JPH04356861A - Optical scanner and image reader/recorder - Google Patents

Abstract

PURPOSE:To miniaturize the optical scanner, which executes the two-dimensional scan of an object to be scanned by light beams, and to reduce the cost. CONSTITUTION:An oscillating stand 15 of a pulse stage 14 holds a rotary polygonal mirror 13 to unidirectionally deflect light beams 20, and this oscillating stand 15 is moved along a bent plane 16a. Thus, the polygonal mirror 10 is oscillated around an axis M adjacent to the incidental point of the light beams 20 to a mirror face 10a while being parallel to a face formed with the light beams 20 by the above-mentioned deflection.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to an optical scanning device in which a light beam is deflected by an oscillating or rotating mirror, and more particularly, to an optical scanning device that allows a surface to be scanned to be two-dimensionally scanned by a light beam. This invention relates to an optical scanning device. The present invention also relates to a device that uses this optical scanning device to read image information from a document and record the image information on a photosensitive material.

0002

[Prior Art] Conventionally, a light beam as a reading light is scanned two-dimensionally over a document, and light (reflected light, transmitted light, emitted light, etc.) from a portion of the document irradiated with the light beam is photoelectrically collected. Various optical scanning reading devices have been provided that detect and read image information recorded on a document. On the other hand, various optical scanning recording devices are also provided that record the image information on a photosensitive material by modulating a light beam as recording light based on image information and scanning the light beam two-dimensionally on the photosensitive material. has been done.

In such optical scanning reading devices and optical scanning recording devices, mechanical optical deflection devices such as rotating polygon mirrors and galvanometer mirrors have conventionally been used as optical scanning devices for two-dimensionally scanning a light beam. A combination of two optical deflectors such as an AOD (acousto-optic deflector) or an EOD (electro-optical deflector) for main scanning and sub-scanning, as well as such optical deflectors. Many systems have been used, such as one in which one is used for main scanning, and sub-scanning is performed by moving the object to be scanned relative to the deflected light beam.

On the other hand, an image reading/recording apparatus has also been proposed which combines the above-described optical scanning reading apparatus and optical scanning recording apparatus to reproduce and record an image read from a document onto a photosensitive material.

[0005]

[Problems to be Solved by the Invention] However, as mentioned above, optical scanning devices that use two optical deflectors or conventional optical scanning devices that combine one optical deflector and a means for moving the object to be scanned for sub-scanning Scanning devices have become large and expensive. Therefore, when such an optical scanning device is applied to the above-mentioned image reading and recording device, the image reading and recording device also becomes large and expensive.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide an optical scanning device that can be made compact and inexpensive.

Another object of the present invention is to provide an image reading and recording device that can be formed compactly and inexpensively.

[0008]

[Means for Solving the Problems] The optical scanning device according to the present invention moves one mirror in two directions to two-dimensionally reflect and deflect the light beam incident thereon. , ◆ A mirror that reflects the light beam, and ◆ A first drive that swings or rotates this mirror back and forth around a predetermined axis to deflect the light beam incident thereon and perform main scanning on the surface to be scanned. a second mechanism that swings the mirror around an axis passing near the light beam incident point, deflects the light beam, and sub-scans the surface to be scanned;
The invention is characterized in that it is comprised of a drive mechanism.

On the other hand, an image reading/recording device according to the present invention utilizes the above-mentioned optical scanning device according to the present invention, and has: ◆ a reading light source that emits a reading light beam; The reading light beam is reflected by the mirror and arranged to two-dimensionally scan the original to be read, and then the light from the part of the original that is irradiated with the reading light is detected and recorded on this original. a photoelectric detection means for obtaining an image signal carrying image information; and a recording light source disposed so as to emit a recording light beam, and the recording light beam is reflected by the mirror and scans the photosensitive material two-dimensionally. , ◆light modulation means for modulating the recording light beam based on the image signal.

0010

[Operation] When the mirror of the optical scanning device configured as described above is reciprocated or rotated by the first drive mechanism, the light beam reflected thereon is one-dimensional, similar to that of a general galvanometer mirror or rotating polygon mirror. to be biased towards Then, when this mirror is swung around the above-mentioned axis by the second drive mechanism, the light beam is deflected in a direction that intersects with the direction of the one-dimensional deflection. Therefore, if this light beam is irradiated onto the surface to be scanned, the light beam will travel on that surface in two directions.
It will now scan dimensionally.

