JP5270891B2 - Image recording method and image recording system - Google Patents

Description

  The present invention relates to an image recording method and an image recording system for directly drawing a predetermined drawing pattern represented by digital data on a plurality of drawing objects.

  Conventionally, an image recording system for directly drawing a predetermined drawing pattern represented by digital data on a drawing object has been developed. As an image recording system, for example, an object to be drawn such as a printed wiring board or a glass panel for a flat panel display on which a photosensitive material is applied or pasted is irradiated with a light beam modulated according to a drawing pattern. Therefore, a digital exposure system that performs exposure recording without mask is known.

  The digital exposure system is built into a large manufacturing system that integrates a series of processes from drawing pattern design and drawing object production to inspection of exposed drawing objects, packing, and shipping. It plays the role of pattern exposure. The drawing pattern is designed by, for example, CAD (Computer Aided Design), and vector data obtained by editing the drawing pattern designed by CAD by CAM (Computer Aided Manufacturing) is given to the digital exposure system. In a digital exposure system, given vector data is rasterized by a raster image processor (RIP), and raster data generated thereby (whether exposure recording is performed for each pixel, “0” or “1”). Exposure recording is performed by driving and controlling a spatial light modulation element such as a DMD (Digital Micromirror Device (registered trademark)).

  In the digital exposure system, an important issue is how to accurately expose the drawing pattern at the normal position of the drawing object due to the nature of the product to be handled. This is because if the exposure position of the drawing pattern is shifted, not only the performance of the product is remarkably deteriorated, but also the product may be defective and the yield may be deteriorated.

  However, the object to be drawn is shifted from the reference size due to the manufacturing conditions and the surrounding environment, such as thermal expansion when the press process is performed in the process before reaching the digital exposure system (two-dimensional in the vertical and horizontal directions). Expansion and contraction) occurs. For this reason, it is necessary to measure the amount of deviation from the reference size of the drawing object, and to correct the digital data that is the basis of the drawing pattern according to the measurement result. For example, when the actual size of the drawing object is 1.0001 and 0.9999 times when the reference size of the drawing object is standardized to be 1 time in the vertical and horizontal directions, the digital data is also 1.0001 and 0 in the vertical and horizontal directions. It is necessary to perform a magnification process of 9999 times.

  Based on the above background, the phase shift amount of the clock pulse that controls the light beam is substantially matched with the difference between the reference size of the drawing object and the actually measured size, and the digital data is less than one pixel unit. There has been proposed a laser drawing apparatus that can perform zooming processing (scaling correction processing) (see Patent Document 1). Further, in the same laser drawing apparatus, in order to facilitate the process (inspection and the like) after the drawing pattern is recorded, identification data such as a lot number and expansion / contraction rate data (scaling correction information data) are obtained for each drawing object. There is disclosed a technique of holding in relation to (see Patent Document 2).

On the other hand, as a cause of the drawing pattern being shifted from the reference position, in addition to the above-described deviation of the drawing object, there is a deviation in optical characteristics caused by an assembly error of an exposure unit including a DMD or a manufacturing error of parts. In Patent Document 3, in order to eliminate such a shift in the exposure position, a shift in the optical characteristics of the exposure unit is known in advance, and based on this, the raster data is subjected to an electronic scaling process.
JP 09-323180 A Japanese Patent Laid-Open No. 10-282684 JP 2006-251207 A

  In the techniques described in Patent Documents 1 and 2, since it is necessary to perform different scaling correction processes one by one in accordance with the deviation from the reference size of each individual drawing object, each scaling correction process takes time. It takes. Therefore, it takes a long time to expose each object to be drawn, resulting in a decrease in product productivity. Even if the technique described in Patent Document 3 is applied, this problem cannot be solved because the electronic scaling process with different scaling ratios is not changed for each drawing object.

  In addition, in Patent Documents 1 and 2, many components such as a multiplexer and a delay line must be added to shift the phase of the clock pulse. In addition, Patent Document 3 does not describe in detail the specific configuration for performing the electronic scaling process. However, the electronic scaling process is usually performed using raster data such as a latch circuit or a FiFo memory. Is performed by interpolating or thinning out pixels corresponding to the scaling factor (see, for example, Japanese Patent Laid-Open No. 06-086056), the larger the scaling factor, the larger the number of necessary hardware, and the scaling processing. The image quality of the later raster data also deteriorates.

