JP2005352427A - Liquid crystal display device and back light device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply the display light emitted from a light source block in a uniform state to a liquid crystal panel. <P>SOLUTION: The display light emitted from an LED 12 of the light source block 11 is supplied to a transmission type liquid crystal panel 5 in a uniform state by an optical sheet block 10. A diffusion light guide plate 14, diffusion plate 15 and reflection plate 16 of the optical sheet block 10 are positioned relatively to each other by a plurality of optical stud members 17 attached to a back panel 9 and are held by regulating opposed interval. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmissive liquid crystal display (LCD) and a backlight device suitably used for the liquid crystal display.

  The liquid crystal display device has a larger display screen, lighter weight, thinner thickness, lower power consumption, etc., compared with a cathode ray tube (CRT), for example, a self-luminous PDP (Plasma Display). Panel) and the like are used for television receivers and various displays. A liquid crystal display device encapsulates liquid crystal between two transparent substrates of various sizes and changes the light transmittance by changing the direction of liquid crystal molecules by applying a voltage to optically display a predetermined image or the like. To do.

  The liquid crystal display device includes a backlight device that supplies display light to the back side of the liquid crystal panel, for example, because the liquid crystal itself is not a light emitter. The backlight device includes, for example, a light source, a light guide plate, a reflection film, a lens sheet, or a diffusion film, and supplies display light emitted from the light source to the entire liquid crystal panel. In the backlight device, a cold cathode fluorescent lamp (CCLF: Cold Cathode Fluorescent Lamp) in which mercury or xenon is enclosed in a fluorescent tube as a conventional light source has been used. There has been a problem to solve problems such as brightness, lifetime, or uniformity due to the presence of a low-luminance region on the cathode side.

  By the way, in a large-sized liquid crystal display device, an area light type backlight (area light backlight) that generally arranges a plurality of long cold-cathode fluorescent lamps as a light source on the back of a diffusion plate and supplies display light to a liquid crystal panel. ) Equipment is provided. Even in such area light type backlight devices, there is a demand for solving the problems of the above-mentioned cold cathode fluorescent lamps, and particularly in large television receivers exceeding 40 inches, there are problems of high brightness and high uniformity. Has become more prominent.

  On the other hand, in the area light type backlight device, instead of the cold cathode fluorescent lamp described above, a large number of light emitting diodes (LED: Light Emitting Diodes) that emit light of three primary colors of red, green, and blue on the back side of the diffusion film. ) Are two-dimensionally arranged to obtain white light, and LED area light type backlights are attracting attention. Such an LED backlight device is designed to reduce the cost as the cost of the LED is reduced and to display a high luminance on a large liquid crystal panel with a low power consumption type.

  By the way, the backlight device is provided with an optical sheet block which is installed on the back side of the liquid crystal panel and performs predetermined optical processing on the display light emitted from the light source block and supplies it with uniform illuminance over the entire surface. ing. The optical sheet block is formed by laminating various optical functional sheets such as a polarizing film, a retardation film, a prism sheet, or a diffusion film, and is a polarizing component that orthogonalizes display light supplied from a light emitting unit and incident on a liquid crystal panel. A plurality of optical function sheets having various optical functions, such as a functional sheet that decomposes into two, a functional sheet that compensates for the phase difference of the light wave to prevent a wide-angle viewing angle and prevent coloring, or a functional sheet that diffuses display light. It has a structured optical function sheet laminate.

  The optical sheet block includes a diffusion light guide plate formed of a synthetic resin material such as an acrylic resin or a polycarbonate resin having milky white light guide property. The diffusion light guide plate guides the display light incident from one main surface side while diffusing and reflecting the light in the layer, and makes the light enter the optical function sheet laminate from the other main surface side. The optical sheet block is formed of, for example, a synthetic resin material such as a transparent acrylic resin, and includes a diffusion plate that transmits a part of the display light emitted from the light source and reflects a part thereof. The diffuser plate prevents the occurrence of color unevenness by making the display light uniform and suppressing the generation of a high luminance region partially. The optical sheet block includes a reflection sheet that causes display light emitted from the light source to the surroundings and display light reflected by the diffusion plate to enter the diffusion light guide plate again. The reflection sheet improves the reflectivity by the principle of increasing reflection by repeatedly reflecting the display light between the diffuser plate and efficiently supplies the display light to the liquid crystal panel.

  In the backlight device, the various optical sheets of the optical sheet block must be disposed between the liquid crystal panel and the light source block with the mutually facing distance being precisely positioned. In the backlight device, in order to prevent the occurrence of color unevenness and the like, the optical sheets are arranged with a high accuracy in the distance between each other, and the display light is uniformly and stable over the entire area with respect to the liquid crystal panel. Need to be supplied at. In a backlight device, it is extremely important to position each optical sheet with high accuracy when a large display screen is used and a large number of LEDs are used as a light source to achieve high brightness.

  In the backlight device, a positioning structure and a spacing structure have been provided in order to position and combine the optical sheets of the optical sheet block with high accuracy with respect to the liquid crystal panel and the light source block. For this reason, the backlight device has a problem that the structure is complicated, the number of parts and the number of assembly steps are increased, the cost is increased, and it is difficult to reduce the thickness, weight, and size. Further, in the backlight device, since each optical sheet is laminated through a positioning structure and a spacing structure provided respectively, the entire optical sheet is caused by variations in dimensional accuracy and assembly accuracy of the constituent members. There was a problem that variation in dimensional accuracy was large. Further, in the backlight device, when the display sizes are different, there is a problem in that the members are not used in common, and enormous mold costs and management costs are required, thereby increasing the overall cost.

  Therefore, according to the present invention, a plurality of optical members constituting the optical sheet block are assembled with high accuracy by a simple structure and process, and display light emitted from the light source block is spread over the entire surface of the transmissive liquid crystal panel. It is an object of the present invention to provide a liquid crystal display device that can guide light in a uniform state and prevent occurrence of color unevenness.

  In addition, the present invention provides an optical sheet block that can be assembled with high accuracy by a simple structure and process, thereby guiding display light emitted from the light source block to the transmissive liquid crystal panel in a uniform state over the entire surface. An object of the present invention is to provide a backlight device that emits light.

  A liquid crystal display device according to the present invention that achieves the above-described object includes a transmissive liquid crystal panel, a light source block that has a light source that emits display light and is attached to the back panel, an optical functional sheet laminate, and a diffusion light guide. A plate, a diffusion plate, a reflective sheet, and a plurality of optical stud members are provided. The optical functional sheet laminate is formed by laminating various optical functional sheets such as a polarizing film, a retardation film, a prism sheet, or a diffusion film, and is disposed on the back side of the transmissive liquid crystal panel to optically display light. The function is converted and guided to the transmissive liquid crystal panel. The diffusion light guide plate is disposed on the back side of the optical functional sheet laminate so as to face the transmissive liquid crystal panel and diffuses the incident display light in the layer to cover the entire surface of the optical functional sheet laminate. And supply in a uniform state. The diffusion plate is opposed to the diffusion light guide plate with a predetermined facing interval, and transmits part of the display light emitted from the light source block and reflects part of it. The reflection sheet is disposed opposite to the back side of the diffusion plate with a predetermined interval, and reflects the display light emitted from the light source block to the surroundings and the display light reflected by the diffusion plate to the diffusion plate side.

  Each optical stud member is attached to the back panel and defines a facing distance between the diffusion plate and the reflection sheet. Each optical stud member is formed on the back panel by forming an axial base portion having an axial length that defines an interval between the back panel and the diffusion light guide plate, and a base end portion of the axial base portion. A fitting portion that is attached to the attachment portion, a first receiving plate portion that protrudes from the fitting portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the reflection sheet, and the first receiving portion. From the second receiving plate portion, a second receiving plate portion that is formed to protrude from the plate portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the diffusion plate at a predetermined facing interval with respect to the reflection sheet. A thin step portion formed at a height position substantially equal to the thickness of the diffusion plate is integrally formed of a light guide resin material. Each optical stud member is attached to the back panel, and the diffusion light guide plate is brought into contact with the tip of the shaft-like base portion to be combined with each other, so that the facing distance between the diffusion light guide plate, the diffusion plate, and the reflection sheet is precise. And a light guide space is formed between the diffusion plate and the diffusion light guide plate.

