JPH0397364A - Picture scanning recorder - Google Patents

Abstract

PURPOSE:To provide an image forming lens to a position close to a photosensing material independently of the size of the photosensing material by applying scanning exposure while an exposure head is driven in a plane in parallel with a flat photosensing material such as a glass dryplate. CONSTITUTION:An exposure head 4 is provided with a cylinder 4a whose shaft center is perpendicular to a table face and a hollow arm 4b linked to a lower end of the cylinder 4a horizontally, and plural light beams LB modulated by an optical modulator 7 are made incident in the exposure head 4 along the shaft center of the cylinder 4a. The light beam LB reflected in a 2nd reflecting face 4e is formed onto a face of a photosensing material via an image forming lens 4f provided to the lower face of the tip of the arm 4b. Thus, each small region being division of the photosensing material face is subject to line sequential scanning exposure with a circular-arm scanning line to allow a required pattern to be exposure-recorded onto the face of the photosensing material.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to image scanning in which a photosensitive material is scanned and exposed with a light beam modulated and controlled by an image signal based on a desired pattern to record an image of the pattern. In particular, it relates to a recording device, in which an exposure head that performs scanning exposure is rotated in a plane parallel to the surface of a flat photosensitive material, and the photosensitive material is sent in a sub-scanning direction along that plane. This invention relates to an image scanning recording device that performs line-sequential scanning exposure using scanning lines.
BACKGROUND TECHNOLOGY Conventionally, as an image scanning recording device such as a color scanner for plate making, there has been a drum scanning type recording device as described in Japanese Patent Application Laid-Open No. 62-232611,
A light beam deflection type recording device as described in Japanese Patent No. 90614 is known. A drum scanning type recording device rotates a rotating drum on which a photosensitive material is mounted, and moves an exposure head in the axial direction of the drum to perform line-sequential scanning exposure. On the other hand, a light beam deflection type recording device attaches a photosensitive material to the surface of a conveying table and transports it, while the light beam is deflected by a corner moving mirror or rotating polygon mirror and projected onto the photosensitive material. Scanning exposure is performed sequentially. <Problems to be Solved by the Invention> However, in the case of conventional examples having such a precept, each of them has the following problems.

In other words, a drum scanning type recording device can perform scanning exposure with the imaging lens of the exposure head close to the drum surface (photosensitive material), so the light beam diameter can be narrowed down and high precision can be achieved. However, on the other hand, the photosensitive material is limited to flexible photographic film that can be attached to a drum, and hard flat photosensitive materials such as glass dry plates cannot be used. There is a problem.

On the other hand, a light beam deflection type recording device can perform scanning exposure using a flat, hard photosensitive material, which is advantageous in terms of dimensional stability, but has the problem that it is difficult to focus the light beam into a small size. ．． That is, the diffraction limit, which is the limit of convergence of a light beam such as a laser, is determined by the N, A. (Nus+erical Ap
The larger the numerical aperture (numerical aperture), the smaller the diameter can be focused. However, in light beam deflection type devices, due to structural constraints, the distance between the imaging lens and the photosensitive material is proportional to the size of the photosensitive material. N.
A. In order to increase the size by 1, a lens with an extremely large diameter would be required, which is not realistic. For this reason, the optical beam deflection type device can only narrow down the optical beam diameter to a certain extent, and is not suitable for recording precise patterns with high definition. The present invention has been made in view of the above circumstances, and provides an image scanning recording device that can scan and expose high-definition images at high speed using a planar photosensitive material. The purpose is to

Means for Solving the Problem> The present invention takes the following precautions in order to achieve the above object. That is, the present invention provides an image scanning recording apparatus that sequentially scans and exposes a planar photosensitive material in each divided area using arcuate scanning lines, which comprises: a table on which the photosensitive material is mounted; sub-scan feeding means for sub-scanning the table in two orthogonal axes directions within the table surface; an exposure head rotatably driven in a plane parallel to the table surface; a position detection means for detecting the scanning position of the light beam based on the rotation angle; an image output control means for outputting image data corresponding to the position based on the position data from the position detection means; and a light source for generating the light beam. a light beam modulator for modulating the light beam irradiated from the light source based on image data from the image output control means; and a light beam modulator for imaging the light beam modulated by the light beam modulator on a photosensitive material surface. a first sub-scanning feed mechanism that includes an image lens, and the sub-scanning feeding means feeds the table intermittently or continuously in a first sub-scanning direction in relation to arcuate main scanning by the exposure head; a second sub-scanning feed mechanism that intermittently moves the table in a second sub-scanning direction perpendicular to the first sub-scanning feed in a width smaller than the rotation radius of the exposure head; a first reflecting section that receives a light beam modulated by the light beam modulating means along the center of the rotation axis and reflects the incident light beam in the direction of the rotation radius; and reflects the reflected light beam toward the table surface. Second to do
and a rotation drive unit that integrally rotates the first reflection unit and the second reflection unit. <Operation> The operation of the present invention is as follows. The light beam irradiated from the light source is incident on the exposure head along the center of its rotation axis via the light beam modulation means.