  The present invention has been made in view of the above problems, and provides an image recording method and an image recording system capable of minimizing an increase in image recording time due to scaling processing and image quality degradation of the image. With the goal.

  In order to achieve the above object, an invention according to claim 1 is directed to an image recording system for directly drawing a predetermined drawing pattern represented by digital data on a plurality of drawing objects. A first scaling process means for performing a first electronic scaling process on the digital data at a common first scaling ratio, and a second scaling ratio that is different for each of the plurality of drawing objects, Second scaling processing means for applying a second electronic scaling process to the digital data, and the first and second scaling processing means perform the first and second electronic scaling processes, A shift in the recording position of the drawing pattern due to a shift from the reference size of the drawing object is corrected.

  The first scaling processing means performs the first electronic scaling processing as an external setup operation before drawing the drawing pattern on the drawing object, and the second scaling processing means It is preferable that the second electronic scaling process is performed as an internal setup operation while the drawing pattern is being drawn on the drawing body. That is, the first electronic scaling process is performed only once for one digital data. On the other hand, the second electronic scaling process is performed every time recording is performed on the drawing object.

  The first scaling factor is preferably set based on an average value of deviation amounts from a reference size of the drawing object or an intermediate value between maximum and minimum values.

  The average value or the intermediate value is obtained empirically from the past manufacturing results of the drawing object. Alternatively, a first deviation amount measuring unit that actually measures a deviation amount from a reference size of the drawing object is provided, and the average value or the intermediate value is obtained from an actual measurement value of the deviation amount by the first deviation amount measuring unit. It is required.

  A second shift amount measuring unit that measures a shift amount from a reference size of the drawing object, wherein the second scaling factor is the first scaling factor and the shift amount by the second shift amount measuring unit; It is preferable to set based on the actual measurement value.

  It is preferable that the first scaling unit is realized by software, and the second scaling unit is realized by hardware.

  A raster image processor that rasterizes vector data of the drawing pattern and generates raster data as the digital data, wherein the first scaling processing means adjusts the RIP resolution at the time of the rasterization, so that the raster The data is preferably subjected to the first electronic scaling process.

  According to a ninth aspect of the present invention, there is provided an image recording method for directly drawing a predetermined drawing pattern represented by digital data on a plurality of drawing objects at a first scaling factor common to the plurality of drawing objects. A first scaling process for applying a first electronic scaling process to the digital data, and a second scaling factor that is different for each of the plurality of drawing objects, A second scaling process step for performing an electronic scaling process, and in the first and second scaling process steps, the first and second electronic scaling processes reduce the drawing object from a reference size. The recording position shift of the drawing pattern due to the shift is corrected.

  According to the image recording method and the image recording system of the present invention, a plurality of objects to be drawn are subjected to an electronic scaling process for correcting a deviation of a drawing pattern recording position caused by a deviation from a reference size of the object to be drawn. This is done in two stages: a first electronic scaling process performed at a common scaling ratio and a second electronic scaling process performed at a different scaling ratio for each of a plurality of drawing objects. Most of the scaling process is performed once by the first electronic scaling process, and the remaining part that cannot be adjusted by the first electronic scaling process is performed by the second electronic scaling process for each drawing object. The process that can be finely adjusted and substantially affects the image recording time is only the second electronic scaling process having a smaller scaling ratio than the first electronic scaling process. Therefore, an increase in image recording time due to the scaling process can be minimized. Further, if the first electronic scaling process is performed with a configuration with little image quality deterioration, the image quality deterioration of the image due to the scaling process can be minimized.

  In FIG. 1, the digital exposure system 2 includes a digital exposure machine 10, a light source unit 11, an image processing unit 12, and a control device 13. The digital exposure system 2 uses the image processing unit 12 to rasterize vector data obtained by editing a predetermined drawing pattern (for example, a printed wiring pattern) designed by CAD (Computer Aided Design) by CAM (Computer Aided Manufacturing). Based on the generated raster data (existence of exposure recording for each pixel expressed by binary of “0” or “1”), the object 14 is exposed using the digital exposure machine 10 and the light source unit 11. By doing so, a desired image is formed on the drawing object 14 without a mask.

