JPH08310194A - Multi-beam image forming recorder - Google Patents

Abstract

PURPOSE: To provide a multi-beam image forming recorder capable of recording an accurate and precise image at a high speed without deflecting the beam by a mechanical mechanism. CONSTITUTION: The multi-beam image forming recorder comprises a plurality of LEDs 42 mounted in predetermined two dimensional pattern on a board, an aperture plate 43 formed with a plurality of apertures corresponding 1:1 to the plurality of LES2, a contraction optical system for focusing the lights emitted from the plurality of LEDs and passed through the plurality of apertures and a holding member 46 for so holding while restricting the directions of the plurality of LEDs that the beams emitted from the plurality of LEDs are directed to the apertures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam drawing / recording method for drawing a precise image, for example, a circuit pattern on a mask for exposure printing for making a printed circuit board, using a plurality of beams. Regarding the device.

[0002]

[Prior art]

As a plotter for drawing a precise image, a laser plotter for drawing a two-dimensional image by using a laser beam as a light source and performing a main scan by a deflection scanning optical system while moving an image forming surface and sub-scanning. Has been known for a long time. However, the laser plotter performs deflection scanning using a mirror that rotates or oscillates at a high speed, and it is difficult to achieve high accuracy, and it takes a high cost to increase the accuracy. Further, when a semiconductor laser is used as a light source, there are problems that a large amount of heat is generated and astigmatism occurs and an optical component needs to be added to correct it. In addition, a drive circuit for accurately modulating the laser beam that scans the image plane at high speed was also required.

[0004]

In view of the above circumstances, the present invention provides a multi-beam system capable of recording a high-precision and high-definition image at high speed without deflecting the beam by a mechanical mechanism. The purpose is to provide a drawing / recording device.

[0005]

Therefore, the multi-beam drawing / recording apparatus of the present invention has a plurality of LEDs mounted on a substrate in a two-dimensional predetermined pattern and the plurality of LEs.
An aperture plate in which a plurality of openings corresponding to D in a one-to-one correspondence are formed in the predetermined pattern; a reduction optical system that forms an image of light emitted from the plurality of LEDs and transmitted through the plurality of openings; A holding member is provided between the substrate and the aperture plate, and holds the beams while restricting the directions of the LEDs so that the beams emitted from the LEDs are directed toward the opening. In addition, the holding member has a function as a light blocking member that prevents a beam emitted from each of the plurality of LEDs from entering an opening other than one of the plurality of openings corresponding to the LED. It is possible. Further, it is preferable to use a material having low thermal expansion as the holding member.

FIG. 1 is a perspective view showing the external appearance of a multi-beam drawing / recording apparatus 100 of this embodiment. The drawing / recording apparatus 100 of the present embodiment is an apparatus for drawing a circuit pattern on a mask for exposure printing for making a printed circuit board. Multi-beam drawing / recording device 100
The apparatus body base 1 is provided with a photosensitive material mounting table 2 for mounting a photosensitive film 3 on which a circuit pattern is formed. The table 2 can be reciprocated in the Y direction in the figure by rotating the ball screw 2B by a table driving motor (not shown) with the lower surface thereof guided along a pair of rails 2R extending in the Y direction. ing.

The drawing light beam is emitted from the light irradiation unit 4 as a plurality of beams which are two-dimensionally arranged in a predetermined area. The light irradiation unit 4 is an optical system mounting stage 5S.
It is fixed to the optical base 5 placed on the. The optical base 5 is movable in the X direction by being guided by a pair of guide rails 5R extending in the X direction. The optical system drive motor 5M rotates the ball screw 5B to move the light irradiation unit 4 in the X direction. Be moved to. The light irradiation unit 4 includes a scale detection head 5 for detecting the position detection linear scale 5K provided on the apparatus main body base 1.
D is provided, and the optical system drive motor 5M is feedback-controlled based on the detection signal of the scale detection head 5D. Although not shown, the photosensitive material mounting table 2 is provided with a table position detecting head for detecting a table position detecting scale (not shown),
The table driving motor is feedback-controlled based on the output signal of the table position detecting head.

