JPH10297024A - Light source unit for multibeam plotting recorder and method for adjusting light beam emitting direction of led in light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a plurality of light emitting diodes two-dimensionally easily and accurately by arranging a plurality of hollow members of specified shape inserted with a plurality of light emitting diodes, a planar member having a plurality of openings to be fitted with the hollow members arranged specifically, and the like. SOLUTION: A light emitting diode LED 42 is selected after a tubular member 50 is bonded thereto and under a state where the positional relationship is determined between the LED 42 and the tubular member 50, the LED 42 is set in a specified jig and irradiated with light. The LED 42 is selected depending on the fact that the irradiating direction of a light peak part comes within a specified range. Since the tubular member 50 is bonded to the LED 42, the irradiating direction of a light peak part when the LED 42 is set in a jig through the tubular member 50 is identical to that when the LED 42 is fixed to an LED holder. More specifically, the irradiating direction of a light peak part has reproducibility because the tubular member 50 is bonded to the LED 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit of a multi-beam drawing / recording apparatus using a plurality of two-dimensionally arranged LEDs as light sources.

[0002]

2. Description of the Related Art Heretofore, there has been known a drawing recording apparatus for drawing a precise image using two-dimensionally arranged LEDs as a light source. Since such a drawing recording apparatus uses a plurality of LEDs as light sources, it is possible to control drawing dots, that is, to control output and lighting of each LED at high speed. In addition, it is known that drawing can be performed with high precision because no mechanical deflection means is used.

[0003]

In the above-described drawing recording apparatus, a recording material having photosensitivity is fixed in a planar state, and a plurality of beams emitted from a plurality of LEDs are transmitted through an imaging optical system. An image is formed by irradiating the exposed surface of the recording material. For this reason, it is necessary to make the incident intensity of the beams from the plurality of LEDs uniform on the surface to be exposed, and furthermore, to increase the light beam intensity on the surface to be exposed as much as possible to shorten the exposure time and to perform the printing. In order to increase the speed, it is necessary to align the emission direction of the light peak portion of the LED arranged in the light source unit with the image capturing direction of the optical system.

However, since the light emitting direction of the light peak portion of each LED has individual differences and has no correlation with the outer diameter shape of the LED, a light source unit having uniform characteristics among the LEDs is manufactured. Was a very time-consuming task. That is, even if an opening or the like for positioning the LED is provided in the light source unit, the light peak emission direction cannot be determined from the outer diameter shape of the LED. Therefore, it is necessary to produce a light source unit in which the directional characteristics of each LED are accurately aligned. Was difficult.

Further, as shown in FIG. 9, an LED is usually composed of a flange portion and a head portion, and a curved surface exists at the boundary between the two. Therefore, the upper edge of the LED mounting hole of the light source unit and this curved surface are connected. In the case of contact and fixation, the contact portion is in line contact, which causes a problem that the fixing strength of the LED to the light source unit is weakened.

In view of the above circumstances, an object of the present invention is to provide a light source unit of a multi-beam drawing / recording apparatus capable of two-dimensionally arranging a plurality of LEDs with a simple configuration and high accuracy.

[0007]

According to the present invention, a light source unit of a multi-beam drawing / recording apparatus according to the present invention comprises a plurality of LEDs and a plurality of LEDs having a predetermined outer shape through which the plurality of LEDs are inserted. It is characterized by having a hollow member and a plate member in which a plurality of openings into which the hollow member is fitted are formed in a predetermined arrangement. With this configuration,
A plurality of LEDs can be easily and accurately two-dimensionally arranged.

[0008] The plurality of hollow members may be respectively fixed to the plurality of LEDs. The plurality of openings formed in the plate member may be arranged in a matrix. Note that the present configuration can be applied to a case where a plurality of LEDs are not limited to be arranged in a matrix and are mounted with their light peak emission directions aligned.

[0009] The hollow member may be a cylindrical member. The LED includes a flange portion having a first predetermined diameter and a head having a second predetermined diameter smaller than the first predetermined diameter as a maximum diameter, and an outer diameter of the cylindrical member is the first diameter. By setting the third predetermined diameter larger than the second predetermined diameter, the LED can be positioned by reliably contacting the flange and the plate member.

[0010] By making the inner diameters of the plurality of openings substantially equal to the third predetermined diameter, the positioning accuracy of the LED can be improved.

