JP2000227661A - Scanning type plotting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning type plotting device capable of always realizing plotting at a fixed position on a roll sheet type medium even the medium is positionally deviated. SOLUTION: In this scanning type plotting device 1, a laser beam emitted from a light source is modulated by an optical modulator, deflected by a deflector and formed into an image on the plotting surface of a plotting table 12 by a scanning lens, then the medium M placed on the plotting surface is scanned by the laser beam so as to perform plotting. In such a case, the device 1 is provided with an image sensor 60 acquiring the image data of the medium M and an image processing part obtaining a displacement value Δd showing how much the medium M is deviated from a specified standard position based on the image data. By correcting a plotting start position Ds according to the displacement value Δd, the same result of the plotting as that obtained when the medium M is at the standard position is obtained even when the medium M is deviated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning type drawing apparatus for drawing a desired image on a medium by scanning the medium with a laser beam, for example, a printed circuit board exposure apparatus, a laser photoplotter, and a laser. The present invention relates to a scanning type drawing device such as a printer.

[0002]

2. Description of the Related Art Conventionally, a scanning type drawing apparatus such as a printed board exposure apparatus performs drawing by scanning a cut sheet-shaped medium, that is, a substrate material for a printed wiring board, with a laser beam. Was. This substrate material is obtained by forming a conductive thin film on an insulating layer and coating the conductive thin film with a photoresist. The scanning drawing apparatus scans such a substrate material with a laser beam, thereby exposing a desired substrate pattern to the photoresist layer. Then, the substrate can be manufactured by subjecting the processed substrate material to photoetching.

FIG. 11 is a schematic perspective view showing the configuration of a conventional scanning type drawing apparatus. This scanning type drawing apparatus includes a light source 90 and an exposure optical system 91 which are fixedly provided.
And a drawing table 92 slidably disposed in the X direction in the drawing.

A laser beam emitted from a light source 90 is applied to a drawing surface 93 on a drawing table 92 via a scanning optical system arranged in an exposure optical system 91 to form a scanning line in a Y direction orthogonal to the X direction. Form S. Note that the operator or the robot places and fixes a substrate material to be drawn on the drawing surface 93 of the drawing table 92 in advance.

The laser light emitted from the light source 90 is guided to an exposure optical system 91 and modulated, and then reaches a drawing surface 93. By scanning a substrate material placed on the drawing surface 93, the laser light is scanned. The photoresist layer of the substrate material is exposed.
The scanning by the laser beam is performed in the Y direction along the scanning line S. While the one scan is being performed, the drawing table 92 is moved by one scan width in the X direction (sub-scan direction) in FIG. 11, so that the next scan can be continuously performed.

[0007] After repeating this scanning and drawing on the entire drawing surface 93, the operator or robot releases the substrate material from the drawing table 92 and picks it up. A printed wiring board is manufactured by subjecting the substrate material after the exposure processing to a photoetching processing.

[0007]

However, in the above-described conventional scanning type drawing apparatus, since a cut sheet-shaped medium is used, the medium is stored in a drawing table of the scanning type drawing apparatus using a robot or the like. After placing and scanning, the processed medium must be removed from its drawing table.

[0008] Here, if a medium in the form of a roll sheet is used as the medium, the above-described loading and unloading steps are not required, and the processing efficiency is improved. With the rolled sheet-like medium extended on the drawing table on the drawing surface of the drawing table,
When the medium is fed and wound, the medium may be misaligned. That is, there is a problem that the medium is easily offset from a predetermined standard position on the drawing surface of the medium.

Accordingly, it is an object of the present invention to provide a scanning type drawing apparatus which can always draw at a fixed position on a medium even when the medium is misaligned.

[0010]

In order to solve the above-mentioned problems, the scanning type drawing apparatus according to the present invention employs the following configuration.

That is, a drawing apparatus according to a first aspect of the present invention provides a drawing table having a drawing surface on which a flexible sheet-shaped medium that can be wound into a roll is placed, a laser light source, An optical modulator for modulating laser light emitted from the laser light source, and scanning the laser light emitted from the optical modulator along a predetermined scanning line from a predetermined scanning start end to a predetermined scanning end on the drawing surface. The scanning optical system to be performed, and the position at which the laser light has moved by a predetermined standby interval value along the scanning line from the scanning start end as a drawing start end, so that drawing on the medium is started from the drawing start end. Control means for controlling an optical modulator, comprising: a displacement indicating how much the medium is displaced from a predetermined standard position on the drawing surface in a direction along a scanning line. Quantification to get the value Means, wherein the control means corrects the standby interval value according to the displacement value, so that the same drawing result as when the medium is always at the standard position is obtained regardless of the actual position of the medium. Thus, the method is characterized in that the optical modulator is controlled.