FIG. 2 is a side view showing the outline of the structure of the light irradiation unit 4. The light irradiation unit 4 includes a plurality of LEDs (light emitting diodes) 42 mounted on a printed circuit board 41 in the unit, an aperture panel 43 having apertures corresponding to the LEDs 42 in a one-to-one correspondence, and a beam transmitted through the aperture. First lens group 44 and second lens group 4 for forming an image on the surface of the photosensitive film 3
5 has a reduction optical system. In this embodiment, as the photosensitive film 3, a so-called ortho-type photosensitive material having a spectral sensitivity at a wavelength of 400 nm to 570 nm is used. The LED 42 has a peak wavelength of 450n.
The so-called blue LED of m is used.

FIG. 3 is a view of the aperture panel 43 seen from the upper surface side of the light irradiation unit 4 for explaining the arrangement of the apertures formed in the LED 42 and the aperture panel 43. The position of the LED 42 is indicated by a broken line. Further, FIG. 4 shows a pattern of point images formed on the photosensitive film 3. In the present embodiment, the images of 1/25 times are projected on the photosensitive film 3 by the lenses 44 and 45 of the first and second groups.

An apparatus for drawing a circuit pattern on a printed circuit board is required to have precise drawing performance, and therefore high resolution is required. However, when the LED is used as the light source, the physical size of the LED itself limits the density of the light source arrangement. The LED used in the drawing / recording apparatus of this embodiment has a maximum diameter of 3.8 mm on a plane parallel to the printed board 41. In order to arrange these so as not to contact each other, as shown in FIGS. 3 and 4, the beam is emitted from the apertures arranged discretely to form discrete point images on the surface of the photosensitive film 3.
Further, in order to increase the size of the point image projected on the photosensitive film 3 and the accuracy of the position, the aperture panel 43 is provided with
An aperture corresponding to the LED 42 is formed, and an image of the aperture panel 43 is projected on the photosensitive film 3.

In this embodiment, table movement and L
By controlling the light emission timing of the ED 42, when a certain line (a line along the X direction) is focused,
As shown in FIG. 5, the images of all the beams are arranged in a line in a state of being close to each other.

In the drawing / recording apparatus 100 of this embodiment, 2048 LEDs 42 are arranged two-dimensionally. As shown in FIG. 3, 32 LEDs 42 are arranged in the Y direction.
Are arranged (hereinafter, the LEDs 42 arranged in the Y direction are referred to as Y-row LEDs 42). Similarly, 64 rows of the LEDs 42 arranged in the Y direction are arranged in the X direction. Focusing on one line in the X direction, the 64 LEDs 42 are arranged in a straight line along the X direction (hereinafter, the LEDs aligned in the X direction are referred to as X rows of LEDs). LED in row Y
Are arranged at positions sequentially shifted by the diameter of the aperture AP, as shown by Y1 to Y32 in FIG. 3, and the aperture AP is also formed in the same arrangement. Aperture AP
The diameter of LED is LEDY1 at the beginning of the Y row and LE at the beginning of the adjacent row.
The distance from the DY33 in the X direction is set equal to the value obtained by dividing the distance in the X direction by the number of LEDs in the Y column. That is, 32 in the Y column
LEDs are arranged, and the distance between Y1 and Y33 is
It is 4 mm. Therefore, the diameter of the aperture AP is 0.125
It is mm.

Now, consider a case where the beam is emitted from the light emitting unit 4 while moving the table 2 in the Y direction. Attention is paid to the image formed on the photosensitive film 3 by the beams emitted from the LEDs of the row including the LEDY1.
The beams emitted from Y1, Y33, Y65, ... Form point images discretely arranged in a line on the photosensitive film 3 (the row in which the point images are arranged is shown as a line L1 in FIG. 4). Next, when the table is moved and the line L1 reaches the position corresponding to the beam position emitted from the LEDs of the row including Y2, Y2 is adjacent to the discrete point image previously formed on the line L1, An image corresponding to Y34, ... Is formed. In the same manner, subsequently, adjacent images are sequentially formed on the same line, and finally the LED Y32 of the row including Y32,
When the point images corresponding to Y64, ... Are formed on the same line L1, as a result, as shown in FIG.
Eight point images are formed adjacently on the same line. Therefore, when the table 2 (and therefore the photosensitive film 3) is moved by the pitch in the Y direction of the images that are discretely arranged two-dimensionally, exposure is performed to sequentially form point images on each line on the photosensitive film 3. After being interpolated, each line is finally composed of 2048 dots.

