JP2710519B2 - Multi-beam recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam recording apparatus for irradiating a recording surface with a plurality of light beams.

[0002]

2. Description of the Related Art FIG. 16 shows a conventional multi-beam recording apparatus. As shown in FIG. 1, the multi-beam recording apparatus includes a plurality of light source units (only one light source unit 12 is shown in the drawing) arranged at regular intervals from each other, and a reduction unit including lenses L20 and L21. Optical system 20 and lens L22
To L24, and lenses L25 and L26.
An afocal optical system 34 composed of

The light source unit 12 includes a semiconductor laser 14, and a laser beam from the semiconductor laser 14 is converted into a parallel beam by a collimator lens 16,
Further, the light passes through the aperture 18 and is incident on the reduction optical system 20 so as to be parallel to the optical axis Z. In this reduction optical system 20, as shown in FIG. 16, the rear focal point of the lens L20 coincides with the front focal point of the lens L21 to form a so-called afocal system. A laser beam parallel to Z is emitted. Then, after the laser beam emitted from the reduction optical system 20 is scaled to an appropriate magnification by the zoom lens 32, the laser beam is condensed on the focal plane FP3 via the afocal optical system 34 and is focused on the focal plane FP3. The light is irradiated onto the recording surface RS to be arranged. Since the chief ray of each laser beam is perpendicular to the focal plane FP3, even when the distance between the focal plane FP3 and the recording plane RS varies, magnification is not changed and high-precision drawing is possible.

[0004] Further, the laser beam from another light source unit not shown is also recorded on the recording surface R in the same manner as described above.
Irradiated on S, a plurality of beam spots are simultaneously formed on the recording surface RS.

[0005]

The conventional multi-beam recording apparatus is constructed as described above, and has a recording surface R at one time.
In order to increase the number of beam spots formed in S, that is, the number of channels, it is necessary to make the lens larger. This is because, as can be seen from the figure, in the conventional example, in order to increase the number of channels, the light source unit 12 must be added in a direction perpendicular to the optical axis Z, and as a result, Therefore, it is necessary to increase the size of the lens L20. Therefore, there is a problem that the aberration of the lens L20 is deteriorated and a problem that the cost of the lens L20 is increased.

In order to reduce the size of the multi-beam recording apparatus by reducing the size of the optical system shown in FIG. 16, it is necessary to shorten the focal length f0 of the lens L20 to shorten the optical path length. If the length is shortened, the F number of the optical system becomes smaller, and more lenses are required to secure the same optical performance as the optical system of FIG. As a result, although the optical path length itself becomes shorter, the number of constituent lenses increases, and the cost and weight of the apparatus increase.

Conversely, if the number of constituent lenses is reduced with emphasis on the number of constituent lenses, the optical performance deteriorates and various aberrations occur. Therefore, even though the light source units 12 are arranged at equal intervals, the mutual intervals of the beam spots irradiated on the recording surface RS via the optical system, that is, the beam pitch becomes non-uniform, The shape deteriorates. Further, since the principal ray of each laser beam is not perpendicular to the focal plane FP3, the focal plane FP3 and the recording plane RS
If the distance from the distance fluctuates, magnification fluctuation (fluctuation in beam pitch) occurs, and the writing quality is degraded.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-beam recording apparatus which is compact and capable of performing high-precision drawing even at an increased number of channels at a low cost. I do.

[0009]

According to a first aspect of the present invention, there is provided a light source unit for generating a plurality of light beams, and a reduction optical system, and a plurality of light beams from the light source unit via the reduction optical system. A multi-beam recording apparatus for irradiating a recording surface with a light, wherein the reduction optical system is constituted by a reflecting mirror having power and an optical element having power, and And the focal point of the optical element.

According to a second aspect of the present invention, the reflecting mirror is constituted by a parabolic mirror, and the optical element is constituted by a stereoscopic projection lens.

According to a third aspect of the present invention, the reflecting mirror and the optical element are constituted by parabolic mirrors having different focal lengths.

According to a fourth aspect of the present invention, the reflecting mirror is constituted by a spherical mirror, and the optical element is constituted by an equal solid angle projection lens.

According to a fifth aspect of the present invention, an afocal optical system is provided between the reduction optical system and the recording surface, and the optical axis of the afocal optical system is set at a predetermined distance from the optical axis of the reduction optical system. Only shifted in parallel.

