JPH04147243A - Liquid crystal exposing device - Google Patents

Abstract

PURPOSE:To offer a device in which there is no part incapable of exposure and the lowering image quality such as an entire image becomes dark is prevented by allowing a condensing means to project spread light to such an extent that the non-image part of a display panel disappears at the position of a recording medium. CONSTITUTION:The light of a halogen lamp 3 is efficiently condensed by a reflector 2 and a condenser 4, and irradiates an LCD 6 through an infrared cur filter 5 and a red filter 22R. In such a case, the condensed light is not parallel rays of light and made incident on the panel so that it may spread to such an extent that the non-image part disappears on the photosensitive recording medium. The light transmitted through the display part 21 which is irradiated with the spread light forms an image on a microcapusle paper 7 while it spreads in a light transmissive plate 24. At such a time, the non- display part 22 narrows little by little and mostly disappears on the microcapusle paper, then the lowering of the image quality such as the entire image becomes dark is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal exposure device for a liquid crystal printer that prints out video signals, image data from a personal computer, etc. as an image.

[Conventional technology]

In recent years, various liquid crystal display elements (L C
D) A 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 converting side strand 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 is linearly polarized by the first polarizing plate. Then, 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.

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, it is possible to achieve fast response speed.

Next, explanation will be given using FIG.

The display section 21 is arranged between the light transmitting plates 23 and 24, and an image of the display section 21 is formed on the microcapsule paper 7.

According to this method, the light transmitted through the display area 21 hardly spreads and forms an image on the microcapsule paper 7, and the non-display area 22
is imaged on the microcapsule paper 7 as an area that cannot be exposed to light.

[Problem to be solved by the invention]

As described above, since the liquid crystal display panel and the photosensitive recording medium were exposed in close contact using nearly parallel light as an exposure light source, non-image areas were not exposed. However, if there is a portion of the output image that cannot be exposed, there is a problem that the entire image becomes dark and the image quality deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a liquid crystal exposure apparatus that does not have any portions that cannot be exposed and does not deteriorate image quality due to darkening of the entire image.

[Means to solve the problem]

The present invention comprises a light source having a wavelength necessary for exposing a photosensitive recording medium, a condensing means for reflecting or refracting the light from the light source, and a plurality of liquid crystal cells that can be controlled according to the image to be recorded. In a liquid crystal exposure apparatus comprising a liquid crystal display panel consisting of
It is configured to irradiate a spread light to the extent that the non-image area of the liquid crystal display panel disappears.

[Effect]

The light source of the liquid crystal exposure apparatus of the present invention having the above configuration has a wavelength necessary for exposing a photosensitive recording medium. The condensing means condenses the light emitted from the light source in order to utilize it efficiently. This light is focused so that the emitted light is not parallel light but spreads out to the extent that non-pixel areas disappear on the photosensitive recording medium, and the focused light is incident on the liquid crystal display panel. The liquid crystal display panel is controlled according to the image to be recorded, and the light transmittance changes for each cell. Since the light transmitted through the liquid crystal display panel spreads out, when it reaches the photosensitive recording medium, it is exposed with non-pixel areas erased. The latent image formed by exposure is developed and output as an image.

〔Example〕

Hereinafter, embodiments embodying the present invention will be described.

In the liquid crystal exposure apparatus 1 of this embodiment shown in FIG. 1, a photosensitive recording medium consisting of a photosensitive pressure sensitive paper 7 (hereinafter referred to as microcapsule paper) and a color developer paper 8 is used.

Note that microcapsules are coated on the surface of the support of the microcapsule paper 7 used in this example.
The microcapsules contain a dye precursor that reacts with a color developer, which will be described later. A color developer is coated on the surface of the support of the color developer paper 8 and develops color by reacting with a dye precursor.
It is described in the specification of No. 9, etc., and is omitted here. A halogen lamp 3 is arranged as an exposure light source, and a beam flap 2 is arranged above it. Further, a condenser lens 4 is arranged below the halogen lamp 3, and an infrared cut filter 5 is further arranged below it. Below the infrared cut filter 5 are color filters 22R, 22.
A filter unit 22 consisting of G and 22B, and a liquid crystal display panel 6 (hereinafter referred to as LCD) are provided.

The light-shielding cartridge 18 contains unexposed microcapsule paper 7 wound around the cartridge shaft 15. A feed roller 19 is arranged on the right side of the cartridge 18. Microcapsule paper 7 is LCD
6 is exposed while stationary, and a latent image is formed. The microcapsule paper 7 passes between pressure rollers lla and llb and is wound around a winding shaft 16.

