JP2005266779A - Exposure apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an exposure apparatus which can reduce the time required from measuring the focus of an exposure beam to starting exposure and can improve productivity. <P>SOLUTION: When a photosensitive material 150 set on a stage 152 in the exposure apparatus 100 passes below a scanner 162 while the stage 152 moves along a guide 158, the exposure face 56 is scanned and exposed to laser light irradiating from the scanner 162. A CCD camera 182 for alignment measurement is disposed in the upstream side of the scanner so as to detect the reference of the exposure position laid on the photosensitive material 150 by use of the exposure on the photosensitive material 150. A displacement sensor 184 for focus measurement to measure the distance from the exposure face 56 is disposed near the CCD camera 182. Thereby, distance measurement by the displacement sensor 184 can be carried out simultaneously with detection of the reference part by the CCD camera for the exposure operation of the exposure apparatus 100, which can decrease the distance required to move the photosensitive material 150 from the position where the reference part is detected to the position where exposure starts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus and method, and more particularly to an exposure apparatus and method for exposing a photosensitive material with a light beam modulated by a spatial modulation element or the like according to image information.

  Conventionally, various exposure apparatuses that use a spatial light modulation element (SLM) such as a digital micromirror device (DMD) to perform image exposure with a light beam modulated according to image data (image information) have been proposed. ing.

  For example, the DMD is a mirror device in which a large number of micromirrors whose reflecting surfaces change in response to a control signal are two-dimensionally arranged on a semiconductor substrate such as silicon. FIG. In the exposure apparatus 300 of the conventional digital scanning exposure method (maskless exposure method) shown, a light source that emits laser light, a lens system that collimates the laser light emitted from the light source, and a substantially focal position of the lens system are arranged. Each of the DMD micromirrors is turned on / off by a control signal generated in accordance with image data or the like by an exposure head (scanner) 302 equipped with DMD and a lens system that forms an image of the laser light reflected by the DMD on the scanning surface. The laser beam is modulated by control, and the modulated laser beam is set on the stage 304 and moved along the scanning direction to the photosensitive material 306. It is doing the image exposed.

  In addition, the exposure apparatus 300 follows an alignment function that corrects an exposure position deviation (X, Y direction) with respect to the photosensitive material 306 and a variation in waviness and thickness (Z direction) of the photosensitive material 306. Is provided with an autofocus function for focusing the laser beam, and the position (X, Y direction) of the photosensitive material 306 is measured upstream of the exposure head 302 in the moving direction of the photosensitive material 306. An alignment CCD camera 308 for detecting an alignment mark, a reference hole, or the like provided on the photosensitive material 306 is provided as a reference portion for use, and is located near the exposed surface of the photosensitive material 306 in the vicinity of the upstream side of the exposure head 302. An autofocus displacement sensor 310 for measuring the distance (Z direction) is provided. In the exposure operation, before exposure, the position of the photosensitive material 306 is measured by the CCD camera 308 (detection of the alignment reference portion), and the exposure position deviation is corrected by laser light based on the obtained measurement information. After the alignment measurement is completed, a distance measurement (focus measurement) from the exposed surface of the photosensitive material 306 by the displacement sensor 310 is performed, and a focus mechanism provided on the laser light emission side of the exposure head 302 is based on the acquired measurement information. The exposure position by the laser beam and the accuracy of the focus position are used or the exposure head 302 is moved and adjusted in the direction of the optical axis, and exposure is performed while performing autofocus control so that the focal point of the laser beam coincides with the surface to be exposed. We are trying to improve.

  Various techniques for correcting the focus of the exposure beam have been proposed in exposure apparatuses using a mask exposure method. For example, a mask stage that scans a mask on which a pattern is formed in a predetermined direction and a substrate stage that scans the substrate in a predetermined direction in synchronization with the mask stage, and sequentially exposes the mask pattern onto the substrate. In a scanning exposure apparatus, a projection optical system for projecting an image of a mask pattern onto a substrate, detection means for detecting focus information of the substrate at a plurality of measurement points during scanning of the substrate, and scanning of the substrate Adjusting means (Z leveling) for adjusting the positional relationship between the image plane of the projection optical system and the substrate based on the focus information detected by the detecting means in accordance with a change in the shape of the exposure illumination field (exposure area) on the substrate in the middle Stage), even when the shape of the exposure region changes during the exposure operation, the exposure surface of the moving substrate (wafer coated with a photoresist or the like) is exposed. By controlling the tracking of the locus position in an appropriate state, it is possible to balance the holding of the exposure surface of the substrate within the depth of focus and the prevention of image deterioration, and to perform optimum autofocus and autoleveling control. There is technology that can be done. Further, in this exposure apparatus, the adjustment means sequentially obtains an approximate surface of the exposure surface of the substrate in the exposure illumination field on the substrate based on the focus information detected by the detection means during the scanning of the substrate, and the projection optical system The positional relationship between the substrate and the image plane of the projection optical system is adjusted so that the image plane and the approximate plane of the exposure surface of the substrate substantially coincide (for example, see Patent Document 1).

Further, in synchronization with the scanning movement of the mask in the first direction with respect to the exposure beam, the substrate is scanned and exposed in the second direction with respect to the exposure beam that has passed through the projection optical system. In the projection exposure apparatus, a measuring unit that measures focus position information regarding a partial area on the substrate, and a surface position setting unit (Z leveling stage) that sets the surface position of the substrate based on the focus position information measured by the measuring unit; And the surface position setting means, before the partial area reaches the irradiation area, so that the partial area on the substrate is exposed in a focused state when it reaches the irradiation area of the exposure beam that has passed through the projection optical system, By gradually moving the surface position of the substrate based on the measured focus position information, the exposure surface of the photosensitive substrate can be aligned with the image plane of the projection optical system with high accuracy. There is a technology in so that (for example, see Patent Document 2).
Japanese Patent No. 3305448 Japanese Patent No. 338258

  However, in the exposure apparatus 300 of the conventional digital scanning exposure method described above, the displacement sensor 310 is disposed between the photosensitive material 306 moved to the alignment measurement completion position (position 306B in FIG. 18) and the exposure head 302, and the alignment is performed. Since the image is exposed by the exposure head 302 while performing focus measurement by the displacement sensor 310 after the measurement is completed, the distance by which the photosensitive material 306 is moved from the alignment measurement completion position to the exposure start position (directly below the exposure head 302). It becomes long and the productivity is lowered due to the travel time. Here, in order to increase productivity, it is preferable to bring the focus measurement position (displacement sensor 310) as close as possible to the exposure position (exposure head 302). However, this has physical limitations, and for this purpose, displacement is also required. The measurement apparatus including the sensor 310 needs to be downsized and have a complicated layout.

  On the other hand, in the mask exposure type exposure apparatus described in Patent Documents 1 and 2, the substrate side is moved in the focus depth direction using the Z leveling stage in order to correct the focus of the exposure beam. There is a problem that the configuration of the apparatus becomes complicated and the entire apparatus becomes large.

  In view of the above facts, an object of the present invention is to provide an exposure apparatus and method that can improve the productivity by reducing the time taken from the exposure beam focus measurement to the start of exposure. It is another object of the present invention to provide an exposure apparatus and method that can be realized without simplifying the configuration and increasing the size of the entire apparatus.

  In order to achieve the above object, the invention according to claim 1 is directed to an exposure unit that scans and exposes a photosensitive material with a light beam modulated in accordance with image information, and the exposure unit and the photosensitive material along the scanning direction. Moving means for relatively moving in the direction, reference portion detecting means for detecting a reference portion of an exposure position provided on the photosensitive material with respect to the photosensitive material moved relative to the exposure means by the moving means, and the reference portion detection A distance measuring means provided in the vicinity of the means for measuring the distance from the exposed surface of the photosensitive material, and correction control of the exposure position deviation by the light beam based on detection information by the reference portion detecting means, and Control means for performing focus control for matching the focal position of the light beam with the surface to be exposed based on information measured by the distance measuring means.

  In the first aspect of the present invention, the exposure means for scanning and exposing the photosensitive material with the light beam modulated in accordance with the image information and the photosensitive material are relatively moved by the moving means in the direction along the scanning direction. For this photosensitive material moved relative to the exposure means, the reference portion detection means detects the reference portion of the exposure position provided on the photosensitive material (alignment measurement). The distance measuring means provided in the vicinity of the reference portion detecting means measures the distance from the exposed surface of the photosensitive material simultaneously with the detection of the reference portion by the reference portion detecting means (focus measurement). The control unit performs correction control of the exposure position deviation by the light beam based on the detection information by the reference unit detection unit, and determines the focal position of the light beam based on the measurement information by the distance measurement unit. By performing the focus control to match the surface, the accuracy of the exposure position and the focal position by the light beam can be improved.

  Here, by providing the distance measuring means in the vicinity of the reference portion detecting means, the distance measurement means can measure the distance from the exposed surface of the photosensitive material simultaneously with the detection of the reference portion by the reference portion detecting means. Become. This makes it possible to shorten the distance that the photosensitive material is moved from the reference position detection completion position (alignment measurement completion position) to the exposure start position (directly below the exposure means), as compared with the conventional configuration. Productivity can be improved by shortening the time from measurement to the start of exposure.

  According to a second aspect of the present invention, in the exposure apparatus according to the first aspect, the exposure means is disposed on an exposure head that emits the light beam, and on the light beam emission side of the exposure head, and is wedged by a light transmitting material. A plurality of wedge-shaped optical members formed adjacent to each other along the optical axis of the light beam in directions opposite to each other, and at least one of the plurality of wedge-shaped optical members is formed into another wedge shape. Focusing means comprising: moving support means for supporting movement along a surface facing the optical member; and driving means for moving the wedge-shaped optical member supported by the movement support means along the facing surface; In the focus control, the driving unit is driven and controlled by the control unit.

