JPH08220554A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: To make a liquid crystal panel thinner while its display area is being protected in the transmission type liquid crystal display device. CONSTITUTION: A transparent protection member 6 made of resin in an acrylic system is dropped in a recessed section which is formed in such a way as not to be in contact with a transparent insulating layer by removing an opaque substrate by etching out of a display area in the liquid crystal driving circuit substrate comprising a liquid crystal driving element layer built in the opaque substrate via the transparent insulating layer, the side wall of the recessed section is fixedly bonded with the side wall of the protection member 6 by adhesives 7, and simultaneously a polarizing plate 20 is disposed at the surface side faced to the transparent insulating layer of the transparent protection member 6 so as to be a liquid crystal panel.

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 used for projection televisions, video viewfinders and the like.

[0002]

2. Description of the Related Art In recent years, as a liquid crystal display device, an active matrix driving method in which driving of liquid crystal is controlled by a switching element for each pixel has been widely used. An example thereof is shown in FIG. FIG. 5 is a schematic sectional view of a liquid crystal panel of a conventional liquid crystal display device. In the figure, 1 is a liquid crystal driving element layer, 2 is a transparent insulating layer, 3 is a liquid crystal driving circuit board, 4 is a sealing material, 5 is liquid crystal, 6 is a transparent protective member, 7 is an adhesive agent, and 8
Is a concave portion, 9 is a counter substrate, 10 is a color filter layer, 1
1 is a transparent electrode, 12 is an orientation control film, 14 is an opaque substrate,
Reference numeral 15 is a transparent substrate, 20 and 20 'are polarizing plates, and 21 is an outer frame.

As shown in FIG. 5, a panel of a conventional liquid crystal display device has a liquid crystal driving circuit substrate 3 having a liquid crystal driving element layer 1 on an opaque substrate 14 with a transparent insulating layer 2 interposed therebetween, and a transparent substrate 15 on the liquid crystal driving circuit substrate 3. The color filter layer 10, the transparent electrode 11,
The liquid crystal 5 is sandwiched between the counter substrate 9 having the orientation control film 12 and the opaque substrate 14 corresponding to the display area is cut out to the transparent insulating layer 2 by etching to obtain a light transmitting property. The film left after the above-mentioned hollowing, that is, the membrane composed of the liquid crystal driving element layer 1 and the transparent insulating layer 2 had a very thin thickness of several μm, and had a structure weak against external pressure such as atmospheric pressure and contact. In order to prevent such external pressure and further invasion of dust and the like, conventionally, an adhesive margin is provided in the non-recessed portion of the opaque substrate 14 other than the display region, and the transparent protective member 6 is attached with the adhesive 7.

[0004]

However, in the above-mentioned conventional example, since the liquid crystal panel is constructed by stacking the three substrates of the counter substrate 2, the liquid crystal driving circuit substrate 3, and the transparent protection member 6, the entire liquid crystal panel is formed. This is not desirable for a liquid crystal display device in which the thickness becomes large and the thinness of the display device is an advantage. Further, a means of thinning the transparent protective member 6 has been considered, but this is not preferable because the workability such as handling of the protective member 6 and handling at the time of sticking a polarizing plate is deteriorated.

In view of the above problems, it is an object of the present invention to provide a liquid crystal display device having a thin panel while protecting the membrane.

[0006]

According to the present invention, there is provided a drive circuit board having a liquid crystal drive element layer via a transparent insulating layer on an opaque substrate having a hollowed-out display area as described above. In a transmissive liquid crystal display device having a liquid crystal panel in which a liquid crystal is sandwiched between a counter substrate having a transparent electrode, a transparent protective member is prevented from coming into contact with the transparent insulating layer in the recess formed by the hollowing. The invention is characterized by being dropped and fixed.

In the present invention, since the thickness of the transparent protective member can be increased by the depth of the recess, the protective member and the polarizing plate can be easily handled. Moreover, since the transparent protective member is fixed without contacting the transparent insulating layer, the external force applied to the protective member does not directly affect the membrane and protects the membrane, while at the same time preventing dust and the like from entering.

[0008]

【Example】

[Embodiment 1] FIG. 1 is a schematic sectional view of a liquid crystal panel according to an embodiment of the present invention. 5 that are the same as those in FIG. 5 indicate the same parts as in FIG. 5 described above.

As shown in FIG. 1, the liquid crystal panel of this embodiment has a counter substrate 9 having a transparent electrode 11 formed on a transparent substrate 15, a liquid crystal driving circuit substrate 3, and a liquid crystal driving circuit substrate 3 formed on the circuit substrate 3. The transparent insulating layer 2, the liquid crystal driving element layer 1, the sealing material 4, the liquid crystal 5, and the transparent protective member 6 are formed. The counter substrate 9 is further provided with a color filter 11 and an alignment control film 12 for aligning the liquid crystal 5 in a fixed direction.

A transparent pixel electrode and a thin film transistor (TFT) for applying a signal to the pixel electrode are formed in a membrane area corresponding to the bottom of a recess 8 formed by hollowing out the liquid crystal driving circuit board 3. Around the membrane, horizontal and vertical shift registers for driving the TFT are provided. The method disclosed in Japanese Patent Laid-Open No. 3-194115 was used to manufacture the liquid crystal driving circuit board 3.

The manufacturing process of the liquid crystal panel of this embodiment will be briefly described with reference to FIG.

First, the liquid crystal driving element layer 1 is formed on the opaque substrate 14 via the transparent insulating layer 2 and the sealing material 4 is printed, and then the color filter layer 10, the transparent electrode 11 and the transparent electrode 15 are further formed on the transparent substrate 15. It was bonded to the counter substrate 9 formed with the alignment control film 12 made of polyimide, and the liquid crystal 5 was injected and sealed (FIG. 2A).

