JPH0496044A - Liquid crystal exposing device - Google Patents

Abstract

PURPOSE:To split light into two parallel optical paths, to actually enhance the opening of an LCD shutter, to obtain high resolution, and to attain shortcut structure and reduction in producing cost by constituting a reflection mirror with a half reflection mirror and a total reflection mirror laminated. CONSTITUTION:The LCD shutter 4 is arranged in such a manner that the circumference of plural liquid crystal optical modulation elements 4a is shielded from light beams with a black mask 4b. The light beams transmitting the shutter 4 is split to the single colors of red, green, and blue by filters 5R, 5G, and 5B, turned into parallel light beams by an optical lens 6, and made incident on the reflection mirror 7. The mirror 7 is constituted that the half reflection mirror 7a and the total reflection mirror 7b are laminated, so that each of 50% of the incident light is reflected on the top and bottom surfaces of the mirror 7, and passes two parallel optical paths, and a microcapsule sheet 20 is irradiated with it. The thickness, reflectance, incident angle, etc., of the mirror 7a are properly selected, so that an exposure is carried out in one direction of the projected part of the black mask 4b, and an actual numerical aperture can be enhanced.

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. This invention relates to a liquid crystal exposure device with improved shutter aperture ratio.

[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.
) 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 adopt a specific alignment state due to the force regulated by the grooves of the alignment films, but the groove directions of the two alignment films are mutually Because the liquid crystal molecules are shifted by 90 degrees, the liquid crystal molecules exhibit a twisted structure in the long axis direction of the molecules.
The alignment of liquid crystal molecules is twisted by 90 degrees between both alignment films.

When the TN liquid crystal light modulator 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, due to the birefringence of the liquid crystal molecules and the above-mentioned 90 degree twisted alignment structure,
The polarization direction of the above linearly polarized light is rotated by 90 degrees. 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 will reach the other polarizing plate without causing any rotation of the polarization direction, and the polarization direction of the linearly polarized light and the polarization direction of the other polarizing plate will be orthogonal to each other at the time of output. The light will be blocked.

The switching between light transmission and light blocking as described above is performed by applying a voltage between the transparent electrodes. By arranging a plurality of liquid crystal light modulation elements, a shutter with high response speed can be achieved.

Focusing on the characteristics of such LCD shutters, we
Various liquid crystal exposure devices using shutters have been developed.

[Invention or problem to be solved]

However, in the above-mentioned LCD shutter, light is shielded from light by a black mask except for the liquid crystal light modulation element (liquid crystal pixel) in order to prevent leakage current. For example, if square liquid crystal pixels are used and the distance between adjacent liquid crystal pixels is the same as one side of the square, the ratio of the total area of the liquid crystal pixels to the total area of the LCD shutter (aperture ratio) is 25.
%, and the remaining 75% is shielded from light by the black mask and becomes a non-exposed portion. For this reason, there was a problem in that the black mask portion was projected black during exposure, resulting in a reduction in resolution. Furthermore, when an LCD shutter with a high aperture ratio is used to increase the resolution, 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 because it does not use an LCD shutter with a predetermined aperture ratio, it is possible to perform exposure with the same high resolution as using an LCD shutter with a higher aperture ratio. It is an object of the present invention to provide a liquid crystal exposure device that has a simple structure and can reduce manufacturing costs.

(Means for Solving the Problems) In order to achieve such an object, the present invention provides a liquid crystal exposure device that exposes a photosensitive recording medium based on an image signal, and the liquid crystal exposure device includes a light source and a plurality of liquid crystal light beams. The LCD shutter consisting of a modulation element and the light from the light source are red,
A configuration including a filter that separates the light into three colors of green and blue, a condensing means for condensing the light from the light source, and a reflective mirror configured by superimposing a semi-reflective mirror on a total reflective mirror. And so.

[Effect]

The light emitted from the light source and transmitted through the LCD shutter is separated by a filter into single colors of red, green, and blue, and is focused by a condensing means and incident on the reflecting mirror, with half of the incident light being reflected in front of the reflecting mirror. The light is reflected by the semi-reflective mirror that constitutes the mirror and is irradiated onto the photosensitive recording medium, and exposure corresponding to the arrangement of the liquid crystal light modulation elements of the LCD shutter is performed.On the other hand, half of the light incident on the reflecting mirror The light passes through the interior, is totally reflected by the total reflection mirror that forms the rear surface of the reflection mirror, and is irradiated onto the photosensitive recording medium through another optical path parallel to the optical path of the light reflected by the above-mentioned semi-reflection mirror. .