  In the liquid crystal display device, each optical stud member is fixed by fitting its respective fitting portion into the opposite mounting hole of the back panel, so that the reflective sheet is sandwiched between the fitting portion and the mounting portion. Position and hold on the panel. In the liquid crystal display device, the diffusion plate and the reflection sheet are held at a predetermined facing distance by locking the diffusion plate in which each optical stud member is combined with the respective shaft-like base portions with the second receiving plate portion. So that In the liquid crystal display device, each optical stud member is positioned by preventing the diffusion plate locked by each second receiving plate portion from being raised by each step portion. In the liquid crystal display device, each optical stud member is made to abut the diffusion light guide plate at the tip portion thereof, so that the facing distance between the diffusion light guide plate and the diffusion plate is maintained.

  In the liquid crystal display device, a part of the display light emitted from each light source of the light source block is transmitted by the diffusion plate and guided to the diffusion light guide plate through the light guide space. In a liquid crystal display device, a part of display light is reflected on the diffusion plate to suppress the generation of a partial high brightness region, and the diffusion light guide plate is in a state where the display light is almost uniform from the entire surface of the diffusion plate. To be guided to. In the liquid crystal display device, display light guided between the reflection plate, the diffusion plate, and the diffusion light guide plate precisely positioned by each optical stud member is transmitted to the transmission type liquid crystal panel through the optical function sheet laminate. The transmissive liquid crystal panel is optically displayed.

  In addition, the backlight device according to the present invention that achieves the above-described object includes a light source block that has a light source that emits display light and is attached to the back panel, an optical function sheet laminate, a diffusion light guide plate, and a diffusion. A plate, a reflection sheet, and a plurality of optical stud members are provided, and display light arranged on the back side of the transmissive display panel and emitted from the light source block is supplied to the transmissive display panel for optical display. Like that.

  The optical functional sheet laminate is formed by laminating various optical functional sheets such as a polarizing film, a retardation film, a prism sheet, or a diffusion film, and is disposed on the back side of the transmissive liquid crystal panel to optically display light. The function is converted and guided to the transmissive liquid crystal panel. The diffusion light guide plate is disposed on the back side of the optical functional sheet laminate so as to face the transmissive liquid crystal panel, and diffuses display light to enter the entire surface of the optical functional sheet laminate. The diffusion plate is opposed to the diffusion light guide plate with a predetermined facing interval, and transmits part of the display light emitted from the light source block and reflects part of it. The reflection sheet is disposed opposite to the back side of the diffusion plate with a predetermined interval, and reflects the display light emitted from the light source block to the surroundings and the display light reflected by the diffusion plate to the diffusion plate side.

  Each optical stud member is attached to the back panel and defines a facing distance between the diffusion plate and the reflection sheet. Each optical stud member is formed on the back panel by forming an axial base portion having an axial length that defines an interval between the back panel and the diffusion light guide plate, and a base end portion of the axial base portion. A fitting portion that is attached to the attachment portion, a first receiving plate portion that protrudes from the fitting portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the reflection sheet, and the first receiving portion. From the second receiving plate portion, a second receiving plate portion that is formed to protrude from the plate portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the diffusion plate at a predetermined facing interval with respect to the reflection sheet. A thin step portion formed at a height position substantially equal to the thickness of the diffusion plate is integrally formed of a light guide resin material. Each optical stud member forms a light guide space portion between the optical stud member and the diffusion plate by being combined with the light guide plate being abutted against the distal end portion of the shaft-like base portion while being attached to the back panel.

  In the backlight device, each optical stud member is fixed by fitting its respective fitting portion into the opposite mounting hole of the back panel, so that the reflective sheet is sandwiched between the fitting portion and the mounting portion. Position and hold on the panel. In the backlight device, the diffusion plate and the reflection sheet are held at a predetermined facing interval by locking the diffusion plate in which each optical stud member is combined with the respective shaft-like base portions with the second receiving plate portion. So that In the backlight device, each optical stud member is positioned by preventing the diffusion plate locked by each second receiving plate portion from being raised by each step portion. In the backlight device, each optical stud member is made to abut the diffusion light guide plate at the tip thereof, so that the facing distance between the diffusion light guide plate and the diffusion plate is maintained.

  In the backlight device, a part of the display light emitted from each light source of the light source block is transmitted by the diffusion plate and guided to the diffusion light guide plate through the light guide space. In the backlight device, a part of the display light is reflected on the diffusion plate to suppress the generation of a partial high brightness region, and the diffusion light guide plate is in a state where the display light is almost uniform from the entire surface of the diffusion plate. To be guided to. In the backlight device, display light guided between the reflecting plate, the diffusing plate, and the diffusing light guide plate precisely positioned by each optical stud member is transmitted to the transmissive liquid crystal panel through the optical function sheet laminate. To be supplied.

  As described above in detail, according to the present invention, the display light emitted from the light source of the light source block is guided by the plurality of optical stud members having a simple structure and assembled to the back panel by a simple method. The reflective plate, diffuser plate, and diffused light guide plate of the optical sheet block supplied to the transmissive liquid crystal panel can be positioned and combined at precise opposing intervals without the need for complicated positioning structures and spacing structures. Is possible. According to the present invention, the cost can be reduced by simplifying the structure and the assembly process, and the transmissive liquid crystal can perform predetermined operations such as light guide, diffusion, reflection and the like while the display light is stable in the light guide space. Since it is supplied to the panel, it is possible to prevent the occurrence of color unevenness and perform optical display such as a stable and precise image.

  Hereinafter, the transmissive liquid crystal display device 1 shown in the drawings as an embodiment of the present invention will be described in detail. The transmissive liquid crystal display device 1 is used for a display panel of a television receiver having a large display screen of, for example, 40 inches or more. As shown in FIGS. 1 and 2, the transmissive liquid crystal display device 1 includes a liquid crystal panel unit 2 and a backlight unit 3 that is combined with the back side of the liquid crystal panel unit 2 to supply display light. . The liquid crystal panel unit 2 includes a frame-shaped front frame member 4, a liquid crystal panel 5, and an outer peripheral edge portion of the liquid crystal panel 5 sandwiched between the front frame member 4 via spacers 2 </ b> A, 2 </ b> B, guide members 2 </ b> C, and the like. And a frame-like back frame member 6 held by

  Although not described in detail, the liquid crystal panel 5 encloses a liquid crystal between a first glass substrate and a second glass substrate, which are held at an opposing interval by spacer beads or the like, and applies a voltage to the liquid crystal to apply liquid crystal Change the light transmittance by changing the direction of the molecule. In the liquid crystal panel 5, a striped transparent electrode, an insulating film, and an alignment film are formed on the inner surface of the first glass substrate. In the liquid crystal panel 5, a color filter of three primary colors, an overcoat layer, a striped transparent electrode, and an alignment film are formed on the inner surface of the second glass substrate. In the liquid crystal panel 5, a deflection film and a retardation film are bonded to the surfaces of the first glass substrate and the second glass substrate.

  In the liquid crystal panel 5, an alignment film made of polyimide is arranged in a horizontal direction with liquid crystal molecules as an interface, and the deflection film and the retardation film achromatic and whiten the wavelength characteristics of the display light to make it full color with a color filter. The received image is displayed in color. In addition, about the liquid crystal panel 5, it is not limited to this structure, Of course, it may be a liquid crystal panel provided with the various structure provided conventionally.

  The backlight unit 3 is disposed on the back side of the liquid crystal panel unit 2 described above, emits display light from a light source, a heat dissipating unit 8 that dissipates heat generated in the light emitting unit 7, and these light emitting units. A back panel 9 that holds the unit 7 and the heat radiating unit 8 and constitutes a mounting member for the housing 33 (see FIG. 14) in combination with the front frame member 4 and the rear frame member 6 is provided. The backlight unit 3 has an outer dimension that is opposed to the entire back surface of the liquid crystal panel unit 2 and is combined in a state where the opposed space portions facing each other are optically sealed.

  In the backlight unit 3, the light emitting unit 7 includes an optical sheet block 10 and a light source block 11 having a number of light emitting diodes (hereinafter referred to as LEDs) 12 as light sources. The optical sheet block 10 is installed opposite to the back side of the liquid crystal panel 5, and details thereof are omitted. The functional sheet laminate 13, a diffusion light guide plate 14, a diffusion plate 15, a reflection sheet 16, and the like which will be described later.

  Although not described in detail, the optical functional sheet laminate 13 is a functional sheet that decomposes the display light supplied from the light source block 11 and supplied to the liquid crystal panel 5 into orthogonal polarization components, and compensates for the phase difference of the light wave to wide angle. A plurality of optical functional sheets having a predetermined optical function, such as a functional sheet for preventing viewing angle and preventing coloring, or a functional sheet for diffusing display light, are laminated. The optical function sheet laminate 13 is not limited to the above-described optical function sheet, and includes, for example, a brightness enhancement film for improving brightness, two upper and lower diffusion sheets sandwiching a retardation film and a prism sheet, and the like. May be.