[0014]

According to the first aspect of the present invention, the reduction optical system includes a reflecting mirror having power and an optical element having power, and the focal point of the reflecting mirror and the focal point of the optical element are matched. An afocal system is formed. In particular, since the reflector can be easily manufactured with high precision,
A reduction optical system having excellent optical performance can be configured at low cost. In addition, a large-diameter and small F-number can be easily obtained.

According to the second aspect of the present invention, the reflecting mirror is a parabolic mirror, and the optical element is a stereoscopic projection lens, that is, as shown in FIG. And when the image height is hi,

[0016]

(Equation 1)

Here, f is a lens having an image height characteristic represented by the focal length of the lens.

According to the third aspect of the present invention, the reflecting mirror and the optical element are each constituted by a parabolic mirror having a different focal length.

According to the fourth aspect of the present invention, the reflecting mirror is formed of a spherical mirror, and the optical element is formed of a solid angle projection lens,

[0020]

(Equation 2)

Where f is the focal length of the lens, θi is the angle of incidence on the lens (see FIG. 17), and hi is the image height (FIG. 17).
) And a lens having an image height characteristic represented by

Therefore, when a light beam parallel to the optical axis and having a light ray height hi from the optical axis is incident on the reduction optical system, the optical system outputs the light beam from the reduction optical system. Where hi '= m.hi, where m satisfies the relationship expressed by the magnification of the reduction optical system, and a light beam parallel to the optical axis is emitted.

In the invention according to claim 5, an afocal optical system is further provided between the reduction optical system and the recording surface. The optical axis of the afocal optical system is shifted parallel to the optical axis of the reduction optical system by a predetermined distance, so that the entire light beam emitted from the reduction optical system covers the entire incident surface of the afocal optical system. Incident.

[0024]

【Example】

A. First Embodiment FIGS. 1 and 2 are a plan view and a side view showing a first embodiment of a multi-beam recording apparatus according to the present invention. This multi-beam recording apparatus includes a light source unit 10 for generating a plurality of laser beams, a reduction optical system 20, an afocal optical system 30, and a rotating cylinder 40. While rotating the rotating cylinder 40 in the main scanning direction X with the FM wound, the laser beam from the light source unit 10 is synchronized with the rotating operation of the rotating cylinder 40 via the reduction optical system 20 and the afocal optical system 30 to rotate the laser beam. By moving in the sub-scanning direction Y substantially perpendicular to the scanning direction X, a desired image is drawn on the photosensitive material FM.

FIG. 3 is a front view of the light source unit 10.
As shown in FIG. 1, the light source unit 10 includes a plurality of light source sections 12 arranged at a constant pitch Pa.
Each light source unit 12 includes a semiconductor laser 14 and a collimator lens 16. After a laser beam from the semiconductor laser 14 is collimated by the collimator lens 16, the light beam passes through an aperture 18 of the light source unit 12. The light is emitted parallel to the optical axis Z (FIGS. 1 and 2). The aperture 18 is arranged on the focal plane of the parabolic mirror 22. As can be seen from FIG. 3, the light source units 12 are arranged so as to partially overlap each other in the main scanning direction X, but this is because the adjacent scanning lines are separated from each other due to the mechanical size of the light source unit 12. This is to prevent the occurrence of so-called scanning cracks. In order to prevent mechanical interference with the reduction optical system 20, in this embodiment, the light source unit 1 is used.
2 are arranged in two groups (FIG. 2).

FIG. 4 is a diagram showing the reduction optical system 20. In the reduction optical system 20, the parabolic mirror 22 and the stereoscopic projection lens 24
Are arranged so that their focal points coincide with each other at a predetermined position A, thereby forming an afocal system. Therefore, the laser beam LB parallel to the optical axis Z from the light source unit 10
When 1 is incident on the reduction optical system 20, the laser beam LB3 from this reduction optical system 20 is also parallel to the optical axis Z.

