JPH10228115A - Laser plotter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance plotting actuation efficiency in accordance with the form of the entire image of a desired plotting pattern by shifting each plotting starting position of the partial plotting pattern so that the desired plotting pattern may be obtained based on the number of total bands when entire width is shorter than the length of the total bands. SOLUTION: A circuit pattern shown by a hatched area is recorded on a body to be plotted DS set on a plotting table 10. In the case of constituting the laser plotting device so that the entire pattern to be plotted may be obtained by synthesizing the partial plotting pattern based on N(N>=2) bands, the entire width of the pattern to be plotted in a main scanning direction is detected in advance. When the entire width is shorter than the length of (N-1) or more total bands, the plotting starting position is shifted so that the partial plotting pattern may be obtained based on the number of the total bands. Thus, the plotting efficiency to the entire pattern to be plotted is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to moving a workpiece in a sub-scanning direction while deflecting the laser beam in the main scanning direction with respect to the workpiece, and modulating the laser beam based on raster data. More specifically, the present invention relates to a laser writing apparatus for recording a desired drawing pattern on the object to be drawn, more specifically, the whole of the drawing pattern is partially recorded based on raster data of at least two bands, and The present invention relates to a laser writing apparatus configured to be obtained by synthesis.

[0002]

2. Description of the Related Art A laser drawing apparatus as described above is generally used for recording a fine drawing pattern on a surface of an appropriate object by using a laser beam. Examples of use include recording circuit patterns when manufacturing a printed circuit board using a photolithographic method, and the object to be drawn is, for example, a photosensitive film for a photomask or a photoresist layer on a substrate. I do.

In recent years, a series of processes from the process of designing a circuit pattern of a circuit board to the process of drawing the circuit have been integrated, and a laser writing apparatus plays a part of such a drawing integrated system. In other words, a CAD (Computer Aided) that designs circuit patterns and the like
Design) Station, CAM (Computer Aided Manufacturing) that edits drawing data (vector data) such as circuit patterns created by this CAD station.
A station or the like is provided, and the laser drawing apparatus functions as a peripheral device of the drawing integrated system.
In addition, the drawing integrated system is usually provided with a plurality of laser drawing devices, and the drawing integrated system is also provided with an engineering workstation (EWS) in order to control the overall control of the laser drawing devices.

[0004] The drawing vector data created by the CAD station or the drawing vector data edited by the CAM station is temporarily stored in a hard disk device provided in the EWS, and the drawing vector data is appropriately transferred from the EWS to the laser drawing device. . In a laser drawing device,
The drawing vector data is converted as drawing raster data,
A desired drawing pattern is recorded based on the drawing raster data. That is, in a laser writing apparatus, an object to be drawn such as a photosensitive film for a photomask or a photoresist layer on a substrate is scanned by a laser beam along a main scanning direction and sequentially moved in a sub-scanning direction. The modulation of the laser beam is performed in accordance with a clock pulse of a predetermined frequency based on the above-mentioned drawing raster data, whereby a desired drawing pattern is recorded on the drawing object.

In the above-described laser drawing apparatus, the size of a drawing pattern drawn in one drawing operation in the main scanning direction is determined by a drawing range or band in the main scanning direction. When recording a drawing pattern exceeding the range, a desired whole drawing pattern can be obtained by combining partial drawing patterns obtained by individual drawing operations. On the other hand, even if the size of the pattern drawn by the laser drawing apparatus in the main scanning direction is equal to or smaller than the drawing range in the main scanning direction, that is, the band, if the position of the drawing pattern with respect to the drawing object extends over two bands, Is performed twice to obtain the entire image of the drawing pattern by synthesizing the partial drawing patterns obtained by the individual drawing operations.

Conventionally, even when a completely blank area (that is, an area where no pattern is drawn) exists in the drawing area of a partial drawing pattern based on each band along the main scanning direction, In the completely blank area, a substantial drawing operation, that is, a drawing operation without drawing any pattern is performed, and such a drawing operation time is a wasteful time in terms of obtaining the drawing pattern itself.

[0007]

As is apparent from the above description, a conventional laser writing apparatus configured to be able to perform writing in a plurality of bands can obtain a large-sized drawing pattern. That the drawing operation must be performed, and that a useless drawing operation must be performed even in a completely blank area along the main scanning direction in the drawing area of the partial drawing pattern based on each band. Thus, it has been pointed out as a problem that the whole drawing operation time becomes relatively long.

Accordingly, it is an object of the present invention to provide a laser in which a desired drawing pattern as a whole is partially recorded based on raster data of at least two bands and is obtained by synthesizing those partial drawing patterns. An object of the present invention is to provide a drawing apparatus, which is configured to increase the drawing operation efficiency according to the form of the whole image of the desired drawing pattern.

[0009]

According to a first aspect of the present invention, there is provided a laser writing apparatus which deflects a laser beam in a main scanning direction with respect to an object to be drawn while moving the object in a sub-scanning direction. By moving and modulating the laser beam based on the raster data, a desired drawing pattern is recorded on the object to be drawn, and at this time, the drawing pattern is partially drawn based on at least two or more N bands. It is obtained by combining patterns. According to the first aspect of the present invention, in such a laser writing apparatus, the entire width of the desired writing pattern in the main scanning direction is detected in advance, and the total width of the total band of (N-1) or less is detected. When the length is shorter than the length, each drawing start position of the partial drawing pattern is shifted so that a desired drawing pattern is obtained based on the total number of bands.

In the laser writing apparatus according to a second aspect of the present invention, the object to be drawn is moved in the sub-scanning direction while the laser beam is deflected in the main scanning direction with respect to the object to be drawn, and the laser beam is Is modulated based on the raster data, so that a desired drawing pattern is recorded on the object to be drawn. According to the second aspect of the present invention, in such a laser writing apparatus, a complete blank area along the main scanning direction in the drawing pattern is detected in advance, and while the drawing by the laser beam reaches the complete blank area,
It is characterized in that the moving speed of the object to be drawn in the sub-scanning direction is increased.

In a laser writing apparatus according to a third aspect of the present invention, the object to be drawn is moved in the sub-scanning direction while the laser beam is deflected in the main scanning direction with respect to the object to be drawn, and Is modulated on the basis of the raster data, so that a desired drawing pattern is recorded on the object to be drawn. At this time, the drawing pattern is obtained by synthesizing a partial drawing pattern based on at least two or more N bands. It has become. According to the third aspect of the present invention, in such a laser writing apparatus, the entire width of the desired writing pattern in the main scanning direction is detected in advance, and the total width of the total band of (N-1) or less is detected. When the length is shorter than the length, the drawing start position of each of the partial drawing patterns is shifted so that a desired drawing pattern is obtained based on the total number of bands, and further, the main scanning in the partial drawing pattern based on each band is performed. A complete blank region along the direction is detected in advance, and the moving speed of the object to be drawn in the sub-scanning direction is increased while the drawing by the laser beam reaches the complete blank region.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a laser drawing apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 schematically shows a laser drawing apparatus according to the present invention as a perspective view. The laser drawing apparatus includes a drawing table 10, which is an XY table.
Mounted on a drive mechanism (not shown). On the drawing table 10, for example, a photosensitive film for a photomask or a substrate having a photoresist layer is conveyed by a suitable conveying means, for example, a belt conveyor or the like, as an object to be drawn. (Not shown).

The laser drawing apparatus has, for example, an argon laser generator 12 as a laser generating light source. A laser beam LB emitted from the argon laser generator 12 is deflected upward by a beam bender 14. On the upper side of the drawing table 10, a fixed table plate 16 supported by a suitable support structure (not shown) is arranged, on which various optical elements are installed.
The laser beam LB is guided on the drawing table 10 as a scanning laser beam by these optical elements. In the present embodiment, the argon laser generator 12 is of a water-cooled type, for example, its output is 2.5 W, and its laser wavelength is 488 nm.

