JPS5810742A - Picture scanning recording device - Google Patents

Abstract

PURPOSE:To modulate optical beams in accordance with a picture signal to record a halftone plate picture, by making optical beams, which are formed flat by an optical beam flat forming equipment, incident to an acoustooptic optical modulator where plural ultrasonic exciting parts are arranged in parallel on one acoustooptic medium. CONSTITUTION:Optical beams, whose sectional shape is round approximately, from a light source 24 are made incident to an optical beam flat forming equipment 27 consisting of a pair of cylindrical lenses 25 and 26 and the are converted to flat optical beams suitable for the incidence plane of an acoustooptic optical modulator 28 and are incident to the optical modulator 28. A part of these incident optical beams is modulated in accordance with a dot forming signal generated in a dot forming circuit and is emitted as the primary light and the 0- order light. Only the primary light is projected to a film 30 on a recording cylinder with a prescribed reduction magnification by a focusing lens system 29 to form a row of minute light points, thus recording a halftone plate picture by copying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image scanning recording apparatus that controls an exposure means on the recording side using an image signal obtained by photoelectrically scanning an original image to record a copy of a halftone image on a photosensitive material. In particular, multiple light beams are used as exposure means on the recording side, and these light beams are transmitted through an acousto-optic light modulation element in which multiple ultrasonic and acoustic wave excitation parts are arranged side by side on a single acousto-optic medium. The present invention relates to an apparatus for duplicating and recording halftone images by independently modulating them according to one image signal.

For example, as disclosed in Japanese Patent Publication No. 52-33523, a light beam from a light source is divided into a plurality of light beams by a combination of a half mirror and a mirror, and each light beam is divided according to an image signal from an original image. A method of recording a halftone image by independently controlling each light beam using an electro-optic light modulation element arranged correspondingly to each other; As disclosed in Japanese Patent Publication No. 52, a light beam from a light source is split into a plurality of light beams by a light beam splitting device having a parallel plane plate coated with a special coating. Similar to the method disclosed in Japanese Patent No. 33523, a method is known in which a halftone image is recorded by independently controlling each element using electro-optic light modulation elements in accordance with image signals from an original image.

However, the electro-optic light modulating element used in such conventional methods has a large effect on ambient temperature changes, so when actually used, it is difficult to use the
As described in the publication, it requires a temperature control device, which makes the device itself large, and in addition, in order to completely modulate each light beam, that is, control ON and OFF of each light beam, There were also problems with the single circuit configuration, such as the need to apply a bias voltage to the electro-optic modulation element.

Furthermore, the optical piece splitting devices used in the conventional methods have their own drawbacks. In other words, the above-mentioned
The light beam splitting device disclosed in Japanese Patent No. 33523 is composed of a half mirror and a combination of mirrors, but since the light beam passes through the half mirrors in order and splits the light beam, each There is a problem that the intensity of the light beams is not uniform.
The light beam splitting device used in the 02 publication etc. is as follows:
Increasing the number of light beams to be divided requires a larger one, and the larger the Wako beam, the greater the parallelism between the Wako beam entrance surface and the exit surface, which also increases manufacturing costs. .

Therefore, the present invention provides an image scanning recording device that eliminates these drawbacks. In particular, this device employs a light beam flattener to flatten the light beam incident on the acousto-optic modulation element. At the same time, this flat light beam is made incident on an acousto-optic modulation element having a plurality of ultrasonic excitation portions arranged on a single acousto-optic medium, and is emitted from the light modulation element. The light beam of the book is reduced to a predetermined magnification by an imaging lens system to form an array of minute light spots on a recording material, thereby recording a halftone image: an image scanning recording device according to the present invention. So, conventionally,
It has the great advantage (i) of eliminating the need for a light beam splitting means, which was indispensable in this type of device.

This will be explained based on the embodiment shown in FIG.
The original image cylinder 01) connected to the axis 0η of the recording cylinder (12) is rotated at an appropriate speed together with the recording cylinder (depressor), and at the same time, the feed screw (image cylinder 01) is rotated by the motor (181) via the reducer (19). ) is rotated,
The recording head 04) and the scanning head (13) are sent in the direction of the cylinder axis at an appropriate speed, and the scanning head (13) photoelectrically scans the original picture mounted on the original picture cylinder (11), thereby generating an image signal. is obtained. The image signal is then subjected to color correction and gradation correction in a color calculation circuit (21) in order to be reproduced and recorded as a proper printed matter, as in a general color scanner, and is converted into a dot as a corrected image signal. Sent to the formation circuit (b). In this dot forming circuit (a), a halftone dot forming signal is formed based on the pulse signal generated by the pulse generator (24) in response to the signal from the rotary encoder 06) and the image signal. The halftone dot formation signal is input to the recording head circle via the drive circuit (23), and a halftone image is recorded on the film on the recording cylinder 2 by controlling each light beam from the recording head 0Φ. Although the configuration of the color scanner shown in FIG. 1 is greatly simplified for ease of explanation, the apparatus according to the present invention is not only applicable to such a configuration.