  In the optical sheet block 10, as shown in FIG. 2, the diffusion light guide plate 14 is combined in a stacked state on the main surface side facing the liquid crystal panel 5 of the optical function sheet laminate 13 and supplied from the light source block 11. Light enters from the back side. The diffusion light guide plate 14 is made of a slightly thick plate body formed of a milky white synthetic resin material having a light guide property, such as an acrylic resin or a polycarbonate resin. The diffusion light guide plate 14 refracts, reflects, and diffuses display light incident from one main surface side to diffuse the light from the other main surface side in a uniform state over the entire surface. Incident light. As shown in FIG. 2, the diffusion light guide plate 14 is attached to the outer peripheral wall portion 9 a of the back panel 9 with the outer peripheral portion held by a bracket member 14 </ b> A.

  The optical sheet block 10 includes a back panel in which a diffusion plate 15 and a reflection sheet 16 are held by a plurality of optical stud members 17 whose details will be described later and the opposing distance between the diffusion light guide plate 14 described later. 9 is attached. The diffusion plate 15 is a plate material formed of a transparent synthetic resin material such as an acrylic resin, and the display light supplied from the light source block 11 is incident thereon. On the diffusion plate 15, a large number of light control dots 15 a are formed so as to be opposed to the large number of LEDs 12 of the light source block 11 arranged in an array as will be described in detail later.

  Each dimming dot 15a uses a reflective ink in which a light-shielding agent such as titanium oxide or barium sulfide or a diffusion agent such as glass powder or silicon oxide is mixed on the main surface of the diffusion plate 15 facing the light source block 11. It is formed by screen printing or the like. Each dimming dot 15a is formed of a substantially circular pattern having substantially the same diameter or a slightly larger diameter than the outer diameter of the LED 12 facing each other. In addition, you may make it each dimming dot 15a be comprised by the many dot pattern formed in the circular area | region slightly larger diameter than the outer diameter of LED12.

  The diffusion plate 15 reflects the display light supplied from the light source block 11 to the reflection sheet 16 side by the light control dots 15a and makes the light incident on a region where the light control dots 15a are not formed. The diffusing plate 15 regulates the amount of light incident on the facing portion of the display light emitted from each LED 12 by reflecting a component that is directly incident from directly below the light control dot 15a formed facing the LED 12. . The diffusion plate 15 equalizes the amount of emitted light by the light control dots 15a, and supplies the display light to the diffusion light guide plate 14 from the entire surface in a uniform state. The diffusion plate 15 reflects the display light emitted from each LED 12 and incident beyond the critical angle on the surface.

  In the optical sheet block 10, as described above, a part of the display light reflected by the light control dots 15 a and the display light radiated from each LED 12 to the surroundings are made incident on the diffusion plate 15 by the reflection sheet 16 to improve the light efficiency. Make improvements. The reflection sheet 16 is formed of, for example, a foamable PET (polyethylene terephthalate) material containing a fluorescent agent. The foamable PET material has a high reflectivity characteristic of about 95%, and has a characteristic that a scratch on the reflecting surface is not noticeable with a color tone different from the metallic luster color. The reflection sheet 16 is also formed of, for example, silver, aluminum, stainless steel or the like having a mirror surface.

  In the optical sheet block 10, reflected light from the surface of the diffusing plate 15 and part of the display light radiated from each LED 12 to the surroundings and reflected by the reflecting sheet 16 are between the diffusing plate 15 and the reflecting sheet 16. Make repeated reflections. The optical sheet block 10 repeatedly reflects display light between the diffusing plate 15 and the reflection sheet 16 so that the reflectance can be improved by the enhanced reflection principle.

  The optical sheet block 10 includes a plurality of optical stud members 17, and the optical stud members 17 accurately maintain the parallelism between the main surfaces of the diffusion plate 15 and the reflective sheet 16 facing each other. At the same time, the diffusion plate 15 and the diffusion light guide plate 14 are configured so that the parallelism between the main surfaces facing each other is accurately maintained over the entire surface. The optical stud member 17 is a member formed integrally with a milky white synthetic resin material having light guiding properties, mechanical rigidity, and a certain degree of elasticity, such as a polycarbonate resin, and is formed integrally with the back panel 9 as will be described later. Are fixed to the mounting portions 9a in a standing state.

  As shown in FIGS. 2 and 5, the back panel 9 is integrally formed with a large number of attachment portions 9 b having substantially trapezoidal convex portions on the inner surface side. In the back panel 9, the upper surface of the mounting portion 9 b constitutes a mounting surface for the reflection sheet 16, and mounting holes 9 c for mounting the optical stud member 17 are provided therethrough. The back panel 9 constitutes a mounting member for the housing 33 as described above, and the constituent members of the optical sheet block 10 are positioned and combined with each other via the optical stud members 17 on the first main surface 9d. A mounting member is configured.

  The diffusion plate 15 is formed with a plurality of fitting holes 15 b for assembling to each optical stud member 17. The reflective sheet 16 is also formed with a plurality of mounting holes 16 a that are formed to face the respective fitting holes 15 b of the diffusion plate 15 and are assembled to the respective optical stud members 17.

  As shown in FIG. 5, each optical stud member 17 has a shaft-like base portion 17a, a fitting portion 17b formed at the tip of the shaft-like base portion 17a, and a predetermined distance from the fitting portion 17b. A flange-shaped first receiving plate portion 17c integrally formed around the circumference of the shaft-shaped base portion 17a, and integrally formed around the circumference of the shaft-shaped base portion 17a with a predetermined distance from the first receiving plate portion 17c. And a flange-shaped second receiving plate portion 17d formed in the above. Each optical stud member 17 is formed with an axial length in which the axial base portion 17 a defines the facing distance between the mounting portion 9 b of the back panel 9 and the diffusion light guide plate 14. Each optical stud member 17 is formed with a stepped portion 17e on the shaft-like base portion 17a at a predetermined height position from the second receiving plate portion 17d.

  Each optical stud member 17 is formed such that the shaft-like base portion 17a has a long conical shape in which the stepped portion 17e has a larger diameter than the fitting hole 15b of the diffusion plate 15 and gradually becomes smaller in diameter toward the tip portion. Has been. Each optical stud member 17 is formed with an axial stealing hole 17f in the axial base portion 17a located slightly above the stepped portion 17e. The meat stealing hole 17f is formed in the shaft base 17a in a range of a portion whose outer diameter is larger than that of the fitting hole 15b of the diffusion plate 15, and imparts convergence to the formation portion.

  Each optical stud member 17 forms the first receiving plate portion 17c and the second receiving plate portion 17d with an interval that keeps the facing distance between the diffusion plate 15 and the reflection sheet 16. In each optical stud member 17, the shaft-like base portion 17 a forms the first receiving plate portion 17 c and the second receiving plate portion 17 d at the same diameter as the fitting hole 15 b of the diffusion plate 15. Each optical stud member 17 has a fitting portion 17b having an outer diameter of the tip portion substantially equal to the outer diameter of the mounting hole 9c on the back panel 9 side, and gradually becomes larger in diameter in the axial direction than the mounting hole 9c. The cross section is formed in a downward truncated cone shape. Each optical stud member 17 imparts convergence habit by forming a plurality of slits 17g from the large-diameter portion toward the tip side in the fitting portion 17b.

  Each optical stud member 17 has a fitting portion 17b formed so that the distance between the large-diameter portion and the first receiving plate portion 17b is substantially equal to the sum of the thickness of the back panel 9 and the thickness of the reflection sheet 16. . In each optical stud member 17, the first receiving plate portion 17 b has a larger diameter than the fitting hole 15 b of the diffusion plate 15, and the second receiving plate portion 17 d has a larger diameter than the mounting hole 16 a of the reflecting sheet 16. And is formed.

  In the optical sheet block 10, the reflective sheet 16 is combined with the mounting portion 9b of the back panel 9 with the mounting holes 9c and the mounting holes 16a facing each other. In the optical sheet block 10, each optical stud member 17 pushes its fitting portion 17b from the first main surface 9d side of the back panel 9 into the mounting hole 9c through the mounting hole 16a of the combined reflective sheet 16. It is. In the optical sheet block 10, the optical stud member 17 is prevented from coming off by the fitting portion 17b converging by the action of the slit 17g and returning to the natural state after passing through the mounting hole 9c on the back panel 9 side. And assembled in a standing state on the mounting portion 9b.