The fixed table plate 16 includes a beam bender 18.
The beam bender 18 is provided with the beam bender 14.
After receiving the laser beam LB from the laser beam, the laser beam LB is reflected toward the beam splitter 20. The laser beam LB is split into two laser beams LB1 and LB2 by a beam splitter 20, the laser beam LB1 is directed to a beam separator 26 via beam benders 22 and 24, and the laser beam LB2 is converted to beam benders 28 and 30.
And 32 to a beam separator 34.

The beam separator 26 has a laser beam LB
1 is divided into eight parallel laser beams. Similarly, the beam separator 34 also divides the laser beam LB2 into eight parallel laser beams. The eight parallel laser beams from the beam separator 26 are guided to an electronic shutter 40 by beam benders 36 and 38, and the beam separator 34
Are guided to an electronic shutter 46 by beam benders 42 and 44.

Each of the electronic shutters 40 and 46 includes eight acousto-optic elements and a driving circuit for the acousto-optic elements, and each acousto-optic element is assigned a corresponding one of the eight laser beams. The eight laser beams having passed through the electronic shutter 40 are made incident on the light combiner 48, while the eight laser beams having passed through the electronic shutter 46 are also made incident on the light combiner 48 via the beam bender 50. The light combiner 48 can be configured as, for example, a polarizing beam splitter. The eight laser beams that have passed through the electronic shutters 40 and 46 are combined into 16 laser beams by the light combiner, that is, the polarizing beam splitter 48. The 16 laser beams are supplied by beam benders 52, 5
The light is made incident on the polygon mirror 58 through 4 and 56, and is deflected along the main scanning direction by the respective rotating reflection surfaces.

The 16 laser beams deflected along the main scanning direction by the respective rotating reflection surfaces of the polygon mirror 58 are first passed through the fθ lens 60, and then directed toward the drawing table 10 by the turning mirror 62. The drawing table 1 later passes through the condenser lens 64
0 is reached. In short, the object to be drawn placed on the drawing table 10 is scanned by the sixteen deflecting laser beams deflected in the main scanning direction by the respective rotating reflection surfaces of the polygon mirror 58.

As shown in FIG. 1, an XY coordinate system which is immovable with respect to the machine frame of the laser writing apparatus is set on the moving plane of the drawing table 10, and the X axis of the XY coordinate system is in the sub-scanning direction. , And its Y axis extends in the main scanning direction. During the drawing operation, the 16 laser beams are deflected in the positive direction of the Y-axis (main scanning direction).
0 is moved in the negative direction of the X-axis (that is, in the sub-scanning direction).

When the drawing surface of the object to be drawn placed on the drawing table 10 is scanned at a time (main scanning direction) by 16 scanning laser beams deflected by the respective rotating reflection surfaces of the polygon mirror 58, Each electronic shutter 40, 46
Are operated in accordance with a clock pulse of a predetermined frequency based on the drawing raster data, whereby 16 scanning laser beams are modulated based on the drawing raster data. On the other hand, while the 16 scanning laser beams are deflected along the main scanning direction, the drawing table 10 is sequentially moved along the sub-scanning direction, and the deflection along the main scanning direction by the 16 scanning laser beams is reduced. When the processing is completed, the moving distance of the drawing table 10 is a distance corresponding to the width of the 16 scanning laser beams in the sub-scanning direction. Thus, by repeatedly deflecting the 16 scanning laser beams in the main scanning direction, the drawing patterns are sequentially recorded on the drawing surface on the drawing object.

By the way, when the 16 scanning laser beams are deflected in the direction perpendicular to the sub-scanning direction, that is, in the main scanning direction during the drawing operation, the drawing line along the main scanning direction by the 16 scanning laser beams is assumed. Is inclined with respect to the sub-scanning direction. Because, as mentioned above, 16
This is because the drawing table 10 is sequentially moved at a predetermined speed along the sub-scanning direction while the scanning laser beam is deflected along the main scanning direction. However, in practice, the deflection direction of the 16 scanning laser beams is X
Since the pixels are tilted by a predetermined angle with respect to the axial direction in advance, the drawing pixels included in each of the drawing lines by the 16 scanning laser beams, that is, the drawing dots are perpendicular to the sub-scanning direction. Will be arranged.

FIG. 2 is a control block diagram of the laser writing apparatus shown in FIG. 1. As shown in FIG. 2, the laser writing apparatus is connected to an engineering work station (EWS) 66 which controls the writing operation. Connected. E
The WS 66 is provided with a host controller 68, which is, for example, a central processing unit (CP).
U) and other microprocessors and memories (ROM, RA
M) and the like.

As shown in FIG. 2, the EWS 66 is provided with a keyboard 70 through which various command signals for controlling the overall operation of the laser drawing apparatus and data necessary for the control are provided. Host controller 6
8 is input. Also, a hard disk device 72 is connected to the host controller 68, and the hard disk device 72 is used for storing drawing vector data transferred from the CAD station or the CAM station to the EWS 66. Further, the host controller 68
Is connected to a CRT display device 74. When the CRT display device 74 performs necessary processing on the drawing vector data before drawing, the drawing vector data is expanded and displayed as a drawing pattern.

As is apparent from FIG. 2, the laser writing apparatus is provided with a system controller 76. Like the host controller 68, the system controller 76 has a microprocessor such as a central processing unit (CPU) and memories (ROM, RAM). ) And the like. The system controller 76 is LA
It is connected to the host controller 68 of the EWS 66 via the N interface circuit 78, and various command signals are exchanged between them. The laser drawing device is provided with a buffer memory 80, in which the drawing vector data read from the hard disk device 72 of the EWS 66 is transmitted from the host controller 66 to the LAN.
The data is transferred via the interface circuit 78.

As shown in FIG. 2, the system controller 76 controls the operation of the main scanning control circuit 82. The main scanning control circuit 82 is provided with the above-mentioned electronic shutters 40 and 46. The main scanning control circuit 82 is provided with a synchronizing circuit 84, and the electronic shutters 40 and 46 are driven by a control voltage signal output from the synchronizing circuit 84.
6 is created based on the raster data output from.
The drawing data processing circuit 86 is supplied with drawing vector data that is appropriately read from the buffer memory 80.

Referring to FIG. 3, the drawing data processing circuit 8
6, a drawing data processing circuit 86 is provided with a raster conversion circuit 86A, and the drawing vector data read from the buffer memory 80 is converted by the raster data conversion circuit 86A. Converted to drawing raster data. The writing of the drawing vector data in the buffer memory 80 and the reading of the drawing vector data therefrom are performed by a write clock pulse and a read clock pulse output from the system controller 76.

The drawing data processing circuit 86 includes a first bitmap memory 86B and a second bitmap memory 86.
C are provided in parallel.
And 86C have the same storage capacity. Also,
The drawing data processing circuit 86 includes a first switch circuit 86D.
And a second switch circuit 86E. The first switch circuit 86D is connected to an input terminal connected to the raster conversion circuit 86A and to respective input terminals of the first and second bitmap memories 86B and 86C. The second switch circuit 86E has an input terminal connected to each output terminal of the first and second bitmap memories 86B and 86C, and an output terminal connected to the synchronization circuit 84. Prepare.

As described above, the drawing vector data is sequentially read from the buffer memory 80, and the drawing vector data is converted into the drawing raster data by the raster conversion circuit 86A. The drawing raster data is sequentially output from the raster conversion circuit 86A to the first switch circuit 86D, and is alternately written to the first and second bitmap memories 86B and 86C by the switching operation of the first switch circuit 86D. . The drawing raster data alternately written and stored in the first and second bitmap memories 86B and 86C are alternately read out by the switching operation of the second switch circuit 86E and output to the synchronization circuit 84. Is done.

