JPH07281196A - Liquid crystal display device and its projection type display - Google Patents

Abstract

PURPOSE:To improve the appearance of the projected images macroprojected on a screen of a projection type display using a liquid crystal display device. CONSTITUTION:Colored spacers 6 and colorless spacers 7 are simultaneously scattered in order to maintain the specified inter-substrate spacing of the liquid crystal display device to be used as the projection type display. Number of black spots as the projected images to be macro-displayed on the screen is decreased by decreasing the colored spacers while the inter-substrate spacing of the liquid crystal display device is maintained constant and, therefore, the projection type display having an improved display grade is provided.

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 and a projection type display using the liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display device, spacers are generally used to keep the thickness of a liquid crystal layer constant. Are these spacers mixed in a sealing material for adhering two glass substrates? Alternatively, it is used by being uniformly dispersed on the surface of the glass substrate.

FIG. 3 is a sectional view showing an example of the configuration of a conventional liquid crystal display device. The transparent electrode layers 2a and 2b for applying a voltage are formed on the inner surfaces of the pair of transparent substrates 1a and 1b, and the sealing material 3 for adhering the other substrate layer 1b to one substrate 1a is screen-printed. In addition, the spacers 5 are substantially evenly scattered on the surface of the substrate 2b on which the other electrode layer 2b is formed, and then the pair of substrates 1a and 1b is kept constant by the spacers 5. Then, the liquid crystal cell is formed by filling the liquid crystal 4 with the sealing material 3 and adhering it with the sealing material 3. At this time, the number of spacers 5 to be dispersed per unit is determined by the size of the liquid crystal display device. It should be noted that one of the substrates 1a and 1b is provided with some other layers, that is, a light-shielding layer, a color filter layer, a protective layer for protecting the light-shielding layer or the color filter layer, and the liquid crystal 4 as necessary. An alignment layer or the like for alignment may be formed, but for simplicity, the electrode layers 2a and 2b are representative and other layers are omitted in the drawing. In the liquid crystal cell thus formed, polarizing plates 6a and 6b are placed on the surfaces of the substrates 1a and 1b on which the electrode layers 2a and 2b are not formed, respectively, to obtain a liquid crystal display device.

Here, the members used for the spacer 5 include
There are conventionally used transparent glass fibers, plastic balls, silica balls, and the like. Further, among these members, colored members that hardly transmit light are also used. The embodiment of FIG. 3 shows an example using a colored member.

As shown in FIG. 3, the left part of the display screen in the liquid crystal display device constructed by using the spacer 5 is the black display part 2.
FIG. 4 shows a display form in which 0 and the white display portion 21 are on the right side.
In the case where the spacer 5 is a transparent member which is not colored, the spacers 5 scattered in the black display portion 20 are apt to stand out as bright spots, and the display that is originally black becomes faint so that the display quality is degraded. On the other hand, in the case where the spacer 5 is a colored member, light leakage due to the spacers 5 scattered in the black display portion 20 is reduced and the display quality is not deteriorated. Further, in the white display portion 21, since it is difficult to identify the member in which the spacer 5 is colored, it is less likely to impair the display quality. An example using such a member in which the spacer 5 is colored is found in Publication No. 3-72969.

FIG. 5 is a schematic view constructed as a projection type display using the liquid crystal display device as shown in FIG.
In FIG. 5, the illuminating means 1 is provided from behind the liquid crystal display device 10.
1, the liquid crystal display device 10 is irradiated with light, an image arbitrarily displayed on the liquid crystal display device 10 is enlarged by an optical system 12 which is a projecting means, and the image is installed in front of the optical system 12 at an arbitrary distance. And project it on the screen 13. However,
Then, only the main members required for the projection type display are described, and the other members are omitted.

[0007]

However, when the liquid crystal display device 10 in which only colored members are scattered as the spacer 5 is used as the liquid crystal display device 10 for forming a projection image of a projection type display, the spacer 5 is used. The colored member used is magnified and projected by the optical system 12 as a projection means, and as a result, when it is displayed in white, it becomes conspicuous as a black dot on the surface of the screen 13 and the display quality as a projection display is degraded. There was a problem of inviting.

[0008] Therefore, an object of the present invention is to solve the above problems, and to improve the display quality of a projection type display by reducing the black dots scattered in the projected image projected on the screen 13. Liquid crystal display device 10
To provide.

[0009]

Means for using the present invention to achieve the above-mentioned object is to provide a spraying quantity per unit which is determined by the size of the liquid crystal display device 10 when spraying the spacers 5. The number of dispersed colored members used as the spacers 5 is reduced without changing, that is, without changing the gap between the substrates 1a and 1b included in the liquid crystal display device 10.

[0010]

Operation: Liquid crystal display device 10 used for projection type display
Is formed by reducing the number of scattered colored members as spacers 5, so that a projected image of the colored members as spacers 5, that is, a black dot is displayed on the screen 13 in which the image displayed in white is enlarged and projected. Can be reduced

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of an embodiment of the present invention. In FIG. 1, a pair of transparent substrates 1a and 1b
The colored spacers 6 and the uncolored spacers 7 are evenly dispersed on one of the surfaces of the electrode layers 2a and 2b formed on the upper side, respectively, and the substrates 1a and 1b are superposed so that the gap between them is constant. Then, the liquid crystal 4 is filled with the sealing agent 3 and the adhesive. At this time, the number of scattered colored spacers 6 and non-colored spacers 7 sandwiched between the substrates 1a and 1b is a unit in which the total number of them is determined by the size of the liquid crystal display device 10. The number of the colored spacers 6 and the non-colored spacers 7 is controlled to be approximately equal to the number of the per unit, and the ratio of the colored spacers 6 and the non-colored spacers 7 to be dispersed is equal to the amount per unit.

