JPH02123328A - Liquid crystal color display device - Google Patents

Abstract

PURPOSE:To curtail unnecessary manhour for a color display, and also, to obviate the deterioration of a color display characteristic of a visual angle dependency, etc. by containing in advance a colorant into at least one of a pair of oriented layers for inserting and holding a liquid crystal. CONSTITUTION:As for a pair of oriented layers, a colorant is contained in advance into at least one of the oriented layer 15. That is, by containing in advance the colorant, a function for orienting a liquid crystal 2 in the specific direction and a function for bringing an incident light to color display are combined. In such a way, a process for forming a color layer, etc. becomes unnecessary, and a unnecessary manhour for a color display is curtailed. Also, since the oriented layer 15 having a color display function is allowed to adhere closely to a transparent electrode, it does not occur that a color display characteristic of a visual angle dependency, etc. is deteriorated.

Description

[Detailed Description of the Invention] [Summary] A liquid crystal color display device in which at least one of a pair of alignment layers sandwiching a liquid crystal contains a coloring agent in advance so that the alignment layer itself has a color display function. The number of man-hours required for display can be reduced, and color display characteristics can be improved.

[Industrial application field]

The present invention relates to a liquid crystal color display device for performing color display using a liquid crystal panel.

For example, the above-mentioned liquid crystal color display device is required to display characters, numbers, etc. by function on the front surface of an electrical component.

[Conventional technology]

FIG. 3 is an exploded perspective view of a general liquid crystal panel.

- IC is equipped with a liquid crystal panel 7 having a plurality of electrodes according to the shape of characters etc. displayed on the front surface of the electronic equipment. Only shown.

Referring to FIG. 3, the procedure for assembling the liquid crystal panel 7 will be explained. First, a pair of transparent substrates 3 such as glass substrates are coated with ITO (
Transparent electrodes 4 each made of a transparent conductive film such as Indium Tin Oxide are formed. Next, a pair of alignment layers 5 are formed on the transparent electrode 4 to align the molecular axis of the liquid crystal 2 in a specific direction, for example, parallel to the transparent substrate 3.

These alignment layers 5 are obtained by applying an alignment agent such as polyimide onto the transparent electrode 4 by printing or the like, and then rubbing it.

Further, the liquid crystal 2 is sandwiched between the pair of alignment layers 5 with a spacer interposed therebetween. Finally, the liquid crystal panel 7 is completed by arranging two polarizing plates 6 on the outside of each of the transparent substrates 3 so that their polarization planes are perpendicular to each other. In this liquid crystal panel 7, when no voltage is applied between the two transparent electrodes 4, the molecular axes of the liquid crystal 2 are arranged parallel to the transparent substrate 3 and twisted by 90 degrees along the direction of light propagation. Therefore, the polarization plane of the incident light is rotated by 90 degrees along the twist of the liquid crystal 2 and is transmitted as is. On the other hand, when a voltage is applied by the drive power source 10, all the molecular axes of the liquid crystal 2 are aligned in the voltage application direction, so the polarization plane of the incident light does not rotate, so all the incident light is absorbed by the rear polarizing plate 6. No transmitted light occurs.

Therefore, by selectively applying a voltage between the plurality of transparent electrodes 4, desired characters or the like can be displayed due to the contrast of light. Generally, since white light is used as the incident light, only black and white display is possible in this case, but if the liquid crystal panel 7 is provided with a color display function by the following means, color display by liquid crystal becomes possible.

FIG. 4 is a cross-sectional side view of a first example of a conventional liquid crystal color display device. Here, a color filter 8 is newly provided outside the polarizing plate 6.

Therefore, when no voltage is applied between the transparent electrodes 4,
The color filter 8 outputs the incident light as colored transmitted light for displaying a desired color.

FIG. 5 is a cross-sectional side view of a second example of a conventional liquid crystal color display device. Note that from FIG. 5 onwards, the drive power supply 10 (
The description of Fig. 4) is omitted. Here, a color layer 9 containing a coloring agent such as a color dye is coated on the outside or inside of the polarizing plate 6 to form a color polarizing plate 6'. With this color polarizing plate 6', the incident light is outputted as transmitted light of a desired color, similar to the first example (FIG. 4).

FIG. 6 is a cross-sectional side view of a third example of a conventional liquid crystal color display device. Here, a color layer 9 that is thin enough to not affect the original thickness of the liquid crystal 20 is formed by printing or vapor deposition on the inside of the pair of transparent substrates 3, that is, on at least one of the two transparent electrodes 4. .

[Problems to be solved by invention]

As described above, conventionally, a liquid crystal color display device 1 was constructed by newly providing a color filter 8 or a color layer 9 on the outside or inside of the transparent substrate 3. Therefore,
The following problems arise.

In the first example (FIG. 4) and the second example (FIG. 5) of the prior art, it takes time and effort to manufacture the color filter 8 and the color polarizing plate 6', respectively. On top of that,
The color filter 8 and the color polarizing plate 6' are the transparent electrode 4.
Since the liquid crystal display device 1 is not in close contact with the liquid crystal display device 1, the viewing angle dependence becomes strong and color shift tends to occur when the display surface is viewed from an oblique direction.Furthermore, the thickness of the liquid crystal display device l increases. This tendency is particularly noticeable in the first example (FIG. 4).