Next, in order to obtain a transmissive liquid crystal panel,
The opaque substrate 14 was etched from the back surface side at a temperature of 90 ° C. for 10 hours using a 22% tetramethylammonium hydroxide (TMAH) solution using the etching resistant mask material 13, and was cut out leaving a membrane in the display area (FIG. 2). (B)).

The transparent protective member 6 was dropped into the recess 8 of the liquid crystal driving circuit board 3 formed by the above etching. In this embodiment, the transparent protective member 6 is a glass plate having no birefringence, but when the polarizing plate is arranged between the membrane and the transparent protective member 6, the material of the transparent protective member 6 is an acrylic birefringent material. A resin molded body may be used.

When the transparent protection member 6 was dropped, a glass plate thinner than the depth of the recess 8 was used so as not to contact the membrane. In the case of this embodiment, the depth of the recess 8 is 0.62.
Since it is mm, a glass plate having a thickness of 0.5 mm was used. Similarly, regarding the size of the transparent protective member 6, the recess 8 is formed so that the transparent protective member 6 does not come into contact with the membrane and the transparent protective member 6 does not protrude to the back surface side of the liquid crystal driving circuit board 3.
While the opening of 10 is 10 mm × 13 mm, 10.
It cut | disconnected so that it might become 1 mm x 13.1 mm.

As shown in FIG. 2C, the transparent protective member 6
Was fixed to the tip of the press with a vacuum chuck 16 so as not to enter the recess 8 obliquely, and after being inserted into the recess 8, the vacuum was released and dropped.

Finally, a silicone adhesive 7 was applied to the side walls of the transparent protective member 6 and the recess 8 with a dispenser and cured to complete the liquid crystal panel of this embodiment (FIG. 2 (d)).

In this embodiment, the outer dimensions of the transparent protective member 6 are limited to the depth of the recess 8 and the size of the opening,
By dropping into the concave portion 8, it was possible to prevent intrusion of external pressure, dust, etc. such as contact of atmospheric pressure to the membrane without increasing the thickness of the liquid crystal panel.

[Embodiment 2] FIG. 3 is a sectional view showing a second embodiment of the present invention, in which the transparent protective member 6 is made of an acrylic resin molding.

Since the molded body may disturb polarized light due to random birefringence generated during molding, the polarizing plate is arranged between the membrane and the transparent protective member 6.

In this embodiment, the liquid crystal panel can be made thin as in the case of Embodiment 1, and since the transparent protective member 6 is a resin molded product, the processing accuracy is good and chipping or chipping like a glass plate does not occur. There is no need to worry. Furthermore, it is cheaper than a glass plate.

[Embodiment 3] FIG. 4 is a sectional view showing a third embodiment of the present invention in which a transparent protective member 6 is integrated with an outer frame for protecting a liquid crystal panel.

In the case of this embodiment, the material of the transparent protective member 6 may be a resin molded body as in the case of the second embodiment, and a portion corresponding to the transparent protective member is a transparent acrylic resin molded body, It may be a two-color molded body in which the frame portion is a resin molded body having a light shielding effect such as black. Furthermore, it is also possible to use a composite body in which the transparent protective member portion is glass and the outer frame portion is a resin molded body.

In this embodiment, since the transparent protective member 6 is integrated with the outer frame, the work of mounting the outer frame is unnecessary. As a result, a thin liquid crystal panel similar to that of the first and second embodiments is configured, and further, the manufacturing process and parts can be reduced, and the manufacturing cost can be reduced.

[0025]

As described above, according to the present invention, it is possible to protect the membrane in the display area from external pressure and prevent the intrusion of dust etc. without increasing the thickness of the liquid crystal panel.

Further, by disposing the polarizing plate between the membrane and the transparent protective member, it is possible to use an inexpensive and highly accurate material for the transparent protective member, improve the manufacturing yield and reduce the manufacturing cost. You can

Furthermore, by integrating the transparent protective member with the outer frame, the manufacturing process is simplified and the number of parts is reduced.
It is possible to further reduce the manufacturing cost.

As described above, according to the present invention, it is possible to provide a small liquid crystal display device at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal panel according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a manufacturing process of the liquid crystal panel of the first embodiment of the present invention.

FIG. 3 is a sectional view of a liquid crystal panel according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a liquid crystal panel according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a conventional liquid crystal panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal drive element layer 2 Transparent insulating layer 3 Liquid crystal drive circuit board 4 Sealing material 5 Liquid crystal 6 Transparent protective member 7 Adhesive 8 Recess 9 Counter substrate 10 Color filter layer 11 Transparent electrode 12 Alignment film 13 Etching resistant mask material 14 Opaque Substrate 15 Transparent substrate 16 Vacuum chuck 20, 20 'Polarizing plate 21 Outer frame

Claims (4)

[Claims] 1. A liquid crystal is provided between a liquid crystal driving circuit substrate having a liquid crystal driving element layer via a transparent insulating layer on an opaque substrate having a hollowed-out display region, and a counter substrate having a transparent electrode on the transparent substrate. A transmission type liquid crystal display device having a sandwiched liquid crystal panel, wherein a transparent protective member is dropped and fixed so as not to contact the transparent insulating layer in the recess formed by the hollowing. Characteristic liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the transparent protective member is a molded body of acrylic resin. 3. The liquid crystal display device according to claim 1, wherein the transparent protective member also serves as a protective outer frame of the liquid crystal panel. 4. The liquid crystal display device according to claim 1, further comprising a polarizing plate disposed between the transparent member and the transparent insulating layer.