JPH078583B2 - Drawing exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is realized by projecting a light beam on a surface of a photosensitive material and moving the light beam relatively, and modulating and controlling the light beam based on an image data signal. The present invention relates to a drawing exposure apparatus for exposing and recording the image pattern of.

[Conventional technology]

A device called a photoplotter, a pattern generator, or the like is known as the drawing exposure device as described above.

In these conventional devices, the shape of an image pattern to be recorded is obtained by a vector value based on XY coordinates, the photosensitive material and the light beam are relatively moved based on the vector value, and a light is emitted at a required position. By controlling blinking of the beam, a desired image pattern is exposed and recorded.

Further, in Japanese Patent Laid-Open No. 53-69701, a plurality of light beams are obliquely juxtaposed in the scanning direction, projected onto a photosensitive material to perform scanning exposure, and an exposure width in one scanning cycle is increased to increase a required area. A device for reducing the exposure time is described.

Further, as another means, the light beam is deflected by a deflecting means such as a rotating mirror or an oscillating mirror, and while being projected on the surface of the photosensitive material, the light beam is modulated and controlled by an image signal to expose and record an image pattern. Flying beam type plotters are also known.

[Problems to be Solved by the Invention]

The means for controlling the relative movement of the light-sensitive material and the light beam by the vector value has a relatively low movement speed and a large number of times of starting and stopping, so that the drawing time is long and the productivity is high. There is a low problem.

Further, since the line width of the recorded image line changes corresponding to the diameter of the light beam, it is possible to change the aperture diameter in the optical path of the light beam in order to record the image line of an arbitrary line width. The diameter of the light beam is controlled by means such as a replaceable variable aperture.

However, the variable aperture has a complicated mechanism and is problematic in terms of manufacturing and maintenance. Also, in the case of replacing multiple types of apertures, the position of each aperture can be accurately aligned with the optical axis of the light beam. It is difficult and there is a problem in drawing accuracy.

It is understood that the means described in the above-mentioned JP-A-53-69710 is intended to increase the drawing speed, but in this means, an aperture is arranged for each of a large number of light beams and The diameter of the light beam is regulated,
These apertures are arranged obliquely with respect to the operation direction in order to make the arrangement pitch of the light beams dense. Therefore, the projection points of each light beam are also arranged obliquely with respect to the scanning direction, and the timing of modulating and controlling each light beam must be finely adjusted for each light beam during scanning exposure. There is. Further, since a multi-channel acousto-optic modulator applied as a means for modulating a plurality of light beams is large in size corresponding to the number of channels, in order to downsize a device equipped with it,
The drawback is that the number of channels is limited to a relatively small number.

On the other hand, a flying beam type plotter is capable of high-speed writing, but the diameter of the light beam cannot be reduced to a certain extent or more, and when the photosensitive material is placed on a flat surface, the size of the projected light spot is small. It changes during the scanning stroke, it is not uniform, it is difficult to control the projection position, and the dimensional accuracy of the recorded image pattern is low,
There is a problem such as.

The present invention provides a drawing exposure apparatus which can solve the problems of the conventional apparatus and can record a duplicate image of high quality at high speed.

[Means for Solving the Problems]

A table that mounts a photosensitive material and reciprocates in the main scanning direction and an exposure head that moves in the sub-scanning direction orthogonal to the main scanning direction are supported by guide rails, respectively, and driven. A plurality of light beam groups in which light beams are arranged in a row at a required pitch in the sub-scanning direction are projected on a photosensitive material surface at a required distance along the main scanning direction, and scanning exposure is performed by a plurality of groups of light spot rows. ON / OFF modulation control of each light beam is performed based on a required image signal so that a duplicate image is exposed and recorded, and the position of each light beam in the plurality of light beam groups is sequentially sub-selected for each light beam group. In addition to arranging the light beams in the scanning direction with a phase shift, the image signal for controlling the modulation of the light beam group on the trailing side is delayed by the required time with respect to the leading side to perform scanning exposure, and the optical axis of the light beam projection position. Directional By detecting the motion and attached an automatic focusing device for automatically adjusting the position of the exposure head.

