JP2007149501A - Backlight unit and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the assembling and disassembling of a backlight unit while reducing the number of components. <P>SOLUTION: This backlight unit 1 is provided with: a light guide plate 15; a lamp unit 16 for supplying light to the light guide plate; and a chassis 19 for housing and unitizing the light guide plate 15 and the lamp unit 16. The light guide plate 15 and the lamp unit 16 are housed in the chassis 19 by being slidingly inserted into the chassis 19. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a backlight unit and a liquid crystal display device including the backlight unit.

  In recent years, a liquid crystal display (Liquid Crystal Display), which is one of the display devices, takes advantage of its thinness and low power consumption. Widely used in

  As such a liquid crystal display device, for example, a transmissive liquid crystal display device excellent in visibility is known (see, for example, Patent Documents 1 to 3). The transmissive liquid crystal display device includes a backlight unit that is a surface light source device provided on the back side of the liquid crystal display panel, and performs display by modulating light of the backlight unit by the liquid crystal display panel. It has become.

  Patent Document 1 discloses that a backlight unit is fitted into a frame-shaped casing and a liquid crystal display panel is slid and inserted. In Patent Document 2, a lamp unit and a light guide plate, which are light source units, an optical sheet, and a liquid crystal display panel are sequentially stacked and stored in a substantially dish-shaped auxiliary chassis. It is shown to be inserted into the casing of a liquid crystal display device. Further, Patent Document 3 describes that a light source integrated with a reflecting plate is slid and assembled to a casing in which a liquid crystal display panel, a light guide plate, and the like are incorporated.

However, the above Patent Documents 1 to 3 do not disclose anything about how the backlight unit itself is assembled into a unit. The backlight unit usually comprises a chassis for unitizing an optical sheet, a light guide plate, a lamp unit, etc., with a substantially dish-shaped first chassis member and a substantially frame-shaped second chassis member, As in Patent Document 2, the second chassis member is mounted on the opening side of the first chassis member in a state in which the light guide plate, the lamp unit, and the optical sheet are stacked and housed in the first chassis member. ing.
JP 11-258599 A JP 2003-50395 A JP-A-6-51293

  However, in the structure of the conventional backlight unit described above, the chassis for unitizing the light guide plate, the lamp unit, and the like is composed of two chassis members, which increases the number of parts and increases the cost. There's a problem.

  Furthermore, in order to attach and fix the second chassis member to the first chassis member, screws, locking claws, and the like are required. If screws are used, the number of parts will increase further. Further, when fastening fixing with a screw or locking fixing with a locking claw or the like is applied, for example, when it is desired to repair and replace only the lamp unit, there is a problem that it becomes difficult to remove the lamp unit.

  The present invention has been made in view of such various points, and an object of the present invention is to facilitate the assembly and disassembly of the backlight unit while reducing the number of parts.

  In order to achieve the above object, in the present invention, the light guide plate and the light source unit are slid into the chassis and stored.

  Specifically, a backlight unit according to the present invention includes a light guide plate, a light source unit for supplying light to the light guide plate, and a chassis for housing the light guide plate and the light source unit as a unit. The backlight unit is provided, and the light guide plate and the light source unit are housed in the chassis by being slid into the chassis.

  The direction in which the light guide plate is slid into the chassis preferably intersects the direction in which the light source unit is slid into the chassis.

  It is preferable that the light source unit is slid into the chassis housing the light guide plate.

  The light source part preferably has a stopper part that supports the light guide plate housed in the chassis.

  The liquid crystal display device according to the present invention includes the backlight unit, a liquid crystal display panel stacked on the backlight unit, and a casing that houses the liquid crystal display panel and the backlight unit.

-Action-
Next, the operation of the present invention will be described.

  The light guide plate and the light source unit are unitized by being housed in a chassis. That is, the light guide plate and the light source unit are each slid into the chassis and thereby housed in the chassis. Therefore, in the backlight unit according to the present invention, the chassis is constituted by one member instead of a plurality of members, so that the number of parts is reduced and the cost is reduced. That is, a screw or a locking claw for assembling and fixing a plurality of chassis is not required.