The first bitmap memory 86B and the second bitmap memory 86B
When the reading of the raster data from one of the bitmap memories is completed after the reading of the raster data from one of the bitmap memories 86C is completed, the data is transferred to the other bitmap memory. Of the raster data is started. By alternately writing the raster data to the two bitmap memories 86B and 86C, and alternately reading the raster data from the bitmap memories,
A large amount of drawing raster data converted from drawing vector data can be sequentially transmitted to the synchronization circuit 84.

First and second switch circuits 86D and 86
The switching operation of 6E is controlled by the system controller 76 at a predetermined timing, and writing and reading of raster data to and from each bit map memory 86B, 86C is performed by a write clock pulse and a read clock pulse output from the system controller 76. Will be Reading of the drawing raster data from each of the bitmap memories 86B and 86C is performed by 16 bits.
These 16-bit raster data are included in each of the 16 consecutive drawing lines in the main scanning direction.

On the other hand, a clock pulse having a predetermined frequency is output from the system controller 76 to the synchronization circuit 84.
Based on this clock pulse, a control voltage signal is output from the synchronizing circuit 84 to the respective driving circuits of the total of 16 acousto-optical elements of the electronic shutters 40 and 46. Thus, the 16 laser beams deflected by the polygon mirror 58 are modulated by the electronic shutters 40 and 46 based on the 16-bit raster data output from the synchronization circuit 84.

More specifically, when each of the control voltage signals output from the synchronization circuit 84 is input to each drive circuit of the acousto-optic element included in the electronic shutter 40,
A high frequency drive voltage is output from each drive circuit to the corresponding acousto-optic element and applied. The voltage level of the control voltage signal output to each drive circuit is changed based on the corresponding raster data, and accordingly, the level of the high-frequency drive voltage output from each drive circuit to the corresponding acousto-optic element Is also changed, thereby changing the diffraction direction of the laser beam passing through each acousto-optic element. That is,
When the raster data pixel is a color pixel (ie, “1” as digital pixel data), the laser beam is diffracted toward the light combiner 48 and the raster data pixel is a non-color pixel (ie, digital pixel). When the data is “0”), the laser beam is diffracted out of the light combiner 48.

Similarly, the control voltage signal output from the synchronizing circuit 84 is also input to each drive circuit of the acousto-optic element included in the electronic shutter 46. At this time, the drive circuit of each acousto-optic element outputs a high-frequency drive voltage. Is output and applied to the corresponding acousto-optic element, and the level of the high-frequency driving voltage is changed based on the corresponding raster data. In the case of the electronic shutter 46, the pixels of the raster data are colored pixels (that is, "1" as digital pixel data).
When the laser beam is diffracted toward the beam bender 50 and is incident on the photosynthesizer 48, and when the pixel of the raster data is a colorless pixel (ie, “0” as digital pixel data), The laser beam is diffracted off the beam bender 50.

In short, only when the pixel of the raster data is a coloring pixel, the corresponding laser beam is
, And is directed to the polygon mirror 58, and dots are recorded as coloring pixels on the object to be drawn on the drawing table 10. Accordingly, by modulating each laser beam by the respective electronic shutters 40 and 46 based on the corresponding raster data as described above, a drawing pattern based on the raster data is recorded on the drawing target on the drawing table 10. Will be.

Returning to FIG. 2, the main scanning control circuit 82 includes a Y scale sensor 88 as shown in FIG.
And a signal processing circuit 90. The Y scale sensor 88 measures and detects the deflection distance of the laser beam along the main scanning direction (Y axis), and is a well-known one. At the time of the drawing operation, the output signal from the Y scale sensor 88 is appropriately processed by the signal processing circuit 90 and then sent to the system controller 76. Based on the signal, a clock pulse having a predetermined frequency to be output to the synchronization circuit 84 is created.

In the block diagram of FIG.
Indicates a control circuit of the XY drive mechanism described above. The XY drive mechanism control circuit 92 includes a sub-scanning control circuit 94. The sub-scanning control circuit 94 has an X-axis servo motor 96 for moving the drawing table 10 along the X-axis direction (sub-scanning direction), and an X-axis servo motor for outputting a drive pulse to the X-axis servo motor 96. A drive circuit 98 is provided.
The X-axis drive circuit 98 outputs a drive pulse for the X-axis servo motor 96 based on a drive control clock pulse output from the system controller 76.

The sub-scanning control circuit 94 is provided with an X-scale sensor 100 and a signal processing circuit 102. The X-scale sensor 100 moves the relative movement distance of the 16 laser beams in the sub-scanning direction, that is, of the drawing table 10. This is to measure and detect the moving distance along the X-axis direction, and is itself known. At the time of drawing operation, an output signal from the X scale sensor 100 is sent to the system controller 76 after being appropriately processed by the signal processing circuit 102,
Based on this, a drive control clock pulse to be output to the X-axis drive circuit 98 is created.

The XY drive mechanism control circuit 92 further includes a Y-axis servomotor 104 for moving the drawing table 10 in the Y-axis direction (main scanning direction), and a drive pulse to the Y-axis servomotor 104. And a Y-axis drive circuit 106 for outputting the Y-axis servo motor 104 based on a drive control clock pulse output from the system controller 76. .

Next, the operation principle of the laser writing apparatus according to one aspect of the present invention will be described with reference to FIGS.

First, referring to FIG. 4, the drawing table 1
An example in which a circuit pattern as indicated by a shaded area is recorded on a drawing target object DS (for example, a photosensitive film for a photomask or a photoresist layer on a substrate) placed on the substrate 0 is schematically shown. In this example, the laser writing apparatus is configured such that such a circuit pattern (shaded area) is obtained by combining partial drawing patterns based on three bands, that is, a first band, a second band, and a third band. During the drawing operation of the partial drawing pattern in each band, the 16 laser beams are deflected in the main scanning direction (positive side of the Y axis) and the drawing table 10 is moved in the sub scanning direction (negative side of the X axis).
It is moved to. In FIG. 4, the first band, the second band
The drawing start position along the main scanning direction in each of the band and the third band is represented by Y _(a) , Y as coordinate data on the Y axis.
_(b) and Y _(c) . As is apparent from FIG. 4, in the present example, the width of the entire circuit pattern in the main scanning direction is substantially equal to the total length of the first band, the second band, and the third band. Therefore, a drawing operation based on each band, that is, a drawing operation for three bands must be executed.

On the other hand, FIG. 5 also shows a schematic diagram similar to FIG. 4. In this example as well, the entire circuit pattern (shaded area) is the first circuit pattern.
Although the band extends over the band, the second band, and the third band, the width of the entire circuit pattern in the main scanning direction is equal to or less than the total length of the two bands. Conventionally, in order to obtain the entire circuit pattern shown in FIG. 5, similarly to the case of the example of FIG. 4, the drawing operation based on each of the first band, the second band, and the third band, that is, for three bands, A drawing operation is required.

However, according to the present invention, as shown in FIG. 5, the first shift band and the second shift band are set, so that the drawing operation based on each shift band, that is, the drawing operation for two bands is performed. The circuit pattern (shaded area) shown in FIG. In FIG. 5, the drawing start position along the main scanning direction in each of the first shift band and the second shift band is represented by Y _{(a ′)} and Y _{(b ′)} as coordinate data on the Y axis. It is shown.

FIG. 6 is a schematic diagram similar to FIG. 4. In this example, the entire circuit pattern (shaded area) is the first pattern.
Although the band extends over the band and the second band, the width of the entire circuit pattern in the main scanning direction is equal to or less than the length of one band. Conventionally, in order to obtain the entire circuit pattern shown in FIG. 6, a drawing operation based on each of the first band and the second band, that is, a drawing operation for two bands is required.

However, according to the present invention, since the shift band is set as shown in FIG. 6, the drawing operation based on the shift band, that is, the drawing operation for one band is performed only by performing the whole band shown in FIG. Circuit pattern (shaded area)
Is obtained. In FIG. 6, the drawing start position of the shift band along the main scanning direction is indicated by Y _{(a ″)} as coordinate data on the Y axis.

