JP3322592B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

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 in which a liquid crystal cell having illumination means is accommodated in a frame.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display device, as shown in JP-A-5-173708, a circuit board for driving a liquid crystal is arranged around a liquid crystal cell, and an illuminating means is provided on the back of the liquid crystal cell. They are arranged, supported by a resin frame, and housed in a frame to form a so-called liquid crystal module.

[0003]

However, in such a liquid crystal display device, a linear light source such as a cold cathode tube is used as a light source of the illuminating means. The light source is covered with a reflective sheet, but since the reflective sheet is conductive like aluminum foil or a metal-deposited sheet, a linear light source or This is disadvantageous because a capacitive leak path is formed between the power supply line and the power supply line, resulting in insufficient light quantity or overload of the power supply unit. If the reflecting sheet does not have a curved surface so as to efficiently guide the light to the edge of the light guide plate, the amount of light becomes insufficient or brightness unevenness occurs on the display surface, and the reflecting sheet is wound around a linear light source. If the linear light source is brought into contact with the tube of the linear light source, lighting failure will occur. Therefore, the reflection sheet must be provided separately from the linear light source and have a predetermined curved surface, which is difficult. Was.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and includes a liquid crystal cell, a light guide plate disposed on the back surface of the liquid crystal cell, and an end face of the light guide plate. Illuminating means including a linear light source and a sheet surrounding the linear light source, a frame accommodating the liquid crystal cell and the illuminating means, and a back lid fixed to the frame and closing a bottom surface of the illuminating means. The sheet comprises a reflection sheet surrounding the linear light source in a non-contact manner and a flexible insulating sheet completely covering the reflection sheet, and the sheet is aligned with a position mark on the liquid crystal cell side. It is fixed to the light guide plate, and is detachably fixed to the light guide plate on the back cover side, and a deformation portion for positioning is provided at a longitudinal edge of the insulating sheet. It is a liquid crystal display device.

Further, the present invention provides a liquid crystal cell, a light guide plate disposed on the back surface of the liquid crystal cell, a linear light source disposed on an end face of the light guide plate, and a reflection sheet surrounding the linear light source in a non-contact manner. A method of manufacturing a liquid crystal display device, comprising: a lighting unit including a liquid crystal cell, a frame housing the liquid crystal cell and the lighting unit, and a back cover fixed to the frame and closing a bottom surface of the lighting unit. Is attached to the light guide plate on the liquid crystal cell side, and a flexible insulating sheet that completely covers the reflective sheet is overlaid on the reflective sheet, and one edge of the insulating sheet is positioned on the liquid crystal cell side. The light guide plate is fixed to the light guide plate in accordance with the mark, the position is adjusted on the back cover side using a deformed portion provided on the insulating sheet, and the other edge of the insulating sheet is attached to the light guide plate on the back cover side. Liquid crystal display device that is detachably fixed It is a method of manufacture.

[0006]

FIG. 1 is a sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a rear view of the liquid crystal display device with its back cover removed.
FIG. 6 is a positional relationship diagram b and c between the reflection sheet and the insulating sheet, and an enlarged view d of a main part indicated by D in the rear view a. In these figures, reference numeral 1 denotes a liquid crystal cell in which, for example, a nematic liquid crystal is sandwiched between glass substrates and a polarizing plate is adhered to the substrate surface. Such a liquid crystal cell 1 has a substrate 2 around its periphery.
The substrate 2 has a driving element 21 for the liquid crystal cell 1.
A drive board 22 having (integrated circuit elements) and a circuit board 23 for supplying power and signals to the drive elements 21, such as a multilayer printed circuit board, are supported by a buffer if necessary. Although not shown, it may be folded and stored.

Reference numeral 3 denotes a resin frame disposed around the rear surface of the liquid crystal cell 1, which is made of, for example, polycarbonate, ABS, or a mixture of these resins. This resin frame 3
The frame has a substantially rectangular shape, and the central through-hole substantially corresponds to the effective display surface of the liquid crystal cell 1.
At least a part of the housing. In the resin frame 3, the thickness of the thickest portion is, for example, about 5 mm, the crosspiece (frame) portion is 3 mm, the thinnest portion is 1 mm, and the like. , Which is thinner than before.

Reference numeral 4 denotes a frame made of a metal molded body, in which the liquid crystal cell 1 and the illuminating means 5 are housed. The frame body 4 also has a through hole corresponding to the effective display surface at the center substantially in correspondence with the center through hole of the resin frame 3, and has a box shape, and has vertical portions 42 in four directions around the periphery.
Has a claw 43 at a part thereof and is engaged with the resin frame 3. The frame body 4 is preferably used as a pair with a back cover 41 fixed to the resin frame 3 and closing the bottom surface.

Reference numeral 5 denotes an illuminating means including a light guide plate 51 disposed on the back surface of the liquid crystal cell 1 and a linear light source 52 disposed on the opposite end face of the light guide plate 51. The light guide plate 51 is a transparent flat plate made of acrylic resin or the like, and has a reflection sheet on the back surface as necessary, and a light diffusion means such as a diffusion sheet or a lens plate on the front surface. In addition, the linear light sources 52 disposed so as to face each one side surface include a cold cathode tube or the like, and are covered with a sheet for efficiently guiding light to the light guide plate. The reflection sheet 53 has one end (the upper side in FIG. 1: the liquid crystal cell 1 side) abutting on the light guide plate 52 and surrounding the linear light source 52 in a non-contact manner, and a flexible insulating material covering the reflection sheet 53. The sheet 54 is overlapped. Reflective sheet 53
In FIG. 2, the edge is illustrated by a broken line. The insulating sheet 54 covers the reflecting sheet 53, and one end (the lower side in FIG. 1: the long side portion A exposed and shown in FIG. 2A) has a light guide plate 5.
1 and is fixed so as to be releasable with a mending tape 55 or the like, and a deformed portion 56 for positioning is provided at the longitudinal end B.

