JPH09211447A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device which is of a thin type, is small in size and light in weight, is improved in display quality and is inexpensive by constituting a lower frame disposed below an illumination device of a resin material having a thickness of a specific value or below and ribs. SOLUTION: This liquid crystal display device consists of the illumination device, the lower frame 10 arranged below this device and a liquid crystal panel arranged above the same. The lower frame 10 is composed of the resin material having <=0.3mm thickness and the ribs 12 to 15. For example, a sheet consisting a polycarbonate material sized 0.3mm is vacuum formed, by which the ribs 12 to 15 and light source receiving parts 16 are formed and, therefore, the lower frame 10 is obtd. by a blanking machine. While the similar effect is obtd. even by using a polyester film, the polycarbonate material is preferable as the best resin material. Metallic foil having an electromagnetic shielding effect is stuck to the lower frame 10, by which electromagnetic noises are decreased without sacrificing the small thickness, the small size and the light weightness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present application relates to a liquid crystal display device such as a display device of a liquid crystal television receiver, a display device of a liquid crystal display monitor, a display device of a personal computer, etc. The present invention relates to the liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device comprises a liquid crystal panel which is a display section, an external circuit board for controlling or driving the liquid crystal panel, and an illuminating device.

For example, Japanese Patent Laid-Open No. 3-156422 discloses a liquid crystal display device having a built-in lighting device also called a backlight in order to make the display of the liquid crystal panel bright and clear, and further, as a lighting device, a liquid crystal panel There is disclosed an illuminating device called a side light system which is thinner than a direct illuminating device in which a light source is arranged directly below. Further, a configuration diagram of a liquid crystal display device in which a frame is disposed below the illumination device is shown in FIG. 1 of the above-mentioned publication.

Further, Japanese Patent Laid-Open No. 6-347784 discloses a structure similar to that of Japanese Patent Laid-Open No. 3-156422, and discloses a sidelight type liquid crystal display device in which a lower frame is made of an aluminum thin plate. A conventional technique of a liquid crystal display device will be described below with reference to the above publications and the like.

FIG. 7 is an exploded perspective view of a conventional liquid crystal display device. In FIG. 7, the liquid crystal display device includes an illuminating device 120 disposed on the lower frame 100.
A frame-shaped spacer 30 made of a sponge is provided above 20 for the purpose of preventing dust from entering, and an intermediate frame 40 having a window 48 is provided above the spacer 30. The inner frame 40 is provided with a circuit board receiving portion 41 and four screw receiving portions 44 to 47 for fixing the circuit board to the inner frame, and rubber elastic spacer receiving portions 42 and 43 at two places. There is. Elastic spacers 51 and 52 are disposed above the elastic spacer receiving portion 42 and the elastic spacer receiving portion 43 of the middle frame 40. A liquid crystal panel 60 is disposed on the elastic spacers 51 and 52. The liquid crystal panel 60 has X end portions 61 and 62 and a Y end portion 63. Liquid crystal driving ICs are mounted on the glass at the X end portions 61 and 62 (hereinafter, COG mounting), but they are not shown in FIG. 7 because they are located below the sheet. Further, X end portions 61 and 6 further outside the end portion on which the liquid crystal driving IC is mounted.
2 is a flexible circuit board (hereinafter, FPC) 67, 6
8 is connected by anisotropic conductive adhesion or conductive adhesion and bent to the upper surface side of the liquid crystal panel, and then connected to the second circuit board 84 by soldering, conductive adhesion, anisotropic conductive adhesion, or the like. on the other hand,
At the Y end 63 of the liquid crystal panel 60, a liquid crystal driving IC is
Although it is G mounted, the illustration is omitted in FIG. 7. Further, the FPCs 69 and 70 are connected to the Y end 63, which is further outside the end where the liquid crystal driving IC is mounted, by anisotropic conductive bonding or conductive bonding, and after bending to the upper surface side of the liquid crystal panel, the first circuit is formed. It is connected to the substrate 82 by soldering, conductive bonding, anisotropic conductive bonding or the like. The first circuit board 82 and the second circuit board 84, which have the functions of controlling the liquid crystal driving IC, inputting / outputting data, and generating a driving voltage, have connectors for connecting to a circuit board different from the board. doing. Also the first
A flat cable (hereinafter, FFC) connects between the circuit board 82 and the second circuit board 84. The liquid crystal panel 60, the first circuit board 82, and the second circuit board 84 are housed in the middle frame 40, and then the window 94 having substantially the same dimensions of the display unit 66 of the liquid crystal panel 60 and the liquid crystal display device are provided in the housing. Four screw fixing portions 93 for attachment and the first circuit board 82
An upper frame 90 having a circuit board supporting portion 92 that covers the upper frame 90 is provided, and the lighting device 120, the liquid crystal panel 60, and the like are provided in the middle frame 40.
Lower frame 10 made by punching aluminum through
The liquid crystal display device has a structure in which it is sandwiched between 0 and the upper frame 90.

