JPH01229283A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the efficiency of lighting by arranging a liquid crystal panel on the plane part side of a frame member and a driving circuit base material at the claw part of the frame member, and opposing a light source to a liquid crystal panel across the plane part of the frame member. CONSTITUTION:The claw part 1c of the frame part 1 is set in front of the liquid crystal display device. Consequently, the liquid crystal panel 2, interconnectors 4a and 4b, and driving circuit board 3 are stacked and arranged between the plane part 1a of the frame part 1 and claw part 1c so that the liquid crystal panel 2 is positioned on the side of the plane part 1a; and they are clamped and held by the plane part 1a and claw part 1c. A light source 7, on the other hand, is provided on the side where the claw part 1c of the plane part 1a of the frame part 1 is not present. Further, a contact part 8 such as silicone rubber packing is interposed between the plane part 1a and light source 7. Consequently, the gap between the liquid crystal panel 2 and light source 7 decreases and the brightness of the liquid crystal panel 2 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device, and more particularly to the structure of a liquid crystal display device including a light source device that irradiates light onto the back surface of a liquid crystal panel.

[Conventional technology]

FIG. 2 is a sectional view showing a liquid crystal display device proposed by the applicant in Japanese Patent Application No. 62-246747.

In the figure, 51 is a frame member, and 52 is a liquid crystal panel. 52a is a top glass constituting the liquid crystal panel;
Reference numeral 2b is a lower glass that constitutes the liquid crystal panel. 53a
and 53b is a drive circuit board on which a driver LSI for driving the liquid crystal is mounted. 54a and 54
b is an interconnector for connecting the segment terminals of the top glass 52a of the liquid crystal panel and the segment terminals of the drive circuit boards 53a and 53b, and the main body is made of insulating rubber such as silicone rubber, and the conductive rubber 5
4c (in the vertical direction in the drawing), and this conductive rubber 5
4c are arranged in the direction perpendicular to the plane of the paper, which is directed by the longitudinal force of the main body. These interconnectors 54a, 54b
is a press-contact type connector, which is inserted between the top glass 52a of the liquid crystal panel 52 and the drive circuit boards 53a and 53b in a compressed state of, for example, about 20%, so that the electrodes formed on both are electrically connected well. The frame member 51 is for holding the interconnectors 54a and 54b in a compressed state.

Further, 55 is a light source device having a fluorescent lamp 55a and a light diffusing plate 55b, and this light source device 55 is connected to the frame member 5.
1 is disposed on the side of the claw-shaped portion 51a of the liquid crystal panel 52, and uniformly irradiates light from the back onto the effective display surface of the liquid crystal panel 52, thereby improving the brightness of the display portion of the liquid crystal panel 52.

[Problem to be solved by the invention]

However, in such a conventional configuration, the light source device 55 is disposed on the claw-shaped portion 51a side of the frame member 51, and in this case, due to the thickness of the drive circuit boards 53a, 53b, interconnectors 54a, 54b, etc. (Especially, the interconnector needs to have a thickness of about 4 to 5 mm, since the electrical connection is good when it is appropriately compressed.) There is a gap (usually about 7 to 8 mm), so the light source device 55
There is a problem in that the efficiency of using the light emitted by the liquid crystal panel 52 decreases, and the brightness of the display section of the liquid crystal panel 52 decreases.

Further, in the above configuration, the light source device 55 is arranged on the claw-shaped portion 51a side of the frame member 51, and it is difficult to bring the light source device 55 and the frame member 51 into close contact.
If there is a gap here, there is a problem in that foreign matter such as dust that has entered through the gap adheres to the liquid crystal panel 52, and the shadow of this appears as uneven brightness of the display dots. Further, in order to prevent the entry of foreign matter, it is necessary to cover the gap with another member, but it covers the entire surface between the frame member 51 having the partially protruding claw-like portion 51a and the light source device 55. This has the problem of being difficult to manufacture and disadvantageous in terms of manufacturing costs.

Therefore, the present invention has been made to solve the problems of the prior art as described above, and its purpose is to:
It is an object of the present invention to provide a liquid crystal display device which can effectively utilize back illumination light, prevent foreign matter from entering, and provide a good display.