  Furthermore, since the light guide plate and the light source unit are slid into the chassis and housed, the backlight unit can be assembled relatively easily. On the other hand, for example, when the light source unit is repaired and replaced, the light source unit is slid from the chassis and detached. That is, the backlight unit is disassembled relatively easily because it does not require the effort to remove the screws or release the engaged state.

  If the slide movement direction of the light guide plate with respect to the chassis intersects the slide movement direction of the light source unit, one of the light guide plate and the light source unit housed in the chassis is then slid into the chassis. The other of the housed light guide plate and light source unit can be supported and fixed. That is, for example, first, in a state where the light guide plate is slid into the chassis and stored, the light source unit is slid into the chassis and stored. Accordingly, the rear end portion of the light guide plate in the slide movement direction can be supported by the slide movement direction side portion of the light source unit. That is, special fixing means such as screws are not required, and the number of parts can be further reduced. In this case, if the light source part is provided with a stopper part, the light guide plate can be supported by the stopper part.

  If the liquid crystal display device includes the backlight unit, the number of components is reduced as the entire liquid crystal display device.

  According to the present invention, since the light guide plate and the light source unit are slid and inserted into the chassis, the number of components can be reduced to reduce the cost, and the backlight unit can be reduced. Assembly and disassembly can be performed easily.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
1 to 6 show Embodiment 1 of the present invention. 4 is a perspective view showing the backlight unit 1 and the liquid crystal display panel 10, and FIG. 5 is a perspective view showing the backlight unit 1 on which the liquid crystal display panel 10 is laminated and the casing 11. As shown in FIG. FIG. 6 is a perspective view schematically showing the appearance of the liquid crystal display device 2.

  As shown in FIG. 5, the liquid crystal display device 2 includes a backlight unit 1 which is a planar light source device, a liquid crystal display panel 10 stacked on the front side (that is, the observer side) of the backlight unit 1, and a liquid crystal A display panel 10 and a casing 11 that houses the backlight unit 1 are provided. The liquid crystal display panel 10 and the backlight unit 1 are integrated and protected by a casing 11.

  The casing 11 is formed in a rectangular frame shape (frame shape) by using, for example, an aluminum alloy. An opening 13 for exposing the liquid crystal display panel 10 to the outside is formed in the casing 11.

  The liquid crystal display panel 10 has a general structure. That is, although not shown, a TFT substrate in which a thin film transistor (hereinafter abbreviated as TFT) is formed for each of a plurality of pixels on a glass substrate, a transparent electrode serving as a common electrode on the glass substrate, It has a counter substrate on which a color filter or the like is formed, and a liquid crystal layer provided between the TFT substrate and the counter substrate. The liquid crystal display panel 10 is provided with a driver for driving the TFTs.

  The backlight unit 1 emits uniform planar light from a surface facing the liquid crystal display panel 10 and makes the emitted light enter the liquid crystal display panel 10. Thus, the liquid crystal layer is driven for each pixel arranged in a matrix so as to transmit and modulate predetermined light to perform a desired display.

  Here, the backlight unit 1 will be described in detail.

  As shown in FIG. 1 that is an exploded perspective view, the backlight unit 1 includes a light guide plate 15, a lamp unit 16 that is a light source unit for supplying light to the light guide plate 15, an optical sheet 17, and a reflection sheet 18. And a chassis 19 that houses the light guide plate 15, the lamp unit 16, the optical sheet 17, and the reflection sheet 18. Thus, the chassis 19 unitizes the light guide plate 15, the lamp unit 16, the optical sheet 17, and the reflection sheet 18.

  The light guide plate 15 is made of a resin such as polycarbonate or polymethyl methacrylate, and is formed as a plate-like member. One side surface of the light guide plate 15 is an incident surface 15a on which light from the lamp unit 16 is incident. On the other hand, the front surface (that is, the surface on the observer side) of the light guide plate 15 is an emission surface from which light inside the light guide plate 15 is emitted. The light guide plate 15 repeats the diffusion and reflection of the light incident from the incident surface 15a inside, and then emits uniform light from the emitting surface to the emitting surface.

