JPH0496047A - Liquid crystal exposing device - Google Patents

Abstract

PURPOSE:To eliminate the need of a filter and an expensive light source, to simplify a device, to reduce the producing cost, and further to shorten an exposing time by means of the simultaneous linear exposures of three primary colors by selecting three primary colors excellent in wavelength properties through the use of an optical prism. CONSTITUTION:Light from a halogen lamp 3 becomes parallel light by a condenser lens 4, and is made incident on an LCD shutter 5 controlled by a controller 9 based on an image signal inputted from the outside. Three lights 11, 12, and 13, transmitting respective element lines 5R, 5G, and 5B and separated by a slit 6, are dispersed to produce spectra when they are emitted from a prism 7. Only lights 11R, 12G, and 13B having respective wavelength properties are selected out of the spectra by a slit 8 and a linear exposure can be, simultaneously, carried out on a microcupsule sheet 20.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid crystal exposure device used in an image recording device for color printing out color images and character data based on video signals, etc. The present invention relates to a liquid crystal exposure device that can select three primary colors with excellent wavelength characteristics using an optical prism.

[Conventional technology]

In recent years, various liquid crystal display elements (LCDs) have been developed that utilize various electro-optic effects in liquid crystals to switch between light transmission and light blocking.
) The shutter has been developed.

Here, among the LCD shutters, a twisted nematic (TN) type LCD shutter will be explained. This TN type LCD shutter is made up of a plurality of liquid crystal light modulation elements arranged, and in each liquid crystal light modulation element, the liquid crystal is formed by two transparent electrode substrates (outside) and two sheets having uniform linear grooves. It is sandwiched between the alignment film (inner side). When no voltage is applied between the transparent electrodes, the liquid crystal molecules assume a specific alignment state according to the force regulated by the grooves of the alignment films, but the groove directions of the two alignment films are mutually Since they are shifted by 90 degrees, the liquid crystal molecules exhibit a twisted structure in the long axis direction of the molecules, and the alignment of the liquid crystal molecules is twisted by 90 degrees between both alignment films. When the TN type liquid crystal light modulation element in this state is sandwiched between two polarizing plates whose polarization directions are perpendicular to each other, and a light beam is incident from one of the polarizing plates, the light beam becomes linearly polarized light at the first polarizing plate. While this linearly polarized light travels through the liquid crystal, the polarization direction of the linearly polarized light is rotated by 90 degrees due to the birefringence of the liquid crystal molecules and the above-described 90 degree twisted alignment structure. As a result, the polarization direction of the linearly polarized light matches the polarization direction of the other polarizing plates, and the linearly polarized light is emitted as is. However, when a voltage is applied between the transparent electrodes, the liquid crystal molecules are forcibly aligned in the direction of the electric field, so that the above-mentioned 90 degree twisted alignment structure of the liquid crystal molecules is not formed.

Therefore, the linearly polarized light incident from one polarizing plate reaches the other polarizing plate without rotation of the polarization direction, and when it is output, the polarization direction of the linearly polarized light and the polarization direction of the other polarizing plate are orthogonal and the light is blocked. be done.

In this way, switching between light transmission and light blocking is performed by applying a voltage between the transparent electrodes, making it possible to provide a shutter with a high response speed.

Focusing on the characteristics of such LCD shutters, we
A liquid crystal exposure device using a shutter has been developed. Conventional liquid crystal exposure equipment uses red (R), green (G), and blue (
In order to expose each of the three primary colors of B), the light from the light source is
, B, or a special light source such as a metal halide lamp that has wavelength characteristics only for R, G, and B.

[Problem to be solved by the invention]

However, when using three types of filters, R, G, and B, a filter control system and drive system are required, which makes the device complicated, and special light sources such as metal halide lamps are expensive. Therefore, there is a problem in that the manufacturing cost of the device increases.

The present invention has been made in view of the above-mentioned circumstances, and provides a liquid crystal display that can select three primary colors with excellent wavelength characteristics without using filters or special light sources, and can reduce manufacturing costs. The purpose is to provide an exposure device.

[Means to solve the problem]

In order to achieve such an object, the present invention provides a liquid crystal exposure apparatus that exposes a photosensitive recording medium based on an image signal. a condenser for condensing light from the light source onto the LCD shutter; a controller for controlling the LCD shutter according to an image signal; a prism; and a predetermined wavelength of the dispersed light transmitted through the prism. The structure includes a slit for irradiating the light onto the photosensitive recording medium.