[0012] With this configuration, the displacement value obtaining means can determine how much the medium placed on the drawing surface of the drawing table is displaced in a direction along the scanning line from a predetermined standard position. Detected as a displacement value, and sends the displacement value to the control means. Then, the control unit performs scanning after correcting the standby interval position based on the displacement value. That is, the control means controls the optical modulator, and sets a position shifted from the scanning start end of the scanning line along the scanning line by the corrected standby interval value as a corrected drawing start end, and Start drawing on the medium from the drawing start end. When drawing is performed in this manner, even when the medium is placed with a deviation from the standard position on the drawing surface, the drawing start position also moves in accordance with the deviation, so that the drawing result is always constant on the medium. Position.

According to a second aspect of the present invention, there is provided a scanning type drawing apparatus, wherein the displacement value obtaining means according to the first aspect processes an image sensor for obtaining image data of a medium placed on a drawing surface, and processes the image data. And an image processing unit for determining the displacement value.

The image sensor has a CCD, and the image processing unit performs pattern matching,
Alternatively, image processing by binarization may be performed. In addition, image acquisition and image processing may be performed simultaneously using a vision chip using an analog integrated circuit.

According to a third aspect of the present invention, in the scanning type drawing apparatus according to the second aspect, the image sensor is arranged so as to be able to acquire image data around the end face of the medium, and the image processing unit is configured to:
The displacement value is determined by detecting the position of the end face of the medium from the image data, and determining the displacement value.

According to a fourth aspect of the present invention, in the scanning type drawing apparatus according to the second aspect, the medium has a mark at a predetermined position, and the image sensor includes the mark and the vicinity of the mark. The image processing unit is arranged so as to be capable of acquiring the image data, and the image processing unit specifies the displacement value by detecting a mark position of the medium from the image data.

According to a fifth aspect of the present invention, in the scanning type drawing apparatus according to any one of the first to fourth aspects, the scanning type drawing apparatus is arranged at a position optically equivalent to the scanning line, and is scanned by a laser beam. A monitor scale for generating a pulse having a cycle corresponding to a scanning speed and transmitting the pulse to the control unit; a drawing light for forming the scanning line by using the laser light emitted from the laser light source; The monitor light that scans on the scale, light branching means for branching further, the control means, in correspondence with the pulse of the monitor scale, after converting the standby interval value to the number of standby interval pulses, From the scanning start end of the scanning line, start counting the pulses of the monitor scale,
The light modulator is specified by controlling the optical modulator so as to start drawing after counting the number of pulses at the standby interval.

According to a sixth aspect of the present invention, there is provided the scanning type drawing apparatus according to any one of the first to fifth aspects, further comprising: a loader for storing the medium and feeding the medium; and an unloader for winding the medium. The loader and the unloader are specified by arranging the loader and the unloader such that the medium extending between the loader and the unloader is placed on the drawing surface of the drawing table.

According to a seventh aspect of the present invention, in the scanning type drawing apparatus according to any one of the first to sixth aspects, each time the medium is placed on the drawing surface of the drawing table,
Prior to drawing, the displacement value is specified by controlling the displacement value acquiring means to acquire the displacement value and correct the standby interval value.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

<Structure of Scanning Drawing Apparatus> In a scanning drawing apparatus according to an embodiment of the present invention, a substrate M for a printed wiring board formed in a roll sheet shape is used as a drawing target medium.
(Hereinafter, abbreviated as medium M). The medium M is formed by forming a metal thin film layer such as a copper foil on a flexible film-like insulating layer, and further coating the metal thin film layer with a photoresist such as polyimide to form a sheet. ,
The sheet is wound into a roll. The scanning type drawing apparatus 1 includes an exposure apparatus 2 for exposing the medium M by scanning with a laser beam, a loader 4 for sending the medium M to the exposure apparatus 2, and an unloader 5 for winding the medium M after the exposure processing. And.

FIG. 1 is a side view showing a schematic configuration of the scanning type drawing apparatus 1. As shown in FIG. The exposure apparatus 2 includes a scanning optical system 3 that performs laser beam scanning, a drawing table 12 that slides under the scanning optical system 3 with the medium M placed, and an image sensor 60 for detecting the position of the medium M. Having. In addition,
The image sensor 60 is arranged so that the periphery of the end face of the medium M on the depth side in FIG.
Further, the drawing table 12 includes a fixing claw 12A that can fix the medium M.

The loader 4 includes a supply roller 70 for winding the unused medium M, a drive roller pair 71 for sending the medium M from the supply roller 70, and a medium M sent from the drive roller pair 71. It has a guide roller 72 for guiding, a pair of clamp rollers 73 capable of clamping the medium M guided by the guide roller 72, and a sensor 74 for detecting the state of the medium M. This clamp roller pair 73
Can take either a fixed state in which the medium M is clamped and fixed, or an open state in which the medium M is released.