The incident light beam is reflected in the rotational radial direction by the first reflecting section, further reflected toward the table surface by the second reflecting section, and then imaged on the photosensitive material surface. On the other hand, the table on which the photosensitive material is mounted is intermittently or continuously fed in the first sub-scanning feed direction by the first sub-scanning feed mechanism in conjunction with the circular arc-shaped main scanning by the exposure head. A rectangular area on the material surface in the first sub-scanning direction is sequentially scanned and exposed using arc-shaped scanning lines. When the rectangular area is scanned and exposed, the table is intermittently fed by a second sub-scanning feed mechanism in a second sub-scanning direction perpendicular to the first sub-scanning direction at a width smaller than the rotation radius of the exposure head. be done.

Then, in the same manner as above, in connection with the arc-shaped main scan by the exposure head, the table is sub-scanned in the first sub-scanning direction, so that the rectangular area is line-sequentially scanned in the arc-shaped scanning line. Scanning exposure is performed.

The position detection means detects the scanning position of the light beam based on the first and second sub-scan feeding positions of the table and the rotation angle of the exposure head. The image output control means outputs image data corresponding to this position data to the light beam modulation means. The light beam modulator modulates the light beam emitted from the light source based on the image data.

As described above, each of the divided small areas on the surface of the photosensitive material is sequentially scanned and exposed using arcuate scanning lines, whereby a desired pattern is exposed and recorded on the surface of the photosensitive material. <Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is an external perspective view showing a schematic structure of an image scanning and recording apparatus according to this embodiment, and FIG. 2 is a block diagram showing a schematic structure of a control system.

Please refer to FIG. In the figure, reference numeral 1 denotes a table on which a flat photosensitive material A such as a glass dry plate is mounted. The table 1 is sub-scan fed in the orthogonal 2IJIi direction within the table surface by a first sub-scan feed mechanism 2 and a second sub-scan feed mechanism 3 as sub-scan feed means. The first sub-scanning feed mechanism 2 includes a guide 2a that slidably supports the table l in the first sub-scanning direction (X direction);
It consists of a screw shaft 2b screwed onto the table 1, a motor 2C driving the screw shaft 2b, and a movable base plate 2d supporting the guide 2a and the motor 2c. The second sub-scanning feed mechanism 3 includes a guide 3a that slidably supports the table l in a second sub-scanning direction (Y direction) via a movable base plate 2d, and a screw shaft that is screwed into the movable base plate 2d. 3b, a motor 3c that drives the screw shaft 3b, and a base plate 3d that supports the guide 3a and the motor 3c.

Reference numeral 4 denotes an exposure head that is rotationally driven in a plane parallel to the table l. The exposure head 4 includes a cylindrical portion 4a having an axis perpendicular to the table surface, and a hollow arm portion 4b horizontally connected to the lower end of the cylindrical portion 4a. It is rotatably supported by a body 4i (see FIG. 2).

A plurality of light beams LB modulated by an optical modulator 7, which will be described later.
enters the exposure head 4 along the axis of the cylindrical portion 4a.