[Means for solving problems]

The liquid crystal display device of the present invention includes a liquid crystal panel in which signal electrode terminals are arranged along the sides, and a circuit-side electrode terminal that extends along the sides of the liquid crystal panel and is electrically connected to the signal electrode terminals. A drive circuit board, an interconnector that is interposed between the signal electrode terminal of the liquid crystal panel and the circuit side electrode terminal of the drive circuit board and electrically connects these terminals, and corresponds to the display surface of the liquid crystal panel. a flat part having an opening window of a size of 1, a plurality of side parts extending substantially perpendicularly from the periphery of the flat part, and a plurality of side parts provided at the tips of the side parts and folded inward to face the flat part. a frame member having a claw-like portion and holding the liquid crystal panel, the interconnector, and the drive circuit board under pressure between the flat portion and the claw-like portion folded back from the side portion; In the liquid crystal display device having a light source means for illuminating the panel from the back side, the liquid crystal panel is arranged such that the liquid crystal panel is on the plane side of the frame member and the drive circuit board is on the claw-like part side of the frame member. The panel, the interconnector, and the driving circuit board are arranged, and the light source means is sandwiched between the flat parts of the frame member so that the liquid crystal panel is illuminated by the light source means through the opening window of the frame member. It is characterized by being arranged at a position facing the liquid crystal panel.

[For production]

In the present invention, the liquid crystal panel is placed on the flat side of the frame member, the drive circuit board is placed on the claw-like part side of the frame member, and the light source means is placed at a position facing the liquid crystal panel across the flat side of the frame member. It is placed. Therefore, the distance between the liquid crystal panel and the light source means is not affected by the thickness of the drive circuit board or the interconnector, and can be made close to the extent that it is slightly larger than the thickness of the flat part of the frame member. Lighting efficiency can be improved. Furthermore, since the light source means faces the flat surface of the frame member, the front surface of the light source means and the flat surface can be brought into close contact with each other without using a separate member. It can be brought into close contact with
It is possible to create a structure that prevents foreign matter from entering between the light source means and the liquid crystal panel.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a sectional view showing an embodiment of a liquid crystal display device according to the present invention, FIG. 3 is an exploded perspective view of this embodiment, and FIG. 4 is a view of this embodiment as seen from the direction of arrow A in FIG. 1. 5 is a plan view of the drive circuit board 3 of this embodiment, and FIG. 6 is a plan view of the drive circuit board 3 of the present embodiment.
A side view showing a partial cross section along the X-ray, Figure 7 is Y in Figure 5.
A sectional view taken along the -Y line and FIG. 8 are a plan view showing a group of signal electrode terminals of the drive circuit board 3 of this embodiment.

In the figure, 1 is a frame member, 1a is a frame member 1
1b is a plurality of side portions extending substantially perpendicularly from the periphery of the flat portion 1a, lc is a claw-shaped portion (1 cm1 to 1 cm12) folded inward from the tip of the side portion 1b, 1
d is an opening window formed in the center of the plane portion 1a, and these are mainly shown in FIGS. 1, 3, and 4.

Further, 2 is a liquid crystal panel, 2a is an upper glass that constitutes the liquid crystal panel 2, and 2b is a lower glass that constitutes the liquid crystal panel 2. Two mutually parallel sides (the third side) of the bottom glass 2b
Segment electrodes SEa and SEb as signal electrode terminals are provided on the front side (left side in FIG. 3) along the upper side and lower side in the figure. In addition, the bottom glass 2
A common electrode CB is provided on the back side along one of the sides perpendicular to the above two sides of a.

3 is a drive circuit board, and a pair of segment side boards 3a
, 3b and a common side board 3C. Third
As shown in the figure and FIGS. 5 to 8, the common side board 3c has segment side boards 3a and 3 at both ends thereof.
It is overlapped with one end of b and fixed. In this embodiment, the common side substrate 3C is provided closer to the liquid crystal panel 2 than the segment side substrates 3a and 3b. Note that 3d is a control circuit board, and 3e is a holding member that connects the other ends of the segment side boards 3a and 3b.

Here, 5a and 5b are segment side substrates 3a and 3b.
This is a segment terminal (circuit side electrode terminal). Also, 5
c is a common side terminal of the common side board 3c. Further, as shown in FIG. 8, segment terminal reference marks 6a-1, 6a-2 and 6b-1, 6b-2, which serve as positional references during assembly, are provided on the segment side boards 3a, 3b on the common side. The common terminal reference mark 6cm1,6 is on the board 3c.
cm2 is attached. These segment terminal reference marks 6a-1, 6a-2 and 6b-1, 6b-2 are position references used for aligning the liquid crystal panel 2 and the drive circuit board 3, and the common terminal reference marks 6cm1, 6cm
2 is a positional reference used to align the common side board 3c and one end of the tape connector 10.

Moreover, 4a and 4b are interconnectors.