In short, according to the present invention, when the laser writing apparatus is configured such that the entire pattern to be drawn can be obtained by synthesizing a partial drawing pattern based on at least two or more N bands. The entire width of the pattern to be drawn in the main scanning direction is detected in advance, and when the total width is shorter than the length of the total band of (N-1) or less, a partial drawing pattern is obtained based on the number of the total bands. The drawing start position is shifted as described above, whereby the drawing efficiency of the entire drawing pattern can be increased.

Next, the principle of operation of the laser writing apparatus according to another aspect of the present invention will be further described with reference to FIGS.

FIGS. 7, 8 and 9 show the first embodiment shown in FIG.
A partial drawing pattern obtained by a drawing operation based on each of the band, the second band, and the third band is shown. As shown in each drawing, the partial drawing pattern based on each band may include a complete blank area along the main scanning direction.
According to the present invention, the complete blank area is detected before the drawing operation, and the blank area start position data X _i and the blank area end position data X _j along the sub-scanning direction of the complete blank area are detected.
Is created. While the drawing by the laser beam extends over the complete blank area, the moving speed of the drawing target object DS, that is, the drawing table 10 in the sub-scanning direction is increased, thereby increasing the efficiency of the drawing operation.

It is necessary to detect the complete blank area as described above for an area in which the width of the complete blank area in the sub-scanning direction is a predetermined length or more. That is, when accelerating or decelerating the drawing table 10 having a considerable mass, a certain acceleration / deceleration distance is required, and a complete blank having a width equal to or less than the acceleration / deceleration distance is required. This is because it is meaningless to advance the drawing table 10 in the sub-scanning direction between the areas.

In a preferred embodiment of the laser drawing apparatus according to the present invention, the drawing unit in the sub-scanning direction of the drawing unit drawn by the raster data stored and held in the first and second bitmap memories 86B and 86C, respectively. A complete blank area larger than the width is detected, and the feeding of the drawing table 10 is accelerated between the complete blank areas. About this, FIG.
It will be described in detail with reference to FIG.

FIG. 10 shows a partial drawing pattern of the first band shown in FIG. 7 in a partially enlarged manner. In FIG. 10, _Pn denotes first and second bitmap memories 86B and 86C. Indicates the width in the sub-scanning direction of the drawing unit drawn by the raster data stored and held in each of the above, and such a width is usually called a partition in the technical field. Each partition _Pn includes a predetermined number (PL) of drawing lines in the main scanning direction, and such a number may be, for example, 512. That is, the first
Each of the second bitmap memories 86B and 86C is provided with a capacity capable of storing raster data corresponding to 512 drawing lines in the main scanning direction. Assuming that the size of a pixel or dot to be drawn by the laser beam is 5 μm, the length of each partition in the sub-scanning direction is 2.56 (512 * 0.005) mm. In short, in the preferred embodiment of the laser writing apparatus according to the present invention, a complete blank area having a width of 2.56 mm or more along the sub-scanning direction is detected.

When a complete blank area is detected, start position data X _i and end position data X _{j of} the complete blank area are created, and these data X _i and X _j are drawn in the main scanning direction drawing line included in the first band. To 0, 1, 2, 3,...
Is the number data at the time of numbering. Note that FIG.
In FIG. 10, the number of the first drawing line in the main scanning direction included in each partition _Pn is n * P
L, and at the time of drawing operation, drawing of each partition is obtained by 32 (512/16) scanning operations.

Next, referring to the flowcharts shown in FIGS. 11 and 12, the EWS of the laser writing apparatus according to the present invention will be described.
The vector data processing routine executed at 66 will be described.

At step 1101, predetermined drawing vector data is read from the hard disk device 72,
It is developed and displayed on the display screen of the T display device 74.
Next, in step 1102, Y of the drawing vector data
The minimum coordinate data Y _MIN on the axis is detected, and subsequently, in step 1103, the maximum coordinate data Y _MAX on the Y axis of the drawing vector data is detected.

In step 1104, the following operation is performed. ΔY ← Y _MAX - Y _MIN i.e., the width in the main scanning direction of the drawing pattern of the entire obtained from the drawing vector data (Y axis) are obtained.

Next, in step 1105, it is determined whether or not ΔY is larger than the maximum drawing length along the main scanning direction, that is, the maximum band length B _MAX obtained by one drawing operation of the laser drawing apparatus. If ΔY> B _MAX , proceed to step 1106, where ΔY is the maximum band length B _MAX of 2
It is determined whether the length is greater than the double length. If ΔY>
If it is 2B _MAX , the process proceeds to step 1107, where the first band, the second band, and the third band as shown in FIG. 4 are set.

On the other hand, in step 1106, if Δ
If Y ≦ 2B _MAX , the process proceeds to step 1108, where the first shift band and the second shift band as shown in FIG. 5 are set. If it is determined in step 1105 that ΔY ≦ B _MAX , the process proceeds to step 1109, where a single shift band as shown in FIG. 6 is set.

When the band setting is completed in any of steps 1107, 1108 and 1109, the process proceeds to step 1110, where the vector data for each band is filed. Next, step 111
The process then proceeds to step 1, where the drawing start position data of each band along the main scanning direction is created and stored in the RAM of the host controller 68 of the EWS 66. For example, when the first band, the second band, and the third band as shown in FIG. 4 are set in step 1107, Y _(a) , Y _(b), and Y _(c) are used as the drawing start position data. When the first shift band and the second shift band as shown in FIG. 5 are set in step 1108, Y _{(a ′)} and Y _{(b ′)} are created as the drawing start position data. When a single shift band as shown in FIG. 6 is set in step 1109, Y _{(a ″)} is used as the drawing start position data.
Is created.

At step 1112, the drawing start position data (Y _(a) , Y (Y _)
(b) , Y _(c) ; Y _{(a ')} , Y _(b') ; Y _{(a '')} ) are EWS6
6 is transmitted to the laser writing apparatus, and the writing start position data is stored in the R of the system controller 76 of the laser writing apparatus.
Stored in AM. When the transmission of the drawing start position data is completed in step 1112, the process proceeds to step 1113, where a complete blank area in the main scanning direction is detected for the drawing pattern of the relevant band. As described above, an area detected as a complete blank area is equal to or larger than the width of the partition (P _n ).

In step 1114, it is determined whether or not a completely blank area has been detected from the above-described drawing pattern.
When a complete blank area is detected, the process proceeds to step 1115, where a complete start of the blank area position data X _i and end position data X _j is transmitted is created in the laser drawing apparatus, they start position data X _i and the end position The data X _j is stored in the RAM of the system controller 76. On the other hand, when a complete blank area is not detected in step 1114, the process proceeds to step 1116, where a signal indicating that there is no blank area is transmitted to the laser drawing apparatus, and the signal is stored in the RAM of the system controller 76.

In step 1117, it is determined whether or not a drawing operation preparation completion signal has been received from the laser drawing apparatus. If the reception of the drawing operation preparation completion signal is confirmed, the process proceeds to step 1118, where the drawing vector data of the corresponding band is transmitted from the EWS 66 to the laser drawing device. Next, the process proceeds to step 1119, where a drawing operation start command signal is transmitted from the EWS 66 to the laser drawing device.

In step 1120, it is determined whether or not there is a next band to be drawn. If there is a next band to be drawn, steps 1120 to 11
Returning to 12, the routine consisting of steps 1112 to 1120 is repeated. On the other hand, if there is no next band to be drawn, the process proceeds to step 1121, where a drawing operation stop command signal is transmitted from the EWS 66 to the laser drawing apparatus. After transmitting the drawing operation stop command signal, the vector data processing routine ends.

Next, a drawing operation routine executed on the side of the laser drawing apparatus will be described with reference to the flowchart shown in FIG.

