Display device and television set

This display device includes a display device body, a display portion arranged on the front side of the display device body, a light source substrate, a light guide plate arranged on the rear side of the display portion to be opposed to the light source substrate mounted with the light source, having a light incident surface including a side surface receiving light emitted from the light source, a heat sink arranged on the rear side of the light guide plate, including a light source substrate fixing portion to which the light source substrate is attached and fixed by a double-faced adhesive tape, and a substrate pressing portion pressing the front end surface of the light source substrate attached to the light source substrate fixing portion in a direction toward the bottom surface of the heat sink in a surface contact state.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device and a television set, and more particularly, it relates to a display device and a television set each including a light source substrate and a light guide plate.

2. Description of the Background Art

A display device including a light source substrate and a light guide plate is known in general, as disclosed in Japanese Patent Laying-Open No. 2007-163620.

Japanese Patent Laying-Open No. 2007-163620 discloses a liquid crystal display device (display device) including a liquid crystal display device body (display device body), a liquid crystal panel (display portion) arranged on the front side of the liquid crystal display device body, displaying an image, and a circuit board (light source substrate) mounted with an LED light source (light source) supplying light to the liquid crystal panel. This liquid crystal display device further includes a light guide plate opposed to the circuit board mounted with the LED light source on the rear side of the liquid crystal panel, having a light incident surface including a side surface receiving light emitted from the LED light source, guiding the light to the liquid crystal panel. This liquid crystal display device further includes a lower frame (heat sink) arranged on the rear side of the light guide plate, including a board fixing portion (light source substrate fixing portion) to which the circuit board is attached and fixed by a double-faced adhesive tape and an upper frame including a projecting portion coming into line contact with a side of the circuit board on the front side. The board fixing portion is formed by substantially vertically bending a part of the lower frame frontward.

In this liquid crystal display device, after completion of assembling, the circuit board (light source substrate) is held between the projecting portion of the upper frame and the lower frame in a state where the side of the circuit board on the front side comes into line contact with the projecting portion of the upper frame, whereby the circuit board is inhibited from falling down to the light guide plate when the double-faced adhesive tape is peeled off. Although the projecting portion of the upper frame comes into line contact with the side of the circuit board on the front side after the completion of assembling, it is not clear whether or not the projecting portion of the upper frame presses the side of the circuit board on the front side.

Conventionally, when the circuit board is attached to the board fixing portion of the lower frame, the circuit board is turned toward the board fixing portion, employing a pressed portion as a supporting point while the circuit board is inclined and the lower side (rear side) of a surface of the circuit board attached with the double-faced adhesive tape is pressed to a position of a surface of the vertically extending board fixing portion slightly distanced in the height direction from a bottom portion (of the lower frame). Therefore, the lower side of the circuit board attached to the board fixing portion may be slightly separated (displaced) in the height direction from the lower frame, and in this case, the LED light source is conceivably positionally displaced in the height direction from the light incident surface of the light guide plate.

In the liquid crystal display device according to Japanese Patent Laying-Open No. 2007-163620, however, the projecting portion of the upper frame simply comes into line contact with the side of the circuit board on the front side after completion of assembling, so that the separation (positional displacement) of the circuit board from the lower frame may be unable to be sufficiently modified. Therefore, the quantity of light incident on the light guide plate may be disadvantageously reduced by positional displacement between the LED light source and the light incident surface of the light guide plate.

SUMMARY OF THE INVENTION

The present invention has been proposed in order to solve the aforementioned problem, and an object of the present invention is to provide a display device and a television set each capable of suppressing a reduction in the quantity of light incident on a light guide plate by suppressing positional displacement between a light source and a light incident surface of the light guide plate.

A display device according to a first aspect of the present invention includes a display device body, a display portion arranged on the front side of the display device body, displaying an image, a light source substrate mounted with a light source supplying light to the display portion, a light guide plate arranged on the rear side of the display portion to be opposed to the light source substrate mounted with the light source, having a light incident surface including a side surface receiving light emitted from the light source, guiding the light to the display portion, a heat sink arranged on the rear side of the light guide plate, including a light source substrate fixing portion to which the light source substrate is attached and fixed by a double-faced adhesive tape, and a substrate pressing portion pressing the front end surface of the light source substrate attached to the light source substrate fixing portion in a direction toward the bottom surface of the heat sink in a surface contact state.

As hereinabove described, the display device according to the first aspect of the present invention is provided with the substrate pressing portion pressing the front end surface of the light source substrate attached to the light source substrate fixing portion in the direction toward the bottom surface of the heat sink in the surface contact state, whereby the front end surface of the light source substrate attached to the light source substrate fixing portion can be brought into surface contact with the substrate pressing portion to be pressed with force only in the direction toward the bottom surface of the heat sink by the substrate pressing portion, and hence sufficient pressing force to move the light source substrate toward the bottom surface of the heat sink can be obtained also when the light source substrate is attached to the light source substrate fixing portion, and the front end surface of the light source substrate can be stably pressed due to surface contact. Therefore, the separation (positional displacement) of the light source substrate from the bottom surface of the heat sink can be sufficiently modified even when the light source substrate is attached while separated (positionally displaced) toward the front side. Consequently, positional displacement between the light incident surface of the light guide plate and the light source can be suppressed, and hence a reduction in the quantity of light incident on the light guide plate can be suppressed. Furthermore, a reduction in the quantity of light incident on the light guide plate can be suppressed, and hence a reduction in luminance of light emitted from the light guide plate can be suppressed.

