JP2003287692A - Light beam scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light beam scanner which can hold a scanning range wide without causing decrease in scanning speed. <P>SOLUTION: A 1st scanning optical device makes a scan with the light beam flux emitted by the light source in a 1st direction. A relay optical system propagates the light beam flux whose travel direction is deflected by the 1st scanning optical device. The light beam flux propagated in the relay optical system is made incident on a 2nd scanning optical device. The 2nd scanning optical device deflects the incident light beam flux and varies the angle of deflection to make a scan with the light beam flux in a 2nd direction crossing the 1st direction. The relay optical system propagates the light beam flux so that when the scan with the light beam flux is made by the 1st scanning optical system, the position where the light beam flux is deflected in the 2nd scanning optical device does not move or the length of a track of the position of the deflection is shorter than that when the relay optical system is not arranged. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam scanning device, and more particularly to a scanning device capable of scanning a light beam in a two-dimensional direction.

[0002]

2. Description of the Related Art A pair of galvanometer mirrors can be used to scan a laser beam in a two-dimensional direction.

As shown in FIG. 3A, the first-stage galvanometer mirror 100 scans a laser beam in a one-dimensional direction (a direction parallel to the plane of the drawing), and the scanned laser beam is the second-stage galvanometer mirror. It is incident on 101. The second-stage galvanometer mirror 101 scans the laser beam in a direction orthogonal to the scanning direction of the first-stage galvanometer mirror 100 (direction perpendicular to the paper surface), so that the laser beam is scanned in the two-dimensional direction.

The already scanned laser beam is incident on the second stage galvanometer mirror 101. Therefore, the galvano mirror 101 in the second stage is replaced with the galvano mirror 10 in the first stage.
If it is moved away from 0, the galvano mirror 101 of the second stage must be made larger. When the galvanometer mirror becomes large, the mirror response deteriorates and the scanning speed decreases. Further, when the lens is arranged in the rear stage of the second-stage galvanometer mirror 101, the lens needs to be enlarged.

As shown in FIG. 3B, if the galvano mirror 101 in the second stage is brought closer to the galvano mirror 100 in the first stage, the galvano mirror can be made smaller. However, interference between mirrors is likely to occur, and the laser beam reflected by the galvano mirror 101 in the second stage may be blocked by the galvano mirror 100 in the first stage.
Therefore, it is difficult to widen the scanning range of the laser beam.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a light beam scanning device capable of maintaining a wide scanning range without causing a reduction in scanning speed.

[0007]

According to one aspect of the present invention, a light source for emitting a light beam bundle, a first scanning optical device for scanning the light beam bundle emitted from the light source in a first direction, and the first scanning optical device A relay optical system for propagating a ray bundle whose traveling direction is swung by the first scanning optical device and a ray bundle propagating through the relay optical system are incident, the incident ray bundle is deflected, and the deflection angle is changed. , A second scanning optical device that scans in a second direction intersecting the first direction, and when the light beam bundle is scanned by the first scanning optical system, the second scanning optical device
In the scanning optical device, the position where the light beam is deflected does not move, or the length of the trajectory of the deflected position is shorter than that when the relay optical system is not arranged. A ray bundle scanning device is provided in which a relay optical system propagates a ray bundle.

Since the deflection point in the second scanning optical device does not move or its locus is short, the second scanning optical device can be made smaller than in the case where the relay optical system is not arranged.

According to another aspect of the present invention, there is provided a first oscillating reflecting mirror for reflecting and oscillating an incident ray bundle to scan the reflected ray bundle in a first direction, and the first oscillating reflector. A relay optical system for propagating the light beam scanned by the dynamic reflecting mirror,
A second oscillating reflecting mirror that scans the reflected light ray bundle in a second direction intersecting the first direction by entering and oscillating the light ray bundle propagating through the relay optical system; The relay optical system forms an image of a first point on the swing center axis of the first swing reflecting mirror at a second point on the swing center axis of the second swing reflecting mirror. A beam scanning device is provided.

When the ray bundle is made incident on the first point of the first swing reflecting mirror, the ray bundle is made incident on the second swing reflecting mirror even if the first swing reflecting mirror is made to swing. The points do not move. Therefore, the size of the second swing reflecting mirror can be reduced.

[0011]

1 is a schematic view of a light beam scanning device according to an embodiment of the present invention. The laser light source 1 emits a laser beam. As the laser light source 1, for example, a carbon dioxide gas laser, a YAG laser, a YLF laser, an excimer laser, or the like can be used. The laser beam emitted from the laser light source 1 is collimated (collimated) by the collimator lens 2.