  The optical sheet 17 is laminated on the front surface side of the light guide plate 15 and includes, for example, a plurality of diffusion sheets that diffuse light and a prism sheet interposed between the diffusion sheets. The diffusion sheet preferably has a diffusion particle coating on both sides of a PET (polyethylene terephthalate) sheet. The prism sheet is formed using, for example, polyethylene terephthalate as a base material, and a prism structure having a substantially triangular cross section is formed on the surface thereof by an ultraviolet curable resin. Thus, the brightness of the display light is improved by bringing the traveling direction of the light emitted from the emission surface of the light guide plate 15 closer to the normal direction of the display surface in the liquid crystal display panel 10. In addition, the structure of the optical sheet 17 is not limited to this, It can change suitably according to the specification requested | required.

  The reflection sheet 18 is laminated on the back side of the light guide plate 15 (that is, the surface opposite to the observer side), reflects the light emitted from the light guide plate 15 to the back side, and again returns to the front side. The light guide plate 15 is made incident on the light guide plate 15. The reflection sheet 18 is formed using, for example, polyethylene terephthalate as a base material, and is provided with, for example, a white diffusion layer or a metal vapor deposition layer.

  As shown in FIG. 1, the lamp unit 16 includes a fluorescent tube 21 that is a light source, a frame 22 that holds the fluorescent tube 21, and rubber holders 23 provided at both ends of the fluorescent tube 21. The frame 22 is formed in a substantially U-shaped cross section extending along the fluorescent tube 21. That is, the frame 22 has a groove 22a having a concave cross section, and the fluorescent tube 21 is disposed inside the groove 22a. Although not shown, electrodes are provided at both ends of the fluorescent tube 21, and a harness for supplying power is connected to the electrodes by solder or the like. The rubber holder 23 is provided at both ends of the fluorescent tube 21 so as to cover and protect the electrode, the solder connection portion, and the like.

  The frame 22 is formed of, for example, a metal such as stainless steel, and functions as a reflection unit that reflects the light from the fluorescent tube 21 toward the light guide plate 15 (that is, the opening side of the groove 22a in the frame 22). The rubber holder 23 serves as a stopper portion that supports the light guide plate 15 accommodated in the chassis 19.

  As shown in FIG. 1, the chassis 19 is configured to accommodate the light guide plate 15 and the lamp unit 16 by slidingly inserting the light guide plate 15 and the lamp unit 16.

  That is, as shown in FIGS. 1 and 3, the chassis 19 is formed in a box shape having a plurality of openings, and is a portion that extends along the side surface of the chassis 19 and accommodates the lamp unit 16. And a light guide plate that is adjacent to the lamp storage unit 25 and stores the light guide plate 15, the optical sheet 17, and the reflection sheet 18 (hereinafter sometimes collectively referred to as the light guide plate 15 or the like). The storage part 26 is comprised. The bottom portion of the chassis 19 is formed in a step shape at the boundary between the lamp housing portion 25 and the light guide plate housing portion 26.

  On the front side of the chassis 19, a first opening 31 for emitting planar light is formed so as to extend over a part of the light guide plate storage part 26 and the lamp storage part 25. Since the first opening 31 is formed slightly smaller than the front surface of the chassis 19, the inner wall surface of the chassis 19 around the first opening 31 supports the front surface of the light guide plate 15 and the like. Yes.

  On the back side of the chassis 19, a second opening 32 is formed mainly for weight reduction in the light guide plate housing portion 26. The inner wall surface of the light guide plate housing 26 around the second opening 32 supports the back surface of the light guide plate 15 and the like. In addition, the inner wall surfaces on the three side surfaces of the light guide plate housing portion 26 support the three side surfaces of the light guide plate 15 and the like. The other one side surface of the light guide plate 15 and the like is supported by the lamp unit 16 as described later.

