JPH02176630A - Ferroelectric liquid crystal color light source - Google Patents

Abstract

PURPOSE:To reduce the power consumption and to reproduce intermediate colors tone of color filters by one light source by providing a ferroelectric liquid crystal cell which colors the light from a light source in red, green, and blue. CONSTITUTION:The ferroelectric liquid crystal cell 20 is constituted by sticking a substrate 11 obtained by forming a transparent electrode 16 on soda glass 15 and a substrate 12 obtained by forming transparent electrodes 16 and a liquid crystal orienting film 17 on soda glass 15 and then injecting ferroelectric liquid crystal 14 between the substrates, and color filters 13 are formed outside the substrate 12. Here, the transparent electrode 16 on the substrate 11 is not patterned and an entire-surface electrode and the transparent electrode 16 on the substrate 12 are formed in stripes; and polarizing plates 72 and 73 are arranged outside the substrates 11 and 12. Then the color of the light emitted by a light source 40 is changed into red, green, and blue over the entire surface of the ferroelectric liquid crystal cell 20 by utilizing the scattering of the light. Consequently, the power consumption is reduced and intermediate color toners of the color filters are obtained by the one light source 40.

Description

[Detailed Description of the Invention] (Prior Art) Conventional color light sources include a structure in which a white fluorescent lamp or an incandescent lamp is equipped with a color filter, or a structure in which a gas such as neon is sealed in the lamp. It has been used as a light source with various colors. however,
With these methods, only one type of color can be emitted from one fluorescent lamp or light bulb, and many light sources are required to emit light of many types of colors.

In addition, in order to emit light of many types of colors with one light source, by rotating many types of color filters around one light source, it is possible to emit light of many types of colors in any direction. However, in this method, there is a limit to the rotation speed of the filter, so when the light source is white, only the color of the filter is emitted.

Furthermore, since a large amount of power is consumed to rotate the filter, there has been a desire for lower power consumption.

[Structure of the invention]

In order to solve the above problems, the present invention is characterized by having a ferroelectric liquid crystal cell for converting the light from the light source into red, green, and blue colors, respectively.

The structure of the ferroelectric liquid crystal cell is that a ferroelectric liquid crystal is interposed between a pair of transparent substrates having transparent electrodes, and R, G, B
The structure has a color filter outside the cell.

In the present invention, "Cell J" refers to a structure in which a pair of substrates are bonded together with a small space between them, and the space is filled with liquid crystal.

In the present invention, a liquid crystal alignment means may be provided on the surface of the substrate of the ferroelectric liquid crystal cell that is in contact with the liquid crystal.

Further, the color filter only needs to be formed on the outside of at least one substrate of the ferroelectric liquid crystal cell, and it does not matter whether it is on the light source side or on the opposite side. The substrate on which the color filter is formed is preferably as thin as possible so that the color filter is located close to the liquid crystal.

The transparent electrodes of the ferroelectric liquid crystal cell according to the present invention may be formed in a matrix shape, but one electrode may be striped and the other may be unpatterned, that is, one electrode may be formed on one surface. Furthermore, in this case, it is easier to manufacture the striped electrodes if the width thereof is widened.

Further, the shape of the color filter may be the same as that of the electrode formed in a stripe shape. The color filter may be formed using a commonly used photolithography method or a printing method.

In the present invention, two polarizing means are used on both sides of the ferroelectric liquid crystal cell.

Zero generation uses light scattering to change the color of light emitted from a light source (eg, white) to red, green, and blue across the entire surface of a ferroelectric liquid crystal cell. Therefore, it is desirable to thicken the front side (the side opposite to the light source) of the substrate used in the ferroelectric liquid crystal cell.

A method of changing the color of the light source to each of red, green, and blue in the present invention will be explained with reference to FIG.

In FIG. 1, tR, t6, and LBs indicate timing charts for signals applied to the electrodes of the portions of the ferroelectric liquid crystal cell where the red, green, and blue color filters are present, respectively. Note that the horizontal axis indicates time.

As shown in the figure, at A-B, the light of the red filter of the ferroelectric liquid crystal cell is transmitted, and then at B-C.
This allows light to pass through the part of the ferroelectric liquid crystal cell where the green filter exists. Then, at CD, light from the portion of the ferroelectric liquid crystal cell where the blue filter exists is transmitted, and blue light is emitted. In this way, the emission of one color as a color light source ends at A-D.

As explained above, the device of the present invention emits one color as a color light source by emitting red, green, and blue light three times, so it is possible to emit only three different colors of light. However, since it uses a ferroelectric liquid crystal with a fast response speed,
By emitting red → green → blue at high speed, it appears to the human eye that the radiation is occurring simultaneously, and red, green, etc. such as purple, etc.
The pre-removal color can also be emitted. For example, purple only needs to emit both red and blue. However, conventional TN liquid crystals cannot be used in the present invention because of their slow response speed.

By using the present invention, it is not necessary to use a plurality of color filters to emit a plurality of colors as in the past, and power consumption can be reduced. Furthermore, a single light source can produce intermediate color tones of color filters.

