JPH07152018A - Ferroelectric liquid crystal display device - Google Patents

Abstract

PURPOSE:To surely suppress vibration transmission to a cell regardless of long- term use and to suppress the temp. rise of the cell at the time of driving. CONSTITUTION:Even if vibration and impact from the outside are transmitted to a fixing frame 6, these vibrations, etc., are attenuated by coiled springs 23 and are hardly transmitted to the cell 2. These coiled springs 23 are made of metal and are, therefore, less degraded in modulus of elasticity accompanying the long-term use. The effect of attenuating the vibrations, etc., is consequently sustained. Since the spacing between the fixing frame 6 and a fixing plate 3 is not closed, air around the cell 2 is circulated by convection through this spacing and the temp. rise of the cell 2 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a ferroelectric liquid crystal display device, and more particularly to a mechanism for relaxing vibration transmission to a cell.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices using a ferroelectric liquid crystal have been disclosed in Japanese Patent Laid-Open No. 2-93425 and Japanese Patent Laid-Open No. 3-93425.
Various proposals have been made in Japanese Patent Publication No. 203773, Japanese Unexamined Patent Publication No. 4-106529, etc. FIG. 1 shows an example thereof.

This liquid crystal display device 1 mainly comprises a cell 2, a fixing plate (cell support) 3 for supporting the cell 2,
And a backlight 5, which are configured by supporting them with a fixed frame 6.

The cell 2 among them is constructed by sandwiching a ferroelectric liquid crystal between two glass substrates, on which transparent electrodes are formed and an alignment treatment is applied. There is. The fixed plate 3 is formed of, for example, a plastic or metal plate, and the fixed plate 3 has an opening that is slightly smaller than the cell 2. A rubber adhesive 7 is applied around the opening of the fixing plate 3, and the cell 2 is attached so that the opening is closed by the adhesive 7. An upper polarizing plate 9 and a lower polarizing plate 10 are attached to both upper and lower surfaces of the cell 2. A flexible printed wiring film 11 is connected to the take-out electrode of the cell 2, and a circuit board 12 for driving the cell 2 is electrically connected to the printed wiring film 11.
The circuit board 12 is fixed to the fixing plate 3 described above by screws or the like (hereinafter, these fixing plates 3,
Cell 2, upper and lower polarizing plates 9 and 10, printed wiring film 1
1. The circuit board 12 is generically referred to as "display unit U").

The display unit U is supported by the fixed frame 6 in a suspended state, because the entire peripheral edge of the fixed plate 3 is adhered to the fixed frame 6 by the rubber adhesive 13, and the fixed frame 6 is fixed. A backlight 5 is attached to the lower part. A diffusion plate 8 is attached to the surface of the backlight 5. The backlight 5, the fixed frame 6, the fixed plate 3, and the cell 2 form a substantially closed space 15. Even if the cell 2 vibrates to some extent, the vibration is immediately caused by the air damper effect of the substantially closed space 15. It is designed to decay. Further, a display plate 17 is attached to the upper portion of the fixed frame 6 via a cover 16, and the display plate 17 protects the cells 2 and the like.

In the liquid crystal display device 1 having such a structure, as described above, the rubber-based adhesive 13 having elasticity is interposed between the fixed frame 6 and the fixed plate 3, and the fixed plate 3 and Since the rubber-based adhesive 7 having elasticity is also interposed between the cell 2 and the cell 2, shocks and vibrations from the outside are attenuated by these adhesives 13 and 7, and the shock or the like is transmitted to the cell 2. It has the advantage that it is hard to be done. Also,
Since the entire periphery of the fixed plate 3 is sealed by the rubber adhesive 13 and the backlight 5, the fixed frame 6, the fixed plate 3 and the cell 2 form a substantially sealed space 15, the cell 2 vibrates to some extent. The vibration is immediately attenuated by the air damper effect of the substantially closed space 15. Therefore, the deflection of the cell 2 is suppressed to a minimum, the occurrence of alignment defects, which is a problem peculiar to the ferroelectric liquid crystal cell, is suppressed, and the deterioration of display quality is also prevented.

[0007]

By the way, in the above-described liquid crystal display device 1, the display unit U is supported by the rubber-based adhesive 13 provided in close contact with the entire peripheral edge of the fixing plate 3. Since the adhesive generally deteriorates due to long-term use and its elastic modulus decreases, vibration and the like are not completely attenuated as the elastic modulus decreases,
The cell 2 has a problem that an alignment defect occurs. Such a problem is not so remarkable when the cell 2 has a small size of 15 inches or less, but it becomes quite remarkable in the cell 2 having a large screen size exceeding 20 inches.
In particular, such a large screen size cell is generally used in an upright state such as a word processor used on a desk. In such a case, the total weight of the display unit U is rubber. Since it is not dispersed in the entire system adhesive 13 but concentrates in a specific portion (the lower portion of the cell 2 or the fixing plate 3),
There is a problem that the adhesive 13 in the specific portion is easily deteriorated.