[Effect]

The light emitted from the light source is collected by a condensing means and converted into an LC.
The light that enters the D shutter and passes through the LCD shutter, which is controlled by the controller according to the image signal, passes through the prism and becomes dispersed light that takes an optical path depending on the wavelength, and is dispersed between the prism and the photosensitive recording medium. Only the light selected by the slit located at is irradiated onto the photosensitive recording medium to perform exposure. Thereby, three primary colors with excellent wavelength characteristics can be selected without using a filter or a special light source.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

First, an example of an image recording apparatus using the liquid crystal exposure apparatus of the present invention will be described. FIG. 1 is a schematic diagram of an image recording apparatus using a liquid crystal exposure apparatus of the present invention. In FIG. 1, an image recording device 1 includes a liquid crystal exposure device 2, and is configured such that a long microcapsule paper 20 as a photosensitive recording medium is conveyed through an exposure area 15 below the liquid crystal exposure device 2. There is.

The microcapsule paper 20 has a plurality of microcapsules coated on the surface of a long support, and the microcapsules contain a dye precursor that reacts with a color developer described later. And unexposed microcapsule paper 20
is mounted in a light-shielding cartridge holder 21 while being wound around a cartridge ν axis 22. Further, on the right side of this cartridge 21, feed rollers 23, 23 for conveying the microcapsule paper 20 are arranged.

The microcapsule paper 20 that has passed through the exposure area 15 below the liquid crystal exposure device 2 and has been exposed to light is pressed by the pressure rollers 30a and 30b while being overlapped with the color developer paper 35, and is subjected to pressure development.

After that, the microcapsule paper 2 separated from the color developer paper 35
0 is wound around a cartridge shaft 27 disposed within the cartridge 26.

A cassette 37 in which a plurality of color developing papers 35 are stacked and stored is installed above the pressure rollers 30a, 30-t. A half-moon roller 41 is disposed on the upper left side of the skein/soto 37, and this half-moon roller 41
The developer paper 35 is fed one by one by the rotation of the
Sent to 2 rooms. The fed-out color developer paper 35 is conveyed to pressure rollers 30a and 30b via a feed guide 43 at a timing such that the leading edge of the color developer paper 35 and the leading edge of the latent image on the microcapsule paper 20 are aligned. ing.

The color developer paper 35 has a color developer coated on the surface of the support.
It develops color by reacting with the dye precursor encapsulated in the microcapsules of the microcapsule paper 20, but the details are described in US Pat. No. 4,399,209 and will not be described here.

A heat fixing device 50 is arranged on the right side of the pressure rollers 30a and 30b, a heater 51 is provided inside this heat fixing device 50, and a conveyor belt 52 for conveying the color developer paper 35 is provided at the bottom. is installed.

Next, the liquid crystal exposure apparatus 2 of the present invention will be explained with reference to FIGS. 2 to 4. The liquid crystal exposure apparatus 2 of the present invention generates a spectrum using an optical prism, and selects only light of a necessary wavelength from this spectrum for exposure. In other words, among the light incident on the prism, red (R), which has a long wavelength, has a small refractive index, and blue (B), which has a short wavelength, has a small refractive index.
) has a large refractive index, so the light that passes through the prism produces a spectrum as shown in FIG. 2, and the slit selects only the light of the necessary wavelength from the spectrum.

FIG. 3 is an enlarged view of the liquid crystal exposure device 2 shown in FIG.
, a condenser lens 4 as a condensing means for collimating the light from the halogen lamp 3, and an LCD shutter 5.
, a slit 6 that separates the light transmitted through the LCD shutter 5 into three optical paths, a prism 7, a slit 8 that selects only the light of the required wavelength from the spectrum generated by this prism 7, and an external image signal. and a controller 9 for controlling the LCD shutter 5.

As described above, the LCD shutter 5 is composed of a plurality of liquid crystal light modulation elements, and the liquid crystal light modulation elements are arranged in three rows in the direction perpendicular to the drawing. FIG. 4 is a plan view of this LCD shutter 5, in which the LCD shutter 5 includes a first row of liquid crystal light modulation elements 5R, a second row of liquid crystal light modulation elements 5G, and a third row of liquid crystal light modulation elements. It consists of three sections of light modulation element array 5B. Each of the element rows 5R, 5G, and 5B is independently controlled by a controller 9 in order to perform exposure using the corresponding single colors of red (R), green (G), and blue (B).
The switching control between light transmission and light blocking is performed by this.