Further, the height of the cylindrical member may be smaller than the thickness of the plate member. In this case, L
Since the tip of the ED and the surface of the plate member are almost coplanar,
An aperture plate having a plurality of apertures corresponding to the plurality of LEDs can be arranged near the plate member. Thereby, it is possible to adopt a configuration in which the beams emitted from the plurality of LEDs pass through the aperture formed in the aperture plate.

According to a ninth aspect of the present invention, in the method for selecting an LED of a light source unit of a multi-beam drawing / recording apparatus, the LED is mounted on a predetermined jig in a state where the LED is inserted through the cylindrical member. The emission direction of the beam emitted from the light source is measured, and only the emission direction of the beam within a predetermined range is used for the light source unit.

[0013]

FIG. 1 is a perspective view showing the appearance of a multi-beam writing / recording apparatus 100 according to an embodiment of the present invention. Multi-beam writing and recording apparatus 1 of the present embodiment
Reference numeral 00 denotes an apparatus for forming a circuit pattern for a printed circuit board on a mask for exposure printing used when the printed circuit board is formed.

In the multi-beam writing / recording apparatus 100, a photosensitive material mounting table 2 for mounting a photosensitive film 3 on which a circuit pattern is formed is provided on an apparatus main body base 1. The photosensitive material mounting table 2 is slidably supported along a pair of rails 2R whose lower surfaces extend in a direction indicated by an arrow Y in the figure. A ball screw 2B is arranged below the photosensitive material mounting table 2, and a nut (not shown) engaged with the ball screw 2B is fixed to a lower surface of the photosensitive material mounting table 2. When the ball screw 2B is rotated by a table driving motor (not shown), the photosensitive material mounting table 2 reciprocates in the Y direction in the figure while being guided by the rail 2R.

The drawing light flux is emitted from the light source unit 4 to a part of the exposure area of the photosensitive film 3 as a plurality of beams two-dimensionally arranged in a predetermined area. The light source unit 4 is fixed to the optical base 5 mounted on the optical system mounting stage 5S. The optical system mounting stage 5S is guided by a pair of guide rails 5R extending in the X direction and is movable in a direction indicated by an arrow X in the drawing. The light source unit 4 is moved in the X direction by rotating the ball screw 5B by the optical system drive motor 5M. The light source unit 4 includes a scale detection head 5D that detects the position detection linear scale 5K provided on the apparatus main body base 1.
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 (a position in the Y direction) detecting scale (not shown). Feedback control is performed based on the output signal of the table position detection head.

FIG. 2 is a diagram showing a schematic configuration of the light source unit 4. The light source unit 4 includes a plurality of LEDs (light emitting diodes) 42 mounted on a printed circuit board 41 in the unit, an LED holder 40 in which mounting holes 40H corresponding to the plurality of LEDs 42 are formed, and a plurality of LEDs 4.
An aperture panel 43 in which an aperture 43A is formed in one-to-one correspondence with a second lens group 44, and a first lens group 44 and a second lens group 45 for imaging a beam transmitted through the aperture 43A on the surface of the photosensitive film 3. It has a reduction optical system. The plurality of LEDs 42 are mounted in the mounting holes 40H of the LED holder 40, thereby defining the beam emission direction. At this time, the emission beam from each LED 42 passes through each aperture 43A of the aperture panel 43 and enters the first lens group 44 of the reduction optical system.

FIG. 3 is a view of the aperture panel 43 viewed from the upper surface side of the light source unit 4 for explaining the arrangement of the LEDs 42 and the arrangement of the apertures 43A formed on the aperture panel 43. Note that the position of the LED 42 is indicated by a broken line. FIG. 4 shows a pattern of a point image formed on the photosensitive film 3. In the present embodiment, 1/25 is set by the lenses 44 and 45 of the first and second groups.
A double image is projected on the photosensitive film 3.

An apparatus for forming a circuit pattern on a printed circuit board needs to have precise drawing performance, and therefore requires a high resolution. However, when an LED is used as a light source, the physical size of the LED itself limits the density of the light source arrangement. The LED used in the multi-beam writing / recording apparatus 100 of the present embodiment has a diameter of 3.8 mm on a plane parallel to the printed circuit board 41. In order to arrange them so as not to contact each other, as shown in FIGS.
And a discrete point image is formed on the surface of the photosensitive film 3. In addition, the aperture 43A is the photosensitive film 3
Is used to increase the accuracy of the size and position of the point image projected onto the image.