  In the optical sheet block 10, as shown in FIG. 5, each optical stud member 17 has the attachment portion 9b of the back panel 9 and the reflection sheet 16 in the thickness direction between the fitting portion 17b and the first receiving plate portion 17c. By clamping, the reflecting sheet 16 is fixed in a state of being positioned with respect to the back panel 9. In the optical sheet block 10, each optical stud member 17 is erected on the mounting portion 9 b of the back panel 9 with the upper portion protruding from the reflection sheet 16 from the first receiving plate portion 17 c of the axial base portion 17 a. The

  In the optical sheet block 10, the diffusion plate 15 is combined with each optical stud member 17 by inserting the respective fitting holes 15 b into the opposed tip portions 17 h. In the optical sheet block 10, each optical stud member 17 converges the large diameter portion by the action of the meat stealing hole 17 f, thereby enabling the diffusion plate 15 to be pushed in the axial direction. In the optical sheet block 10, the diffusion plate 15 gets over the stepped portion 17e and hits the second receiving plate portion 17d with respect to each optical stud member 17, and between the stepped portion 17e and the second receiving plate portion 17d. It is pinched.

  In the optical sheet block 10, as shown in FIGS. 4 and 5, each optical stud member 17 projects an upper part from the stepped portion 17 e of the axial base portion 17 a from the diffusion plate 15. In the optical sheet block 10, the diffusion light guide plate 14 on which the optical functional sheet laminate 13 is superimposed is assembled to the tip end portion 17 h of each optical stud member 17 so that the bottom surface side thereof is abutted.

  In the optical sheet block 10 configured as described above, a large number of optical stud members 17 are assembled on the first main surface 9d of the back panel 9 by a simple method of pushing the fitting portion 17b into the mounting hole 9c. It is done. In the optical sheet block 10, each optical stud member 17 positions the diffusion plate 15 and the reflection sheet 16, and the facing distance between the diffusion plate 15 and the reflection sheet 16 and the diffusion plate 15 and the diffusion light guide plate 14. Precisely define the spacing between the two. In the optical sheet block 10, each optical stud member 17 precisely defines the facing distance between the diffusion plate 15 and the optical function sheet laminate 13 via the diffusion light guide plate 14.

  The optical sheet block 10 includes the plurality of optical stud members 17 described above, thereby eliminating the need for complicated positioning structures and spacing structures, and simplifying the assembly process. In the optical sheet block 10, by using a large number of optical stud members 17 that have a simple structure and can be manufactured at a relatively low cost, it is possible to reduce component costs and assembly costs. In the optical sheet block 10, the optical stud member 17 can be used interchangeably with the liquid crystal panels 5 of various sizes, and parts can be shared.

  It should be noted that the optical stud member 17 is not limited to the above-described structure, and it is needless to say that the specific structure of each part is appropriately changed based on the configuration of the optical sheet block 10. The optical stud member 17 is attached by being pushed into the mounting hole 9c of the back panel 9 by, for example, forming the slit 17g of the fitting portion 17b and imparting convergence behavior. The stop convex portion may be formed integrally and fitted into the attachment hole 9c having a key groove on the inner peripheral portion, and then rotated to be prevented from coming off. The optical stud member 17 is formed by projecting the first receiving plate portion 17c and the second receiving plate portion 17d around the circumference at a predetermined interval with respect to the shaft-shaped base portion 17a. It is also possible to form a large-diameter portion in which the 17c and the second receiving plate portion 17d are integrated, and both end portions thereof constitute the receiving plate portion.

  In the optical sheet block 10, as described above, each of the constituent members 13, 14, 15, 16 is precisely positioned by the plurality of optical stud members 17, and the facing distance is defined. In the light guide space H formed between the reflective sheet 16 and the reflective sheet 16, operations such as light guide, diffusion, reflection and the like are performed in a stable state and supplied in a uniform state over the entire surface. As a result, the occurrence of color unevenness in the liquid crystal panel 5 is suppressed. In the optical sheet block 10, each optical stud member 17 provided in the light guide space portion H is formed of milky white light guide synthetic resin material, diffuses display light incident on the inside from its outer peripheral surface, and a tip portion 17h is formed. Try not to be partially brilliant.

  By the way, in the optical sheet block 10, as shown in FIG. 3, the optical stud member 17 described above is provided with five in the horizontal direction and three in the vertical direction, for a total of fifteen. The LEDs 12 are arranged between each row of light source blocks 11 described later in which six rows are arranged in the horizontal direction. Further, in the optical sheet block 10, the diffusion plate 15 and the reflection sheet 16 described above have different characteristics on the front and back surfaces, and must be combined without making a mistake.

  As described above, the diffusion plate 15 and the reflection sheet 16 are formed with a fitting hole 15b and a mounting hole 16a through which the shaft-like base portion 17a of the optical stud member 17 passes. The diffusion plate 15 and the reflection sheet 16 are formed with a total of 15 fitting holes 15b and attachment holes 16a corresponding to each optical stud member 17 in the horizontal direction and three in the vertical direction. In the optical sheet block 10, as shown in FIG. 3, the second optical stud member 17A from the left side of the lower row is placed on the back panel 9 at a different position from the second optical stud members 17 on the upper row side. Stand up. In the optical sheet block 10, the second fitting hole 15b and the mounting hole 16a from the left side of the lower row facing the optical stud member 17A are provided on the diffusion plate 15 and the reflection sheet 16, and the upper row of fitting holes 15b and the mounting holes. 16a is formed at a different position.

  Therefore, in the optical sheet block 10, even if the diffusing plate 15 and the reflection sheet 16 have the wrong front and back, they cannot be combined because the fitting hole 15b and the mounting hole 16a do not exist at the position facing the optical stud member 17A. By doing so, a miscombination prevention structure is configured. In the optical sheet block 10, the optical stud member 17 </ b> A, the diffusion plate 15, and the fitting hole 15 b and the attachment hole 16 a of the reflection sheet 16 constituting the erroneous combination prevention structure may be provided at any position other than the center position. Since the members are combined in a stable state, it is better to provide them at the inner position than at the outer peripheral position, and they may be provided at a plurality of places instead of one place.

  In the backlight unit 3, since the light emitting unit 7 includes the optical sheet block 10 described above, the display light emitted from each LED 12 of the light source block 11 is efficiently incident on the liquid crystal panel unit 2 in a stable state. So that As shown in FIG. 3, the light source block 11 includes six rows of light emitting arrays 11A to 11F arranged in the horizontal direction on the first main surface 9d of the back panel 9. The light source block 11 includes three light source block bodies (18A to 18C) A to (18A to 18C) F, which will be described in detail later, in which the light emitting arrays 11A to 11F are arranged in the length direction. Thus, a total of 18 light source block bodies 18 are provided. Note that the light source block bodies (18A to 18C) A to (18A to 18C) F are collectively referred to as the light source block body 18 except when individually expressed in the following description.

  As shown in FIGS. 4 and 6, each light source block body 18 includes a plurality of red LEDs, green LEDs, and blue LEDs (referred to collectively as LEDs 12), and these LEDs 12 in the longitudinal direction on the first main surface 19 a. And a horizontally-long rectangular wiring board 19 mounted in a predetermined order. Each light source block 18 has a total of 25 LEDs 12 mounted on each wiring board 19 by combining an appropriate number of red LEDs, green LEDs, and blue LEDs. Therefore, the light source block 11 includes 75 LEDs for each of the light emitting arrays 11A to 11F, for a total of 450 LEDs 12. In the light source block 11, the number of light source block bodies 18 and the number of LEDs 12 mounted on each light source block body 18 are appropriately determined in consideration of the size of the display screen, the light emission capability of each LED 12, and the like.

  Although not shown, the light source block 18 has a wiring pattern for connecting the LEDs 12 in series, lands for connecting the terminals of the LEDs 12, and the like formed on the first main surface 19 a of the wiring board 19. Each wiring board 19 is formed with the same specifications, and is located near one side portion 19b in the width direction of the first main surface 19a and on both sides in the longitudinal direction, and the first connector 20A on the signal input side and the signal The output-side second connector 20B is mounted. The first connector 20A is a signal output connector and has, for example, a 5-pin structure although details are omitted. The second connector 20B is a signal input connector and has, for example, a 6-pin structure although details are omitted.

  As shown in FIG. 3, the light source block 11 includes a light emitting array 11A in the first column, three light source block bodies 18AA to 18AC, and each wiring board 19 with one side portion 19b facing downward in FIG. Arranged in the length direction. In the light source block 11, the light emitting array 11B in the second row has three light source block bodies 18BA to 18BC arranged in the length direction with each wiring board 19 facing one side portion 19b toward the upper light emitting array 11A. Configured. The light source block 11 is configured by arranging the three light source block bodies 18 side by side in the length direction by alternately changing the direction of the wiring board 19 with respect to each of the light emitting arrays 11C to 11F. Is done.