On the other hand, when the liquid crystal display device is driven, the cells 2, the backlight 5, the circuit board 12 and the like generate heat.
However, since the air around the cell 2 does not convect, the temperature of the cell 2 rises and the display quality deteriorates.

Therefore, according to the present invention, by supporting the cell support and the cell in a suspended state by a spring, the effect of vibration damping is maintained, and the convection of air around the cell is enabled to suppress the temperature rise of the cell. An object of the present invention is to provide a dielectric liquid crystal display device.

[0010]

The present invention has been made in view of the above circumstances, and a pair of substrates having electrodes formed on the surfaces thereof are opposed to each other and bonded together, and a ferroelectric property is provided between the pair of substrates. A cell that holds the liquid crystal, a cell support that supports the cell, and a fixed frame that supports the cell support,
In the ferroelectric liquid crystal display device including, a spring is interposed between the fixed frame and the cell support, and the cell support and the cell are supported in a suspended state. To do. In this case, it is preferable that the spring is formed by molding a rod-shaped metal material into a coil shape or a hairpin shape. Further, the spring may be formed by forming a flat metal material into a U shape or a hairpin shape. Further, the spring may be made of resin. Still further, the spring may be made of metal and resin.

[0011]

According to the above construction, even if an external vibration or shock is transmitted to the fixed frame, the vibration or the like is attenuated by the spring and is difficult to be transmitted to the cell support or the cell. Moreover, the elastic modulus of the spring does not decrease even after long-term use, and thus the effect of damping vibration can be maintained. Furthermore, since the spring interposed between the fixed frame and the cell support does not seal the gap space, it does not interfere with air convection.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display device 20 according to this embodiment, as shown in FIG. 2, a plurality of metallic coil-shaped springs 23, ... Between the fixed frame 6 and the fixed plate (cell support) 3.
Is installed. These coiled springs 23, ...
As shown in FIG. 3, the fixed plate 3 is arranged on all sides to support the display unit U including the fixed plate 3 and the cells 2 in a suspended state. Further, since the coiled springs 23, ... Do not close the gap between the fixed frame 6 and the fixed plate 3, the space 25 formed by the cells 2, the backlight 5, etc. is not sealed.

According to this embodiment, elastic coil-shaped springs 23, ... Are interposed between the fixed frame 6 and the fixed plate 3, and also between the fixed plate 3 and the cell 2. Since the rubber-based adhesive 7 which also has elasticity is interposed, external shocks and vibrations are attenuated by the coil springs 23, ... And the adhesive 7, and the shocks and the like are less likely to be transmitted to the cell 2. Has the advantage.

Further, since the coiled springs 23, ... Are made of metal and are not deteriorated or lowered in elastic modulus even after long-term use, the effect of attenuating vibrations is maintained,
Generation of alignment defects in the cell 2 can also be suppressed. Such an effect is particularly effective for a large screen size in which the cell 2 exceeds 20 inches. Further, as shown in FIG. 2, when the cell 2 is used in an upright state, the total weight of the display unit U is not distributed to the entire coil-shaped springs 23 ,. The same effect can be obtained even when concentrated on. When the cell 2 is used upright in this way, the coil-shaped springs 23, ... Can be supported simply by arranging the coil springs 23, ...

Further, since the coiled springs 23, ... Do not block the gap between the fixed frame 6 and the fixed plate 3 structurally,
Space 2 formed by cell 2 and backlight 5
5 is not hermetically sealed. Therefore, cell 2
The convection of air around is not disturbed, the temperature rise can be suppressed regardless of the heat generation of the cell 2 and the like, and the display quality is not deteriorated. Further, since it is not necessary to seal the air around the cell, the structure is simplified, and the liquid crystal display device 2
The manufacturing cost of 0 can be reduced.

The applicant of the present invention conducted an experiment for confirming heat dissipation and impact resistance of the liquid crystal display device. Specifically, a constant voltage (V _OP 25V) was applied under the same environmental temperature to drive the cell 2, and the temperature (temperature rise value) of the upper portion of the cell 2 at that time was measured. Further, the liquid crystal display device was dropped to observe whether or not the alignment deterioration occurred, and the maximum impact value when the alignment deterioration occurred was determined. For comparison, the liquid crystal display device 1 having the conventional structure shown in FIG. 1 was similarly measured for temperature and impact value. Table 1 shows the experimental results. From this, according to this embodiment, the temperature rise of the cell 2 can be suppressed to 19.5 ° C., which is 6 ° C. lower than the conventional example, and the impact resistance is 80 G, which is 20 G higher than the conventional example. I understand.