  The drawing object 14 is made of, for example, a printed wiring board having a photosensitive material applied or stuck on the surface thereof or a glass substrate for flat panel display. An alignment mark 15 indicating the reference of the exposure position is provided on the upper surface of the drawing object 14. For example, the alignment marks 15 are formed by unevenness of a thin film, and four alignment marks are arranged at four corners of the drawing target 14, respectively.

  The digital exposure machine 10 has a flat base 16. The base 16 is supported by the four legs 17 and is arranged in parallel to the horizontal plane. On the upper surface of the base 16, two guide rails 18 parallel to the Y direction (a direction parallel to the longitudinal direction of the base 16) are provided side by side. A moving stage 19 that sucks and holds the drawing target 14 is attached to the guide rail 18 so as to be slidable in the Y direction. The moving stage 19 is reciprocated in the Y direction by a stage driving unit 74 (see FIG. 4) including a driving source such as a linear motor. Although not shown, the moving stage 19 is provided with a mechanism for adjusting the position in the Z direction (direction orthogonal to the horizontal plane).

  An exposure unit 20 is disposed at the center of the base 16 in the Y direction. The exposure unit 20 is fixed to a gate-shaped first gate 21 erected so as to straddle the guide rail 18. The exposure unit 20 is provided with a total of sixteen cylindrical exposure heads 22 arranged in two rows of eight in the X direction (the direction perpendicular to the Y direction on the horizontal plane).

  An optical fiber 23 drawn from the light source unit 11 and a signal cable 24 drawn from the image processing unit 12 are connected to the exposure head 22. The exposure head 22 is input from the light source unit 11 via the optical fiber 23 based on the frame data (the raster data divided for each exposure head 22) input from the image processing unit 12 via the signal cable 24. A laser beam (hereinafter abbreviated as LB) is modulated. Then, the modulated LB is irradiated to the drawing object 14 that passes directly under the movement of the moving stage 19 in the Y direction to perform exposure.

  The exposure heads 22 are arranged without a gap between the first row and the second row. The exposure heads 22 are arranged so as to be shifted by 1/2 pitch (radius) in the X direction between the first row and the second row. Thereby, the part which cannot be exposed with the exposure head 22 of the 1st row | line | column is exposed with the exposure head 22 of the 2nd row | line, and the to-be-drawn body 14 can be exposed in the X direction without gap. Note that the number of exposure heads 22 and the way in which they are arranged can be appropriately changed according to the specifications of the drawing target 14.

  In FIG. 2, the exposure head 22 includes an incident optical system 30, a light modulator 31, a first emission optical system 32, a microlens array 33, an aperture array 34, and a second emission optical system 35. The incident optical system 30 is disposed so as to face the exit end of the optical fiber 23. The incident optical system 30 includes a condenser lens 36, an optical integrator 37, an imaging lens 38, and a mirror 39.

  The condensing lens 36 condenses the LB (indicated by an arrow) emitted from the optical fiber 23 toward the optical integrator 37. The optical integrator 37 is disposed on the optical path of the LB that has passed through the condenser lens 36, and is made of, for example, a rectangular column-shaped translucent rod in which an incident end face and an exit end face are coated with an antireflection film. The optical integrator 37 converts the LB that travels while totally reflecting the inside thereof into substantially parallel light with uniform intensity in the beam cross section. The LB converted into substantially parallel light by the optical integrator 37 is guided to the mirror 39 by the imaging lens 38 and is incident on the light modulator 31 by the mirror 39.

  The light modulation unit 31 includes a digital micromirror device (hereinafter abbreviated as DMD) 40 that is a spatial light modulation element, a DMD driver 41 that controls the operation of the DMD 40, and an LB incident through a mirror 39. And a total reflection prism 42 that reflects toward the DMD 40.

  In FIG. 3, the DMD 40 is configured such that a micromirror 61 is tiltably supported by a column on each SRAM cell constituting the SRAM cell array 60. For example, the micromirrors 61 are arranged in a 600 × 800 two-dimensional square lattice pattern.

  Frame data is written into each SRAM cell via the DMD driver 41. The SRAM cell is configured by a flip-flop circuit, and the charge state is switched depending on the frame data (“0” or “1”) to be written. The inclination angle of the micromirror 61 is changed by the electrostatic force according to the charge state of the SRAM cell, and the reflection direction of the LB also changes accordingly. For example, the micromirror 61 of the SRAM cell in which the frame data “0” is written is tilted so that LB enters the first emission optical system 32. On the other hand, when “1” is written, LB is inclined so as to enter a light absorber (not shown). LB incident on the light absorber is absorbed by the light absorber and does not contribute to exposure. Note that the DMD 40 has a short side slightly inclined with respect to the Y direction (for example, 0.1 ° to 0.00 mm) in order to increase the exposure resolution by narrowing the interval in the X direction of the scanning trajectory by each exposure head 22. 5 °).

