JPH0368920A - Liquid crystal optical device and driving method thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission-scattering type liquid crystal optical device using a light absorber and a method for driving the same.

[Conventional technology] Twisted nematic (TN), which is well known in the past
BACKGROUND ART Liquid crystal optical elements are used in many fields due to their low power consumption and low cost. However, since this TN mode uses two polarizing films, transmitted light is significantly cut off, resulting in a dark display.

On the other hand, two modes, dynamic scattering (DS) and phase transition (PC), are known for liquid crystal optical elements whose operating principle is light scattering.

Both DS mode and PC mode do not use polarizing plates, so they have the advantage of providing a wide viewing angle, but the former is a current effect type in which a conductive substance is added to the liquid crystal, so it consumes a lot of power. The disadvantage is that the reliability of the system is reduced.

On the other hand, even in the latter case, the operating voltage depends on (interelectrode distance/liquid crystal pitch), so when trying to increase the area, there is a difficult problem that requires a highly accurate and uniform gap. .

In contrast, recently H, G, Craighead et al.
ppl.

Phys, Lett, 40(1) 22 (1982
The method disclosed in ) takes advantage of the characteristic that liquid crystal has refractive index anisotropy, and specifically, impregnates a porous body with liquid crystal, changes the refractive index of the liquid crystal depending on whether or not a voltage is applied, and
Transmission and scattering are controlled by adjusting the refractive index of the porous material.

This method is a useful method because it can theoretically overcome the drawbacks of the DS mode and PC mode without using a polarizing plate. A similar device was published in 1986-50163.
No. 1, JP-A-60-252687, published in 1988-50
No. 2128, etc. Furthermore, it was also announced that it could be used in combination with a light absorber.1986-501345
No. 59-178428, etc.

[Problems to be Solved by the Invention] When colorizing a transmission-scattering type liquid crystal optical device using such a film-like liquid crystal layer, the following has been proposed.

It has also been proposed to change the color of the illumination light as a transmissive type, but it is difficult to change the color locally, and the problem is that it washes out in strong external light and the display becomes invisible. It had In addition, it is known that dichroic dyes are mixed into liquid crystals to change the color, but it is difficult to change the color locally, and liquid crystal optical devices using dichroic dyes are difficult to change. This has the problem that the display often appears blurry.

c Means for Solving Problems] The present invention was made to solve the above-mentioned problems, and includes a film-like liquid crystal layer in which liquid crystal is dispersed and held in a resin matrix between a pair of electrode material substrates. are sandwiched, and when the refractive index of the liquid crystal matches the refractive index of the resin matrix, light is transmitted, and when the refractive index of the liquid crystal does not match the refractive index of the resin matrix, the light is scattered. A liquid crystal optical device characterized in that the refractive index of the resin matrix is selected, a color filter is provided on the front substrate, and a light absorber is provided on the back side of the film-like liquid crystal layer, and the light absorber is colored. A liquid crystal optical device characterized in that a part thereof, particularly a background part, is always in a light transmitting state regardless of the voltage application state, and A liquid crystal optical device characterized in that a film-like liquid crystal layer is used as the film-like liquid crystal layer, which is obtained by curing a mixture of liquid crystal and resin matrix raw materials so that the liquid crystal is dispersed and retained in the resin matrix. and a liquid crystal optical device that uses a liquid crystal optical device that has a portion that is always in a light transmitting state and is driven in such a way that voltage is not applied to the portion that is desired to be displayed, but voltage is applied to the portion that is not desired to be displayed. A driving method is provided.

In the liquid crystal optical device of the present invention, a color filter is provided on the front substrate of the liquid crystal optical element that electrically controls the scattering state and the transmission state, and a light absorber is provided on the back side of the film-like liquid crystal layer. , bright and beautiful color display is possible due to the black color of light absorption and the color of the color filter.

The liquid crystal optical element of the liquid crystal optical device of the present invention has a film-like liquid crystal layer in which liquid crystal is dispersed and held in a resin matrix sandwiched between substrates with counter electrodes, and the scattering state and transmission state are controlled by applying voltage. You can use it as long as it lasts. A color filter is provided on the front substrate of the liquid crystal optical element, and a light absorber is provided on the back side of the film-like liquid crystal layer.

