JP2004181478A - Multi-beam multi-head plotting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-beam multi-head plotting device capable of easily performing image coupling between plotting heads highly precisely, and shortening a plotting period of time. <P>SOLUTION: In the multi-beam multi-head plotting device equipped with a plurality of plotting heads 41 and 42 having optical systems 5-9 and a polarizer 10 in which laser beams 2 are incident from a laser beam source and the incident laser beams are guided to a plotting area, two acousto-optical elements 12 to adjust the optical axis of the laser beams in the two-dimensional direction are provided on each plotting head. A plurality of beam splitters 3 are preferably provided to guide the laser beams 2 from the laser beam source to the plurality of plotting heads. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-beam multi-head drawing apparatus using a laser as a light source and including a plurality of drawing heads.
[0002]
[Prior art]
Conventionally, a multi-head laser engraving machine capable of engraving different patterns with two exposure heads using an Nd: YAG laser has been disclosed (for example, see Patent Document 1). This multi-head laser engraving machine is used for engraving, for example, radio panels of plastic parts.
[0003]
On the other hand, as an example of a conventional multi-beam / multi-head drawing apparatus, as shown in FIG. 5, in a drawing apparatus having a laser 52 as a light source and an AOM (acousto-optic element) 51 mounted for recording switching, The laser beam 54 from the laser 52 is reflected by the reflection mirror 53, passes through the condenser lens 55, AOM 51, and lens 56, is reflected by the reflection mirror 57, is deflected by the deflector 58, and then passes through the fθ lens 59. Then, it is reflected by the folding mirror 60 and imaged on the recording medium.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-193156
[Problems to be solved by the invention]
However, in the multi-head laser engraving machine described in Patent Document 1, high-accuracy image coupling between exposure heads is indispensable. However, the engraving machine proposed in this document can achieve this. There is a problem that it is difficult.
[0006]
In the multi-beam / multi-head drawing apparatus shown in FIG. 5, it is necessary to use a high-speed deflector to shorten the drawing time, but there is a limit to the increase in the speed of the deflector. In addition, in order to align the scanning lines at the image breaks between the drawing heads, it is necessary to perform mechanical position adjustment, and this adjustment requires a long time.
[0007]
Therefore, the present invention has been made in view of the problems in the conventional multi-beam / multi-head drawing apparatus and the like, and can easily perform high-precision image coupling between the drawing heads, thereby reducing the drawing time. An object of the present invention is to provide a multi-beam multi-head drawing apparatus that can be shortened.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 includes a laser light source, a plurality of optical systems each having a laser beam incident from the laser light source and guiding the incident laser beam to a drawing region, and a polarizer. In a multi-beam / multi-head drawing apparatus provided with a drawing head, each drawing head is provided with two acoustooptic elements for adjusting the optical axis of the laser beam in a two-dimensional direction.
[0009]
According to the first aspect of the present invention, since the drawing head includes two AOM units that can adjust the optical axis of the laser beam in a two-dimensional direction, the position of the imaging plane can be freely changed. Therefore, pitch adjustment and position adjustment can be freely performed, and image position adjustment between the drawing heads can be easily performed. Also, by having two beams in each drawing head, the drawing time can be reduced to ½ of the conventional time.
[0010]
According to a second aspect of the present invention, in the multi-beam / multi-head drawing apparatus according to the first aspect, a single laser light source and a plurality of beam splitters for guiding laser light from the laser light source to the plurality of drawing heads are provided. It is characterized by.
[0011]
According to the second aspect of the present invention, since laser light can be provided to a plurality of drawing heads with one laser light source, the replacement work of the laser light source, which is a consumable item, can be completed only once, and maintainability is improved. Can be improved. Further, since the laser alone is expensive, an inexpensive apparatus can be provided by branching the laser beam with only one light source.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 shows an embodiment of a multi-beam / multi-head drawing apparatus according to the present invention. This multi-beam / multi-head drawing apparatus branches one laser light source 1 and laser light 2 from the laser light source 1. And a plurality of drawing heads 41 to 44 using the laser beam branched by the beam splitter 3 as a light source. As shown in FIG. 2, each of the drawing heads 41 to 44 includes an ND filter 5, a beam splitter 6, reflection mirrors 7, 8, and 9, a deflector 10, an fθ lens 11, and two AOMs. A unit 12 and a folding mirror 17 are provided.
[0014]
The laser light source 1 is disposed on the optical base 13 and is a gas laser or a solid excitation laser, and its output is a parallel light beam.
[0015]
The configuration of the drawing heads 41 to 44 provided on the optical base 13 is different only in the transmittance of the ND filter 5 for adjusting the light amount, and the other configurations are the same.
[0016]
The condensing lens 15 disposed in front of the AOM unit 12 condenses the laser light 2 in the AOM crystal, and is disposed to improve rising of the switching speed of image data.
[0017]
On the other hand, the lens 16 disposed behind the AOM unit 12 is disposed to adjust the beam diameter incident on the fθ lens 11 to a desired beam size in order to obtain an appropriate beam size on the imaging plane.
[0018]