The unloader 5 includes a drive roller pair 80 for taking the medium M exposed by the exposure device 2 into the unloader 5, a guide roller 81 for guiding the medium M sent by the drive roller pair 80, It has a take-up roller 82 for winding and storing the medium M guided by the guide roller 81, and sensors 83 and 84 for detecting the state of the medium M. The drive roller pair 80 can assume either a transport state in which the medium M is transported by rotating the roller, or a fixed state in which the medium M is fixed.

FIG. 2 is a block diagram of the scanning type drawing apparatus 1. The main control unit 6 includes a drawing control unit 7 and a machine control unit 8
, And control is performed. Also, the machine control unit 8
Are connected to the drawing control unit 7 and the loader / unloader control unit 9, respectively. The main control unit 6, the drawing control unit 7, the machine control unit 8, and the loader / unloader control unit 9 function as control means of the scanning drawing device 1.

An acousto-optic modulator (AO) as an optical modulator
M) 30 is the laser light source 10 under the control of the drawing control unit 7.
Modulation of the laser light emitted from the controller, that is, ON / OFF switching. The laser light modulated by the AOM 30 scans the drawing table 12 as drawing light. As will be described later, when the monitor light synchronized with the drawing light scans on the monitor scale 47, the drawing control unit 7 sets the current drawing light to the drawing table 12
It is possible to detect which position on the screen is being scanned.

The image sensor 60 has a CCD, is arranged so that the periphery of the end face of the medium M is in the field of view, and sends out the obtained image data to the image processing section 61. The image processing unit 61 performs image processing by pattern matching described later on the image data obtained by the image sensor 60, and sends the processing result to the drawing control unit 7. Note that the image sensor 60 and the image processing unit 61 function as displacement value acquiring means.

The machine control unit 8 includes an image processing unit 61 and X
Each is connected to the axis control unit 62. This X-axis controller 62
Controls the X-axis motor 63 via a servo (not shown) to cause the drawing table 12 to slide.
The loader / unloader control unit 9 includes a loader drive motor 7
5, control is performed by being connected to the clamp roller pair controller 76, the unloader drive motor 85, and the drive roller pair controller 86, respectively.

The loader drive motor 75 is connected to the supply roller 7
By driving the drive roller 71 on the side of the loader 4 and the medium M, the medium M is sent out. The sensor 74 includes a pair of a light emitting element and a light receiving element (not shown), detects whether the medium M is located at a predetermined medium lower limit position, and sends the detection result to the loader / unloader control unit 9. The clamp roller pair control unit 76 controls the clamp roller pair 73 to set the medium M in a fixed state in which the medium M is clamped and fixed, or in an open state in which the medium M is released.

The drive roller pair control unit 86 controls the drive roller pair 80, and sets the drive roller pair 80 to a transport state for transporting the medium M or a fixed state for fixing the medium M. The unloader driving motor 85 drives the take-up roller 82 to drive the medium M fed into the unloader 5.
Take up. The upper limit sensor 83 includes a pair of a light emitting element and a light receiving element (not shown), and the medium M is located at a predetermined medium upper limit position.
Is detected, and the detection result is sent to the loader / unloader control unit 9. Lower limit sensor 84
Comprises a pair of a light emitting element and a light receiving element (not shown), detects whether or not the medium M is located at a predetermined medium lower limit position, and sends the detection result to the loader / unloader control unit 9.

(Scanning Optical System of Exposure Apparatus) FIG. 3 is a perspective view showing the structure of the exposure apparatus 2. Hereinafter, the scanning optical system 3 of the exposure apparatus 2 will be described in detail with reference to FIG.

The exposure apparatus 2 includes a laser light source 10 and an optical table 11 which are fixedly provided, and a drawing table 12 which is slidably provided in the X direction in the drawing. Here, an argon laser is used as the light source 10, and the laser light emitted from the light source 10 is
A scanning line S in the Y direction orthogonal to the X direction is formed on the drawing surface 13 on the drawing table 12 via the scanning optical system arranged in 1. The scanning line S is a line segment that starts at the scanning start end Ss and ends at the scanning end end Sf.

The laser light emitted from the light source 10 disposed below the optical bench 11 is reflected by the mirrors 20 and 21 and passes through an optical path hole 11a formed in the optical bench 11.
After being reflected by the mirror 22, the beam diameter is adjusted by the variable power lens system 23. This adjustment is performed to correct a change in the beam diameter due to the characteristics of the light source 10. The laser light transmitted through the variable power lens system 23 is reflected by a half mirror 24 as a light splitting unit, and is drawn by drawing light L ₁ (shown by a solid line in FIG. 3) and transmitted monitor light L ₂ (one point in FIG. 3). (Indicated by a chain line).