The arm portion 4b of the exposure head 4 includes a rhomboid prism 4c.
is provided. The rhomboid prism 4c has a first reflecting surface 4d that reflects the light beam LB incident on the exposure head 4 in the rotation radius direction, and reflects the light beam LB reflected by the reflecting surface 4d toward the table surface. A second reflective surface 4e is provided. The light beam LB reflected by the second reflective surface 4e is imaged on the photosensitive material surface via an imaging lens 4f provided on the lower surface of the tip of the arm portion 4b. Arm portion 4b
A weight 4h is attached to the other end to maintain balance during rotation. Further, a direct drive motor 4g serving as a rotational drive unit is connected to the cylindrical portion 4a, and the direct drive motor 4g causes the cylindrical portion 4 to rotate.
The rhomboid prism 4c, the imaging lens 41, etc. are rotated integrally by rotating the arm 4b and the rhomboid prism 4c. Reference numeral 5 denotes a light source that generates a light beam such as a laser beam, and the light beam emitted from the light source 5 is split into a plurality of parallel light beams LB by a multi-type beam splitter 6. Each divided light beam LB is transmitted through an electro-optic light modulator (E○M:
Electro-Optic-Modulator)
7 and are subjected to ON/OFF modulation by respective required image signals (dot data). The light beam LB modulated by the electro-optic light modulator 7 is incident along the axis of the cylindrical portion 4a of the exposure head 4 via a lens 8 and a reflection mirror 9. The lens 8 and the imaging lens 4f of the exposure head 4 are arranged in an afocal arrangement. The exposure head 4 is attached with a rotary encoder 10a for detecting its rotation angle.

Further, as shown in FIG. 2, the l-th sub-scanning feed mechanism 2 includes a linear encoder 10b for detecting the position of the table I in the X-axis direction, and the second sub-scanning feed mechanism 3 includes a table IOY. A linear encoder 10c for detecting the position in the axial direction is attached to each. The detection signal of the rotary encoder 10a is sent to the main scanning feed control circuit 11a, the detection signal of the linear encoder tab is sent to the sub-scanning X-axis feed control circuit 1lb, and the detection signal of the linear encoder 10c is sent to the sub-scanning Y-axis feed control circuit. 1
1c to the scan control circuit 12, respectively. The scanning control circuit 12 calculates momentary position data of the irradiation point of the light beam LB based on each detection signal, and outputs the position data to a raster image processor (RTP) 14 as an image output control means. The scan control circuit 12 sets the rotation speed (main scan feed speed) of the exposure head 4 for the main scan feed control circuit 11a, and the main scan feed control circuit 11a uses direct drive to maintain the rotation speed. Drive and control motor 4g. The scanning control circuit 12 also includes a sub-scanning X-axis feed control circuit 1l.
For b, the intermittent feed pitch of the table 1 in the X-axis direction is specified, and the sub-scanning X-axis feed control circuit 1lb drives and controls the motor 2C so as to achieve the feed pitch. Furthermore, the scan control circuit 12 specifies the intermittent feed pitch of the table l in the Y-axis direction to the sub-scan Y-axis feed control circuit 11c, and the sub-scan Y-axis feed control circuit 11c adjusts the feed pitch to the sub-scan Y-axis feed control circuit 11c. Drive control of motor 3C. At this time, the intermittent feed pitch in the Y-axis direction is set to be smaller than the rotation radius of the exposure head 4. Reference numeral 13 is a minicomputer that converts CAD data of a drawing pattern into contour side vector data. CAD data of various drawing patterns are stored on the magnetic disk 15 or magnetic tape 16, and the CAD data of the desired drawing pattern is taken into the ξnicomputer 13 by designation from the console 17. The contour side vector data created by the computer 13 is given to the raster image processor 14. Based on the contour side vector data given from the minicomputer 13, the raster image processor 14
It generates dot data for ON/OFF control of the light beam, and outputs dot data corresponding to the position data given from the scanning control circuit 12 to each channel of the electro-optic light modulator 7. Note that detailed image processing by the above-mentioned minicomputer 13 and raster image processor 14 will be described later.

In an image scanning recording device equipped with the above configuration,
Photosensitive material A is scanned and exposed line-by-line using arc-shaped scanning lines as follows. Please refer to Figure 3 below. Area AI in the figure is a divided rectangular area on the surface of the photosensitive material that is to be scanned and exposed line-sequentially using circular arc-shaped scanning lines. This is preset as the pitch of intermittent feed. In the figure, symbol B indicates the rotation locus of the exposure head 4. Now, when scanning exposure is proceeding in the X direction, the table 1 is in a stopped state while the exposure head 4 is passing through at least the part shown by the solid line in the rotation locus within the area A1, and the table 1 is in a stopped state. Sometimes, arc-shaped scanning exposure is performed using a plurality of optically modulated light beams LB. By the way, when a plurality of light beams LB pass through the cylindrical portion 4a of the exposure head 4, if the light beams LB are arranged in the X direction, the light spot array projected onto the photosensitive material A will also be 3
They are arranged in the X direction as shown in the figure. The direction of this light spot array is always parallel to the X direction regardless of the rotation angle of the arm 4b of the exposure head 4, and the pitch of the light spot array does not change. The width Wx in the X-axis direction of the area exposed by the light spot array becomes constant. As shown in FIG. 3, there is no problem if the area AlO width WV is relatively small compared to the rotational diameter of the exposure head 4, but if the width Wv is close to the rotational diameter of the exposure head 4, In particular, at both ends of area A1, the traveling direction of the light spot array is at a large angle with respect to the direction perpendicular to the light spot array.
The trajectory of each light spot will partially overlap its neighbors.

