JPH0496050A - Liquid crystal exposing device - Google Patents

Abstract

PURPOSE:To remove a color aberration caused by the same lens array and to realize an exposure for a high quality image by moving and arranging an LCD shutter and a selfoc lens array on an optical axis, corresponding to the type of a filter in the optical path. CONSTITUTION:Light emitted from a light source 3, transmits the LCD shutter 4 and further passes any of the filter for red light 5R, the filter for green light 5G, and the filter for blue light 5B which are located in the optical path, transmits a selfoc lens 6, and an photosensitive recording medium 20 is irradiated with it. At this time, the shutter 4 and the lens 6 are moved and arranged in locations corresponding to the type of the filter located in the above- mentioned optical path, by a shutter driving device 7 and a lens driving device 8, respectively, and the focal length of the lens 6 is corrected. Therefore, even if the exposure is carried out with any filters, a formed image on the medium 20 via the lens 6 can be made sharp.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a liquid crystal exposure device equipped with an LCD shutter and a SELFOC lens array, and in particular improves image quality by moving the LCD shutter and SELFOC lens array. The present invention relates to a liquid crystal exposure device capable of high exposure.

[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 orientation II (inside). 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 Since 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, and the alignment of the liquid crystal molecules is twisted by 90 degrees between the two 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.

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 realized.

Focusing on the characteristics of such LCD shutters, we
Various liquid crystal exposure devices using shutters have been developed. Normally, such liquid crystal exposure equipment uses a filter to separate the light from the light source that passes through the LCD shutter into single colors of red, green, and blue, and then uses this light to pass through a SELFOC lens (gradient index lens) array. The image was formed on a photosensitive recording medium and exposed to light. In a liquid crystal exposure apparatus using a SELFOC lens array, a SELFOC lens with a small F number is used in order to increase the efficiency of light quantity.

[Problem to be solved by the invention]

However, when an image is formed on a photosensitive recording medium through a SELFOC lens array, due to wavelength dispersion due to the refractive index distribution of the SELFOC lens, as shown in FIG. red (R)
) light, green (G) light, and blue (B) light each have different meandering periods, which change depending on the position and size of the image or the wavelength.
This results in so-called chromatic aberration. For this reason, there was a problem that the image became blurred and the image quality deteriorated.

Since this chromatic aberration is particularly noticeable in SELFOC lenses with a small F number, there is a problem in that it is difficult to achieve high light intensity (and exposure with high image quality).

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a liquid crystal exposure device that eliminates chromatic aberration caused by SELFOC lenses and enables high-quality image formation.

[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, the liquid crystal exposure apparatus comprising: a light source; an LCD shutter comprising a plurality of liquid crystal light modulation elements; A filter that separates the light from the light source into three colors of red, green, and blue, a SELFOC lens array for condensing the light from the light source, and the LCD shutter depending on the type of the filter located in the optical path. and a lens array drive device that moves the SELFOC lens array along the optical axis.

[Effect]

The light emitted from the light source passes through the LCD shutter, and then passes through any one of the red light filter, green light filter, and blue light filter located in the optical path, and then passes through the SELFOC lens to the photosensitive recording medium. At this time, the LCD shutter is moved by the shutter drive device, and the SELFOC lens is moved by the lens array drive device to a position corresponding to the type of filter located in the above optical path. Since the focal length has been corrected, the image formed on the photosensitive recording medium through the SELFOC lens will be clear no matter which of the above filters is used for exposure.

〔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 LCD shutter 4, and converts the light transmitted through the LCD shutter into red, green, or blue. Filter 5R that separates into single colors.

5G, 5B, SELFOC lens array 6, shutter drive device 7, and lens array drive device 8.

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 21 in a state where it is wound around a cartridge shaft 22. Further, on the right side of this cartridge 21, a feed roller 23, 23 for conveying the microcapsule paper 20 is arranged.

The microcapsule paper 20 that has been exposed in the lower exposure area 15 of the liquid crystal exposure device 2 is pressed by the pressure roller 30a30b while being overlapped with the color developing 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 30a 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 as the half-moon roller 41 rotates, the color developing paper 35 is fed one by one between paper feed rollers 42 and 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.
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 the 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 FIG. FIG. 2 is a drawing for explaining the liquid crystal exposure apparatus 2 shown in FIG. 1. In FIG. 2, the liquid crystal exposure device 2 includes a Haloken lamp 3 as a light source, a condenser lens 3a, an LCD shutter 4, and this L
Filters 5R, 5G, and 5B separate the light transmitted through the CD shutter into single colors of red, green, and blue (in Figure 2, only filter 5R is located in the optical path, and filters 9-5G and 5B are ), a SELFOC lens array 6, a shutter drive device 7 for moving the LCD shutter 4 in the optical axis direction, and a lens array drive for moving the SELFOC lens array 6 in the optical axis direction. A device 8 is provided.

As described above, the LCD shutter 4 is constructed by arranging a plurality of liquid crystal light modulation elements, and usually the area around each liquid crystal pixel is shielded from light by a black mask to prevent leakage current. This LCD shutter 4 is red (R)
is controlled by a controller (not shown) in accordance with an image signal for green (G), an image signal for blue (B), and an image signal for blue (B). In the liquid crystal exposure apparatus 2 of the present invention, the LCD shutter 4 is moved along the optical axis by the shutter drive device 7 depending on the type of filter inserted into the optical path.

The filters 5R, 5G, and 5B are driven by a filter drive device (not shown), and a filter of a color corresponding to the image signal that controls the LCD shutter 4 is inserted into the optical path.

