JPS63148235A - Liquid crystal shutter array - Google Patents

Abstract

PURPOSE:To record a color image without using any color filter by providing three arrays of liquid crystal layers which are thin enough to transmit light beams of three colors R, G, and B and arranging light shield materials among and outside the liquid crystal layers. CONSTITUTION:Common electrodes 21B, 21G, and 21R are arranged on the reverse surfaces of liquid crystal materials 20B, 20G, and 20R, a light-input side substrate 30 is arranged on the liquid crystal materials 20B, 20G, and 20R, and pixel electrodes which prescribe R, G, and B picture element arrays linearly are arranged in a constant shape at constant intervals. Glass substrates 22R, 22G, and 22B made of transparent materials are arranged below the common electrodes 21R, 21G, and 21B; and light shield materials 26 and 27 are arranged among the R, G, and B picture element arrays and light shield materials 26 and 27 are arranged outside them to prevent light from being entered directly and by straying. Further, a polarizing plate 28 is provided as the lowermost layer of a light-output side substrate 20. Consequently, spectral transmissivity characteristics of B, G, and R are obtained without using a color filter nor a color light source, and a color image is easily recorded with white light.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a structure of a liquid crystal shutter array that is capable of recording color images with spectral transmittance characteristics depending on the thickness of a liquid crystal layer.

(Technical Background of the Invention and Problems Thereof) Conventionally, when recording a color image on a photosensitive material using a liquid crystal shutter array, a configuration as shown in FIG. 5 was generally used. That is, light emitted from a white light source 1 is converted into parallel light by an optical system 2 comprising a condenser lens, and the parallel light is emitted onto, for example, a liquid crystal shutter array 3 having a line structure. And this liquid crystal shutter array 3
The area between the pixel electrode and the common electrode is optically controlled on and off in response to an image signal from a control device (not shown), etc., and the photosensitive material 5 is exposed to light in units of pixels. , three color filters 4R of R (red), G (green) and B (blue) are provided between the liquid crystal shutter array 3 and the photosensitive material 5.
.

A color filter 4 having 4G and 4B is arranged, and RG
Image light is sequentially recorded on the photosensitive material 5 by filters 4R, 4G, and 4B corresponding to the B color. In this case, the color filter 4 is IIG[l's filter 4R, 4
After one line of image is recorded by mechanically switching between G and 4B, conveyance control is performed on the photosensitive material 5 to record the next line, and such recording is performed one line at a time. Thus, the entire color image is recorded on the photosensitive material 5.

In this way, in the conventional liquid crystal shutter array 3, when recording a color image, the color filter 4 is used to convert RGB
shall be recorded in order according to the resolved light. This has resulted in disadvantages in that the recording apparatus has become larger and the control of the color filters has become more complicated. Furthermore, since a color filter is used, the color transmission efficiency is poor, and there is also the drawback that color turbidity occurs in the recorded image.

(Object of the invention) This invention was made under the above circumstances,
The purpose of this invention is to set the thickness of the liquid crystal layer for each of the three IIGB colors based on the spectral transmittance characteristics with respect to the thickness of the liquid crystal layer, and to use the transmitted light of 868 colors of the set RGB three-color liquid crystal to An object of the present invention is to provide a liquid crystal shutter array capable of recording color images without using color filters.

(Summary of the Invention) This invention relates to a liquid crystal shutter array for recording color images, and based on the spectral transmittance characteristics with respect to the thickness of the liquid crystal layer, the Rows of liquid crystal layers are provided, and a light shielding material is provided between and along the outside of the liquid crystal layers.

(Embodiment of the invention) By the way, the light transmittance of a ferroelectric liquid crystal is determined by changing the thickness of the liquid crystal to d.
, (r!i crystal refraction When the refractive index orientation is Δn, for the wavelength, I −T, (5in(4θ) ・5in(
yrd Δmouth/λ))2・・・・・・・・・(1) Therefore, the spectral transmittance characteristic Tr for the product of the thickness d of the liquid crystal layer and the anisotropy Δn is Regarding color, a curve like that shown in Fig. 1 is obtained.

That is, the blue color B has a wavelength λ=450 nm, and by substituting this value into the above equation (1), a characteristic as shown by the dashed-dotted line B is obtained. Similarly, green G has wavelength λ = 550 nm
By substituting this into equation (1), a broken line characteristic G is obtained, and red color R has a wavelength λ=650 nm, and by substituting this into equation (1) above, a solid line characteristic R is obtained.