To prevent the trajectories of the light spots from overlapping, the exposure head 4
By changing the voltage applied to the electro-optic light modulator 7 according to the rotation angle of the arm 4b of the
This can be handled by continuously changing the intensity of the exposure head (lowering the intensity at both ends of area A and increasing it at the center). 4 is passing through the path indicated by the broken line of the rotation locus, the first sub-scanning feed mechanism 2 is driven, and the table 1 is intermittently moved in the X-axis direction by a distance W1 corresponding to the number of light beams LB. The scanning exposure in an arc shape similar to that described above is performed. Note that the intermittent feeding of the table l does not necessarily have to be performed every one rotation of the exposure head 4; for example, every two rotations of the exposure head 4. That is, during the first rotation of the exposure head 4, scanning exposure may be performed with the table 1 in a stopped state, and during the second rotation of the exposure head 4, the table 1 may be moved intermittently.The above operation may be repeated. When the area AI is line-sequentially scanned by arc-shaped scanning lines, the second sub-scanning feed mechanism 3 is intermittently fed by a distance W in the Y-axis direction in order to scan and expose the adjacent divided area A2. Then, while the table 1 is intermittently fed in the opposite direction to the area A1 by the first sub-scanning feed mechanism 2, the area A2 is sequentially scanned and exposed using arcuate scanning lines. Figure 4(a) shows how each area is exposed back and forth in the X-axis direction in this way.The way the exposure progresses in the X-axis direction is limited to the above-mentioned back and forth exposure. Alternatively, as shown in FIG. 4(b), exposure may be carried out from one direction. The table 1 is moved by a required pitch within a required period (non-exposure period) during the rotation period of the exposure head 4, and A complicated sub-scanning feed control is required to ensure that the table 1 remains at a fixed position. Therefore, if the main scanning is performed while the table 1 is continuously moved at a constant speed in the X-axis direction, the sub-scanning in the X-axis direction is The feed control becomes easier, but in this case, the light beam L
Since the table 1 moves in the X-axis direction during the period in which the photosensitive material B is scanned and exposed, distortion occurs in the scanning locus. FIG. 5 is a schematic diagram showing the distortion of this scanning trajectory. When the photosensitive material A is stationary, the trajectory of the light spot array of the light beam LB is centered around the rotation axis of the exposure head 4, as shown by the broken line C. ○
However, if the photosensitive material A is continuously fed in the sub-scanning direction in the X-axis direction, the trajectory will be as shown by the solid line D, resulting in a deviation of "δ" in the X direction. The amount of movement of table 1 in the X direction in l main scanning period is W
X (corresponding to the width of the light spot array of the light beam LB), and with the starting point E of the scanning trajectory as the reference position, the arm 4 of the exposure head 4
If the rotation angle of b is ``α'', the amount of the above-mentioned deviation δ can be found by the following proportional expression. 360'': WX α: δ .゛． δ=W,!・α/360
(1) That is, when the table 1 is continuously fed in sub-scanning in the X direction, the light spot array reaches the starting point of the scanning recording area of the photosensitive material A during each scanning period. From this time, the projection position of each light beam LB is changed in the direction opposite to the first sub-scanning direction by the amount of "δ" determined by equation 11, relative to the rotation angle "αJ" of the arm portion 4b. If you shift it to
The scanning trajectory coincides with the broken line C, and the deviation "δJ" caused by the continuous drive of the table l is corrected, making it possible to record a duplicate image without distortion. Light modulator 7 and lens 8
A beam shifter 18 equipped with a transparent plate whose front and back sides are parallel planes is inserted into the optical path between the optical axis of the light beam LB, and a control signal is given from the scanning control circuit 12 to the beam shifter control section 19. The light beam is shifted by changing the oblique angle of the plate. FIG. 7 is a perspective view showing an example of the configuration of the beam shifter l8,
A transparent plate 18a whose front and back surfaces are parallel is attached and fixed to the swing shaft of the galvanometer 18b, and the beam shifter control unit l
A galvanometer 18b is driven by a control signal from 9 to control the inclination angle of the transparent plate 18a.