As a result, the photosensitive recording medium is exposed to light corresponding to the arrangement of the liquid crystal light modulation elements of the LCD shutter, and furthermore, an area other than this exposure area is exposed.

〔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 liquid crystal exposure device 2 includes a halogen lamp 3 as a light source, a condenser lens 3a that converts the light emitted from the halogen lamp 3 into parallel light, an SLCD shutter 4, and a monochromatic color of red, green, or blue from the light transmitted through the LCD shutter. Filter 5R that disassembles.

5G, 5B, an optical lens 6 as a condensing means, and a reflecting mirror 7.

The microcapsule paper 20 has a plurality of microcapsules coated on the surface of a long support, and the microcapsules contain a dye precursor or the like that reacts with a color developer described later. And unexposed microcapsule paper 20
is mounted in a light-shielding cartridge 21 in a state where it is wound around a cartridge shaft 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 been exposed in the exposure area 15 below the liquid crystal exposure device 2 is pressed by the pressure roller 30a30b while being overlapped with the color developer paper 35, and is subjected to pressure development. Thereafter, the microcapsule paper 20 separated from the developer paper 35 is wound around a cartridge shaft 27 disposed within the cartridge 26.

Above the pressure rollers 3Qa and 30b, a plurality of color developing papers 3
A cassette 37 containing five cassettes stacked one on top of the other is installed. A half-moon roller 41 is disposed at the upper left of the cassette 37, and the rotation of the half-moon roller 41 feeds out the developer paper 35 one by one between paper feed rollers 42, 42. The fed out developing paper 35 is fed to the feed guide 4
3, and is conveyed to pressure rollers 30a and 30b 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.

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

A heat fixing device 50 is arranged to the right of the pressure rollers 30a and 30b, a heater 51 is provided inside the heat fixing device 50, and a transport heald 52 for transporting the color developing paper 35 is provided at the bottom. or is arranged.

Next, the liquid crystal exposure apparatus 2 of the present invention will be explained with reference to FIGS. 2 to 4. FIG. 2 is a diagram for explaining the liquid crystal exposure apparatus 2 shown in FIG. It includes filters 5R, 5G, and 5B that separate the light transmitted through the shutter into monochromatic colors of red, green, and blue, an optical lens 6 as a focusing means, and a reflecting mirror 7.

The LCD shutter 4 is constructed by arranging a plurality of liquid crystal light modulation elements as described above. Figure 3 shows this LC
This is a plan view of the D shutter 4. The LCD shutter 4 is arranged with liquid crystal light modulation elements (liquid crystal pixels) 4a, and a black mask 4 is provided around each liquid crystal pixel 4a to prevent leakage current.
The light is blocked by b. In the illustrated example, the length of the short side is β
A rectangular liquid crystal pixel 4a is used, and the width of the black mask 4b in the short side direction (arrow A direction) of the liquid crystal pixel 4a is also β. The LCD shutter 4 shown in FIG. 3 is configured to coincide with the direction of the arrow A described above or the direction of the arrow in FIG.

The light transmitted through this LCD shutter 4 is filtered through a filter 5.
The light is separated into monochromatic colors of red, green, or blue by R, 5G, and 5B, and is converted into parallel light by an optical lens 6 and enters a reflecting mirror 7. This reflection mirror 7 is constructed by superimposing a semi-reflection mirror 7a and a total reflection mirror 7b. Therefore, 50% of the light incident on the reflection mirror 7 is reflected by the semi-reflection mirror 7a forming the front surface of the reflection mirror 7, passes through the optical path P, and is irradiated onto the microcapsule paper 20. The interval between the optical paths P1 of the respective lights transmitted through each liquid crystal pixel corresponds to the arrangement of the liquid crystal pixels 4a of the LCD shutter 4.

