JPH0455816A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow the displaying of plural kinds of display images and high- grade color displaying by including a pair of light transparent substrates, plural color selecting members and plural display electrodes. CONSTITUTION:This display device includes a pair of the light transparent substrates 22a, 22b provided on both sides of a liquid crystal layer and the plural color selecting members 24 which are provided over the entire surface on one side in the thickness direction of the light transparent substrates 22a, 22b and select the transmitted light respectively to any one color among plural kinds of predetermined color. The device also includes the plural display electrodes 23, 26, 28 which are provided within the display region on the liquid crystal layer side of the light transparent substrates 22a, 22b and have the light transparency respectively formed in the range corresponding to the plural color selecting members 24 selected in accordance with the predetermined colors to be displayed in the display region. Two kinds of display screens are displayed in this way without laminating the two liquid crystal display elements and the diversity and versatility of the display of the color liquid crystal display device are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color liquid crystal display device that can display a plurality of types of display images in color.

BACKGROUND OF THE INVENTION FIG. 9 is a sectional view of a conventional segment type color liquid crystal display device 1. A color filter 5 is provided over almost the entire surface of the transparent glass substrate 4a by a method such as a printing method or an electrode coloring method, and a plurality of segment electrodes 6 are provided on the color filter 5. It is formed. The color filter 5 is formed, for example, in a band shape in a direction parallel to the plane of the drawing in FIG. Arranged. The segment electrode 6 includes red electrodes corresponding to the red filter, green filter, and blue filter, respectively;
It consists of an electrode for green color and an electrode for blue color.

A plurality of common electrodes 8 are formed on one surface of the transparent glass substrate 4b over an area including a display area corresponding to the segment electrodes 6, and an alignment film 7b is formed thereon. The glass substrates 4a, 4b are arranged such that the surfaces on which the alignment films 7a, 7b are formed face each other, and the twisted nematic liquid crystal layer 9 is formed on the glass substrates 4a, 4b.
and is sealed with a sealing resin 10.

Moreover, a vague light plate 11.1.2 is provided on the surface of the glass substrates 4a, 4b on the opposite side from the liquid crystal layer 9, respectively.

Here, the polarizing plates 11 and 12 are arranged so as to be parallel Nicols, so that light does not pass through the liquid crystal layer 9 when no voltage is applied, thereby performing a so-called normally black display. By applying a voltage to a desired electrode among the three electrodes constituting the segment electrode 6, a desired color is displayed in the display area corresponding to the segment electrode 6. For example, if voltage is applied only to the red electrode, red will be displayed in the display area, and if voltage is applied to the red and green electrodes, yellow will be displayed by mixing red and green light. It can be carried out. Furthermore, white display can also be performed by applying voltage to all the electrodes: the red electrode, the green electrode, and the blue electrode.

Problems to be Solved by the Invention The display image of the segment type color liquid crystal display device 1 described above is determined by the shape of the segment electrodes 6, and cannot be changed after the color liquid crystal display device 1 is manufactured. inferior in terms of

A liquid crystal display device in which liquid crystal display elements are stacked is considered as a method of increasing the number of displayed images, but this requires two liquid crystal display elements, which poses the problem of making the liquid crystal display device thicker or heavier. .

Moreover, since the color filter 5 is strip-shaped, when combining color filters of different colors to display a color different from that of the filter, the degree of color mixing relative to visual observation,
There is a problem that the clarity of colors decreases and the display quality deteriorates.

An object of the present invention is to provide a color liquid crystal display device that can display a plurality of types of display images and can perform high-quality color display.

Means for Solving the Problems The present invention comprises a pair of light-transmitting substrates provided with a liquid crystal layer in between, and a plurality of light-transmitting substrates provided over the entire left side in the thickness direction of the light-transmitting substrates to predetermine transmitted light. a plurality of color selection members each selecting one of the different colors as one color; and a plurality of color selection members provided in a display area on the liquid crystal layer side of the light-transmitting substrate, each of which corresponds to a predetermined color to be displayed in the display area. The color liquid crystal display device is characterized in that it includes a plurality of display electrodes having translucency and each formed in a range corresponding to the plurality of color selection members to be selected.

Function According to the present invention, normally black display with a black background can be performed by preventing light from passing through the color liquid crystal display device when no voltage is applied. Here, one display electrode is formed corresponding to a predetermined shape and a color selection member of a desired color, and by applying a voltage to this display electrode, light can be transmitted through the liquid crystal layer. can. This transmitted light is selected as one predetermined color by the color selection member, and thereby the shape corresponding to the display electrode and the predetermined color are displayed on the liquid crystal display device.