The interconnectors 4a, 4b are compressed by about 20% and are sandwiched between the segment electrodes SBa, SEb of the lower glass 2b of the liquid crystal panel 2 and the segment terminals 5a, 5b of the drive circuit board 3, and the picture electrodes Connect the terminals electrically. The interconnectors 4a and 4b are each made of a main body made of insulating rubber, with conductive rubber 4C inserted through the main body, and a large number of conductive rubber 4C are arranged in the longitudinal direction of the main body. Connection using this interconnector is easier and more cost effective than connection using a conventionally commonly used heat seal type tape connector (for example, thermocompression bonded using an anisotropic conductive adhesive).

Reference numeral 7 denotes a light source device (backlight) as a light source means for irradiating light onto the effective display surface of the liquid crystal panel 2 from the back side, and this light source device 7 includes a fluorescent lamp 7a and a fluorescent lamp 7a.
It has a diffuser plate 7a that diffuses and mixes the light emitted by the light source, and a light guide 7C that transmits the diffused light. In this embodiment, the light source device 7 is a flat part 1a of the frame member 1.
It is provided on the side that does not have the claw-like portion 1c.

In FIGS. 5 to 7 showing details of the drive circuit board 3, 9a and 9b are connection points for exchanging signals between the common side board 3c and the segment side boards 3a and 3b, and 10 is a common side board. Heat-sealable flexible tape connector 1 for connecting common terminal 60 of substrate 3c and common tiCE of bottom glass 2b of liquid crystal panel 2;
1 and 12 are driver ICs (for example, manufactured by Oki Electric Industry Co., Ltd. =
MSM5299), 13 is a driver IC (for example, manufactured by Oki Electric Industry Co., Ltd.: MSM5298), 14 is a control circuit element, 15 is a reference hole for board assembly, and 16 is a segment side board 3a, 3b and a control circuit board 3d. Pin terminals for electrical connection, 17 are common side board 3C and control circuit board 3d
This is a pin terminal that electrically connects the

In this embodiment, each of the above-mentioned configurations is
Assembled as shown. That is, in this embodiment, the claw-like portion IC side (upper side in the figure) of the frame member 1 is the front surface of the liquid crystal display device. For this reason, frame member 1. The liquid crystal panel 2, the interconnectors 4a and 4b, and the drive circuit board 3 are arranged between the flat part 1a and the claw-shaped part IC so as to be located on the flat part 1a side. is held under pressure between the flat portion 1a and the claw-like portion 1c. At this time, the interconnectors 4a and 4b interposed between the liquid crystal panel 2 and the drive circuit board 3 are compressed by about 20% to electrically connect the electrode terminals well. In addition, the claw-like portion IC extends on the same plane as the side portion 1b before the liquid crystal display device is assembled, but by bending it inward along the boundary with the side portion 1b, it becomes as shown in FIG. It is in a state where it extends toward the inside of the liquid crystal panel 2. moreover,
At this time, the length of the claw-like member IC is set so that it extends to a position inside the position where the interconnectors 4a and 4b are provided, and by doing so, the holding state of the interconnector is stabilized and I'm sure.

On the other hand, the light source device 7 of this embodiment is provided on the side of the flat portion 1a of the frame member 1 that does not have the claw-like portion IC. Then, as shown in FIG. 1, the flat part 1 of the frame member 1
A thin contact member 8 such as a packing made of silicone rubber is interposed between the light source bag W7 and the light source device 7, so that there is no gap between the light source bag W7 and the flat part 1a of the frame member 1. There is. Note that the contact member 8, the light source device 7, and the frame member 1 are bonded using, for example, double-sided adhesive tape.

In this embodiment, each structure is arranged as described above, so the distance between the liquid crystal panel 2 and the light source device 7 is determined by the thickness of the flat part 1a of the frame member 1 (however, in FIG. ) and the thickness of the contact member 8. This value is about 1.3mm, which is 5mm compared to the conventional 7-3mm.
It is possible to make the liquid crystal panel 2 and the light source device 7 extremely close to each other. Therefore, even when using the same light source device, the brightness of the liquid crystal panel 2 is at a level that can be clearly identified by visual inspection (approximately 15 to 20%) compared to conventional ones.
Improvement is recognized.

In addition, since there is no gap between the flat part 1a of the frame member 1 and the front surface of the light source device 7, foreign objects such as dust are prevented from entering the space between the flat part 1a and the light source device 7. This can be completely prevented, and the brightness unevenness caused by foreign matter entering, which has been a problem in the past, can be eliminated.

In the above embodiment, a fluorescent lamp is used as the light source device, but the present invention is not limited to this, and other light sources such as an electroluminescence (EL) light source may be used. The present invention is particularly effective in the case of an EL light source, since the amount of light emitted is lower than that of a fluorescent lamp.