At step 1301, the drawing start position data (Y _(a) , Y _(b) , Y _{(c) ) of} the corresponding band to be drawn;
It is determined whether or not Y _{(a ′)} , Y _{(b ′)} ; Y _{(a ″)} ) has been received from the EWS 66. When the reception of the drawing start position data of the corresponding band is confirmed, the process proceeds to step 1302, where it is determined whether a signal indicating that there is no blank area is received from the EWS 66. If the signal indicating that there is no blank area is not received, the process proceeds to step 1303, where the start position data X _i and the end position data X X of the complete blank area are received.
_It is determined whether _j has been received from EWS 66 or not.

If the reception of the start position data X _i and the end position data X _j of the complete blank area is confirmed without receiving a signal indicating that there is no blank area, the process proceeds to step 1304, and
Therefore, the flag CF is set to “0”. Next, in step 1305, a raster conversion flag setting routine as shown in FIG. 14 is executed, and when the execution of this raster conversion flag setting routine is completed, the process proceeds to step 1306,
Then, the drawing operation preparation completion signal is sent from the laser drawing device to the EW.
It is transmitted to S66. On the other hand, in step 1302, if the reception of the signal indicating that there is no blank area is confirmed, the process proceeds from step 1302 to step 1307,
Then, after setting the flag CF to "1", the process proceeds to step 13
In step 06, a writing operation preparation completion signal is transmitted from the laser writing apparatus to the EWS 66.

In step 1308, it is determined whether a drawing operation start command signal has been received from the EWS 66. When the reception of the drawing operation start command signal is confirmed, step 1
At 309, it is determined whether the flag CF is set to "0". If CF = 0, that is, if a complete blank area is included in the drawing pattern of the corresponding vector data to be drawn, the process proceeds to step 1310, where the drawing routine according to the present invention, that is, FIGS.
The drawing routine shown in FIG. On the other hand, in step 1309, when CF = 1, that is, when the complete blank area is not included in the drawing pattern of the corresponding vector data to be drawn, steps 1309 to 1
Proceeding to step 311, a normal drawing routine is executed.

In any case, when the drawing routine is executed, the process proceeds to step 1312, where it is determined whether or not the drawing based on the corresponding vector data has been completed. Then, it is determined whether a drawing operation stop signal is received from the EWS 66 or not. If the drawing operation stop signal has not been received, the process returns from step 1313 to step 1301, and the same drawing operation routine is repeated. On the other hand, when the reception of the drawing operation stop signal is confirmed in step 1313, this drawing operation routine ends.

Next, the raster conversion flag setting routine executed in step 1305 of FIG. 13 will be described with reference to the flowchart of FIG.

At step 1401, the counters n, i and j are reset, and then the routine proceeds to step 1402,
Therefore, the start position data X _{(i = 0)} of the complete blank area is
It is determined whether or not the drawing line matches the first drawing line in the main scanning direction included in the second partition P _{(n = 0)} (X _{(i = 0)} = 0 * PL = 0). The start position data X _{(i = 0)} of the complete blank area is the 0th partition P _{(n = 0)}
, When the 0th partition P _{(n = 0)} is a completely blank area, the process proceeds to step 1403, where the 0th partition P _{( The} raster conversion flag F _{(n = 0)} corresponding to _{(n = 0)} is set to “0”.

At this point, since it is confirmed in step 1402 that the start position data X _{(i = 0)} of the complete blank area is in the 0th partition P _{(n = 0)} ,
In step 1404, the count of the counter i is incremented by "1", and then the process proceeds to step 1405, where the count of the counter n is incremented by "1".

On the other hand, in step 1402, X
_{When (i = 0)} ≠ 0 * PL ≠ 0, the 0th partition P _{(n = 0)} includes at least a part of the drawing pattern, that is, the 0th partition P _{Since (n = 0)} does not become a complete blank area, the process proceeds from step 1402 to step 1406, where the 0th
The raster conversion flag F _{(n = 0)} corresponding to the partition P _{(n = 0)} is set to “1”.

In step 1407, the start position data X _{(i = 0)} of the complete blank area is stored in the 0th partition P
_It is determined whether or not it matches the main scanning direction drawing line included in _{(n = 0)} (excluding the first main scanning direction drawing line) (0 * PL = 0 <X _{(i = 0)} <1 * PL = 512). If 0
<X _{(i = 0)} <512, that is, the start position data X _{(i = 0)} of the complete blank area is the 0th partition P
If it is confirmed that it is within _{(n = 0)} , step 1
407 proceeds to step 1404, where the counter i
Is incremented by "1".

On the other hand, in step 1407, X
_{(i = 0)} ≧ 512, that is, the start position data X _{(i = 0)} of the complete blank area is the 0th partition P _{(n = 0)}
If not included in step 1, steps 1407 to 1
Proceeding to 408, where the count number of the counter n is "1"
, And then return from step 1408 to step 1402.

In any case, when the partition _Pn including the drawing line in the main scanning direction that matches the start position data X _{(i = 0) of} the complete blank area is confirmed, step 1404 is executed.
And step 1405 via step 1405,
Therefore, the end position data X _{(j = 0)} of the complete blank area is
It is determined whether or not the data is included in the _n th partition P _n (n * PL ≦ X _{(j = 0)} <(n + 1) * P
L).

If it is determined in step 1409 that the end position data X _{(j = 0)} of the complete blank area is not included in the n-th partition P _n ,
Since the n-th partition P _n is a completely blank area, steps 1409 to 1410
Advances to, where said n-th partition P _n raster conversion flag F _n corresponding to is set to "0". Next, the routine proceeds to step 1411, where the count of the counter n is counted up by "1".
The process returns from step 11 to step 1409. That is, all the way to partition P _n that includes a main scanning direction drawing line end that matches the position data X _{(j = 0)} of the blank area is confirmed, it earlier partition P _n raster conversion flag F _n corresponding to " 0 ".

[0075] In step 1409, if the full blank area end position data X _{(j = 0)} is determined to be included in the n-th partition P _n is the the n-th partition P _n Since at least a part of the pattern to be drawn is included, that is, the n-th partition P _n does not become a completely blank area, the process proceeds from step 1409 to step 1412, where the n-th partition P _n raster conversion flag F _n corresponding to is set to "1".

At this point, since the partition _Pn including the drawing line in the main scanning direction that matches the end position data X _{(j = 0)} of the complete blank area has been confirmed in step 1409, the count of the counter j is determined in step 1413. The number is counted up by "1", and then step 141
The process proceeds to step 4, where the count of the counter n is incremented by "1".

At step 1415, it is determined whether or not the count number of the counter j has exceeded its maximum value ("4" in the example of FIG. 7). If the count of the counter j does not exceed the maximum value, the process returns from step 1415 to step 1402, and the routine including steps 1402 to 1415 is repeated.

At step 1415, when it is confirmed that the count number of the counter j has exceeded the maximum value,
Proceeds from step 1415 to step 1416, where the n-th partition P _n raster conversion flag F _n corresponding to the set to "1", the program proceeds to step 1417, where the counter n counts is incremented by "1" Is done.

In step 1418, it is determined whether or not the count number of the counter n has exceeded its maximum value. If the count number of the counter n does not exceed the maximum value, the process returns from step 1418 to step 1416, and the routine including steps 1416 to 1418 is repeated. That is, since not included in the position data X _j position data X _i and end beginning of the complete blank area on any of the remaining partitions P _n after the present time, the raster conversion corresponding to, respectively, respectively the remaining partitions P _n All the flags _Fn are set to "1".

As is apparent from the above description, by executing the raster conversion flag setting routine shown in FIG. 14, it is determined whether or not each of the partitions _Pn is a completely blank area. the raster conversion flag F _n corresponding to the partition P _n that a blank area is set to "0" is set to "1" in the raster conversion flag F _n corresponding to the partition P _n that do not completely blank region Will be.