The illumination device 120 is a light source 2 composed of a fluorescent tube.
Light from the light source 22 obtained by reflecting light from the light source 2 directly or by the light source reflecting member 23 is incident on the light guide member 24. Of the light that has entered the light guide member 24, the light that travels downward from the light guide member 24 is reflected by the reflecting member 28 toward the liquid crystal panel 60 that is arranged above. Light emitted from almost the entire upper surface of the light guide member 24 is diffused by the diffusion plate 25 that diffuses the light. The light diffused by the diffusing plate 25 regulates the directivity of the light traveling toward the liquid crystal panel 60 by the two prism sheets 26 and 27. In addition, the lighting device 120
The light source 2 is provided at the end of the lower frame 100 disposed below the
The light source receiving portion 116 for arranging the fluorescent lamp 2 and the light source reflecting member 23 is molded. Further, the light source receiver 116
A notch 113 is formed in the inner wall of the light source 22. The notch 113 prevents the light emitting characteristics of the light source 22 which is a cathode fluorescent tube from being disturbed by the conductive material made of aluminum.

[0007]

As described above, in the conventional liquid crystal display device, the lower frame is mold-molded with a metal member such as aluminum. However, there were limits to miniaturization and weight reduction. Further, since the light emitting characteristics of the light source 22 which is a cathode fluorescent tube are disturbed by aluminum, the lower frame needs to be processed as the cutout portion 113, and the die for molding the lower frame is complicated and the cutout material is formed. Occurred and material loss occurred. In view of the above problems, an object of the present application is to obtain a liquid crystal display device which is thin, small, lightweight, has improved display quality, and is inexpensive.

[0008]

The gist of the present application for solving the above-mentioned problems is to provide a light guide member which is a member arranged at least below a liquid crystal panel and which guides light of a light source in a surface direction of the liquid crystal panel and the light guide member. An illumination device including a light source disposed on the side of the member and a light source reflection member disposed so as to cover the light source except a surface facing the light guide member, and disposed below the illumination device. A liquid crystal display device comprising a lower frame and a liquid crystal panel disposed above the lighting device is characterized in that the lower frame is made of a resin material having a thickness of 0.3 mm or less and ribs. Further, the ribs are arranged on four sides of the lower frame.

The resin material forming the lower frame is polycarbonate. The resin material forming the lower frame is a polyester film.

In addition, the present invention is characterized in that a white pigment is added to the lower frame so that the lower frame has a function as a reflecting member for reflecting the light traveling downward of the light guide member to the liquid crystal panel side. Further, the lower frame is characterized in that metal vapor deposition having at least one of the function of the reflecting member and the function of the shield is formed.
Further, the metal vapor deposition disposed on the lower frame is nickel, silver, or aluminum. The lower frame is provided with a metal foil having at least one of the function of a reflection member and the function of a shield, and the lower frame is also provided. The metal foil is nickel or silver or aluminum.