  The light source block 11 has a signal input unit that drives each LED 12 of each column mounted on the wiring board 19 by the second connector 20B of each of the light source block bodies 18AC to 18FC arranged on the right side of each column light emitting array 11A to 11F. Constitute. In the light source block 11, as shown in FIG. 4, one first connector 20A and the other second connector 20B of the light source block bodies 18 arranged adjacent to each other are adjacent to each other. The light source block 11 connects the first connector 20A and the other second connector 20B with a lead wire with a connector (not shown) so that the shortest wiring is performed. The light source block 11 draws out signal output lead wires 21 with connectors from the first connectors 20A of the light source block bodies 18AA to 18FA arranged on the left side for each of the light emitting arrays 11A to 11F. 4, the light guides are led between the light emitting arrays 11 </ b> A to 11 </ b> F and bundled with the clampers 22 provided to the light emitting arrays 11 </ b> A to 11 </ b> F, and pulled out to the second main surface 9 e side of the back panel 9 through the drawer opening 23.

  Although not shown, the light source block 11 has a signal input lead wire with a connector connected to each of the second connectors 20B of the light source block bodies 18AC to 18FC arranged on the right side for each of the light emitting arrays 11A to 11F. Each signal input lead wire is drawn from the second main surface 9e side of the back panel 9 through the drawing opening 23, and bundled with the clamper 22 provided between the light emitting arrays 11A to 11F, and the light source block bodies 18AC to 18FC. Connected. In the light source block 11, the light source block bodies 18 of the light emitting arrays (11A, 11B), (11C, 11D), and (11E, 11F) that make a pair are connected to the first connectors 20A and the second connectors 20A provided on the wiring board 19, respectively. The connectors 20B are arranged to face each other.

  In the light source block 11, as described above, holding the signal input / output lead wires 21 using the space between the light emitting arrays 11 </ b> A to 11 </ b> F and providing a guide structure can improve the space efficiency and simplify the wiring process. Figured. In the light source block 11, the positions of the first connector 20A and the second connector 20B prevent misconfiguration of the wiring boards 19, and simplify the wiring structure and wiring process between the wiring boards 19 or lead wires. Sharing will be achieved. Further, in the light source block 11, the lead wires 21 can be easily routed to the second main surface 9e side of the back panel 9 by such a structure. In the light source block 11, since the lead wire for signal input and the lead wire for signal output are guided by being bundled by the clamper 22, these lead wires cooperate to suppress noise.

  In the light source block body 18, a red LED, a green LED and a blue LED, which are combined in an appropriate number as described above, are arranged on the first main surface 19a of the wiring board 19 in this order on the same axis, Twenty-five LEDs 12 are mounted. As for each LED12, as shown in FIG. 7, the light emitting element 12a is hold | maintained at the resin holder 12b, and the terminal 12c is pulled out from the resin holder 12b.

  In the light source block 11, the LEDs 12 of the light source block body 18 are turned on to generate heat as the display light is emitted. Since the light emitting unit 7 forms the light guide space portion H whose periphery is sealed by combining the light source block 11 on the back side of the optical sheet block 10 as described above, the heat generated from each of the plurality of LEDs 12 is large. There is a possibility that the amount of heat becomes so large that the light guide space H is trapped in a high temperature state. The light emitting unit 7 changes the characteristics of the optical sheet bodies described above of the optical sheet block 10 due to the increase in temperature, causes the lighting state of the LEDs 12 to become unstable, and causes color unevenness in the liquid crystal panel 5. This causes problems such as destabilizing the operation of electronic components and the like.

  In the backlight unit 3, the light emitting unit 7 efficiently radiates the heat generated from each LED 12 by the heat radiating unit 8, thereby preventing the above-described problem. The heat dissipating unit 8 is provided for each of the light emitting arrays 11A to 11F described above and has six heat dissipating plates 24A to 24F (hereinafter collectively referred to as heat dissipating plates 24) that also serve as attachment members for the light source block body 18, and these heat dissipating units. Six heat pipes 25A to 25F (hereinafter collectively referred to as heat pipes 25) combined with the plate 24, and a pair of left and right heat sinks 26A and 26B (hereinafter referred to as heat sinks) to which both ends of the heat pipes 25 are connected. 26), and a cooling fan 27 for promoting the cooling function of the heat sink 26. The heat radiating unit 8 forms an efficient heat conduction path for the heat sink 26 by assembling a heat pipe 25 integrally with each heat radiating plate 24 as will be described in detail later.

  Each of the heat radiating plates 24 is made of an aluminum material having excellent thermal conductivity, good workability, light weight, and low cost, and has a length substantially equal to the length and width of each of the light emitting arrays 11A to 11F described above by extrusion. It is formed in a rectangular plate shape. Since each heat radiating plate 24 also serves as an attachment member of the light source block body 18, it is formed with a predetermined thickness having mechanical rigidity. Note that each heat radiating plate 24 is not limited to an aluminum material, and may be formed of, for example, an aluminum alloy material, a magnesium alloy material, a silver alloy material, or a copper material having good thermal conductivity. If each heat dissipation plate 24 is relatively small, it may be formed by an appropriate processing method such as pressing or cutting.

  As shown in FIG. 6 and FIG. 7A, each wiring board 19 of the light source block 18 abuts the end face in the length direction on each heat radiation plate 24 with the first main surface 24a as an overlapping surface. Combined by state. Each heat radiating plate 24 is formed with a board fitting recess 24b in which the wiring board 19 is fitted to the first main surface 24a over the entire length. Each heat dissipating plate 24 has a board fitting recess 24b substantially the same width as the wiring board 19 and a height substantially equal to the thickness thereof, and the wiring board 19 is arranged in the width direction of the second main surface 19c. Hold both side edges and combine. Each heat dissipating plate 24 fixes the wiring board 19 combined with the board fitting recess 24 b onto the first main surface 24 a by a plurality of mounting screws 28.

  In each of the heat radiating plates 24, the receiving surface portion 24 c in the length direction in which the second main surface 19 c of the wiring substrate 19 is in close contact with each other by leaving the central region in the width direction as a convex portion having a predetermined width in the board fitting recess 24 b. And the meat stealing recesses 24d and 24e are formed on both sides of the receiving surface 24c over the entire length in the length direction. As shown in FIG. 7A, each heat radiating plate 24 is formed with a width corresponding to the LED mounting area 19d on which each LED 12 of the wiring board 19 is mounted, as shown in FIG. 7A. The heat is efficiently transmitted from the LED mounting region 19d that is heated and heated most by the operation, so that heat is radiated. In addition, although each heat sink plate 24 formed the meat stealing recessed parts 24d and 24e in order to maintain weight reduction and dimensional accuracy, you may make it utilize these meat stealing recessed parts 24d and 24e as a heat pipe fitting part. .

  Each heat radiating plate 24 is formed with a heat pipe fitting recess 24g into which the heat pipe 25 is fitted on the second main surface 24f side facing the first main surface 24a. Each heat dissipating plate 24 is integrally formed with a plurality of mounting stud portions 24h and positioning dowels 24i that constitute a mounting portion with the back panel 9 at an appropriate position on the second main surface 24f. The heat pipe fitting recess 24g is a groove having a substantially arch-shaped cross section formed over the entire region in the length direction at a substantially central portion in the width direction facing the receiving surface portion 24c. As will be described later, the heat pipe fitting recess 24g is formed with an opening shape that allows the heat pipe 25 fitted therein to be temporarily held without a holding member or the like. The heat pipe fitting recess 24g has an opening width substantially equal to the outer diameter of the heat pipe 25, and is formed with a slightly small height (depth).

  In the heat dissipating unit 8, the heat pipe fitting recess 24g is formed over the entire length in the length direction on the second main surface 24f side of the heat dissipating plate 24 and one heat pipe 25 is attached. In order to improve the heat dissipation capability, for example, two or more heat pipes 25 may be attached to each heat dissipation plate 24. Since each heat pipe 25 interferes with each other and the heat conduction ability may be lowered by attaching to each heat radiation plate 24 at the same location, one heat pipe 25 is attached to each second main surface 24f. Two or more heat pipe fitting recesses 24g parallel to each other are preferably formed adjacent to each other.

  In the heat radiating unit 8, for example, when two or more heat pipes 25 are attached to the heat radiating plate 24, the heat radiating unit 24 has the same diameter due to the characteristic of the heat pipe 25 that does not change much in the heat conduction ability due to the difference in outer diameter. It is preferable to use it. With this measure, the heat pipe 25 can share parts, prevent assembly errors, and the like.