The collimated laser beam is reflected by the folding mirror 3 and is incident on the first-stage X galvanometer mirror (oscillating reflecting mirror) 4. The X galvanometer mirror 4 scans the incident laser beam in a direction parallel to the paper surface. X
The laser beam scanned by the galvanometer mirror 4 enters the relay optical system 5.

The relay optical system 5 propagates the incident laser beam and makes it enter the second Y galvanometer mirror 6. The Y galvanometer mirror 6 scans the incident laser beam in a direction perpendicular to the paper surface. The laser beam scanned by the Y galvanometer mirror 6 is converged by the fθ lens 7 and is incident on the processing object 10 held by the XY stage 8. The fθ lens 7 minimizes the beam spot size on the surface of the processing object 10.

On the surface of the object 10 to be processed, the direction parallel to the paper surface (horizontal direction) is the X axis, the direction perpendicular to the paper surface is the Y axis, and the direction normal to the surface of the object 10 is the Z axis. XY to do
Consider a Z Cartesian coordinate system. When the X galvanometer mirror 4 is swung, the incident point of the laser beam moves in the X axis direction, and Y
When the galvanometer mirror 6 is swung, the incident point of the laser beam moves in the Y-axis direction. In this way, the laser beam can be scanned in the two-dimensional direction by the X galvano mirror 4 and the Y galvano mirror 6.

The X galvanometer mirror 4 is arranged so that its swing center axis passes through the incident point of the laser beam emitted from the laser light source 1. Therefore, even if the X galvanometer mirror 4 swings, the incident point of the laser beam does not move on the reflecting surface of the X galvanometer mirror 4.

The relay optical system 5 includes a plurality of convex lenses, and forms an image of the incident point of the laser beam on the X galvano mirror 4 on the reflecting surface of the Y galvano mirror 6. The Y galvanometer mirror 6 is arranged so that its swing center axis passes through this image formation point. Therefore, even if the Y galvanometer mirror 6 swings, the X galvanometer mirror 4
The incident point of the laser beam on the image is always imaged on the reflecting surface of the Y galvanometer mirror 6.

Even if the X galvanometer mirror 4 is swung to scan the laser beam, the incident point of the laser beam on the Y galvanometer mirror 6 does not move. At this time, only the angle between the laser beam and the line of intersection between the reflecting surface of the Y galvanometer mirror 6 and the ZX plane changes. Since this angle changes, the laser beam reflected by the Y galvanometer mirror 6 is
It is shaken in the X-axis direction. Further, by swinging the Y galvanometer mirror 6, the laser beam is swung in the Y-axis direction. In this way, the laser beam reflected at the image forming point on the reflecting surface of the Y galvanometer mirror 6 is scanned in the X axis direction and the Y axis direction.

The fθ lens 7 is arranged such that one focus thereof coincides with the image forming point on the reflecting surface of the Y galvanometer mirror 6. Therefore, when the laser beam is scanned in the two-dimensional direction, the laser beam can be converged on the surface of the processing object 10 in an ideal state.

In the above embodiment, the relay optical system 5 images the incident point of the laser beam on the X galvano mirror 4 on the reflecting surface of the Y galvano mirror 6, but it is not always necessary.
The image formation point does not have to be located exactly on the reflecting surface.

If the relay optical system 5 is not arranged, X
When the Y galvanometer mirror 4 is swung, the incident point of the laser beam on the Y galvanometer mirror 6 moves on the reflecting surface thereof. Therefore, it is necessary to make the Y galvanometer mirror 6 large so that the incident point of the laser beam does not deviate from the reflecting surface. Even when the image forming point is located in front of or behind the reflecting surface of the Y galvano mirror 6, if the deviation from the reflecting surface is small, the incident point of the laser beam on the Y galvano mirror 6 is small. The distance traveled by is sufficiently short.

The relay optical system 5 is connected to the Y galvano mirror 6
The optical system may be configured such that the moving distance of the incident point on is shorter than that when the relay optical system 5 is not arranged.
In this case, compared to the case where the relay optical system 5 is not arranged,
The Y galvanometer mirror 6 can be made smaller.

FIG. 2 is a schematic perspective view of a perforation processing apparatus using the light beam scanning apparatus according to the above embodiment. Perforated long paper 20 is fed at a constant speed in the X-axis direction. Laser light source 1, field lens 2, X galvano mirror 4, relay optical system 5, Y galvano mirror 6, f
The θ lens 7 constitutes a light beam scanning device similar to that of the embodiment shown in FIG.

The laser beam focused by the fθ lens 7 enters the paper 20 and forms a hole. Perforations can be formed on the paper 20 by scanning the laser beam while emitting the pulsed laser beam from the laser light source 1.