In the aforementioned display device according to the first aspect, the front end surface of the light source substrate is preferably flattened, and a portion of the substrate pressing portion pressing the front end surface of the light source substrate is preferably flattened. According to this structure, the front end surface of the light source substrate can be easily pressed while coming into surface contact with the portion of the substrate pressing portion pressing the front end surface of the light source substrate to be stabilized.

In the aforementioned display device according to the first aspect, a plurality of substrate pressing portions are preferably provided at prescribed intervals along the extensional direction of the light source substrate in a position corresponding to the front end surface of the light source substrate. According to this structure, the entire front end surface of the light source substrate can be easily pressed by the plurality of substrate pressing portions.

In the aforementioned display device according to the first aspect, the heat sink is preferably made of metal, the light source substrate fixing portion is preferably formed by bending a part of the heat sink frontward, the light source substrate preferably includes a rear end surface opposite to the front end surface in addition to the front end surface pressed by the substrate pressing portion, and the front end surface of the light source substrate is preferably pressed in the direction toward the bottom surface of the heat sink so that the rear end surface of the light source substrate comes into contact with the heat sink. According to this structure, the light source substrate can be accurately positioned by being held between the substrate pressing portion and the heat sink, and hence positional displacement between the light incident surface of the light guide plate and the light source can be effectively suppressed.

In this case, the rear end surface of the light source substrate is preferably flattened, and a portion of the heat sink coming into contact with the rear end surface of the light source substrate is preferably flattened. According to this structure, the rear end surface of the light source substrate and the portion of the heat sink coming into contact with the rear end surface of the light source substrate can be brought into contact with each other in a stable state, and hence the front end surface of the light source substrate can be more stably pressed by the substrate pressing portion.

In the aforementioned display device according to the first aspect, a light irradiation portion of the light source is preferably opposed to the light incident surface of the light guide plate in a state where the front end surface of the light source substrate attached to the light source substrate fixing portion is pressed in the direction toward the bottom surface of the heat sink by the substrate pressing portion. According to this structure, light emitted from the light irradiation portion of the light source can be guided to the light incident surface of the light guide plate in a state where the separation (positional displacement) of the light source substrate from the bottom surface of the heat sink is modified, and hence a reduction in the quantity of light incident on the light guide plate can be further suppressed.

In the aforementioned structure having the heat sink made of metal, the heat sink preferably includes a concave portion in a position corresponding to the rear end surface of the light source substrate, and the rear end surface of the light source substrate is preferably fitted into the concave portion. According to this structure, the separation (positional displacement) of the light source substrate from the bottom surface of the heat sink can be modified while the movement (displacement) of the rear end surface of the light source substrate in a direction toward the light guide plate (a direction perpendicular to a direction separating the light source substrate from the bottom surface of the heat sink) is suppressed by bringing the rear end surface of the light source substrate into contact with the concave portion. Therefore, positional displacement between the light incident surface of the light guide plate and the light source can be more effectively suppressed.

In the aforementioned structure having the heat sink made of metal, the double-faced adhesive tape is preferably shear-deformed in the direction toward the bottom surface of the heat sink in a state where the front end surface of the light source substrate is pressed by the substrate pressing portion so that the rear end surface of the light source substrate is moved to come into contact with the heat sink. According to this structure, the separation (positional displacement) of the light source substrate from the heat sink can be modified while the adhesive effect of the light source substrate on the light source substrate fixing portion is maintained when the front end surface of the light source substrate is pressed in the direction toward the bottom surface of the heat sink by the substrate pressing portion.

In this case, the double-faced adhesive tape is preferably configured to maintain adhesion of the light source substrate to the heat sink when the double-faced adhesive tape is shear-deformed in the direction toward the bottom surface of the heat sink. According to this structure, the separation of the light source substrate from the heat sink can be modified while the adhesive effect of the light source substrate on the light source substrate fixing portion is reliably maintained.

In the aforementioned structure having the shear-deformed double-faced adhesive tape, the double-faced adhesive tape is preferably attached to a position of the light source substrate separated by a prescribed interval from the rear end surface of the light source substrate. According to this structure, utilizing the interval between the position of the attached double-faced adhesive tape and the rear end surface of the light source substrate, the light source substrate can be moved to modify the separation of the light source substrate from the heat sink when the double-faced adhesive tape is shear-deformed. Thus, sufficient pressing force to move the light source substrate toward the bottom surface of the heat sink can be easily obtained.

In the aforementioned structure having the shear-deformed double-faced adhesive tape, the double-faced adhesive tape preferably has a thickness sufficient for shear-deformation in the direction toward the bottom surface of the heat sink. According to this structure, the double-faced adhesive tape can be easily shear-deformed in the direction toward the bottom surface of the heat sink.

The aforementioned display device according to the first aspect preferably further includes a resin frame configured to fix the light guide plate, arranged on the front side of the light source substrate, and the substrate pressing portion is preferably integrally formed on the resin frame to extend along the extensional direction of the front end surface of the light source substrate. According to this structure, an increase in the number of components can be suppressed, unlike the case where the substrate pressing portion is provided separately from the resin frame. Furthermore, a contact area between the substrate pressing portion and the front end surface of the light source substrate can be increased by the substrate pressing portion extending along the extensional direction of the front end surface of the light source substrate, and hence the front end surface of the light source substrate can be pressed in a more stable state to modify the separation (positional displacement) of the light source substrate from the heat sink.