[Work]

Along with the movement of the table on which the photosensitive material is mounted and mounted, the light beam group which is arranged in a row crossing the table movement direction is modulated and controlled based on the control data obtained by converting the required image into an XY raster pattern. , A duplicate image is recorded on the photosensitive material with the arrangement pitch of beams in the light beam group as a unit pixel size.

Further, by sequentially shifting the relative phases of the respective light beams in the plurality of light beam groups by N / P, the scanning line density is increased and the quality of the recorded image is improved.

In addition, the attached automatic focus adjustment device copes with defocusing of the light spot due to vertical fluctuations of the photosensitive material surface caused by errors in the thickness of the photosensitive material and errors in the flatness of the mounting table surface. Then, the quality of the recorded image is improved.

〔Example〕

FIG. 1 is a perspective view showing the structure of a drawing exposure apparatus which is an embodiment of the present invention.

A guide rail (3) is fixedly mounted on the upper surface of a base plate (2) horizontally placed on a frame (1), and a table (4) is slidable on the guide rail (3) via an air bearing. Support. Hereinafter, the moving direction of this table (4) is set to Y.
The axial direction is defined as the X-axis direction.

A large number of vacuum suction holes (5) connected to a vacuum pump (not shown) are provided on the upper surface of the table (4) to adsorb and hold the photosensitive material (6) placed on the table (4).
In the following description, an example in which a glass dry plate having high dimensional stability is applied as the photosensitive material (6) will be mainly described.

On both sides of the guide rail (3) on the upper surface of the base plate (2),
The primary coil (7) (7) for the linear motor is installed, the magnetic body is attached to the corresponding position on the lower surface of the table (4) to form a linear motor, and the table (4) is driven in the Y-axis direction. . As a configuration of the linear motor, contrary to the above, a coil may be installed on the table (4) side and (7) and (7) on the base plate (2) side may be made of a magnetic material.

Further, linear scales (8) and (9) are installed in the Y-axis direction on both outer sides of the primary coils (7) and (7), respectively, and photoelectric sensors (10) mounted on the front and rear surfaces of the table (4) are engaged. Combined to form a linear encoder, table (4)
The pulse signals corresponding to the respective driving distances are output by driving.

The encoder on the front linear scale (9) generates a pulse having a coarse pitch for controlling the drive of the linear motor, and the encoder on the rear linear scale (8) controls an image signal described later. To generate a pulse with a fine pitch.

On the other hand, on the left side of the upper surface of the base plate (2), a pair of front and rear abutments (11) (12) are fixedly mounted, and a pair of left and right guide rails (13) (14) are erected in the X-axis direction, Guide rails (13)
A screw shaft (15) is supported between a pair of front and rear bearings (16) between (14) and is rotationally driven by a servomotor (17).

The sliding base (18) is supported on the upper surfaces of the guide rails (13) and (14) via air bearings, and the nut (not shown) installed on the lower surface is engaged with the screw shaft (15) to move in the X-axis direction. Drive to. An exposure head (20 ') including a light source section (19) and an optical system section (20) is mounted on the sliding base (18).

In addition, the linear scale (2
1) is installed in the X-axis direction, and a linear encoder is configured with a photoelectric sensor (not shown) mounted on the sliding base (18), and the sliding base (18) is driven to generate a pulse signal corresponding to the moving distance. Is output.

Next, FIG. 2 is a perspective view showing a configuration of a light source and an optical system. For convenience of explaining the traveling direction of the light beam and the moving direction of each part of the apparatus, the XYZ coordinate axes are shown with positive and negative signs in the lower part of the figure.

The light beam emitted from the laser light source (22) in the −Y direction is
The two mirrors (23) and (24) reflect in the + Y direction, and the beam splitter (25) splits it into two optical paths, one of which is directly connected to the beam expander (27A) and the other of which is a mirror. (26) Reflects the beam expander (27
B).

The two beam expanders (27A) and (27B) expand the incident light beams in the X-axis direction to form a flat light beam, and the next-stage multi-channel acousto-optic light modulator (hereinafter , AOM) (28A) and (28B).

The AOMs (28A) and (28B) divide the incident flat light beam into a large number of beams and individually turn on and off the light beams by a control signal. In this embodiment, 20
A channel-type AOM is applied to emit 20 modulated parallel light beams.

