JPH083591B2 - Color liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application Various types of color display devices using liquid crystals have been proposed today. Among them, the inner surface of the liquid crystal cell, red,
A color liquid crystal display device in which a color filter layer having a fine pattern of green and blue is formed has a feature that a cell structure is relatively simple and full color display is possible.

The present invention relates to an improvement in a color liquid crystal display device having a red, green and blue fine pattern and capable of full color display.

(B) Conventional Technology As shown in FIG. 5, the conventional color liquid crystal display device Da is
A relief pattern made of gelatin, glue, or casein was formed into a red,
It is configured by combining color filters 9a, 10a, 11a dyed in green and blue, a twisted nematic liquid crystal layer 36a, and two neutral polarizers 37a, 37b.

Another conventional color liquid crystal display device Dc is a color polarizer 9c, 1 in which dichroic dyes are aligned in one direction, as shown in FIG.
It is constructed by combining 0c, 11c and a neutral polarizer 37c (above, Japanese Patent Laid-Open No. 58-7177, Japanese Patent Laid-Open No. 58-1742).
No. 0).

(C) Problems to be solved by the invention In the color liquid crystal display device Da, normally two neutral polarizers 37 are used.
a, 37b are positioned so that their polarization directions (directions of arrow Fa and Fb) are parallel to each other, and no voltage is applied to transparent electrodes 24a and 18a, 19a, 20a to display black, and By applying, the liquid crystal molecules of the picture element are raised in the direction of the electric field, and the color of the color filter itself is displayed. Therefore, by arbitrarily selecting the voltages to be applied to the red, green, and blue picture elements independently, it is possible to display any color on the black background.

However, in this color liquid crystal display device Da, red,
In the case of single color display of green and red, only one-third of the whole can contribute to the display, and there is a problem that only the whole display is dark.

In order to solve this problem, it is possible to perform bright display with excellent contrast by placing a light source on the back side. However, in this case, the merit that the liquid crystal display device generally has low power consumption and can be thinned is impaired because it can be used only by placing a light source on the back, which is not preferable.

In the color liquid crystal display device Dc,
Similar to Da, in the case of monochromatic display of red, green, and blue, there is a problem that only one-third of the whole can contribute to the display. In addition, there is a problem that black cannot be displayed. When there is no electric field, the polarization directions of the linearly polarized light coincide with the absorption axis directions of the color polarizers 9c, 10c, and 11c, so that they are observed as red, green, and blue colors, respectively. Next, when an electric field is applied, linearly polarized light is not absorbed by the color polarizers 9c, 10c, 11c, and is observed as colorless. In the color liquid crystal display device Dc, since an arbitrary color is displayed in white or colorless, the whole becomes bright, but on the other hand, there is a problem that the display contrast is poor.

The present invention has been made in view of the above circumstances,
Provided is a color liquid crystal display device which has a wide display area, a bright display, excellent display contrast, low power consumption, and a thin profile.

(D) Means for Solving the Problems The present invention is a color liquid crystal display device capable of selectively displaying any one of laminated color polarizers or black.

The detailed structure is such that the first and second liquid crystal layers are laminated such that a state in which the polarization direction of incident polarized light is rotated by 90 ° by applying or not applying a voltage or a state in which the incident polarized light is transmitted as it is is selectively set. In the color liquid crystal display device configured to select a plurality of picture elements arranged in each of the first and second liquid crystal layers to display a color image in a picture element unit, a light incident side of the first liquid crystal layer Is provided with a neutral polarizer, the light emission side of the second liquid crystal layer is set as a color display surface, and each of the first and second liquid crystal layers is formed by sandwiching liquid crystal between opposed substrates. A laminate of two pairs of color polarizers having different absorption characteristics and having mutually orthogonal absorption axis directions is superposed on the substrate surface far from the neutral polarizer for each pixel. Of the color polarizers arranged in the liquid crystal layer of Is at least three kinds of red, green, and blue, which are set in a combination in which at least one pitch is shifted, and these are arranged alternately in sequence, and the color polarizer arranged in the second liquid crystal layer Is composed of a combination of colors having a complementary color relationship with each of the three colors, and is set to have a complementary color relationship with the arrangement of the color polarizer laminate arranged in the first liquid crystal layer. And a color liquid crystal display device.