Further, by forming another display electrode in a shape different from the predetermined shape and corresponding to the desired color selection member, a shape different from the predetermined shape is displayed on the liquid crystal display device.

At this time, further different colors can be displayed by individually forming display electrodes corresponding to multiple types of color selection members and combining multiple types of colors selected by the color selection members.

In addition, since the color selection member is provided over the entire surface of the transparent substrate, even if there is light leakage from the liquid crystal layer when no voltage is applied to the display electrodes, the color liquid crystal display device The same color is displayed over the entire surface, that is, the color that is a combination of the colors selected by each color selection member is displayed, and it is prevented that only a portion has a different color, thereby improving the display quality.

Furthermore, by arranging the color selection members in a matrix or mosaic pattern, when a plurality of colors are combined, the degree of mixing of the displayed colors to the visual sense is greatly improved, and the display quality is improved.

In this way, it is possible to display a plurality of types of different display images (shapes) in different colors, thereby providing display diversity.

Embodiment FIG. 1 is a sectional view of a color liquid crystal display device 21 which is an embodiment of the present invention. The color liquid crystal display device 221 includes transparent substrates 22a and 22b made of glass, plastic, etc.
A transparent electrode (first segment electrode) 23 is provided on one surface of the transparent substrate 22a in an area corresponding to the shape to be displayed.
is formed. Further, a color filter layer 24 is formed on the glass substrate 22a on which the first segment electrode 23 is formed. The color filter layer 24 is composed of, for example, three color filters arranged in a matrix, a red filter, a green filter, a blue filter, and a black light shielding layer, and is formed on the glass substrate 22 by a printing method or the like.
One surface of a is formed over almost the entire surface.

On the surface of the color filter layer 24, the color filter layer 2
4, to prevent deterioration of the color filter layer 24 during formation of the second segment electrode 26, which will be described later, and to improve the adhesion of the second segment electrode 26.
Overcoat layer 25 is formed. After forming the overcoat layer 25, a transparent mold a is formed by sputtering or the like.
i (second segment electrode) 26 is formed in a region corresponding to the shape to be displayed. Furthermore, on the surface there is an alignment film 2.
7a is formed.

A transparent electrode (common electrode) 28 is formed on one surface of the transparent substrate 22b in a region including at least the first segment electrode 23 and the second segment electrode 26, and an orientation M27b is further formed on the surface.

The transparent substrates 22a and 22b each have an alignment film 27a.
The liquid crystal layer 29 is interposed between the transparent substrates 22 a and 22 b and sealed with a sealant 30 .

On the surfaces of the transparent substrates 22a and 22b opposite to the liquid crystal layer 29, polarizing plates 31 and 32 are respectively arranged so as to form parallel Nicols.

FIG. 2 is a plan view showing an example of arrangement of segment electrodes in the color liquid crystal display device 21. FIG. As shown in FIG. 2, for example, the first segment electrode 23 is formed in a rectangular shape, and the first segment electrode 23 formed in the rectangular shape is
They are arranged so that the characters ``日'' are used to form the character ``日'', and for example, two characters ``日'' are arranged side by side. Also,
The second segment electrode 26 is formed in a shape representing, for example, a plant leaf.

FIG. 3 is an enlarged plan view showing the structure of the color filter layer 24, and FIG. 4 is a sectional view showing the structure of the color filter layer 24. The color filter layer 24 has red, green,
It is formed by arranging blue filters in a matrix or mosaic pattern. In FIGS. 3 and 4, the red filter is designated by the reference numeral R, the green filter is designated by the reference numeral G, and the blue filter is designated by the reference numeral B.

The sizes of filters R, G, and B are so minute that they cannot be discerned with the naked eye.

- As an example, length L1 = 330 μm and width L2 = 80
.mu.m rectangular filters R, G, and B are used, and the spacing L3 between the filters is selected to be 30 .mu.m. Therefore, three types of filters R, G, and B are lined up in the width direction A2 of the filter.
The area formed by is 330J1m x 330μm
becomes a square.

The spacing L3 between the filters is determined by the accuracy of color filter production such as photoprocessing, and is generally 15 μm to 15 μm.
It is 40 μm.

The filter arrangement is R-G- in the width direction A2 of the filter.
The permutation of B is repeated, and R-
The BG permutation is repeated.

The shapes of the filters R, G, and B may be square or other shapes.

Moreover, between each filter R, G, and B, a black light shielding layer 40 is provided.
is formed. The light shielding layer 40 is made of chromium (Cr), black pigment, or the like.