A group of 20 parallel light beams emitted from each of the AOMs (28A) and (28B) passes through aperture plates (29A) and (29B) in which a number of apertures corresponding to the number of light beams are arranged in series, and a mirror (30A) respectively. ) And (30B) and projected on the triangular prism (31).

The triangular prism (31) has a surface reflection treatment on the two surfaces of the right angle brium that cross the right angle, and each of the 20 points is projected from the top and bottom.
The parallel light beam group of the book is reflected in the + Y direction at a desired interval.

Then, each parallel light beam group is reflected by the mirror (32) in the −Z direction, and a reduction optical system including the lenses (33), (34) and the zoom lens (35) causes a minute light for scanning exposure. The point group (36) is projected and imaged on the photosensitive material (6), and scanning exposure is performed in the Y-axis direction by moving the table (4).

The light source (37), the lens (39a), the mirror (38), the lens (39b), the mirror (40) and the photoelectric element (41), which are installed in parallel with the reduction optical system, are glass dry plates which are photosensitive materials. Is a detection unit of the automatic focus adjustment device corresponding to the variation of the thickness of the above, which will be described later.

Next, FIG. 3 is a perspective view showing the structure around the triangular prism (31) in the above optical system.

Ejected from AOM (28A) and (28B), aperture plate (2
9A) and (29B) 20 parallel light beam groups (4
2A) and (42B) are triangular prisms (31) as described above.
Is incident on the slope from above and below, and is reflected in the + Y direction. At this time, if the position of the triangular prism (31) is moved in the Y-axis direction, the positions of the two parallel light beam groups after reflection in the Z-axis direction are vertically raised and lowered, and the distance between the two groups is increased or decreased. . That is, by arranging the triangular prism (31) so that it can move in the Y-axis direction, the light enters the lens (33) of the reduction optical system.
The distance (L) between the parallel light beam groups of the set can be set to an arbitrary amount.

FIG. 3 shows an example of a moving device for the triangular prism (31), which includes a holder (4) for holding the triangular prism (31).
3) is erected on the slide base (44), the slide base (44) is engaged with the base (45) by the dovetail groove so as to be slidable in the Y-axis direction, and by the pair of springs (46), -Y. It is biased in the direction.

The opposite end surface of the slide base (44) comes into contact with the tip of the screw shaft (48) screwed into the nut (47) standing on the base (45), and the screw shaft is attached by the attached knob (49). The sliding base (44) and the triangular prism mirror (31) held by the sliding base (44) move in the Y-axis direction by rotating the (48) forward and backward.

When the triangular prism (31) is moved in the + Y direction, the position where the upper and lower parallel light beam groups are reflected moves to the bottom side of the mirror (31) to increase the distance (L), and conversely moves in the -Y direction. Then, the reflection position shifts to the apex side of the mirror (31) and the distance (L) can be reduced.

FIG. 4 is a schematic diagram for explaining a formation state of a parallel light beam group in two sets of AOMs (28A) and (28B). Two elongated oval type (50A) (50B) is a light beam whose width is expanded by beam expanders (27A) (27B) and a number of squares (51-1) to (51-40) inside it. Shows 20 light beams each of A and B formed by multi-channel AOM (28A) (28B), the light beams of each light beam group are arranged at a pitch (P), and the first light beam Group (51-1) ~
(51-20) and the second light beam group (51-21) to (51-40) are shifted in phase in the X-axis direction by 1/2 of the pitch (P), that is, (P / 2). It is arranged.

To shift the phase of two light beam groups by (P / 2), 2
Pair the AOM (28A) (28B) with the corresponding aperture plate (29
A) and (29B) may be moved relative to each other in the X-axis direction.

FIG. 5 is a schematic diagram showing a light spot group obtained by projecting the two sets of light beam groups onto the glass dry plate (6) through the reduction optical system.

The first light spot group (52A) projected by the first light beam groups (51-1) to (51-20) is composed of light spots (52-1) (52-2). The second light spot group (52B) projected by the light beam groups (51-21) to (51-40) is a light spot (52-21) (52-2).
2) ... Two sets of light spots (52A) (52B)
Corresponding to the positional relationship of the light beam group on the incident side are arranged with a phase shift of 1/2 of the pitch (p) of the light spots in the X-axis direction.