  In the heat radiating unit 8, one heat pipe 25 is attached to a heat pipe fitting recess 24 g formed in each heat radiating plate 24. In the heat dissipating unit 8, due to the configuration of the transmissive liquid crystal display device 1, for example, it may be necessary to form an attachment part such as a part in the middle of the heat pipe fitting recess 24g, Since it cannot arrange | position, the heat pipe 25 becomes long, and the heat conductive capability of a front-end | tip part may fall. In the heat radiating unit 8, two short heat pipes 25 may be fitted from the left and right sides in the heat pipe fitting recess 24g.

  As described above, the heat radiating unit 8 is formed with the heat pipe fitting recess 24g in each heat radiating plate 24, and the heat pipe 25 is assembled therein. It is arranged at a position closer to the mounting area 19d. The heat dissipating unit 8 uses each heat dissipating plate 24 having a predetermined thickness, and a heat pipe fitting recess 24g having an interval (thickness) between the apex portion and the receiving surface portion 24c of about 1 mm is formed on the heat dissipating plate 24, for example. As a result, the LEDs 12 mounted on the wiring board 19 having a thickness of about 1.7 mm to 1.8 mm and the heat pipes 25 are arranged to face each other at an interval of 2 mm or less, and efficient heat dissipation is performed. It becomes like this.

  In the heat radiating unit 8, each heat radiating plate 24 also serves as a holding member for the heat pipe 25 by attaching the heat pipe 25 in the heat pipe fitting recess 24g. The handling is simplified and the occurrence of bending or breakage is prevented. In the heat radiating unit 8, each heat radiating plate 24 is combined with the light source block body 18 and the heat pipe 25 positioned and close to each other. An efficient heat conduction path is formed between them. In the heat radiating unit 8, simplification of the attaching process of the heat pipe 25 to each heat radiating plate 24 is achieved.

  In the heat dissipating unit 8, each heat dissipating plate 24 is attached to the back panel 9 with the light source block body 18 combined with the board fitting recess 24b and the heat pipe 25 assembled in the heat pipe fitting recess 24g. It is precisely positioned and fixed via the part 24h and the positioning dowel 24i. Each of the heat radiating plates 24 may be fixed on the first main surface 9d of the back panel 9 by using an attachment screw 28 for fixing the wiring board 19.

  Each of the heat radiating plates 24 has a heat pipe fitting recessed portion 24g having an arch-shaped recessed portion that can be formed with high dimensional accuracy by an extrusion process, but it is needless to say that the shape is not limited thereto. . The heat pipe fitting recess 24g may have any shape as long as the heat pipe 25 is fitted and held and adhesion to the outer periphery thereof is maintained. It is also possible to form in a shape.

  By the way, each heat radiating plate 24 presses the heat pipe 25 assembled in the heat pipe fitting recess 24g by the back panel 9 so as to adhere to the inner wall. For example, the dimensional accuracy of each part or the dimensional accuracy of the back panel 9 It is also considered that a gap is partially formed between the heat pipe 25 and the like and the heat conductivity is lowered. Therefore, in each heat radiating plate 24, as shown in FIG. 7B, for example, the heat pipe 25 may be caulked in the heat pipe fitting recess 24j by a caulking structure.

  Each heat dissipating plate 24 is formed so that the heat pipe fitting recess 24j has a depth substantially equal to the outer diameter of the heat pipe 25, and the heat pipe fitting recess 24j has a full length at the opposite opening edge. The caulking convex portions 24k and 24l are integrally formed. The caulking convex portions 24k and 24l may be formed at one opening edge portion of the heat pipe fitting concave portion 24j or may be partially formed. The caulking convex portions 24k and 24l may be provided in a staggered manner, for example, when they are partially formed at the opening edge portions facing each other.

  Each heat radiating plate 24 has the heat pipe fitting recess 24j assembled in the heat pipe fitting recess 24j with respect to the caulking projections 24k and 24l as shown by the chain line in FIG. 7B. Apply the caulking process to bend inward. In each heat radiation plate 24, the heat pipe 25 is pressed against the inner wall of the heat pipe fitting concave portion 24j by the caulking convex portions 24k and 24l and is brought into close contact therewith. Each heat dissipating plate 24 is more reliably integrated with the heat pipe 25, and the adhesion to the back panel 9 is also improved.

  In each of the heat dissipation plates 24, heat pipe fitting recesses 24g and 24j opened in the second main surface 24f are formed and the heat pipe 25 is attached from the second main surface 24f side. It is not limited. In each heat radiating plate 24, a heat pipe fitting hole opened at at least one end in the longitudinal direction may be formed so that the heat pipe 25 is assembled therein. Moreover, in each heat radiating plate 24, you may make it form the heat pipe fitting recessed part opened to the end surface of the width direction.

  The heat pipe 25 is a member generally used for conducting heat from a high-temperature power supply unit or the like to various heat dissipating means in various electronic devices, and is made of a metal pipe such as copper having excellent heat conductivity. It is configured by enclosing a conductive medium such as water that is vaporized at a predetermined temperature in a state where the inside of the material is exhausted, and has a highly efficient heat conduction capability. As described above, the heat pipe 25 is integrally assembled with each heat radiating plate 24, and both ends of each heat pipe 25 are connected to a heat sink 26 described later. In the heat pipe 25, the conduction medium enclosed inside receives heat conduction from the high-temperature side heat radiating plate 24 and vaporizes from liquid to gas. In the heat pipe 25, the vaporized conductive medium flows through the pipe to the connection portion with the low-temperature heat sink 26 and is cooled, thereby releasing condensation heat and liquefying. In the heat pipe 25, the liquefied conductive medium moves to the heat radiating plate 24 side by a capillary phenomenon through a plurality of longitudinal grooves or porous layers formed on the inner wall of the metal pipe, and circulates in the pipe. As a result, it has a highly efficient heat conduction effect.

  The heat pipe 25 is provided in each of the light emitting arrays 11A to 11F and is opposed to the light source block body 18 by being integrally mounted in the pipe fitting recess 24g of the heat radiating plate 24 as described above. The heat pipe 25 is mounted in the pipe fitting recess 24g with a part of the outer peripheral portion protruding from the opening. As the heat pipe 25 is attached to the back panel 9 by attaching the heat radiating plate 24, the protruding portion is pressed into the pipe fitting recess 24g as shown by the arrow in FIG. It will be in close contact. As described above, the heat pipe 25 does not require a holding member with respect to the heat radiating plate 24, and is kept in close contact in the pipe fitting recess 24g. In general, the heat pipe 25 is combined by applying silicon grease or the like to the mounting portion in order to maintain adhesion with the heat radiating member. However, by adopting the above-described structure, such a countermeasure becomes unnecessary.

  The heat pipe 25 is more reliably integrated with the heat radiating plate 24 by adopting the above-described caulking structure shown in FIG. Become.

  In the heat radiating unit 8, the heat pipe 25 having a high efficiency of heat conduction is integrally mounted in the pipe fitting recess 24 g formed in the heat radiating plate 24 having the above-described configuration, so that the heat pipe 25 is a heat source. It becomes the structure extended near right under the arrangement | sequence area | region of each LED12. In the heat radiating unit 8, the wiring board 19 on which each LED 12 is mounted, the heat radiating plate 24 holding the wiring board 19, and the heat pipe 25 are overlapped with each other to form a heat conduction system to the heat sink 26. . In the heat radiating unit 8, space efficiency is achieved by such a configuration, and heat generated from each LED 12 is conducted to the heat sink 26 very efficiently to radiate heat, thereby suppressing the light guide space H from being heated to a high temperature. The backlight unit 3 supplies display light to the liquid crystal panel 5 with a stable operation.

  In the heat radiating unit 8, as shown in FIG. 8, the heat sinks 26 are respectively attached to the second main surface 9 e of the back panel 9 so as to be located on both sides in the length direction. These heat sinks 26 are also used alone or in combination with the heat pipe 25 as a heat radiating member such as a power source in various electronic devices. The heat sink 26 is a member having a large surface area by integrally forming a large number of fins from an aluminum material having excellent thermal conductivity. The heat sink 26 cools the high temperature part by receiving heat conduction from the high temperature part side and radiating heat from the surface of each fin.

  The larger the heat sink 26, the greater the heat dissipation effect. However, the heat sink 26 is preferably small because the thickness of the backlight unit 3 and the entire apparatus is increased and increased in size. The heat sink 26 is a large and heavy component. For example, when directly attached to a wiring board or the like, a heat conducting member interposed between a mounting bracket member or a high-temperature portion that retains insulation from a circuit component or a wiring pattern or the like. Etc., and the structure becomes complicated.