The drawing light L ₁ is split into two by the half mirror 25, and the reflected drawing light enters the beam separator 26 a, and the transmitted drawing light enters the beam separator 26 b via the mirror 27. Each beam separator 26
a and 26b have a function of further separating each drawing light into a plurality of lines. In the example shown here, each drawing light is 8
Although they are separated into books, they are shown by three lines in FIG. 3 for convenience of illustration.

Each of the separated drawing lights is applied to a mirror 28.
The beam intervals are narrowed by first reduction optical systems 29a and 29b composed of a pair of lens groups disposed with the lenses a and 28b interposed therebetween, and are incident on multi-channel AOMs 30a and 30b. Each of the AOMs 30a and 30b includes a plurality of modulation units that can be independently modulated, and independently modulates each drawing light. Each drawing light modulated by one AOM 30a directly enters the beam splitter 32, and each drawing light modulated by the other AOM 30b is reflected by the mirror 31,
The light enters the beam splitter 32. That is, both AOMs
The drawing light originating from the beam splitters 30a and 30b is
And then proceed on the same optical path.

After the combined drawing light is reflected by the mirror 33, the beam interval is reduced by the second reduction optical system 35 composed of a pair of lens groups disposed with the mirror 34 interposed therebetween. The light enters the rotator 36. The image rotator 36 adjusts the direction so that a plurality of parallel drawing lights are properly arranged on the drawing surface 13.

The monitor light L ₂ transmitted through the half mirror 24 is reflected by the mirror 50, passes through the monitor light reduction optical system 51, the monitor light magnification adjusting optical system 52, and is reflected by the mirror 53. Between the rear group lens of the second reduction optical system 35 and the image rotator 36, the light is reflected by a mirror 54 disposed outside the optical path of the drawing light and merges with the drawing light.

The drawing light and monitor light emitted from the image rotator 36 are reflected by mirrors 37 and 38, pass through a collimating lens 39, are reflected by a mirror 40, and enter a polygon mirror 41 as a deflector. The polygon mirror 41 has approximately eight reflecting surfaces on eight sides.
It is shaped like a prism and rotates clockwise in FIG. 3 around the central axis of the prism, and simultaneously reflects and deflects the drawing light and the monitor light. Each reflection surface of the polygon mirror 41 corresponds to one scan. That is, the polygon mirror 41
The scanning is performed eight times during one rotation.

The drawing light and monitor light reflected and deflected by the polygon mirror 41 are transmitted to an fθ lens 4 serving as a scanning lens.
2, the mirror 43 and the condenser lens 44
Through to the drawing surface 13. The mirror 45 is disposed outside the optical path of the drawing light, and reflects only the monitor light toward the mirror 46.

The drawing light travels straight to reach the drawing surface 13 and scans the drawing surface 13. There are a plurality of drawing lights, which scan the drawing surface 13 in parallel with S in a state where they are arranged in a direction orthogonal to the scanning lines S. Therefore, while simultaneously drawing a plurality of dots (here, 16 dots) arranged in the sub-scanning direction (X direction in FIG. 3), scanning can be performed in the Y direction in FIG. Drawing becomes possible.

The drawing light turned on by the AOMs 30a and 30b reaches the drawing surface 13, and sensitizes a corresponding portion of the medium M placed on the drawing surface 13 to form dots. Since the drawing light turned off at 30b does not reach the drawing surface 13, the drawing surface 13
The corresponding part of the upper medium M is left unexposed. Therefore, the drawing control unit 7 shown in FIG. 2 sets the AOMs 30a and 30b to O based on the drawing data acquired from the main control unit 6.
By performing N / OFF, an image indicated by the drawing data can be drawn on the medium M.

The monitor light separated from the drawing light by the mirror 45 is reflected by the mirror 46 and scans on the monitor scale 47. The monitor scale 47 is a transparent plate on the surface of which a large number of opaque lines are formed at equal pitches, and a monitor signal scans over the transparent plate, so that a pulse signal is generated from a light receiving element (not shown) that detects transmitted light. Is output. Since this pulse-like signal is generated according to the opaque portion and the transparent portion on the monitor scale 47, the number of pulses corresponds to the scanning distance, and the pulse period corresponds to the scanning speed. Therefore, the drawing controller 7 causes the drawing light to be generated by the pulse sent from the light receiving element.
It is possible to detect which position on the screen is being scanned.

During one scan, the drawing table 12 moves by 16 dots in the X direction (sub-scanning direction) in FIG. 3 while the medium M is mounted and fixed on the drawing surface 13. Therefore, at the end of the scan, the next scan can be continued. At this time, the polygon mirror 41
The drawing light and the monitor light impinge on the boundary between the adjacent reflecting surfaces of. And the next scanning is started by further rotating the polygon mirror 41. The drawing light is again shifted from the scanning start end Ss to the scanning end Sf of the scanning line S.
The range up to is scanned in the Y direction in FIG.