[0011]

1 to 6 are views showing an embodiment of the present invention, FIG. 1 is a perspective view of a lower frame which is the first embodiment, and FIG. 2 is a view of FIG. FIG. 4 is a sectional view of the lower frame taken along the line AA, FIG. 3 is an exploded perspective view of the liquid crystal display device in the embodiment, FIG. 4 is a perspective view of the lower frame showing the second embodiment, and FIG. FIG. 7 is a perspective view of a lower frame showing a third embodiment, and FIG. 6 shows the lower frame B in FIG.
It is -B sectional drawing. Examples of the present application will be described below.

As shown in FIG.
The ribs 12, 13, 14, 15 and the light source receiving portion 16 are formed by vacuum forming a thin plate made of a 3 mm polycarbonate material, and then the lower frame 10 of FIG. 1 is obtained by a punching machine. The ribs 14 and 15 of the lower frame 10 are shown in FIG.
The cross-sectional shape is as shown in FIG.
A bowl-like shape having a W1 dimension of 2 mm and a D1 dimension of 1.5 with respect to 1 mm, or a shape similar to a bowl, can serve as a lower frame member of a liquid crystal display device. Further, even if a polyester film is used as the resin material forming the lower frame 10, the same effect as that of polycarbonate is obtained, but the resin material is changed to white so that the lower frame 10 has the function of the reflecting member 28 described in the related art. When a white or milky white pigment is added, a polyester film may be used, but the best resin material is a polycarbonate material. Further, in order to reduce the electromagnetic noise from the liquid crystal panel 60 in the lower frame 10, the metal foil 19 having an electromagnetic shield function is formed into a size corresponding to the liquid crystal panel 60 as shown in FIGS. Electromagnetic noise can be reduced without sacrificing thinness, small size, and weight reduction by sticking to the lower frame 10 using an adhesive made of a system or flame-retardant resin material. Although nickel, silver, aluminum, or copper is used as the metal foil 19, aluminum of several tens of μm is used in this embodiment, and aluminum is preferable in terms of price and performance. By disposing the metal foil on the light guide member 24 side, it is possible to obtain the function of reflecting the light propagating inside the light guide member 24 and traveling downward of the light guide member 24. Further, as shown in FIG. 4, a metal vapor deposition film obtained by metal vapor deposition 18 of nickel, aluminum, copper, iron, or silver on a sheet of resin material such as polycarbonate is vacuum-formed to form ribs 12, 1.
After molding 3, 14, 15 and the light source receiving portion 16, the lower frame 10 of FIG. 4 is obtained by a punching machine. At this time, in order to eliminate the influence of metal vapor deposition on the operating characteristics of the fluorescent tube, partial vapor deposition excluding a part or the whole of the lower portion of the fluorescent tube may be performed. Electromagnetic noise is reduced by using such a metal vapor deposition film, and the metal vapor deposition surface is disposed on the light guide member 24 side, so that light propagating inside the light guide member 24 and traveling downward of the light guide member 24 can be generated. The function of reflecting can be obtained. Since the lower frame 10 can be easily provided with a function as a reflecting member for reflecting the light traveling downward of the light guide member 24, only by adding a white pigment to the polycarbonate as the base material of the lower frame 10. The number of parts of the liquid crystal display device can be reduced. A method of giving the lower frame 10 a function as a reflecting member can also be obtained by depositing metal or depositing a metal foil on the lower frame 10 described as the embodiment of the present application. If it is not necessary for the lower frame to have a function of reflecting light that travels downward in the light guide member 24, the surface of the lower frame 10 on which metal vapor deposition or metal foil is attached is the light guide member 2
The surface of the lower frame 10 on the side opposite to 4 may be used.