  In the heat radiating unit 8, the large-sized heat sink 26 that requires the above-described correspondence together with a plurality of heat radiating plates 24 and heat pipes 25 is skillfully arranged on the back panel 9, thereby increasing the size of the transmissive liquid crystal display device 1. And the heat generated from the multiple LEDs 12 of the light emitting unit 7 is efficiently radiated. In the heat radiating unit 8, the back panel 9 is not required to have a relief recess formed along the arrangement path of the heat pipe 25 due to the configuration of the heat radiating plate 24 and the heat pipe 25 described above. 9 can be formed in a flat shape as a whole. In the heat dissipating unit 8, the flat portion is formed in the central region of the back panel 9 by attaching the heat sinks 26 to the left and right sides of the second main surface 9e as described above with respect to the flat back panel 9. So that

  By the way, the back panel 9 is formed of, for example, an aluminum material that is relatively light and mechanically rigid and has a horizontally-long rectangular plate shape slightly larger than the outer shape of the liquid crystal panel 5. The back panel 9 itself has thermal conductivity, and thus has a function of radiating heat generated from the light emitting unit 7 and circuit components. As described above, the back panel 9 is formed with the outer peripheral wall portion 9a combined with the front frame member 6 at the outer peripheral portion, and a plurality of mounting portions 9b for attaching the optical stud members 17 and the heat radiating plate 24 are fixed. An attachment hole 23 for drawing out the lead wire 21 or the like is formed. The back panel 9 is assembled by superimposing the heat radiating unit 8, the light emitting unit 7, and the liquid crystal panel 5 on the front surface, and further assembled to the mounting portion of the housing 33.

  The transmissive liquid crystal display panel 1 is provided with a control circuit package for driving the liquid crystal panel 5 and controlling the lighting operation of each LED 12 of the light emitting unit 7, and as shown in FIG. Also used as a mounting panel. The details of the control package are omitted, but the liquid crystal controller 29 that outputs a signal for controlling the operation to the liquid crystal panel 5 and the power control units 30A and 30B that control the power supply units of the liquid crystal panel 5 and the light emitting unit 7 are described. Or LED control units 31A and 31B for controlling the operation of the light emitting unit 7.

  In the transmissive liquid crystal display panel 1, a flat region is formed between the heat sinks 26A and 26B disposed on the left and right sides of the second main surface 9e of the back panel 9 as described above. Each control circuit package 29 to 31 is mounted. In the transmissive liquid crystal display device 1, by mounting the control circuit packages 29 to 31 in a flat region, it is possible to firmly mount the control circuit packages 29 to 31 without causing a lift or the like by a simple process. In the liquid crystal display device 1, since the control circuit packages 29 to 31 are thinner than the large heat sink 26 having a large thickness, the overall thinning is maintained.

  The control circuit packages 29 to 31 described above are mounted on a control board (not shown), and the control board is attached to the back panel 9. The control board is attached to the back panel 9 so as to be positioned between the heat sinks 26 arranged on both sides of the back panel 9 as described later.

  In the transmissive liquid crystal display device 1, the display light is supplied to the liquid crystal panel 5 by using a large number of LEDs 12 provided in the light emitting unit 7 as a light source as described above. In the transmissive liquid crystal display device 1, the heat radiating unit 8 having the above-described configuration is provided so that heat generated from each LED 12 is efficiently conducted to the heat sink 26 by the heat radiating plate 24 and the heat pipe 25 to be radiated. By doing so, a large amount of heat is prevented from being trapped in the light guide space H or the like. In the transmissive liquid crystal display device 1, the characteristics of each optical sheet and the like are maintained, and the entire large screen of the liquid crystal panel 5 is maintained in a substantially uniform temperature distribution so that a uniform image without color unevenness is displayed. And the operations of the control circuit packages 29 to 31 are stabilized.

  9 and 10 show the results of measuring the heat dissipation characteristics of the first heat dissipating knit composed of the heat conducting member combined with the heat pipe and the heat sink, and the second heat dissipating knit composed of the heat conducting member and the heat sink. It is shown. In this measurement method, the temperature at the left and right end portions and the center portion with the passage of time was measured in a state where a 34 W applied DDC heat sink was divided from the center and only the right side was left. In the first heat dissipating knit, as shown in FIG. 9A, the overall temperature gradually increases with time, but the temperature difference of each part is stable within 1 ° C. Further, in the first heat dissipating knit, as shown in FIG. 5B, even at the left end where no heat sink exists, efficient heat conduction is performed to the heat sink by the action of the heat conducting member and the heat pipe. A substantially constant temperature distribution is maintained over the entire area.

  On the other hand, in the second heat radiating unit, as shown in FIG. 10A, the overall temperature gradually increases with time, and the right end portion where the heat sink is provided is restrained from rising due to its heat radiating action. The temperature difference between the right end and the left end gradually increases. In the second heat radiating unit, for example, the temperature distribution after 26 hours reaches a maximum of 7 ° C. at the right end and the left end as shown in FIG. Therefore, in the heat radiating unit, by combining the heat conducting member combined with the heat pipe and the heat sink, efficient heat conduction from the high temperature part to the heat sink is performed and heat radiation is performed. And uniform temperature distribution.

  As described above, the heat dissipating unit 7 is improved in heat dissipating efficiency by combining each heat sink 26 with the cooling fan 27. Each heat sink 26 blows air between the fins by the cooling fan 27, thereby promoting heat dissipation from the surface of each fin. The cooling fan 27 is not limited to the blower type, and may be an exhaust type that sucks air from between the fins of the heat sink 26 and exhausts it to the outside of the housing 33.

  In the heat dissipation unit 7, a pair of cooling fans (27A, 27B) and (27C, 27D) are attached to the heat sinks 26, respectively. The cooling fan 27 is also commonly used as a cooling and heat dissipating device by attaching it to a housing or the like in various electronic devices or the like. Each heat sink 26 is configured so that the fins are closed by, for example, a back cover of the housing, etc., except for the mounting portion of the cooling fan 27 so that the cooling air flow path is held.

  As shown in FIG. 12, the cooling fan 27 includes a square frame fan casing 27a, a motor section 27c disposed in the center of the fan casing 27a via a plurality of arm sections 27b, and the motor section 27c. The fan 27d is rotated. In the cooling fan 27, attachment portions 27e are formed at the four corners of the fan housing 27a, and openings 27f penetrating in the thickness direction are formed between the arm portions 27b. The cooling fan 27 is attached with the opening 27f facing the opening 33a formed in the back cover of the housing 33 as shown in FIG. The cooling fan 27 rotates when the motor unit 27c is powered on, and the fan 27d draws air from one side of the opening 27f and exhausts air from the other side. That is, the cooling fan 27 is a so-called vertical cooling fan.

  The cooling fan 27 is attached to the back surface portion of the heat sink 26 by screwing the attachment portion 27e on the attachment portions 26a and 26a having a large width, and is cooled by sending air between the fins through the opening portion 27f. . As shown in FIG. 11, the cooling fan 27 is mounted at a substantially central portion in the length direction of the heat sink 26 to uniformly cool the heat sink 26 in the vertical direction.

  By the way, in the cooling fan 27, when each side of the fan housing 27a is attached in parallel to the fin direction as shown in FIG. 12B, the cooling fan 27 is opened by the attachment portions 26b and 26b on the heat sink 26 side. A part of the part 27f is closed, the amount of air blown between the fins is reduced, and the cooling efficiency is lowered. Therefore, the cooling fan 27 is fixed in a state where each side of the fan housing 27a is inclined by 90 degrees with respect to the fin direction as shown in FIG. The heat sink 26 is efficiently cooled by performing more air blowing.

  As described above, the heat radiating unit 7 is thinned by mounting the control circuit packages 29 to 31 in a flat region formed between the heat sinks 26. When each cooling fan 27 is attached to the back surface of the heat sink 26, the heat radiating unit 7 protrudes toward the back surface. Therefore, the heat radiating unit 7 is sufficiently thin as compared with the conventional device. The effect of reducing the thickness will be slightly impaired.

  Therefore, in the heat dissipation unit 7, the left and right heat sinks 26 may be configured by an upper heat sink 26A1, a lower heat sink 26A2, and an upper heat sink 26B1 and a lower heat sink 26B2, respectively, as shown in FIG. In the heat dissipating unit 7, the upper heat sinks 26A1, 26B1 and the lower heat sinks 26A2, B2 each hold a space sufficient to dispose the cooling fan 32 at a substantially central position in the height direction so as to abut each other. 9 is attached.