Here, the scanning start end Ss and the scanning end end S
f, the drawing start end Ds and the drawing end end Df will be described. When the drawing light and the monitor light impinge on the boundary between adjacent reflecting surfaces of the polygon mirror 41,
The drawing light is located on the drawing surface 13 at the scanning start end Ss. At this time, the monitor light irradiates the corresponding portion on the monitor scale 47. Further, the drawing control unit 7 uses a sensor (not shown) to generate a drawing light at that time on the drawing surface 13.
It is possible to detect that it is located at the upper scanning start end Ss.

Since the polygon mirror 41 is always rotating clockwise in FIG. 3, the position of the drawing light on the drawing surface 13 advances in the Y direction along the scanning line S from the scanning start end Ss. The monitor light travels on the monitor scale 47 in synchronization with the drawing light, and the monitor scale 47 generates a pulse corresponding to the opaque portion and the transparent portion.
Therefore, the drawing control unit 7 can monitor the progress of drawing light on the drawing surface 13, that is, the current position, by counting the pulses of the monitor scale 47.

When the drawing light is located at the scanning start end Ss on the drawing surface 13, the drawing control unit 7 sets the AOM 30 (a,
Since b) is in the OFF state, the drawing light is not actually emitted from the AOM 30. Therefore, although the drawing light does not irradiate the drawing start end Ss, the monitor light constantly scans the monitor scale 47, so that the drawing control unit 7
If AOM30 was ON at that time,
It can be detected that the drawing light should be located at the drawing start end Ss. Thus, AOM30 is O
The virtual drawing light that would have existed if it was in the N state is hereinafter referred to as virtual drawing light for convenience.

After the monitor scale 47 detects that the virtual drawing light is located at the scanning start end Ss by the monitor scale 47, it counts output pulses from the monitor scale 47. Then, after counting the number of pulses corresponding to the “standby interval value” described later, drawing is started. At this point, the drawing light is applied to the drawing start end D on the scanning line S.
s. The drawing control unit 7 controls the drawing start end D
A range from s to the drawing end Df is defined as a drawing range, and ON / OFF control of the AOM 30 is performed based on the drawing data.
When the drawing light reaches the drawing end Df on the scanning line S, the drawing control unit 7 turns off the AOM 30 and ends the drawing. However, since the polygon mirror 41 is continuously rotating, the virtual drawing light travels on the scanning line S at the drawing end end D.
From f to the scanning end end Sf. Immediately after the virtual drawing light is located at the scanning end end Sf, the monitor light and the virtual drawing light hit the boundary between the adjacent reflecting surfaces of the polygon mirror 41, and the virtual drawing light is The scanning is started again from the scanning start end Ss.

(Exposure Position Correction) Since the medium M is in the form of a roll sheet, the medium M is extended between the loader 4 and the unloader 5 and the drawing surface 13 of the drawing table 12 is
When placed on top, the medium M may be shifted from a predetermined standard position. In particular, an end face position shift in which the end face position of the medium M is offset easily occurs.

The scanning type drawing apparatus 1 of the present embodiment
Each time is placed on the drawing surface of the drawing table 12, a position shift of the end face of the medium M is detected before drawing, and the medium M
By correcting the exposure position with respect to, it is possible to always expose a predetermined position of the medium M. Hereinafter, this exposure position correction will be described with reference to FIGS. 4, 5, and 6. FIG.

FIG. 4 is a schematic plan view schematically showing the medium M, the scanning lines S, and the image sensor 60 placed on the drawing surface 13 of the drawing table 12. The scanning is performed along the scanning line S from the scanning start end Ss to the scanning end end Sf. However, actually, the drawing control unit 7 shown in FIG.
However, the AOM 30 is controlled to draw the drawing data for one scan only in the drawing range D from the drawing start end Ds to the drawing end end Df. The drawing control unit 7 always keeps the AOM 30 in the OFF state outside the drawing range D.

When the medium M is correctly set at a predetermined standard position, the drawing range D corresponds to a predetermined position on the medium M. However, the medium M indicated by a two-dot chain line in FIG.
When the end face position deviation from the standard position occurs as in ′, the drawing range D does not correspond to a predetermined position on the medium M ′. At a predetermined position.

Therefore, the image sensor 60 (and FIG.
The image processing unit 61 shown in FIG. 1 obtains the end face position deviation amount Δd from the standard position (hereinafter, referred to as “displacement value”), and performs exposure position correction.