In the present invention, as the film-like liquid crystal layer of the liquid crystal optical element, any material in which liquid crystal is dispersed and held in a resin matrix can be used. Specifically, the liquid crystal may form independent liquid bubbles and be encapsulated in a microcapsule shape, the liquid crystal may be in communication with each other, or the pores of a resin matrix with many fine pores may be formed. It may be filled with liquid crystal.

When such a film-like liquid crystal layer is sandwiched between a pair of electrode-equipped substrates and a voltage is applied between the electrodes, the refractive index of the liquid crystal changes depending on the voltage application state, and the refractive index of the resin matrix changes. The relationship between the refractive index of the liquid crystal and the refractive index of the liquid crystal changes, and when the refractive indexes of the two match, it becomes a transmitting state, and when the refractive indexes differ, it becomes a scattering state.

Specifically, while a voltage is being applied, the refractive index of the cured material constituting the resin matrix is made to match the ordinary refractive index (no) of the liquid crystal.

As a result, when the refractive index of the obtained cured product and the refractive index of the liquid crystal substance match, light is transmitted, and when they do not match, light is scattered (cloudy). The scattering properties of this element are higher than those of conventional DSM (dynamic scattering mode) liquid crystal optical elements, so when a color filter is provided on the front substrate as described later, the back becomes white during scattering. The color of the color filter on the front can be seen, making it easy to obtain a beautiful display.

The film-like liquid crystal layer of the present invention is usually prepared by preparing a mixture of liquid crystal and raw materials for a resin matrix, and then casting the mixture onto an electrode substrate and curing it, or forming a substrate with a pair of electrodes like a normal liquid crystal cell. The liquid crystal may be dispersed and held in the resin matrix by sealing the periphery of the resin matrix with a sealing material, injecting the mixture from the injection port and curing it.

Among these, productivity is improved by using a photocurable resin or thermosetting resin that can be cured in a closed system as a raw material for the resin matrix, and photocuring or thermosetting using a solution of this resin dissolved in liquid crystal. , both the casting and injection manufacturing methods described above are applicable. In particular, it is preferable to use a photocurable resin and photocure.

By making the refractive index of the resin matrix match the refractive index of the liquid crystal (00), when no voltage is applied, a scattering state (i.e. The color filter placed in front of it is visible. Therefore, the color of the color filter is visible in the background part, and only the part to which voltage is applied becomes transparent, and the light is absorbed by the light absorber on the back side, so even if there is a color filter in front of it, it looks black. It turns out.

During the curing process, this element is cured by applying a sufficiently high voltage only to specific parts, or by being heated to a temperature higher than the phase transition point of the liquid crystal. Since it is possible to always make the mark transparent, that is, appear black, if there is information that the company mark normally wants to display, such a normally transparent part may be formed.

If a photocurable resin is used and is cured with a high voltage applied, an electrode is also required for that part, but other parts can be cured at the same time and can be cured in one step. In addition, if the liquid crystal is cured by heating it to a temperature above the phase transition point, the other parts will be cured in a separate process by lowering the temperature, resulting in a two-step process. By providing a film and curing it, you can freely pattern it. For this reason, the latter manufacturing method is used when all areas other than the display area are areas through which light always passes.

When a part through which light passes is provided in this way, the driving method for the liquid crystal optical device is to apply a voltage to the part not to be displayed without applying voltage to the part to be displayed. It can be a method. In particular, this effect is great when all areas other than the display area are areas through which light always passes and the color is the color of the light absorber. That is, when the background part other than the display part is made black by the light absorber, the color of the color filter is visible in the display part when no voltage is applied.

Taking a bar graph display as an example, if it is driven normally in response to an input, the part to which a voltage is applied becomes transparent and appears black, and the entire display becomes black when the input is maximum. This is difficult to see, so if there is no input, the entire screen will be black, and when there is input, it will be displayed in color depending on the size of the input, making it easier to see.