The three-dimensional projection lens 24 has, for example, three lenses L1, L2, L3 as shown in FIG.
When the incident angle of the laser beam LB2 reflected by the parabolic mirror 22 to the stereoscopic projection lens 24 is θi, and the image height (light height from the optical axis Z) is hi ′,

[0028]

(Equation 3)

Here, f24 has an image height characteristic represented by the focal length of the stereoscopic projection lens 24. Accordingly, the size of the aperture image of the light source unit 10 and the height hi from the optical axis Z are simultaneously increased by the reduction optical system 20 at the magnification m1 (=
f24 / f22) and the image is formed on the rear focal plane FP1 of the stereoscopic projection lens 24. The reason is as follows. As shown in FIG. 4, object height (light height from optical axis Z)
When the laser beam LB1 parallel to the optical axis Z enters the reduction optical system 20 at hi, the laser beam LB2 reflected by the parabolic mirror 22 moves the position A away from the parabolic mirror 22 by a focal distance f22 to an angle θi. Pass by. At this time, from the optical characteristics of the parabolic mirror 22,

[0030]

(Equation 4)

The relationship expressed by Therefore, substituting Equation 4 into Equation 3 gives

[0032]

(Equation 5)

Is obtained. Therefore, the equal beam pitch P
The laser beam LB emitted from the light source unit 10 at a
1 is a rear focal plane FP1 of the stereoscopic projection lens 24, respectively.
And an intermediate image of the aperture 18 is formed on the surface FP1 at regular intervals. The aperture image is
Only when the aperture 18 is arranged on the focal plane of the parabolic mirror 22, an image is formed on the focal plane FP1. If the aperture 18 is offset from the focal plane of the parabolic mirror 22,
The aperture image shifts from the focal plane FP1, and the shift amount is determined by the longitudinal magnification of the reduction optical system 20.

As shown in FIGS. 1 and 2, the afocal optical system 30 is provided between the reduction optical system 20 and the rotary cylinder 40, and includes a zoom lens 32 composed of lenses L4 to L9 and lenses L10 and L11. And an afocal optical system 34 composed of In this afocal optical system 30, the rear focal plane of the zoom lens 32 coincides with the front focal plane of the afocal optical system 34 on the plane FP2, and an afocal system is formed as a whole. The front focal plane of the zoom lens 32 coincides with the rear focal plane of the stereoscopic projection lens 24 of the reduction optical system 20 on the plane FP1, while the photosensitive material F is placed on the rear focal plane of the afocal optical system.
M (recording surface) is located. Therefore, the intermediate image (aperture image) formed on the surface FP1 is reduced at an appropriate magnification by the afocal optical system 30, and the aperture image (beam spot) is formed on the photosensitive material FM.
Is formed as Therefore, the beam spots on the photosensitive material FM are arranged at equal intervals, that is, the beam pitch becomes uniform.

As described above, according to this embodiment, a plurality of laser beams LB1 from the light source unit 10 are collected at one point by the parabolic mirror 22, and the laser beams from the points are further passed through the three-dimensional projection lens 24. Optical system 2
Since the light is emitted from zero, it is possible to prevent the reduction optical system 20 from increasing in size even when the number of channels is increased. That is, the manufacturing technology of the parabolic mirror 22 is already established, and it is possible to easily produce a high-precision mirror at low cost. Further, the processing surface of the parabolic mirror 22 is one. In view of its large diameter and small F number, it is advantageous in terms of miniaturization and cost reduction of the apparatus. In addition, since the laser beam LB3 parallel to the optical axis Z is emitted from the reduction optical system 20 while maintaining the relationship of Equation 5, the beam pitch on the photosensitive material FM (recording surface) becomes uniform, and high accuracy is achieved. Can be drawn. Further, in this embodiment, as shown in FIGS. 1 and 2, each laser beam is irradiated substantially perpendicularly to the photosensitive material FM, so that the photosensitive material FM moves along the optical axis Z. Can be drawn on the photosensitive material FM with high accuracy without being affected by magnification change.

B. Second Embodiment FIG. 5 is a plan view showing a second embodiment of the multi-beam recording apparatus according to the present invention. The second embodiment is significantly different from the first embodiment in that a parabolic mirror 26 is used instead of the stereoscopic projection lens 24. In other words, the reduction optical system 20 is composed of two parabolic mirrors 22 and 26 which are arranged to face each other while making their focal points coincide with each other at the point A, and apply the laser beam from the light source unit 10 to the parabolic mirrors 22 and The light is sequentially reflected at 26 and irradiates the photosensitive material FM via the afocal optical system 30 having the same configuration as that of the first embodiment. The focal length f22 of the parabolic mirror 22 and the parabolic mirror 2
6 is different from the focal length f26, and even when the parabolic mirror 26 is used in place of the stereoscopic projection lens 24, the laser beam LB1 parallel to the optical axis Z is reduced by the reduction optics as in the first embodiment. When the laser beam LB3 is incident on the system 20, the laser beam LB3 parallel to the optical axis Z satisfies the relationship of the expression (5), and is reduced.
Emitted from 0. The reason will be described below.