In order to efficiently transmit the light to the light guide plate, a highly reflective sheet such as an aluminum foil or a metal-deposited sheet is used as the reflection sheet 53. For example, a sheet having a thickness of 30 to 60 μm such as polyethylene or polyethylene terephthalate on which silver has been deposited is used. First of all, since these reflection surfaces are conductive, a frame or a frame back cover, such as a metal frame, is used. Contact with components or the like is disadvantageous because a capacitive leak path is formed between the linear light source and the power supply line, resulting in insufficient light quantity or overload of the power supply unit. Therefore, in the present invention, the reflection sheet 53 is covered with the insulation sheet 54, as shown in FIG. 2B. The reflection sheet 53 completely covers the reflection sheet 53 as shown in FIG. 2C. It must be assembled so that it does not protrude. Such an assembly is shown in FIGS.
The light guide plate 51 in the vicinity where the edge of the sheet is located as shown in FIG.
For example, using the notch of the light guide plate or the corner of the reflection plate attached to the light guide plate, a position mark is attached, and the sheet is fixed on the display side and fixed on the back surface. ,
If the two sheets are overlapped so that the reflection sheet is not visible when aligning with the position mark, the configuration can be made very easily. Further, the reflection sheet 53 is replaced with a flexible insulating sheet 54.
When they are stored in the frame body 4, they can slide easily with the vertical portion 42 of the frame body 4 and can be stored without damaging the reflection sheet 53, so that the assembling workability is good.

If the reflecting sheet 53 is not formed with a curved surface so as to efficiently guide light to the edge of the light guide plate 51, the amount of light becomes insufficient or brightness unevenness occurs on the display surface. It has been found that when the sheet is wrapped around or in contact with the tube of the line light source, the line light source causes lighting failure, but if the sheet has a so-called waist, a beautiful curved surface can be formed only by aligning the edges. Therefore, in the present invention, as the insulating sheet 54, for example, a sheet that is stiffer is laminated by itself or a reflective sheet, such as a polyester sheet having a thickness of 30 to 70 μm. This is because, when the display side is fixed and the insulating sheet 54 is brought into contact with the light guide plate 51 and is fixed with the mending tape 55 or the like, as shown in FIG. If it is set to 32, a curved surface can be formed very efficiently.

[0012]

According to the above construction, in order to use the linear light source of the illuminating means and efficiently transmit the light to the light guide plate, the reflection sheet is not brought into contact with a metal part or the like, and The curved surfaces are formed to guide light efficiently, their assembling operability is good, and the linear light source can be easily replaced by fixing it with mending tape on the back surface. By observing the above, it was possible to reassemble the reflection sheet with extremely high workability, and it was possible to provide a display device which was thin but robust and had high display quality.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a rear view a of the liquid crystal display device according to the embodiment of the present invention with the back cover removed, and a positional relationship diagram b, c between a reflection sheet and an insulating sheet.
FIG. 4 is an enlarged view d of a main part indicated by D in the rear view a.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal cell 2 Substrate 3 Resin frame 4 Frame 5 Lighting means 51 Light guide plate 52 Linear light source 53 Reflection sheet 54 Insulation sheet

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-184828 (JP, A) JP-A-8-95041 (JP, A) JP-A-7-270788 (JP, A) JP-A-4- 269702 (JP, A) JP-A-6-160849 (JP, A) JP-A-3-119913 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/13357 G02F 1 / 1335 G02F 1/1333 G09F 9/00-9/46

Claims (2)

(57) [Claims] 1. A liquid crystal cell, a light guide plate disposed on the back surface of the liquid crystal cell, a linear light source disposed on an end face of the light guide plate, and
A lighting unit including a sheet surrounding the linear light source ; a frame housing the liquid crystal cell and the lighting unit; and a frame fixed to the frame.
A back cover for closing the bottom surface of the lighting means, and the sheet is a reflection sheet surrounding the linear light source in a non-contact manner.
Or a flexible insulating sheet that completely covers the reflective sheet
And the sheet is positioned on the liquid crystal cell side.
Fixed to the light guide plate in accordance with the mark, and
On the back cover side, it is detachably fixed to the light guide plate.
In order to align the longitudinal edges of the insulating sheet,
Liquid crystal display characterized by having a deformed portion for
apparatus. 2. A liquid crystal cell and a liquid crystal cell disposed on the back of the liquid crystal cell.
Light guide plate, a linear light source disposed on an end face of the light guide plate,
Illumination means including a reflection sheet surrounding a linear light source in a non-contact manner
A frame housing the liquid crystal cell and the lighting means;
A back cover fixed to the frame and closing the bottom surface of the lighting means
A method of manufacturing a liquid crystal display device, wherein an edge of the reflection sheet is guided on the liquid crystal cell side.
Flexible insulation that is attached to the light plate and completely covers the reflection sheet on the reflection sheet
Superposed sheets, one edge of the insulating sheet in the liquid crystal cell side
It is fixed to the light guide plate in accordance with the position mark, and is positioned on the back cover side using a deformed portion provided on the insulating sheet.
Align the other edge of the insulating sheet on the back cover side
A liquid crystal, which is fixed to the light guide plate so as to be peelable.
A method for manufacturing a display device.