Further, in the above example of real colors, a simple matrix type liquid crystal display device has been described, but the present invention is not limited to this. It can be widely applied to what you have. An example of this application is shown in FIGS. 9 and 10. Here, FIG. 9 is an explanatory diagram showing an example of an active matrix type liquid crystal panel in which thin film transistors 21 are arranged in a matrix, and FIGS. 10(a) and (b) are a plan view and a side view of this liquid crystal panel. It is a diagram. In the figure, the same components as in the above embodiment are designated by the same reference numerals.
The explanation will be omitted. However, in FIG. 9, 22 and 23 are portions corresponding to the electrode terminals of the above embodiment, and are portions connected to the electrodes SEa, SEb, and CE of FIG. 10.

FIG. 11 is a plan view showing another example of the drive circuit board applicable to the present invention. In this example, the common board 3c is provided on the side opposite to the control circuit board 3d, and the holding member 3e in the embodiment shown in FIG. 5 can be omitted.In this way, the present invention can be applied to various circuit boards. It is. It should be noted that the configuration other than this is the same as the embodiment shown in FIG. 5 above, so the same components are given the same reference numerals and the explanation thereof will be omitted.

〔Effect of the invention〕

As explained above, in the present invention, the light source device is provided on the side of the flat surface of the frame member that does not have the claw-like portion, so the distance between the liquid crystal panel and the light source device is determined by the distance between the liquid crystal panel and the light source device. This value is determined by the thickness of the liquid crystal panel, and this value is smaller than that of the conventional structure, allowing the liquid crystal panel and the light source device to be brought very close to each other. For this reason, the brightness of the liquid crystal panel is improved compared to conventional panels, and high-quality display can be achieved.

Further, since the light source is provided on the side of the flat portion of the frame member that does not have the claw-like portion, it is possible to easily eliminate a gap between the flat portion of the frame member and the front surface of the light source device. Therefore, it is possible to completely prevent foreign matter such as dust from entering between the flat surface and the light source device, eliminate uneven brightness due to adhesion of foreign matter, and provide a high-quality display. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a liquid crystal display device according to the present invention, FIG. 2 is a sectional view showing a conventional liquid crystal display device, and FIG. 3 is an exploded perspective view of this embodiment. FIG. 5 is a plan view of the driving circuit board of this embodiment, and FIG. 6 is a partial cross section taken along line X-X in FIG. 5. 7 is a cross-sectional view taken along the Y-Y line in FIG. 5, and FIG.
FIG. 9 is an explanatory diagram of another implementation side using an active matrix type liquid crystal panel. FIGS. 10(a) and (b) are plan views of the liquid crystal panel in FIG. 9. and a side view, and FIG. 11 is a plan view showing another example of a drive circuit board applicable to the present invention. 1...Frame member, 1a...Plane part, 1b...
Side part, IC...claw-shaped part, 2...LCD panel, 2a
...Top glass, 2b...Bottom glass, 3...Drive circuit board, 3a, 3b...Segment board, 3c...
...Common side board, 3d...Control circuit board, 4a
+4 b...Interconnector, 7...Light source device. Patent applicant Oki Electric Industry Co., Ltd. Agent Patent attorney Former 1) Actual

Claims (1)

[Scope of Claims] A drive circuit having a liquid crystal panel in which signal electrode terminals are arranged along the sides, and a circuit-side electrode terminal extending along the sides of the liquid crystal panel and electrically connected to the signal electrode terminals. a substrate; an interconnector interposed between the signal electrode terminal of the liquid crystal panel and the circuit side electrode terminal of the drive circuit board and electrically connecting these terminals; and a large interconnector having a size corresponding to the display surface of the liquid crystal panel. a flat part having an opening window; a plurality of side parts extending substantially perpendicularly from the periphery of the flat part; and a claw-like part provided at the tip of the side part and folded inward to face the flat part. a frame member having a portion and holding the liquid crystal panel, the interconnector, and the drive circuit board under pressure between the flat portion and the claw-shaped portion folded back from the side portion; In a liquid crystal display device having a light source means for illuminating from the back, the liquid crystal panel is on the flat side of the frame member,
The liquid crystal panel, the interconnector, and the drive circuit board are arranged so that the drive circuit board is on the claw-shaped portion side of the frame member, and the liquid crystal panel is illuminated by the light source means through the opening window of the frame member. A liquid crystal display device, characterized in that the light source means is disposed at a position facing the liquid crystal panel across the plane part of the frame member so that the light source means is illuminated through the frame member.