Assuming that the reduction ratio in the reduction optical system is (m), the relationship between the arrangement pitch (p) of the light spots in each light spot group (52A) (52B) and the arrangement pitch (P) of the light beams in the light beam group is , P = m × p, and two sets of light spot groups (52A) (5A
The relationship between the distance (l) between 2B) and the distance (L) between the two sets of light beams entering the reduction optical system is L = m × l. In scanning exposure recording, in order to facilitate the timing control, the distance (l) of the light spot group is set to be an integral multiple of the unit pixel size (unit pixel pitch in the main scanning direction), and the triangular prism (31). It is desirable to adjust the position of (1) to set the distance (L) between the two sets of light beam groups.

As shown in FIG. 5, FIG. 6 is recorded when scanning exposure is performed with two sets of light spot groups which are arranged with their phases (the positions of the light beams for each light beam group) shifted by 1/2 pitch. 2A is a schematic diagram showing a state of an image according to the first embodiment, FIG. 7A shows a state in which an image contour line parallel to a row of light spot groups is recorded, and FIG. The solid line shows the pattern recorded by the light spot group and the dotted line shows the pattern recorded by the second set of light spots. In addition, FIG. 7 shows a state of an image recorded by the light spot group of only one row for comparison with this.

That is, when recording is performed with the light spot group of only one row, unevenness corresponding to the pitch of the light spots is formed in the image contour portion as shown in FIG. 7, and the contour line is particularly in the scanning direction as shown in (B). On the other hand, when it is inclined, the unevenness becomes remarkable, and the quality of the recorded image is significantly deteriorated. On the other hand, 1 / each other
When recorded by two sets of light spots arranged with a phase shift of 2 pitches, this defect is improved as shown in FIG.
High quality images can be recorded.

Although FIG. 6 shows the case of scanning and recording with two sets of light spot groups, a larger number of light spot groups may be applied in order to obtain a larger improvement effect. In that case, for example, in the case of 3 sets of light spot groups, the phase of each group is sequentially shifted by 1/3 pitch, and in the case of 4 sets of light spot groups, it is also shifted by 1/4 pitch, so that as a whole. Scanning lines can be arranged at an equal pitch.

Next, FIG. 8 is a front view of the automatic focusing device attached to the exposure head (20 ') as seen from the + Y direction.

The glass dry plate applied to the device of the present invention as a photosensitive material is such that the thickness of each material glass plate is slightly different,
Further, even in one glass plate, there is a partial thickness variation and wavy bending. Also, when a flexible material such as a photographic film is applied as the photosensitive material, the table (4) does not always have a perfectly flat surface, so that the wavy curve is still generated. Exists. Therefore, when the light spot group is projected and imaged by the reduction optical system described above, a focus shift occurs due to a change in the surface height of the glass plate or the photographic film, which causes a problem such as a decrease in sharpness of a recorded image. Cause.

In order to eliminate this inconvenience, the eighth apparatus shown in the figure automatically adjusts the position of the reduction optical system in the optical axis direction in response to changes in the surface height of the glass plate to keep the light spot group sharp. It forms an image.

On the surface of the seat plate (60) installed vertically in the exposure head,
The lift plate (61) is mounted so as to be vertically slidable by a pair of left and right guides (62) (63). A reduction optical system (64) is attached to the center of the front surface of the lift plate (61), and a light source (37), a lens (39a), and a mirror (3) that constitute an automatic focusing device.
8), lens (39b), mirror (40) and photoelectric element (41)
Has been placed. Further, springs (67) are respectively installed on the support shafts (65) standing upright on the left and right edges of the lift plate (61) and the corresponding support shafts (66) standing upright on the seat plate (60). The lifting plate (61) and the weight of each component attached thereto are supported, and the backlash of the drive unit is removed to ensure a smooth and highly accurate lifting state.