Drawing on the photosensitive film 3 is performed as follows. First, while moving the table 2 in the Y direction, the above-described image forming process is performed to form an image on the surface of the photosensitive film 3 in a strip shape extending in the Y direction. When an image is formed up to the edge of the photosensitive film 3, the optical system mounting stage 5S is moved to the X position.
Move in the direction. After moving the optical system mounting stage 5S, the table 2 is moved in the opposite direction to the previous time, and in the same manner, a belt-shaped image extending in the Y direction is formed on the photosensitive film 3. In addition, the optical system mounting stage 5S does not overlap adjacent band-shaped images, and
It is moved in the X direction exactly by a predetermined length determined by the arrangement of the LEDs so as to prevent a blank portion in which an image is not formed from entering.

FIG. 6 is a drawing / recording apparatus 100 of this embodiment.
3 is a block diagram illustrating a control system for performing the drawing process of FIG. The drawing data is stored in the memory 13 as a bit map, and is synchronized with a predetermined clock signal so that the LED
Data corresponding to the arrangement of the LEDs 42 of the array 42A is input to the LED drive circuit 12, and the LED drive circuit 1
Reference numeral 2 drives each LED 42 by a pulsed electric current having a predetermined intensity corresponding to an input signal to emit light. The table 2 and the optical base 5 are driven together with the driving of the LED array 42A.
Is also controlled by the CPU 10. In the image drawing / recording apparatus 100 of this embodiment, the CPU 10 drives the optical system drive motor 5M to position the light irradiation unit 4 mounted on the optical base 5 in the X direction, and then the table moving motor 2M. The LED array 42A is caused to emit light while being driven to move the table 2 in the Y direction. While the optical system driving motor 5M and the table moving motor 2M are being driven, the outputs of the scale detection heads 5D and 2D are input to the CPU 10, and the optical system driving motor 5M and the table moving motor 2M are feedback controlled. There is.

In the drawing / recording apparatus 100 of this embodiment, the LEDs 42 are arranged in a predetermined pattern shown in FIG. 3, and the aperture plate 43 has apertures formed in the same pattern. As shown in FIG. 3, the size of the aperture is considerably smaller than the size of the LED 42. Further, the LED 42 of this embodiment has a structure in which the tip portion is covered with a lens in order to obtain strong light by giving directivity. Therefore, the LED 42 exhibits a directional characteristic as shown in FIG. LED 41 substrate 41
Since the lead wire of the LED 42 is soldered to the substrate during assembly, the lead wire is twisted when the lead wires are not uniform in length and the direction of the beam is accurately directed toward the aperture. In some cases, it may not happen. Further, since a large number of LEDs 42 are arranged at high density, even if each of the LEDs 42 has high directivity, light leaked to an aperture other than the corresponding aperture may affect the photosensitive surface. .

For this reason, in this embodiment, as shown in FIG. 8, the LE LE is provided between the aperture plate 43 and the substrate 41.
An LED holder 46 for holding D42 is provided. Since the LED 42 with lens has a cylindrical shape having a dome-shaped tip portion, a plate-shaped member having an opening having a size into which the tip portion and the cylindrical portion can be inserted is used as the LED holder 46. The opening into which the LED 42 is inserted is formed in the same pattern as the LED arrangement pattern. When the LED holder expands due to heat generated by driving the LED 42, the LED 42 and the LED
The LED holder 46 is preferably made of a material having a small coefficient of thermal expansion because the positional relationship with the opening for holding may be misaligned and the direction of the beam may be misaligned. In this embodiment, the LED
Ceramic is used as the holder 46. Also, LE
By making the thickness of the D holder 46 larger than the length of the tip of the LED 42, the LED holder 46 can have a light blocking function. The LED holder 46 is fixed to the substrate 41 via a spacer. In addition, the LED holder 4
6 between the aperture plate 43 and the aperture plate 6 having a light-shielding property
By installing 7, LED while improving the light blocking effect
It is possible to prevent mutual damage between the holder and the aperture plate 43. As the aperture plate 43, a photomask in which a mask surface having a light shielding pattern is formed on one surface of a transparent member can be used.