FIG. 2 shows an embodiment of the image scanning and recording apparatus according to the present invention, in which (24J is a light source such as a laser, etc., and a pair of cylindrical lenses 125) is a light beam flat former formed by K+; 28) is an acousto-optic light modulator in which a plurality of ultrasonic excitation parts are arranged in parallel on a single acousto-optic medium. This is an imaging lens system for reducing and projecting onto the film (3ω) on the recording cylinder at a predetermined magnification.

Such an image scanning recording device is built in the recording head 0Φ shown in FIG. The light beams applied to the ultrasonic excitation portion and incident on the ultrasonic excitation portion are each independently exposed to O.
It is configured to perform N and OFF control.

Therefore, a light beam whose cross-sectional shape is approximately circular is emitted from a light source (goods) by a pair of cylindrical lenses (5) arranged so that their focal axes are spatially common and the focal position is shared. The light beam enters the light beam flattener □□□, which is made up of a company known as Co., Ltd., and is converted into a flat light beam that fits the incident surface of the subsequent acousto-optic light modulator ■, which then enters the light modulator ■. Ru. Among the flat light beams incident on the light modulation element (support), the light beams incident on the acousto-optic medium at positions corresponding to each ultrasonic excitation part were created using the dot forming circuit shown in Figure 1. The modulated light beams are modulated by ultrasonic signals emitted from each ultrasonic excitation part in accordance with the halftone dot forming signal, and a plurality of modulated light beams are emitted from the light modulation element as first-order light and zero-order light. On the other hand, since the light beam incident on a position of the acousto-optic medium that does not correspond to each ultrasonic excitation part passes through the acousto-optic medium as it is, here, the light beams that are modulated according to the halftone dot forming signal are Only the primary light, which is the light beam of the book, is projected onto the recording cylinder (the film one above) at a predetermined reduction magnification using the subsequent imaging lens system to form a fine light spot array. It is designed to copy and record images. Also, as another embodiment of the light beam flat former, a pair of cylindrical lenses (2), one of which is a single concave cylindrical lens, may be used. .

FIG. 3 shows another embodiment of the image scanning recording device according to the present invention, and this embodiment is particularly effective when the light source (24) and the acousto-optic light modulation element are arranged separately. o(311h Jin-A extract';y't:r
, O.

In summary, the present invention modulates a light beam with an acousto-optic light modulation element according to an image signal, thereby flattening the light source and the light beam from the light source when duplicating and recording a halftone image or the like. In order to divide the flat light beam into a plurality of light beams with incident diameters, the light modulation element includes a plurality of ultrasonic excitation parts that independently modulate each light beam by +2. Since this is an image scanning and recording device consisting of an acousto-optic light modulator and an imaging lens system arranged in parallel on one acousto-optic medium, it has the following effects.

■Since a light beam flattener is used, it is possible to split and modulate the light beam with a light modulation element without using a light beam splitter.In addition, the light beam flattener is more effective than a conventional light beam splitter. The components are simple, and the device can be made smaller and less expensive.

■When a laser beam is used after passing through a light beam flattener, the parallelism of the light beam is usually several mrad for general laser beams, but on the other hand, if the magnification factor is α, it is several mrad / Since the parallelism is higher than that of α, it is possible to separate the light modulation element and the light beam flattener without losing much of the parallelism, resulting in a design in which only the light modulation element can be built into the recording head αa. Oa is smaller and lighter, which is convenient.

■Compared to the case where a light beam splitter is provided before the acousto-optic light modulator, special precision is required for the alignment of the light beam output and incidence between the light modulator and the light beam flattener. First, the utilization rate of the light beam can be increased.

■The problems of the prior art described in the objective section can be solved.

[Brief explanation of drawings]

FIG. 1 shows a device diagram of an embodiment of the invention, FIG. 2 a block diagram of an embodiment of the invention, and FIG. 3 a block diagram of another embodiment of the invention. 12...Recording cylinder 24...Light source 25.26...Cylindrical lens 27...Light beam flattener Patent attorney Yoshihiko Okabe

Claims (1)

[Claims] (1) When a light beam is modulated according to an image signal by an acousto-optic light modulation element to reproduce and record a halftone image, etc., a light source and a light beam that forms the light beam from the light source into a flat shape are used. A beam flattener and an acousto-optic light modulation element in which a plurality of ultrasonic excitation parts are arranged in parallel on one acousto-optic medium in order to modulate a part of the flat incident light beam according to an image signal. and an imaging lens system for creating a minute light spot array corresponding to the output light beam from the light modulation element. A beam expander is disposed in front of the optical beam flattening device 131 of the image scanning recording device according to claim 1, which is constituted by a pair of cylindrical lenses disposed so that the focal axis is common between the beam expander and the beam expander. An image scanning recording device according to claim 1 or 2.