A liquid crystal display device of the present embodiment constructed by using the lower frame 10 constructed as described above will be described with reference to FIG. In FIG. 3, the liquid crystal display device includes an illumination device 20 disposed on the lower frame 10, and a frame-shaped spacer 30 made of sponge disposed above the illumination device 20 for the purpose of preventing dust from entering. The window 4 above the spacer 30.
A middle frame 40 having 8 is arranged. The inner frame 40 is provided with a circuit board receiving portion 41 and four screw receiving portions 44 to 47 for fixing the circuit board to the inner frame, and rubber elastic spacer receiving portions 42 and 43 at two places. There is. Elastic spacers 51 and 52 are disposed above the elastic spacer receiving portion 42 and the elastic spacer receiving portion 43 of the middle frame 40. The elastic spacer 51,
A liquid crystal panel 60 is disposed on the 52. LCD panel 6
0 has X end portions 61 and 62 and a Y end portion 63. Liquid crystal driving ICs are COG-mounted on the X end portions 61 and 62, but they are not shown in FIG. 3 because they are located below the sheet. Further, FPCs 67 and 68 are connected to the X ends 61 and 62 further outside the end where the liquid crystal driving IC is mounted by anisotropic conductive bonding or conductive bonding, and after bending to the upper surface side of the liquid crystal panel, the second It is connected to the circuit board 84 by soldering or the like. On the other hand, a liquid crystal driving IC is COG-mounted on the Y end portion 63 of the liquid crystal panel 60, but is not shown in FIG. Further, FPCs 69 and 70 are connected to the Y end portion 63, which is further outside the end portion on which the liquid crystal driving IC is mounted, by anisotropic conductive bonding or conductive bonding, and after bending to the upper surface side of the liquid crystal panel, the first circuit is formed. It is connected to the substrate 82 by soldering, conductive bonding, anisotropic conductive bonding or the like. The first circuit board 82 and the second circuit board 84, which have the functions of controlling the liquid crystal driving IC, inputting / outputting data, and generating a driving voltage, have connectors for connecting to a circuit board different from the board. I'm doing it. Further, the first circuit board 82 and the second circuit board 84 are connected by FFC. The liquid crystal panel 60, the first circuit board 82, and the second circuit board 84 are housed in the middle frame 40, and then the window 94 having substantially the same size of the display unit 66 of the liquid crystal panel 60 and the liquid crystal display device are provided in the housing. 4 for mounting
An upper frame 90 formed of a material such as aluminum, stainless steel, or iron having a circuit board supporting portion 92 for covering the first circuit board 82 and a screwing portion 93 at a certain position is provided, and further, the lighting device 20, the liquid crystal panel 60, and the like. The middle frame 4
The liquid crystal display device has a structure in which a polycarbonate sheet having a thickness of 0.3 mm is sandwiched between a lower frame 10 and an upper frame 90, which are vacuum-formed, with a thickness of 0 therebetween.

The illumination device 20 includes a light source 22 made of a fluorescent tube.
The light from the light source is reflected directly or the light from the light source 22 is reflected by the light source reflection member 23, and the light is incident on the light guide member 24. Of the light incident on the light guide member 24, the light guide member 24
Light directed downwards is reflected inside the light guide member 24 toward the liquid crystal panel 60 disposed above the light guide member 24 because the lower frame 10 is molded in white as a reflection color. Light emitted from substantially the entire upper surface of the light guide member 24 is diffused by the diffuser plate 25 that diffuses the light.
The light diffused in 2 is regulated by the two prism sheets 26 and 27 to directivity of the light directed to the liquid crystal panel 60. The lower frame 10 arranged below the lighting device 120
The light source receiving portion 16 formed at the end of is provided with a fluorescent tube which is the light source 22 and a light source reflecting member 23. However, even if the notch 113 of the prior art is not formed, the characteristic of the fluorescent tube is It never falls.

In the above-described embodiment of the present invention, the liquid crystal panel 6 is used.
COG with a drive IC mounted on a transparent substrate
Although described using the technique, the present application is not limited to driving I on a transparent substrate.
It can be applied without mounting C, and can also be applied to TAB technology in which electronic parts such as ICs are mounted on a flexible circuit board. Further, the present application can be applied regardless of the type of the liquid crystal panel. For example, the present application can be applied to a passive type in which pixels in the liquid crystal panel are used or an active type using MIM or TFT, and the same effect as the embodiment of the present application can be obtained.