In this case, the aforementioned display device preferably further includes a rear frame provided on the rear side of the heat sink, the resin frame preferably includes a first engaging portion, the rear frame preferably includes a second engaging portion engaging with the first engaging portion, and the substrate pressing portion is preferably configured to press the front end surface of the light source substrate while the first engaging portion and the second engaging portion engage with each other so that the front end surface of the light source substrate is held between the resin frame and the rear frame. According to this structure, the front end surface of the light source substrate can be pressed by the substrate pressing portion simultaneously when the resin frame is mounted on the rear frame, and hence an assembly operation can be simplified.

In the aforementioned structure including the resin frame, the first engaging portion of the resin frame preferably includes a hole, the second engaging portion of the rear frame preferably includes a claw portion, and the hole and the claw portion preferably engage with each other so that the movement of the resin frame and the rear frame in a direction separating from each other is restricted. According to this structure, an interval between the resin frame and the rear frame engaging with each other can be maintained constant, and hence a state of holding the light source substrate between the resin frame and the rear frame can be easily maintained.

In the aforementioned structure including the resin frame, the display device preferably further includes a light guide plate pressing portion integrally provided on the resin frame, the light source substrate preferably includes the front end surface pressed by the substrate pressing portion and a rear end surface opposite to the front end surface, an elastic member is preferably arranged on the rear side of the light guide plate, the substrate pressing portion and the light guide plate pressing portion provided integrally with the resin frame are preferably configured to press the front end surface of the light source substrate and a front surface of the light guide plate, respectively, in the direction toward the bottom surface of the heat sink in a surface contact state, the rear end surface of the light source substrate preferably comes into contact with the heat sink in a state where the front end surface of the light source substrate is pressed in the direction toward the bottom surface of the heat sink, and the light guide plate is preferably configured to be supported from the rear side toward the front side by the elastic member while the front side of the light guide plate is pressed in the direction toward the bottom surface of the heat sink. According to this structure, the movement of the front end surface of the light source substrate and the front surface of the light guide plate in a direction opposite to the direction toward the bottom surface of the heat sink can be restricted by the substrate pressing portion and the light guide plate pressing portion, respectively, and the light guide plate can be supported toward the front side by the elastic member and be positioned while the light source substrate is held between the substrate pressing portion and the heat sink and is positioned. Thus, positional displacement between the light incident surface of the light guide plate and the light source can be more accurately suppressed.

In the aforementioned structure further including the light guide plate pressing portion integrally provided on the resin frame, a reflective sheet is preferably arranged between the light guide plate and the elastic member, and the light guide plate is preferably configured to be supported through the reflective sheet from the rear side toward the front side by the elastic member while the front side of the light guide plate is pressed in the direction toward the bottom surface of the heat sink. According to this structure, light leakage from the light guide plate to the rear side can be suppressed, the movement of the front end surface of the light source substrate and the front surface of the light guide plate in the direction opposite to the direction toward the bottom surface of the heat sink can be restricted by the substrate pressing portion and the light guide plate pressing portion, respectively, and the light guide plate can be supported toward the front side by the elastic member and be positioned while the light source substrate is held between the substrate pressing portion and the heat sink and is positioned.

In the aforementioned display device according to the first aspect, the display device body preferably has a substantially rectangular shape as viewed from a front side, the light source substrate preferably includes a single light source substrate provided along one side of the edge of the display device body having the substantially rectangular shape, and the substrate pressing portion is preferably provided in a position corresponding to the front end surface of the single light source substrate on one side of the edge of the display device body. According to this structure, a reduction in the pressing force of the substrate pressing portion pressing the light source substrate can be suppressed, unlike the case where a plurality of light source substrates and a plurality of substrate pressing portions are provided along a plurality of sides of the edge of the display device body having the substantially rectangular shape, for example. Consequently, sufficient pressing force to move the light source substrate toward the bottom surface of the heat sink can be easily obtained.

In the aforementioned structure in which the heat sink includes the concave portion, a plurality of light sources are preferably provided in the extensional direction of the light source substrate, and the light irradiation portion of each of the plurality of light sources is preferably opposed to the light incident surface of the light guide plate in the state where the front end surface of the light source substrate attached to the light source substrate fixing portion is pressed in the direction toward the bottom surface of the heat sink by the substrate pressing portion. According to this structure, even when the light source substrate provided with the plurality of light sources is attached while separated (positionally displaced) toward the front side, the front end surface of the light source substrate attached to the light source substrate fixing portion can be brought into surface contact with the substrate pressing portion to be pressed with the force only in the direction toward the bottom surface of the heat sink by the substrate pressing portion, and hence positional displacement between the light incident surface of the light guide plate and the plurality of light sources can be suppressed. Therefore, a reduction in the quantity of light incident on the light guide plate from the plurality of light sources can be suppressed.

A television set according to a second aspect of the present invention includes a television display device body, a receiving portion receiving a broadcast signal, a display portion arranged on the front side of the television display device body, displaying an image, a light source substrate mounted with a light source supplying light to the display portion, a light guide plate arranged on the rear side of the display portion to be opposed to the light source substrate mounted with the light source, having a light incident surface including a side surface receiving light emitted from the light source, guiding the light to the display portion, a heat sink arranged on the rear side of the light guide plate, including a light source substrate fixing portion to which the light source substrate is attached and fixed by a double-faced adhesive tape, and a substrate pressing portion pressing the front end surface of the light source substrate attached to the light source substrate fixing portion in a direction toward the bottom surface of the heat sink in a surface contact state.