  Returning to FIG. 2, the first emission optical system 32 includes lenses 43 and 44, and LB from the light modulation unit 31 is enlarged to a predetermined magnification and is incident on the microlens array 33. The microlens array 33 is made of a light-transmitting material, for example, quartz glass, and a plurality of plano-convex lens-like microlenses 45 are integrally formed. The microlenses 45 have a one-to-one correspondence with the micromirrors 61 and are positioned on the optical axis of the incident LB. Due to the action of the micro lens 45, the incident LB is sharpened and incident on the aperture array 34.

  The aperture array 34 has a plurality of apertures 46 corresponding to the micromirrors 61 and arranged in a two-dimensional square lattice. The aperture array 34 is formed, for example, by depositing a light shielding film such as chromium on a quartz glass plate, and forming holes serving as the apertures 46 in the light shielding film. The LB incident from the microlens array 33 is focused at the position of the aperture 46 and guided to the second emission optical system 35. The aperture array 34 prevents unnecessary light from passing due to chattering of the micromirror 61 and further increases the sharpness of the LB.

  The second emission optical system 35 includes lenses 47 and 48 and a prism pair 49. The lenses 47 and 48 enlarge the LB from the aperture array 34 to a predetermined magnification, or enter the prism pair 49 with the same magnification. The prism pair 49 includes, for example, a pair of wedge-shaped prisms 49a and 49b obtained by cutting a transparent parallel plate along a plane inclined obliquely with respect to the parallel plane of the parallel plate. The wedge-shaped prism 49a is provided so as to be movable in a direction along the inclined surface with respect to the wedge-shaped prism 49b by a focus control unit (not shown) including a driving source such as a stepping motor, and the wedge-shaped prism 49a moves. Thus, the focus of the LB is adjusted so that the LB is focused on the exposure surface 14a.

  Returning to FIG. 1, the light source unit 11 is provided with a plurality of GaN-based semiconductor lasers that emit LB having an oscillation wavelength in the range of 350 nm to 450 nm (for example, 405 nm). The GaN-based semiconductor laser has a maximum output of about 100 mW in the multimode and about 50 mW in the single mode. The LB emitted from each of the GaN-based semiconductor lasers is guided to the incident end of the optical fiber 23 as it is or after being multiplexed several times. Note that other types of semiconductor lasers or light emitting diodes (LEDs) may be used instead of the GaN-based semiconductor lasers.

  A gate-shaped second gate 25 is further erected on the base 16 so as to straddle the guide rail 18. A pair of length measuring devices 26 is attached to one end of the base 16 in the Y direction. The second gate 25 is provided with three cameras 27 that photograph from the upper side in the Z direction the subject to be drawn 14 that passes immediately below as the moving stage 19 moves in the Y direction. The camera 27 incorporates a solid-state imaging device such as a CCD image sensor, and outputs an imaging signal obtained by the solid-state imaging device to the position detection unit 75 (see FIG. 4).

  The length measuring device 26 employs, for example, a laser interference type that measures the position of the moving stage 19 in the Y direction by irradiating the side end surface of the moving stage 19 with laser light and receiving the reflected light. . The length measuring device 26 is connected to the control device 13 (see FIG. 4), and outputs the length measurement result to the control device 13. In addition, as a length measuring device, you may use what comprises an ultrasonic transmitter / receiver and a stereo camera.

  In FIG. 4, the control device 13 comprehensively controls the overall operation of the digital exposure system 2. The control device 13 stores in advance a program and data for performing the above-described control in a storage unit (not shown) such as an HDD or a ROM. The control device 13 reads out necessary programs and data from the storage unit, develops them in a working memory such as a RAM, and sequentially processes the read programs.

  In addition to the light source unit 11 described above, the control device 13 includes a memory 70 of the image processing unit 12, a raster image processor (hereinafter abbreviated as “RIP”) 71, an adjustment scaling processing unit (second scaling processing). 72), the frame data generation unit 73, the DMD driver 41 of the digital exposure apparatus 10, the stage drive unit 74, the position detection unit 75, and the length measuring device 26 are connected.