A nut (68) protruding leftward is attached to the upper part of the lifting plate (61), and a vertical screw shaft (69) is screwed therein. The screw shaft (69) is a pair of upper and lower bearings (7
0) (71) is supported, and the DC motor (72) installed above drives it through the speed reducer (73) to elevate and lower the lift plate (61), and reduce it mounted on the lift plate (61). Focusing is performed so that the exposure light beam group projected from the optical system (64) forms a sharp image on the exposed area (S) of the lower glass dry plate (6).

This focus adjustment is operated as follows by the automatic focus adjustment device installed on the lift plate (61).

From the light source (37), a light beam with a small amount of light that does not expose the glass plate to light is emitted, and is reflected by the mirror (38) via the lens (39a) to cover the glass plate (6). The light is incident on the exposure area (S) from an oblique direction, and the reflected light is passed through the lens (39b) and the mirror (40).
An image is formed on the photoelectric element (41). The photoelectric element (41) is the ninth
As shown, depending on the position of the incident point (C) of the light beam,
Two kinds of current values (I _A ) and (I _B ) proportional to the distances “A” and “B” from both ends of the element to the incident point (C) are output.

That is, when the lift plate (61) moves in the vertical direction and the distance to the glass dry plate (6) changes, the projection point of the light beam from the mirror (38) moves, and the photoelectric element (41) accordingly. Since the position of the incident point (C) with respect to X moves in the X-axis direction, the distances "A" and "B" change, and the output current values (I _A ) (I _B ) change. Therefore, when the elevating plate (61) is installed at a position where the exposure light beam group from the reduction optical system (64) sharply forms an image on the surface of the glass dry plate (6), the photoelectric element (41) is The positions of the light beams are adjusted so that the two current values (I _A ) and (I _B ) are equal, that is, the light beams are incident on the center of the photoelectric element (41). The DC motor (72) which is fixedly arranged and drives the lift plate (61) is feedback-controlled by two current values (I _A ) and (I _B ) to perform automatic focus adjustment.

FIG. 10 is a block diagram showing one embodiment of the feedback control circuit for automatic focus adjustment.

The output of the photoelectric device (41) (I _A) and (I _B), respectively the current - voltage converter (74A) and the voltage value by (74B) (V _A)
And (V _B ) and input to the addition circuit (75) and the subtraction circuit (76) to calculate the values of “V _A + V _B ” and “V _A −V _B ”. These values are input to the division circuit (77), The value of is calculated.

This value is passed through the amplifier (78) to the DC motor driver (7
9) to control the drive of the DC motor (72).

When the position of the lift plate (61) is low and the irradiation distance of the exposure scanning light beam is shorter than the required value, the incident point (C) of the light beam on the photoelectric element (41) via the lens (39). Is the ninth
Since it is deviated to the left in FIGS.
The output of the division circuit (77) is positive and the DC motor (7
2) rotate the elevator plate (61) in the forward direction to raise the elevator plate (61) to “A = B” at the required irradiation distance, and the output of the division circuit (77) becomes “0”. 77) stops. On the contrary, when the position of the lift plate (61) is high and the irradiation distance is long, the incident point (C) of the light beam is deviated to the right and A <B.
When the output of the division circuit (77) becomes a negative value, the DC motor (72) is negatively rotated to lower the lift plate (61) and stop at the height of the required irradiation distance. Reference numeral (80) is a tacho-generator that feeds back the rotation speed of the DC motor (77) to the driver (79) in conjunction with the driving of the DC motor (72).

During the exposure scan, activate the autofocus device described above,
By maintaining the irradiation distance of the exposure scanning light beam at a constant required value, a glass dry plate (6) which is a photosensitive material
It is possible to correct an error in the surface height of the above and secure a sharp image formation state on the entire surface.

In the case of a glass plate, the automatic focusing means using the light beam reflected on the surface to be exposed has a disadvantage that it is affected by a light beam reflected on the back surface of the glass plate and malfunctions. That is, as shown in FIG. 12, in addition to the light beam projected on the glass plate (6) being reflected on the front surface shown by the solid line, a part of the light beam enters the glass plate and is reflected on the back surface. Inner surface reflection is repeated, a plurality of light beams indicated by chain lines are emitted, and the plurality of light beams are incident on the photoelectric element for position detection in parallel, which causes an inconvenience in position detection.