As hereinabove described, the television set according to the second aspect of the present invention is provided with the substrate pressing portion pressing the front end surface of the light source substrate attached to the light source substrate fixing portion in the direction toward the bottom surface of the heat sink in the surface contact state, whereby the front end surface of the light source substrate attached to the light source substrate fixing portion can be brought into surface contact with the substrate pressing portion to be pressed with force only in the direction toward the bottom surface of the heat sink by the substrate pressing portion, and hence sufficient pressing force to move the light source substrate toward the bottom surface of the heat sink can be obtained also when the light source substrate is attached to the light source substrate fixing portion, and the front end surface of the light source substrate can be stably pressed due to surface contact. Therefore, the separation (positional displacement) of the light source substrate from the bottom surface of the heat sink can be sufficiently modified even when the light source substrate is attached while separated (positionally displaced) toward the front side. Consequently, positional displacement between the light incident surface of the light guide plate and the light source can be suppressed, and hence a reduction in the quantity of light incident on the light guide plate can be suppressed. Furthermore, a reduction in the quantity of light incident on the light guide plate can be suppressed, and hence a reduction in luminance of light emitted from the light guide plate can be suppressed.

In the aforementioned television set according to the second aspect, the front end surface of the light source substrate is preferably flattened, and a portion of the substrate pressing portion pressing the front end surface of the light source substrate is preferably flattened. According to this structure, the front end surface of the light source substrate can be easily pressed with the force only in the direction toward the bottom surface of the heat sink while coming into surface contact with the portion of the substrate pressing portion pressing the front end surface of the light source substrate.

According to the present invention, as hereinabove described, positional displacement between the light source and the light incident surface of the light guide plate can be suppressed, and hence a reduction in the quantity of light incident on the light guide plate can be suppressed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention is hereinafter described with reference to the drawings.

The structure of a TV (television set)100according to the embodiment of the present invention is now described with reference toFIGS. 1 to 6. The TV100is an example of the “display device” in the present invention.

The TV100according to the embodiment of the present invention has a substantially rectangular shape as viewed from the front side (X1 side), as shown inFIG. 1. The TV100includes a front frame1having an opening1aand a rear frame2. The rear frame2includes claw portions21(seeFIG. 3) engaging with holes91(seeFIG. 3) of a resin frame9described later. A display portion10displaying an image is exposed from the opening1aof a TV body100a(front frame1). The display portion10is mainly constituted by a liquid crystal cell. The TV100is configured to be capable of receiving a broadcast signal by a receiving portion20. The TV body100ais an example of the “display device body” in the present invention.

Inside the TV100, a heat sink3and an LED module4including a plurality of LEDs42are provided, as shown inFIGS. 2 and 3. As shown inFIG. 3, a cushion6, a reflective sheet7a, a light guide plate8, and an optical sheet7bare stacked in this order from the rear side (X2 side) on the front side (X1 side) of the heat sink3. The resin frame9is arranged on the front side of an LED substrate41. The display portion10(seeFIG. 1) is arranged on the front side of the resin frame9. The LED module4is mounted on the heat sink3through a double-faced adhesive tape5, as shown inFIGS. 2,3, and5. The LEDs42are examples of the “light source” in the present invention. The LED substrate41is an example of the “light source substrate” in the present invention.

According to this embodiment, the heat sink3has a function of releasing the heat of the LEDs42. The heat sink3is made of metal (sheet metal). The heat sink3includes a heat sink body portion31and an LED substrate fixing portion32, as shown inFIGS. 2,3, and5. Specifically, the heat sink3(heat sink body portion31) is arranged on the rear side (X2 side) of the light guide plate8, as shown inFIG. 3. The heat sink body portion31is flattened to extend in a direction Y. Specifically, a portion of the heat sink3(heat sink body portion31) coming into contact with the rear end surface412of the LED substrate41is flattened. The LED substrate fixing portion32is configured to fix the LED substrate41by the double-faced adhesive tape5. The LED substrate fixing portion32is formed by substantially vertically bending a portion of the heat sink3on a Y1 side frontward (along arrow X1). The rear frame2is arranged on the rear side of the heat sink3. The heat sink3is configured such that the movement thereof along arrow Y1 is restricted by a restriction portion22formed on the Y1 side of the rear frame2, as shown inFIG. 2. The LED substrate fixing portion32is an example of the “light source substrate fixing portion” in the present invention. The heat sink body portion31is an example of the “bottom surface” in the present invention.

The LED module4mainly includes the LED substrate41and the plurality of LEDs42mounted on the LED substrate41, as shown inFIGS. 2,3,5, and6. The LEDs42are configured to supply light to the display portion10(seeFIG. 1). The LED module4is arranged on the right side (Y1 side) when the TV body100a(seeFIG. 1) is viewed from the front side. The plurality of LEDs42are provided in the extensional direction (direction Z) of the LED substrate41. In other words, the plurality of LEDs42are arranged in the vertical direction (direction Z) of the TV100on the LED substrate41. As shown inFIG. 2, the LED substrate41is provided with spacers43for keeping an interval between the LEDs42and a light incident surface81aof the light guide plate8constant. The spacers43are provided in the vicinity of both ends of the LED substrate41in the direction Z.

According to this embodiment, the LED substrate41has a substantially rectangular section, as shown inFIGS. 3 and 5. The LED substrate41includes a front end surface411pressed by a plurality of substrate pressing portions92described later and the rear end surface412opposite (X2 side) to the front end surface411. The front end surface411and the rear end surface412of the LED substrate41are flattened. A surface of the LED substrate41on the Y1 side is attached to a surface of the LED substrate fixing portion32of the heat sink3on a Y2 side by the double-faced adhesive tape5. The single LED substrate41is provided along one side of the edge of the substantially rectangular TV body100a(the right side (Y1 side) as viewed from the front side (X1 side) of the TV body100a), as shown inFIG. 2.