FIG. 8 is a diagram for explaining the function of the beam shifter 18 described above. The thickness of the transparent plate 18a is "t", the refractive index is "n", the modulus vAN of the transparent plate 18a and the incident light beam LB.
Assuming that the angle with respect to I is "θ,", the shift amount "L" of the light beams L and B2 transmitted through the transparent plate 18a can be obtained by the following equation (2). L=t(1-cos θ+/n sin#complete) s
in θ1...(2) This "LJ value is the deviation due to continuous feed of table 1"
(However, when the light beam LB is reduced and projected by the lens 8 and the imaging lens 4f, the amount is adjusted to match L - δ/r (1/r is the magnification). ), the distortion caused by the deviation "δ" can be corrected by driving and controlling the galvanometer 18b in synchronization with the arm 4b of the exposure head 4 and periodically swinging the transparent plate 18a to a required angle. It is possible to record a duplicate image. This embodiment uses the structure explained in the second embodiment as a means for shifting the light spot array of the light beam LB in order to correct the shift in the scanning locus caused by continuously feeding the table l. This is an image recording device having a different configuration.

As shown in FIG. 9, in the apparatus according to the present embodiment, the rhomboid prism 4c provided in the apparatuses of the first and second embodiments is replaced by a rhomboid prism 4c that is arranged along the rotational axis of the exposure head 4. a reflection mirror 20 as a first reflection part that reflects the light beam LB incident thereon in the direction of the rotation radius, and a second reflection part that reflects the light beam LB reflected by the reflection mirror 20 toward the table surface. The reflecting mirror 21 is connected to a galvanometer 22 as described in FIG. 7 so as to be swingable. The galvanometer 22 is driven by a control signal manually inputted from the scanning control circuit 12 via the galvanometer mirror driver 23.
It swings at a required angle in synchronization with the rotation of the arm portion 4b of the exposure head 4 to shift the position of the projection point of the light beam LB onto the photosensitive material A in the X-axis direction.

By controlling the galvanometer 22 so that the amount of shift of this projection point matches the amount of deviation "δ" based on the movement of table l, the deviation "δJ" is corrected and a duplicate image without distortion is produced. This embodiment automatically adjusts the focus of the optical system of the exposure head 4 in response to changes in the thickness of the photosensitive material A mounted on the table 1. have the means to do so.

See Figure 10. A screw shaft 24 is screwed into a frame 41 that rotatably supports the n-optical head 4.
The exposure head 4 is raised and lowered by driving a motor 25 connected to the motor 25. In this embodiment, the lens 8 is built into the exposure head 4 so that it moves up and down together with the exposure head 4. The height of the n-optical head 4 is detected by a linear encoder 26, and its detection signal is given to the scan control circuit l2 via a focus control circuit 27. The scan control circuit 12 sets the initial value of the height of the exposure head 4 to the focus control circuit 27 according to the thickness of the photosensitive material A and the like. When starting exposure, the focus control circuit 27 drives the motor 25 to adjust the height of the exposure head 4 to match the set initial value, and during exposure, the focus control circuit 27 adjusts the height of the exposure head 4 to match the set initial value. The height of the exposure head 4 is automatically controlled based on the focus detection signal. The focus detection unit 28 includes a focus detection light source 2 that is not sensitive to the photosensitive material A at a wavelength different from that of the exposure light source 5.
It has 9. Light beam LB irradiated from light source 29
' enters the dichroic prism 32 provided on the optical path between the electro-optic modulator 7 and the reflection ξ mirror 9 via the reflection mirror 30 and the cube beam splitter 31. The light beam LB' incident on the dichroic prism 32 is reflected along the optical path of the exposure light beam LB, enters the exposure head 4, and is projected onto the photosensitive material A together with the exposure light beam LB.