Even in the conventional third example (Fig. 6), the first example and the second example
As in the example, it takes time and effort to print or vapor deposit the color layer 9 on the transparent electrode 3. In this case, since the color layer 9 is in close contact with the transparent electrode 4, color shift is less likely to occur when viewed from an angle, but on the other hand,
Since the color layer 9 is thin, the thickness of the color layer 9 tends to become uneven due to roughness of the surface of the underlying transparent electrode 4, etc. As a result, the thickness of the alignment layer 5 also becomes non-uniform, and the effective thickness of the liquid crystal 2 varies depending on the location, so the photo-electrical response characteristics etc. vary depending on the location, which may make the display surface difficult to see. .

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a liquid crystal color display device that reduces unnecessary man-hours for color display and does not deteriorate color display characteristics such as viewing angle dependence. This is the purpose.

[Means to solve the problem]

The liquid crystal color display device of the present invention is characterized in that at least one of the pair of alignment layers sandwiching the liquid crystal 2 contains a colorant in advance.

[Function] In the present invention, the role of orienting the liquid crystal 2 in a specific direction by pre-containing a coloring agent in the alignment layer;
It also serves as a color display for incident light.

In this manner, the present invention does not require processes such as forming a color layer, so that unnecessary man-hours for color display can be saved. Moreover, since the alignment layer having a color display function is in close contact with the transparent electrode, color display characteristics such as viewing angle dependence are not deteriorated.

〔Example〕

FIG. 1 is a side cross-sectional view of one embodiment of the present invention. Note that components similar to those described above are denoted by the same reference numerals.

In this case, a coloring agent such as a color dye is mixed in advance with an alignment agent such as liquid polyimide. This mixing operation can be easily performed because the polymer material is in a liquid state. Further, a mixture of the two is formed on the transparent electrode 4 by printing or the like and cured by heat, and then the surface is subjected to a rubbing treatment, thereby completing the process of producing the alignment layer 15 having a color display function.

That is, in one step, the alignment layer 15 made of an alignment agent is formed.
Since the colorant layer and the pseudo color layer made of the colorant are formed at the same time, the manufacturing cost is reduced. The thickness of the alignment layer 15 is the same as the thickness of the conventional alignment layer 5 (FIGS. 4 to 6), and is thinner than the color layer 9 in the third conventional example (FIG. 6). Since it is not necessary, the alignment layer 15
That is, even if a pseudo color layer is formed, the thickness of the liquid crystal 2 will not become non-uniform. Therefore, variations in the optical-electrical response characteristics of the liquid crystal 2 due to location do not occur.

2A and 2B are diagrams showing a full-color display device according to an embodiment of the present invention, with FIG. 2A being a side cross-sectional view, and FIG. 2B being a plan view. In addition, here,
Only the transparent electrode 4 and alignment layer 15 on the transparent substrate 3 are shown.

Referring to FIGS. 2A and 2B, a procedure for assembling a full-color display device will be described. A plurality of transparent electrodes 4 are arranged in a dot shape on a transparent substrate 3. First, a mixture of three types of color dyes, red, blue, and green, which are the three primary colors of light, is separately mixed with an alignment agent. Next, a mixture of these three types is formed uniformly on the transparent electrode 4 by printing or the like. That is, a red alignment layer 15R1, a blue alignment layer 15B, and a green alignment layer 15 each containing red, blue, and green color dyes.
If G is arranged in the same pattern, a full color display device can be realized. In this pull-color display device, portions of the transparent electrodes 4 for red, blue, and green that are close to each other (R, B, and G within the dashed-dotted line in FIG. 2B) form one pixel 16 for full-color display. do. Furthermore, if a voltage is selectively applied to the transparent electrode 4 in which a plurality of pixels 16 are assembled, a desired figure or the like can be displayed in full color. In this case, the process of forming the color layer 9 in the conventional example does not need to be newly provided, so that a full-color display device can be realized more easily than in the conventional example.

〔Effect of the invention〕

As described above, according to the present invention, a liquid crystal color display device can be realized through the same assembly process as a black and white liquid crystal panel, so that unnecessary man-hours for color display can be saved and costs can be reduced. Furthermore, since the alignment layer in close contact with the liquid crystal is used as a color layer, color display characteristics with good viewing angle dependence without color shift etc. can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of an embodiment of the present invention, FIG. 2A is a cross-sectional side view of a full-color display device according to an embodiment of the present invention, and FIG. 2B is a cross-sectional side view of an embodiment of the present invention. 3 is an exploded perspective view of a general liquid crystal panel, FIG. 4 is a cross-sectional side view of the first example of a conventional liquid crystal color display device, and FIG. 5 is a conventional FIG. 6 is a cross-sectional side view of a second example of a liquid crystal color display device, and FIG. 6 is a cross-sectional side view of a third example of a conventional liquid crystal color display device. ■...Liquid crystal color display device, 2...Liquid crystal, 3...
Transparent substrate, 4... Transparent electrode, 6... Polarizing plate, 15... Orientation layer.

Claims (1)

[Claims] 1. A liquid crystal color display device comprising a liquid crystal (2) and a transparent substrate (3) on which a pair of alignment layers sandwiching the liquid crystal (2) is formed, wherein the pair of alignment layers are , an alignment layer (15) at least one of which contains a colorant in advance.