Therefore, it becomes easier to see by not applying voltage to the part you want to display so that the color of the color filter can be seen, and by applying voltage to the part you do not want to display so that it looks black.

In the present invention, a liquid crystal optical element is used in which the refractive index of this resin matrix and the refractive index (no) of the liquid crystal used are matched, and it is preferable to completely match the refractive index, but this does not adversely affect the transmission state. It can be used as long as they match to a certain degree. Specifically, the difference in refractive index is set to 0.
．． It is preferable to keep it at about 15 or less. This is because the resin matrix swells with the liquid crystal, and the refractive index approaches the liquid crystal's refractive index rather than the original refractive index of the resin matrix itself, so even if there is a difference of this degree, almost all light is transmitted. This is because light is absorbed by the light absorber on the back side, making it appear black.

FIG. 1 is a sectional view showing the basic configuration of a liquid crystal optical device of the present invention.

In FIG. 1, 1 is a front substrate made of plastic, glass, etc., and 2 is an ITO (rnaos) formed on its inner surface.
-snow), electrodes such as snow, 3 is plastic,
4 is the IT formed on the inner surface of the substrate on the back side of glass etc.
Electrodes such as O, SnO□, etc., 5 is a color filter formed on the electrode 2 of the front substrate, 6 is a light absorber laminated on the back side of the back substrate 3, and 7 is a seal between the two substrates. A sealing material, 8 a film-like liquid crystal layer sandwiched between substrates, and 9 an observer.

FIG. 2 is a sectional view showing a configuration using a louver of a liquid crystal optical device of the present invention.

In FIG. 2, 11 is a front substrate, 12 is an electrode formed on its inner surface, 13 is a back substrate, 14 is an electrode formed on its inner surface, and 15 is between the electrode 12 of the front substrate and the substrate. 16 is a light absorber formed by a louver placed on the back side of the substrate 13 on the back side; 17 is a color filter formed on the
is a sealing material, 18 is a film-like liquid crystal layer, 19 is an observer,
20 indicates a light source placed on the back side of the light absorber.

In this example, the observer 19 is viewing the liquid crystal optical device from the front. For this reason, the louver blades of the light absorber 16 are tilted about 45'' so that the light from the light source 20 does not directly enter the eyes of the observer 19.

For this electrode, both substrates on both sides may be transparent electrodes, only the electrode on the back side substrate may be a black opaque electrode, or a transparent electrode may be formed on a black light absorber.

When both substrates are made of transparent electrodes, a light absorber is laminated on the back side of the back side substrate. Of course, the substrate itself may be a black substrate. Note that in the above description, the light absorber is black, but it may be of another color such as dark blue. In this case, in the light transmitting state, the color mixture with the light absorber is visible in the area where the color filter is provided, and the color of the light absorber is visible in the area where the color filter is provided. This light absorber may be formed on the entire surface,
It may be formed partially, or light absorbers of multiple colors may be formed. However, a light absorber is formed in a portion where a voltage is applied to change the display.

Specifically, the light absorber can be manufactured by vapor depositing a black material, printing black ink, laminating black sheets or printed materials, or it can be provided on the entire surface, or it can be coated with butter. You may ning.

Further, by using a louver colored black or the like as the light absorber, the degree of freedom in positioning the light source is increased. For example, a light source is placed on the back side, and a louver is used to block direct light from the light source from directly entering the viewer's eyes. By coloring this louver, it can be used as a light absorber. Specifically, if a black-colored louver is used, the light from the light source will enter the liquid crystal optical element obliquely, and the light-scattering portion will appear white and bright, or the color of the color filter, and the light-transmitting portion will appear black. Therefore, it is only necessary to arrange the louver so that the blades of the louver are visible to the observer and the light from the light source does not directly enter the eyes. Thereby, a light source and a light guide plate can also be arranged on the back side facing the viewer.