FIG. 5 is an enlarged plan view of the first segment electrode 23. The first segment electrode 23 is a red type ffI S r
, a green electrode Sg, and a blue type ISB. The electric currents isr, Sg, and Sb are filters R, Sg, and Sb in the display area.
Formed in each area corresponding to G and B, polyelectric 1s
r, Sg, and Sb are transparent conductors 141r as signal lines,
41g and 41b, respectively. In this way, the electrodes Sr, Sg, S corresponding to filters of the same color
By sequentially connecting b and arbitrarily selecting the electrode to which voltage is applied, red, yellow, green, light blue (cyan),
Seven colors, blue, white, and pink (magenta), can be displayed within the target display area.

The second segment electrode 26 also has a first segment electrode 41i2.
It has the same configuration as 3.

FIG. 6 is a block diagram showing the electrical configuration of the color liquid crystal display device 21. As shown in FIG. In the display screen of the color liquid crystal display device 21, a plurality of first segment electrodes 23 are arranged, for example, as shown in FIG.
Two second segment electrodes 26 are arranged to form the characters ``日'' and are formed into a shape representing, for example, a leaf of a plant. Here, the first segment electrode 23 and the second segment electrode 26 are respectively constituted of a red electrode Sr, a green electrode Sg, and a blue electrode sb, as shown in FIG. 5 described above. Further, the common electrode 28 is connected to the first segment electrode 23 and the second segment electrode 26.
is placed in the area that includes the display area corresponding to.

The first segment electrodes 23 are connected to the signal lines 11 to 1, respectively.
The second segment tffi26 is connected to the second segment electrode drive circuit 14b via a signal line 18,
Furthermore, the common electrode 28 is connected to the common electrode drive circuit 15 via a line 19. Signal lines 11-19
Transparent as a signal line, ie when voltage is applied so that there is no effect on the display! The poles are placed so that they cannot be seen. Signal line! 1 to 18 are three transparent electrodes 4.1r and 41, respectively, as shown in FIG.
g, 41bF.

First and second segment electrode drive circuit 14. a14
b and the common electrode drive circuit 15 are connected to the display control circuit 16.
are connected to the first and second segment electrodes 23 . based on display control signals given from the display control circuit 16 .
A voltage is applied to 26 and common electrode 28.

With reference to FIGS. 1 to 5, cases in which so-called normally white display and normally black display are performed in the color liquid crystal display device 21 will be described. Here, liquid crystal layer 2
The two liquid crystal molecules closest to the transparent substrate 22b are aligned in the direction perpendicular to the plane of FIG.
The transparent electrode 22a gradually twists to the right as it approaches
It is assumed that the liquid crystal molecules closest to are aligned in a direction parallel to the plane of the paper in FIG.

■Normally white display Normally white display means that when no voltage is applied, light passes through the liquid crystal layer 29 so that, for example, the background color is white, and the liquid crystal layer 29 corresponding to the shape to be displayed is This is a display method that blocks light and displays a desired shape by applying a voltage to change the alignment state of liquid crystal molecules. Therefore, the polarizing plate 32 is arranged so that its polarizing direction is perpendicular to the plane of FIG. 1, and the polarizing plate 31 is arranged so that its polarizing direction is parallel to the plane of FIG. 1. As a result, the light transmitted through the polarizing plate 32 is twisted by 90 degrees by the liquid crystal layer 29, and when the light can be transmitted through the polarizing plate 31, the color filter layer 24 has a fine shape as shown in FIG. It is formed by square filters R, G, and H, and the transmitted light is
White light is created by mixing red, green, and blue light. That is, when no voltage is applied, white is displayed as the background color on the color liquid crystal display device 21.

Liquid crystal molecules in the liquid crystal layer 29 to which a voltage is applied are aligned in the direction of the electric field. Therefore, the directly at-polarized light in the direction perpendicular to the plane of FIG. 1 that has passed through the polarizing plate 31 passes through the liquid crystal layer 29 in an almost unchanged polarized state. Here, since the polarization direction of the polarizing plate 31 is parallel to the plane of FIG. 1, the light that has passed through the two liquid crystal layers cannot pass through the shoulder plate 31. Therefore, for example, if a voltage is applied only to the red electrode Sr constituting the first segment electrode 23, red light is blocked and light blue light (cyan color) is displayed by mixing green light and blue light.

The two liquid crystal layers are voltage applied (ON)/no voltage applied (○FF)
works as a light shutter. Table 1 shows the relationship between the 0N10FF state of the segment electrode, its function as a light shutter, and the display color.

In Table 1, "○" indicates the oven state of the optical shutter, and "." indicates the closed state of the optical shutter.