  The memory 70 temporarily stores vector data transmitted from an external device such as a CAM. The RIP 71 reads vector data from the memory 70 and rasterizes the vector data to generate raster data. The RIP 71 outputs the generated raster data to the adjustment scaling unit 72.

  The RIP 71 is provided with a reference scaling processing unit (corresponding to first scaling processing means) 76. The reference scaling processing unit 76 adjusts the RIP resolution at the time of rasterization using a known pixel interpolation technique such as the nearest neighbor method (interpolates (enlarges) pixels constituting raster data according to the reference scaling factor). Or thinning out (reducing)), the raster data is subjected to an electronic scaling process. When the new vector data is read from the memory 70, the reference scaling processing unit 76 performs the electronic scaling process only once as an external setup (offline) work before the drawing object 14 is exposed. I do.

  Here, the reference scaling factor corresponds to the first scaling factor, and as conceptually shown in FIG. 5, the amount of deviation from the reference size of the drawing object 14 (standard size is normalized to 1 × vertical and horizontal). (For example, 0.9995 in height and width, 1.0008 times).

  The deviation of the drawing object 14 from the reference size is caused by thermal expansion or the like when the drawing object 14 is subjected to press processing in the process before reaching the digital exposure system 2, and the degree thereof is about 0. 0. 1%. Further, the average value of the deviation amount, that is, the reference scaling factor, can be estimated from a past production result to be an approximately accurate value empirically. In the present embodiment, processing is performed using a reference scaling factor obtained empirically. Specifically, empirically obtained reference magnification data is stored in the storage unit of the control device 13 in advance, and this data is read out to the reference magnification processing unit 76, and based on the read data. Double the process.

  The reference scaling factor is obtained by measuring the deviation amounts of all the drawing objects 14 to be exposed as shown in the calculation formula shown in the lower part of FIG. 5 and adding up and dividing the result by the number (n). You may use what was calculated | required and may measure the amount of shift | offset | differences selected several randomly among the to-be-drawn objects 14 used as exposure object, and may use the average value. Alternatively, the maximum and minimum intermediate values may be used instead of the average value of the deviation amounts. In this case, for example, if the maximum is 1.0008 and the minimum is 0.9994, the intermediate value is (1.0008 + 0.9994) /2=1.0001.

  The RIP 71 is a so-called software RIP realized by operating a digital signal processing microprocessor such as a DSP (Digital Signal Processor) in accordance with an RIP program stored in the storage unit of the control device 13. Of course, the function of the reference scaling processing unit 76 in the RIP 71 is also realized by software.

  The adjustment scaling unit 72 performs electronic scaling processing according to the adjustment scaling factor on the raster data from the RIP 71 using the same method as the reference scaling processing unit 76. The adjustment scaling processing unit 72 performs the electronic scaling processing as an internal setup (online) operation during exposure of the drawing target 14 every time the drawing target 14 to be exposed is changed. Do.

  The adjustment scaling factor corresponds to the second scaling factor, and is obtained by dividing the size of the raster data scaled by the reference scaling processing unit 76 by the size of the drawing object 14 actually measured by the position detection unit 75. . For example, when the reference scaling ratio is 1.0001 and 0.9991 times in the vertical and horizontal directions, and the actual measurement size of the drawing object 14 by the position detection unit 75 is 1.0002 and 0.9992 times in the vertical and horizontal directions, the adjustment scaling ratio is (1.0002 / 1.0001≈1.00009999), (0.9999 / 0.9991≈1.0001001) times. That is, the adjustment scaling factor absorbs the deviations of the individual sizes of the drawing object 14 that cannot be adjusted by the reference scaling process, and is fine so that the size of all the drawing objects 14 matches the size of the raster data. Of course, it is a value that is extremely small compared to the reference scaling factor.

  The adjustment scaling processing unit 72 is not realized by software like the RIP 71 and the reference scaling processing unit 76, but is an adjustment scaling processing such as ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). It is built with hardware that is dedicated to processing functions.