In the present embodiment, by controlling the timing of the movement of the table and the light emission of the LED 42, when attention is paid to a certain line (line along the X direction), as shown in FIG. The beam images are arranged in a row in a state of being close to each other.

In the multi-beam writing / recording apparatus 100 of the present embodiment, 2048 LEDs 42 are two-dimensionally arranged. As shown in FIG. 3, 32 LEDs 42 are arranged in the Y direction (hereinafter, the LEDs 42 arranged in the Y direction are referred to as LEDs Y in the Y row). 64 rows of the LEDs 42 arranged in the Y direction are arranged along the X direction. Focusing on one line along the X direction, 64 LEDs 42 are aligned in a line along the X direction (hereinafter, LEDs aligned in the X direction are referred to as LEDs in X rows). As shown by Y1 to Y32 in FIG. 3, the LEDs in the Y column are arranged at positions shifted sequentially in the X direction by the diameter of the aperture 43A, and the aperture 43A is also formed in a similar arrangement. The diameter of the aperture 43A is set equal to a value obtained by dividing the distance in the X direction between the first LEDY1 in the Y column and the first LEDY33 in the adjacent column by the number of LEDs in the Y column. That is, 32 LEDs are arranged in the Y column, the distance between Y1 and Y33 is 4 mm, and the aperture A
The diameter of P is 0.125 mm.

Here, a case is considered in which the beam is emitted from the light source unit 4 while moving the table 2 in the Y direction.
Focusing on the image formed on the photosensitive film 3 by the beam emitted from each LED in the row including the LED Y1, Y
Beams emitted from 1, Y33, Y65,... Form point images discretely arranged in a line on the photosensitive film 3 (rows in which the point images are arranged are shown as lines L1 in FIG. 4). Next, when the table moves and the line L1 reaches a position corresponding to the beam position emitted from the LED in the row including Y2, Y2, Y2, An image corresponding to Y34,... Is formed. Subsequently, similarly, adjacent images are sequentially formed on the same line, and finally, the LED Y in the row including Y32
32, Y64,... Correspond to the same line L1
When formed on top, as a result, as shown in FIG.
2048 point images are formed on the same line adjacent to each other along the X direction. Therefore, by exposing when the table 2 (and thus the photosensitive film 3) has moved by the pitch in the Y direction of the images arranged discretely two-dimensionally, a point image is sequentially formed on each line on the photosensitive film 3. Interpolated, and finally each line (X direction) is 2
It consists of 048 dots.

The drawing on the entire photosensitive film 3 is performed as follows. First, the above-described image forming process is performed while moving the table 2 in the Y direction, and an image is formed on the surface of the photosensitive film 3 in a belt shape extending in the Y direction. When the image is formed up to the end of the photosensitive film 3, the optical system mounting stage 5S
Is moved in the X direction. After moving the optical system mounting stage 5S, the table 2 is moved in the direction opposite to the previous direction (the opposite direction in the Y direction), thereby similarly forming a belt-shaped image extending in the Y direction on the photosensitive film 3. The optical system mounting stage 5S is provided for a predetermined length determined by the arrangement of the LEDs so that adjacent strip-shaped images do not overlap and there is no blank portion where no image is formed. Moved exactly in the X direction.

FIG. 6 is a view showing a state in which the LED 42 is mounted in the mounting hole 40H of the LED holder 40. The light emitting diode 42 has a head 422 and a flange 421. In the light emitting diode 42 used in the present embodiment, the flange portion 421 has a thickness of about 1 mm and a diameter of about 3.8
It has a cylindrical shape of mm. The head 422 is connected to the flange 4
The portion connected to 21 has a diameter of 3.2 mm, and the diameter decreases toward the tip (toward the lower side in FIG. 6), and the tip is formed substantially spherical.

Around the head 422, a cylindrical member 50 (see also FIGS. 7 and 8) is attached. That is, the head 42
2 is inserted into the cylindrical member 50 and the cylindrical member 50
It is attached to ED42. The cylindrical member 50 has an inner diameter of 3.0 m
m is a cylindrical metal processing member having an outer diameter of 3.2 mm, a thickness of about 0.1 mm, and a height (vertical length in FIG. 6) of less than 3.5 mm. The outer diameter is formed in consideration of a plus tolerance. The cylindrical member 50 is fixed to the head 422 by filling a gap between the head 422 of the LED 42 and the inner wall of the cylindrical member 50 with an adhesive. In a state where the cylindrical member 50 is fixed to the head 422, the tip (the lower end in FIG. 6)
It is located 3.5 mm from the flange 421.