As is clear from the characteristic diagram in Figure 1, d×Δn is 0
．． In the vicinity of 6, the transmittance of blue B is as high as approximately 100*, and the transmittances of green G and red R are approximately O, and only B light is transmitted here. Also, d×Δn is 1
．． In the vicinity of 32, the spectral transmittance characteristics of green G are close to 100%, while the spectral transmittance characteristics of blue B and red R are almost 0.
Therefore, it can be seen that only the G light passes through the liquid crystal. Furthermore, when d×Δn is around 2.22, the spectral transmittance characteristics of red R are almost 100%, while the spectral transmittance characteristics of blue B and green G are almost O, so here R It can be seen that only light passes through the liquid crystal.

In this invention, the thickness d (or d×
Using the spectral transmittance characteristic Tr for [iGI'], as shown in FIGS.
Liquid crystal shutter array with different thicknesses DB, DG, and DR of the liquid crystal layer for 0G and 20R! It constitutes 0. That is, within the light output side substrate 20 there are liquid crystals 208 having different layer thicknesses.
．． 20G and 2OR are arranged in a line to form parallel three-color pixel rows, and these liquid crystal 208.20G
, 2OR have common electrodes 21B, 21G, 21 on the lower surface of each
A light input side substrate 30 is provided above each of the liquid crystals 208, 20G and 2OR, and pixel electrodes 31 defining each RGB pixel column in a line shape are arranged as shown in FIG. They are arranged at intervals of one shape. Common electrode 21R,
Below each of 21G and 21B is a transparent glass substrate 22R.
, 22G, and 22B are arranged, and light shielding materials 23 and 24 are arranged between the IIGB pixel rows, and light shielding materials 26 and 27 are also arranged on the outside to prevent light from entering or going around. It is supposed to be done. Furthermore, a polarizing plate 28 is provided at the bottom layer of the light output side substrate 20.

On the other hand, the light input side substrate 30 is configured by layering a transparent glass substrate 33 and a polarizing plate 34, and includes a liquid crystal 2011.
．． Pixel electrodes 31 are provided in positions corresponding to 20G and 20B as shown in FIG. A light-shielding photomask 32 is provided on the light input side substrate 30 in a positional relationship and size corresponding to that of the pixel electrode 31, as shown by the shaded area in FIG. In this case, liquid crystal 20B for each BGH.

The thicknesses DB, DG, DI+ of the liquid crystal layer of 20G and 20R are
The spectral transmittance characteristic d×Δn shown in Figure 1 is 0.6.1
．． By enclosing them in a relationship of 32°2.22, when irradiated with white light, only the B light is transmitted through the liquid crystal 20B, only the G light is transmitted through the liquid crystal 20G, and only the R light is transmitted through the liquid crystal 20R. Therefore, even when the light source irradiating the liquid crystal shutter array lO is white light, light separated into the three colors of BGH can be output from the liquid crystal shutter array 10, and according to the liquid crystals 20B, 20G, and 20R of each BGH. By controlling the pixel electrode 31 using the BGH, it becomes possible to record pixels for each BGH. This makes it possible to record color images.

In the above embodiment, the liquid crystal shutter array is filled with liquid crystals of three BGR colors.
It is also possible to provide a color or a combination of two colors. Furthermore, although the above-mentioned embodiment uses a strongly galvanic liquid crystal, D
This is possible even in systems using non-twisted nemadeic liquid crystals, such as the AP method and the ECB method, by adjusting the setting of dΔn.

(Effects of the Invention) As described above, according to the liquid crystal shutter array of the present invention, BGII can be used without using color filters or color light sources.
It is possible to obtain a spectral transmittance characteristic of , and it becomes possible to easily record a color image using white light. Furthermore, since no optical system such as a filter is used, the apparatus can be made smaller and it is possible to record sharp images with less color turbidity.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram for explaining the invention in detail, Figure 2 is a characteristic diagram for explaining the invention in detail.
3 is a perspective structural diagram of a transparent substrate 13 thereof, and FIG. 4 is a structural diagram of a light input side substrate of a liquid crystal shutter array of this invention. FIG. 5 is a diagram for explaining how a color image is recorded by a conventional liquid crystal shutter array. DESCRIPTION OF SYMBOLS 1... Light source, 2... Optical system, 3-... Liquid crystal shutter array, 4... Color filter, 5... Photosensitive material, 10... Liquid crystal shutter array, 31... Vixel electrode , 20B, 20G, 20R...LCD, 21B,
21G, 21R... Common electrode, 22R, 22G, 2
2B...Glass substrate, 23-27...Light shielding material, 28
．． 34...Polarizing plate, 33...Transparent substrate. Applicant's agent Yu Yasugata Sanna 2nd ward sheep 3rd eye

Claims (1)

[Claims] Based on the spectral transmittance characteristics with respect to the thickness of the liquid crystal layer, RG
A liquid crystal shutter array characterized in that three rows of liquid crystal layers are provided with a thickness that allows each of three B colors to pass through, and a light shielding material is provided between and along the outside of the liquid crystal layers.