For example, the object height (light height from the optical axis Z) hi
When the laser beam parallel to the optical axis Z is incident on the reduction optical system 20, the relationship of Expression 4 is established as described above. On the other hand, also in the parabolic mirror 26,

[0038]

(Equation 6)

The relationship expressed by the following holds. Therefore, from Equations 4 and 6

[0040]

(Equation 7)

Is obtained. Therefore, also in the second embodiment, the equal beam pitch Pa is set by the reduction optical system 20.
The laser beam LB1 emitted from the light source unit 10
Are imaged on the rear focal plane FP1 of the parabolic mirror 26 at an equal pitch, so that the same effect as in the first embodiment can be obtained.

C. Third Embodiment In the above embodiment, the reduction optical system 20 is configured by the parabolic mirror 22 and the stereoscopic projection lens 24 (first embodiment), or is configured by two parabolic mirrors 22 and 26 ( The second embodiment) can be constituted by a spherical mirror 28 and an equal solid angle projection lens 29, for example, as shown in FIG. Is obtained. Hereinafter, the reason will be described.

When the laser beam LB1 parallel to the optical axis Z is incident on the spherical mirror 28, spherical aberration occurs due to the optical properties of the spherical mirror. Here, for example, the incident laser beam L
Assuming that the ray height of B1 from the optical axis Z is hi and the angle at which the laser beam LB2 reflected by the spherical mirror 28 crosses the optical axis Z is θi, the reflected laser beam LB2 is

[0044]

(Equation 8)

However, the relationship represented by f28 is established by the focal length of the spherical mirror 28. On the other hand, for example, three lenses L
The equi-solid angle projection lens 29 composed of 12 to L14 is

[0046]

(Equation 9)

Here, f29 has an optical characteristic represented by the focal length of the equal solid angle projection lens 29, and hi 'has a light height of the laser beam from the equal solid angle projection lens 29.
Therefore, substituting equation 8 into equation 9 gives

[0048]

(Equation 10)

Is obtained. As described above, in this embodiment, the combination of the spherical mirror 28 and the equal solid angle projection lens 29 is
0, and the aberration opposite to the aberration generated by the spherical mirror 28 is given by the equal solid angle projection lens 29 to cancel out the aberration as a whole in the reduction optical system 20. Characteristic is obtained.

In the third embodiment, the configuration other than the reduction optical system 20 is substantially the same as that of the first and second embodiments, and the description of the configuration and operation will be omitted.

D. Fourth Embodiment FIGS. 7 and 8 are a perspective view and a plan view, respectively, showing a multibeam recording apparatus according to a fourth embodiment of the present invention.
This embodiment is significantly different from the first embodiment in two points. First, as a first point, in the first embodiment, the parabolic mirror 22 is used.
In the fourth embodiment, a part of the parabolic mirror 22 is used,
It is also pointed out that the region 22a of the parabolic mirror 22 deviating from the main axis PA is used. Note that a parabolic mirror constituted only by this region 22a is generally called an "off-axis parabolic mirror", and in the following description, the parabolic mirror of this embodiment is off-axis. Call.

The second point is that, in the fourth embodiment, the optical axis Z1 of the reduction optical system 20 and the optical axis Z2 of the afocal optical system 30 are shifted in parallel in the sub-scanning direction Y by a predetermined distance ΔY. Is a point. Of course, there is no particular problem in practical use even if the optical axes of both are matched as in the first embodiment (FIG. 1). However, when the off-axis parabolic mirror 22a is used, the reduction optical system is used. The laser beam LB3 from 20 passes through only a part of the afocal optical system 30. On the other hand, in the fourth embodiment, as shown in FIG. 8, the laser beam LB3 from the reduction optical system 20 is guided to the photosensitive material FM using the entire afocal optical system 30 by shifting the optical axis. Therefore, the afocal optical system 30 can be made more compact.