In the present invention, a color filter is placed on the front substrate. As long as the color filter is on the front side of the substrate, it may be formed on the electrode, between the electrode and the substrate, on the front side of the substrate, or on the substrate itself. may be used as a colored substrate. However, when disposed on the outer surface of the substrate, the color filter is easily noticeable even when the film-like liquid crystal layer is in a transmissive state, so it is preferable to dispose it on the inner surface of the substrate. Various known color filter manufacturing methods such as electrodeposition, printing, photosensitive resist, pasting, vapor deposition, and dyeing methods can be used for the manufacturing method.

This color filter may be formed on the entire surface, may be formed partially, or a color filter of multiple colors may be formed. The less scattering caused by the color filter, the better, and the haze value is 10% or less, preferably 5% or less.

In the present invention, since the color filter is formed on the front substrate, sufficient brightness and color purity can be obtained even in an environment with strong ambient light.

In the liquid crystal optical device of the present invention, on the outside of this liquid crystal optical element,
Ultraviolet cut filters or the like may be laminated, letters, figures, etc. may be printed, or a plurality of liquid crystal optical elements may be used.

Furthermore, in the present invention, when a structure is adopted in which the liquid crystal optical element is exposed to the outside, it is preferable to laminate a protective plate such as a glass plate or a plastic plate on the outside of the liquid crystal optical element. This reduces the risk of damage even if the surface is pressurized, improving safety.

In the present invention, the raw materials for the resin matrix constituting the above-mentioned film-like liquid crystal layer include various resin monomers, oligomers, polymers dissolved in solvents, etc., and are used as a mixture by mixing with the liquid crystal. In this case, it is preferable to use a material in which the raw material of the resin matrix is dissolved in liquid crystal to form a homogeneous solution, but a material in the form of latex may also be used.

When supplying a mixture onto a substrate by casting, it is also possible to use a method that distills off the solvent or generates by-products such as gas during curing, but when injecting liquid crystal into a cell and post-curing it, , use a mixture that can be cured in a closed system without the need for distillation of the solvent and without generating by-products such as gas during curing.

For this reason, it is preferable to use a photocurable resin from the viewpoint of productivity, and it is particularly preferable to use a photocurable vinyl resin.

Specifically, photocurable acrylic resins are exemplified, and those containing acrylic oligomers that are polymerized and cured by light irradiation are particularly preferred.

The liquid crystal used in the present invention includes nematic liquid crystal, smectic liquid crystal, etc., and may be used alone or in a composition. However, in order to meet various required performances such as operating temperature range and operating voltage, a composition may be used. It is more advantageous to use it. In particular, it is preferable to use nematic liquid crystal.

In addition, when a photocurable resin is used for the liquid crystal used in the film-like liquid crystal layer, it is preferable that the photocurable resin is dissolved uniformly, and the cured product after exposure to light does not dissolve or is difficult to dissolve. When using a composition, it is desirable that the solubility of each liquid crystal be as close as possible.

When manufacturing a film-like liquid crystal layer, the resin matrix and liquid crystal may be mixed in a ratio of about 5:95 to 75:25 to form a mixture. It can be used as a concentrate.

When manufacturing a film-like liquid crystal layer, it is possible to form a cell and inject it from an injection port like a conventional ordinary liquid crystal optical element, but it is also possible to supply a mixture of resin matrix raw materials and liquid crystal onto a substrate with electrodes. However, by overlapping the opposing substrates, a liquid crystal optical element can be manufactured with extremely high productivity.

The inter-substrate gap can be operated at 5 to 100 μm, but in the case of a film-like liquid crystal layer, it is appropriate to set it to 7 to 40 μm, taking into account the applied voltage and contrast during on/off. .

In the liquid crystal optical element of the present invention, a dichroic dye, a simple dye, or a pigment may be added to the liquid crystal, or a colored resin matrix may be used.

By using a plastic substrate as the substrate with electrodes, a long liquid crystal optical element using a continuous plastic film can be easily manufactured.

Further, since the liquid crystal optical element of the present invention is generally small in size, there is almost no decrease in productivity even if a cell is formed using a glass substrate and injected in the same way as a normal liquid crystal optical element.