The light transmitted through the LCD shutter 4 is separated into red, green, or blue monochrome by the filters 5R, 5G, and 5B, and is irradiated onto the microcapsule paper 20 by the SELFOC lens array 6. Exposure device 2
Then, depending on the type of filter inserted in the optical path, the SELFOC lens array 6 is connected to the LCD shutter 4 described above.
along the optical axis. The movement of the LCD shutter 4 and SELFOC lens array 6 in the optical axis direction according to the type of filter inserted in the optical path will be described below.

First, when filter 5R is inserted in the optical path,
The LCD shutter 4 is moved and placed at position A by the shutter drive device 7. The light transmitted through the LCD shutter 4 and the filter 5R is red light, and the SELFOC lens array 6 is moved and placed at a focal position A' corresponding to the red light by the lens array driving device 8. Furthermore, when the filter 5B is inserted in the optical path, the light passing through the filter 5B is blue light,
As shown in FIG. 3, the meandering period of this blue light in the SELFOC lens SL is shorter than that of red light. Therefore, the LCD shutter 4 is moved and placed at position B near the microcapsule paper 20 by the shutter driving device 7. Further, the SELFOC lens array 6 is driven by the lens array driving device 8 to drive the microcapsule paper 20.
It is moved closer to the focal point B' and placed at a focal position B' corresponding to blue light. Similarly, when a filter 5G is inserted in the optical path, the light passing through the filter 5G is green light, and the green light has a meandering period intermediate between that of blue light and red light. Therefore, the LCD shutter 4 is moved to a position corresponding to the green light by the shutter drive device 7 (between positions A and B), and the SELFOC lens array 6 is moved to the position corresponding to the green light by the lens array drive device 8. It is moved to and placed at a corresponding focal position (midway between focal position A' and focal position B'). Note that the shutter drive device 7 and the lens array drive device 8 are a filter drive device (not shown).
The controller may automatically move the LCD shutter 4 and SELFOC lens array 6 to a position corresponding to the type of filter in response to the operation of the filter. It may be activated accordingly. Furthermore, the mechanism of the shutter drive device 7 and the lens array drive device 8 may be any mechanism such as a belt drive or a screw drive.

As described above, the LCD shutter 4 and SELFOC lens array 6 move along the optical axis depending on the type of filter inserted into the optical path.
A clear image is formed on the microcapsule paper 20 regardless of whether the exposure is performed using the G or 5B filter.

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 made into parallel light by the condenser lens 3a, and then
The light enters the LCD shutter 4. The LCD shutter 4 is controlled by a controller (not shown) in accordance with a red (R) image signal, and is moved to position A by a shutter drive device 7. Further, a red filter 5R is inserted into the optical path, and in response to this, the self-centering lens array 6 is moved to the focal position flA' by the lens array drive device 8. Then, the light transmitted through the LCD shutter 4 is turned into red light by a red filter 5R, and is irradiated onto the microcapsule paper 20 via the SELFOC lens array 6 to complete the red exposure. Next, the LCD shutter 4 is activated according to the image signal for green (G).
is controlled by a controller (not shown), and the green light transmitted through the green filter 5G in the optical path is irradiated onto the microcapsule paper 20 via the self-clean lens array 6, thereby performing green exposure. At this time, the LCD shutter 4 is moved and placed at a position corresponding to green light (between position A and position B) by the shutter drive device 7, and the SELFOC lens array 6 is moved to a position corresponding to green light by the lens array drive device 8. The lens is moved to a focal position (between focal position A' and focal position B'). Similarly, the LCD shutter 4 is controlled by a controller (not shown) according to the image signal for blue (B), and the blue light that has passed through the blue filter 5B in the optical path is transmitted through the SELFOC lens array 6. The blue light is irradiated onto the microcapsule paper 20 to perform blue exposure. At this time, the LCD shutter 4 is moved and placed at a position B corresponding to blue light by the shutter driving device 7, and the SELFOC lens array 6 is moved to a focal position B corresponding to blue light by the lens array driving device 8.
’ is moved and placed.

When the exposure is completed, the microcapsule paper 20 is conveyed toward the pressure rollers 30a and 30b by the driving force of the feed roller 23 and the take-up roller 27. On the other hand, developer paper 3
5 is fed one by one by a half-moon roller 41, and is moved to pressure rollers 30a, 30 by a paper feed roller 42 and a paper feed guide 43.
transported to b. 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 developer paper 35 is
Furthermore, while being conveyed by the conveyor belt 52, the heat fixing device 5
Color development is promoted by the heater 51 of 0.0 and 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.

〔Effect of the invention〕

As described in detail above, according to the present invention, the shutter driving device
The CD shutter moves on the optical axis, and the lens array driving device moves the SELFOC lens array on the optical axis and places it at the focal position corresponding to the wavelength of the light that passes through the filter. Even when exposure is performed using either a light filter or a blue light filter, the SELFOC lens array and photosensitive recording medium are in an optimal positional relationship, eliminating chromatic aberrations caused by the SELFOC lens array. This makes it possible to achieve high light intensity and high image quality exposure.

6...Selfoc lens array 7...Shutter drive device, 8. Lens array drive device, 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,
A filter that separates into three colors of blue, a SELFOC lens array for condensing light from the light source, and a shutter that moves the LCD shutter along the optical axis depending on the type of the filter located in the optical path. A liquid crystal exposure apparatus comprising: a driving device; and a lens array driving device that moves the SELFOC lens array along an optical axis.