In FIG. 7, reference numeral 50 denotes a base movable in the sub-scanning direction Y, and includes a light source unit 10, an off-axis parabolic mirror 22a, a stereoscopic projection lens 24, and a folding mirror 5.
2. The zoom lens 32, the folding mirror 54, and the afocal optical system 34 are fixed to the base 50 by a support holder (not shown) to form a recording head. A drive mechanism (not shown) is attached to the printhead, and the drive mechanism is configured to move the printhead in the sub-scanning direction Y. Further, the zoom lens 32 is provided with a pulse motor 56 for adjusting the magnification.

FIG. 9 is a plan view showing the arrangement relationship of the light source units 12. As shown in FIG. 1, in the light source unit 10, a plurality of light source sections 12 are two-dimensionally arranged at an equal pitch Pa. However, as in the first embodiment, the main scanning direction X is shifted by (scanning pitch PS) / (magnification M of the optical system) in order to prevent scanning cracks, and are arranged so as to partially overlap each other. .

In the multi-beam recording apparatus thus configured, a plurality of laser beams LB1 emitted from the light source unit 10 and parallel to the optical axis Z1 are reflected by the off-axis parabolic mirror 22a, respectively, and then stereoscopically projected. Lens 2
4, the light is condensed on the rear focal plane FP1 and the aperture 18 is arranged on the focal plane of the off-axis parabolic mirror 22a, so that an intermediate image (aperture image) is formed on the plane FP1. You. Here, as described in the first embodiment, the image height of each intermediate image satisfies Equation 5 with respect to the ray height of the laser beam LB1 from the light source unit 12, so that a plurality of intermediate images are formed at equal intervals. Formed on FP1. And
These intermediate images are reduced at an appropriate magnification by the afocal optical system 30, and are formed as images (beam spots) on the photosensitive material FM (recording surface) wound around the rotating cylinder 40.

As described above, also in the fourth embodiment, similarly to the first embodiment, the laser beam LB1 from the light source unit 10 passes through the parabolic mirror 22 and the stereoscopic projection lens 24 while satisfying the expression (5). Since an intermediate image is formed on the surface FP1 and the image is formed on the photosensitive material FM by the afocal optical system 30, the same effects as in the first embodiment can be obtained.

In the fourth embodiment, the case where the aperture 18 is used has been described.
8 is not an essential component. When no aperture is provided, as shown in FIG. 10, the laser beam LB1 emitted from the semiconductor laser 14 and further collimated by the collimator lens 16 is reflected by the parabolic mirror 22,
A beam waist is formed at the focal position D. Since this position is the front focal position of the stereoscopic projection lens 24, the beam waist of the laser beam LB3 that has passed through the stereoscopic projection lens 24 is formed on the rear focal plane FP1 of the stereoscopic projection lens 24. Hereinafter, similarly, the afocal optical system 3
4, a beam waist is also formed on the photosensitive material FM coincident with the rear focal plane, so that drawing can be performed with a minute beam spot, and high-precision drawing can be performed as in the case where an aperture is provided.

Further, the afocal optical system 30 is not an essential component in configuring the multi-beam recording apparatus, and as shown in FIG.
0, and in this case, the stereoscopic projection lens 2
4, a photosensitive material FM (recording surface) is arranged on the rear focal plane FP1.

Further, the afocal optical system 30 is
As shown in FIG. 2, it may be constituted only by the zoom lens 32. In this case, the rear focal plane F of the zoom lens 32
The photosensitive material FM is disposed on P2.

In each of the above embodiments, the rear focal plane of the zoom lens (afocal system) 32 coincides with the front focal plane of the afocal optical system 34 to form the afocal optical system 30. However, it is not essential that the individual optical systems constituting the optical system 30 (for example, the lens 32 and the optical system 34 correspond to the first embodiment) are afocal optical systems. If it is an afocal system, it is enough.

E. Fifth Embodiment FIG. 13 is a diagram showing a multibeam recording apparatus according to a fifth embodiment of the present invention. The fifth embodiment is almost the same as the first embodiment except that the light source unit 10 is different. Therefore, here, the configuration of the light source unit 10 will be described, and the description of the other configurations will be omitted.

In the light source unit 10, a solid-state laser 62 is provided as a laser beam generating source instead of the semiconductor laser 12, and one laser beam LB 4 from the solid-state laser 62 is incident on a beam splitter 64. Have been. Therefore, the incident beam L
B4 is split into a plurality of beams by the beam splitter 64, then enters a multi-channel modulator 66, is modulated according to image signals, and is emitted from the light source unit 10 toward the reduction optical system 20. Note that a gas laser or the like may be used instead of the solid laser 62.