The automatic focus adjusting device applied to the device of the present invention is designed to eliminate the above inconvenience, and will be described with reference to FIG.

The light beam projected on the glass dry plate (6) passes through two types of optical paths to the light receiving side, namely a front surface reflected beam shown by a solid line and a back surface reflected beam shown by a chain line reflected by the back surface of the glass dry plate (6). reflect.

When the distance between the reduction optical system (64) and the surface of the glass dry plate (6) is an irradiation distance at which the required sharp image can be obtained, the optical axis of the lens (39b) is placed in the optical path through which the surface reflected beam passes. The positions of the respective members are set so that the light beam which is aligned with and which is reflected by the mirror (40) is incident on the center of the photoelectric element (41).

At this time, the back-reflected beam indicated by the chain line is the lens (39b).
It is set so that the light enters the peripheral part of the mirror (40) and converges toward the optical axis and then enters the mirror (40), and the reflected optical path faces the outside of the effective area of the photoelectric element (41). That is, based on parameters such as the incident angle (θ) of the light beam on the glass plate surface, the thickness (t) of the glass plate, and the refractive index, the size of the photoelectric element (41) in the X-axis direction and the lens (39a) ( By selecting the focal length of 39b) and configuring the back surface reflected beam so that it does not enter the photoelectric element (41), only the front surface reflected beam shown by the solid line is detected, and accurate automatic focus adjustment is performed. is there.

Further, in a field where the photoelectric element (41) has a large dimension in the X-axis direction and the back surface reflected beam is incident on the photoelectric element (41), a slit plate (41
It is desirable to install S) so that only the surface reflected beam is incident.

Next, FIG. 13 is a block diagram showing a control means for performing the functions of the above-described exposure drawing apparatus.

The image pattern data stored in the disk (81) and the magnetic tape (MT) (82) is read out via the host computer (83), and the raster image processor (RIP) (8
Send to 5) and convert to XY raster pattern data. An image of the target area is displayed on the CRT monitor (84) according to the image pattern data of the desired area as necessary for confirmation.

The image data converted into a raster pattern is sent to the AOM driver (87) via the interface (I / F) (86) and built into the exposure head (20 ').
The AOM (28A) (28B) is controlled to control the modulation of each light beam.

The I / F (86) also outputs control signals to the sequence controller (88) and the servo controller (89).

On the other hand, with the movement of the table (4) in the Y-axis direction,
The fine pitch pulse signal output from the linear encoder (8) is appropriately divided as necessary to obtain a clock pulse signal having a frequency corresponding to the raster pitch of the image data, and the pixel corresponding to the position of the table (4) is obtained. Read the data of and control AOM (28A) (28B).

At the same time, the coarse pitch pulse signal output from the linear encoder (9) is input to the servo controller (89) to control the linear motor (7) that drives the table (4) in the Y-axis direction.

In this way, the reason for using two types of pulse signals with different pitches is that if a high-frequency pulse signal for image data control is also applied to drive control of a linear motor, drive is performed by limiting the control frequency. Slowing down,
If the image data is controlled by a pulse signal with a relatively low frequency for linear motor control that drives the table at an appropriate speed, the pixel size becomes too large and high precision is achieved. This is because it is not possible to record a duplicate image of.

Thus, while driving the table (4) in the Y-axis direction,
AOM (28A) based on raster pattern image data
Modulation control is performed so that each light beam passing through (28B) is individually turned on and off, and a glass dry plate which is a photosensitive material (6)
The sample is scanned and exposed to record a duplicate image. If 20 sets of light beams are adjusted and controlled by two sets of AOMs, an image of 40 scanning lines is exposed and recorded by one stroke (one scanning cycle) of the table (4).

At this time, since the light spot groups for exposure are arranged in two rows with a distance in the Y-axis direction, the exposure timings of the light sbot groups on the leading side and the trailing side are shifted. To correct this shift, turn on the light beam group corresponding to the light spot group on the subsequent side of the two AOMs (28A) and (28B).
The FF-controlled image data signal is input after a required time delay from the image data signal on the preceding side. This delay amount is controlled by adjusting the position of the triangular prism (31) in the optical system so that the distance (l) between the light spot groups focused on the exposure surface is an integer multiple of the unit pixel size. If it is set so that the required number (integer) of the image data in the main scanning direction is counted and the control signal for the light spot group on the subsequent side is collectively delayed, the timing adjustment control is performed. Is easy. Further, in the case of the device of the present invention, this timing adjustment may be performed for each light beam group, and is not for each individual light beam, so control is extremely easy.