First, the process of acquiring the displacement value Δd by the image sensor 60 and the image processing unit will be described. Image sensor 6
Reference numeral 0 denotes a CCD, which acquires image data around the end face of the medium M and sends it to the image processing unit 61. Since the image sensor 60 covers the periphery of the end face of the medium M in a wide field of view, even when the end face position shifts as in the case of the medium M ′, the end face portion of the medium M ′ is within the field of view. I'm catching.

The image processing section 61 specifies the position of the end face of the medium by performing a pattern matching process on the image data acquired by the image sensor 60. That is, the image sensor 60 acquires the image data of the medium M placed at the standard position in advance, registers the image data in a memory (not shown) as master data, and The actual end face position is specified by comparing the image data obtained during operation with the master data. By comparing the actual end face position thus obtained with the standard position, the displacement value Δd can be obtained.

Next, the exposure position is corrected based on the obtained displacement value Δd. In FIG. 4, the medium M ′ is offset by Δd in the direction of the scanning end Sf. Therefore, the drawing start end Ds is also corrected so as to be offset by Δd in the direction of the scanning end end Sf, and drawing is started from the corrected drawing start end Ds ′. The position at which drawing data for one scan is drawn along the scanning line S from the drawing start end Ds 'is the corrected drawing end Df'. That is, the drawing control unit 7 controls the AOM 30 to execute the drawing in the drawing range D ′ from the corrected drawing start end Ds ′ to the drawing end end Df ′.

As described above, by performing the exposure position correction, it is possible to expose the medium M 'in which the positional deviation has occurred, to the same correct position as the medium M at the standard position. FIG. 5A schematically shows the drawing result R on the medium M at the standard position, and FIG. 5B shows the corrected drawing result R 'on the medium M' having a positional shift. Is shown. Comparing FIGS. 5A and 5B, it can be seen that the drawing result R ′ is offset from the drawing result R by the displacement value Δd of the medium M ′ with respect to the medium M. Therefore, the position of the drawing result R on the medium M matches the position of the drawing result R 'on the medium M'.

Further, the exposure position correction control by the drawing control unit 7 will be described with reference to FIG. FIG. 6A shows the medium M
At the standard position, and FIG. 6B shows the medium M ′
4 and 5 show a case where the end face is offset toward the scanning end end Sf, and FIG. 6C shows a case where the end face is offset toward the scanning start end Ss.

The image processing device 61 obtains the displacement value Δd as described above based on the image data sent from the image sensor 60 and sends it to the machine control unit 8. Further, the machine control unit 8 calculates how many pulses the displacement value Δd corresponds to with reference to the pulse determined by the scale of the monitor scale 47. That is, the displacement value Δd is set to the displacement pulse number ΔP
(ΔP is an integer). If the medium end face is offset toward the scanning end Sf, the sign of the number of displacement pulses is set to plus, and if the medium end face is offset toward the scanning start end Ss, the sign of the displacement pulse is set. To minus. The displacement pulse number ΔP thus obtained is sent to the drawing control unit 7.

The drawing controller 7 starts counting of the monitor scale 47 from the scanning start end Ss, and after counting the number of standby interval pulses P as a standby interval value, sets the AO.
M30 is controlled to start drawing. The standby interval pulse number P is obtained by adding the displacement pulse number ΔP to a predetermined standard standby interval pulse number P ₀ . That is, the number of waiting interval pulses P can be calculated by the following equation: P = P ₀ + ΔP

As shown in FIG. 6A, when the medium M is at the standard position, that is, when the number of displacement pulses ΔP is 0, P = P ₀ . When the virtual drawing light reaches the scanning start end Ss, the drawing control unit 7 detects this by a sensor (not shown), starts counting the monitor scale 47 from that point, and sets the standard standby interval pulse number P _0. , The AOM 30 is controlled to start drawing.

As shown in FIG. 6B, the number of displacement pulses Δ
If P is a positive number, P = P ₀ + ΔP = P ₀ + | ΔP |
The drawing control unit 7 starts counting the monitor scale 47 from the scanning start end Ss, counts the number of standard standby interval pulses P ₀ , further counts ΔP, and then controls the AOM 30 to perform drawing. Start.

As shown in FIG. 6C, the number of displacement pulses Δ
If P is a negative number, P = P ₀ + ΔP = P ₀ − | ΔP |
The drawing control unit 7 starts counting of the monitor scale 47 from the scanning start end Ss, and after counting P ₀ − | ΔP |, controls the AOM 30 to start drawing.

<Operation of Embodiment> FIGS. 7 and 8 are explanatory views of the medium transport operation. Each step of the flowchart of FIG. 9 will be described below with reference to these figures.

