JPS6143718A - Image recorder - Google Patents

Abstract

PURPOSE:To eliminate blur and the variance of density in an image recorder to obtain a high-contrast image by condensing the light emitted from a spot light source by a cylindrical lens system to illuminate an optical shutter linearly. CONSTITUTION:The light emitted from a spherical halogen lamp 10 passes a stop 11, the first cylindrical lens 12, the second cylindrical lens 13, and the third cylindrical lens 14 successively and is made incident on a liquid crystal optical shutter 15. The first cylindrical lens 12 and the third cylinrical lens 14 are so arranged that their cylindrical surfaces face each other, and these cylindrical surfaces are extended in the lengthwise direction of the liquid crystal shutter 15 to illuminate the liquid crystal optical shutter 15 linearly. The second cylindrical lens has the cylindrical surface extended in the direction orthogonal to the first cylindrical lens 12 and controls the spread in the lengthwise direction of the linear illumination.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording apparatus that records an image on a photosensitive material using an optical shutter.

[Prior art]

The optical shutters include liquid crystal optical shutters and lanthanum-doped lead zirconium titanates (PLZT).
) optical shutters are known, and the light transmittance of any of these can be changed by applying an electric field. Image recording devices use an optical shutter array in which pixel forming sections (macro shutters) each consisting of a set of minute transparent electrodes are arranged in a row, or an optical shutter matrix in which pixel forming sections are arranged two-dimensionally. and these are placed between the light source system and the photosensitive material. When recording an image, the photosensitive material is transported, and when stopped, multiple pixel forming sections are selectively driven according to the image information, and the photosensitive material is exposed to light that has passed through the transparent pixel forming sections. Then, the image of the dot pattern is recorded as a latent image on the photosensitive material.

A conventional image recording apparatus uses a light source system composed of a bar-shaped light source extending in the line direction of an optical shutter and a reflecting mirror placed behind the bar-shaped light source. but,
Since it is difficult for this rod-shaped light source to uniformly illuminate the optical shutter, density unevenness is likely to occur in images recorded on the photosensitive material.

In addition, in the case of a rod-shaped light source, some light enters the optical shutter at a large incident angle, which reduces contrast and causes blurring of characters recorded on photosensitive materials, making it difficult to obtain high-quality images. I couldn't do it.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image recording apparatus capable of obtaining high-contrast images without bleeding or density unevenness.

[Structure of the invention]

In order to achieve the above object, the present invention provides, as a light source system,
It is characterized in that the optical shank is illuminated in a line by using a point light source and a cylindrical lens system that focuses the light emitted from the point light source in two orthogonal directions.

〔Example〕

1 and 2 show a first embodiment of the present invention. The light emitted from the spherical halogen lamp 10 passes through the aperture 11. First cylindrical lens 12, second cylindrical lens 13. The light passes sequentially through the third cylindrical lens 14 and enters the liquid crystal light shutter 15 . The diaphragm 11 is for blocking diffused light and stray light from the spherical halogen lamp 1O, thereby making the spherical halogen lamp 10 essentially a point light source. the first cylindrical lens 12;
The third cylindrical lens 14 is arranged so that its cylindrical surfaces face each other, and the cylindrical surface extends in the longitudinal direction of the liquid crystal light shutter 15, and illuminates the liquid crystal light shutter 15 in a line shape. Further, the second cylindrical lens 13 has a cylindrical surface extending in a direction perpendicular to the first cylindrical lens 12, and restricts the spread of the linear illumination in the longitudinal direction. In general, the liquid crystal light shutter 15 has a characteristic that the contrast ratio between the transparent state and the blocked state changes depending on the incident angle, and the contrast ratio becomes good when the incident angle is within 10 degrees. Therefore, the second cylindrical lens 13 suppresses the spread angle θ2 of light to 10 degrees, and the third cylindrical lens 14 suppresses the convergence angle θ1 to 10 degrees.

The light passing through the liquid crystal light shutter 15 is focused onto a photosensitive lens 17 by a graded fiber array 16. Note that the graded type fiber array 16 is preferably arranged with a diffuser plate in front of the liquid crystal light shutter 15 because a better image without the influence of coma aberration can be obtained if the incident light has a weak scattering property.

FIG. 3 shows a liquid crystal light shutter. This liquid crystal light shutter 15 has a large number of ii! It consists of an array of three rows in which i-element forming parts are arranged in a line, the upper row is the blue pixel forming part 20, and the middle row is the green pixel forming part 20.
This is the i-element forming section 21, and the one in the lower row is the red pixel forming section 22.

FIG. 3 shows a pixel forming portion of a liquid crystal optical shutter, and since this is well known, a brief explanation will be provided.