In step 1418, when the count number of the counter n exceeds the maximum value, the raster conversion flag setting routine ends, and the process returns to step 1306 of the drawing operation routine shown in FIG.

Subsequently, referring to the flowcharts shown in FIGS. 15 and 16, a drawing routine according to the present invention (FIG. 13)
Step 1310) will be described.

In step 1501, by operating the XY drive mechanism control circuit 92, the drawing table 10 is positioned at the drive start position. Then, step 150
In 2, the drawing start origin is set on the X scale, and this drawing start origin corresponds to the drawing start position on the drawing table 10 along the sub-scanning direction.

[0084] At step 1503, the acceleration / deceleration setting routine shown in FIG. 17 is executed, where the acceleration start position data SX _i and deceleration end position data SX _j is created. Acceleration starting position data SX _i and deceleration end position data SX _j are those obtained on the basis of the position data X _j beginning position data X _i and the end of each complete blank area.

[0085] That is, the acceleration start position data SX _i main scan that matches the start position data X _i of a complete blank area in 16 of 16 when the sub-scanning direction of the drawing scanned by the laser beam main scanning direction drawing line When the direction drawing line is included, the drawing position of the last main scanning direction drawing line of the 16 main scanning direction drawing lines is represented as a distance from the drawing start position in the sub-scanning direction, deceleration end position data SX _j also includes a main scanning direction drawing lines matching the end data X _j of the complete blank area in the 16 laser beams by the 16 during sub-scanning direction of the drawing scanning the main scanning direction drawing line 16 lines immediately before the 16 lines in the main scanning direction
The drawing position of the last main scanning direction drawing line among the main scanning direction drawing lines is represented as a distance from the drawing start position in the sub-scanning direction.

[0086] In step 1503, the creation of acceleration starting position data SX _i and deceleration end position data SX _j is completed, the process proceeds to step 1504, where the counter n
Is reset, and then at step 1505, the flag F
1 and F2 are each set to “1”. Subsequently, in step 1506, execution of a raster conversion interrupt routine as shown in FIG. 20 is instructed. By execution of the raster conversion interrupt routine, vector data for one partition is converted into raster data, and the first bitmap memory is converted. 8
6B and the second bitmap memory 86C are alternately written. However, the conversion to raster data is not performed for the vector data of the partition which becomes a completely blank area.

The raster conversion interrupt routine shown in FIG. 20 is executed independently of the drawing routine shown in FIGS.
Reset and flags F1 and F2 in step 1505
The setting of "1" is necessary for executing the raster conversion interrupt routine of FIG.

At step 1507, it is determined whether or not the writing of the raster data to the first bitmap memory 86B is completed. When the completion of the writing of the raster data to the first bitmap memory 86B is confirmed, Step 1
Proceeding to 508, where counters i and j are reset, respectively. In step 1509, the sub-scanning control circuit 9
The drawing table 10 is moved from the driving start position by the operation of 4 and accelerated to a predetermined feeding speed at the time of the drawing operation, and then proceeds to step 1510, where it is determined whether the drawing table 10 has reached the drawing start position. Is done.

If it is confirmed in step 1510 that the drawing table 10 has reached the drawing start position, step 1
The process proceeds to 511, where it is determined whether or not the acceleration start position data SX _{(i = 0)} matches the drawing start origin. When the acceleration start position data SX _{(i = 0)} matches the drawing start origin,
That is, when SX _{(i = 0)} = 0, the routine proceeds to step 1512, where the drawing table 10 is accelerated to twice the feed speed during the drawing operation.

In step 1513, output data is sampled from the X-scale sensor 100, and based on the output data, the X-scale drawing start origin (step 1)
The distance data FD from 502) is calculated, and then the routine proceeds to step 1514, where it is determined whether or not the distance data FD is equal to a value obtained by subtracting a predetermined numerical value α from the deceleration end position data SX _{(j = 0).} . If FD ≠ (SX _{(j = 0)} −
If α), the process returns to step 1513. In short, until the distance data FD becomes equal to (SX _{(j = 0)} -α)
The routine consisting of steps 1513 and 1514 is repeated. The sampling of the output data from the X scale sensor 100 is performed at appropriate time intervals.

At step 1514, FD = (SX
_{When (j = 0)} −α), the process proceeds to step 1515, where the feed speed of the drawing table 10 is reduced to the feed speed during the drawing operation. The numerical value α is a moving distance of the drawing table 10 required for smoothly reducing the feed speed of the drawing table 10 to the feed speed at the time of the drawing operation. The moving distance is, for example, 16 b. The distance (0.4 mm) can be set so that the drawing table 10 can be moved between five drawing scans by the laser beam.

At step 1516, the output data from the X-scale sensor 100 is sampled, the distance data FD from the X-scale drawing start origin is calculated based on the output data, and then the process proceeds to step 1517.
Therefore, the distance data FD is the deceleration end position data SX _{(j = 0)}
Is determined. If FD ≠ SX _{(j = 0)} , the flow returns to step 1516. That is, the distance data F
The routine consisting of steps 1516 and 1517 is repeated until D equals SX _{(j = 0)} . Note that X
Steps 1513 and 1514 relate to the time interval for sampling the output data from the scale sensor 100.
It is the same as the case where the routine consisting of is repeated.

In step 1517, FD = SX
_{When (j = 0)} , the routine proceeds to step 1518, where the counts of the counters i and j are counted up by "1", and then the routine proceeds to step 1519, where a drawing operation by 16 laser beams is executed. .

On the other hand, when the acceleration start position data SX _{(i = 0)} does not coincide with the drawing start origin in step 1511, that is, when SX _{(i = 0)} ≠ 0, step 1511
Then, the process proceeds to step 1519, where a drawing operation using 16 laser beams is immediately executed.

At step 1520, it is determined whether or not the count number of the counter i or j is equal to or less than the maximum value. If the count value of the counter i or j is equal to or less than the maximum value, the process proceeds from step 1520 to step 1521, where the output data is sampled from the X scale sensor 100, and based on the output data, the X scale is drawn from the drawing start origin. distance data FD is calculated, and then proceeds to step 1522, where the distance data FD whether equal to the acceleration start position data SX _i is determined.
If it is FD ≠ SX _i, returns to step 1521.
That is, the distance data FD is to equal the SX _i, are repeated routine consisting of steps 1521 and 1522. Note that the time interval for sampling the output data from the X scale sensor 100 is described in step 151.
This is similar to the case where the routine consisting of 3 and 1514 is repeated.

At step 1522, the distance data F
When D is equal to the acceleration start position data SX _i, the process proceeds to step 1523, where 16 of the execution of the drawing operation by the laser beam is stopped, then the step 15
23 returns to step 1512. That is, step 15
The routine consisting of steps 1512 to 1523 is repeated until the count number of the counter i or j exceeds the maximum value at 20. During this time, when the drawing operation by the 16 laser beams reaches the start position of the complete blank area, the feed speed of the drawing table 10 is accelerated to twice the feed speed during the drawing operation.

When the count value of the counter i or j exceeds the maximum value in step 1520, the process proceeds from step 1520 to step 1524, where it is determined whether or not the drawing operation has been completed. When the completion of the drawing operation is confirmed,
Proceeding to step 1525, in which execution of the raster conversion interrupt routine is commanded to stop, and then control returns to step 1312 of the operation routine of FIG.

Referring to FIG. 17, there is shown a flowchart of the acceleration / deceleration setting routine. This acceleration / deceleration setting routine is executed in step 1503 of the drawing routine shown in FIGS. 15 and 16 as described above.