  According to the second aspect of the present invention, when the control means drives and controls the drive means of the focus means provided in the exposure means in the focus control, the wedge-shaped optical member supported by the movement support means of the focus means is replaced with another wedge. It moves along the surface facing the optical member. Here, since the plurality of wedge-shaped optical members are arranged adjacent to each other along the optical axis of the light beam in directions reversed to each other, the incident surface on which the light beam is incident on one wedge-shaped optical member by the relative movement described above. And the relative distance in the optical axis direction of the light beam with respect to the exit surface that is transmitted through the plurality of wedge-shaped optical members and exits from the other wedge-shaped optical member after incidence is changed. The transmission distance transmitted through the optical member is changed, and the focal length of the light beam is changed.

  Such a focusing means can simplify the configuration and suppress an increase in the size of the entire apparatus as compared with a case where a mechanical means for moving the photosensitive material in the focus depth direction is used as in the prior art. .

  According to a third aspect of the present invention, in the exposure apparatus according to the first aspect, the exposure unit includes an exposure head that emits the light beam, and in the focus control, the control unit causes the exposure head to move the light beam. It is characterized by drive control so as to move in the direction of the optical axis.

  According to the third aspect of the present invention, the focal length of the light beam is changed by moving the exposure head provided in the exposure device in the optical axis direction of the light beam in the focus control. The movement of the exposure head can also change the focal length of the light beam, thereby moving the exposure head in the optical axis direction of the light beam without using, for example, an expensive optical member. Focus control can be executed by using a movement mechanism or the like having an inexpensive and simple configuration and controlling the movement mechanism or the like by a control means.

  According to a fourth aspect of the present invention, in the exposure apparatus according to the second or third aspect, the exposure means includes a plurality of the exposure heads.

  In the invention according to claim 4, if the exposure means has a plurality of exposure heads, the exposure area when the photosensitive material is exposed can be expanded by the light beams emitted from the plurality of exposure heads, respectively. It can be shortened to improve productivity.

  According to a fifth aspect of the present invention, in the exposure apparatus according to the fourth aspect, the focus control is performed by each of the plurality of exposure heads.

  According to the fifth aspect of the present invention, in the exposure of the photosensitive material by the exposure means having a plurality of exposure heads, the focus position of each light beam emitted from each exposure head is achieved by performing focus control with each of the plurality of exposure heads. However, each light beam coincides with the exposed surface of the photosensitive material. Thus, by improving the accuracy of the focal position for each light beam of the plurality of exposure heads, high-precision exposure can be realized when using a plurality of exposure heads.

  A sixth aspect of the present invention is the exposure apparatus according to any one of the first to fifth aspects, further comprising three or more distance measuring means arranged along a direction intersecting the scanning direction. It is characterized by that.

  According to the sixth aspect of the present invention, three or more distance measuring means are arranged along the direction intersecting with the scanning direction, and the distance measuring point with the exposed surface of the photosensitive material is 3 in the direction intersecting with the scanning direction. By setting it to be more than the number of locations, it becomes possible to measure the unevenness or undulation shape of the exposed surface due to the waviness or warpage of the photosensitive material in the direction intersecting the scanning direction. Thereby, in the focus control, the focal position of the light beam can be adjusted with high accuracy in accordance with the unevenness and the undulation shape of the exposed surface. Further, by increasing the number of distance measuring means, it is possible to measure the shape of the exposed surface in more detail, whereby the focal position of the light beam can be adjusted to the exposed surface with higher accuracy.

  According to a seventh aspect of the present invention, in the exposure apparatus according to the sixth aspect, the number of the distance measuring means is smaller than the number of the exposure heads.

  In the invention according to claim 7, when the exposure means has a large number of exposure heads, for example, three or more distance measurement means arranged along a direction that is smaller than the number of exposure heads and intersects the scanning direction. The approximate curve corresponding to the exposed surface of the photosensitive material is obtained based on the measurement information obtained by the above, and the relative movement between the exposure means and the photosensitive material is controlled so that the focal position of the light beam follows the approximate curve, etc. By focus control using a smaller number of distance measuring means than the exposure head, it is possible to adjust the focal position of each light beam to the exposed surface of the photosensitive material with high accuracy. In this way, even with a configuration in which the number of distance measuring means is smaller than the number of exposure heads, the accuracy of the focal position of each light beam can be improved, so the configuration of the exposure apparatus can be simplified.

  According to an eighth aspect of the present invention, in the exposure apparatus according to any one of the first to seventh aspects, the control unit creates mapping data based on the measurement information obtained by the distance measuring unit and performs the mapping. An approximate curve corresponding to the surface to be exposed is obtained based on the data, and focus control is performed so that the focal position of the light beam follows the approximate curve in the relative movement between the exposure unit and the photosensitive material. .

  In the invention according to claim 8, a plurality of distance measuring means are provided along the direction intersecting the scanning direction by aligning the focal position of the light beam with the approximate curve corresponding to the exposure surface obtained based on the mapping data. In the case of arrangement, the focal position of the light beam can be adjusted to the surface to be exposed with high accuracy without increasing the number of arrangement. Further, in the relative movement between the exposure unit and the photosensitive material, the light that is driven as the exposure unit and the photosensitive material are relatively moved by controlling the focus of the light beam following the approximate curve. The operations of the focus mechanism, the focus lens, etc. for adjusting the focal length of the beam are smooth. Thereby, the vibration of the exposure means is reduced, and the focal position accuracy of the light beam matched with the surface to be exposed can be further increased.

  According to a ninth aspect of the present invention, in the exposure apparatus according to any one of the first to eighth aspects, the photosensitive material is exposed when the measurement information by the distance measuring means exceeds a preset threshold value. The exposure means is controlled so as not to perform the operation.

  In the invention according to claim 9, the measurement information of the distance from the exposed surface of the photosensitive material measured by the distance measuring means has large irregularities or undulations on the exposed surface due to the waviness or warpage of the photosensitive material, or When a preset threshold value is exceeded due to a large thickness error of the photosensitive material, the control unit controls the exposure unit so as not to expose the photosensitive material. Thereby, the useless exposure time with respect to the inaccurate photosensitive material is reduced, and productivity can be improved. In addition, for example, if the exposure apparatus is configured or the exposure operation is controlled so as to complete the distance measurement of the entire exposure range on the exposed surface before the exposure of the photosensitive material by the exposure means, the accuracy is poor before the exposure. Since the exposure operation for the photosensitive material can be stopped, waste of the photosensitive material can be reduced.

  According to a tenth aspect of the present invention, the photosensitive material is moved relative to an exposure unit that emits a light beam modulated according to image information in a direction along a scanning direction, so that the photosensitive material is used by the light beam. An exposure method in which a photosensitive material is moved in a direction along the scanning direction, and an exposure position provided on the photosensitive material by a reference portion detection unit with respect to the moved photosensitive material. A reference part detecting step for detecting a reference part; and a distance measuring step for measuring the distance of the photosensitive material to be exposed to the exposed surface of the photosensitive material by a distance measuring means provided in the vicinity of the reference part detecting means; After the completion of the reference portion detection step and the distance measurement step, the exposure position deviation correction by the light beam is performed on the moved photosensitive material based on the detection information in the reference portion detection step. And an exposure step of performing scanning exposure of the photosensitive material by performing focus control to make the focal position of the light beam coincide with the surface to be exposed based on measurement information obtained by the distance measurement step. Yes.

  In the invention of claim 10, as in the invention of claim 1, the distance measurement means is provided in the vicinity of the reference portion detection means so that the distance measurement means can measure the distance from the exposed surface of the photosensitive material. This can be performed simultaneously with the detection of the reference portion by the portion detection means, and therefore, it is possible to improve the productivity by shortening the time taken from the focus measurement of the light beam to the start of exposure.

  According to an eleventh aspect of the present invention, in the exposure method according to the tenth aspect, in the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, and the reference portion detecting step is performed in the forward movement of the photosensitive material. The distance measurement step is performed, and the exposure step is performed in the return path movement of the photosensitive material.

  In the invention according to claim 11, by performing a plurality of steps such as reference portion detection, distance measurement, and exposure by reciprocating the photosensitive material, the plurality of steps are moved in only one direction. Compared with the case where it carries out, it can comprise the whole exposure apparatus small. Further, for example, in the case of having a moving means for moving the photosensitive material, a useless moving distance when the moving means is returned to the position before the start of exposure (origin position) is shortened. The productivity improvement effect is increased during mass production where continuous exposure is performed.

  According to a twelfth aspect of the present invention, in the exposure method according to the tenth or eleventh aspect, the exposure unit is controlled not to expose the photosensitive material when the measurement information exceeds a preset threshold value. It is characterized by doing.

  In the invention of the twelfth aspect, similarly to the invention of the ninth aspect, it is possible to improve the productivity by reducing the useless exposure time for the photosensitive material with poor accuracy, and also reduce the waste of the photosensitive material. it can.

  According to a thirteenth aspect of the present invention, the photosensitive material is moved relative to an exposure unit that emits a light beam modulated according to image information in a direction along a scanning direction, so that the photosensitive material is irradiated with the light beam. An exposure method that scans and exposes a photosensitive material in a direction along the scanning direction, and a distance measurement that measures a distance between the moved photosensitive material and an exposed surface of the photosensitive material And after completion of the distance measuring step, the exposure means is controlled not to expose the photosensitive material when the measurement information in the distance measuring step exceeds a preset threshold value, and the measurement information is Focus control is performed on the moved photosensitive material to match the focal position of the light beam with the exposed surface based on the measurement information when the threshold value is less than a preset threshold value. It is characterized by having, an exposure step of scanning exposure of the photosensitive material.

  In the invention described in claim 13, after completion of the distance measurement process for measuring the distance from the exposed surface of the photosensitive material, the exposure to the photosensitive material is performed when the measurement information in the distance measurement process exceeds a preset threshold value. By not performing the above, for example, as compared with the case where the photosensitive material is exposed while measuring the distance, the useless exposure time for the photosensitive material with poor accuracy can be reduced, and the productivity can be improved.

  According to a fourteenth aspect of the present invention, in the exposure method according to the thirteenth aspect, in the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, and the distance measuring step is performed in the forward movement of the photosensitive material. And the exposure step is performed in the backward movement of the photosensitive material.