The LED holder 40 has a thickness of 5.0 mm,
The mounting hole 40H has an inner diameter of 3.3 mm. The inner diameter is formed in consideration of a negative tolerance. Also, L
The thickness of the ED holder 40 is substantially equal to the height of the head 422 of the LED 42. As shown in FIG.
When the LED 42 to which the “0” is fixed is inserted into the mounting hole 40H, since the outer diameter of the cylindrical member 50 is larger than the maximum diameter of the head 422, the upper surface of the flange portion 421 (the lower surface in FIG. At least a part of the upper surface (the upper surface in FIG. 6).

That is, since the cylindrical member 50 is fixed to the head 422, the gradually increasing diameter portion near the flange 421 of the head 422 does not come into contact with the LED holder 40. At least a part of the upper surface of the flange portion 421 and the upper surface of the LED holder 40 are positioned in contact with each other. If head 422
When the portion where the diameter changes is in contact with the edge of the mounting hole 40H, the LED 42 may be mounted on the LED holder 40 in a state where the emission direction of the light peak portion is inclined in a direction unrelated to the image capturing direction of the optical system. However, according to the configuration of the present embodiment, since the posture of the LED 42 with respect to the LED holder 40 is defined by the relationship between the surfaces of the flange portion 421 and the LED holder 40, the LED 42 is inclined in an unnecessary direction. Is not attached to the LED holder 40. Further, since the flange portion 421 and the LED holder 40 are in surface contact, the fixing strength of the LED 42 is increased.
Further, the dimensions of the head and the shape of the boundary curved surface between the flange and the head may be different depending on the LED used for the LED 42, but the flange 421 and the LED holder 40 are brought into surface contact according to these. It goes without saying that the dimensions such as the thickness of the cylindrical member 50 and the inner diameter of the mounting hole 40H may be determined.

The outer diameter of the cylindrical member 50 and the mounting hole 4
Due to the processing error of the inner diameter of 0H, LED42 is LED
Although there is a possibility that the cylindrical member 50 may shift in a direction parallel to the upper surface of the holder 42, as described above, the cylindrical member 50 has an outer diameter of 3.2 mm that allows for a plus tolerance, and the mounting hole 40H allows for a minus tolerance. Since the inner diameter is 3.3 mm, the range in which the cylindrical member 50 can move with respect to the mounting hole 40H is extremely small and can be substantially ignored. The cylindrical member 50 is fixed to the mounting hole 40H by an adhesive.

In the light source unit configured as described above, each LED 42 emits light in order to minimize unevenness in brightness of a drawn image and to efficiently use a beam emitted from each LED 42. It is desirable to match the direction of the light peak portion (the peak portion of the directivity characteristic) with the image capturing direction of the imaging optical system. For this purpose, it is necessary to select the LEDs 42 used for the light source unit. Next, a method of selecting the LEDs 42 will be described.

The selection of the LEDs 42 is performed after the cylindrical members 50 are fixed to the LEDs 42. That is, in a state where the positional relationship between the LED 42 and the cylindrical member 50 is determined, the LED 42 is set on a predetermined jig and irradiated with light. Depending on whether or not the irradiation direction of the light peak portion is within a predetermined range, the LED 4
Sort 2 out. Since the cylindrical member 50 is fixed to the LED 42, when the LED 42 is mounted on the jig via the cylindrical member 50, the emission direction of the light peak portion is determined by the LED.
The same direction is applied when the LED 42 is mounted on the LED holder 40. That is, since the cylindrical member 50 is fixed to the LED 42, reproducibility in the emission direction of the light peak portion is obtained.

According to the inspection using the jig, when the irradiation range of the light peak portion is within a predetermined range, the LED 42 is set to the LE.
When the LED 42 is mounted on the D holder 40 and a predetermined range is set so that the irradiation direction of the light peak portion matches the image capturing direction of the reduction optical system, after the LEDs 42 are selected using a jig, The LED 42 can be assembled simply by fitting the LED 42 into the mounting hole 40H of the LED holder 40, and the assembling work can be performed efficiently. Conventionally, when assembling the LEDs 42 to the LED holders, the assembling work was performed while adjusting the positions of the respective LEDs 42 on the LED holders 40, which was extremely inefficient. However, according to the light source unit of the present embodiment, the LEDs 42 can be easily selected, and the subsequent assembling work is simplified and made more efficient.