As shown in FIG. 3, optical crystal media 19 and 20 that can be adjusted so as to be deflected in the X and Y directions are arranged in the AOM unit 12. The optical crystal media 19 and 20 are used as an acoustooptic device for electrically controlling the beam position. That is, when an acoustic wave enters the optical crystal media 19 and 20, a wave having a certain refractive index is generated, and the laser light is diffracted into several while passing through the crystal. Here, the optical crystal media 19 and 20 are arranged so that the primary diffraction light beam has the maximum efficiency. Since the deflection angle θ of the light beam is proportional to the acoustic frequency f as shown in (Equation 1), the optical axis can be changed in the XY directions by changing the acoustic frequency f.
[0019]
θ = λ · f / V (formula 1)
Here, θ: angle between 0th-order light and primary light λ: light wavelength f: acoustic frequency V: speed of sound in the optical crystal medium.
[0020]
As shown in FIG. 3A, the AOM optical crystal medium 19 of the AOM unit 12 is disposed horizontally on the optical base 13 of the drawing head 41, and the laser beam is transmitted to the zeroth order by the acoustic frequency f while passing through the crystal. The light 21 and the primary light 22 are separated. The separated lights 21 and 22 pass through the optical crystal body 20 arranged perpendicular to the drawing head base. At this time, by changing the acoustic frequency f of the optical crystal medium 19, it can be separated in the X direction from the relationship of (Equation 1), and the Y direction can be changed by changing the acoustic frequency f of the optical crystal medium 20. Adjustment is possible.
[0021]
The drawing head 41 is provided with an aperture 26 that separates the 0th-order light 21 and 23 and the first-order light 22 and 24 after the lens 16 after passing through the AOM unit 12.
[0022]
The deflector 10 uses a galvanometer mirror, a polygon mirror, or the like.
[0023]
Next, the operation of the multi-beam / multi-head drawing apparatus having the above configuration will be described.
[0024]
As shown in FIG. 1, when the number of drawing heads is four, the laser light amount of the drawing head 41 is transmitted through the beam splitter 3 by 50% and reflected by 50%. The light transmitted through the drawing head 41 is branched by the beam splitter 3 of the drawing head 42 and further transmitted to the drawing head 43 with the drawing head 44. Since each beam splitter 3 is transmitted / reflected at 50%, the drawing head 41 has the ND filter 5 with a transmittance of 12.5%, the drawing head 42 has the ND filter 5 with a transmittance of 25%, and the drawing head 43. Is mounted with an ND filter 5 having a transmittance of 50%, and the light amounts of the respective drawing heads 41 to 44 are the same.
[0025]
The laser beam 2 that has passed through the ND filter 5 in the drawing head 41 is further separated by a beam splitter 14 that separates the optical path into two as shown in FIG. The light transmitted through the beam splitter 14 is turned 90 ° through the reflection mirror 7 and enters the AOM unit 12 through the condenser lens 15. Then, after passing through the AOM unit 12, it passes through the lens 16, is turned back 90 ° by the polarizing beam splitter 6, enters the mirror surface of the polarizer 10 through the reflection mirror 9, passes through the fθ lens 11, and is turned back into the mirror 17. And forms an image on the image plane.
[0026]
On the other hand, the light reflected by 90 ° by the beam splitter 14 passes through the AOM unit 12, changes its polarization direction by 90 ° through the reflection mirror through the λ / 2 plate 18, passes through the polarization beam splitter 6, and is reflected by the reflection mirror 9. And is incident on the mirror surface of the deflector 10, passes through the fθ lens 11, is reflected by the folding mirror, and forms an image on the imaging surface. Here, as shown in FIG. 4, by changing the acoustic frequency f in the above-described manner, the beam at the imaging position is changed in the XY directions, thereby enabling high-precision image coupling between the drawing heads.
[0027]
A recording medium 25 is disposed on the image plane, and image data is modulated by AOM and recorded. The recording medium 25 is wound around a cylindrical drum (not shown), a stage on a plane on which the recording medium 25 is provided is moved, or the recording medium 25 is sandwiched between rollers and fed using a drive mechanism. Are moved in the sub-scanning direction. The number of the drawing heads 41 to 44 can be increased by the main scanning width of the recording medium 25.
[0028]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a multi-beam / multi-head drawing apparatus that can easily perform high-precision image coupling between drawing heads and can reduce drawing time. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a multi-beam / multi-head drawing apparatus according to the present invention, in which (a) is a plan view and (b) is a front view.
2 is a plan view showing a drawing head of the multi-beam / multi-head drawing apparatus of FIG. 1; FIG.
3A and 3B are diagrams showing an AOM unit of the multi-beam / multi-head drawing apparatus of FIG. 1, wherein FIG. 3A is a plan view and FIG. 3B is a front view.
4A and 4B are variable diagrams of imaging position beams in the multi-beam / multi-head drawing apparatus according to the present invention, in which FIG. 4A is a drawing head and FIG. 4B is an imaging position beam of the other drawing head. FIG.
FIG. 5 is a schematic view showing an example of a conventional multi-beam / multi-head drawing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laser light source 2 Laser beam 3 Beam splitter 5 ND filter 6 Deflection beam splitter 7-9 Reflection mirror 10 Deflector 11 f (theta) lens 12 AOM unit 13 Optical base 14 Beam splitter 15 Condensing lens 16 Lens 17 Folding mirror 18 (lambda) / 2 board 19 Optical crystal medium 20 Optical crystal medium 21 0th order light (X direction)
22 Primary light (X direction)
23 0th order light (Y direction)
24 Primary light (Y direction)
25 Recording medium 26 Aperture 41 to 44 Drawing head

Claims (2)

In a multi-beam / multi-head drawing apparatus comprising a laser light source, and a plurality of drawing heads each having an optical system that guides the laser light from the laser light source and guides the incident laser light to a drawing region and a polarizer,
2. A multi-beam / multi-head drawing apparatus, wherein each drawing head is provided with two acousto-optic elements for adjusting the optical axis of the laser beam in a two-dimensional direction. 2. The multi-beam / multi-head drawing apparatus according to claim 1, further comprising one laser light source and a plurality of beam splitters for guiding laser light from the laser light source to the plurality of drawing heads.

Images