JPH11237630A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin liquid crystal display device which has large display capacity and having taken measures against noise. SOLUTION: This device has a resin frame 3 arranged at the peripheral part of the back of a liquid crystal cell 1, a lighting means which is arranged on the back of the liquid crystal cell 1, and a frame body 4 which contains the liquid crystal cell 1, resin frame 3, and lighting means 5. A driving element for the liquid crystal cell 1 is folded back at the end edge of a light guide plate 51 on the side where no light source is present and arranged on the back of the lighting means 5 by a flexible substrate connected to the liquid crystal cell 1. The lighting means 5 consists of the light guide plate 52 arranged on the flank of the light guide plate 5, a light source 52 arranged on the flank of the light guide plate 5, a light source reflecting material 53 which covers the light source 52, and a reflecting sheet 54 which is arranged on the back of the light guide plate 52. The driving element is arranged on the liquid crystal cell 1 side of a printed board 3 having a wide electrode pattern, a conductive reflecting material is provided at the place of the lighting mean 5 corresponding to at least driving element, and the reflecting sheet 54 is insulated from the light source reflecting material 53 and connected to an earth potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a driving element and illumination means together with a liquid crystal cell.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display device, a circuit board for driving a liquid crystal is connected to a peripheral portion of a liquid crystal cell, and an illuminating means is provided on a rear surface of the liquid crystal cell, as shown in Japanese Patent Application Laid-Open No. 5-173708. They were arranged and stored in a frame to form a so-called liquid crystal module. The drive element is made of a metal frame and covered with a metal back plate or the like to take measures against noise.

[0003]

However, in such a liquid crystal display device, a liquid crystal cell uses a clock having a higher frequency as the display capacity increases.
Further, if the entire display device is to be made thin, it is difficult to cover the entire display device with a metal plate, which causes inconveniences such as emission of noise and malfunction due to external noise.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and includes a liquid crystal cell, an illuminating means arranged on the back of the liquid crystal cell, and an illuminating means arranged on the back of the illuminating means. In a liquid crystal display device having a driving element for a liquid crystal cell, the driving element is arranged on the liquid crystal cell side of a printed circuit board having a wide electrode pattern, and at least a portion corresponding to the driving element of the lighting means is electrically conductive. It is provided with a reflective material, preferably the illumination means, a light guide plate disposed on the back of the liquid crystal cell, a light source disposed on the side of the light guide plate, a light source reflector covering the light source, a light guide plate It is composed of a reflection sheet disposed on the back, and the reflection sheet is insulated from the light source reflector and connected to the ground potential. More preferably, the driving element is driven by a flexible substrate connected to the liquid crystal cell. Light board light Is disposed folded back in without side edge, the liquid crystal cell and the illumination means are those housed in the frame body is connected to the ground potential.

[0005]

FIG. 1 is a sectional view of an essential part of a liquid crystal display device according to an embodiment of the present invention, which shows a single light source type.
Is a light source side, and b is a light source facing side. In the case of the two-light source type, the light sources are usually arranged on opposite side surfaces. In FIG. 1, reference numeral 1 denotes a liquid crystal cell, for example, a liquid crystal cell in which a nematic liquid crystal is sandwiched between glass substrates and a polarizing plate is adhered to the surface of the substrate. 2 is a liquid crystal cell 1 of a hard or flexible printed circuit board 3 having a wide electrode pattern 30 connected to a peripheral portion of the liquid crystal cell 1 by a flexible substrate 31.
It is a driving element arranged on the side, and may include a controller and a timing processing circuit in addition to the liquid crystal driver. The driving element 2 includes a flexible substrate 3 connected to the liquid crystal cell 1.
1, the light guide plate 51 is folded back at the edge on the side where the light source 52 is not provided, so that the mutual influence of the lighting high frequency of the light source 52 can be reduced.