Therefore, in the image reading and recording apparatus having the above configuration, the optical scanning device can scan the document two-dimensionally with the reading light beam, and can scan the photosensitive material two-dimensionally with the recording light beam. can do.

0012

Effects of the Invention As described above, the optical scanning device of the present invention enables two-dimensional scanning of a light beam by moving one mirror in two directions, so it is possible to perform optical scanning using two optical deflectors. Compared to conventional optical scanning devices that use a combination of one optical deflector and a sub-scanning moving means, the optical scanning device can be made smaller and cheaper.

Therefore, the image reading and recording apparatus of the present invention using such an optical scanning device can also be formed in a small size and at low cost.

[0014] In the optical scanning device of the present invention, the scanning locus on the surface to be scanned is relatively easily curved compared to the conventional optical scanning device described above. However, in the image reading/recording apparatus of the present invention, since such an optical scanning device is used for both image reading and image recording, the reading distortion and recording distortion due to the above-mentioned curvature are canceled out, and the resulting image is not recorded on the original. It becomes possible to accurately reproduce and record images that have previously been recorded.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on embodiments shown in the drawings.

FIGS. 1 and 2 show an optical scanning device 1 according to a first embodiment of the present invention. This optical scanning device 1 is
As an example, it has a general rotating polygon mirror 13 consisting of a polygon mirror 10 having six mirror surfaces 10a and a motor 12 that rotates the polygon mirror 10 around a rotation axis 11.

The motor 12 of this rotating polygon mirror 13 is fixed to a swinging table 15 of a pulse stage 14. This pulse stage 14 holds the rocking table 15 on a fixed table 16 having a curved surface 16a forming a part of a cylindrical surface, and rotates the rocking table 15 every time it receives one drive pulse. It is moved by minute pitches along the curved surface 16a.

The rotating polygon mirror 13 includes the rotation axis 11 in a plane perpendicular to the central axis M of curvature of the curved surface 16a, and the point where the light beam 20 is incident on the mirror surface 10a is on the central axis M of curvature. It is fixed to the rocking table 15 in a state where it is located at . Note that since the point of incidence of the light beam 20 changes slightly depending on the rotational position of the polygon mirror 10, the central axis of curvature M is made to pass through the average point of incidence.

The motor 12 of the rotating polygon mirror 13 is driven by a motor driver 18 of the drive circuit 17,
0 is continuously rotated at high speed in the direction of arrow A in FIG. On the other hand, the pulse stage 14 is the stage driver 1 of the drive circuit 17.
9 to swing the swing table 15 in the direction of arrow B in FIG. In this embodiment, the polygon mirror 10 is rotated by the motor 12 and its driver 18.
The pulse stage 14 and its driver 19 constitute a second drive mechanism that swings the polygon mirror 10. Note that one drive pulse is sent from the stage driver 19 to the pulse stage 14 every 1/6 rotation of the motor 12.

When the polygon mirror 10 rotates as described above, the light beam 20 incident on the mirror surface 10a is reflected and deflected there, and scans the surface to be scanned 21 in the direction of arrow X (main scan). Furthermore, each time this main scanning is performed, the swing table 15, that is, the polygon mirror 10 swings one pitch at a time about the central axis M of curvature as the swing axis, so that the light beam 20 is deflected in the direction of the arrow Y. Here, since the relationship between the rotation axis 11 and the swing axis M of the polygon mirror 10 is as described above, the deflection in the direction of the arrow Y is the plane formed by the light beam 20 deflected by the rotation of the polygon mirror 10. (shown with diagonal lines in FIG. 2) is allowed to swing about axis M. Therefore, the light beam 20 sub-scans the surface to be scanned 21 in a direction substantially perpendicular to the main scanning direction X, and two-dimensional scanning by the light beam 20 is realized.

Next, an optical scanning device 2 according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. Note that in FIGS. 3 and 4, elements that are equivalent to those already described are given the same numbers, and redundant explanations thereof will be omitted.