By forming a film-like liquid crystal layer in this way, there is a low risk of short-circuiting between the upper and lower transparent electrodes, and there is no need to strictly control the alignment or the gap between the substrates as in a normal TN type liquid crystal optical element. A liquid crystal optical element whose transmission state and scattering state can be controlled can be manufactured with extremely high productivity.

When the substrate is made of plastic or thin glass, this liquid crystal optical element can be further protected by laminating a protective plate of plastic or glass on the outside, or by using tempered glass, laminated glass, wired glass, etc. Various applications such as good are preferred.

The liquid crystal optical element of the present invention is used with additional driving means. As described later, this driving means usually uses several tens of V.
It is only necessary to use a device that can apply an alternating current voltage of approximately Although the electrode pattern may be a solid electrode over the entire surface, it is preferable to use a desired pattern of electrodes so that the desired pattern is displayed in color when a voltage is applied.

In this case, two or more color filters may be used for one pattern to display a plurality of colors, or two or more color filters may be used for each pattern to display a plurality of colors.

Furthermore, when curing the liquid crystal optical element, the negative part may be displayed as a fixed display, that is, always in a state where light is transmitted, or always in a state where light is scattered.

Specifically, we use a mixture of liquid crystal and photocurable resin in which the ordinary refractive index (no) of the liquid crystal matches the refractive index of the resin matrix, and when curing it by irradiation with light, the specific By applying a voltage to only the portion and curing it, or by heating it to a temperature higher than the phase transition temperature and curing it, the specific portion becomes an ordinary light transmitting portion. Therefore, when no voltage is applied, that specific part becomes a transparent state, and the light absorber gives that specific color, for example, black, and the other parts are in a scattering state, so you can see the color of the color filter. .

Then, when a voltage is applied to a desired portion, that portion also becomes light-transmissive, and the light absorber causes it to take on that specific color, for example, black.

Fixed display areas like this can be hidden by using a light-blocking mask.
It may be formed by repeated exposure, or it may be patterned by irradiation with a laser or the like. Furthermore, the light absorber of the present invention may be partially provided and this light absorber may be used as a light-shielding mask during light exposure.

By always keeping the parts other than the display part in a light-transmitting state, color display can be performed using color filters on a black background without providing a light-shielding film. In particular, in a typical TN type liquid crystal optical device, unless light is blocked by a light-shielding film within the cell, the appearance will deteriorate due to parallax when viewed from an oblique direction. However, in the liquid crystal optical device of the present invention, the film-like liquid crystal layer is fixed by curing using a light-shielding mask. This is the same as if it were provided, and there is less deterioration in appearance due to parallax.

When applying a voltage for driving the liquid crystal optical device of the present invention, it is sufficient to apply an alternating current voltage that changes the alignment of the liquid crystal. Specifically, at 5 to 100V, lO to 1000
) Approximately 1 part AC voltage may be applied.

In the liquid crystal optical device of the present invention, an active element such as a TPT is formed in each pixel, and a dot matrix display or a television display can be performed using an RGBS or monochromatic color filter.

[Function] According to the present invention, a color filter is provided on the front substrate of a film-like liquid crystal layer in which liquid crystal is dispersed and held in a resin matrix, and a light absorber is provided on the back side substrate corresponding to the back side of the film-like liquid crystal layer. ing.

Therefore, when the refractive index of the liquid crystal matches the refractive index of the resin matrix, light is transmitted, absorbed by the light absorber on the back side, and the color of the light absorber, such as black, is visible. Conversely, when the refractive index of the liquid crystal does not match the refractive index of the resin matrix, light is scattered and the color of the color filter on the front side is visible.

Since the liquid crystal optical device of the present invention utilizes such a principle, a bright display of the color of the light absorber such as black and a unique color can be obtained. For example, a black display on a red background can be obtained. In particular, since the present invention uses phase change, there is no need to use a polarizing film, and the colors of the color filters are not dark (not visible) like in conventional TN type liquid crystal display devices, but appear brighter.

Furthermore, since it is a reflective type, the display will not become invisible even when exposed to strong external light such as direct sunlight.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 A black light absorbing plate manufactured by Tsutsunaka Plastics Co., Ltd. was attached and laminated on the back side of a glass substrate with ITO patterned with a bar graph to produce a back side substrate.