  A third opening 33 for slidingly inserting the light guide plate 15 and the like is formed in the side portion of the lamp housing portion 25. The width of the third opening 33 is slightly larger than the width of the light guide plate 15 or the like. On the other hand, the height of the third opening 33 is slightly larger than the height of the light guide plate 15 and the like. As shown in FIGS. 2 and 3, the inner wall surface of the chassis 19 around the third opening 33 supports the side surface of the lamp unit 16 (the side surface of the frame 22). That is, as shown in FIG. 3, the side portion of the lamp housing portion 25 is formed in an L-shaped cross section by forming the third opening 33.

  Further, a fourth opening 34 for slidingly inserting the lamp unit 16 is formed on one side surface of the chassis 19 adjacent to the third opening 33. The width and height of the fourth opening 34 are slightly larger than the width and height of the lamp unit 16, respectively.

  When the backlight unit 1 is assembled and manufactured, first, the light guide plate 15 and the like are slid and inserted into the chassis 19 through the third opening 33 in the direction indicated by the arrow A in FIG. As a result, the light guide plate 15 and the like are stored in the light guide plate storage portion 26 of the chassis 19. The light guide plate 15 is housed inside the light guide plate housing portion 26 while being guided and slid along the side portion of the light guide plate housing portion 26 formed in a groove shape.

  Thereafter, the lamp unit 16 is slid and inserted into the chassis 19 through the fourth opening 34 in the direction intersecting the direction A and indicated by the arrow B in FIG. The direction A and the direction B are preferably orthogonal. The lamp unit 16 is guided along the inner wall surface of the lamp housing part 25 formed in a groove shape, and is housed inside the lamp housing part 25 by sliding. As a result, the light guide plate 15 and the like are supported by the rubber holder 23 which is a stopper portion of the lamp unit 16 and positioned inside the light guide plate storage portion 26. Further, the third opening 33 and the fourth opening 34 of the chassis 19 are respectively closed by the lamp unit 16. Thus, the lamp unit 16 is slid into the chassis 19 in which the light guide plate 15 is housed.

  As shown in FIG. 4, the manufactured backlight unit 1 is provided with the liquid crystal display panel 10 overlaid on the optical sheet 17 in the first opening 31 of the chassis 19. After that, as shown in FIG. 5, the casing 11 is mounted from the front side of the chassis 19, whereby the liquid crystal display device 2 is manufactured as shown in FIG.

-Effect of Embodiment 1-
Therefore, according to the first embodiment, the light guide plate 15 and the lamp unit 16 and the like are slid into the chassis 19 and stored, so that the number of components of the constituent members can be reduced and the cost can be reduced. In addition, the backlight unit 1 can be easily assembled and disassembled.

  That is, in this embodiment, since the chassis 19 of the backlight unit 1 is composed of a single member instead of a plurality of members, there is no need for screws or locking claws for assembling and fixing the plurality of chassis. Thus, the number of parts can be reduced and the cost can be reduced.

  Furthermore, since the light guide plate 15 and the lamp unit 16 can be stored in the chassis 19 by simple slide insertion, the backlight unit 1 can be assembled relatively easily. On the other hand, for example, when the lamp unit 16 is to be repaired and replaced, the lamp unit 16 can be slid and removed from the fourth opening 34 in the chassis 19. That is, the backlight unit 1 of this embodiment can be disassembled relatively easily because it does not require the effort of removing screws or the like and releasing the engagement state between a plurality of chassis.

  Furthermore, since the slide direction A of the light guide plate 15 with respect to the chassis 19 intersects the slide direction B of the lamp unit 16, the light guide plate 15 housed in the chassis 19 is then slid into the chassis 19. The lamp unit 16 can be supported and fixed. Therefore, special fixing means such as screws for fixing the light guide plate 15 to the chassis 19 is not required, and the number of parts can be further reduced. Thus, when the liquid crystal display device 2 includes the backlight unit 1, the number of components can be reduced as the entire liquid crystal display device.