  In the invention described in claim 14, when a plurality of steps such as distance measurement and exposure are performed by reciprocating the photosensitive material, the plurality of steps are performed by moving the photosensitive material only in one direction. Compared to the above, the entire apparatus can be made compact. Further, for example, in the case of having a moving means for moving the photosensitive material, a useless moving distance when the moving means is returned to the position before the start of exposure (origin position) is shortened. The productivity improvement effect is increased during mass production where continuous exposure is performed.

  According to a fifteenth aspect of the present invention, in the exposure method according to the thirteenth aspect, a reference portion of an exposure position provided in the photosensitive material is further detected with respect to the moved photosensitive material before the start of the exposure step. A reference portion detection step is provided, and the exposure step further corrects the exposure position deviation by the light beam based on detection information of the reference portion detection step for the photosensitive material moved after the reference portion detection step is completed. It is characterized in that the photosensitive material is scanned and exposed by controlling.

  According to the fifteenth aspect of the present invention, the accuracy of the exposure position by the light beam can be improved by performing correction control of the exposure position deviation by the light beam based on the detection information by the reference portion detection step.

  According to a sixteenth aspect of the present invention, in the exposure method according to the fifteenth aspect, in the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, and the distance measuring step and The reference portion detection step is performed, and the exposure step is performed in the backward movement of the photosensitive material.

  In the invention of the sixteenth aspect, similar to the invention of the eleventh aspect, by performing a plurality of processes such as distance measurement, reference portion detection, and exposure by reciprocating the photosensitive material, the entire exposure apparatus is made. It can be configured in a small size. Further, the useless moving distance when returning the moving means for moving the photosensitive material to the position before the start of exposure is shortened, and the productivity improvement effect is increased.

  Since the exposure apparatus and method of the present invention are configured as described above, productivity can be improved by shortening the time taken from exposure beam focus measurement to the start of exposure. Further, the configuration can be simplified and the entire apparatus can be realized without increasing the size.

  An exposure apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 shows an exposure apparatus according to the first embodiment of the present invention, and FIGS. 2 to 7 show an exposure head and a spatial light modulator applied to the exposure apparatus according to the present embodiment. .

  As shown in FIG. 1, the exposure apparatus 100 includes a rectangular thick plate-shaped installation base 156 supported by four legs 154. Two guides 158 extend along the longitudinal direction on the upper surface of the installation table 156, and a rectangular flat plate-like stage 152 is provided on the two guides 158. The stage 152 is arranged so that the longitudinal direction thereof faces the extending direction of the guide 158, is supported by the guide 158 so as to be reciprocally movable on the installation table 156, and is reciprocated along the guide 158 by being driven by a driving device (not shown). Moving. The photosensitive material 150 is sucked and held on the upper surface of the stage 152 in a state where the mounting position is determined by a positioning unit (not shown).

  Gates 160 and 161 are arranged at predetermined intervals on the upstream side and the downstream side in the moving direction of the stage 152 with respect to the center of the installation table 156. The gates 160 and 161 are formed in a U shape so as to straddle the moving path of the stage 152, and both end portions are fixed to both side surfaces of the installation table 156.

  In the gate 160 arranged on the upstream side in the moving direction of the stage 152, three detection units 180 are moved in the moving direction of the stage 152 on the upper part of the front surface (above the moving path of the stage 152) facing the upstream side. Are fixedly arranged at predetermined intervals along a direction orthogonal to the direction. In the detection unit 180, a CCD camera 182 disposed on the upstream side and a displacement sensor 184 disposed on the downstream side are integrated into a substantially box shape. The lens unit 186 of the CCD camera 182 and the displacement sensor 184 Both sensor parts 188 are directed downward.

  In the gate 161 arranged on the downstream side in the moving direction of the stage 152, the scanner 162 is fixedly arranged on the upper part of the rear surface facing the downstream side (above the moving path of the stage 152). The distance between the exposure head 166 and the detection unit 180 is such that an exposure start position by an exposure head 166 described later provided in the scanner 162 and a photographing position by the CCD camera 182 of the detection unit 180 (the optical axis center of the lens unit 186). Is set to be slightly longer than the longitudinal dimension of the photosensitive material 150.

  Further, the driving device of the stage 152, the scanner 162, and the detection unit 180 are connected to a controller 190 that controls them. By this controller 190, during the exposure operation of the exposure apparatus 100 described later, the stage 152 is controlled to move at a predetermined speed, the detection unit 180 is controlled to detect the photosensitive material 150 at a predetermined timing, and the exposure head 166 is controlled. The photosensitive material 150 is controlled to be exposed at a predetermined timing.

  As shown in FIGS. 2 and 3B, the scanner 162 includes a plurality of (for example, eight) exposure heads 166 arranged in an approximately matrix of m rows and n columns (for example, 2 rows and 4 columns). ing.

  As shown in FIG. 2, the exposure area 168 that is an area exposed by the exposure head 166 has a rectangular shape with a short side along the scanning direction, and is inclined at a predetermined inclination angle θ with respect to the scanning direction. . As the stage 152 moves, a strip-shaped exposed area 170 is formed for each exposure head 166 in the photosensitive material 150. As shown in FIGS. 1 and 2, the scanning direction is opposite to the stage moving direction.

  As shown in FIGS. 3A and 3B, the exposure heads 166 are arranged in a line, and each of the strip-shaped exposed areas 170 partially overlaps the adjacent exposed areas 170. Further, they are arranged at a predetermined interval (natural number times the long side of the exposure area, 1 time in the present embodiment) in the arrangement direction. Therefore, for example, the unexposed portion between the image region 168A located on the leftmost side of the first row and the image region 168C located on the right side of the image region 168A is the image located on the leftmost side of the second row. The area 168B is exposed. Similarly, a portion that cannot be exposed between the image area 168B and the image area 168D located on the right side of the image area 168B is exposed by the image area 168C.

  Each of the exposure heads 166A to 166H is a spatial light modulation element that modulates an incident light beam for each pixel in accordance with image data, as shown in FIG. 4 and FIGS. A digital micromirror device (DMD) 50 is provided. The DMD 50 is connected to the controller 190 having a scanner control unit including a data processing unit and a mirror drive control unit. The data processing unit of the controller 190 generates a control signal for driving and controlling each micromirror in the region to be controlled by the DMD 50 for each exposure head 166 based on the input image data.

  In addition, the mirror drive control unit controls the angle of the reflection surface of each micromirror of the DMD 50 for each exposure head 166 based on the control signal generated by the data processing unit. The control of the angle of the reflecting surface will be described later.

  On the light incident side of the DMD 50, a fiber array light source 66 including a laser emitting section in which emission ends (light emitting points) of an optical fiber are arranged in a line along a direction corresponding to the long side direction of the exposure area 168, a fiber A lens system 67 for correcting the laser light emitted from the array light source 66 and condensing it on the DMD, and a reflecting mirror 69 for reflecting the laser light transmitted through the lens system 67 toward the DMD 50 are arranged in this order.

  The lens system 67 includes a pair of combination lenses 71 that collimate the laser light emitted from the fiber array light source 66 and a pair of combination lenses that correct the light quantity distribution of the collimated laser light to be uniform. 73 and a condensing lens 75 that condenses the laser light whose light quantity distribution is corrected on the DMD. With respect to the arrangement direction of the laser emitting ends, the combination lens 73 spreads the light beam at a portion close to the optical axis of the lens and contracts the light beam at a portion away from the optical axis, and with respect to a direction orthogonal to the arrangement direction. Has a function of allowing light to pass through as it is, and corrects the laser light so that the light quantity distribution is uniform.

  As shown in FIG. 6, the DMD 50 is configured such that a micromirror 62 is supported on a SRAM cell (memory cell) 60 by a support column, and a large number of pixels (pixels) (for example, This is a mirror device formed by arranging micromirrors with a pitch of 13.68 μm, 1024 × 768) in a lattice pattern. Each pixel is provided with a micromirror 62 supported by a support column at the top, and a material having a high reflectance such as aluminum is deposited on the surface of the micromirror 62. The reflectance of the micromirror 62 is 90% or more. A silicon gate CMOS SRAM cell 60 manufactured in a normal semiconductor memory manufacturing line is disposed directly below the micromirror 62 via a support including a hinge and a yoke, and is entirely monolithic (integrated type). ).

  When a digital signal indicating the tilt state (modulation state) of the micromirror 60 is written in the SRAM cell 60 of the DMD 50 and further the digital signal is output from the SRAM cell 60 to the micromirror 62, the micromirror 62 supported by the support column. However, it is tilted in a range of ± α degrees (for example, ± 10 degrees) with respect to the substrate side on which the DMD 50 is disposed with the diagonal line as the center.

  FIG. 7 shows an example of a state in which a part of the DMD 50 is enlarged and the micromirror 62 is controlled to + α degrees or −α degrees, and FIG. 7A shows that the micromirror 62 is in an on state. FIG. 7B shows a state in which the micromirror 62 is tilted to −α degrees, which is an off state. As shown in FIGS. 7A and 7B, by controlling the inclination of the micromirror 62 in each pixel of the DMD 50 according to the image signal, the light beam incident on the DMD 50 is transmitted to each micromirror 62. Reflected in the tilt direction. Note that a light absorber (not shown) is arranged in the direction in which the light beam is reflected by the micromirror 62 in the off state. The on / off control of each micromirror 62 is performed by a scanner control unit including the above-described data processing unit and mirror drive control unit in response to a command from the controller 190.

  Further, on the light reflection side of the DMD 50, laser beams that have passed through the lens systems 54 and 58 and the lens systems 54 and 58 that form an image of the laser light reflected by the DMD 50 on the scanning surface (exposed surface) 56 of the photosensitive material 150. A focus mechanism 59 for adjusting the focal length of light is arranged in this order.

  The lens systems 54 and 58 are arranged so that the DMD 50 and the exposed surface 56 are in a conjugate relationship. In this embodiment, the laser light emitted from the fiber array light source 66 is made uniform and incident on the DMD 50. Then, each pixel is enlarged by about 5 times by these lens systems 54 and 58 and is set to be condensed.