(Left below) Table 1 As shown in Table 1, when a voltage is applied to the green electrode Sg, green light is blocked and a pink (magenta) color can be displayed by mixing red light and blue light. Moreover, if a voltage is applied to the blue electrode sb, blue light is blocked and yellow can be displayed by mixing red light and green light.

Moreover, if a voltage is simultaneously applied to the red electrode Sr and the green electrode Sg, red light and green light are blocked, and a blue display can be performed. When a voltage is applied to the red electrode Sr and the blue electrode sb at the same time, red light and blue light are blocked, green display can be performed, and the green electrode Sg and the blue electrode t8i! When a voltage is applied to Sb at the same time, a red color can be displayed by blocking green light and blue light. Furthermore, three electrodes Sr, Sg.

When a voltage is applied to sb at the same time, all light is blocked and a black display can be performed.

Transparent electrodes 41r, 4 connecting the first segment to the pole 23
By adjusting the width of the electrodes 1g and 41b, changing the resistance values of the transparent electrodes 41r, 41g, and 41b, and changing the voltages applied to the two liquid crystal layers, it is also possible to display an intermediate color.

Although only the first segment electrode 23 has been described here, when applying a voltage to the pole 26 of the second segment, the second segment can be Electrode 2
The display area corresponding to 6 can display 7 colors.

FIG. 7 is a diagram showing the viewing angle range when normally white display is performed on the color liquid crystal display device 21. 7th
Figure 1) is a diagram showing the viewing angle range when display is performed by applying a voltage to the first segment electrode 23;
) is a diagram showing the viewing angle range when display is performed by applying a voltage to the second segment electrode 26. In FIG. 7, solid line 111, t! 12 each has a contrast CO of 10
shows isocontrast curves. Therefore, the regions surrounded by the equal contrast curves Nil and N12 indicate the viewing angle range in which the contrast Co is 10 or more.

As shown in FIG. 7, the first and second segment electrodes 2
3.26, approximately the same viewing angle range is obtained no matter which segment electrode is used.

■Normally black display Normally black display means that when no voltage is applied, the background color is black so that light does not pass through the liquid crystal layer 29, and when a voltage is applied to the liquid crystal layer 29, light is transmitted. This is a display method that displays a desired shape. Therefore, the clearing plates 31 and 32 are arranged so that the polarization directions are parallel Nicols. That is, the polarizing plates 31 and 32 may be arranged so that the polarizing direction is perpendicular to the plane of the drawing 1, or the polarizing plates 31 and 32 may be arranged so that the polarizing direction is parallel to the plane of the drawing 1. It's okay. As a result, light cannot pass through the liquid crystal layer 29 when no voltage is applied. Therefore, black is displayed on the liquid crystal display device 21 as the background color.

The liquid crystal layer 29 functions as a light shutter by applying/not applying a voltage as in the case of the above-mentioned normally white display. Table 2 shows the relationship between the ○N10FF state of the segment electrode, its function as a light shutter, and the display color. In Table 2, 'OJ' indicates the oven state of the optical shutter, and '.' indicates the closed state of the optical shutter.

Table 2 As shown in Table 2, if a voltage is applied only to the red electrode Sr, red is displayed in the display area.

Furthermore, by applying a voltage to the electrode Sg for green or the electrode sb for blue, green or blue can be displayed in the display area, respectively.

Furthermore, if a voltage is simultaneously applied to the red electrode Sr and the green electrode Sg, a yellow display can be performed by mixing red light and green light. When a voltage is applied to the red @ % Sr and blue lights aisb at the same time, a pink (magenta) display can be made by mixing the red light and blue light, and the green lights & Sg and the blue lights Vi
When a voltage is applied to lSb at the same time, light blue (cyan) display can be performed by mixing green light and blue light.

Furthermore, when voltages are simultaneously applied to the three electrodes Sr, Sg, and Sb, a white display can be performed by mixing red light, green light, and blue light.

In the case of normally black display, the first and second segment electrodes 23.
A transparent electrode 41r connects 26.

By adjusting the electrode widths of 41g and 41b, the resistance values of transparent electrodes 41r, 41g and 41b are changed, and the liquid crystal layer 2
It is also possible to display intermediate colors by changing the voltage applied to 9.

FIG. 8 is a diagram showing the viewing angle range when normally black display is performed on the color liquid crystal display device 21. 8th
Figure (1) shows the viewing angle range when display is performed using the first segment electrode 23, and Figure 8 (2) shows the viewing angle range when display is performed using the second segment electrode 26. The viewing angle range is shown. In Fig. 8, solid line N1B
, /14 are equal contrast curves with a contrast CO of 10, respectively. Therefore, the isocontrast curve 113. The regions each surrounded by N14 indicate a viewing angle range in which the contrast Co is 10 or more.