A half-moon roller 9 is arranged above the color developer paper 8, and a paper feed roller 10 and a paper feed guide 17 are arranged on the left side. Further, a heat fixing device 12 is provided below the color developer paper 8, and a heater 13 is provided inside the heat fixing device 12, and a conveyor belt 14 is provided below.

Next, the operation of the liquid crystal exposure apparatus 1 will be explained.

First, when a print start key (not shown) is pressed, an image corresponding to an image signal input from the outside is displayed on the LCD 6. Next, the halogen lamp 3, which is a light source, is turned on. The light beam of the halogen lamp 3 is efficiently condensed by the deflector 2 and the condensing lens 4 to form light with a predetermined spread, and is irradiated onto the LCD 6 via the infrared cut filter 5 and the red filter 22R. The stationary microcapsule paper 7 is exposed to light selected by the LCD 6, which is controlled according to the red signal of the image to be recorded.

As shown in FIG. 4, the LCD 6 has a plurality of liquid crystal light modulation elements (cells), which are display sections 21, arranged in a row, and a black mask 22 around each liquid crystal pixel 21 to prevent leakage current.
The light is blocked by In the illustrated example, rectangular liquid crystal pixel 2
1 is used, and the black mask 22 has a grid shape. The liquid crystal image 21 and the black mask 22 are sandwiched between light transmitting plates 23 and 24 made of polarizing plates, reinforcing glass, or the like.

According to FIG. 2 in which spread light is irradiated, the light transmitted through the display section 21 forms an image on the microcapsule paper 7 while spreading within the light transmitting plate 24 . At this time, the non-display area 22 gradually becomes narrower and disappears on the microcapsule paper 7. Therefore, the necessary spread angle of light is determined according to the thickness of the light transmitting plate 24, and when the light transmitting plate 24 is thick, the light has a small spread, and when the light transmitting plate 24 is thin, the light has a large spread. It is necessary to irradiate it with light.

When the red exposure is completed, the red filter 22R is replaced with the green filter 22G, the red signal of the LCD 6 is switched to a green signal, and exposure is performed in the same manner. The same applies to blue, and the halogen lamp 3 is turned off after three exposures are completed. In this way, a color latent image is formed on the microcapsule paper 7. Next, the microcapsule paper 7 is sent toward the pressure rollers lla and llb by the driving force of the take-up roller 16 and the feed roller 19. On the other hand, the developer paper 8 is fed one by one by a half-moon roller 9, passes through a paper feed guide 17, and is moved by a paper feed roller 10 to pressure rollers lla, l.
Sent up to lb. With the exposed surface of the microcapsule paper 7 and the color developer coated surface of the color developer paper 8 facing each other, press the pressure roller ll.
The image is transferred to the color developer paper 8 by pressure applied by a and llb. The color developing paper 8 is further conveyed by a conveyor belt 14, and color development is promoted by a heat fixing device 12 equipped with a heater 13, and the color is output as an image.

The present invention is not limited to the embodiments described in detail above, and various changes can be made without departing from the spirit thereof. For example, in this embodiment, a color filter is used to create a color liquid crystal exposure device, but the color filter may be omitted and a monochrome liquid crystal exposure device may be used.

〔Effect of the invention〕

As is clear from the detailed explanation above, since the light condensing means irradiates light so spread out that the non-pixel areas of the liquid crystal display panel disappear at the position of the photosensitive recording medium, there are no areas that cannot be exposed. , the image quality does not deteriorate, such as the entire image becoming dark.

[Brief explanation of drawings]

1 to 2 show embodiments embodying the present invention; FIG. 1 is an overall configuration diagram of a liquid crystal printer;
The figure is an enlarged view of the vicinity of the LCD, and FIGS. 3 and 4 are enlarged views of the LCD in the prior art. 1...Liquid crystal printer,...Reflector, 3...Halogen lamp, 4...Condensing lens.

Claims (1)

[Claims] A liquid crystal consisting of a light source with the wavelength necessary for exposing a photosensitive recording medium, a condensing means for reflecting or refracting the light from the light source, and a plurality of liquid crystal cells that can be controlled according to the image to be recorded. A liquid crystal exposure device comprising a display panel, wherein the light converging means is configured to irradiate a spread light to the extent that a non-image area of the liquid crystal display panel disappears at the position of the photosensitive recording medium.