Three lights 11 (element array 5 of LCD shutter 5) transmitted through this LCD shutter 5 and separated by a slit 6
Light that has passed through R), 12 (light that has also passed through element array 5G), and 13 (light that has also transmitted through element array 5B) become dispersed light when they exit from prism 7, and their spectra are mixed. The first slit 8a of the slit 8 is set to pass only the light 11R having the wavelength characteristic of R from the spectrum of the light 11. Further, the second slit 8b of the slit 8 is set to pass only the light 12G having wavelength characteristics of G from the spectrum of the light 12. Similarly, the third slit 8C of the slit 8 is
Light 13 with wavelength characteristics B from the spectrum of light 13
It is set to allow only B to pass through. In the present invention, three primary colors with excellent wavelength characteristics can be freely selected by appropriately changing the settings of the slits 8.

Next, the operation of the image recording device 1 will be explained.

When the print start key (not shown) is pressed down, the halogen lamp 3 is turned on, and the light from the halogen lamp 3 is converted into parallel light by the condenser lens 4 and sent to the LC.
The light enters the D shutter 5.

This LCD shutter 5 is controlled by a controller 9 based on an image signal input from the outside. That is, each element row 5R, 5G forming the LCD shutter 5,
5B are independently controlled to form R pixel lines, G pixel lines, and B pixel lines that form an image.

Then, it passes through each element row 5R, 5G, 5B and slit 6.
When the three lights 11, 12, and 13 separated by the prism 7 exit from the prism 7, they become dispersed lights and produce a spectrum. Then, the light 11 is transmitted through the first slit 8a of the slit 8.
From the spectrum, only the light 11R having the wavelength characteristic of R is selected and passes through the slit 8 to reach the microcapsule paper 20. Similarly, from the spectrum of light 12, only light 12G having wavelength characteristics of G, and from the spectrum of light 13, only light 13B having wavelength characteristics of B are selected, pass through slit 8, and reach microcapsule paper 20. Then, the microcapsule paper 20 is simultaneously exposed in a line with the three primary colors R, G, and H. During this exposure, the microcapsule paper 20 stops conveying and is in a stopped state, and after the exposure, the microcapsule paper 20 is moved to the next exposure point by the feed roller 23 and the take-up roller 27 through the slit 8 of the liquid crystal exposure device 2. The pressure rollers 30a, 30 are positioned below the
It is moved slightly in the b direction. Then, a predetermined area of the microcapsule paper 20 is an exposure area 15 below the liquid crystal exposure device 2.
By moving the microcapsule paper 20 once in the direction of the pressure rollers 30a and 30b, the exposure using the three primary colors R, G, and B is completed, and a latent color image is formed on the microcapsule paper 20.

Next, the microcapsule paper 20 is moved to the pressure roller 30a by the driving force of the feed roller 23 and the take-up roller 27.
, 30b. On the other hand, the developer paper 35 is fed one by one by a half-moon roller 41, and is conveyed by a paper feed roller 42 and a paper feed guide 43 to pressure rollers 3Qa and 30b. Then, the exposed surface of the microcapsule paper 20 and the developer-coated surface of the color developer paper 35 are pressed against each other by pressure rollers 30a and 30b in a state where they are superimposed so as to be in contact with each other, and the image is transferred to the color developer paper 35. The color developing paper 35 is further conveyed by a conveyor belt 52 while being accelerated in color development by a heater 51 of a heat fixing device 50, and is output as an image.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit thereof. For example, the light passing through the slit 8 may be reflected by a reflecting mirror and then irradiated onto the microcapsule paper 20 for exposure.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to freely select three primary colors with excellent wavelength characteristics by using an optical prism, and the device can be simplified by not using a filter, while requiring an expensive light source. It is possible to reduce manufacturing costs by not requiring three primary colors R, G,
Since simultaneous line exposure using B can be performed, the exposure time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an image recording device using the liquid crystal exposure device of the present invention, FIG. 2 is an explanatory diagram of the spectral characteristics of a prism, and FIG. 3 is an enlarged view of the liquid crystal exposure device shown in FIG. 1.
FIG. 4 is a plan view of the LCD shutter. DESCRIPTION OF SYMBOLS 1... Image recording device, 2... Liquid crystal exposure device, 3... Halogen lamp, 4... Condenser lens, 5... LCD shutter star 6... Slit, 7... Prism,... Slit , ...controller, ...microcapsule paper (photosensitive recording medium)

Claims (1)

[Scope of Claims] A liquid crystal exposure apparatus that exposes a photosensitive recording medium based on an image signal, the liquid crystal exposure apparatus comprising: a light source; an LCD shutter comprising a plurality of liquid crystal light modulation elements;
A light collecting means for focusing light on the D shutter, a controller for controlling the LCD shutter according to an image signal, a prism, and a light of a predetermined wavelength among the dispersed light transmitted through the prism is irradiated onto a photosensitive recording medium. A liquid crystal exposure device characterized in that it is equipped with a slit for.