<< Embodiment 2 of the Invention >>
7 and 8 show Embodiment 2 of the present invention. In the following embodiments, the same portions as those in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, the configuration other than the casing 11 is the same as that of the first embodiment. That is, the casing 11 is made of, for example, an aluminum alloy and is formed in a rectangular frame shape. The casing 11 has an opening 13 on the front side and an opening 12 on the back side. Further, an opening 14 is formed on the side surface of the casing 11. As a result, as shown in FIG. 7, the side portion of the casing 11 is formed in a groove shape, and the backlight unit 1 and the liquid crystal display panel 10 are slid into the casing 11 along the groove. It has become. As a result, the liquid crystal display device 2 is manufactured as shown in FIG.

  Therefore, the effect similar to the said Embodiment 1 can be acquired also by this embodiment. In addition, the backlight unit 1 and the liquid crystal display panel 10 can be held by the groove shape on the side of the casing 11.

<< Other Embodiments >>
In each of the above-described embodiments, the light guide plate 15 is first stored in the chassis 19 and then the lamp unit 16 is stored. The light guide plate 15 is positioned and fixed by the lamp unit 16, but the present invention has this structure. It is not limited. That is, the lamp unit 16 may be slid into the chassis 19 and stored first, and then the light guide plate 15 may be inserted by sliding. In other words, according to the present invention, whichever comes first in the order in which the light guide plate 15 and the lamp unit 16 are stored in the chassis 19. Even in this case, it is preferable that the sliding direction A of the light guide plate 15 intersects the sliding direction B of the lamp unit 16. As a result, the lamp unit 16 can be positioned and fixed by the light guide plate 15.

  Further, the light guide plate 15 and the lamp unit 16 may be slid in the same direction. For example, in the first embodiment, the fourth opening 34 may be omitted, and both the light guide plate 15 and the lamp unit 16 may be slid and inserted from the third opening 33.

  Further, the lamp unit 16 is not limited to the fluorescent tube 21, and other light sources such as LEDs can be applied.

  As described above, the present invention is useful for the backlight unit and the liquid crystal display device including the backlight unit, and is particularly suitable for the case where the assembly and disassembly of the backlight unit are facilitated while reducing the number of components. Yes.

FIG. 3 is an exploded perspective view illustrating a configuration of a backlight unit according to the first embodiment. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is a perspective view which shows the external appearance of a backlight unit and a liquid crystal display panel. 1 is an exploded perspective view illustrating a configuration of a liquid crystal display device of Embodiment 1. FIG. 1 is a perspective view illustrating an appearance of a liquid crystal display device according to Embodiment 1. FIG. 6 is an exploded perspective view showing a configuration of a liquid crystal display device of Embodiment 2. FIG. 1 is a perspective view illustrating an appearance of a liquid crystal display device according to Embodiment 1. FIG.

Explanation of symbols

A Direction in which light guide plate is slid and inserted B B Direction in which lamp unit is slid and inserted 1 Backlight unit 2 Liquid crystal display device 10 Liquid crystal display panel 11 Casing 15 Light guide plate 16 Lamp unit (light source unit)
17 Optical sheet 18 Reflecting sheet 19 Chassis 23 Rubber holder (stopper part)

Claims (5)

A backlight unit comprising a light guide plate, a light source unit for supplying light to the light guide plate, and a chassis for storing the light guide plate and the light source unit as a unit,
The backlight unit, wherein the light guide plate and the light source unit are accommodated in the chassis by being slid into the chassis. In claim 1,
The backlight unit is characterized in that a direction in which the light guide plate is slid into the chassis intersects with a direction in which the light source unit is slid into the chassis. In claim 2,
The backlight unit, wherein the light source unit is slid into the chassis that houses the light guide plate. In claim 3,
The backlight unit, wherein the light source unit includes a stopper unit that supports the light guide plate housed in the chassis. The backlight unit of claim 1;
A liquid crystal display panel laminated on the backlight unit;
A liquid crystal display device comprising: a casing for housing the liquid crystal display panel and the backlight unit.

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