(S1) First, the loader / unloader controller 9 shown in FIG. 2 controls the clamp roller pair controller 76 to fix the clamp roller pair 73 of the loader 4 and to control the drive roller pair. The medium M is fixed by controlling the unit 86 to set the driving roller pair 80 of the unloader 5 in a fixed state. In this state, the machine control unit 8
Controls the air flow control unit (not shown) to release the fixed claws 12A of the drawing table 12 as shown in FIG. 7, and then controls the X-axis control unit 62 to drive the X-axis motor 63. Causes the drawing table 12 to slide to the left in FIG.

When the drawing table 12 is set at the position shown in FIG. 8, the machine control section 8 fixes the medium M on the drawing table 12 by the fixing claws 12A of the drawing table 12. Then, the loader / unloader control unit 9 controls the clamp roller pair control unit 76 to open the clamp roller pair 73 of the loader 4 and to set the loader drive motor 75
To rotate the supply roller 70 of the loader 4 in the counterclockwise direction in FIG. 8 and drive the drive roller pair 71 of the loader 4 to send out the medium M until the sensor 74 detects the medium M. The medium M sags in the loader 4. That is, when the medium M sags to the sensor 74, the supply roller 70 and the drive roller pair 71 stop.

(S2) In this state, the image sensor 60
The image data around the end face position of the medium M fixed to the drawing surface 13 of the drawing table 12 is acquired and sent to the image processing unit 61.

(S3) The image processing section 61 performs the following based on the acquired image data and the master data registered in advance.
By performing pattern matching, a displacement value Δd indicating a deviation of the actual medium end surface position from the standard position is obtained.

(S4) Further, the machine control section 8 converts the displacement value Δd into a displacement pulse number ΔP corresponding to the pulse of the monitor scale 47, and then converts this displacement pulse number ΔP.
The sum of P and the previously stored standard standby interval pulse number P ₀ is sent to the drawing control unit 7 as the standby interval pulse number P. The drawing control unit 7 stores the standby interval pulse number P as the standby interval value in a memory (not shown), and thereafter applies the same to all scans of one drawing surface 13.

(S5) Next, the machine control section 8 controls the X-axis control section 62 to start driving the X-axis motor so as to slide the drawing table 12 rightward in FIG. When the drawing controller 7 detects that the position of the virtual drawing light has reached the scanning start end Ss by a sensor (not shown), the drawing controller 7 starts pulse counting of the monitor scale 47 and counts the number P of the standby interval pulses. From where I did
The AOM 30 is controlled to start drawing.

If the above scanning is repeated while sliding the drawing table 12 to the right in FIG. 8, the medium M between the drawing table 12 and the unloader 5 becomes slack. , Drawing table 1
While the slide 2 is being performed, control is performed via the drive roller pair control unit 86 so that the drive roller pair 80 is always rotated to take in the medium M into the unloader 5. And
The loader / unloader control unit 9 drives the unloader drive motor 85 to rotate the winding roller 82 in the counterclockwise direction in FIG.

The loader / unloader control unit 9 always monitors the slack of the medium M in the unloader 5 by the upper limit sensor 83 and the lower limit sensor 84, and controls the slack to be kept within an appropriate range.

That is, when the upper limit sensor 83 does not detect the medium M, the loader / unloader controller 9 stops the unloader driving motor 85 to interrupt the winding, and
To sag. Since the drive roller 80 always takes in the medium M into the unloader 5, the slack of the medium M in the unloader 5 increases. Then, the lower end of the medium M reaches the position of the lower limit sensor 84, and the lower limit sensor 8
4 detects the medium M, the loader / unloader controller 9
Drives the unloader drive motor 85 again to restart the winding of the medium M by the winding roller 82. As described above, the control of the loader / unloader control unit 9 ensures that the slack of the medium M in the unloader 5 is always kept in an appropriate range.

(S6) When the scanning of one drawing surface 13 is completed, the state shown in FIG. 7 is returned again. Here, when the exposure is continued, the above-described processing is repeated from S1, whereby the roll sheet-shaped medium M can be continuously exposed. That is, every time a medium M on which an image has not been drawn is newly placed on the drawing surface 13, a shift in the medium position is detected in advance and the exposure position is corrected before drawing on the medium M is performed. Even when exposure is performed continuously, desired data is always exposed at a correct position on the medium M.

<Modification> By changing the configuration of the above-described embodiment, the marks m are placed on the medium in advance at a fixed position from the end face and at a constant interval along the longitudinal direction of the medium.
May be printed, and when the medium Mm is fixed on the drawing surface 13, the image sensor 60 ′ may be arranged such that the periphery of the position of the mark m falls within the field of view. FIG. 10 shows the positional relationship between the mark m and the image sensor 60 'when using the medium Mm provided with the mark m. The image sensor 60 ′ is arranged not to cover the periphery of the end face of the medium Mm in the field of view but to cover the mark m and the periphery thereof around the mark m.