At step 1701, counters i and j
Is reset, and then the process proceeds to step 1702, where the start position data X _{(i = 0) of the} complete blank area is removed by the numerical value 16. That is, as shown in FIG. 18, the drawing lines in the main scanning direction arranged in the sub-scanning direction are divided in units of 16 lines. Next, in step 1703, it is determined whether or not there is a remainder as a result of the division. When there is no remainder, that is, as is apparent from FIG.
When the start position data X _{(i = 0) of the} complete blank area matches the last main scanning direction drawing line among the last 16 main scanning direction drawing lines indicated by the quotient value of the above division Proceeds from step 1703 to step 1704, where the following calculation is performed to obtain acceleration start position data SX _{(i = 0)} . SX _{(i = 0)} ← d * quotient Here, “d” is the width in the sub-scanning direction of the drawing record obtained by the drawing scan with 16 laser beams, and the size in pixel unit, that is, the dot diameter is 5 μm. Then d is
0.08 mm. That is, acceleration start position data SX _{(i = 0)}
Is the distance from the drawing start position.

On the other hand, if there is a remainder in the multiplication in step 1703, steps 1703 to 170
Then, the following calculation is performed to obtain acceleration start position data SX _{(i = 0)} . SX _{(i = 0)} ← d * (quotient + 1) Of course, also in this case, the acceleration start position data SX _{(i = 0)} is the distance from the drawing start position, and the start position data X _{(i = 0) of the} complete blank area Includes main scanning direction drawing line that matches
It corresponds to the position of the last main scanning direction drawing line among the 16 main scanning direction drawing lines.

[0102] In summary, the acceleration start position data SX _i 16
The 16 during that contains the main scanning direction drawing lines matching the start position data X _i of a complete blank area in the main scanning direction drawing line 16 when the sub-scanning direction of the drawing scanning according to the laser beam Is defined as the distance from the drawing start position in the sub-scanning direction of the last drawing line in the main scanning direction among the drawing lines in the main scanning direction.

Step 1704 or step 170
When the calculation for obtaining the acceleration start position data SX _{(i = 0)} is completed in step 5, the process proceeds to step 1706, where the count number of the counter i is incremented by "1".

In step 1707, the end position data X _{(j = 0) of} the complete blank area is divided by the numerical value 16.
That is, as shown in FIG. 19, the drawing lines in the main scanning direction arranged in the sub-scanning direction are divided in units of 16 lines. Next, at step 1708, it is determined whether or not there is a remainder as a result of the division. If there is not much,
That is, as is apparent from FIG. 19, the end position data X _{(j = 0)} of the complete blank area is the last of the last 16 main scanning direction drawing lines indicated by the value of the quotient of the division. If it matches the drawing line in the main scanning direction, step 1
The process proceeds from step 708 to step 1709, where the following calculation is performed to obtain deceleration end position data SX _{(j = 0)} . SX _{(j = 0)} ← d * (quotient-1) where “d” is the width in the sub-scanning direction of the drawing record obtained by the drawing scan using 16 laser beams, as in the above case, and is 0.08 mm. Is a constant with a numerical value of. That is,
The deceleration end position data SX _{(j = 0)} is also the distance from the drawing start position.

On the other hand, if there is a remainder in the multiplication in step 1707, steps 1708 to 171
Then, the following calculation is performed to obtain deceleration end position data SX _{(j = 0)} . SX _{(j = 0)} ← d * quotient Of course, in this case as well, the acceleration start position data SX _{(j = 0)} is the distance from the drawing start position.

[0105] In short, the deceleration end position data SX _j 16
At the time of drawing scanning in the sub-scanning direction by the laser beam, 16 drawing lines in the main scanning direction including the drawing line in the main scanning direction corresponding to the end data _Xj of the complete blank area among the 16 drawing lines in the main scanning direction. The drawing position of the last main scanning direction drawing line among the 16 preceding main scanning direction drawing lines is defined as the distance from the drawing start position in the sub-scanning direction.

Step 1709 or step 171
When the calculation for obtaining the deceleration end position data SX _{(j = 0)} is completed at ₀ , the process proceeds to step 1711, where the count number of the counter j is incremented by "1".

Next, at step 1712, it is determined whether or not the count number of the counter i or j has exceeded its maximum value. If the count number of the counter i or j is equal to or less than the maximum value, the process returns to step 1702, and the acceleration start position data SX _{(i = 0)} and the deceleration end position data SX ₍ until the counter number exceeds the maximum value _{). j = 0)} are created sequentially. When the number of counters i or j exceeds the maximum value, the process returns to step 1504 of the drawing routine shown in FIGS.

Referring to FIG. 20, there is shown a flowchart of the raster conversion interrupt routine, which is executed in step 1506 of the drawing routine of FIGS. 15 and 16 as described above. At appropriate time intervals. As described above, before this raster conversion interrupt routine is executed, step 150 of the drawing routine shown in FIGS.
At 4 and 1505, counter n is reset,
The flags F1 and F2 are set to "1".

In step 2001, it is determined whether the raster conversion flag F _{(n = 0)} is "1" or "0". If the raster conversion flag F _{(n = 0)} = 1, that is, if the partition P _{(n = 0)} includes at least a part of the pattern to be drawn, the process proceeds from step 2001 to step 2002, where the flag F1 Is "1" or "0". The flag F1 is a flag for instructing whether to permit or prohibit the writing of the raster data to the first bitmap memory 86B. If F1 = 1, the first bitmap memory 86B
The writing of the raster data to is permitted, and if F1 = 0, the writing is prohibited.

In the initial state of the present stage, since the writing of the raster data to the first bitmap memory 86B is possible (ie, F1 = 1), the raster conversion flag F _{(n = 0) )} = 1 (step 2001),
The process proceeds from step 2002 to step 2003, in which vector data for the partition P _{(n = 0)} is sequentially read from the buffer memory 80, and the read vector data is converted into raster data by a raster conversion circuit 86A, and the first bit is read. The data is written to the map memory 86B.
When writing the raster data to the first bitmap memory 86B, it goes without saying that the switch circuit 86D is connected to the first bitmap memory 86B.

When the writing of the raster data to the first bitmap memory 86B is started in step 2003,
In step 2004, the flag F1 is rewritten from "1" to "0". Then, step 2005
Then, the count number of the counter n is counted up by "1".

On the other hand, if the raster conversion flag F _{(n = 0)} = 0 in step 2001, that is, if the partition P _{(n = 0)} is included in the complete blank area, step 2
From 001, the process proceeds to step 2006, where the reading of the vector data for the partition P _{(n = 0)} from the buffer memory 80 is stopped. Next, the process proceeds from step 2006 to step 2005, where the count of the counter n is incremented by "1".

In step 2005, when the count of the counter n is counted up by "1", the process proceeds to step 2007, where the first bitmap memory 86B
It is determined whether or not the reading of the raster data from has been completed, that is, whether or not the drawing operation based on the raster data stored in the first bitmap memory 86B has been completed. At this stage, the reading of the raster data from the first bitmap memory 86B has not been completed.
Skip to step 2009. On the other hand, if the drawing operation based on the raster data stored in the first bitmap memory 86B is completed while the execution of this raster conversion interrupt routine is repeated many times, the process proceeds to step 20.
From 07, the process proceeds to step 2008, in which the flag F1 is rewritten from "0" to "1", whereby the first bitmap memory 86B becomes ready to write raster data.

In step 2009, it is determined whether the raster conversion flag F _{(n = 1)} is "1" or "0". If the raster conversion flag F _{(n = 1)} = 1, that is, if at least a part of the pattern to be drawn is included in the partition P _{(n = 1)} , the process proceeds from step 2009 to step 2010, where the flag F2 Is "1" or "0". The flag F2 is a flag for instructing whether to allow or prohibit the writing of the raster data to the second bitmap memory 86C. If F2 = 1, the second bitmap memory 86C
The writing of the raster data to is permitted, and if F2 = 0, the writing is prohibited.

In the initial state at the present stage, the raster data can be written into the second bitmap memory 86C (ie, F2 = 1), so that the raster conversion flag F _{(n = 1) )} = 1 (step 2009),
The process proceeds from step 2010 to step 2011, in which vector data for the partition P _{(n = 1)} is sequentially read from the buffer memory 80, and the read vector data is converted into raster data by the raster conversion circuit 86A, and the second bit The data is written to the map memory 86C.
When writing the raster data to the second bitmap memory 86C, it goes without saying that the switch circuit 86D is connected to the second bitmap memory 86C.