As shown in FIG. 8, the first and second segment electrodes 2
3.26, the display using either of the segment electrodes provides approximately the same viewing angle range.

As described above, according to this embodiment, it is possible to display two different display images in different colors using only the single-layer color liquid crystal display device 21, and display diversity is realized.

Since the color liquid crystal display device 21 is a one-layer type, the optimum viewing angle direction is determined by the mismatch in the viewing angle direction of the upper and lower liquid crystal display elements that occurs when two types of display images are displayed by stacking two liquid crystal display elements. There is no difference between the upper display element and the lower display element, and the same optimum viewing angle direction can be obtained no matter which display image is displayed.

In addition, since it is a single layer type, the color liquid crystal display device 21 can be made smaller and lighter.

Furthermore, no matter which display mode, normally white display or normally black display, is used, the same viewing angle range is obtained as shown in FIGS. 7 and 8, and color liquid crystal display 2] is advantageous when designing the viewing angle direction.

The color filter layer 24 is a fine rectangular filter R1.
Since it is configured by arranging G and B in a matrix, when displaying different colors by combining multiple types of colors, the mixing degree and color clarity of the displayed colors when visually observed are improved, making it possible to display beautiful colors. can be displayed.

In this embodiment, the color filter layer 24 is formed by filters R, G, and B of three colors, red, green, and blue, but the color filter layer 24 is formed by selecting two desired colors from among the three colors. may be formed. Furthermore, the filters are not limited to the three colors of red, green, and blue, but may be filters of yellow, magenta, cyan, or the like. In this case as well, a two-color filter may be used as described above. Furthermore, the color filter layer 24 may be formed using filters of four or more colors.

In this embodiment, the first segment electrode 12B and the second segment electrode 26 are formed with the color filter layer 24 interposed in the transparent substrate 22a on which the color filter layer 24 is formed. Even if it has a two-layer structure with an insulating film such as silicon nitride interposed therebetween, it is possible to perform two types of display as in the above-described embodiment.

Further, in this embodiment, the common electrode 28 is formed larger than the display shape of the first and second segment electrodes 23 and 26 formed on the transparent substrate 22a, so that electrode portions not related to display are not lit. Although the design is such that no matter which electrode of the second segment electrodes 2B and 26 a voltage is applied, voltage is not applied to any part other than the necessary part, the common t[+28 also has a two-layer structure, with one pair facing each other. Two types of display images may be displayed using the electrodes.

Effects of the Invention As described above, according to the present invention, two types of display screens can be displayed without stacking two liquid crystal display elements, and the display diversity and versatility of a color liquid crystal display device can be improved. This will expand the scope of use of color liquid crystal display devices.

[Brief explanation of drawings]

FIG. 1 shows a color liquid crystal display device 2 which is an embodiment of the present invention.
1, FIG. 2 is a plan view of the color liquid crystal display device 21, FIG. 3 is an enlarged plan view showing the structure of the color filter layer 24, FIG. 4 is a sectional view of the color filter layer 24, and FIG. 6 is a block diagram showing the electrical structure of the color liquid crystal display device 21, and FIGS. 7 and 8 are the viewing angles in the color liquid crystal display device 21. FIG. 9, a diagram showing the characteristics, is a cross-sectional view of a conventional color liquid crystal display device 1. 21... Color liquid crystal display device, 22a 22b-Transparent substrate, 23... First segment electrode, 24... Color filter layer, 26... Second segment electrode, 28
...Common electrode, 29...Liquid crystal layer, 41r, 41g4
1b...Transparent electrode, Sr...Red electrode, Sg...
・Electrode for green color, sb... Electrode agent for blue color Patent attorney Keishi Saikyo Figure +2: OQ +2:00 (2) Co10 6.00 Figure

Claims (1)

[Scope of Claims] A pair of light-transmitting substrates provided with a liquid crystal layer sandwiched therebetween; and a pair of light-transmitting substrates provided over the entire surface of one side in the thickness direction of the light-transmitting substrates, each of which has one of a plurality of colors that predetermines transmitted light. a plurality of color selection members each selecting one color; and a plurality of color selection members provided in a display area on the liquid crystal layer side of the transparent substrate and selected corresponding to a predetermined color to be displayed in the display area. 1. A color liquid crystal display device comprising: a plurality of display electrodes having translucency and each formed in a range corresponding to a color selection member;