In this embodiment, as shown in FIG. 13, since the beam waist BW is adjusted to be located at a position corresponding to the aperture 18 of the first embodiment, the beam waist of the divided laser beam is adjusted to the plane FP1. , FP2 and the photosensitive material FM (recording surface), and a sharp image can be recorded on the photosensitive material FM. Of course, since the reduction optical system 20 and the afocal optical system 30 have the same configuration, the same effects as in the fourth embodiment can be obtained.

When the beam splitter 64 is used, the formation position of the beam waist of the divided laser beam is slightly different depending on the channel, but the amount of deviation of the formation position is determined by the longitudinal magnification of the entire system. However,
In this type of recording apparatus, in order to perform high-density drawing, it is common to set a large reduction ratio. Therefore, the shift amount is extremely small, and there is no problem in practical use.

F. Sixth Embodiment In the above description, an apparatus of the type for drawing on the photosensitive material FM wound around the rotary cylinder 40 has been described. However, the present invention relates to a photosensitive material F attached to the inner surface of a cylinder.
The present invention can also be applied to an apparatus of a type for drawing on M.

FIG. 14 is a perspective view showing a scanning system of this type of multi-beam recording apparatus. As shown in the figure, a photosensitive material FM is mounted on an inner peripheral surface of a holder 72 having a shape obtained by dividing a hollow cylinder in parallel with the axial direction thereof. A rotating mirror 74 having a reflecting surface parallel to the center line CL of the curvature of the holder 72 is rotatably supported by the pair of frames 76, 76.
The rotating mirror 74 is connected to the motor 8 via a belt 78.
0, so that the mirror 74 rotates in accordance with the rotation of the motor 80. A fixed mirror 78 is fixed to the frame 76 at a position below the rotating mirror 74.

A ball screw 82 is inserted between the frames 76 and 76.
, And a beam head 84 is screwed into the ball screw 82. Therefore, when the motor 86 connected to one end of the ball screw 82 is rotated, the beam head 84 is moved in the sub-scanning direction Y while being guided by the guides 88.

A right-angle prism 90 is mounted on the beam head 84. A plurality of laser beams LB from the light source unit 10 are reflected via the reduction optical system 20 and the afocal optical system 30, and
The light is incident on the upper condenser lens 92. This condenser lens 92
Is irradiated on the photosensitive material FM via a fixed mirror 78 and a rotating mirror 74.

Accordingly, the motor 80 is driven to rotate the rotary mirror 74 to scan the laser beam from the afocal optical system 30 in the main scanning direction X, and the motor 86 is driven to move the beam head 84 in the sub-scanning direction. Y
, A desired image can be drawn on the photosensitive material FM.

G. Seventh Embodiment FIG. 15 is a diagram showing a multibeam recording apparatus according to a seventh embodiment of the present invention. This multi-beam recording apparatus has a light source unit 1 for emitting two laser beams.
0, a reduction optical system 20 including an off-axis parabolic mirror 22 and a stereoscopic projection lens 24, an afocal optical system 30 including two lenses L18 and L19, and a drawing object 122 are mounted and two-dimensionally vector-scanned. XY stage 100 is provided.

In the light source unit 10, the laser beam LB 5 from the argon laser 110 is applied to the shutter 1.
The beam enters the beam splitter 116 via the mirror 12 and the reflection mirror 114 and is partially reflected, while the component transmitted through the beam splitter 116 is reflected by the mirror 11.
8 reflected. As described above, in this light source unit 10, one laser beam LB5 is split into two parallel laser beams LB6 and LB7 and then emitted toward the reduction optical system 20. Although not shown in the figure, the beam splitter 116 and the mirror 11
A drive mechanism 8 is connected to each other and can be independently moved in the propagation direction Z of the laser beam LB5. The laser beam from the light source unit 10 is adjusted by adjusting the distance between the beam splitter 116 and the mirror 118. LB6
, LB7 can be changed.

The laser beam L from the light source unit 10
B6 and LB7 form an intermediate image at a predetermined position via the reduction optical system 20, and are further reflected by the return mirror 120 and enter the afocal optical system 30. The afocal optical system 30 reduces the intermediate image at an appropriate magnification and forms an image on the object 122 on the XY stage 100. According to the multi-beam recording apparatus, the same image can be simultaneously recorded on the object to be drawn 122 at predetermined intervals, for example, in the regions 122a and 122b. In each of the above-described embodiments, a laser such as the semiconductor laser 14 or the solid-state laser 62 is used as a light source that emits a light beam.