The master data registered in the image processing section 61 includes the image data around the mark m obtained by the image sensor 60 ′ when the medium Mm is fixed at the standard position on the drawing surface 13. I do. Other configurations, ie,
Except for the medium Mm, the image sensor 60 ', and the master data of the image processing unit 61, the configuration is the same as that of the above-described embodiment.

[0076]

According to the scanning type drawing apparatus of the present invention configured as described above, even if the medium is displaced on the drawing table, the drawing start position is determined in accordance with the position shift. By performing the adjustment, it is possible to always obtain the same drawing result as when the medium is at the standard position.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of a scanning type drawing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a scanning drawing apparatus according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of an exposure apparatus.

FIG. 4 is an explanatory diagram of an exposure position correction process.

FIG. 5 is an explanatory diagram of an exposure position correction process.

FIG. 6 is an explanatory diagram of an exposure position correction process.

FIG. 7 is an explanatory diagram of a medium transport operation.

FIG. 8 is an explanatory diagram of a medium transport operation.

FIG. 9 is a flowchart showing the operation of an embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a modification of the embodiment.

FIG. 11 is a perspective view showing a schematic configuration of a conventional scanning type drawing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanning drawing apparatus 2 Exposure apparatus 3 Scanning optical system 4 Loader 5 Unloader 6 Main control part 7 Drawing control part 8 Machine control part 9 Loader / unloader control part 10 Laser light source 12 Drawing table 13 Drawing surface 24 Half mirror 30 AOM 41 Polygon Mirror 42 fθ lens 47 monitor scale 60 image sensor 61 image processing unit M, M ′, Mm medium S scan line Ss scan start end Sf scan end end Ds drawing start end Df drawing end R, R ′ drawing result m mark

Claims (7)

[Claims] 1. A drawing table having a drawing surface for mounting a sheet-shaped medium having flexibility and capable of being wound into a roll, a laser light source, and a laser light emitted from the laser light source. An optical modulator for modulating; a scanning optical system for scanning a laser beam emitted from the optical modulator along a predetermined scanning line from a predetermined scanning start end to a predetermined scanning end end on the drawing surface; Control means for controlling the optical modulator so that a position moved by a predetermined standby interval value along a scanning line from the scanning start end by a predetermined standby interval value as a drawing start end, so as to start drawing on the medium from the drawing start end. A displacement type acquisition unit for acquiring a displacement value indicating how much the medium is displaced in a direction along a scanning line from a predetermined standard position on the drawing surface. Further comprising: The means corrects the standby interval value according to the displacement value, and controls the optical modulator so that a drawing result similar to the case where the medium is at the standard position is always obtained regardless of the actual position of the medium. A scanning type drawing apparatus characterized by controlling. 2. The image processing apparatus according to claim 1, wherein the displacement value acquiring unit includes: an image sensor that acquires image data of a medium placed on a drawing surface; and an image processing unit that processes the image data to determine the displacement value. The scanning type drawing apparatus according to claim 1, wherein: 3. The image sensor is arranged so as to acquire image data around a medium end face, and the image processing section obtains the displacement value by detecting an end face position of the medium from the image data. 3. The scanning type drawing apparatus according to claim 2, wherein: 4. The medium has a mark at a predetermined position, the image sensor is arranged to be able to acquire the mark and image data around the mark, and the image processing unit includes: 3. The displacement value is obtained by detecting a mark position of a medium from the image data.
The scanning type drawing apparatus according to the above. 5. A pulse arranged at a position optically equivalent to the scanning line and scanned by a laser beam to generate a pulse having a cycle corresponding to the scanning speed, and transmitting the pulse to the control means. Further comprising: a monitor scale to perform; and a light branching unit that branches laser light emitted from the laser light source into drawing light for forming the scanning line and monitor light for scanning on the monitor scale. The control means converts the standby interval value to the number of standby interval pulses in correspondence with the pulses of the monitor scale, and then starts counting the pulses of the monitor scale from the scanning start end of the scanning line. The scanning type drawing according to any one of claims 1 to 4, wherein the optical modulator is controlled so as to start drawing after counting the number of pulses of a standby interval. Apparatus. 6. A loader for storing the medium and feeding the medium, and an unloader for winding the medium, wherein the medium extending between the loader and the unloader is provided on a drawing surface of the drawing table. The scanning type drawing apparatus according to any one of claims 1 to 5, wherein the loader and the unloader are arranged so as to be placed. 7. The control means causes the displacement value acquisition means to acquire the displacement value prior to drawing each time the medium is placed on the drawing surface of the drawing table, The scanning type drawing apparatus according to any one of claims 1 to 6, wherein the scanning type drawing apparatus is controlled so as to correct.