[0006] Reference numeral 4 denotes a resin frame disposed around the rear surface of the liquid crystal cell 1.
1 is provided. The resin frame 4 is shaped like a frame having a substantially rectangular shape. The central through-hole substantially corresponds to the effective display surface of the liquid crystal cell 1, and accommodates the light guide plate 51 of the illuminating means 5. The resin frame 4 is made of, for example, polycarbonate or A
It is made of BS or a mixture of these resins, and the thickness of the thickest part is as thin as, for example, about 5 mm.

[0007] Illumination means 5 arranged on the back of liquid crystal cell 1
Is a light guide plate 51 arranged corresponding to the back surface of the liquid crystal cell 1.
And a linear light source 52 composed of a cold cathode tube or the like arranged to face one side surface of the light guide plate 51. The light guide plate 5 is a transparent flat plate made of an acrylic resin. In the illustrated example, a wedge-shaped flat plate is shown. The light source 52 includes a light source 52
Light source reflector 53, preferably made of a glossy resin sheet or the like, which covers the light guide plate 5 in a non-contact manner so that light can be efficiently transmitted to the light guide plate 5.
1 is formed. Then, the light guide plate 51
A reflection sheet 54 is disposed on the back surface of the light guide plate 51, and light diffusion means such as a lens plate is provided on the surface of the light guide plate 51 as necessary. When the reflection sheet 54 is insulative, a conductive reflection material 55 is provided at least at a position corresponding to the drive element 2 of the lighting means 5. The reflection sheet may be integrated, or when the reflection sheet 54 is conductive, the reflection sheet may be configured to also serve as a reflection material. In addition, the lead wire 56 of the light source 52 is led out through the gap of the resin frame 4.

Reference numeral 6 denotes a frame made of a metal molded body for accommodating the liquid crystal cell 1, which has a through hole in the center substantially corresponding to the effective display surface, has a box shape, and has vertical portions 62 in four directions around the periphery. , Hanging part 62
Has nails in part. The frame 6 houses the liquid crystal cell 1, the resin frame 4, and the illumination means 5.

In such a configuration, the driving element 2 includes the wide electrode pattern 30 of the printed circuit board 3 and the illumination means 5.
Since it is electrically sandwiched by the conductive reflecting material 55, the noise is shielded, and the reflecting sheet 54 is insulated from the light source reflecting material 53 and connected to the ground potential, and the electrode pattern 30 is also a pattern of the ground potential. , Which means that it is electromagnetically shielded. When the frame 6 is connected to the ground potential and kept at the same potential, the noise resistance is further improved.
In this case, when the reflection sheet 54 and the light source reflector 53 are electrically connected to each other, the output of the light source 52 is reduced. Should not be placed.

[0010]

According to the above construction, a display device resistant to noise can be provided even if the display device is a thin large-capacity display screen or the entire display device is not covered with a thick metal box.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention.
a indicates the light source side, and b indicates the light source facing side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal cell 2 Drive element 3 Printed circuit board 30 (Wide) electrode pattern 4 Resin frame 5 Illumination means 51 Light guide plate 52 Light source 53 Light source reflector 54 Reflection sheet (Possible also as reflector) 55 Reflector 6 Frame

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yuichi Tsubaki 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A liquid crystal display device comprising: a liquid crystal cell; illuminating means disposed on a back surface of the liquid crystal cell; and a driving element of the liquid crystal cell disposed on a back surface of the illuminating means. A liquid crystal display device which is disposed on a liquid crystal cell side of a printed circuit board having a wide electrode pattern, and a conductive reflecting material is provided at least at a position corresponding to a driving element of the illuminating means. 2. The light source includes: a light guide plate disposed on a back surface of a liquid crystal cell; a light source disposed on a side surface of the light guide plate; a light source reflector covering the light source; 2. A liquid crystal display device according to claim 1, wherein said reflection sheet is insulated from said light source reflector and connected to a ground potential. 3. The driving element is disposed so as to be folded at a light-source-free end of the light guide plate by a flexible substrate connected to the liquid crystal cell, and the liquid crystal cell and the lighting unit are connected to a ground potential. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is housed in a frame.