Here, a method of spraying the colored spacers 6 and the uncolored spacers 7 will be described. First, as a first method, either the colored spacer 6 or the uncolored spacer 7 is predetermined on the substrate surface of either the transparent substrate 1a or 1b on which the electrode layers 2a and 2b are formed. Is sprayed according to the quantity per unit of, and then the other is also sprayed with a predetermined quantity per unit. At this time, either order may be applied first.

Next, the second spraying method will be described. After the weights of the colored spacer 6 and the non-colored spacer 7 to be used are separately weighed, both are put in the same container and mixed well to form a single spacer member for the substrate 1a.
And the liquid crystal display device 10 on the substrate surface of either 1b.
Disperse the quantity per unit defined by the size of. Liquid crystal display device 10 in which colored spacers 6 and uncolored spacers 7 are scattered by the first and second spraying methods.
Will be created.

As shown in FIG. 1, a liquid crystal display device 10 constituted by interspersing colored spacers 6 and non-colored spacers 7
2 shows a display form in which the left part of the display screen in FIG. 2 is a black display part 22 and the right part is a white display part 23. Since the number of the colored spacers 6 scattered in the white display portion 23 is reduced as compared with the conventional one, the colored spacers 6 are included in the projection image projected by the projection display using the liquid crystal display device 10.
This also reduces the number of black dots, which is effective in improving the display quality of the projection display.

Further, in FIG. 2, when the uncolored spacers 7 are scattered in the black display portion 22 and the quality of the projected image is deteriorated, the transmittance of the uncolored spacers 7 is adjusted to be decreased. It is also possible to use the above spacer member. However, in the white display portion 23, the transmittance of the uncolored spacer 7 may be adjusted to the extent that the spacer member having the adjusted transmittance described above is not recognized as a black dot.

Further, when a two-layer STN type liquid crystal display device composed of a driving liquid crystal cell and a color compensating liquid crystal cell is used as the liquid crystal display device 10 used for the projection type display, the present embodiment will be described with respect to the driving liquid crystal cell. It goes without saying that adopting a configuration in which the colored spacers 6 and the uncolored spacers 7 as shown in FIG. 1 are scattered according to a predetermined number of units is effective in improving the display quality of the projection display.

This concludes the description of the embodiment of the present invention.
With some correction, the colored spacers 6 and the uncolored spacers 7 used in FIGS. 1 and 2 are the same as the substrates 1a and 1a.
It is desirable that the colored spacers 6 and the non-colored spacers 7 have the same diameter because they are dispersed so that the gap between them is constant.

It is desirable that the ratios of mixing the colored spacers 6 and the uncolored spacers 7 are equal.
You may change the ratio which mixes them according to the use of a projection type display.

[0019]

As described above in detail, the present invention reduces the number of the colored spacers 6 scattered in order to make the gap between the substrates 1a and 1b of the liquid crystal display device 10 constant.
Since the black dots due to the colored spacers 6 can be reduced in the projection image projected on the screen 13 on the projection display, it is possible to provide the liquid crystal display device 10 capable of improving the display quality of the projection display. It has a great effect.

Further, as the non-colored spacer 7 mixed with the colored spacer 6, if a member whose transmittance is adjusted so that it is not recognized as a black dot during white display is used,
Since it is possible to reduce the degree of bright spots due to the uncolored spacers 7 when black display is performed, it is possible to provide a projection display with improved display quality.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention and is a sectional view.

FIG. 2 is an explanatory view showing an embodiment of the present invention and is a plan view showing a display form.

FIG. 3 is an explanatory view showing a conventional example and is a sectional view.

FIG. 4 is an explanatory view showing a conventional example, and is a plan view showing a display form.

FIG. 5 is an explanatory view showing a conventional example and is a cross-sectional view showing a configuration of a projection display.

[Explanation of Codes] 5 Spacer 6 Colored Spacer 7 Uncolored Spacer 10 Liquid Crystal Display 22 Black Display 23 White Display

Claims (6)

[Claims] 1. A structure in which a gap between a pair of transparent substrates having an electrode layer formed on the inner surface thereof is kept predetermined, the peripheral portions of the substrates are adhered with a sealant, and a gap between the substrates is filled with a liquid crystal material. In the liquid crystal display device, a colored spacer having a predetermined diameter and a non-colored spacer are scattered at the same time as spacers for maintaining a predetermined gap between the substrates. 2. The liquid crystal display device according to claim 1, wherein the number of the colored spacers and the number of the non-colored spacers dispersed are equalized. 3. The liquid crystal display device according to claim 1, wherein the non-colored spacer has a transmittance changed. 4. A projection display using the liquid crystal display device according to claim 1. 5. A projection display using the liquid crystal display device according to claim 2. 6. A two-layer system comprising a driving liquid crystal cell having an electrode layer formed on the inner surface of a pair of transparent substrates and a color compensating liquid crystal cell for color compensation of the driving liquid crystal cell. A projection display, which is an STN type liquid crystal display device, wherein a two-layer type STN type liquid crystal display device which constitutes the liquid crystal display device according to claim 1 is used as the driving liquid crystal cell.