When the X galvanometer mirror 4 is swung, the incident position of the laser beam on the paper 20 moves in the X-axis direction which is the feeding direction of the paper 20. When the Y galvanometer mirror 6 is swung, the incident position of the laser beam on the paper 20 moves from one end to the other end in the width direction (Y-axis direction) of the paper 20.

Since the paper 20 is fed at a constant speed in the X-axis direction, when the laser beam is scanned in the direction parallel to the Y-axis, the direction in which the perforations extend extends from the width direction of the paper 20. The direction in which the perforations extend is made parallel to the width direction of the paper 20 by oscillating the X galvanometer mirror 4 and scanning the laser beam also in the X-axis direction at the same speed as the feeding speed of the paper 20. You can

When forming perforations on a wide paper, the swing angle of the laser beam by the Y galvanometer mirror 6 must be increased. When the Y galvanometer mirror 6 is arranged close to the X galvanometer mirror 4, if the swing angle of the Y galvanometer mirror 6 is increased, the scanned laser beam is blocked by the X galvanometer mirror 4. I will end up. In the beam bundle scanning apparatus according to the above-described embodiment, the Y galvano mirror 6 can be moved away from the X galvano mirror 4, so that the scanned laser beam is not blocked by the X galvano mirror 4 and the Y galvano mirror 4 is not blocked. The swing angle of 6 can be increased.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0028]

As described above, according to the present invention,
By disposing the relay optical system between the pair of swing reflecting mirrors, the swing angle of the laser beam can be increased without increasing the size of the swing reflecting mirror in the subsequent stage.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a light beam scanning device according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a perforation processing apparatus using the light beam scanning device according to the embodiment of the present invention.

FIG. 3 is a schematic view showing an arrangement of a pair of conventional galvanometer mirrors.

[Explanation of symbols]

1 laser light source 2 Collimation lens 3 folding mirror Galvano mirror for 4X 5 Relay optical system 6 Y galvo mirror 7 fθ lens 8 XY stage 10 Object to be processed 20 paper

Claims (7)

[Claims] 1. A light source for emitting a bundle of rays, a first scanning optical device for scanning the bundle of rays emitted from the light source in a first direction, and a traveling direction of the first scanning optical device. A relay optical system for propagating a ray bundle, a ray bundle propagated through the relay optical system is incident, the incident ray bundle is deflected, and the deflection angle is changed,
A second scanning optical device that scans in a second direction intersecting with the first direction, and when the light beam is scanned by the first scanning optical system, the inside of the second scanning optical system The relay optical system is configured so that the position where the ray bundle is deflected does not move or the length of the trajectory of the deflected position is shorter than that when the relay optical system is not arranged. A beam bundle scanning device for propagating a bundle. 2. The first scanning optical device and the second scanning optical device each include an oscillating reflecting mirror, and the reflecting mirror reflects and oscillates a bundle of light beams, thereby reflecting the reflected light beam. The light beam scanning device according to claim 1, wherein the beam traveling direction is swung. 3. A reflecting mirror of the first scanning optical device swings so that a position of incidence of a light beam emitted from the light source does not move, and the relay optical system includes the first scanning optical device. 3. The light beam scanning device according to claim 2, wherein the incident point of the light beam bundle on the reflecting mirror is imaged on the reflecting surface of the reflecting mirror of the second scanning optical device. 4. The swing center axis of the reflecting mirror of the second scanning optical device passes through an image point of an incident point of a bundle of rays on the reflecting mirror of the first scanning optical device. Beam bundle scanning device. 5. An fθ lens for converging a light flux scanned by the second scanning optical device onto a processing object, wherein the fθ lens is arranged so that its focal point coincides with the image point. 5. The beam bundle scanning device according to claim 4, wherein the f [theta] lens is formed. 6. A first oscillating reflecting mirror that scans a reflected ray bundle in a first direction by reflecting and oscillating an incident ray bundle, and scanning by the first oscillating reflecting mirror. A relay optical system for propagating the light beam bundle, and a second light beam propagating through the relay optical system for scanning a reflected light beam bundle in a second direction intersecting the first direction by being incident and swinging. And a relay optical system in which the first point on the swing center axis of the first swing reflector is set to the swing center axis of the second swing reflector. A light beam scanning device for forming an image on the second point above. 7. An fθ lens for converging a light flux scanned by the second oscillating reflecting mirror onto a processing object, the focus of the fθ lens being coincident with the second point. 7. The light beam scanning device according to claim 6, wherein the fθ lens is arranged as described above.