  The focus mechanism 59 includes a pair of glass members (pair wedge glass) 210 and 212 formed in a wedge shape (trapezoidal column shape) with a transparent glass material. In the present embodiment, the refractive index: n of the glass members 210 and 212 is set to n = 1.53, and the pair of glass members 210 and 212 are adjacent to each other along the optical axis of the laser beam in an inverted direction. Has been placed.

  Specifically, the glass member 210 provided on the laser beam incident side (DMD 50 side) has a bottom surface directed to one side (above FIG. 5A) and a top surface parallel to the bottom surface on the other side. The plane that is directed to the lower side of FIG. 5A and perpendicular to the bottom surface and the top surface is disposed on the laser light incident side to form a light incident surface 210A. The tilted inclined surface is arranged on the laser beam emission side to form a light emission surface 210B, and the light incident surface 210A is substantially orthogonal to the optical axis of the laser beam emitted from the DMD 50 side. The surface 210B is arranged in an inclined direction.

  Further, the glass member 212 provided on the laser beam emission side (exposed surface 56 side) has a bottom surface directed to the other side (downward in FIG. 5A) and a top surface parallel to the bottom surface on one side. And a plane perpendicular to the bottom surface and the top surface is disposed on the laser beam emission side to form a light emission surface 212B, and is directed to the light emission surface 212B. The inclined surface inclined in this manner is disposed on the laser light incident side to form a light incident surface 212A, and the light emitting surface 212B is substantially orthogonal to the optical axis of the laser light emitted from the DMD 50 side. The incident surface 212A is arranged in an inclined direction.

  Then, as shown in FIGS. 5A and 5B, the pair of glass members 210 and 212 has a slight gap between the light emitting surface 210B of the glass member 210 and the light incident surface 212A of the glass member 212. In a non-contact state, the light incident surface 210A of the glass member 210 and the light emitting surface 212B of the glass member 212 are made parallel to each other and substantially orthogonal to the optical axis of the laser light as described above. In the present embodiment, the distance between the light exit surface 210B of the glass member 210 and the light incident surface 212A of the glass member 212 is set to 0.1 mm.

  FIG. 8 is an external view of the entire focus mechanism 59 including the glass members 210 and 212 described above.

  The focus mechanism 59 includes a base holder 214 and a slide holder 216 that individually hold each of the pair of glass members 210 and 212, and the base holder 214 disposed on the lower side in the orientation shown in FIG. The glass member 212 arranged on the laser beam emitting side is held, and in the orientation shown in FIG. 8, the glass holder 210 arranged on the laser beam incident side is held by the slide holder 216 arranged on the upper side. Yes.

  The base holder 214 has a wedge shape substantially similar to the glass member 212, and rectangular openings 218 and 220 are formed in the upper surface (inclined surface) 214 </ b> A and the lower surface 214 </ b> B, and a cavity for accommodating the glass member 212 therein. It is a substantially frame shape provided with a portion (accommodating portion) 222.

  The hollow portion 222 has a concave shape that is dug into the upper surface 214A side by a predetermined depth dimension in a substantially vertical downward direction. When the glass member 212 is accommodated, the hollow portion 222 is formed. The bottom surface and the inner peripheral surface are in contact with the lower surface (light emitting surface 212B) and the outer peripheral surface of the glass member 212 with almost no gap.

  The opening 220 on the lower surface 214B side is slightly smaller than the opening shapes of the opening 218 and the cavity 222 on the upper surface 214A side, and is disposed at the approximate center of the lower surface 214B. Further, a fixing portion 224 for fixing the entire focus mechanism 59 including the base holder 214 to the frame (not shown) of the scanner 162 is fixed to one end portion (left end portion in FIG. 8) of the lower surface 214B. Projected.

  On the other hand, the slide holder 216 has a wedge shape substantially similar to the glass member 210, and rectangular openings 226 and 228 are formed on the upper surface 216 </ b> A and the lower surface (inclined surface) 216 </ b> B, and the glass member 210 is accommodated therein. It is made into the substantially frame shape in which the cavity part (accommodating part) 230 was provided.

  The cavity 230 has a size of the opening 226 on the upper surface 214A side and is formed in a through hole shape that is dug substantially vertically downward and penetrates the opening 228 on the lower surface side, and when the glass member 210 is accommodated, The inner peripheral surface constituting the hollow portion 230 is sized to contact the outer peripheral surface of the glass member 212 with almost no gap.

  As shown in FIG. 8, the slide holder 216 has a lower surface 216 </ b> B facing the upper surface 214 </ b> A of the base holder 214, and an inclination direction of the lower surface 216 </ b> B is opposite to the upper surface 214 </ b> A of the base holder 214. A pair of guide rails 232 (on the front and rear end portions of the upper surface 214A of the base holder 214 and the lower surface 216B of the slide holder 216) disposed between the guide holders 232 (in FIG. 8, the rear guide rails). As a result, the base holder 214 is assembled into a unit.

  In the unitized state, the length of the slide holder 216 in the left-right direction in FIG. 8 is slightly shorter than that of the base holder 214, and the length of the slide holder 216 in the front-rear direction in FIG. It is substantially the same as 214 and is aligned so that the front end surfaces and the rear end surfaces thereof are substantially the same surface.

  The pair of guide rails 232 causes the upper surface 214A of the base holder 214 and the lower surface 216B of the slide holder 216 to be arranged substantially parallel to each other at a predetermined interval, and the slide holder 216 has a lower surface 216B and Relative movement in the left-right direction (in the direction of arrow S in FIG. 8) is possible along the inclination direction of the upper surface 214A. Further, at a predetermined position in the movement of the slide holder 216 (assembly position of the glass members 210 and 212), the cavity 230 of the slide holder 216 is a cavity of the base holder 214 in the plan view direction (arrow L direction) in FIG. It almost overlaps the portion 222.

  A rectangular frame plate-like glass member pressing plate 234 is fitted into and attached to the opening 226 on the upper surface 214A side of the slide holder 216. The outer shape of the glass member pressing plate 234 is set to fit into the opening 226 with almost no gap. In addition, the rectangular opening 236 formed in the approximate center of the glass member pressing plate 234 is approximately the same size as the opening 220 on the lower surface 214B side of the base holder 214, and the slide holder 216 is placed in the above-described manner. When it is moved to a predetermined position, it is disposed at a position that substantially overlaps the opening 220 in the plan view direction of FIG.

  Assembling of the glass members 210 and 212 and the glass member pressing plate 234 to the unitized base holder 214 and slide holder 216 moves the slide holder 216 to the predetermined position, so that the cavity 230 of the slide holder 216 is moved. The glass member 212, the glass member 210, and the glass member pressing plate 234 are assembled in this order in alignment with the cavity 222 of the base holder 214.

  The glass member 212 to be assembled first passes the opening 226 and the cavity 230 of the slide holder 216 with the inclined light incident surface 212A on the upper side and a predetermined orientation after the slide holder 216 is arranged at a predetermined position. It fits into the cavity 222 of the base holder 214. Here, in the glass member 212, the light emitting surface 212B directed downward is in contact with the bottom surface that forms the cavity 222, and the outer peripheral surface is in contact with the inner periphery that forms the cavity 222. It is accommodated in the cavity 222 of 214 without backlash.

  Subsequently, the glass member 210 is fitted into the cavity 230 of the slide holder 216 from the opening 226 with the inclined light emitting surface 210B on the lower side and a predetermined direction. Here, in the glass member 210, the light emitting surface 210 </ b> B directed downward is opposed to the light incident surface 212 </ b> A of the glass member 212 with a slight gap (0.1 mm), and the outer peripheral surface defines the cavity 230. The inner peripheral surface of the slide holder 216 is in contact with the inner peripheral surface of the slide holder 216 and is accommodated without play.

  Finally, the glass member pressing plate 234 is fitted into the opening 226 of the slide holder 216 in a predetermined direction, and the lower surface of the glass member pressing plate 234 is in contact with the light incident surface 210A of the glass member 210, not shown. The fixing member is fixed to the slide holder 216 with screws.

  With the above assembly, the pair of glass members 210 and 212 are individually held by the slide holder 216 and the base holder 214 in the adjacent state as shown in FIGS. 8 and 5A. Further, as the slide holder 216 moves, the glass member 210 moves in the arrow S direction along the surface direction of the light emitting surface 210B facing the light incident surface 212A of the glass member 212. Further, the laser light emitted from the DMD 50 side toward the glass members 210 and 212 enters the light incident surface 210A of the glass member 210 through the opening 236 of the glass member pressing plate 234, and causes the glass members 210 and 212 to enter. When transmitted, the light is emitted from the light exit surface 212B of the glass member 212 through the opening 220 on the lower surface 214B side of the base holder 214.

  Note that, when the glass members 210 and 212 are held by the base holder 214 and the slide holder 216, the inner peripheral surface of the hollow portions 222 and 230 and the outer peripheral surface of the glass members 210 and 212 are caused by variations in processing accuracy, temperature changes, and the like. There is a possibility that the gap (adhesion) exceeds the allowable range, and the glass members 210 and 212 may be loose. In that case, for example, a backlash removing mechanism including an elastic member such as a leaf spring or a compression coil spring is provided at a necessary portion of the inner peripheral surface constituting the hollow portions 222 and 230, and the glass member 210, 212 is energized to remove looseness, or a screw hole penetrating from an outer peripheral surface of the base holder 214 and the slide holder 216 to an inner peripheral surface constituting the hollow portions 222 and 230 and a push screw screwed into the screw hole are provided. A backlash removing mechanism may be provided at a necessary portion, and the glass members 210 and 212 may be pressed by this push screw to remove backlash.

  As shown in FIG. 8, an actuator mounting plate 238 is fixed with screws at a substantially central position on the right side surface 214 </ b> C of the base holder 214. The right side surface 214C of the base holder 214 is substantially perpendicular to the upper surface 214A, and the actuator mounting plate 238 attached to the right side surface 214C has a mounting portion (lower portion) in a direction substantially perpendicular to the upper surface 214A of the base holder 214. The actuator 240 is attached to the outer side surface of the upper portion of the upper portion of the slide holder 216 as a drive source for supplying the slide holder 216 with moving power.