According to this embodiment, the double-faced adhesive tape5is configured to fix the LED module4to the heat sink3, as shown inFIGS. 2,3, and5. The double-faced adhesive tape5is provided behind (Y1 side) the LED substrate41of the LED module4. The double-faced adhesive tape5is attached to a position of the LED substrate41separated by a prescribed interval from the rear end surface412of the LED substrate41. The double-faced adhesive tape5includes metal (aluminum, for example) having good thermal conductivity in order to improve heat release property. The double-faced adhesive tape5has a thickness t (0.5 mm, for example) sufficient for shear-deformation in a direction (direction X) toward the heat sink3(heat sink body portion31), as shown inFIG. 5.

According to this embodiment, the cushion6is arranged on the rear side (X2 side) of the light guide plate8, as shown inFIG. 3. The cushion6has a substantially rectangular section in the direction Z. The cushion6is configured to support the light guide plate8toward the front side (X1 side). The cushion6is made of a material (such as urethane foam) absorbing a shock. The cushion6is an example of the “elastic member” in the present invention.

As shown inFIG. 3, the reflective sheet7asuppressing light leakage to the rear side (X2 side) of the light guide plate8is provided on the rear side of the light guide plate8. The reflective sheet7ais arranged between the light guide plate8and the cushion6. The optical sheet7befficiently transmitting light emitted from the light guide plate8to the display portion10is provided on the front side (X1 side) of the light guide plate8.

According to this embodiment, the light guide plate8has a function of guiding light to the display portion10. As shown inFIG. 2, the light guide plate8has a substantially rectangular shape. The light guide plate8has the light incident surface81areceiving light emitted from the LEDs42and a light emitting surface81bemitting the light, as shown inFIGS. 2 and 3. Specifically, the light guide plate8is arranged on the rear side (X2 side) of the display portion10(seeFIG. 1) to be opposed to the LED substrate41mounted with the LEDs42and has the light incident surface81aincluding a side surface receiving the light emitted from the LEDs42. The light incident surface81ais opposed to the LEDs42. The light emitting surface81bis provided on the front side (X1 side) of the light guide plate8, as shown inFIG. 3. The light emitting surface81bis provided to extend in a direction (direction Y) substantially perpendicular to the light incident surface81a. The light incident surface81ahas a width W substantially equal to that of each of light irradiation portions421of the LEDs42in the direction X. Furthermore, the light incident surface81asubstantially faces the light irradiation portions421of the LEDs42in the direction X.

According to this embodiment, the resin frame9includes the holes91, the substrate pressing portions92, and a light guide plate pressing portion93, as shown inFIG. 4. The resin frame9is configured to fix the light guide plate8to a prescribed position, as shown inFIG. 3. The holes91are configured to engage with the claw portions21of the rear frame2. As shown inFIG. 4, the substrate pressing portions92and the light guide plate pressing portion93are formed integrally with the resin frame9. Furthermore, the substrate pressing portions92and the light guide plate pressing portion93are formed on an inner surface on the X2 side. As shown inFIG. 3, the substrate pressing portions92and the light guide plate pressing portion93are configured to press the front end surface411of the LED substrate41and the front surface (a part of the light emitting surface81b) of the light guide plate8, respectively, in a direction (along arrow X2) toward the heat sink3(heat sink body portion31) in a surface contact state. The holes91are examples of the “first engaging portion” in the present invention. The claw portions21are examples of the “second engaging portion” in the present invention.

The plurality of substrate pressing portions92are formed to extend along the extensional direction (direction Z) of the front end surface411(seeFIG. 2) of the LED substrate41, as shown inFIG. 4. Portions92a(seeFIG. 3) of the substrate pressing portions92pressing the front end surface411of the LED substrate41are flattened. Each of the substrate pressing portions92is in the form of a rib. The plurality of substrate pressing portions92are formed at prescribed intervals along the extensional direction (direction Z) of the LED substrate41in a position corresponding to the front end surface411of the LED substrate41. The substrate pressing portions92are configured to press the front end surface411of the LED substrate41attached to the LED substrate fixing portion32in the direction (along arrow X2) toward the heat sink3(heat sink body portion31) in the surface contact state, as shown inFIG. 3. The front end surface411of the LED substrate41is pressed in the direction toward the heat sink3(heat sink body portion31), whereby the rear end surface412of the LED substrate41comes into surface contact with the heat sink3. The holes91of the resin frame9and the claw portions21of the rear frame2engage with each other, whereby the front end surface411of the LED substrate41is pressed in the surface contact state by the substrate pressing portions92while held between the resin frame9and the rear frame2. As shown inFIG. 2, the holes91and the claw portions21engage with each other, whereby the movement of the resin frame9and the rear frame2in a direction (direction X) separating from each other is restricted. The substrate pressing portions92are provided in a position corresponding to the front end surface411of the single LED substrate41on one side (a side in the direction Y) of the edge of the TV body100a.