[0018]

Since a plurality of LEDs are used as the light source,
Output control and lighting control can be performed at high speed. Also,
Since the plurality of LEDs are surely held by the LED holder so that the beam is directed toward the aperture, the LEDs can be easily attached to the substrate, and the position of the image forming pattern can be precisely adjusted. Furthermore, since the LED array is used as a light source, it is not necessary to use a mechanical deflecting means, and thus it is possible to perform image formation with high accuracy.

[Brief description of drawings]

FIG. 1 is a multi-beam drawing / recording apparatus 10 of the present embodiment.
It is a perspective view which shows the external appearance of 0.

FIG. 2 is a side view showing a schematic configuration of a light irradiation unit 4.

FIG. 3 is a view of an aperture panel 43 seen from the upper surface side of a light irradiation unit 4.

FIG. 4 is a diagram showing a pattern of a point image formed on a photosensitive film 3.

FIG. 5 is a diagram showing a state where all the point images are arranged in a line in a state of being close to each other.

FIG. 6 is a block diagram of a control system for performing a drawing process.

FIG. 7 is a graph showing directional characteristics of an LED with a lens.

FIG. 8 is an LED, which is a characteristic configuration of the present embodiment.
It is a figure explaining a holder.

[Explanation of symbols]

 1 Drawing / Recording Device Main Body 2 Photosensitive Material Mounting Table 2B Ball Screw 2R Guide Rail 2M Table Driving Motor 2D Scale Detection Head 3 Photosensitive Film 4 Light Irradiation Unit 5 Optical Base 5S Optical System Mounting Stage 5B Ball Screw 5R Guide Rail 5D Scale Detection head 5K Linear scale for position detection 42 LED 43 Aperture plate 46 LED holder 47 Buffer member

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Koichi Maruyama 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Kogaku Kogyo Co., Ltd. (72) Tetsuya Nakamura 2-36-9 Maeno-cho, Itabashi-ku, Tokyo No. Asahi Kogaku Industry Co., Ltd.

Claims (7)

[Claims] 1. A plurality of light emitting diodes mounted on a substrate in a two-dimensional predetermined pattern, and an aperture plate having a plurality of openings corresponding to the plurality of light emitting diodes on a one-to-one basis in the predetermined pattern. , A reduction optical system that forms an image of light emitted from the plurality of light emitting diodes and respectively transmitted through the plurality of openings, and a beam emitted from the plurality of light emitting diodes provided between the substrate and the aperture plate. A multi-beam imaging / recording apparatus, comprising: a holding member that holds the plurality of light-emitting diodes while restricting their orientations toward the opening. 2. A plurality of light emitting diodes mounted on a substrate in a two-dimensional predetermined pattern, and an aperture plate having a plurality of openings corresponding to the plurality of light emitting diodes on a one-to-one basis in the predetermined pattern. A reduction optical system for focusing light emitted from the plurality of light emitting diodes and respectively transmitted through the plurality of openings, and provided between the substrate and the aperture plate, and the plurality of light emitting diodes are respectively inserted and inserted. A multi-beam drawing / recording apparatus comprising: a light emitting diode holding member having a plurality of openings formed in the predetermined pattern. 3. The peak wavelength of the plurality of light emitting diodes is
The multi-beam drawing / recording apparatus according to claim 1, wherein the multi-beam drawing / recording apparatus is between 400 nm and 550 nm. 4. The light emitting diode with a lens, wherein the plurality of light emitting diodes are light emitting diodes with a lens.
Or the multi-beam drawing / recording device described in 3. 5. The holding member serves as a light-shielding member that prevents a beam emitted from each of the plurality of light emitting diodes from entering an opening other than one of the plurality of openings corresponding to the light emitting diode. The multi-beam drawing / recording apparatus according to any one of claims 1 to 4, which functions. 6. The multi-beam drawing / recording apparatus according to claim 1, wherein the holding member is made of a material having a low thermal expansion coefficient. 7. A cushioning member is arranged between the holding member and the aperture plate.
6. The multi-beam drawing / recording device according to any one of 1 to 6.