The light beams LB and LB' reflected by the surface of the photosensitive material A return along the optical path of the exposure head 4 and enter the dichroic prism 32. The dichroic prism 32 selectively reflects only the focus adjustment light beam LB' among the incident light beams LB and LB'. The reflected light beam LB' is reflected by a cube beam splitter 31 and then enters a four-split photodiode 34 via a cylindrical lens 33. As shown in FIG. 11(a), photodiodes 34a and 34c among the four-divided photodiodes 34
is given to the differential amplifier 35 as a positive input, and the photodiodes 34b and 34d are given as negative inputs to the differential amplifier 35. The cylindrical lens 33 has its curvature axis aligned with the X direction shown in FIG. 11(a), and its non-curvature axis aligned with the y direction.
The light beam LB′ projected onto the four-split photodiode 34 via the cylindrical lens 33 is transmitted to the exposure head 4.
When the optical system of is in focus, Fig. 11(b)
As shown in the figure, the output signal of the differential amplifier 35 (
focus detection signal) becomes zero level. If the n-optical head 4 is too high, the amount of light incident on the photodiodes 34a and 34c increases as shown in FIG. 11(C), so that the output signal of the differential amplifier 35 shifts to a positive level, If the exposure head 4 is too low, the amount of light incident on the photodiodes 34b and 34d increases as shown in FIG. 11(d), and as a result, the output signal of the differential amplifier 35 shifts to a negative level.

FIG. 11(e) shows the level change of the focus detection signal corresponding to the height of the exposure head 4. When the focus detection signal as described above is given to the focus control circuit 27, the focus control circuit 27 adjusts the height of the exposure head 4 so that the focus detection signal becomes zero level, and as a result, the exposure head 4 is exposed to light. Depending on changes in the thickness of material A, etc., gA is adjusted to an optimal height, and scanning exposure is always performed in a focused state.

Ru.

(1) In the above-mentioned embodiment, the case where the imaging lens 4r was provided at the output end of the exposure head 4 was described, but when using a relatively small exposure head, the imaging lens 4r
It is also possible to provide f at a position other than the output end. That is, when the distance between the reflecting surfaces 4d and 4e of the rhomboid prism 4c is small, the imaging lens 4r may be placed above the reflecting surface 4d, and similarly, the reflecting surface in the embodiment of FIG. Kula 20. It is also possible to provide an imaging lens 4f between the lenses 21 and 21. Furthermore, if the direct drive motor 4g and rotary encoder 10a in the embodiment shown in FIG. (2) In the embodiment described in FIG. 1 etc., the reflecting surfaces 4d and 4e of the rhomboid prism 4C were used as optical means corresponding to the first reflecting section and the second reflecting section in the present invention, but these may be constructed using two reflecting mirrors or prisms. Further, as shown in FIG. 12, a disk-shaped glass material (or aluminum material) 36 has a reflecting surface 36a that reflects the incident light beam in the direction of the rotation radius, and a reflecting surface 36a that reflects the reflected light beam toward the table surface. It is also possible to use a hole with a reflective surface 36b. (3) In the present invention, the arm portion 4b of the exposure head 4 can be made relatively short because each divided area of the photosensitive material surface is scanned and exposed line-by-line using arcuate scanning lines. Therefore, the torque required for rotation is also reduced, so the exposure head 4
A 4g direct drive motor was used as the rotational drive unit. However, the rotational drive section of the exposure head 4 is not limited to this, and may be configured to be driven by a belt by a motor. Furthermore, an exposure head may be used in which a disc-shaped glass material is directly driven by a belt by a motor as shown in FIG. 12. As a modulation means, an electro-optic modulator 7 with excellent responsiveness is used in consideration of the high-speed rotation of the exposure head 4. However, when the exposure head 4 does not rotate at a very high speed, acousto-optic modulation is used. An AOM can also be used.