  The frame data generation unit 73 obtains raster data from the adjustment scaling processing unit 72 for each exposure head 22 based on the exposure position of each exposure head 22 on the drawing target 14 determined by the arrangement of the micromirror 61 and the exposure head 22. Frame data divided into two. In addition, the frame data generation unit 73 performs exposure at the same position as when no shift occurs according to the shift amount of the drawing object 14 with respect to the reference position on the moving stage 19 detected by the position detection unit 75. As described above, the frame data is corrected. The frame data generation unit 73 outputs the generated frame data to the DMD driver 41 of the corresponding exposure head 22. As described above, the DMD driver 41 writes the frame data from the frame data generation unit 73 into the SRAM cell. The correction of the frame data described above is to correct a deviation from the reference placement position of the drawing object 14 on the moving stage 19. The reference and adjustment for correcting the deviation from the reference size of the drawing object 14 itself. This is a process different from the scaling process.

  The position detection unit 75 converts the image pickup signal from the camera 27 into digital image data by known signal processing. Based on the converted image data, the position of the camera 27 in the X direction, and its shooting timing (both the position and the shooting timing are known), the position detection unit 75 positions the alignment mark 15 of the drawing object 14 on the moving stage 19. Is detected. The position detection unit 75 outputs the position detection result to the control device 13.

  The control device 13 receives the detection result from the position detection unit 75, and the X direction, the Y direction, and the θ direction of the drawing target 14 with respect to the reference position on the moving stage 19 (the rotation direction about the Z direction, 1) is calculated. In addition, the control device 13 calculates a deviation amount from the reference size of the drawing target 14. Specifically, based on the position coordinates in the X and Y directions of the alignment mark 15 measured by the position detection unit 75 and the reference position coordinates stored in advance in the storage unit, the actual measurement value and the reference value of the vertical and horizontal sizes of the drawing object 14 are obtained. Values and take these ratios. The control device 13 calculates the adjustment scaling ratio and the correction amount of the frame data from these calculated deviation amounts, and outputs the information to the adjustment scaling processing section 72 and the frame data generation section 73, respectively.

  Next, the operation procedure of the digital exposure system 2 configured as described above will be described with reference to the flowchart of FIG. First, in S10, prior to exposure recording, vector data is transmitted from an external device such as a CAM to the memory 70, and the vector data is stored in the memory 70.

  The vector data stored in the memory 70 is read out to the RIP 71. In S11, the RIP 71 rasterizes the vector data to generate raster data. At this time, the reference magnification processing unit 76 adjusts the RIP resolution based on the reference magnification data read from the storage unit of the control device 13, and the raster data is subjected to the reference magnification processing. The raster data subjected to the reference scaling process is output to the adjustment scaling process unit 72. The above processing is performed as an external setup (offline) work before the object 14 is exposed.

  When the exposure recording to the drawing object 14 is instructed after the outer setting work is completed or during the outer setting work, the drawing object 14 is set on the moving stage 19 at the position shown in FIG. 1 in S12. Is done. In S13, the stage drive unit 74 is driven by the control device 13, and the moving stage 19 is moved toward the second gate 25 at a constant speed in the Y direction.

  The moving stage 19 is moved in the Y direction and passes directly under the second gate 25. At this time, the drawing object 14 on the moving stage 19 is photographed by the camera 27 in S14. An imaging signal obtained by the camera 27 is output to the position detection unit 75. The position detection unit 75 converts the digital image data. In S <b> 15, the position detection unit 75 detects the position of the alignment mark 15 of the drawing object 14 on the moving stage 19 based on the image data, the position of the camera 27 in the X direction, and the shooting timing thereof. The detection result of the position detector 75 is output to the control device 13.

  In the control device 13, the detection result of the alignment mark 15 from the position detection unit 75 is analyzed, and the deviation amounts of the drawing object 14 in the X direction, the Y direction, and the θ direction with respect to the reference position on the moving stage 19, and the object to be detected. A deviation amount from the reference size of the drawing body 14 is calculated. Next, as shown in S16, the adjustment magnification and the correction amount of the frame data are calculated from the calculated shift amount. The calculated adjustment scaling factor and frame data correction amount are output to the adjustment scaling processing unit 72 and the frame data generation unit 73, respectively.

  Next, in S <b> 17, the adjustment scaling process unit 72 performs the adjustment scaling process according to the adjustment scaling ratio from the control device 13 on the raster data from the RIP 71. The raster data subjected to the adjustment scaling process is output to the frame data generation unit 73, and is converted into frame data corresponding to each exposure head 22 by the frame data generation unit 73 as shown in S18. At this time, the frame data is corrected in accordance with the correction amount from the control device 13 so that the exposure is performed at the same position as when no deviation has occurred. The generated frame data is output to the DMD driver 41 of the corresponding exposure head 22. When the generation of the frame data is finished, as shown in S19, the moving stage 19 is moved toward the original position at the same speed as shown in S19, and the light source unit 11 is driven by the control device 13 in S20. Then, exposure recording by the exposure unit 20 is started.