The light guide plate pressing portion93is formed to extend along the extensional direction (direction Z) of the front end surface411(seeFIG. 2) of the LED substrate41, as shown inFIG. 4. A portion93a(seeFIG. 3) of the light guide plate pressing portion93pressing the light guide plate8is flattened. The light guide plate pressing portion93is in the form of a rib. The light guide plate pressing portion93is configured to press the front surface (a part of the light emitting surface81b) of the light guide plate8in the direction (along arrow X2) toward the heat sink3(heat sink body portion31) in a surface contact state, as shown inFIG. 3. The light guide plate8is configured to be supported from the rear side (X2 side) toward the front side (X1 side) by the cushion6while the front side (X1 side) thereof is pressed in the direction toward the heat sink3(heat sink body portion31). Furthermore, the light guide plate8is configured to be supported through the reflective sheet7afrom the rear side toward the front side by the cushion6while the front side (the side (X1 side) of the light emitting surface81b) of the light guide plate8is pressed in the direction (along arrow X2) toward the heat sink body portion31. The cushion6is provided in a position corresponding to the light guide plate pressing portion93. The holes91of the resin frame9and the claw portions21of the rear frame2engage with each other, whereby the front surface of the light guide plate8is pressed by the light guide plate pressing portion93while held between the resin frame9and the rear frame2.

As shown inFIGS. 3 and 5, the front end surfaces422of the LEDs42are aligned with the light emitting surface81bof the light guide plate8in the direction X in a state where the substrate pressing portions92and the light guide plate pressing portion93press the front end surface411of the LED substrate41and the front surface (a part of the light emitting surface81b) of the light guide plate8, respectively, along arrow X2. The respective light irradiation portions421of the plurality of LEDs42are opposed to the light incident surface81aof the light guide plate8in a state where the front end surface411of the LED substrate41attached to the LED substrate fixing portion32is pressed in the direction (along arrow X2) toward the heat sink body portion31by the substrate pressing portions92. The front end surface411of the LED substrate41is pressed by the substrate pressing portions92, whereby the double-faced adhesive tape5is shear-deformed in the direction (along arrow X2) toward the heat sink3(heat sink body portion31) in a state where the rear end surface412is moved to come into contact with the heat sink3. The double-faced adhesive tape5is configured to maintain adhesion between the LED substrate41and the heat sink3when the double-faced adhesive tape5is shear-deformed. The double-faced adhesive tape5is configured to maintain adhesion of the LED substrate41to the heat sink3when the double-faced adhesive tape5is shear-deformed in the direction toward the heat sink body portion31.

A procedure for mounting the LED substrate41is now described with reference toFIGS. 2,3,5, and6. First, the LED substrate41is mounted on the LED substrate fixing portion32of the heat sink3through the double-faced adhesive tape5. At this time, the LED substrate41is turned toward the LED substrate fixing portion32, employing a corner412aof the rear end surface412of the LED substrate41as a supporting point while the corner412acomes into contact with the LED substrate fixing portion32, as shown inFIG. 6. Then, the LED substrate41is attached to the heat sink3(LED substrate fixing portion32) by the double-faced adhesive tape5. Then, the rear frame2is arranged on the rear side of the heat sink3mounted with the LED substrate41, as shown inFIG. 2. Then, the cushion6is arranged on the front side (X1 side) of the heat sink3, as shown inFIG. 3. Then, the reflective sheet7a, the light guide plate8, and the optical sheet7bare arranged on the heat sink3in this order from the rear side (X2 side). In this state, the resin frame9is mounted on the rear frame2from the front side, whereby the front end surface411of the LED substrate41and the front surface (a part of the light emitting surface81b) of the light guide plate8are pressed in the direction (along arrow X2) toward the heat sink3(heat sink body portion31) in the surface contact state by the substrate pressing portions92and the light guide plate pressing portion93, respectively. Thus, the double-faced adhesive tape5is shear-deformed in the direction (along arrow X2) toward the heat sink3(heat sink body portion31) in the state where the rear end surface412of the LED substrate41is moved to come into contact with the heat sink3, as shown inFIG. 5.

According to this embodiment, as hereinabove described, the TV100is provided with the substrate pressing portions92pressing the front end surface411of the LED substrate41in the direction toward the heat sink body portion31in the surface contact state. Thus, the front end surface411of the LED substrate41attached to the LED substrate fixing portion32can be brought into surface contact with the substrate pressing portions92to be pressed with force only in the direction toward the heat sink body portion31by the substrate pressing portions92, and hence sufficient pressing force to move the LED substrate41toward the heat sink body portion31can be obtained, and the front end surface411of the LED substrate41can be stably pressed due to surface contact. Therefore, the separation (positional displacement) of the LED substrate41from the heat sink body portion31can be sufficiently modified even when the LED substrate41is attached while separated (positionally displaced) toward the front side. Consequently, positional displacement between the light incident surface81aof the light guide plate8and the LEDs42can be suppressed, and hence a reduction in the quantity of light incident on the light guide plate8can be suppressed. Furthermore, a reduction in the quantity of light incident on the light guide plate8can be suppressed, and hence a reduction in luminance of light emitted from the light guide plate8can be suppressed.

According to this embodiment, as hereinabove described, the front end surface411of the LED substrate41is flattened, and the portions92aof the substrate pressing portions92pressing the front end surface411of the LED substrate41are flattened. Thus, the front end surface411of the LED substrate41can be easily pressed while coming into surface contact with the portions92aof the substrate pressing portions92pressing the front end surface411to be stabilized.

According to this embodiment, as hereinabove described, the plurality of substrate pressing portions92are provided at the prescribed intervals along the extensional direction of the LED substrate41in the position corresponding to the front end surface411of the LED substrate41. Thus, the entire front end surface411of the LED substrate41can be easily pressed by the plurality of substrate pressing portions92.