Examples of the present invention will be described below.

[Example 1] FIG. 2 shows an example of a schematic cross section of a ferroelectric liquid crystal cell that is a part of the structure of the present invention. FIG. 3 shows a schematic cross-section of a ferroelectric liquid crystal color light source constructed according to the present invention.
Give an example. Furthermore, FIG. 4 shows a perspective view of a portion of the ferroelectric liquid crystal cell.

In the ferroelectric liquid crystal cell 20, the transparent electrode 16 is made of soda glass 1.
A substrate 11 formed on a glass substrate 5 and a substrate 12 formed on a soda glass 15 with a transparent electrode 16 and a liquid crystal alignment film 17 were bonded together, and a ferroelectric liquid crystal 14 was injected between the substrates. A color filter 13 was then formed on the outside of the substrate 12. Here, the transparent electrode was formed on the entire surface of the substrate 11 side without patterning, and on the substrate 12 side, it was formed in a striped structure.

Furthermore, polarizing plates 72 and 73 are placed on the outside of the substrate 11 and on the outside of the substrate 12.
Place it outside of.

In this structure, the polarizing plate 73 placed below the ferroelectric liquid crystal cell may be placed directly on the light source 40.

When using the configuration shown in FIG. 3, which is an example of the present invention, light emitted from a white light source (fluorescent lamp) 40 passes through one polarizing plate 73 to become linearly polarized light, and then passes through a color filter 13. Displays the color of each filter. When displaying red, turn off the liquid crystal above the green and blue filters.
state, and the polarizing plate 72 absorbs light. Then, only the liquid crystal present in the second part of the red filter is turned on, and the light passes through the polarizing plate between the two cells. At this time, light is diffused by the upper substrate 11 of the ferroelectric liquid crystal cell, and the entire ferroelectric liquid crystal cell emits red color. After that, radiation is performed for green and blue in the same way.

Because the speed of radiation is so fast, it appears to the human eye that writing is being done simultaneously. In this example, writing was performed in 10 μs for each of red, green, and blue, so
It looked like they radiated at exactly the same time.

[Example 2] A ferroelectric liquid crystal color light source manufactured with exactly the same configuration as in Example 1 was used as a backlight for a cell using ferroelectric liquid crystal. A simple cross-sectional view in this case is shown in FIG. Here, the polarizing plate (7
1, 72, 73) used three sheets.

In FIG. 5, the light emitted from the white light source 40 passes through one polarizing plate 73 and becomes linearly polarized light, and the color filter 13
The light passes through the filter and takes on the color of each filter. When displaying red, the liquid crystals located above the green and blue filters are turned off, and the polarizing plate 72 located between the display cell 10 and the ferroelectric liquid crystal cell 20, which is part of the structure of the present invention, is turned off. absorbs light.

At the same time, only the liquid crystal present above the red filter is turned on, and the liquid crystal passes through the polarizing plate between the two cells. At this time, the light is diffused by the substrate 11 above the cell 20, and the cell 20
The entire 0 emits red. Then, only the pixels that require red in the display cell 10 synchronized with the cell 20 are turned on, and the unnecessary pixels are turned off. And Off
The light that has passed through the pixel that has been turned on is absorbed by the polarizing plate 71 on the upper side of the display cell 10, and the polarization state of the light that has passed through the pixel that has been turned on is changed by the ferroelectric liquid crystal of the display cell 10. It passes through the polarizing plate 71 above the display cell 10. The trailing edge, blue, is also displayed in the same way.

In this embodiment, by providing the space 50 between the display cell 10 and the cell 20, in addition to the light diffusion by the substrate 11, the light spreads in the space 50, making the color more uniform throughout the display cell 10. obtained.

〔effect〕

As explained above, by using the configuration of the present invention, power consumption can be reduced, and a single light source can also produce a color tone intermediate to that of a commonly used color filter.

[Brief explanation of the drawing]

FIG. 1 shows a timing chart of a ferroelectric liquid crystal cell that is part of the structure of the present invention. FIG. 2 shows an example of a schematic cross-section of a ferroelectric liquid crystal cell that is part of the structure of the present invention. FIG. 3 shows an example of a schematic cross-section of a ferroelectric liquid crystal color light source having the structure of the present invention. FIG. 4 shows an example of a perspective view of a ferroelectric liquid crystal cell that is part of the structure of the present invention. FIG. 5 shows a schematic cross-section of one application of the invention. 1.15... Soda glass 2.16... Transparent electrode 3.17... Liquid crystal alignment film 4.14... Ferroelectric liquid crystal 5.6 .11.12...Substrate 10...Display cell 13...Color filter 20...Light source cell 40...Light source (firefly) Light lamp) 50... Space 71.72.73... Polarizing plate

Claims (1)

[Claims] 1. A light source; a cell in which a ferroelectric liquid crystal is interposed between a pair of substrates having transparent electrodes, and a color filter on the outside of the substrate; a polarizing means for identifying a plurality of states of the ferroelectric liquid crystal; A ferroelectric liquid crystal color light source characterized by having;