(E) Operation Either of the two color polarizers is selected in the first liquid crystal layer and is absorbed or transmitted in the second liquid crystal layer.

(F) Embodiments The present invention will be described in detail based on the embodiments shown in FIGS. 1 to 4, but the present invention is not limited thereto.

FIG. 1 shows a structural explanatory view of the color liquid crystal display device D. Two cells 4 and 5 are formed by the glass substrates 1, 2 and 2, 3 arranged in parallel. On the glass substrate 2,
Blue, red, and green color polarizers 6, 7, and 8 are stacked, respectively. The absorption axis directions of the color polarizers 6, 7, 8 are in the arrow A direction. The color polarizers 6, 7 and 8 are formed by sticking a uniaxially stretched polyvinyl alcohol film (not shown) on the glass substrate 2 in the direction of the arrow A, and by using blue, red and green dichroic dyes respectively. It is formed by dyeing in a pattern.

On the color polarizers 6, 7 and 8, second-layer color polarizers 9, 10 and 11 which are red, green and blue, respectively, are laminated. The absorption axis direction of the color polarizers 9, 10 and 11 is the arrow B direction, and is in a state orthogonal to the absorption axis direction of the color polarizers 6, 7 and 8. The color polarizers 9, 10 and 11 are made by uniaxially stretching a polyvinyl alcohol film (not shown) on the color polarizers 6, 7 and 8 in the direction of arrow B, and sticking the respective red,
It is formed by dyeing a predetermined pattern using green and blue dichroic dyes.

Color polarizations of yellow, cyan, and magenta, which are complementary to the colors of the color polarizers 6, 7, and 8, respectively, are provided on the glass substrate 3 at positions corresponding to the color polarizers 6, 7, and 8. Child
12,13,14 are stacked. The absorption directions of the color polarizers 12, 13, 14 are the same as the absorption directions of the color polarizers 6, 7, 8 and are in the arrow C direction. The color polarizers 12, 13, 14 are made by attaching a uniaxially stretched polyvinyl alcohol film (not shown) on the glass yellow plate 3 in the direction of the arrow C, and dyeing it into a predetermined pattern using yellow, cyan and magenta, respectively. To form.

On the color polarizers 12, 13 and 14, color changers 9 and
Cyan, which is complementary to red, green, and blue, which are 10,11 colors,
Second-layer color polarizers 15, 16 and 17 which are magenta and yellow are laminated. The absorption axis directions of the color polarizers 15, 16 and 17 are
It is in the direction of arrow E, and is in a state orthogonal to the absorption axis directions of the color polarizers 12, 13, and 14. Color polarizer 15,16,17
Attach a uniaxially stretched polyvinyl alcohol film (not shown) on the color polarizers 12, 13, 14 in the direction of arrow E,
It is formed by dyeing a predetermined pattern using cyan, magenta, and yellow dyes, respectively.

The color polarizers 6, 7, 8 of the first layer and the color polarizers 9, 10, 11 of the second layer on the glass substrate 2 are shifted in color by one pitch. Similarly, the color polarizers 12, 13, 14 of the first layer and the color polarizers 15, 16, 17 of the second layer on the glass substrate 3 are shifted by one pitch.

18,19,20,21,22,23 are transparent electrodes. Transparent electrode 18,
19, 20, 21, 22, 23 are formed by forming a transparent conductive film by low temperature sputtering and then etching it into a predetermined pattern.

Further, 24 and 25 are transparent electrodes 18, 19, 20 and 21, 2 respectively.
It is a transparent electrode corresponding to 2,23.

26,27,28,29,30,31 are transparent electrodes 24 and 18,19,2 respectively
It is a power source for applying a voltage between 0 and 25 and 21, 22, and 23.