  The actuator 240 is attached to the actuator mounting plate 238 such that the extending direction and moving direction (arrow D direction) of the drive shaft 242 are aligned with the moving direction (arrow S direction) of the slide holder 216, and the tip of the drive shaft 242 is attached. The part 242A is connected to the right side 216C of the slide holder 216. The actuator 240 is connected to a focus mechanism control unit of the controller 190, and is controlled by the focus mechanism control unit to operate.

  A notch 244 is formed at the right front corner of the upper surface 216 </ b> A of the slide holder 216. A pair of support posts 246 and 248 are erected on the bottom surface of the notch 244 and the right front corner of the upper surface 214 </ b> A of the base holder 214, and the drive shaft 242 of the actuator 240 is provided on the pair of support posts 246 and 248. A tension coil spring 250 having a spring force smaller than the driving force is installed. A preload is applied between the slide holder 216 and the base holder 214 connected via the guide rail 232 and the actuator 240 by the spring force of the tension coil spring 250.

  Here, when the actuator 240 is operated under the control of the focus mechanism control unit of the controller 190 and the drive shaft 242 is driven in the direction of the arrow D, the slide holder 216 and the glass member 210 are guided by the pair of guide rails 232 and the arrows. Move in the S direction. In addition, the slide holder 216 and the glass member 210 are loose in the stationary state due to the preload applied by the tension coil spring 250 even when there is some play (backlash) on the drive shaft 242 and the guide rail 232 of the actuator 240. It will be held without any movement, and will move smoothly when moving.

  A rectangular sensor mounting plate 252 is fixed to the right front corner of the lower surface 214B of the base holder 214 with screws. The sensor mounting plate 252 is attached to the mounting portion such that the right side portion protruding rightward from the mounting portion (left side portion) of the base holder 214 to the lower surface 214B is substantially parallel to the upper surface 214A of the base holder 214. The reference position sensor unit 254 for detecting the reference position (home position) of the slide holder 216 holding the glass member 210 is attached to the upper surface of the right side portion.

  In the reference position sensor unit 254, a photo sensor 258 is mounted on an upper part of a unit body having a rectangular parallelepiped shape, and a circuit board (not shown) that amplifies an electrical signal (detection signal) output from the photo sensor 258 inside the unit body. ) Is provided. The optical sensor 258 is provided with a light projecting / receiving element (not shown) on the inner wall surface of the slit portion 256, and the slit portion 256 is arranged in a direction substantially parallel to the moving direction (arrow S direction) of the slide holder 216. . The reference position sensor unit 254 is connected to a focus mechanism control unit of the controller 190, and is controlled and operated by the focus mechanism control unit.

  A reference position detection plate 260 corresponding to the reference position sensor unit 254 is fixed to the front end portion of the right side surface 216C of the slide holder 216 with screws. The reference position detection plate 260 is L-shaped, and the right side portion bent at a substantially right angle from the attachment portion (left side portion) to the right side surface 216C of the slide holder 216 and extended rightward by a predetermined length is the detection portion. The light detection unit is disposed at a position where the detection unit can pass through the slit 256 of the optical sensor 258 or be detached from the slit 256 as the slide holder 216 moves.

  Here, as the slide holder 216 moves, the tip of the detection part of the reference position detection plate 260 passes through the slit part 256 of the optical sensor 258 (arranged in the slit part 256) or leaves the slit part 256. The optical sensor 258 detects a light shielding / non-light shielding state by a light projecting / receiving element and outputs a High / Low detection signal corresponding to each state. Then, the reference position sensor unit 254 amplifies the detection signal by the circuit board and outputs it to the focus mechanism control unit of the controller 190.

  In addition, the focus mechanism control unit of the controller 190 controls the position at which the output level of the detection signal input from the reference position sensor unit 254 switches between High / Low when the slide holder 216 is moved by controlling the actuator 240. The reference position of the slide holder 216 and the glass member 210 is recognized, and information on the reference position is stored in the memory. In the drive control of the actuator 240, a control signal for driving and controlling the actuator 240 is generated based on the reference position information, and the control signal is generated by correcting the reference position information as necessary. Output to 240.

  The focus mechanism 59 is configured as described above. In the adjustment of the focal length of the laser beam by the focus mechanism 59, when the actuator 240 is driven and controlled by the focus mechanism control unit of the controller 190, the focus mechanism 59 is held by the slide holder 216. As shown in FIG. 9, the glass member 210 is moved from the reference position indicated by a two-dot chain line in the drawing to the direction of the arrow SA shown in FIG. 9A or the direction of the arrow SB shown in FIG. Moving.

  Here, when the glass member 210 is at the reference position, the distance between the light incident surface 210A of the glass member 210 and the light emitting surface 212B of the glass member 212, that is, the glass member 210 including a slight gap provided therebetween. , 212, where t is the total thickness dimension, the thickness dimension: t decreases by Δt (−Δt) when the glass member 210 is moved from the reference position in the direction of the arrow SA by a predetermined distance (−Δt). When 210 moves from the reference position in the direction of arrow SB by a predetermined distance, it increases by Δt (+ Δt).

  As described above, when the thickness dimension t of the glass members 210 and 212 changes (± Δt), the transmission distance through which the laser light passes through the glass members 210 and 212 changes, and the focal distance FD of the laser light changes. (± ΔFD). Note that PS shown in FIG. 9 represents an imaging plane.

  Further, assuming that the refractive index of the glass members 210 and 212 is n (n = 1.53 in the present embodiment), the focal length of the laser beam according to the amount of change in the thickness dimension t of the glass members 210 and 212: The amount of change in FD is obtained by the following equation.

+ ΔFD = + Δt − (+ Δt) / n
−ΔFD = −Δt − (− Δt) / n
Next, an exposure operation for the photosensitive material 150 by the exposure apparatus 100 configured as described above and data processing contents in the exposure operation will be described.

  First, when image data corresponding to an exposure pattern is input to the controller 190, it is temporarily stored in a frame memory in the controller. This image data is data representing the density of each pixel constituting the image by binary values (whether or not dots are recorded).

  Next, the photosensitive material 150 is set on the stage 152, and the operator performs an exposure start input operation from the operation unit of the controller 190. The photosensitive material 150 for performing image exposure by the exposure apparatus 100 includes a photosensitive epoxy resin or the like on the surface of a substrate or a glass plate as a material for forming a pattern (image exposure) such as a printed wiring board or a liquid crystal display device. In the case of a dry film, a laminate or the like is applied.

  When the exposure operation of the exposure apparatus 100 is started by the above input operation, the controller 190 controls the driving device, and the stage 152 starts moving at a constant speed from the origin position shown in FIG. . Each detection unit 180 is controlled and operated by the controller 190 in synchronization with the start of the movement of the stage or at a timing just before the leading edge of the photosensitive material 150 reaches just below the CCD camera 182 of the detection unit 180.

  When the photosensitive material 150 passes below the detection unit 180 as the stage 152 moves (moves from 150A to 150B in FIG. 10), alignment measurement by the CCD camera 182 and focus measurement by the displacement sensor 184 are simultaneously performed. Done.

  First, when the photosensitive material 150 passes under the three CCD cameras 182, as shown in FIG. 11A, each CCD camera 182 images the photosensitive material 150, and the captured image data (imaging image). Data) is output to the data processing unit of the controller 190.

  The data processing unit detects an alignment mark or a reference hole provided in the photosensitive material 150 as an alignment reference portion or an edge portion or a corner portion of the photosensitive material 150 as an alignment reference portion from the input photographing data. A proper exposure position with respect to the position and the exposed surface 56 is grasped. Then, at the time of image exposure by the scanner 162, which will be described later, correction control (alignment) is performed in which a control signal generated based on the image data of the exposure pattern stored in the frame memory is adjusted to the appropriate exposure position to perform image exposure. .

  Further, when the photosensitive material 150 passes below the three displacement sensors 184, each displacement sensor 184 is a distance between the front surface and the exposed surface 56 including detection of the rear end (edge detection processing) of the photosensitive material 150. Measurement is performed (see FIG. 11A), and the measured distance data (focus measurement data) is output to the scanner control unit of the controller 190.

  The scanner control unit recognizes the leading end and the trailing end of the photosensitive material 150 based on the input focus measurement data, and executes arithmetic processing for grasping the waviness and thickness dimension error of the photosensitive material 150. Further, based on this processing result, a control signal for driving and controlling the actuator 240 of the focus mechanism 59 of each exposure head 166 is generated and output to the scanner 162, and the focal position of the light beam irradiated from each exposure head 166 is determined. Focus control is performed to match the exposed surface 56 of the photosensitive material 150.

  Here, the contents of the above arithmetic processing and focus control will be described.

  Assuming that the moving direction of the photosensitive material 150 is the Y direction and the direction orthogonal to the moving direction (the width direction of the photosensitive material 150) is the X direction, the arithmetic processing in the Y direction is performed first by moving the photosensitive material 150 by the displacement sensor 184. Accordingly, a plurality of average values of distance data acquired at a predetermined movement interval are obtained. In this embodiment, as shown in FIG. 12A, the average calculation interval for calculating the average value of the distance data with the movement of the photosensitive material 150 is set to 1 mm, and the measurement interval is 200 μm, and the data is obtained every five times. Acquire and perform averaging.

  As shown in FIG. 12B, the scanner control unit of the controller 190 calculates a moving average value every time the photosensitive material 150 moves 1 mm in the Y direction (stage movement direction) from the measurement start position after the start of the measurement operation. Data (average value data of five measurements) is sequentially stored in the frame memory. As this moving average value data, data from the measurement start position to the measurement end position is stored.

  In addition, in order to remove noise data, data exceeding a preset measurement range is treated as not subject to averaging calculation processing, and clear data (invalid data) if this data continues for a predetermined number of times (for example, 15 times). ). For example, when a through hole is formed in the substrate of a printed wiring board serving as a photosensitive material and the through hole is detected, clear data is obtained. Clear data is also stored before the photosensitive material 150 reaches the measurement start position (before detection of the leading edge of the photosensitive material 150) and after passing through the measurement end position (after detection of the trailing edge of the photosensitive material 150). However, it is possible to specify in advance that the formation position of the corresponding region, such as a through hole, cannot be measured, or cancel the data of the corresponding region.