When the exposure recording for one stroke of the table (4) is completed, the X-axis motor (17) is activated by the command of the sequence controller (88) to expose the exposure head (20 ') in the X-axis direction for exposure. The distance corresponding to the row width of the light spot group is moved. The amount of movement of the exposure head (20 ') is detected by the linear encoder (21) on the X-axis side.

Then, the linear motor (7) in the Y-axis direction is activated again, the table (4) is driven, the exposure scanning is performed on the adjacent region of the glass dry plate (6), and this is repeated sequentially,
The entire surface of the desired image pattern is recorded. After moving the exposure head (20 ') in the X-axis direction by a required distance, if there is no image data in the exposure area for one stroke of the next table (4), drive the table (4). Instead, the exposure head (20 ') is controlled to move to the next exposure area to reduce the total drawing time.

Before operating the automatic focus adjustment device, raise the position of the lift plate (61) to a standby position higher than the focus position of the light beam and lower it before starting drawing. It is desirable to control so as to stop at the focal position.
In focusing with a normal microscope, in order to avoid the objective lens from coming into contact with the object to be inspected (preparation) and damaging it, in reverse to this method, first lower the lens barrel to bring the objective lens closer to the preparation. Although the focus state is obtained while raising, the light beam reflected by the back surface of the glass plate is earlier than the surface reflection beam when such a method is used in the drawing apparatus of the present invention. This is because it becomes inconvenient for the required focus adjustment.

As described above in detail, in the drawing exposure apparatus of the present invention, the scanning exposure is performed by the optical spot row, in the drawing exposure apparatus, a plurality of groups of optical spot rows perpendicular to the main scanning direction are moved back and forth in the scanning direction, and By arranging the relative phases of the light spot rows of each group so as to be sequentially shifted in the sub-scanning direction, the scanning line pitch can be made substantially dense, and a duplicate image can be recorded at high speed and high speed. .

Although the above description is based on the illustrated embodiment,
The present invention is not limited to the above contents and includes various application modifications.

For example, in the above-mentioned embodiment, the light beam emitted from one light source is branched by the beam splitter and is made incident on a plurality of sets of beam expanders and AOMs. Light beams that are emitted separately may be applied.

Further, in the above embodiment, the case where the two groups of light beams are modulated by the two sets of AOMs and the light beams are arranged in a required positional relationship by the combining optical system has been described. The number of light spot rows projected on the recording medium is not limited to two, and if necessary, three or more groups of light beams may be applied to further increase the recording scan line density to achieve higher quality. It is also possible to record a duplicate image of the. In that case, while increasing the required number of AOMs and the like, an optical system for combining the light beam groups shown in FIG.
It suffices to add the required number of stages and perform sequential synthesis.

In the above description, the case where a glass dry plate having high dimensional stability is applied as the photosensitive material is mainly described, but it goes without saying that the device of the present invention can apply the above-mentioned photographic film in addition to the glass dry plate. It is also possible to draw on a photosensitive material obtained by coating a photoresist on a metal plate or a printed wiring board, and the invention is not limited to a glass dry plate.

Further, in the above-mentioned embodiment, the table (4) and the exposure head (20 ') are supported on the guide rail via the air bearing, but it goes without saying that a normal bearing may be used.

〔The invention's effect〕

(1) Since the line-sequential scanning exposure is performed by a plurality of light beams arranged in parallel, high-speed writing is possible as compared with the vector type drawing apparatus.

(2) By arranging a plurality of groups of scanning light spot rows with their phases shifted in the direction intersecting the scanning lines, the scanning line pitch can be made substantially high and a highly accurate duplicate image can be recorded. it can.

(3) The correction of the deviation of the scanning time between the light spot rows on the leading side and the trailing side can be easily controlled because the trailing side can be collectively delayed.