When the writing of raster data to the second bitmap memory 86C is started in step 2011,
In step 2012, the flag F2 is rewritten from "1" to "0". Next, step 2013
Then, the count number of the counter n is counted up by "1".

On the other hand, when the raster conversion flag F _{(n = 1)} = 0 in step 2009, that is, when the partition P _{(n = 1)} is included in the complete blank area, step 2
From step 009, the process proceeds to step 2014, where reading of vector data for the partition P _{(n = 1)} from the buffer memory 80 is stopped. Next, the process proceeds from step 2014 to step 2013, where the count of the counter n is counted up by "1".

In step 2013, when the count number of the counter n is counted up by "1", the process proceeds to step 2015, where the second bitmap memory 86C
It is determined whether or not the raster data has been completely read from the second bitmap memory 86C, ie, whether or not the drawing operation based on the raster data stored in the second bitmap memory 86C has been completed. At this stage, since the reading of the raster data from the second bitmap memory 86C has not been completed, the raster conversion interrupt routine ends once. On the other hand, if the drawing operation based on the raster data stored in the second bitmap memory 86C is completed while the execution of the raster conversion interrupt routine is repeated many times, the process proceeds from step 2015 to step 2016, where the flag F " Is rewritten from “0” to “1”, thereby enabling a state in which raster data can be written to the second bitmap memory 86C.

[0119]

As is apparent from the above description, according to one aspect of the present invention, first, for a drawing pattern extending over a plurality of bands, the entire width of the drawing pattern in the main scanning direction is detected in advance, and the entire width is determined. By setting the band corresponding to the above, it is possible to determine whether the reduction of the set band number can be achieved, and to shorten the entire drawing time.

According to another aspect of the present invention, the reading of the vector data from the buffer memory is divided for each partition, and the reading of the vector data of the partition included in the complete blank area is stopped. Further, the vector data read by being partitioned by the partitions is converted into raster data by a raster conversion circuit, and then written alternately to a first bitmap memory and a second bitmap memory to be subjected to a drawing operation. . On the other hand, while the drawing by the laser beam reaches the complete blank area, the moving speed of the drawing object, that is, the drawing table in the sub-scanning direction is increased. In short, another aspect of the present invention is to significantly reduce the drawing time by a plurality of bands by efficiently converting vector data to raster data and improving the efficiency of the drawing operation. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a laser drawing apparatus according to the present invention.

FIG. 2 is a block diagram of the laser drawing apparatus shown in FIG.

FIG. 3 is a detailed block diagram of a drawing data processing circuit shown in FIG. 2;

FIG. 4 is a schematic diagram illustrating an example of a drawing pattern that straddles three bands of a first band, a second band, and a third band and has a width in the main scanning direction of two or more bands.

FIG. 5 is a schematic diagram illustrating an example of a drawing pattern that straddles three bands but has a width in the main scanning direction that is equal to or less than two bands.

FIG. 6 is a schematic diagram showing an example of a drawing pattern included in two bands but having a width in the main scanning direction of one band or less.

FIG. 7 is a schematic diagram illustrating detection of a completely blank area along a main scanning direction of a partial drawing pattern of a first band illustrated in FIG. 4;

FIG. 8 is a schematic diagram illustrating detection of a completely blank area along a main scanning direction of a partial drawing pattern of a second band illustrated in FIG. 4;

9 is a schematic diagram illustrating detection of a completely blank area along a main scanning direction of a partial drawing pattern of a third band illustrated in FIG. 4;

10 is a partially enlarged view of a partial drawing pattern of a first band shown in FIG. 4, and is a schematic diagram showing a relationship between a completely blank area and partitions.

FIG. 11 is a part of a flowchart showing a vector data processing routine executed by an engineering workstation (EWS) of the laser drawing apparatus.

FIG. 12 is the remaining part of the flowchart showing the vector data processing routine executed by the engineering workstation (EWS) of the laser drawing apparatus.

FIG. 13 is a flowchart showing a drawing operation routine executed by the laser drawing apparatus itself.

FIG. 14 is a flowchart illustrating a raster conversion flag setting routine included in the drawing operation routine of FIG. 13;

FIG. 15 is a part of a flowchart showing a drawing routine included in the drawing operation routine of FIG. 13;

16 is the remaining part of the flowchart showing the drawing routine included in the drawing operation routine of FIG.

FIG. 17 is a flowchart showing an acceleration / deceleration setting routine included in the drawing routines of FIGS. 15 and 16;

FIG. 18 is a schematic diagram for explaining calculation of acceleration start data in an acceleration / deceleration setting routine of FIG.

19 is a schematic diagram for explaining calculation of deceleration end position data in an acceleration / deceleration setting routine of FIG.

FIG. 20 is a flowchart showing a raster conversion interruption routine executed in parallel with the drawing routines of FIGS. 15 and 16;

[Explanation of symbols]

 Reference Signs List 10 drawing table 12 argon laser generator 40/46 electronic shutter 58 polygon mirror 66 engineering workstation (EWS) 68 host controller 70 keyboard 72 hard disk drive 74 CRT display 76 system controller 78 LAN interface circuit 80 buffer memory 82 main scanning control circuit 84 Synchronization circuit 86 Drawing data processing circuit 86A Raster conversion circuit 86B First bitmap memory 86C Second bitmap memory 86D First switch circuit 86E Second switch circuit 88 Y scale sensor 90 Signal processing circuit 92 XY drive mechanism Control circuit 94 Sub-scanning control circuit 96 X-axis servo motor 98 X-axis drive circuit 100 X-scale sensor 102 Signal processing circuit 104 Y-axis servo motor Motor 106 Y-axis drive circuit

Claims (3)

[Claims] An object to be drawn is moved in a sub-scanning direction while deflecting a laser beam in the main scanning direction with respect to the object to be drawn, and the laser beam is modulated based on raster data to form a desired drawing pattern. What is claimed is: 1. A laser writing apparatus configured to record on an object to be drawn, wherein the writing pattern is obtained by synthesizing a partial writing pattern based on at least two or more N bands. Wherein the total width of the desired drawing pattern in the main scanning direction is detected in advance, and when the total width is shorter than the length of the total band of (N-1) or less, the desired width is determined based on the number of the total bands. A laser writing apparatus, wherein a writing start position of each of the partial writing patterns is shifted so as to obtain a writing pattern. 2. The object to be drawn is moved in the sub-scanning direction while deflecting the laser beam in the main scanning direction with respect to the object to be drawn, and the laser beam is modulated based on raster data to form a desired drawing pattern. In the laser writing apparatus adapted to record on the object to be drawn, a complete blank area along the main scanning direction in the drawing pattern is detected in advance, and the drawing is performed while the drawing by the laser beam reaches the complete blank area. A laser writing apparatus characterized in that a moving speed of a drawing body in a sub-scanning direction is increased. 3. The object to be drawn is moved in the sub-scanning direction while deflecting the laser beam in the main scanning direction with respect to the object to be drawn, and the laser beam is modulated based on raster data to form a desired drawing pattern. What is claimed is: 1. A laser writing apparatus configured to record on an object to be drawn, wherein the writing pattern is obtained by synthesizing a partial writing pattern based on at least two or more N bands. Wherein the total width of the desired drawing pattern in the main scanning direction is detected in advance, and when the total width is shorter than the length of the total band of (N-1) or less, the desired width is determined based on the number of the total bands. The drawing start position of each of the partial drawing patterns is shifted so that a drawing pattern is obtained. Complete blank area along the 査 direction are previously detected, while the drawing by the laser beam spans the full blank area,
A moving speed of the object to be drawn in the sub-scanning direction is increased.