(5) Furthermore, in the second and third embodiments,
When the table 1 is continuously fed in sub-scanning directions in the X-axis direction, a galvanometer is used to shift the optical path of the light beam to correct the deviation "δ" due to continuous movement, which will be explained later. The deviation "δ" may be corrected by correcting the data when processing the image signal. (6) Furthermore, instead of the light source 5 and multi-type beam splitter 6 in each of the above embodiments, an arrayed semiconductor laser having a plurality of light emitting ends may be used. In this case, as is well known, since the semiconductor laser element itself has a modulation function, a separate light beam modulation means such as the electro-optic light modulator 7 can be omitted. (7) Furthermore, in each of the above embodiments, an afocal system is constructed by the imaging lens 4f and the lens 8;
It goes without saying that other optical systems may be used. Wandering Signal Processing Each of the above-mentioned embodiment apparatuses records a duplicate image along an arc-shaped scanning line corresponding to the rotation radius of the exposure head 4, so the image signal processing is performed using the conventional general method. A different method must be applied to image signal processing based on an orthogonal coordinate system, such as in image scanning recording devices. below,
We will explain this image signal processing method. First, image processing in the ξ computer 13 shown in FIG. 2 will be explained with reference to the flowchart shown in FIG. In addition, in the following explanation, FIG. 4(a)
As shown in Figure 2, the case of reciprocating exposure in the X-axis direction is taken as an example. Step S1: For example, when trying to record a pattern as shown by diagonal lines in FIG. 14, the minicomputer 1
Step 3 creates contour side vectors as shown by continuous arrows in the figure based on the CAD data of the pattern. The direction of each contour side vector is predefined so that the pattern area (n-light area) is on the right side. Step S2: This contour side vector is divided into a plurality of small regions P1 to P6 with a width corresponding to the intermittent feed pitch wv in the Y-axis direction, as shown in FIG. Here, the contour edge vector group is divided into 6 parts to simplify the explanation, but in reality it may be divided into even smaller parts. Step S3: Each of the small areas P1 to P6 shown in FIG. 15 is recorded in the direction shown by the broken line in the same figure, so the scanning start points 01-06 of each small area are set as the origin, and each Perform coordinate transformation of the contour edge vector for each small region. No.l
FIG. 6 shows a state in which the small areas P1 to P6 are rearranged in the order in which they are scanned and exposed.

Step S4: For convenience, data processing is performed from the smaller side of the X-axis to the larger side, so the direction is changed so that the starting point of the contour side vector of each region is on the smaller side of the X-axis. At this time, the definition that the exposure area is on the right side of each contour side vector is broken, so information (exposure information) indicating whether the exposure area is on the left or right side is added to each contour side vector whose direction has been changed. Step S5j Focusing on the starting point address of each contour side vector whose direction has been converted, each contour side vector data is sorted in ascending order in the X direction. Step S6: Output the sorted outline side vector data of each small area to the raster image processor 14 in the following units.
As shown in FIG. 17, each divided small area is divided into blocks made up of K lines parallel to the Y axis, each including an arc area scanned by a series of intersection points of the light beam. ．． Then, the contour side vector data of each block is sequentially outputted to the raster image processor 14, with a group of contour side vectors having a starting point address in each block as one unit. Image processing in the raster image processor 14 will be described below with reference to FIG. Figure 18 shows
FIG. 2 is a block diagram showing the configuration of the raster image processor 14 for each ma.

The minicomputer 13 transfers contour side vector data having a starting point within a block of K lines to the intersection calculation unit 14a of the raster image processor 14. The intersection calculation unit 14a calculates the intersection points between each of the K lines in the block and the contour side vector, that is, white/black (non-exposure/i-light) in scanning exposure, based on these contour side vectors.
Discipline the data at the change point. At this time, vectors that exceed the blocks for K lines are stored in the intersection calculation unit 14a as unprocessed carryovers until calculation processing of intersection data for the next block for K lines is performed. The intersection data for each block calculated by the intersection calculation unit 14a is transferred to the next-stage intersection data buffer memory 14b, and is stored in an address area divided for each line in the block. When the calculation of the intersection data for K lines is completed, the intersection data for one line is transferred from the intersection data buffer memory 14b to the Y-axis sorting unit l4C. The Y-axis sorting unit 14c sorts one line's worth of intersection data in ascending order by Y-axis address, and transfers it to the dot conversion unit 14d. The dot conversion unit 14d creates white/black dot data on the line based on the sorted intersection data for one line, and transfers it to the K line dot memory 14e.

The K line dot memory 14e sequentially stores K lines of white/black dot data sent line by line from the dot converter 14d.

The dont data for K lines is stored in the K line dot memory 14.
When stored in e, the arc line dot data conversion unit 14
f is determined by the order number of the light beam array for exposure arranged in the X direction and the rotation angle of the arm portion 4b of the exposure head 4.
The coordinate data of each exposure point on the arc line is calculated for each light beam, and the dot data corresponding to each coordinate data is sequentially read from the K line dot memory 14e, and the dot data along the arc line is adjusted. . When the dot data of one arc line is edited, the data is transferred to the arc line multi-dot memory 14g. When the dot data for one arc line is read out from the K line dot memory 14e, the dot data for one new line is transferred from the dot converter 14d to the K line dot memory 14e. Dot data for K lines is always stored and sequentially converted into dot data along arc lines.