A resist type color filter manufactured by Fuji Hunt Co., Ltd. is placed on the ITO of the glass substrate, which is patterned with ITO so as to face the patterned ITO of the back side substrate, with a thickness of 2.
μm was formed and manufactured as a front substrate.

The back side substrate and the front side substrate were sealed at their peripheries with a 20 μm spacer interposed therebetween to form a cell.

7 parts of 2-ethylhexyl acrylate and 15 parts of 2-hydroxyethyl acrylate, 24 parts of acrylic oligomer (rM-1200J manufactured by Toagosei Kagaku Co., Ltd.), and 0.9 parts of "Procure 1116J" manufactured by Merck & Co. as a photocuring initiator. A liquid crystal mixture was prepared by uniformly dissolving 1 part and 64 parts of rE-8J manufactured by BDH Co., Ltd. as a liquid crystal.

This liquid crystal mixture was injected into the cell described above and exposed to ultraviolet rays for 30 seconds to produce a liquid crystal optical device. In this liquid crystal optical device, the refractive index of the cured material constituting the resin matrix is the ordinary refractive index of the liquid crystal (no.
), so when no voltage is applied, the refractive index of the two is different, the whole becomes scattered (cloudy), and the color of the color filter can be seen. Note that the portion where the color filter was not formed appeared white.

This liquid crystal optical device is rotated at a 45° angle to prevent regular reflection of light.
When viewed from the front while tilted, the bar graph area appeared to be the color of the color filter, and the rest of the background appeared to be white. When an alternating current voltage (AC 30 V, 50 Hz) was applied to this, only the bar graph portion to which the voltage was applied became transparent, and a black color was visible.

Therefore, an easy-to-read display was obtained by driving the bar graph by performing reverse driving in which voltage was applied only to segments that were not desired to be displayed.

Example 2 ITO with patterned frame around bar graph and its surroundings
The glass substrate with attached was used as the back substrate.

A resist-type color filter manufactured by Fuji Hunt was placed on the ITO of the glass substrate, which was patterned with ITO, so as to face the patterned ITO of the back side substrate.
It was formed to have a thickness of 2 μm and was manufactured as a front substrate.

The back side substrate and the front side substrate were sealed at their peripheries with a 20 μm spacer interposed therebetween to form a cell.

A mask having openings only in the frame around the bar graph was placed, and exposure was performed by irradiating ultraviolet rays for 30 seconds while applying an alternating current voltage (AClooV, 50 Hz). Then,
The mask was removed, and the entire structure was exposed to ultraviolet light for 30 seconds without applying any voltage to complete curing of the resin in the liquid crystal mixture.

Thereafter, a black light absorbing plate manufactured by Tsutsunaka Plastic Co., Ltd. was attached to the back side of the back side substrate to manufacture a liquid crystal optical device.

This liquid crystal optical device is rotated at a 45° angle to prevent regular reflection of light.
When viewed from the front while tilted, the black frame and bar graph part appeared to be the color of the color filter, and the rest of the background appeared to be white. This is AC voltage (AC30V, 50V)
When H2) was applied, the bar graph area and the frame to which the voltage was applied became transparent, and black color was visible.

Example 3 A liquid crystal optical device was manufactured in the same manner as in Example 1 except that the color filter of Example 1 was formed on the entire surface of the front substrate.

This liquid crystal optical device was the same as Example 1, except that the color of the color filter was visible in all parts where the film-like liquid crystal layer was in a light scattering state.

Example 4 The light absorber in Example 1 was replaced with a louver with black blades, a light source was placed on the back side of the louver, and the louver blades were rotated at a 45° angle.
The camera was tilted so that the viewer looked straight ahead, and the light from the light source did not directly enter the viewer's eyes.

In this example, the light source was provided at a position facing the observer, but the light from the light source did not directly enter the observer's eyes, and the appearance was the same as in Example 1.

