JPS61103117A - Scanning type copying machine - Google Patents

Abstract

PURPOSE:To draw a color image at the recording part of recording paper, etc., without any color deviation by curving the recording part about the reflecting surface of a polygonal reflecting mirror as a center of curvature along an arc which has a radius equal to the distance from this center of curvature to a beam convergence position. CONSTITUTION:The recording paper 13 as the recording part is curved about the reflecting surface of the polygonal reflecting mirror 15 as the center of curvature along the arc which has the diameter equal to the distance R from this center of curvature to the beam convergence position. Therefore, the scanning speed of a converged light spot by beam scanning becomes equal as compared with the scanning speed of the polygonal reflecting mirror 5, and the light beam is focused on the recording paper 13 with an extremely small shift in minimum spot position in a scanning area, performing color recording. A condenser lens 12 allows only an on-axis beam to pass, so there is no limitation of a view angle, etc., and chromatic aberration on the axis is only compensated, so the lens shape is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention scans three-color beams modulated according to copy record information using a polyhedral reflecting mirror, and focuses the beams onto a recording section such as recording paper to produce color images. This invention relates to a scanning type copying device for recording pictures.

Configuration of conventional example and its problems As shown in Fig. 1, a conventional scanning type copying apparatus copies a norther beam from a laser light source 1 using a modulator 2 and modulates it according to self-recorded information, and converts this modulated beam into a beam. The expanded beam is expanded by the expander 3, and then reflected by the reflecting mirror 4 to be further expanded by the beam expander 3. The expanded beam is scanned by a certain angle by the rotating polyhedral reflecting mirror 5, and then is scanned at a constant speed. The light passes through a scanning lens 6 and is condensed onto a recording paper 8 using a reflecting mirror 7 for recording. However, since the constant velocity constant distortion lens 6 is disposed behind the polyhedral reflection mirror 5, color shift occurs due to the refractive index of the lens. Since a beam of three colors is input, color shift occurs for a three-color beam input such as a color image. For this reason, when performing color recording, three constant velocity scanning lenses 6 must be reinstalled, resulting in high cost. Furthermore, the constant velocity scanning lens 6 has a large condensed spot diameter, making it impossible to obtain high resolution. Furthermore, although an inkjet method or a thermal transfer method is currently used for color recording, both of these methods have a slow scanning speed and cannot provide high resolution.

Purpose of the Invention The present invention solves the above-mentioned conventional problems. It is possible to draw a color image on a recording section such as a recording paper without causing color shift, and also to reduce the diameter of the spot. It is an object of the present invention to provide a scanning type copying apparatus which can obtain high resolution and further reduce costs.

Structure of the Invention In order to achieve the above object, the present invention includes a three-color laser light source, a modulator that modulates the beam from each laser light source according to copy recording information, and a beam modulated by the modulator that expands the beam. A beam expander, a reflecting mirror and beam splitter that completely synthesizes the C7'i4 three color beams expanded by each beam expander, a condensing lens that receives the beams synthesized by this beam splitter, and a condensing lens that receives the beams synthesized by this beam splitter. and a polyhedral reflecting mirror that deflects the beam, and the recording section is configured to be curved on an arc whose center of curvature is the reflecting surface of the polyhedral reflecting mirror and whose radius is the distance from the center of curvature to the beam condensing position. DESCRIPTION OF ONE EXAMPLE OF A DISASTER FOR WHICH THEY ARE AVAILABLE Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 2 and 3, the laser light source 1 is
The laser beams from the valley laser light source 1 are arranged in three rows in parallel so that laser beams of color wavelengths can be transmitted. The resulting beam is expanded by beam expanders 3 arranged in three rows. The expanded beams are then each reflected by a reflecting mirror 4,
The beam is expanded by beam expanders 3 arranged in three rows. The beam expanded by the outer beam expander 3 is reflected inward by a reflecting mirror 4, and is sequentially combined with the beam expanded by the central and inner beam expanders 3 by a beam splitter 9. The combined beams are sequentially reflected by reflection mirrors 10, 11 and condensed by a condenser lens 12, and the condensed beams are scanned by a certain angle by a rotating polyhedral reflection mirror (deflector) 5. The recording paper 13, which is a recording section, is curved on an arc whose center of curvature is the reflective surface of the polyhedral reflective mirror 6, and whose radius is the distance R from the center of curvature to the beam focusing position. Therefore, the scanning speed of the focused spot due to beam scanning becomes constant in proportion to the scanning speed of the polyhedral reflecting mirror 5, and the light is focused on the recording paper 13 where the deviation of the minimum spot position depending on the scanning area is very small. , recorded in color. Since the condensing lens 12 allows only the axial beam to pass through, it is not limited by the angle of view, etc., and since it is only necessary to correct axial chromatic aberration, the lens shape can be simplified, and chromatic aberration of magnification can be corrected. If the diameter of the incident beam is changed from the diffraction limit, chromatic aberration of magnification can be eliminated.

Effects of the Invention As is clear from the above explanation, according to the scanning copying apparatus of the present invention, expanded beams of three colors are combined by a reflecting mirror and a beam splitter, and the combined beam is condensed by a condensing lens. This beam is scanned at a certain angle by a polyhedral reflection mirror, and recorded by condensing it onto a recording paper curved on an arc whose radius is the distance from the reflection surface of the polyhedral reflection mirror to the beam focusing position. ing. In this way, the condensed spot can be scanned at a constant velocity without using a constant velocity scanning lens, and the condensing lens is installed in front of the polyhedral reflection mirror, and this condensing lens has limitations such as the angle of view. By reducing spherical aberration, the diameters of the slots and grooves can be reduced. Therefore, it is possible to obtain a high-resolution recording in color without any deviation. Also, since a condensing lens is used, 111+'+I
It has the advantage of being able to focus three colors of light and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a conventional scanning copying apparatus, FIGS. 2 and 3 show an embodiment of the scanning copying apparatus of the present invention, FIG. 2 is a schematic perspective view, and FIG. 3 is a schematic plan view. It is. 1... Laser light source, 2... Modulator,
3... Beam expander, 6...
Multifaceted extension/reflection Hmi y - (m direction B), s... Beam splitter - 112... Condensing lens, 13
... Recording paper (recording section). Name of agent: Patent attorney Toshio Nakao and 1 other person')
1

Claims (1)

[Claims] A laser light source that sends out three color laser beams, a modulator that modulates the beam from each laser light source according to copy recording information, a beam expander that expands the beam modulated by this modulator, and each beam expander. Equipped with a reflecting mirror and a beam splitter that combine the expanded three-color beams, a condensing lens that condenses the beams combined by the beam splitter, and a polyhedral reflective mirror that deflects the beam from the condensing lens, A scanning type copying apparatus characterized in that the recording section is curved on an arc whose center of curvature is the reflecting surface of a polyhedral reflecting mirror and whose radius is the distance from the center of curvature to a beam condensing position.