  Subsequently, the scanner control unit shifts each moving average value data stored in the measurement start direction by 1/2 of the average calculation interval (1 mm × 1/2 = 0.5 mm), and each averaging calculation measurement section. Is set as the Z coordinate value corresponding to the XY coordinate value of the intermediate point. Further, this Z coordinate value is mapped to each Y coordinate value and each X coordinate value that is the installation position of the three displacement sensors 184 to create mapping data as shown in FIG. A control signal for driving and controlling the focus mechanism 59 of each exposure head 166 is generated so that the focus of the irradiated light beam follows the approximate curve obtained from the mapping data.

  First, an approximate curve in the X direction is obtained by the following calculation process.

  As shown in FIG. 14, in the X direction cross section at a specific Y direction position (Y coordinate value obtained by shifting the moving average value data), the central portion of the photosensitive material 150 is warped so as to rise from both side ends. Three (X, Y, Z) coordinate values of the exposed surface 56 are acquired from the distance between the exposed surface and the displacement sensor measured by the three displacement sensors 184, and the following values are obtained from these coordinate values. The radius of curvature: R that applies to the equation (1) is derived.

(X-X0) 2+ (Z-Z0) 2 = R2 (1)
A curve (curvature circle) drawn by R calculated from the equation (1) becomes an approximate curve in the X-direction cross section of the exposed surface 56.

  Further, the distance in the X direction from the center of curvature (X0, Y0, Z0) of the approximate curve drawn by R to the optical axis L of the exposure head 166: HX, Z at the optical axis position of the exposure head 166 from the center of curvature to the approximate curve. When the directional distance is Z, the following equation (2) is established for R, HX, and Z.

R2 = HX2 + Z2 (2)
A Z coordinate value (Zn) at the optical axis position (Xn, Yn) of the exposure head 166 is obtained from Z calculated by the equation (2). Therefore, at (Xn, Yn), a control signal for driving and controlling the actuator 240 of the focus mechanism 59 of the exposure head 166 is generated so that the focal point of the light beam coincides with (Zn).

  Further, as shown in FIG. 12C, there is a curve obtained by connecting the Z coordinate value (Zn) at the optical axis position (Xn, Yn) of the exposure head 166 with each Y coordinate value obtained by shifting each moving average value data. , An approximate curve in the Y direction. The focus control accompanying the movement of the photosensitive material 150 in the Y direction is an actuator that smoothly moves the glass member 210 held by the slide holder 216 of the focus mechanism 59 so that the focal point of the light beam follows this approximate curve. 240 is driven and controlled. The above is the contents of arithmetic processing and focus control.

  Further, the scanner control unit determines whether or not the difference between the maximum value and the minimum value of the Z coordinate value exceeds a preset threshold value in the mapping data shown in FIG. 13, and determines that the threshold value is exceeded. In this case, it is determined that the waviness or thickness dimension error of the photosensitive material 150 is large and the accuracy is poor, and the controller 190 performs error control. In the error control, when it is determined that the photosensitive material 150 is inaccurate, the exposure is not immediately performed and the exposure operation is immediately stopped and the stage 152 is returned to the most upstream position. Then, information (error information) for notifying that the exposure operation is stopped is displayed on the monitor of the controller 190.

  When the photosensitive material 150 passes through the detection unit 180 (position 150B in FIG. 10), alignment measurement and focus measurement (simultaneous measurement) by the detection unit 180 are completed. Further, the photosensitive material 150 that has passed through the detection unit 180 moves toward the scanner 162 as the stage 152 moves. When the exposure material reaches the exposure start position, each exposure head 166 of the scanner 162 irradiates a light beam to irradiate the photosensitive material 150. Image exposure on the surface to be exposed 56 is started (see FIG. 11B).

  Here, the image data stored in the frame memory in the controller is sequentially read for each of a plurality of lines, and the data processing unit generates a control signal for each exposure head 166 based on the read image data. This control signal is subjected to correction of the exposure position deviation with respect to the photosensitive material 150 measured by the alignment by the correction control (alignment) described above. Then, the mirror drive control unit performs on / off control of each micromirror of the DMD 50 for each exposure head 166 based on the generated and corrected control signals.

  When laser light is emitted from the fiber array light source 66 to the DMD 50, the laser light reflected when the micromirrors of the DMD 50 are on is imaged on the exposed surface 56 of the photosensitive material 150 by the lens systems 54 and 58. Is done. Here, the focus of the laser beam is adjusted on the exposed surface 56 according to the distance between the exposed surface and the exposure head (lens system) at the exposure position by focus control performed using the focus mechanism 59 described above. .

  In this manner, the laser light emitted from the fiber array light source 66 is turned on / off for each pixel, and the exposed surface 56 of the photosensitive material 150 is exposed in a pixel unit (exposure area 168) that is substantially the same as the number of pixels used in the DMD 50. Is done. Further, when the photosensitive material 150 moves downstream together with the stage 152, the exposed surface 56 is scanned and exposed in the direction opposite to the stage moving direction by the laser beam. The exposed surface 56 is formed with a strip-shaped exposed region 170 that is scanned and exposed by the laser beam of each exposure head 166. In this scanning exposure, the focus of the laser beam is adjusted on the exposed surface 56 so as to follow the shape of the exposed surface 56 and follow the shape of the exposed surface 56 in synchronization with the scanning by focus control.

  When the photosensitive material 150 passes through the scanner 162 (position 150C in FIG. 10) and the image exposure of the photosensitive material 150 by the scanner 162 is completed, the stage 152 is driven in the reverse direction by the driving device, and the most upstream side along the guide 158 Return to the origin at. Thus, the exposure operation for the photosensitive material 150 by the exposure apparatus 100 is completed.

  Next, the operation of the exposure apparatus 100 according to the present embodiment described above will be described.

  In the exposure apparatus 100 according to this embodiment, a scanner 162 (each exposure head 166) that scans and exposes the photosensitive material 150 with a laser beam modulated according to image data, and the photosensitive material 150 are moved in the scanning direction by a stage 152. Move relative to the direction along. For this photosensitive material 150, the CCD camera 182 of the detection unit 180 detects the reference portion of the exposure position provided on the photosensitive material 150 (alignment measurement), and the displacement sensor 184 provided in the vicinity of the CCD camera 182 Simultaneously with the detection of the reference portion by the camera 182, the distance from the exposed surface 56 of the photosensitive material 150 is measured (focus measurement). The controller 190 performs correction control of the exposure position deviation by the laser light based on the detection information from the CCD camera 182, and the focal position of the laser light is exposed to the photosensitive material 150 based on the measurement information by the displacement sensor 184. By performing the focus control to match the surface 56, the accuracy of the exposure position and focal length by the laser beam can be improved.

  Further, since the displacement sensor 184 is provided in the vicinity of the CCD camera 182, the focus measurement can be performed simultaneously with the alignment measurement. As a result, the distance for moving the photosensitive material 150 from the reference portion detection completion position (alignment measurement completion position) to the exposure start position (directly below the scanner 162) is shorter than in the conventional configuration, from focus measurement to exposure start. Productivity is improved by shortening the time required for.

  In the present embodiment, when the controller 190 drives and controls the actuator 240 of the focus mechanism 59 provided in each exposure head 166 of the scanner 162 in the focus control, the glass member 210 supported by the slide holder 216 of the focus mechanism 59 is The light incident on the glass member 212 is moved along the light emitting surface 210B facing the light incident surface 212A of the glass member 212 with a slight gap, and the laser light emitted from the DMD 50 side enters the glass member 210 by this relative movement. The relative distance in the optical axis direction of the laser light changes between the surface 210A and the light exit surface 212B that passes through the glass members 210 and 212 after being incident and exits from the glass member 212, that is, the laser light is glass members 210 and 212. The transmission distance that passes through changes, and the focal length of the laser beam changes. It is.

  By using such a focus mechanism 59, the structure can be simplified and the overall size of the entire apparatus can be simplified as compared with the case of using mechanical means for moving the photosensitive material in the focus depth direction as in the prior art. Can be suppressed.

  In the present embodiment, the scanner 162 includes a plurality of (eight) exposure heads 166, so that the exposed surface 56 of the photosensitive material 150 is exposed by the laser light emitted from each of the plurality of exposure heads 166. Since the exposure area can be enlarged, the exposure time can be shortened and the productivity can be improved.

  In the present embodiment, in the exposure of the photosensitive material 150 by the scanner 162 having the plurality of exposure heads 166, the focus control is performed by the plurality of exposure heads 166, so that each laser beam emitted from each exposure head 166 is emitted. The focal position coincides with the exposed surface 56 of the photosensitive material 150 for each laser beam. Thus, by improving the accuracy of the focal position for each laser beam of the plurality of exposure heads 166, high-precision exposure can be realized when using the plurality of exposure heads 166.

  Further, in the present embodiment, three displacement sensors 184 are arranged along a direction (orthogonal direction) intersecting the scanning direction, and a distance measurement point with the exposed surface 56 of the photosensitive material 150 intersects the scanning direction. By using three locations in the direction, it is possible to measure the unevenness and the undulating shape of the exposed surface 56 due to the waviness or warpage of the photosensitive material 150 in the direction intersecting the scanning direction. Thereby, in the focus control, the focal position of the laser beam can be adjusted with high accuracy in accordance with the unevenness and the undulation shape of the exposed surface 56.

  In the present embodiment, the plurality of displacement sensors 184 are aligned along the direction intersecting the scanning direction by aligning the focal position of the laser light with the approximate curve corresponding to the exposed surface 56 obtained based on the mapping data. In the case of this embodiment, the number of the displacement sensors 184 (three) is smaller than the number of the exposure heads 166 (eight) in the present embodiment. Depending on the configuration, the focal position of the laser beam can be adjusted to the exposed surface 56 with high accuracy. In the relative movement between the scanner 162 and the photosensitive material 150, the focus control of the focus position of the laser beam is made to follow the approximate curve, so that the scanner 162 and the photosensitive material 150 are driven in accordance with the relative movement. The operation of the glass member 210 provided in the focus mechanism 59 for adjusting the focal length of the laser light is smooth. Thereby, the vibrations of the exposure heads 166 and the scanner 162 are reduced, and the focal position accuracy of the laser light matched with the exposed surface 56 can be further increased.

