranged on the upper side in the vertical direction, and the positioning structure can be arranged in the vicinity of the upper end portion in the vertical direction or the central portion in the vertical direction on the light guide plate.

(4) In addition to the above (3), when changing the arrangement of the positioning structure, for example, the positioning structure can be arranged between adjacent LEDs arranged intermittently in parallel. It is also possible to arrange the positioning structure so as to face the light emitting surface of the LED.

(5) In addition to the first to sixth embodiments described above, the specific shape of the positioning structure can be changed as appropriate. For example, the positioning convex portion and the positioning concave portion (second positioning concave portion) may have a circular shape, an elliptical shape, a square shape, a trapezoidal shape, a rhombus shape, a triangular shape, a pentagonal or more polygonal shape in a plan view. Is possible.

(6) In the first to sixth embodiments described above, a pair of positioning structures is shown, but it is of course possible to change the number of positioning structures to three or more.

(7) Besides the first to sixth embodiments described above, the formation range of the heat sink portion of the LED substrate can be changed as appropriate. For example, it is good also as a structure formed in the range which the heat sink part of an LED board covers the bottom face of a light-guide plate over the whole region, In that case, the freedom degree of arrangement | positioning of a positioning structure further increases. Moreover, it is also possible to change the planar shape of the heat sink part of an LED board other than a square shape.

(8) In the above-described third embodiment, in addition to the optical member having the light shielding portion, the second positioning concave portion is formed on the optical member not having the light shielding portion, and the positioning is performed. It is also possible to form the second positioning concave portion only in the optical member having the portion and not to form the second positioning concave portion in the optical member not having the light shielding portion.

(9) In the third embodiment described above, the configuration in which the positioning is achieved by forming the second positioning concave portion in the optical member having the light shielding portion has been described, but the configuration in which all the optical members do not have the light shielding portion. In (for example, the configuration as in the first embodiment described above), it is also possible to form a second positioning concave portion in each optical member so as to position the optical member.

(10) The configuration described in the second embodiment can be applied to the configurations described in the third to sixth embodiments.

(11) The configuration described in the third embodiment can be applied to the configurations described in the fourth to sixth embodiments.

(12) In Embodiments 1 to 6 described above, the case where three optical members are used has been exemplified. However, the number of optical members used can be appropriately changed to other than three (two or less, four or more). Is possible. Moreover, the specific kind of optical member to be used can be changed as appropriate.

(13) In addition to the above-described Embodiments 4 to 6, a total of three LED substrates, one for each of the long-side ends and the short-side ends of the light guide plate, The present invention also includes a configuration in which a total of three are arranged one by one with respect to both end portions on the side and one end portion on the long side.

(14) In each of the above-described embodiments, the color portion of the color filter included in the liquid crystal panel is exemplified as three colors of R, G, and B. However, the color portion may be four or more colors.

(15) In each of the above-described embodiments, an LED is used as the light source. However, other light sources such as an organic EL can be used.

(16) In each of the embodiments described above, a TFT is used as a switching element of a liquid crystal display device. However, the present invention can also be applied to a liquid crystal display device using a switching element other than TFT (for example, a thin film diode (TFD)). In addition to the liquid crystal display device for display, the present invention can also be applied to a liquid crystal display device for monochrome display.

(17) In each of the above-described embodiments, the liquid crystal display device using the liquid crystal panel as the display panel has been exemplified. However, the present invention can also be applied to display devices using other types of display panels.

(18) In each of the above-described embodiments, the television receiver provided with the tuner is exemplified, but the present invention is also applicable to a display device that does not include the tuner.