According to this embodiment, as hereinabove described, the LED substrate fixing portion32is formed by bending a part of the heat sink3made of metal frontward, and the front end surface411of the LED substrate41is pressed in the direction toward the heat sink body portion31so that the rear end surface412of the LED substrate41comes into contact with the heat sink3. Thus, the LED substrate41can be accurately positioned by being held between the substrate pressing portions92and the heat sink3, and hence positional displacement between the light incident surface81aof the light guide plate8and the LEDs42can be effectively suppressed.

According to this embodiment, as hereinabove described, the rear end surface412of the LED substrate41is flattened, and the portion of the heat sink3coming into contact with the rear end surface412of the LED substrate41is flattened. Thus, the rear end surface412of the LED substrate41and the portion of the heat sink3coming into contact with the rear end surface412of the LED substrate41can be brought into contact with each other in a stable state, and hence the front end surface411of the LED substrate41can be more stably pressed by the substrate pressing portions92.

According to this embodiment, as hereinabove described, the light irradiation portions421of the LEDs42are opposed to the light incident surface81aof the light guide plate8in the state where the front end surface411of the LED substrate41attached to the LED substrate fixing portion32is pressed in the direction toward the heat sink body portion31by the substrate pressing portions92. Thus, light emitted from the light irradiation portions421of the LEDs42can be guided to the light incident surface81aof the light guide plate8in a state where the separation (positional displacement) of the LED substrate41from the heat sink body portion31is modified, and hence a reduction in the quantity of light incident on the light guide plate8can be further suppressed.

According to this embodiment, as hereinabove described, the double-faced adhesive tape5is shear-deformed in the direction toward the heat sink body portion31in the state where the front end surface411of the LED substrate41is pressed by the substrate pressing portions92so that the rear end surface412of the LED substrate41is moved to come into contact with the heat sink3. Thus, the separation (positional displacement) of the LED substrate41from the heat sink3can be modified while the adhesive effect of the LED substrate41on the LED substrate fixing portion32is maintained when the front end surface411of the LED substrate41is pressed by the substrate pressing portions92.

According to this embodiment, as hereinabove described, the double-faced adhesive tape5is configured to maintain adhesion of the LED substrate41to the heat sink3when the double-faced adhesive tape5is shear-deformed in the direction toward the heat sink body portion31. Thus, the separation of the LED substrate41from the heat sink3can be modified while the adhesive effect of the LED substrate41on the LED substrate fixing portion32is reliably maintained.

According to this embodiment, as hereinabove described, the double-faced adhesive tape5is attached to the position of the LED substrate41separated by the prescribed interval from the rear end surface412of the LED substrate41. Thus, utilizing the interval between the position of the attached double-faced adhesive tape5and the rear end surface412of the LED substrate41, the LED substrate41can be moved to modify the separation of the LED substrate41from the heat sink3when the double-faced adhesive tape5is shear-deformed. Thus, sufficient pressing force to move the LED substrate41toward the heat sink body portion31can be easily obtained.

According to this embodiment, as hereinabove described, the double-faced adhesive tape5has the thickness sufficient for shear deformation in the direction toward the heat sink body portion31. Thus, the double-faced adhesive tape5can be easily shear-deformed in the direction toward the heat sink body portion31.

According to this embodiment, as hereinabove described, the TV100is provided with the resin frame9configured to fix the light guide plate8, arranged on the front side of the LED substrate41, and the substrate pressing portions92are integrally formed on the resin frame9to extend along the extensional direction of the front end surface411of the LED substrate41. Thus, an increase in the number of components can be suppressed. Furthermore, a contact area between the substrate pressing portions92and the front end surface411of the LED substrate41can be increased by the substrate pressing portions92extending along the extensional direction of the front end surface411of the LED substrate41, and hence the front end surface411of the LED substrate41can be pressed in a more stable state.

According to this embodiment, as hereinabove described, the TV100is provided with the rear frame2on the rear side of the heat sink3, the holes91are formed in the resin frame9, and the claw portions21engaging with the holes91are formed on the rear frame2. Furthermore, the substrate pressing portions92are configured to press the front end surface411of the LED substrate41while the holes91and the claw portions21engage with each other so that the front end surface411of the LED substrate41is held between the resin frame9and the rear frame2. Thus, the front end surface411of the LED substrate41can be pressed by the substrate pressing portions92simultaneously when the resin frame9is mounted on the rear frame2, and hence an assembly operation can be simplified.

According to this embodiment, as hereinabove described, the holes91and the claw portions21engage with each other so that the movement of the resin frame9and the rear frame2in the direction separating from each other is restricted. Thus, an interval between the resin frame9and the rear frame2engaging with each other can be maintained constant, and hence a state of holding the LED substrate41between the resin frame9and the rear frame2can be easily maintained.

According to this embodiment, as hereinabove described, the cushion6is arranged on the rear side of the light guide plate8, the substrate pressing portions92and the light guide plate pressing portion93are formed to press the front end surface411of the LED substrate41and the front surface of the light guide plate8, respectively, in the direction toward the heat sink body portion31in the surface contact state, the rear end surface412of the LED substrate41comes into contact with the heat sink3in the state where the front end surface411of the LED substrate41is pressed in the direction toward the heat sink body portion31, and the light guide plate8is configured to be supported from the rear side by the cushion6while pressed in the direction toward the heat sink body portion31. Thus, the movement of the front end surface411of the LED substrate41and the front surface of the light guide plate8in a direction opposite to the direction toward the heat sink3can be restricted by the substrate pressing portions92and the light guide plate pressing portion93, respectively, and the light guide plate8can be supported toward the front side by the cushion6and be positioned while the LED substrate41is held between the substrate pressing portions92and the heat sink3and is positioned. Thus, positional displacement between the light incident surface81aof the light guide plate8and the LEDs42can be more accurately suppressed.