Example 5 The liquid crystal optical device of Example 4 was exposed to ultraviolet rays for 30 seconds at a temperature higher than the phase transition temperature of the liquid crystal by placing a mask corresponding to the bar graph display section. Then, the temperature was lowered to room temperature, the mask was removed, and the entire structure was exposed to ultraviolet light for 30 seconds to complete curing of the resin in the liquid crystal mixture.

In this liquid crystal optical device, the bar graph part looked like the color of the color filter, and the rest of the background looked black. to this,
When an alternating current voltage (AC30V, 50H2) was applied, only the bar graph portion to which the voltage was applied became transparent, and black color was visible.

Therefore, by driving the bar graph in the opposite manner by applying voltage only to the segments that you do not want to display, you can obtain an easy-to-read display in which the color of the color filter is displayed on a black background. Ta.

[Effects of the Invention] As described above, according to the present invention, a film-like liquid crystal layer in which liquid crystal is dispersed and held in a resin matrix is used, a color filter is provided on the front substrate, and a light absorber is provided on the back substrate. Because of this, when the refractive index of the liquid crystal matches the refractive index of the resin matrix, light is transmitted and the color of the light absorber, such as black, on the back side can be seen. Conversely, when the refractive index of the liquid crystal does not match the refractive index of the resin matrix, light is scattered, so
You can see the color of the color filter on the front side.

Since the liquid crystal optical device of the present invention utilizes such a principle, a bright display of the color of the light absorber, such as black, and the unique color of the color filter can be obtained. For example, a black display on a red background can be obtained. Furthermore, unless a color filter is provided in the background area to which no voltage is applied, a display of red and black on a white background, etc. can be obtained. In particular, since the present invention uses phase change, there is no need to use a polarizing film, and the conventional T
Unlike N-type liquid crystal display devices, the colors of the color filters are less likely to appear dark and dull, and appear brighter.

In addition, if a color filter is not provided in the background area to which no voltage is applied, the white area will not become dark gray, green or reddish like in conventional TN type liquid crystal display devices, and the white area will become whiter and brighter. appear.

In addition, even without using a light-shielding film inside or outside the cell, a desired area can be colored black or the like by combining a light absorber and a light transmitting part, increasing light utilization efficiency and further increasing display brightness. I can do it.

In addition to this, the present invention can be applied in various other ways as long as the effects of the present invention are not impaired.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the basic configuration of a liquid crystal optical device of the present invention. FIG. 2 is a sectional view showing a configuration using a looper of a liquid crystal optical device according to the present invention. Substrate = 1.3.11.13 electrode
: 2.4.12.14 Color filter: 5.
15 Light absorber: 6.16 Sealing material: 7.17 Film liquid crystal layer: 8.18 Observer: 9.19 Light source = 20

Claims (6)

[Claims] (1) A film-like liquid crystal layer in which liquid crystal is dispersed and held in a resin matrix is sandwiched between a pair of electrode-equipped substrates, and when the refractive index of the liquid crystal matches the refractive index of the resin matrix, light is transmitted; The refractive index of the liquid crystal and the refractive index of the resin matrix are selected so that when the refractive index of the liquid crystal does not match that of the resin matrix, the refractive index of the liquid crystal and the refractive index of the resin matrix are selected. A liquid crystal optical device characterized by having a light absorber on the back side. (2) A liquid crystal optical device according to claim 1, wherein a colored louver is used as the light absorber. (3) A liquid crystal optical device according to claim 1 or 2, characterized in that a part of the device is always in a light transmitting state regardless of the voltage application state. (4) The liquid crystal optical device according to claim 3, wherein the background portion is always in a light transmitting state. (5) As the film-like liquid crystal layer according to claim 1, 2, or 3, a film-like liquid crystal layer is used, which is obtained by curing a mixture of liquid crystal and raw materials for the resin matrix so that the liquid crystal is dispersed and held in the resin matrix. A liquid crystal optical device characterized by: (6) A method for driving a liquid crystal optical device, using the liquid crystal optical device according to claim 3 or 4, in which a voltage is not applied to a portion desired to be displayed, but a voltage is applied to a portion not desired to be displayed.