[0073]

As described above, according to the first aspect of the present invention, the reduction optical system is constituted by the reflecting mirror having the power and the optical element having the power, and the focal point of the reflecting mirror and the optics thereof. Since the afocal system is formed by matching the focal point of the element, even if the number of channels is increased, compact and high-precision drawing becomes possible.

According to the second aspect of the present invention, the reflecting mirror is constituted by a parabolic mirror, and the optical element is constituted by a stereoscopic projection lens. According to the third aspect of the present invention,
The reflecting mirror and the optical element are each constituted by a parabolic mirror having a different focal length. Further, according to the invention of claim 4, the reflecting mirror is constituted by a spherical mirror, and the optical element is constituted by an equal solid angle projection lens. Therefore, in any of the second to fourth aspects, if the heights of the laser beams entering and exiting the reduction optical system from the optical axis are hi and hi ', respectively, hi' = m · hi where m Can satisfy the magnification of the reduction optical system, and high-precision drawing can be performed.

According to the fifth aspect of the present invention, even when an afocal optical system is further provided between the reduction optical system and the recording surface, the optical axis of the afocal optical system is adjusted by the reduction optical system. It is shifted parallel to the optical axis of the system by a predetermined distance, and the entire light beam emitted from the reduction optical system can be made incident on the entire incident surface of the afocal optical system. Can be achieved.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a multi-beam recording apparatus according to the present invention.
It is a top view showing an example.

FIG. 2 shows a first example of the multi-beam recording apparatus according to the present invention.
It is a side view which shows an Example.

FIG. 3 is a front view of a light source unit.

FIG. 4 is a diagram showing a reduction optical system.

FIG. 5 shows a second example of the multi-beam recording apparatus according to the present invention.
It is a top view showing an example.

FIG. 6 is a diagram illustrating a reduction optical system.

FIG. 7 shows a fourth embodiment of the multi-beam recording apparatus according to the present invention.
It is a perspective view showing an example.

FIG. 8 shows a fourth embodiment of the multi-beam recording apparatus according to the present invention.
It is a top view showing an example.

FIG. 9 is a plan view showing an arrangement relationship of light source units.

FIG. 10 is a plan view showing a modified example of the multi-beam recording apparatus according to the present invention.

FIG. 11 is a plan view showing another modified example of the multi-beam recording apparatus according to the present invention.

FIG. 12 is a plan view showing still another modified example of the multi-beam recording apparatus according to the present invention.

FIG. 13 is a diagram showing a fifth embodiment of the multi-beam recording apparatus according to the present invention.

FIG. 14 is a diagram showing a sixth embodiment of the multi-beam recording apparatus according to the present invention.

FIG. 15 is a diagram showing a seventh embodiment of the multi-beam recording apparatus according to the present invention.

FIG. 16 is a diagram showing a conventional multi-beam recording apparatus.

FIG. 17 is a diagram illustrating a relationship between an incident angle and an image height.

[Description of Signs] 10 light source unit 20 reduction optical system 22, 26 parabolic mirror 24 stereoscopic projection lens 28 spherical mirror 29 equal solid angle projection lens 30 afocal optical system

Claims (5)

(57) [Claims] 1. A multi-beam recording apparatus comprising: a light source unit that generates a plurality of light beams; and a reduction optical system, and irradiates a plurality of light beams from the light source unit to a recording surface via the reduction optical system. Wherein the reduction optical system includes a reflecting mirror having power and an optical element having power, and a focal point of the reflecting mirror coincides with a focal point of the optical element. Beam recording device. 2. The multi-beam recording apparatus according to claim 1, wherein said reflecting mirror is a parabolic mirror, and said optical element is a stereoscopic projection lens. 3. The multi-beam recording apparatus according to claim 1, wherein said reflecting mirror and said optical element are parabolic mirrors having different focal lengths. 4. The multi-beam recording apparatus according to claim 1, wherein said reflecting mirror is a spherical mirror, and said optical element is an equal solid angle projection lens. 5. An afocal optical system is provided between the reduction optical system and the recording surface, and an optical axis of the afocal optical system is shifted by a predetermined distance in parallel with an optical axis of the reduction optical system. The multi-beam recording apparatus according to claim 1.