(4) Since an automatic focusing device is attached, the scanning light spot can always be sharply focused even if the surface of the photosensitive material such as the glass plate has irregularities such as waviness. It is possible to record a duplicate image of.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an apparatus according to one embodiment of the present invention,
2 is a perspective view showing the arrangement of the optical system of the apparatus, FIG. 3 is a perspective view showing the optical system for combining the light beam groups, and FIG.
FIG. 5 is a diagram schematically showing the positional relationship of the light beams of the group, FIG. 5 is a schematic diagram showing a light spot array for scanning exposure, and FIG. 6 is a schematic diagram showing the state of an image recorded by the apparatus of the present invention. 7th
FIG. 8 is a schematic view showing a state of an image recorded with only one light spot row, and FIG. 8 is an elevation view of an automatic focus adjustment device.
FIG. 10 is a schematic diagram showing a photoelectric element of an automatic focusing device, FIG. 10 is a block diagram of an automatic focusing control circuit, FIG. 11 is a schematic diagram showing an optical path of the automatic focusing device in the present invention, and FIG. 12 is a glass plate. FIG. 13 is a schematic diagram showing a back surface reflection optical path in FIG. 13, and FIG. 13 is a block diagram showing a control means of the first illustrated device. (1) …… frame, (2) …… base plate, (3) …… guide rail, (4) …… table, (5) …… vacuum suction hole, (6) …… photosensitive material (glass dry plate) (7) …… Linear motor / coil (8) (9) …… Linear scale for encoder, (10) …… Photoelectric sensor, (11) (12) …… Abutment, (13) (14) …… Guide Rail, (15) …… Screw shaft, (17) …… Servo motor, (18) …… Sliding base, (19) …… Light source, (20) …… Optical system, (20 ′) …… Exposure head, (21) …… linear scale, (22) …… laser light source, (25) …… beam splitter, (27A) (27B) …… beam expander, (28A) (28B) …… multi-channel Type AOM, (29A) (29B) …… Aperture plate, (30A) (30B) …… Mirror, (31) …… Triangular prism mirror, (32) …… Mirror, (33) 34) …… Lens, (35) …… Zoom lens, (36) …… Exposure light point group, (37) …… Light source, (38) (40) …… Mirror, (39) …… Lens, ( 41) …… Photoelectric element (41S) …… Slit plate, (44) …… Slide base, (45) …… Base, (46) …… Spring, (48) …… Screw shaft, (52) …… Light spot, (60) …… seat plate, (61) …… elevating plate, (62) (63) …… guide, (64) …… reduction optical system, (67) …… spring, (68) …… Nut, (69) …… screw shaft, (72) …… DC motor, (80) …… tacho generator.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04N 1/107 1/23 103 Z 9186-5C (72) Inventor Yasuyuki Wada Horikawa Duji, Kamigyo-ku, Kyoto-shi, Kyoto Prefecture Nouchi Uru 4-chome Tenjin Kitamachi No. 1 No. 1 Dainippon Screen Mfg. Co., Ltd. (72) Inventor Eiichi Tamaki No. 1 No. 1 Tenjin Kitacho, Horikawa Touji, Kamigyo-ku, Kyoto, Kyoto Prefecture Screen Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A table, which is slidably supported by a guide rail in the main scanning direction, holds a photosensitive material on its upper surface, and a plurality of light beams arranged in a linear array. The positions of the light beams in the sub-scanning direction are sequentially shifted by P / N (where P is the pitch of the light beams and N is the number of light beam groups) for each light beam group at intervals. A guide in a sub-scanning direction that is perpendicular to the moving direction of the table and has a built-in exposure optical system that projects and forms an image as a light spot group on the surface of the photosensitive material held on the table by the plurality of arranged light beam groups. An exposure head slidably supported on a rail, and an automatic focus adjustment for adjusting the position of the exposure optical system in the optical axis direction by detecting a change in the position of the surface of the photosensitive material attached to the exposure head. Means for the table and the exposure head With the move,
A drawing exposure apparatus comprising position detection means for detecting those positions and control means for controlling the light beam modulation means based on an image to be recorded corresponding to the positions of the table and the exposure head.