[0016]

Since the lower frame in the present application has a bowl shape or a shape similar to a bowl shape, the function as a lower frame member of a liquid crystal display device can be obtained, and the lower frame can be made thin, small, lightweight and inexpensive. A liquid crystal display device having an effect can be obtained.
In addition, in order to reduce electromagnetic noise from the liquid crystal panel in the lower frame, a metal foil with an electromagnetic shield function is molded to a size equivalent to that of the liquid crystal panel, and it is attached using an adhesive made of acrylic or flame-retardant resin material. The electromagnetic shielding effect can be obtained without sacrificing thinness, small size, and light weight. Also, when a metal deposition film obtained by applying metal deposition to a sheet of resin material such as polycarbonate is molded to form the lower frame, the metal deposition under the fluorescent tube is partially covered so as not to affect the operating characteristics of the fluorescent tube. By avoiding this, the characteristics of the fluorescent tube as the liquid crystal display device can be improved, and the effects of thinning, small size, light weight, and cost reduction can be obtained. By simply adding a white pigment to the resin material that is the base material of the lower frame, the lower frame can easily be made to have the function of a reflecting member that reflects the light traveling downward of the light guide member to the liquid crystal panel side. Therefore, the number of parts of the liquid crystal display device can be reduced. The effect that the function as the reflecting member is obtained is an effect that can be obtained also in the lower frame of the present application in which a metal foil or metal vapor deposition is applied. With the above effects, there is an effect that a liquid crystal display device which is thin, small, lightweight, has improved display quality, and is inexpensive can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a lower frame according to a first embodiment of the present application.

FIG. 2 is a sectional view taken along line AA of the lower frame in FIG. 1, which is the first embodiment of the present application.

FIG. 3 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present application.

FIG. 4 is a perspective view of a lower frame showing a second embodiment of the present application.

FIG. 5 is a perspective view of a lower frame showing a third embodiment of the present application.

FIG. 6 is a BB cross-sectional view of the lower frame in FIG. 5, which is the third embodiment of the present application.

FIG. 7 is an exploded perspective view showing a conventional technique of a liquid crystal display device.

[Explanation of symbols]

 10 Lower Frame 12, 13, 14, 15 Rib 18 Metal Vapor Deposition 19 Metal Foil 20 Lighting Device 22 Light Source 23 Light Source Reflecting Member 24 Light Guide Member 60 Liquid Crystal Panel

Claims (9)

[Claims] 1. A light guide member, which is a member disposed at least below a liquid crystal panel to guide light of a light source in a surface direction of the liquid crystal panel, a light source disposed on a side of the light guide member, and the light guide member. From a lighting device including a light source reflection member arranged so as to cover the light source except the facing surface, a lower frame arranged below the lighting device, and a liquid crystal panel arranged above the lighting device. In the liquid crystal display device, the lower frame is made of a resin material having a thickness of 0.3 mm or less and ribs. 2. A liquid crystal display device, wherein the ribs are arranged on four sides of the lower frame. 3. The liquid crystal display device according to claim 1, wherein the resin material forming the lower frame is polycarbonate. 4. The liquid crystal display device according to claim 1, wherein the resin material forming the lower frame is a polyester film. 5. The liquid crystal display device according to claim 1, wherein the lower frame is vapor-deposited with metal. 6. The liquid crystal display device according to claim 5, wherein the metal vapor deposition disposed on the lower frame is nickel, silver or aluminum. 7. The liquid crystal display device according to claim 1, wherein a metal foil is provided on the lower frame. 8. The liquid crystal display device according to claim 7, wherein the metal foil disposed on the lower frame is nickel, silver, or aluminum. 9. A liquid crystal display device characterized in that a white pigment is added to the lower frame, and the lower frame has a function as a reflecting member for reflecting the light traveling downward of the light guide member to the liquid crystal panel side. .