A transparent upper glass plate 25 and a lower glass plate 26 are arranged facing each other with a sealing material 27 in between, and a twisted liquid crystal (hereinafter referred to as TN liquid crystal) 2 is placed between them.
8 is included. On the inner surfaces of the upper glass Fi 25 and the lower glass plate 2G, a large number of horizontal electrodes 29 are arranged in an array.
and vertical electrodes 30 are formed. An alignment film (not shown) is formed on these electrodes 29 and 30 to align the molecules of the TN liquid crystal 28 in one direction.

Since the alignment directions of this pair of alignment films are shifted by 90 degrees, the molecules of the TN liquid crystal 28 are twisted by 90 degrees. The glass plate 25.2G includes a polarizing plate 32.33.
are in close contact with each other, and these polarizing plates 32 and 33 are arranged so that their polarization axes coincide with the alignment direction of the alignment film of the glass plate 25). On this polarizing plate 32, a blue filter 34, a green filter 35, and a red filter 36 are deposited on the horizontal electrode 29. Alternatively, an opaque mask having openings corresponding to the color filters 34 to 36 may be provided on the lower surface of the two-part glass plate 25.

There is no light on the pixel forming portions 20 to 22 of the liquid crystal light shutter 15! 14, first, only the light corresponding to the color passes through the color filters 34 to 36 and reaches the polarizing plate 3. Then, only the component that matches the polarization direction of this polarizing plate 32 is transmitted through this 2, and then passes through the TN type liquid crystal 28 to reach the polarizing plate 33 located below it. Here, when no voltage is applied to the transparent electrodes 29 and 30, the TN type liquid crystal 28 is twisted by 90 degrees, so this TN type liquid crystal 28
The linearly polarized light that has passed through is blocked by the polarizing plate 33. However, when a voltage is applied to the transparent electrodes 29 and 30, the molecules of the TN liquid crystal 28 are untwisted depending on the applied voltage. In the vicinity where the applied voltage slightly exceeds the dark value, the transmittance changes linearly according to the applied voltage. When a voltage exceeding this dark value to some extent is applied, the polarization axis of the TN liquid crystal 28 is rotated by 90 degrees, the molecules are aligned along the direction of the electric field, and the transmittance is maximized. Note that if the polarizing plate 33 is arranged in a direction perpendicular to the polarizing plate 32, it will be in a transparent state when no voltage is applied, and will be in an opaque state when a voltage is applied. This type has a response characteristic that is advantageous for expressing images with gradations. Further, it is necessary to drive the liquid crystal light shutter 15 before lighting the spherical halogen lamp 10, or to provide a mechanical shutter before or after the liquid crystal light shutter 15.

Next, the operation of the above-mentioned embodiment will be briefly explained. The light emitted from the spherical halogen lamp 10 passes through the pinhole of the diaphragm 11 and enters the first cylindrical lens 12, and the spread of the light in the direction perpendicular to the line of the liquid crystal light shutter 15 is restricted. The light that has passed through the first cylindrical lens I2 is restricted from spreading in the line direction of the liquid crystal light shutter 15 by the second cylindrical lens 13, and is then passed through the third cylindrical lens 14.
incident on . This third cylindrical lens 14 focuses light in a direction perpendicular to the line of the liquid crystal light shutter 15. These first and third cylindrical lenses 12-1
4, the light emitted from the spherical halogen lamp IO is incident on the liquid crystal light shutter 15 at an angle within 10 degrees.

In this way, when the incident angle is regulated to within 10 degrees, the transmittance increases due to the viewing angle characteristics of the TN liquid crystal, and an image with a high contrast ratio can be obtained. If this contrast ratio is increased, the control range of transmittance by applied voltage is expanded accordingly. As a result, the ability to express midtones increases,
This is advantageous when recording images with halftones such as photographic images.

When recording an image, the photosensitive material 17 is intermittently advanced by one pixel using a stamping motor (not shown), and each pixel forming section 20 to 22 of the liquid crystal optical shank 15 is moved in accordance with the image information while the feeding is stopped. Drive selectively. Here, the green pixel forming section 21 has one pixel forming section 21 for the blue pixel forming section 20.
There is a shift of iii elements, and the red pixel forming part 2
2 is shifted by two pixels, it is necessary to delay the green and red signals of the original pixels by a time corresponding to the shift before supplying them to the respective pixel forming sections. The light transmitted through each of the pixel forming sections 20 to 22 that have changed to a transparent state enters the photosensitive material 17 and exposes it. Note that the photosensitive material 17 may be fed continuously to emit light without being fed intermittently.

FIG. 5 shows a second embodiment 11 of the present invention, in which a cold mirror 40 is arranged at an angle of 45 degrees between a spherical halogen lamp IO.

In this embodiment, since infrared light can be removed by the cold mirror 40, a delay in the rise of the liquid crystal light shutter I5 due to temperature can be eliminated. Note that the same members as in the embodiment shown in FIGS. 1 and 2 are given the same reference numerals.