  The frame data output to the DMD driver 41 is sequentially written into the SRAM cell according to the position in the Y direction of the moving stage 19 measured by the length measuring device 26. As a result, the charge state of the SRAM cell is switched depending on the frame data to be written, and the inclination angle of the micromirror 61 is changed, so that the reflection direction of LB from the light source unit 11 given through the optical fiber 23 and the incident optical system 30 is also changed. Changed. That is, the LB from the light source unit 11 is optically modulated according to the frame data by the optical modulation unit 31 configured by the DMD 40 or the like.

  The LB modulated by the light modulator 31 is enlarged to a predetermined magnification by the first emission optical system 32, sharpened by the microlens 45, and incident on the aperture array 34. Then, the aperture array 34 further sharpens and prevents unnecessary light from passing due to chattering of the micromirror 61.

  The LB that has passed through the aperture array 34 is magnified to a predetermined magnification by the second emission optical system 35 or is incident on the prism pair 49 with the same magnification, and the prism pair 49 performs focus adjustment. The LB whose focus has been adjusted by the prism pair 49 is irradiated onto the drawing object 14 on the moving stage 19, whereby a desired image is exposed and recorded on the drawing object 14.

  After the exposure recording on one drawing object 14 is completed, if there is a next drawing object 14 (Yes in S21), the drawing object 14 on which the exposure recording is completed is moved from the moving stage 19 as shown in S22. At the same time, the process returns to S12, the next drawing object 14 is set on the moving stage 19, and the following steps such as the adjustment scaling process are repeated. In other words, the adjustment scaling process is performed each time the drawing target 14 is replaced and exposure recording is performed.

  On the other hand, when there is no next drawing object 14 (no in S21) and the replacement of vector data is instructed (yes in S23), the drawing object 14 suitable for the exchanged vector data is prepared, and in S10 Returning, the following steps such as rasterization and reference scaling processing are repeated. If the replacement of vector data is not instructed (no in S23), the process is terminated. That is, the reference scaling process is not performed until the vector data is replaced, and is performed only once for each input of vector data.

  As described above, the electronic scaling process applied to the raster data in accordance with the size of the drawing object 14 is divided into the reference scaling process and the adjustment scaling process in two stages. Can be obtained, and the subsequent fine adjustment can be performed by the adjustment scaling process.

  Since the standard scaling process is performed as an external setup operation, the only process that affects the exposure time is the adjustment scaling process performed as an internal setup work, but most of the electronic scaling processes have been completed in the standard scaling process. Thus, the adjustment scaling process is an extremely small scaling ratio, that is, a process of approximately equal magnification, so that an increase in exposure time can be minimized. Further, the adjustment scaling processing unit 72 may be of a scale that can handle processing with a very small scaling ratio, and does not require a large-scale configuration.

  Since the function of the reference scaling processing unit 76 is realized by software, it is possible to perform electronic scaling processing with a high degree of freedom, such as using a program including an algorithm that suppresses image quality degradation due to pixel interpolation or thinning out as much as possible. In addition, due to the dramatic progress of advanced technology in recent years, there is a concern that the contents of the electronic scaling processing described in the program will become obsolete, but the function of the reference scaling processing unit 76 is realized by software. If this is the case, a flexible response can be taken such as creating a new program and upgrading.

  Since the function of the adjustment scaling processing unit 72 is constructed by hardware, electronic scaling processing is faster than in the case of software. For this reason, it can contribute to the reduction of the further exposure time. However, if the function of the adjustment scaling unit 72 is constructed by hardware, the above-mentioned advantage of the software (suppression of image quality deterioration) is lost, but the adjustment scaling process is a process with a very small scaling factor. The effect of image quality degradation is less than that of the standard scaling process, and therefore the advantage of speeding up the electronic scaling process is far greater than the negative effects of using hardware. In other words, the realization of the function of the reference scaling processing unit 76 by software and the construction of the function of the adjustment scaling processing unit 72 by hardware make full use of the advantages of the software and hardware. It can be said that this is the mode.