  Further, in the present embodiment, the measurement data of the distance from the exposed surface 56 of the photosensitive material 150 measured by the displacement sensor 184 has large irregularities or undulations on the exposed surface 56 due to the waviness or warpage of the photosensitive material 150. Alternatively, when a preset threshold value is exceeded due to a large thickness dimension error of the photosensitive material 150, the scanner control unit of the controller 190 controls the scanner 162 so as not to expose the photosensitive material 150. Thereby, the useless exposure time with respect to the photosensitive material 150 with poor accuracy is reduced, and the productivity can be improved. Further, as in the present embodiment, the exposure apparatus 100 whose configuration and exposure operation are controlled so that the distance measurement of the entire exposure range on the exposed surface 56 is completed before the exposure to the photosensitive material 150 by the scanner 162 is started. If this is the case, the exposure operation for the photosensitive material 150 with inaccurate accuracy is stopped before exposure, and waste of the photosensitive material 150 can be reduced.

(Second Embodiment)
15 and 16 show an exposure apparatus according to the second embodiment of the present invention. Note that in the exposure apparatus 200 according to the present embodiment, the same reference numerals are given to common portions with the first embodiment, and description thereof will be omitted.

  As shown in FIGS. 15 and 16, in the exposure apparatus 200, the longitudinal dimension of the installation table 202 is made shorter than that of the exposure apparatus 100 of the first embodiment, and the stage 152 moves reciprocally along the two guides 204. The movement range is narrowed. In the exposure apparatus 200, the origin position of the stage 152 is set at the right end of the installation table 202 shown in FIG. 16 (the origin position of the photosensitive material 150 is the 150D position in FIG. 16A). In the embodiment, the right side in FIG. 16 and the right back side in FIG. 15 will be described as the upstream side, and the left side in FIG. 16 and the left front side in FIG.

  A gate 161 to which the scanner 162 is attached is arranged at the upstream side in the moving direction of the stage 152 at the center of the installation table 202, and four displacement sensors 206 for focus measurement are provided in the vicinity of the downstream side of the gate 161, and A gate 160 to which three CCD cameras 208 for alignment measurement are attached is disposed.

  In this embodiment, the displacement sensor 206 and the CCD camera 208 are configured separately, and each displacement sensor 206 has a predetermined interval along the direction orthogonal to the moving direction of the stage 152 at the upper part of the upstream side surface of the gate 160. The CCD cameras 208 are arranged at predetermined intervals along the direction orthogonal to the direction of movement of the stage 152 on the upper part of the downstream side surface of the gate 160. Further, the gate 160 is disposed close to the gate 161 so that each displacement sensor 206 attached to the upstream side surface does not contact the downstream side surface of the gate 160.

  Next, an exposure operation for the photosensitive material 150 by the exposure apparatus 200 configured as described above will be described. The contents of the data processing in the exposure operation are the same as those in the first embodiment except that the number of acquired data in the alignment measurement is increased by adding one displacement sensor to the exposure apparatus 100 of the first embodiment. Therefore, explanation is omitted.

  When the operator performs an exposure start input operation from the controller 190, the stage 152 on which the photosensitive material 150 is set is driven by the driving device, and as shown in FIG. Starts moving at a constant speed. Each displacement sensor 206 and each CCD camera 208 are controlled and operated by the controller 190 in synchronization with the start of the movement of the stage or at a timing just before the leading edge of the photosensitive material 150 reaches just below the displacement sensor 206.

  When the photosensitive material 150 passes below the displacement sensor 206 and the CCD camera 208 as the stage 152 moves downstream (moves from 150D in FIG. 16A to 150E in FIG. 16B). The focus measurement by the displacement sensor 206 and the alignment measurement by the CCD camera 208 are performed simultaneously.

  These measurement operations are the same as those in the first embodiment. When the photosensitive material 150 passes below the four displacement sensors 206, each displacement sensor 206 includes detection of the leading edge and the trailing edge of the photosensitive material 150. The distance to the surface to be exposed 56 is measured, and the measured distance data is output to the scanner control unit of the controller 190. As in the first embodiment, the scanner control unit recognizes the leading edge and the trailing edge of the photosensitive material 150 based on the input focus measurement data, and grasps the waviness and thickness dimension error of the photosensitive material 150. Calculation processing including mapping data creation is executed, and based on the processing result, a control signal for driving and controlling the actuator 240 of the focus mechanism 59 of each exposure head 166 is generated and output to the scanner 162, and the image exposure by the scanner 162 is performed. Sometimes focus control is performed so that the focal position of the light beam emitted from each exposure head 166 coincides with the exposed surface 56 of the photosensitive material 150.

  Further, when the photosensitive material 150 passes below the three CCD cameras 208, each CCD camera 208 images the photosensitive material 150 and outputs the captured image data to the data processing unit of the controller 190. As in the first embodiment, the data processing unit detects an alignment reference portion provided on the photosensitive material 150 from the input photographing data, and performs appropriate exposure on the position of the photosensitive material 150 and the exposed surface 56. The position is grasped, and at the time of image exposure by the scanner 162, a control signal generated based on the image data of the exposure pattern is adjusted to the appropriate exposure position to perform correction control for image exposure.

  Further, in the focus measurement, as in the first embodiment, the difference between the maximum value and the minimum value of the Z coordinate value is preset by the scanner control unit based on mapping data created based on the focus measurement data (see FIG. 13). It is determined whether or not a certain threshold is exceeded. If it is determined that the threshold value is exceeded, error control is performed by the controller 190. This error control also displays error information on the monitor of the controller 190, stops the exposure operation, and moves the stage 152 from the downstream side to the most upstream side. The operation of returning to the origin position at is performed.

  When the photosensitive material 150 passes through the displacement sensor 206 and the CCD camera 208 (position 150E in FIG. 16B), alignment measurement and focus measurement (simultaneous measurement) are completed. Here, the stage 152 is driven in the reverse direction by the driving device, and moves upstream along the guide 204. Then, the photosensitive material 150 moves to the scanner 162 side as the stage 152 moves, and when the exposure start position is reached, each exposure head 166 of the scanner 162 irradiates a light beam to perform image exposure on the exposed surface 56 of the photosensitive material 150. (See FIG. 16B).

  Similarly to the first embodiment, this image exposure is also corrected for the exposure position deviation with respect to the photosensitive material 150 measured for alignment by correction control. The focus of the laser light emitted from each exposure head 166 is adjusted on the exposed surface 56 of the photosensitive material 150 according to the distance between the exposed surface and the exposure head at the exposure position by focus control. In synchronization with the scanning, the surface of the exposed surface 56 is adjusted so as to follow the shape of the exposed surface 56 smoothly.

  When the photosensitive material 150 passes through the scanner 162, the image exposure of the photosensitive material 150 by the scanner 162 is completed, and the stage 152 is directly driven upstream by the driving device and returns to the origin. Thus, the exposure operation for the photosensitive material 150 by the exposure apparatus 200 is completed.

  Next, the operation of the exposure apparatus 200 according to the present embodiment described above will be described.

  In the exposure apparatus 200 according to the present embodiment, as in the exposure apparatus 100 of the first embodiment, the displacement sensor 206 is provided in the vicinity of the CCD camera 208, thereby enabling simultaneous measurement of focus measurement and alignment measurement. Become. Thereby, the distance for moving the photosensitive material 150 from the reference portion detection completion position (alignment measurement completion position) to the exposure start position (directly under the scanner 162) can be shortened, and the time taken from the focus measurement to the exposure start can be shortened. And productivity can be improved. Further, in this exposure apparatus 200, the moving distance of the stage 152 when returning the photosensitive material 150 that has undergone image exposure to the origin position is short, and therefore the stage 152 in the exposure operation is compared with the exposure apparatus 100 of the first embodiment. The total movement distance is reduced (about 1/2). Accordingly, the productivity improvement effect is increased during mass production in which a plurality of photosensitive materials 150 are continuously exposed.

  Further, in the present embodiment, as in the first embodiment, a focus mechanism 59 for realizing focus control is used as compared with the conventional case where a mechanical means for moving the photosensitive material in the focus depth direction is used. The construction of the apparatus can be simplified and the overall size of the apparatus can be suppressed.

  In the present embodiment, similarly to the first embodiment, by using a scanner 162 having a plurality of exposure heads 166, the surface to be exposed of the photosensitive material 150 by the laser beams emitted from the plurality of exposure heads 166, respectively. The exposure area when exposing 56 can be expanded, the exposure time can be shortened, and the productivity can be improved.

  In the present embodiment, four displacement sensors 206 are arranged along the direction intersecting the scanning direction, and four distance measuring points with respect to the exposed surface 56 of the photosensitive material 150 are arranged in four directions intersecting the scanning direction. By doing so, the shape of the exposed surface 56 of the photosensitive material 150 can be measured in more detail than the exposure apparatus 100 of the first embodiment. Thereby, the focal position of the laser beam can be adjusted to the exposed surface 56 with higher accuracy. Also in this case, since the number of displacement sensors 206 (four) is smaller than the number of exposure heads 166 (eight), the configuration of the exposure apparatus 200 can be simplified.

  In the present embodiment, the focus control is performed so that the focal position of the laser beam follows the approximate curve corresponding to the exposed surface 56 obtained based on the mapping data in the same manner as in the first embodiment. The movement of the focus mechanism 59 driven as the scanner 162 and the photosensitive material 150 are moved relative to each other moves smoothly, and vibrations of the exposure heads 166 and the scanner 162 are reduced. The focal position accuracy of the laser beams to be matched can be further increased.

  In the present embodiment, similarly to the first embodiment, in the exposure operation, based on the measurement data of the distance from the exposed surface 56 of the photosensitive material 150 measured by the displacement sensor 206, the exposure to the photosensitive material 150 with poor accuracy is performed. By controlling the scanner 162 so as to stop the process, it is possible to reduce the useless exposure time for the photosensitive material 150 with poor accuracy and improve the productivity. The exposure apparatus 200 according to the present embodiment is also controlled by the exposure operation so that the distance measurement of the entire exposure range on the exposed surface 56 is completed before the exposure to the photosensitive material 150 by the scanner 162 is started. Previously, the exposure operation for the photosensitive material 150 with poor accuracy is stopped, and waste of the photosensitive material 150 can be reduced.