FIG. 6 shows a three-color sequential exposure type color image recording apparatus, in which the same members as in the first embodiment described above are given the same reference numerals. In this embodiment, a turret 42 is disposed between the f,1:-shaped halogen lamp 10 and the first silicate/trical lens 12. This Tale Cito 42
As illustrated in FIG. Three color lights are selectively extracted from the light and enter the liquid crystal light shutter 46.

Since the guichroic mirrors 43 to 45 can cut out infrared light, there is no cold mirror and it is possible to use a spherical halogen lamp with high brightness.The turret 42 is It is rotated by a motor, for example, a stenting motor 47, by 120 degrees, and the blue dichroic mirror 43, the green dichroic mirror 44, and the red dichroic mirror 45 are sequentially inserted into the optical path to perform three-color sequential exposure. , 1, and 3 colors are sequentially exposed, the photosensitive material 17 is transferred intermittently.The turret 42 and the photosensitive material 17 are transferred continuously.
Alternatively, the exposure may be performed by driving the recording medium to light, and in this case, high-speed recording becomes possible.

FIG. 8 shows the liquid crystal optical shutter shown in FIG. In this liquid crystal light shutter 46, a large number of pixel forming portions 48 are arranged in a line in a direction perpendicular to the direction in which the photosensitive material 17 is transported.

FIG. 9 shows an embodiment in which a filter is inserted into the optical path to perform three-color sequential exposure. In this example,
Spherical halogen lamp 10 and first cylindrical lens 1
2, a cold mirror 40 tilted at 45 degrees,
A rotatable turret 50 is arranged. As shown in FIG. 10, this turret 50 has a blue filter 51, a green filter 52, and a red filter 53 affixed to each opening 1'', and is rotated by 120 degrees by a steering motor 54. , filters 51 to 53 are sequentially inserted into the optical path.

FIG. 11 shows a cylindrical lens 57 having two cylindrical surfaces 55 and 56. This cylindrical lens 57 is used in place of the first to third cylindrical lenses 12 to 14 described above.

〔Effect of the invention〕

The present invention having the above configuration uses a cylindrical lens to condense light from a point light source into a line and input it to the optical shutter, so there is less unevenness in illuminance compared to a conventional light source system using a rod-shaped light source. Moreover, since there is no scattered light or stray light, clear images without blur can be recorded. Furthermore, since the angle of incidence of light onto the shutter is regulated by the cylindrical lens, it is possible to obtain an image with a high contrast ratio.

[Brief explanation of drawings]

FIG. 1 is a side view showing an image recording apparatus of the present invention, and FIG. 2 is a plan view thereof. FIG. 3 is a perspective view showing the liquid crystal light shutter. FIG. 4 is a sectional view taken along the line A--A in FIG. 3. FIG. 5 is a side view showing an embodiment in which a cold mirror is provided. FIG. 6 is a side view showing an embodiment in which a guichroic mirror is rotatably arranged. FIG. 7 is a plan view of the turret shown in FIG. 6. FIG. 8 is a perspective view of a liquid crystal optical shutter used in the embodiment shown in FIG. FIG. 9 is a side view showing an embodiment using color filters. FIG. 10 is a plan view of the turret shown in FIG. 9. FIG. 11 is a perspective view of a cylindrical lens with cylindrical surfaces formed on both sides. 10... Spherical halogen lamp 1 l... Aperture 12 to 14... Cylindrical lens 15... Liquid crystal light shutter 1G... Graded type fiber array 17... Photosensitive material 20... Pixel forming section 21 for dark color... Green pixel forming section 22... Red pixel forming section 25, 26... Glass plate 2... TN type liquid crystal 32, 33... Polarizing plates 34 to 35... Color filter 40... Cold mirror 43 to 45.・Color filter 46 ・Liquid crystal light shutter 48 ・Pixel forming parts 51 to 53 ・Gicroic mirror 57 ・Cylindrical lens. Figure 1 It) Figure 11 Procedure Neff? Original September 7, 1981

Claims (4)

[Claims] (1) A light shutter consisting of a plurality of pixel formation sections arranged in at least one line is placed between the light source system and the photosensitive material, and the light passing through the pixel formation sections in a transparent state forms a dot pattern on the photosensitive material. An image recording device for recording an image on an image, characterized in that the light source system includes a point light source and a cylindrical lens system that collects light emitted from the point light source and illuminates an optical shutter in a line. Image recording device. (2) The cylindrical lens system includes a first cylindrical lens that focuses light in the line direction of the optical shutter, and is arranged before and after the first cylindrical lens, and focuses light in a direction perpendicular to the line direction of the optical shutter. 2. The image recording apparatus according to claim 1, comprising second and third cylindrical lenses. (3) The cylindrical lens system has a first cylindrical surface that focuses light in the line direction of the optical shutter, and a second cylindrical surface that focuses light in a direction perpendicular to the line direction of the optical shutter. 2. The image recording device according to claim 1, wherein the image recording device is a cylindrical lens. (4) The point light source is comprised of a spherical halogen lamp and an aperture that removes scattered light and stray light components from the light emitted from the lamp. The image recording device described.