Also, the LED 42 having a predetermined inclination corresponds to the LED 42 having a specific light peak portion emission direction tendency.
Cylindrical member 5 with an inclined inner wall so that it can be fixed to
0 can also be used. In this case, the yield at the time of sorting can be increased. Further, after adjusting the positional relationship of the LED 42 with respect to the cylindrical member 50, a method of fixing the cylindrical member 50 to the LED 42 while maintaining the positional relationship may be adopted. That is, by adjusting the emission direction of the light peak portion of the LED 42 to coincide with the central axis of the cylindrical member 50 and then fixing the same so as to maintain the positional relationship, not only the above-described effect can be obtained, but also LED42
The need for sorting is eliminated.

[0033]

As described above, according to the light source unit of the multi-beam writing / recording apparatus of the present invention, the emission direction of the light peak from the LED and the image capture direction of the optical system can be matched with a simple configuration. Can be. At this time, LED
Is extremely easy to assemble to the light source unit, and the LED can be firmly fixed to the light source unit. In addition, according to the method of adjusting the light beam emitting direction of the LED of the light source unit of the multi-beam drawing / recording apparatus of the present invention, not only the selection of the LED is easy, but also the mounting of the selected LED to the light source unit is simplified. LED
The work efficiency of assembling is improved. Further, as described above,
When the cylindrical member is fixed to the LED by employing a method of fixing the LED so that the light peak emission direction of the LED coincides with the axis of the cylindrical member, it is not necessary to select the LED.

[Brief description of the drawings]

FIG. 1 shows a multi-beam writing / recording apparatus 10 according to an embodiment of the present invention.
FIG.

FIG. 2 is a side view schematically showing the configuration of the light source unit 4.

FIG. 3 is a view of the aperture panel 43 as viewed from the upper surface side of the light source unit 4.

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

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

FIG. 6 is an enlarged view of an LED, an LED holder, and a cylindrical member.

FIG. 7 is a top view of the cylindrical member.

FIG. 8 is a side view of the cylindrical member.

FIG. 9 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-beam drawing recording apparatus 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 source unit 5 Optical base 5S Optical system mounting stage 5B Ball screw 5R Guide rail 5D scale Detection head 5K Position detection linear scale 40 LED holder 40H LED mounting hole 41 Printed circuit board 42 LED 43 Aperture plate 44 First lens group 45 Second lens group 50 Cylindrical member 100 Multi-beam drawing / recording apparatus

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI // H04N 1/036

Claims (9)

[Claims] 1. A plurality of LEDs, a plurality of hollow members having a predetermined outer shape into which the plurality of LEDs are inserted, and a plurality of openings into which the hollow members are fitted are formed in a predetermined arrangement. A light source unit of a multi-beam writing and recording apparatus, comprising: 2. The light source unit according to claim 1, wherein the plurality of hollow members are fixed to the plurality of LEDs, respectively. 3. The light source unit according to claim 2, wherein the plurality of openings are arranged in a matrix. 4. The LED comprises a flange having a first predetermined diameter and a head having a second predetermined diameter smaller than the first predetermined diameter as a maximum diameter, wherein the hollow member is provided. 4. The light source unit according to claim 3, wherein an inner diameter of the light source is larger than the second predetermined diameter. 5. The hollow member according to claim 4, wherein the hollow member is a cylindrical member, and the inner diameter of the cylindrical member is a third predetermined diameter larger than the second predetermined diameter. Light source unit for multi-beam lithography recorder. 6. The light source unit according to claim 5, wherein an inner diameter of the plurality of openings is substantially equal to the third predetermined diameter. 7. The light source unit according to claim 6, wherein the height of the cylindrical member is smaller than the thickness of the plate member. 8. An aperture plate formed with a plurality of apertures corresponding to the plurality of LEDs is disposed near the plate member, and a beam emitted from the plurality of LEDs passes through an aperture formed on the aperture plate. The light source unit of the multi-beam writing / recording apparatus according to claim 7, wherein 9. An LED is mounted on a predetermined jig in a state where the LED is inserted through the cylindrical member, and an emission direction of a beam emitted from the LED is measured. The method for adjusting a light beam emitting direction of an LED of a light source unit of a multi-beam writing / recording apparatus according to claim 5, wherein only the light within the range is used for the light source unit.