  Two cooling fans 32 are arranged between the upper heat sink 26A1 and the lower heat sink 26A2 on one side, and two units 32C are arranged between the upper heat sink 26B1 and the lower heat sink B2 on the other side. 32D is arranged. These cooling fans 32 have a basic configuration similar to that of the vertical cooling fan 27 described above, but a so-called horizontal cooling fan that has an opening formed on the outer peripheral side surface of the casing 27a and blows air in the outer peripheral direction. Used to be attached directly to the back panel 9. Therefore, in the heat radiating unit 7, the cooling fan 32 is arranged between the divided heat sinks as shown in FIG. The

  In the heat dissipating unit 7, a pair of left and right heat sinks 26 are attached to the back panel 9 as described above. The heat sink 26 is integrally formed with a large number of small fins facing each other in parallel by an aluminum material, and has a characteristic shape when cut vertically. Therefore, in the transmissive liquid crystal display device 1, as shown in FIG. 14, an opening 34 is formed in a part of the housing 33, and the end 26 c is exposed to the outside from the opening 34. 26 is attached to the back panel 9.

  The housing 33 is formed so that the opening 34 has an opening size substantially equal to the cross-sectional shape of the heat sink 26, and the front end of the heat sink 26 is fitted so as to form substantially the same surface as the outer surface. Therefore, in the transmissive liquid crystal display device 1, the tip of the heat sink 26 exposed in the opening 34 forms a part of the exterior body in cooperation with the housing 33, and has a unique design from its unique shape and color. Constitute. In the transmissive liquid crystal display device 1, a part of the heat sink 26 is directly exposed to the outside, so that the cooling efficiency can be improved.

  The embodiment described above shows the transmissive liquid crystal display device 1 for a display panel of a television receiver having a large display screen of 40 inches or more, but the present invention is applied to various liquid crystal display devices having a large screen. Is done.

It is a principal part disassembled perspective view of the transmissive liquid crystal display device shown as embodiment. It is a principal part longitudinal cross-sectional view of a transmissive liquid crystal display device. It is a top view of a thermal radiation unit. It is a principal part perspective view of a light source block. It is a principal part longitudinal cross-sectional view of the optical sheet block provided with the optical stud member. It is a perspective view of the assembly of a light source block body and a heat radiating plate. It is a side view of the assembly of a light source block body and a thermal radiation plate. It is a principal part perspective view from the back side of a transmissive liquid crystal display device. It is a heat dissipation characteristic figure of the heat dissipation unit which has a heat pipe and a heat sink. It is a thermal radiation characteristic figure of the thermal radiation unit which has a heat sink. It is a principal part perspective view from the back side of the transmissive liquid crystal display device which combined the cooling fan with the heat sink. It is a principal part top view which shows the attachment structure of the cooling fan to a heat sink. It is a principal part perspective view from the back side of the transmissive liquid crystal display device provided with the combination structure of another heat sink and a cooling fan. It is a principal part perspective view of the transmissive liquid crystal display device using a heat sink as an exterior material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission type liquid crystal display device, 2 Liquid crystal panel unit, 3 Backlight unit, 4 Whole frame member, 5 Liquid crystal panel, 6 Back frame member, 7 Light emitting unit, 8 Heat radiation unit, 9 Back panel, 10 Optical sheet block, 11 Light source Block, 12 Light emitting diode (LED), 13 Optical functional sheet laminate, 14 Diffuse light guide plate, 15 Diffuse plate, 16 Reflective sheet, 17 Optical stud member, 18 Light source block, 19 Wiring board, 20 Connector, 21 Lead wire , 22 Clamper, 23 Drawer opening, 24 Heat radiation plate, 25 Heat pipe, 26 Heat sink, 27 Cooling fan, 29 Liquid crystal controller, 30 Power supply control unit, 31 LED control unit, 32 Cooling fan, 33 Housing, 34 Opening

Claims (6)

A transmissive LCD panel;
A light source block having a light source for emitting display light and attached to the back panel;
A plurality of functional optical sheets, and an optical functional sheet laminate for guiding the display light to the transmissive liquid crystal panel;
A diffusion light guide plate that is combined with the optical functional sheet laminate and diffuses the incident display light in the layer and supplies the diffused light to the optical functional sheet laminate;
A diffusion plate that is opposed to the diffusion light guide plate with a predetermined facing interval, transmits a part of the display light emitted from the light source block, and reflects a part thereof;
A reflection sheet that is opposed to the diffusion plate with a predetermined interval and reflects the display light emitted from the light source block in the outer circumferential direction and the display light reflected by the diffusion plate toward the diffusion plate; ,
A plurality of optical stud members attached to the back panel and defining a spacing between the diffusion plate and the reflective sheet;
Each of the optical stud members is formed at an axial base portion having an axial length that defines an interval between the back panel and the diffusion light guide plate, and a base end portion of the axial base portion. A fitting portion that is attached to a fitting portion formed on the back panel, and a first receiving plate portion that is formed to project from the outer peripheral portion of the shaft-like base portion with a predetermined distance from the fitting portion to hold the reflective sheet And a second receiving plate portion that protrudes from the first receiving plate portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the diffuser plate at a predetermined opposing interval with respect to the reflecting sheet. And a step portion having a small diameter formed at a height position substantially equal to the thickness of the diffusion plate from the second receiving plate portion is integrally formed of a light guide resin material,
The distance between the diffusion light guide plate, the diffusion plate, and the reflection sheet is maintained by combining the diffusion light guide plate with the end portion of the shaft-like base portion being abutted and combined with the back panel. A liquid crystal display device. Each of the optical stud members has a fitting hole formed in the fitting portion of the shaft-shaped base portion and an upper portion of the stepped portion formed in the attachment portion of the back panel and the diffusion plate. Slots and meat stealing holes are formed which are larger than the respective inner diameters of the joint holes and give converging habits to each of these large diameter parts,
The fitting portion is pushed into the attachment hole of the attachment portion and fixed to the back panel, and the fitting hole of the diffusion plate combined from the front end passes through the large-diameter portion and fits into the step portion. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is combined.   2. The liquid crystal display device according to claim 1, wherein each of the optical stud members is integrally formed of a milky white resin material. A light source block having a light source for emitting display light and attached to the back panel;
A plurality of functional optical sheets, and an optical functional sheet laminate for guiding the display light to a transmissive display panel;
A diffusion light guide plate that is combined with the optical functional sheet laminate and diffuses the incident display light in the layer and supplies the diffused light to the optical functional sheet laminate;
A diffusion plate that is opposed to the diffusion light guide plate with a predetermined facing interval, transmits a part of the display light emitted from the light source block, and reflects a part thereof;
A reflection sheet that is opposed to the diffusion plate with a predetermined facing interval and reflects the display light emitted from the light source block to the periphery and the display light reflected by the diffusion plate toward the diffusion plate;
A plurality of optical stud members attached to the back panel and defining a spacing between the diffusion plate and the reflective sheet;
Each of the optical stud members is formed at an axial base portion having an axial length that defines an interval between the back panel and the diffusion light guide plate, and a base end portion of the axial base portion. A fitting portion that is attached to the attachment portion formed on the back panel, and a first receiving plate portion that is formed to protrude from the fitting portion to the outer peripheral portion of the shaft-like base portion with a predetermined interval to hold the reflective sheet And a second receiving plate portion that protrudes from the first receiving plate portion at a predetermined interval on the outer peripheral portion of the shaft-like base portion and holds the diffuser plate at a predetermined opposing interval with respect to the reflecting sheet. And a step portion having a small diameter formed at a height position substantially equal to the thickness of the diffusion plate from the second receiving plate portion is integrally formed of a light guide resin material,
The facing distance between the diffusing light guide plate, the diffusing plate and the reflecting sheet is maintained by the diffusing light guide plate being brought into contact with the tip of the shaft base while being attached to the back panel. Backlight device characterized by doing. Each of the optical stud members has a fitting hole formed in the fitting portion of the shaft-shaped base portion and an upper portion of the stepped portion formed in the attachment portion of the back panel and the diffusion plate. Slots and meat stealing holes are formed which are larger than the respective inner diameters of the joint holes and give converging habits to each of these large diameter parts,
For the back panel, the fitting portion is pushed into the attachment hole of the attachment portion and fixed, and the fitting hole of the diffusion plate combined from the front end side passes through the large-diameter portion to the step portion. The backlight device according to claim 4, wherein the backlight device is fitted. The light source block includes a plurality of wiring boards arranged to face the back surface of the transmissive display panel, and a plurality of light emitting diodes arranged and mounted on the wiring boards on substantially the same axis line. With
5. The backlight device according to claim 4, wherein each of the wiring boards is mounted on a heat radiating plate fixed to the back panel and provided with heat radiating means.

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