Furthermore, 50% of the light incident on the reflection mirror 7 passes through the semi-reflection mirror 7a. Then, it is totally reflected by the total reflection mirror 7b constituting the rear surface of the reflection mirror 7, and the optical path P
Microcapsule paper 2 passes through optical path P2 parallel to
0 is irradiated.

Here, the thickness of the semi-reflecting mirror 7a is a1, the refractive index of the atmosphere is n, the refractive index of the semi-reflecting mirror 7a is n2, the angle of incidence on the reflecting mirror 7 is θ, and the refraction of light passing through the semi-reflecting mirror 7a is If the angle is 02, the above optical path P and optical path P
The deviation amount α of 2 is expressed by the following formula.

a=2a tanθ ・C05 (90°-θl) (however, n/n2=sinθ, /sinθ2) Therefore,
As shown in FIG.
), the length of the liquid crystal pixel 4a and the width of the black mask 4b are set to be the same dimension β, and by setting the relationship α-β, an optical path P2 is formed in the black projection area by the black mask 4b in one direction (short side direction A). The light passing through can perform the same projection as the liquid crystal pixel 4a. That is, on the microcapsule paper 20, as shown in Fig. 4, one direction (A) of the projected portion of the black mask 4b is exposed to light, and the aperture ratio is substantially increased and the resolution is improved. do.

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

When a print start key (not shown) is pressed down, the halogen lamp 3 is turned on, and the light from the halogen lamp 3 is made into parallel light by the condenser lens 3a, and then enters the LCD shutter 4. This LCD shutter 4 is operated by a controller (
(not shown). The light transmitted through the LCD shutter is converted into red light by a red filter 5R, converted into parallel light by an optical lens 6, and then enters a reflection mirror 7. In this reflecting mirror 7, 50% of the red light
is reflected by the semi-reflecting mirror 7a and irradiated onto the microcapsule paper 20 through the optical path P1, and the remaining 50 red lights
% passes through the semi-reflection mirror 7a, is reflected by the total reflection mirror 7b, passes through the optical path P2, and is irradiated onto the microcapsule paper 20.

By setting α-β as described above, the microcapsule paper 2
One direction (A
) is exposed and the high-resolution red exposure is completed. Next, a green filter 5G is applied according to the green (G) image signal.
Green exposure is performed using Similarly, blue (B)
Blue exposure is performed using the blue filter 5B according to the image signal for the image. As a result, a latent color image is formed on the microcapsule paper 20. During this time, the microcapsule paper 20 stops being conveyed and is in a stopped state.

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 to pressure rollers 30a and 30b by a paper feed roller 42 and a paper feed guide 43. 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 while being superimposed so as to be in contact with each other, and the image is transferred onto the color developer paper 35. The color developing paper 35 is further transported by the transport heald 52, and color development is promoted by the heater 51 of the heat fixing device 50, and the image is output.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit thereof.

〔Effect of the invention〕

As described in detail above, according to the present invention, the optical path of the light reflected by the semi-reflective mirror constituting the reflective mirror and the optical path of the light reflected by the total reflective mirror constituting the reflective mirror are parallel to each other. By taking advantage of the separate optical paths, it is possible to substantially increase the aperture of the LCD shutter and perform high-resolution exposure, and the structure of the LCD exposure device is simple and manufacturing costs can be reduced. The effect that there is is produced.

[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 liquid crystal exposure device shown in FIG. 1, and FIG. 3 is a partial plan view of an LCD shutter. 4
The figure shows the exposure state on microcapsule paper. DESCRIPTION OF SYMBOLS 1... Image recording device, 2... Liquid crystal exposure device, 3... Halogen lamp, 3a... Condenser lens, 4... LCD shutter 5R5G 5B... Filter 6... Optical lens, 7 ...Reflection mirror 7a...Semi-reflection mirror 7b...Total reflection mirror 20...Microcapsule paper (photosensitive recording medium).

Claims (1)

[Claims] A liquid crystal exposure device that exposes a photosensitive recording medium based on an image signal, the liquid crystal exposure device comprising: a light source; an LCD shutter comprising a plurality of liquid crystal light modulation elements; green,
It is characterized by comprising a filter that separates the light into three colors of blue, a condensing means for condensing the light from the light source, and a reflective mirror configured by superimposing a semi-reflective mirror on a total reflective mirror. LCD exposure equipment.