10, 110 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel (display panel), 12, 112 ... Backlight device (illumination device), 14, 114, 214, 314 ... Chassis , 14a, 114a ... bottom plate, 17, 117, 217, 317, 517 ... LED (light source), 17a, 117a ... light emitting surface, 18, 118, 218, 318, 418, 518 ... LED Board (light source board), 18a, 118a, 218a, 318a, 418a, 518a, 518Aa, 518Ba ... LED mounting part (light source mounting part), 18b, 118b, 218b, 318b, 418b, 518Ab, 518Bb ... heat dissipation Plate part, 19, 119, 219, 319, 419, 519 ... light guide plate, 19a, 219a ... light emitting surface, 19b, 219b, 319b ... light incident surface, 19c ... bottom surface (plate surface) ), 3, 223, 323, 423, 523 ... positioning structure, 23a, 223a, 323a, 423a ... positioning convex part, 23b, 223b ... positioning concave part, 215 ... optical member, 223c ... Second positioning concave portion, 518A ... first LED substrate (light source substrate), 518B ... second LED substrate (light source substrate), 519Ab ... first light incident surface (light incident surface), 519Bb ... Second light incident surface (light incident surface), TV ... TV receiver

Claims

A light source;
A light guide plate disposed opposite to the light source and having a light incident surface on which light from the light source is incident, and a light emitting surface for emitting the incident light;
A light source board having a light source mounting part on which the light source is mounted and a heat radiating plate part extending from the light source mounting part toward the light guide plate,
A chassis that houses the light source substrate and the light guide plate, and has a bottom plate that is parallel to the plate surface of the light guide plate and sandwiches the heat radiating plate portion with the light guide plate;
A positioning structure for positioning the light source substrate and the light guide plate at least in the direction from the light source toward the light incident surface by being formed on the heat radiating plate portion and the light guide plate, respectively, and engaging with each other. A lighting device comprising:
The positioning structure includes a positioning concave portion formed on a surface of the light guide plate facing the heat dissipation plate portion, a positioning concave portion formed on the heat dissipation plate portion, and projecting toward the light guide plate to fit into the positioning concave portion. The illuminating device according to claim 1, wherein the illuminating device comprises a positioning convex portion to be joined.
An optical member disposed opposite to the light exit surface of the light guide plate is provided;
The positioning concave portion is configured to penetrate the light guide plate in the plate thickness direction, whereas the optical member is formed with a second positioning concave portion into which the positioning convex portion is fitted. The lighting device according to claim 2.
The light source side end portion of the optical member is provided with a light shielding portion that protrudes toward the light source side and is disposed closer to the light source side than the light incident surface and blocks light from the light source. Item 4. The lighting device according to Item 3.
The illuminating device according to claim 4, wherein the light shielding part has light reflectivity for reflecting light.
The second positioning concave portion has a hole shape penetrating the optical member in the thickness direction, and a hole edge of the second positioning concave portion is supported in the vertical direction by the positioning convex portion. The lighting device according to any one of the above.
The lighting device according to any one of claims 1 to 6, wherein the positioning structure is arranged at a position that does not overlap the light source in a direction from the light source toward the light incident surface.
A plurality of the light sources are arranged intermittently along the light incident surface,
The lighting device according to claim 7, wherein the positioning structure is arranged at a position further shifted toward the end than the light source arranged at the end in the arrangement direction of the light sources.
The light source substrates are arranged in a pair so as to sandwich the light guide plate, whereas the light guide plates are opposed to the light sources mounted on the pair of light source substrates, respectively. A pair of surfaces,
The lighting device according to any one of claims 1 to 8, wherein the positioning structure is provided on each of the heat radiating plate portions and the light guide plate of the pair of light source substrates.
The light source mounting portion rises from the heat radiating plate portion and is arranged to face the light incident surface, whereas the light source has a top surface located on the opposite side of the mounting surface with respect to the light source mounting portion. The lighting device according to any one of claims 1 to 9, comprising a top-emitting LED that is a surface.
The light source mounting portion is configured to extend along the heat radiating plate portion, whereas the light source is a side-emitting LED whose side surface adjacent to the mounting surface with respect to the light source mounting portion is a light emitting surface. The lighting device according to claim 1, comprising:
A display device comprising: the illumination device according to any one of claims 1 to 11; and a display panel that performs display using light from the illumination device.
13. The display device according to claim 12, 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 12 or claim 13.