In the second embodiment, a galvanometer mirror 30 is used in place of the rotating polygon mirror 13 of the first embodiment. This galvanometer mirror 30 is also a general one, and includes a plate-shaped mirror 31 and a galvanometer 33 that swings the mirror 31 back and forth around a swing shaft 32 (in the direction of arrow C). In the galvanometer mirror 30, the swing axis 32 is included in a plane perpendicular to the central axis of curvature M of the curved surface 16a, and the point at which the light beam 20 is incident on the mirror surface 31a (average incident point) is located within the curved surface 16a. It is arranged so as to be located on the central axis M. Note that the galvanometer 33 is driven by a galvanometer driver 18' of the drive circuit 17.

In this optical scanning device 2 as well, the light beam 20 incident on the mirror 31 of the galvanometer mirror 30 is directed to the surface to be scanned 21 by the mirror 31 swinging back and forth.
The scanning table 15 of the pulse stage 14 swings and the mirror 31 is gradually tilted, thereby scanning the scanning surface 21 in the main scanning direction X. Sub-scanning is performed in the almost perpendicular arrow Y direction.

Next, an embodiment of the image reading and recording apparatus of the present invention will be described with reference to FIG. For example, this device reads a radiation image stored and recorded on a stimulable phosphor sheet 40 as shown in Japanese Patent Application Laid-Open No. 57-76974, and transfers the read radiation image to a photosensitive material 40.
It is configured to be recorded as a photographic latent image. In this example, the stimulable phosphor sheet 40 is particularly one in which a stimulable phosphor layer is formed on a transparent sheet-like support. This stimulable phosphor sheet 40 stores and records a radiation image of the subject by irradiating the subject with radiation that has passed through the subject.

First, when reading a radiation image, the stimulable phosphor sheet 40 is transported by a transport means comprising a plurality of pairs of nip rollers 42 and the like, and placed at a predetermined position (the position shown in the figure). A laser beam 44 emitted from the laser light source 43 is transmitted to an AOM (acousto-optic modulator) 4 which will be described later.
5 and enters the polygon mirror 10 of the optical scanning device 1. This optical scanning device 1 is shown in FIGS. 1 and 2. Also, at this time, the AOM 45 is deactivated.

The laser beam 44 is reflected and deflected by the optical scanning device 1, passes through the fθ lens 46, main-scans the stimulable phosphor sheet 40 as a reading document in the direction of arrow X, and then scans in the direction of arrow Y. Perform sub-scanning. In this way, the laser beam 4
From the part of the stimulable phosphor sheet 40 irradiated with 4,
Stimulated luminescence light 47 of an amount corresponding to the radiation image information stored and recorded therein is emitted. This stimulated luminescence light 47 is transmitted to a light receiving surface 48 facing the entire surface of the stimulable phosphor sheet 40.
is detected by a photomultiplier tube 48 with a.

The photomultiplier tube 48 outputs an analog image signal S indicating the amount of the stimulated luminescent light 47, that is, the radiation image information stored and recorded on the stimulable phosphor sheet 40. After this image signal S is amplified by an amplifier 49, it is sent to an A/D converter 50 where two of the laser beams 44 are
It is sampled and quantized at timing synchronized with the dimensional scanning, and is made into a pixel-divided digital image signal Sd. This digital image signal Sd undergoes image processing (signal processing) such as gradation processing and frequency processing in the image processing device 51 and is then temporarily stored in the image memory 52.

The stimulable phosphor sheet 40 is prepared as described above.
When the radiation image reading from the nip roller 4 is completed, the nip roller 4
The second transport means is operated again and the stimulable phosphor sheet 4
0 is ejected from the position shown in FIG. 5, and a photosensitive material 41 is placed in its place. Next, the laser light source 43 and the optical scanning device 1 are activated, and the laser light 44 two-dimensionally scans the photosensitive material 41 in the same manner as in the previous case. At this time, the image signal Sd read from the image memory 52 is converted into an analog signal by the D/A converter 53 and then sent to the modulation circuit 54. The AO driven by this modulation circuit 54
M45 modulates the laser beam 44 based on the image signal Sd. As a result, the image carried by this image signal Sd, that is, the radiation image recorded on the stimulable phosphor sheet 40, is recorded on the photosensitive material 41 as a photographic latent image.