 32, 33, 34, and 35 are liquid crystal molecule alignment films.

The twisted nematic liquid crystal 36 is injected into the cells 4 and 5 and is sealed by a seal (not shown).

37 is a neutral polarizer disposed on the incident light side of the cell 4. The polarization direction of the neutral polarizer 37 is the arrow F direction. That is, the polarization direction of the neutral polarizer 37 is
The relationship is orthogonal to the absorption axis directions of 1,15,16,17 and parallel to the absorption axis directions of the color polarizers 6,7,8,12,13,14.

The color liquid crystal display device D is configured as described above, and its operation will be described below.

FIG. 2 shows an example in which red monochromatic display is performed. Transparent electrode
Voltage is applied between 19,24 and 23,25. The incident light (arrow L) is deflected by the neutral polarizer 37 in the direction of arrow F, then passes through the glass substrate 1, the transparent electrode 24, and the liquid crystal molecule alignment film 32 and enters the layer of the liquid crystal 36 of the cell 4. Between the transparent electrodes 18, 24 and 20, 24, the light is twisted by 90 ° and reaches the transparent electrodes 18, 20 respectively. Between the transparent electrodes 19 and 24, the light reaches the transparent electrode 19 without being twisted.

The light that has reached the transparent electrode 18 enters the color polarizer 9 and is colored red. In the lower layer color polarizer 6, the polarization direction of the light turned red in the color polarizer 9 and the absorption axis direction of the color polarizer 6 are orthogonal to each other, and the light is transmitted as it is without any influence. The red light transmitted through the color polarizer 6 passes through the glass substrate 2, the transparent electrode 25, and the liquid crystal molecule alignment film 34 and advances to the cell 5, where it is twisted by 90 ° and the polarization direction is changed by 90 °.
It reaches the transparent electrode 21 by being twisted by only °. The light reaching the transparent electrode 21 proceeds to the color polarizer 15, but since the polarization direction of the light at this time and the absorption axis direction of the color polarizer 15 are orthogonal and different, the light is absorbed by the cyan color. Without passing through, the light passes through the color polarizer 15 and goes to the color polarizer 12 as it is. Although the polarization direction of the light traveling to the color polarizer 12 and the absorption axis direction of the color polarizer 12 are parallel,
Is yellow, red light is transmitted as it is, and is observed as red below the glass substrate 3.

The light that reaches the transparent electrode 20 enters the color polarizer 11 and is colored blue, and is transmitted as it is by the color polarizer 8 to the cell 5
Go to. This light that has proceeded to the cell 5 reaches the transparent electrode 23 without being twisted because electricity is applied between the transparent electrodes 23 and 25, and proceeds to the color polarizer 17. In the color polarizer 17, the blue light is absorbed and blocked due to the yellow color of the color polarizer 17 which is in a complementary color relationship with the blue color, and thus black is observed below the glass substrate 3.

The light that reaches the transparent electrode 19 travels to the color polarizers 10 and 7, but the color polarizer 7 having the same polarization direction and the same absorption axis direction.
Is colored red and the process proceeds to cell 5. The red light from the color polarizer 7 is twisted by 90 ° in the cell 5, and the magenta color polarizer 16 is transmitted as it is. Further, in the cyan color polarizer 13 having a complementary color relationship with the red color, since the polarization direction is orthogonal to each other, the color polarizer 13 directly transmits the color polarizer 13 without being absorbed, and is observed to be red below the glass substrate 3. It

As described above, the color liquid crystal display device D displays a red color in two-thirds of the entire display portion and has a large display area. Therefore, the screen is bright and the contrast is excellent. Therefore, since the light source is not specially provided, the power consumption and the thin shape are ensured unchanged.