When the arc line dot data of the number of scanning lines corresponding to the number of exposure light beams is stored in the arc line multi-dot memory 14g, the data of the light beam given from the scanning control circuit l2 is stored via the recording unit interface 14h. In synchronization with the position data of the irradiation point, dot data of the arc line corresponding to the scanning line of each light beam is read out from the arc line multi-dot memory 14g, and these dot data are transferred to the corresponding one of the electro-optic light modulator 7. Output to each channel. As a result, a plurality of light beams for exposure are modulated by dot data corresponding to each irradiation point, and a desired image pattern is recorded by exposure. <Effects of the Invention> As is clear from the above description, the present invention provides the following effects. (1) Since scanning exposure is performed while rotating the exposure head in a plane parallel to a flat photosensitive material such as a glass dry plate, the imaging lens is placed close to the photosensitive material regardless of the size of the photosensitive material. The light beam can be sufficiently focused. Therefore, according to the present invention, a pattern with high definition can be recorded on a planar photosensitive material. (2) Since scanning exposure is performed for each small divided area on the surface of the photosensitive material, the rotation radius of the exposure head can be set small. Therefore, according to the present invention, high-speed recording is possible by rotating the exposure head at high speed, and recording accuracy can be improved by downsizing the apparatus and improving the mechanical precision of the exposure head.

[Brief explanation of drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention.
The figure is a partially cutaway perspective view showing the general configuration of the device, Figure 2 is a block diagram showing the schematic configuration of the control system of the device, Figure 3 is an explanatory diagram of arcuate main scanning, and Figure 4 is a sub-section diagram. It is an explanatory diagram of scanning feed. 5 to 8 relate to the second embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the deviation of the scanning line trajectory due to continuous sub-scanning feed,
FIG. 6 is a block diagram showing the general structure of the control system, FIG. 7 is a perspective view showing the structure of the beam shifter, and FIG. 8 is a functional explanatory diagram of the beam shifter. FIG. 9 is a block diagram showing a schematic configuration of a control system according to a third embodiment of the present invention. FIG. 10 and FIG. 11 relate to the fourth embodiment of the present invention,
Figure 1 is a block diagram showing the general structure of the control system.
FIG. 1 is an explanatory diagram of the focus detection operation. FIG. 12 is an explanatory diagram of main parts of a modification of the present invention. 13 to 18 are explanatory diagrams of an example of image processing of the embodiment apparatus, FIG. 13 is a flowchart showing the processing procedure of the ξ2 computer, and FIGS. 14 and 15. 1st
6 and 17 are explanatory diagrams of a method of processing contour side vector data, and FIG. 18 is a block diagram showing the general structure of a raster image processor. 1...Table 2...1th sub-scanning feed mechanism 3...2nd sub-scanning feed mechanism 4...Exposure head 4C...Rhompoid prism 4d...1st reflective surface 4e ...Second reflective surface 4f...Imaging lens 4g...Direct drive motor 5...Light source 7...Electro-optic light modulator 10a...Rotary encoders 10b, 10c...Linear encoder 12... Scanning control circuit 13... Computer 14... Frame memory

Claims (1)

[Claims] (1) An image scanning recording device that sequentially scans and exposes a planar photosensitive material in each divided area using arcuate scanning lines, comprising: a table on which the photosensitive material is mounted; sub-scan feeding means for sub-scan feeding in two orthogonal in-plane axes directions, an exposure head rotatably driven in a plane parallel to the table surface, a sub-scan feeding position of the table and a rotation angle of the exposure head; a position detection means for detecting the scanning position of the light beam from the position detection means; an image output control means for outputting image data corresponding to the position based on the position data from the position detection means; a light source for generating the light beam; a light beam modulator that modulates the light beam emitted from the light source based on image data from the image output control means; and an imaging lens that focuses the light beam modulated by the light beam modulator on a photosensitive material surface. The sub-scanning feeding means includes a first sub-scanning feeding mechanism that feeds the table intermittently or continuously in a first sub-scanning direction in relation to arc-shaped main scanning by the exposure head; a second sub-scanning feed mechanism that intermittently moves the table in a second sub-scanning direction perpendicular to the sub-scanning feed of the exposure head in a width smaller than the rotation radius of the exposure head, and the exposure head a first reflecting section that receives a light beam modulated by the means along the center of the rotation axis and reflects the incident light beam in the direction of the rotation radius; and a second reflecting section that reflects the reflected light beam toward the table surface.
An image scanning and recording apparatus comprising: a reflecting section; and a rotational drive section that integrally rotates the first reflecting section and the second reflecting section.