When image recording is completed as described above,
The photosensitive material 41 is transferred by a transfer means such as a nip roller 42,
It is discharged from the position where it is scanned by the laser beam 44. The photosensitive material 41 is then sent to a known developing device (not shown) and subjected to development processing, so that the photographic latent image recorded thereon is visualized.

The case where the radiation image read from the stimulable phosphor sheet 40 is immediately reproduced and recorded on the photosensitive material 41 has been described above.
are successively subjected to reading processing, and each image signal Sd for several images obtained thereby is stored in the image memory 52, and each radiation image carried by these image signals Sd is sequentially reproduced and recorded on the photosensitive material 41. You may also do so.

Further, in the above embodiment, the laser light source 43 is used as both the reading light source and the recording light source, but it is also possible to use separate reading and recording light sources.

Furthermore, instead of the photomultiplier tube 48, a CCD image pickup device or the like having its own pixel division function may be used. Furthermore, instead of a photodetector having a large light-receiving surface facing the recording surface of the stimulable phosphor sheet 40, it has a light-incidence end surface as large as this light-receiving surface, and is gradually narrowed down from there to emit relatively small light. A light guide having a shape continuous to the end surface and a photodetector having a relatively small light receiving surface optically coupled to the light emitting end surface may be used.

3 and 4 instead of the optical scanning device 1.
It is also possible to use the optical scanning device 2 shown in FIG.

The optical scanning device according to the present invention can of course be used in image reading and recording devices other than the above-mentioned image reading and recording devices, such as image reading and recording devices. If used, the curvature of the scanning locus on the original and on the photosensitive material will be offset as described above, which is particularly preferable. Note that there are various uses of this type of image reading device or image recording device in which the curvature of the scanning locus does not pose a problem. Further, it is also possible to almost eliminate the curvature of the scanning locus by placing the original or photosensitive material to be scanned by the light beam on a curved platen.

[Brief explanation of the drawing]

FIG. 1 is a side view of an optical scanning device according to a first embodiment of the present invention.

FIG. 2 is a plan view of the optical scanning device of the first embodiment.

[Figure 3]
A side view of an optical scanning device according to a second embodiment of the present invention

[Figure 4]
A plan view of the optical scanning device of the second embodiment

FIG. 5 is a schematic perspective view showing an embodiment of the image reading and recording device of the present invention.

[Explanation of symbols]

1, 2 Optical scanning device 10 Polygon mirror 10a, 31a Mirror surface 11 Polygon mirror rotation axis 12 Motor 13 Rotating polygon mirror 14 Pulse stage 15 Rocking table 16 Fixed table 18 Motor driver 18' Galvanometer driver 19 Pulse stage driver 20 Light beam 21 Surface to be scanned 30 Galvanometer mirror 31 Mirror 32 Mirror swing axis 33 Galvanometer 40 Stimulative phosphor sheet 41 Photosensitive material 43 Laser light source 44 Laser light 45 AOM 47 Stimulated luminescence light 48 Photomultiplier tube 49 Amplifier 50 A/D conversion device 52 memory 53 D/A converter 54 modulation circuit

Claims (2)

[Claims] Claim 1: A mirror that reflects a light beam, and a mirror that is reciprocated or rotated about a predetermined axis,
a first drive mechanism that deflects the light beam incident thereon to perform main scanning on the surface to be scanned; and a first drive mechanism that deflects the light beam by swinging the mirror around an axis passing near the light beam incident point. and the second sub-scanning on the surface to be scanned.
An optical scanning device consisting of a drive mechanism. 2. A reading light source that emits a reading light beam, and this reading light beam is reflected by the mirror and passes over the original to be read.
The optical scanning device according to claim 1, which is arranged to scan dimensionally, and the light from the reading light irradiated portion of the document is detected to obtain an image signal carrying image information recorded on the document. a photoelectric detection means; a recording light source disposed so as to emit a recording light beam, and the recording light beam is reflected by the mirror to two-dimensionally scan the photosensitive material; An image reading/recording device comprising a light modulating means that modulates the image based on the image.