[0018]

[Table 1] In the above-mentioned embodiment, the material of the spring supporting the display unit U is made of metal, but of course it is not limited to this, and if the material deterioration with time is small,
It may be a resin such as plastic or a composite material in which a metal spring is embedded in the resin. In that case, although the elastic modulus of the spring and the mechanical characteristic values such as the deformation limit are different from those of metal, the size and quantity of the spring, or the fixing frame 6 and the fixing plate 3 are used.
By optimizing various conditions such as the distance between and, the same effect as the metal spring can be obtained. That is, external impacts and vibrations are attenuated, the impacts and the like are less likely to be transmitted to the cell 2, the effect can be maintained even after long-term use, and the occurrence of alignment defects in the cell 2 can be suppressed. . This effect is great for large screen sizes,
It is particularly effective when the cell 2 is used in an upright state.
Further, since the closed space is not formed, the temperature rise of the cells 2 and the like can be suppressed and the display quality does not deteriorate.

Further, in the above-mentioned embodiment, the shape of the spring for supporting the display unit U is the coil shape, but of course the shape is not limited to this, and other shapes may be used. For example, a rod-shaped material may be processed into a hairpin shape, or a flat material may be processed into a U-shape or a hairpin shape.

Further, in the above-mentioned embodiment, the cell 2 and the fixing plate 3 are adhered to each other by the rubber adhesive 7, and the elasticity of the adhesive is utilized to obtain the vibration damping effect. Of course, the present invention is not limited to this, and an elastic member for damping vibration may be interposed between the cell 2 and the fixed plate 3. In that case, adhesion between the elastic member and the cell 2,
The elastic member and the fixing plate 3 may be adhered to each other with an inelastic adhesive.

[0021]

As described above, according to the present invention,
Since the cell support body and the cell are supported in a suspended state by the spring interposed between the fixed frame and the cell support body,
The impact and the vibration from the outside are damped by the spring, and the transmission of the vibration to the cell is suppressed. Therefore, it is possible to realize a display device having a greater buffering effect against mechanical stress such as vibration impact, and it is possible to suppress the occurrence of alignment defects.

Further, since the spring has almost no decrease in elastic modulus even when it is used for a long period of time, the effect of damping vibrations and the like is maintained, and the occurrence of alignment defects in the cell can be suppressed. Such an effect is remarkable in a cell having a large screen size of more than 20 inches, and when the cell is used in an upright state, the total weight of the cell or the like is not dispersed in the entire spring and a specific portion (below the cell or the like) is It is remarkable when concentrated.

Further, the spring interposed between the fixed frame and the cell support does not structurally close the gap between the fixed frame and the cell support. Therefore, the air around the cells convects through the gaps, the temperature rise can be suppressed regardless of the heat generation of the cells and the like, and the display quality is not deteriorated. Further, since it is not necessary to seal the air around the cell, the structure is simplified and the manufacturing cost of the liquid crystal display device can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a conventional liquid crystal display device.

FIG. 2 is a sectional view showing the structure of a liquid crystal display device according to the present invention.

FIG. 3 is a plan view showing the structure of a liquid crystal display device according to the present invention.

[Explanation of symbols]

 1 Liquid Crystal Display Device 2 Cell 3 Cell Support (Fixing Plate) 6 Fixing Frame 7 Rubber Adhesive 13 Rubber Adhesive 20 Liquid Crystal Display 23 Spring (Coil Spring) U Display Unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shutaro Tsuchiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A cell in which a pair of substrates each having an electrode formed on the surface thereof are opposed to each other and bonded to each other, and a ferroelectric liquid crystal is held between the pair of substrates, a cell support for supporting the cell, and A ferroelectric liquid crystal display device comprising: a fixed frame that supports the cell support, wherein a spring is interposed between the fixed frame and the cell support so that the cell support and the cell are in a suspended state. Ferroelectric liquid crystal display device supported by. 2. The ferroelectric liquid crystal display device according to claim 1, wherein the spring is formed by molding a rod-shaped metal material into a coil shape or a hairpin shape. 3. The ferroelectric liquid crystal display device according to claim 1, wherein the spring is formed by forming a flat metal material into a U shape or a hairpin shape. 4. The ferroelectric liquid crystal display device according to claim 1, wherein the spring is made of resin. 5. The ferroelectric liquid crystal display device according to claim 1, wherein the spring is made of metal and resin.