According to this embodiment, as hereinabove described, the reflective sheet7ais arranged between the light guide plate8and the cushion6, and the light guide plate8is configured to be supported through the reflective sheet7afrom the rear side toward the front side by the cushion6while the front side of the light guide plate8is pressed in the direction toward the heat sink body portion31. Thus, light leakage from the light guide plate8to the rear side can be suppressed, the movement of the front end surface411of the LED substrate41and the front surface of the light guide plate8in the direction opposite to the direction toward the heat sink body portion31can be restricted by the substrate pressing portions92and the light guide plate pressing portion93, respectively, and the light guide plate8can be supported toward the front side by the cushion6and be positioned while the LED substrate41is held between the substrate pressing portions92and the heat sink3and is positioned.

According to this embodiment, as hereinabove described, the TV body100ahas the substantially rectangular shape as viewed from the front side, and the single LED substrate41is provided along one side of the edge of the substantially rectangular TV body100a. Furthermore, the substrate pressing portions92are provided in the position corresponding to the front end surface411of the single LED substrate41on one side of the edge of the TV body100a. Thus, a reduction in the pressing force of the substrate pressing portions92pressing the LED substrate41can be suppressed, unlike the case where a plurality of LED substrates41and a plurality of substrate pressing portions92are provided along a plurality of sides of the edge of the substantially rectangular TV body100a, for example. Consequently, sufficient pressing force to move the LED substrate41toward the heat sink body portion31can be easily obtained.

According to this embodiment, as hereinabove described, the plurality of LEDs42are provided in the extensional direction of the LED substrate41, and the respective light irradiation portions421of the plurality of LEDs42are opposed to the light incident surface81aof the light guide plate8in the state where the front end surface411of the LED substrate41attached to the LED substrate fixing portion32is pressed in the direction toward the heat sink body portion31by the substrate pressing portions92. Thus, even when the LED substrate41provided with the plurality of LEDs42is attached while separated (positionally displaced) toward the front side, the front end surface411of the LED substrate41attached to the LED substrate fixing portion32can be brought into surface contact with the substrate pressing portions92to be pressed with force only in the direction toward the heat sink body portion31by the substrate pressing portions92, and hence positional displacement between the light incident surface81aof the light guide plate8and the plurality of LEDs42can be suppressed. Therefore, a reduction in the quantity of light incident on the light guide plate8from the plurality of LEDs42can be suppressed.

The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The range of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and all modifications within the meaning and range equivalent to the scope of claims for patent are further included.

For example, while the present invention is applied to the TV (television set) as the display device in the aforementioned embodiment, the present invention is not restricted to this. The present invention is also applicable to another display device such as a monitor of a PC (personal computer).

While the front side of the heat sink is flattened in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, a concave portion104may alternatively be provided in a position of the front side of the heat sink corresponding to the rear end surface of the light source substrate, as shown inFIG. 7. Specifically, the rear end surface of the light source substrate is fitted into the concave portion104provided in the position of the heat sink corresponding to the rear end surface of the light source substrate. Thus, the separation (positional displacement) of the light source substrate from the heat sink can be modified while the movement (displacement) of the rear end surface of the light source substrate in a direction toward the light guide plate (a direction perpendicular to a direction separating the light source substrate from the heat sink) is suppressed by bringing the rear end surface of the light source substrate into contact with the concave portion104. Therefore, positional displacement between the light incident surface of the light guide plate and the light source can be more effectively suppressed. In this case, an inclination portion105may alternatively be formed on the corner of the concave portion104closer to the light guide plate. Thus, the rear end surface of the light source substrate can be guided by the inclination portion105when the front end surface of the light source substrate attached to the light source substrate fixing portion is pressed in the direction toward the heat sink in a surface contact state, and hence the rear end surface of the light source substrate can be smoothly brought into contact with the heat sink (a bottom portion of the concave portion104).

While the plurality of substrate pressing portions are provided at the prescribed intervals in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, the plurality of substrate pressing portions may alternatively be provided at irregular intervals. Alternatively, a single substrate pressing portion extending from one end to the other end along the extensional direction of the front end surface of the light source substrate may be provided.

While the substrate pressing portions and the light guide plate pressing portion are provided on the resin frame in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, the substrate pressing portions and the light guide plate pressing portion may alternatively be provided on a member other than the resin frame.

While each of the substrate pressing portions is in the form of a rib in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, each of substrate pressing portions192may alternatively have a shape (L-sectional shape, for example) having a function of a elastically deformable resin spring, for example, other than the form of a rib, as shown inFIG. 8. Thus, the substrate pressing portions192are deflection-deformed so that pressing force applied to the light source substrate can be adjusted. Therefore, proper pressing force can be applied to the light source substrate.

While the first engaging portion according to the present invention includes the holes and the second engaging portion according to the present invention includes the claw portions in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, the first engaging portion may alternatively include the claw portions, and the second engaging portion may alternatively include the holes. Alternatively, the first engaging portion and the second engaging portion may be in the form of hooks corresponding to each other.

While the double-faced adhesive tape having a thickness of 0.5 mm is employed in the aforementioned embodiment, the present invention is not restricted to this. According to the present invention, a double-faced adhesive tape having a thickness other than 0.5 mm may alternatively be employed so far as the double-faced adhesive tape can be shear-deformed in a direction toward the bottom surface of the heat sink.