  Since the reference scaling process is performed by adjusting the RIP resolution when rasterizing with the RIP 71, it is possible to perform the electronic scaling process with little variation in the line width of the drawing pattern.

  In the above embodiment, the DMD 40 is shown as the spatial light modulation element. However, the spatial light modulation element is not limited to this, and for example, an SLM (Special Light Modulator), a liquid crystal optical shutter, and a PLZT (Piezo-electric Lanthanum). -modified lead Zirconate Titanate) element may be used. Further, in the above-described embodiment, the drawing object 14 on which a photosensitive material is applied or stuck as an exposure target is shown. However, for example, a photographic film or photographic paper may be used. Furthermore, in the above-described embodiment, an example in which the present invention is applied to the digital exposure system 2 has been described. However, for example, the present invention may be applied to a system that performs exposure by deflecting and reflecting a light beam with a polygon mirror.

It is a perspective view which shows schematic structure of a digital exposure system. It is explanatory drawing which shows schematic structure of an exposure head. It is a perspective view which shows schematic structure of DMD. It is a block diagram which shows the internal structure of a digital exposure system. It is a schematic diagram for demonstrating a reference | standard variable magnification. It is a flowchart which shows the operation | movement procedure of a digital exposure system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Digital exposure system 10 Digital exposure machine 11 Light source unit 12 Image processing unit 13 Control apparatus 14 Drawing object 15 Alignment mark 20 Exposure part 22 Exposure head 27 Camera 40 DMD
71 RIP
72 Adjustment scaling processing unit 75 Position detection unit 76 Reference scaling processing unit

Claims (8)

In an image recording system that directly draws a predetermined drawing pattern represented by digital data on a plurality of drawing objects,
First scaling processing means for applying a first electronic scaling process to the digital data at a first scaling factor common to the plurality of objects to be drawn;
In a different second magnification individual of the plurality of the drawing member, and a second variable scale magnification process means for performing a second electronic magnification processing on the digital data,
A second deviation amount measuring means for actually measuring the deviation amount from the reference size of the drawing object ,
The second scaling factor is set based on the first scaling factor and an actual measurement value of the deviation amount by the second deviation amount measuring means,
The first and second scaling processing means correct the recording position shift of the drawing pattern due to the shift from the reference size of the drawing object by the first and second electronic scaling processing. An image recording system characterized by the above. The first scaling process means performs the first electronic scaling process as an external setup work before drawing the drawing pattern on the drawing object,
2. The second scaling process according to claim 1, wherein the second scaling process unit performs the second electronic scaling process as an internal setup operation while the drawing pattern is being drawn on the drawing object. The image recording system described.   The first scaling factor is set based on an average value of deviation amounts from a reference size of the drawing object, or an intermediate value between maximum and minimum values. Image recording system.   The image recording system according to claim 3, wherein the average value or the intermediate value is obtained empirically from a past production record of the drawing object. A first deviation amount measuring means for actually measuring the deviation amount from the reference size of the drawing object;
5. The image recording system according to claim 3, wherein the average value or the intermediate value is obtained from an actual measurement value of the deviation amount by the first deviation amount measuring unit. The first scaling unit is realized by software,
The second variable magnification processing means, an image recording system according to any one of claims 1 to 5, characterized in that it is realized the function in hardware. A raster image processor that rasterizes vector data of the drawing pattern and generates raster data as the digital data;
It said first flexure magnification process unit, by adjusting the RIP resolution during the rasterization, in any one of claims 1 to 6, characterized by applying said first electronic variable scale magnification process in the raster data The image recording system described. In an image recording method for directly drawing a predetermined drawing pattern represented by digital data on a plurality of drawing objects,
A first scaling process step of applying a first electronic scaling process to the digital data at a first scaling factor common to the plurality of objects to be drawn;
A second scaling step of performing a second electronic scaling process on the digital data at a second scaling factor that is different for each of the plurality of drawing objects;
A deviation amount measuring step of actually measuring the deviation amount from the reference size of the drawing object ,
The second scaling factor is set based on the first scaling factor and an actual measurement value of the deviation amount actually measured in the deviation amount measurement step,
In the first and second scaling processing steps, the first and second electronic scaling processing corrects a shift in the recording position of the drawing pattern caused by a shift from the reference size of the drawing target. An image recording method characterized by the above.

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