FIG. 3 shows an example in which red is displayed on the left side, green is displayed on the center, and black is displayed on the right side. Transparent electrode 23,25
A voltage is applied between the two and light (arrow L) is incident from above the neutral polarizer 37. On the left side, red light is observed below the glass substrate 3 as in FIG. In the middle,
The light is colored green because the absorption axis direction of the color polarizer 10 is the same as the polarization direction of the color polarizer 10 and the light is colored as it is because the absorption axis direction and the polarization direction of the color polarizer 7 are different. Pass through and proceed to cell 5. The light is twisted by 90 degrees in the liquid crystal 36 of the cell 5, but the twisted polarization direction is orthogonal to the absorption axis direction of the color polarizer 16, so that the green light is absorbed in the color polarizer 16. Without passing through, it goes to the color polarizer 13. In the color polarizer 13, green light has no complementary color relationship with cyan, so that green light is transmitted as it is and green light is observed below the glass substrate 3. On the right side, as in the case shown in FIG. 2, it is displayed in black. Here, if the color polarizers 9, 10 and 11 are made extremely fine, yellow can be observed below the glass substrate 3 due to additive color mixing.

FIG. 4 shows an example in which red is displayed on the left, green is displayed in the center, and blue is displayed on the right. Light (arrow L) is incident from above the central polarizer 37 with no voltage applied.
On the left side and the center, red and green are respectively observed under the glass substrate 3 as shown in FIG. On the right side, the light is colored blue due to the polarization direction of the light in the color polarizer 11 being the same as the absorption axis direction of the color polarizer 11, and proceeds to the color polarizer 8. Since the absorption axis direction of the color polarizer 8 and the polarization direction of the blue light are different, the blue light is transmitted as it is and advances to the cell 5, where it is twisted by 90 ° by the liquid crystal 36 and reaches the color polarizer 17. Since the polarization direction of blue light is different from the absorption axis direction of the color polarizer 17,
The blue light passes through the color polarizer 17 without being absorbed, and blue is observed below the glass substrate 3.
Here, if the color polarizers 9, 10 and 11 are made extremely fine,
A white color can be observed below the glass substrate 3 due to the additive color mixture.

In addition to the example described above, transparent electrodes 24 and 18, 19, 20, and 25 and 2
Full color display is possible by applying or not applying a voltage between 1, 22 and 23.

(G) Effect of the Invention The present invention provides a color liquid crystal display device having a large display area, bright display, and excellent display contrast without deteriorating the features of the liquid crystal display device that consumes less power and is thinner. Is.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention,
FIG. 4 is a structural explanatory view showing the operation of this embodiment, and FIGS. 5 to 6 are equivalent to FIG. 1 of the conventional example. D: Color liquid crystal display device, 1, 2, 3 ... Glass substrate, 4,5
...... Cell, 6,7,8,9,10,11,12,13,14,15,16,17 …… Color polarizer, 36 …… Liquid crystal.

Claims (1)

[Claims] 1. A first liquid crystal layer and a second liquid crystal layer, wherein a state in which a polarization direction of incident polarized light is rotated by 90 ° by applying or not applying a voltage or a state in which incident polarized light is directly transmitted is selectively set, is laminated. In the color liquid crystal display device for displaying a color image in units of picture elements by selecting a plurality of picture elements arranged in each of the first and second liquid crystal layers, Is provided with a neutral polarizer, the light emitting side of the second liquid crystal layer is set as a color display surface, and the liquid crystal is sandwiched between opposed substrates. Is a stack of two pairs of color polarizers having different absorption characteristics and having mutually different absorption axis directions orthogonal to each other, and the stack is arranged for each pixel on the substrate surface far from the neutral polarizer. The laminated body of the color polarizer arranged in the liquid crystal layer is A stack of the color polarizers, which are composed of at least three kinds of three colors of red, green, and blue which are shifted by at least one pitch, and which are sequentially and alternately arranged, and which are arranged in the second liquid crystal layer. The body is composed of a combination of colors having a complementary color relationship with each of the three colors, and is set in a complementary color relationship with the arrangement of the laminate of the color polarizers arranged in the first liquid crystal layer. A color liquid crystal display device characterized by the above.