  Although the present invention has been described in detail with reference to the first and second embodiments described above, the present invention is not limited thereto, and various other embodiments are possible within the scope of the present invention. is there.

  For example, in the above-described embodiment, the exposure head provided with the DMD as the spatial modulation element has been described. However, as the spatial modulation element, for example, a micro electro mechanical systems (MEMS) type spatial modulation element (SLM) in addition to the DMD. A Spatial Light Modulator), an optical element (PLZT element) that modulates transmitted light by an electro-optic effect, a liquid crystal light shutter (FLC), or the like can also be used.

  The pair of glass members 210 and 212 provided in the focus mechanism 59 is configured to move the glass member 210 side while fixing the glass member 212 side in the above embodiment. The glass member 212 may be fixed and moved, or the glass members 210 and 212 may be moved together. Furthermore, the number of glass members provided in the focus mechanism 59 is not limited to two, and may be three or more. In that case, it is possible to adopt a configuration in which one glass member is fixed and the other glass members are movable, or all the glass members are movable.

  For the focus control of the laser light emitted from the exposure head 166, in addition to using the focus mechanism 59 as described in the above embodiment, for example, as shown in FIG. It is also possible to change the focal length of the laser beam by controlling the drive so that the laser beam is moved in the optical axis direction (arrow LZ direction in FIG. 17) and moving the exposure head 166 in the optical axis direction of the laser beam. is there. Thus, without using the expensive optical members such as the glass members 210 and 212 and the focus mechanism 59 described in the above embodiment, for example, when the focus movement amount is 1 mm, the exposure head 166 is made to emit laser light. Focus control can be executed by using a movement mechanism having an inexpensive and simple configuration that enables focus adjustment by moving 1 mm in the optical axis direction and controlling the movement mechanism by the controller 190.

1 is a perspective view showing an exposure apparatus according to a first embodiment of the present invention. 1 is a perspective view illustrating a configuration of a scanner according to a first embodiment of the present invention. (A) is a top view which shows the exposed area | region formed in a photosensitive material, (B) is a figure which shows the arrangement | sequence of the exposure area by each exposure head. 1 is a perspective view showing a schematic configuration of an exposure head according to a first embodiment of the present invention. (A) is sectional drawing of the subscanning direction along the optical axis which shows the structure of the exposure head shown in FIG. 4, (B) is a side view of (A). It is the elements on larger scale which show the structure of a digital micromirror device (DMD). (A) And (B) is explanatory drawing for demonstrating operation | movement of DMD. It is a perspective view which shows the structure of the focus mechanism which concerns on the 1st Embodiment of this invention. (A) And (B) is explanatory drawing for demonstrating operation | movement of the focus mechanism of FIG. (A) is a top view which shows the exposure operation | movement by the exposure apparatus of FIG. 1, (B) is a side view of (A). (A) is a side view showing a state of focus measurement by the exposure apparatus of FIG. 1, and (B) is a side view showing a state of focus control of laser light emitted from the exposure head. (A)-(C) is explanatory drawing for demonstrating the content of the arithmetic processing in the focus measurement and control by the exposure apparatus of FIG. It is a figure which shows the mapping data produced in the arithmetic processing in the focus measurement and control by the exposure apparatus of FIG. FIG. 2 is an explanatory diagram for explaining the content of obtaining an approximate curve in a cross section in the X direction of a surface to be exposed of a photosensitive material in focus measurement and control by the exposure apparatus of FIG. It is a perspective view which shows the exposure apparatus which concerns on the 2nd Embodiment of this invention. (A) is a top view which shows the exposure operation | movement by the exposure apparatus of FIG. 15, (B) is a side view of (A). (A) is sectional drawing of the subscanning direction along the optical axis which shows the modification of the structure for performing the focus control of the exposure head shown in FIG. 5, (B) is a side view of (A). (A) is a top view which shows the exposure operation | movement by the conventional exposure apparatus, (B) is a side view of (A).

Explanation of symbols

56 Surface to be exposed 59 Focus mechanism (focusing means)
100 exposure apparatus 150 photosensitive material 152 stage (moving means)
162 Scanner (exposure means)
166 Exposure head (exposure means / exposure head)
180 Detection unit 182 CCD camera (reference part detection means)
184 Displacement sensor (distance measuring means)
190 Controller (control means)
200 Exposure device 206 Displacement sensor (distance measuring means)
208 CCD camera (reference part detection means)
210 Glass member (wedge-like optical member)
210B Light exit surface (opposite surface)
212 Glass member (wedge-like optical member)
216 Slide holder (moving support means)
240 Actuator (drive means)

Claims (16)

Exposure means for scanning and exposing a photosensitive material with a light beam modulated in accordance with image information;
Moving means for relatively moving the exposure means and the photosensitive material in a direction along a scanning direction;
A reference part detecting means for detecting a reference part of an exposure position provided in the photosensitive material with respect to the photosensitive material moved relative to the exposure means by the moving means;
A distance measuring means provided in the vicinity of the reference portion detecting means for measuring the distance from the exposed surface of the photosensitive material;
Focus control for correcting the exposure position deviation by the light beam based on the detection information by the reference portion detection means, and for matching the focal position of the light beam to the exposed surface based on the measurement information by the distance measurement means Control means for performing
An exposure apparatus comprising: The exposure means includes
An exposure head for emitting the light beam;
A plurality of wedge-shaped optical members that are arranged on the light beam emission side of the exposure head, are formed in a wedge shape by a light transmitting material, and are arranged adjacent to each other along the optical axis of the light beam in an inverted direction; Moving support means for movably supporting at least one of the plurality of wedge-shaped optical members along a surface facing another wedge-shaped optical member; and the wedge-shaped optical member supported by the movement support means Driving means for moving along opposing surfaces; and focus means comprising:
Have
2. The exposure apparatus according to claim 1, wherein in the focus control, the driving unit is driven and controlled by the control unit.   2. The exposure unit according to claim 1, further comprising an exposure head that emits the light beam, wherein the focus control is driven and controlled by the control unit to move the exposure head in an optical axis direction of the light beam. The exposure apparatus described.   4. The exposure apparatus according to claim 2, wherein the exposure unit has a plurality of the exposure heads.   The exposure apparatus according to claim 4, wherein the focus control is performed by each of the plurality of exposure heads.   6. The exposure apparatus according to claim 1, further comprising three or more distance measuring units arranged along a direction intersecting the scanning direction.   7. The exposure apparatus according to claim 6, wherein the number of the distance measuring means is smaller than the number of the exposure heads.   The control means creates mapping data based on the measurement information from the distance measuring means and obtains an approximate curve corresponding to the exposed surface based on the mapping data. In relative movement between the exposure means and the photosensitive material, 8. The exposure apparatus according to claim 1, wherein focus control is performed so that the focal position of the light beam follows the approximate curve.   9. The control unit according to claim 1, wherein the control unit controls the exposure unit not to expose the photosensitive material when measurement information by the distance measurement unit exceeds a preset threshold value. The exposure apparatus according to claim 1. An exposure method in which the photosensitive material is scanned and exposed by the light beam by relatively moving the photosensitive material in a direction along a scanning direction with respect to an exposure unit that emits a light beam modulated according to image information. ,
A moving step of moving the photosensitive material in a direction along the scanning direction;
A reference part detection step for detecting a reference part of an exposure position provided on the photosensitive material by a reference part detection unit with respect to the moved photosensitive material;
A distance measuring step for measuring the distance of the photosensitive material to be moved by a distance measuring means provided in the vicinity of the reference portion detecting means;
After completion of the reference portion detection step and the distance measurement step, the moving photosensitive material is subjected to exposure position correction correction control by a light beam based on detection information in the reference portion detection step, and the distance measurement is performed. An exposure step of performing scanning exposure of the photosensitive material by performing focus control to match the focal position of the light beam with the exposed surface based on measurement information by the step;
An exposure method comprising:   In the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, the reference portion detecting step and the distance measuring step are performed in the forward movement of the photosensitive material, and the exposure step is performed in the backward movement of the photosensitive material. The exposure method according to claim 10, wherein the exposure method is performed.   12. The exposure method according to claim 10, wherein the exposure unit is controlled not to expose the photosensitive material when the measurement information exceeds a preset threshold value. An exposure method in which the photosensitive material is scanned and exposed by the light beam by relatively moving the photosensitive material in a direction along a scanning direction with respect to an exposure unit that emits a light beam modulated according to image information. ,
A moving step of moving the photosensitive material in a direction along the scanning direction;
A distance measuring step for measuring a distance between the photosensitive material to be moved and an exposed surface of the photosensitive material;
After the distance measurement step is completed, when the measurement information in the distance measurement step exceeds a preset threshold value, the exposure unit is controlled not to expose the photosensitive material, and the measurement information is preset. An exposure step of performing scanning exposure of the photosensitive material by performing focus control to match the focal position of the light beam with the exposed surface based on the measurement information for the moved photosensitive material when the threshold is less than or equal to the threshold value; ,
An exposure method comprising:   In the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, the distance measuring step is performed in the forward movement of the photosensitive material, and the exposure step is performed in the backward movement of the photosensitive material. The exposure method according to claim 13. Before the start of the exposure step, a reference portion detection step for detecting a reference portion of an exposure position provided in the photosensitive material is further provided for the moved photosensitive material,
In the exposure step, the photosensitive material moved after the completion of the reference portion detection step is subjected to correction control of the exposure position deviation by the light beam based on the detection information in the reference portion detection step, so that the photosensitive material is obtained. The exposure method according to claim 13, wherein scanning exposure is performed.   In the moving step, the photosensitive material is reciprocated in a direction along the scanning direction, the distance measuring step and the reference portion detecting step are performed in the forward movement of the photosensitive material, and the exposure step is performed in the backward movement of the photosensitive material. The exposure method according to claim 15, wherein the exposure method is performed.

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