JPH05150175A - Scanning drawing device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an optical system of a drawing device that enables focus adjustment for drawing objects having different thicknesses while maintaining a telecentric state without moving the table in the optical axis direction. [Configuration] Light source 11 that emits a light flux for drawing, and light source 11
Deflection unit 12 for deflecting and scanning the light beam from the scanning unit, a telecentric scanning lens 14 for converging the light beam from the deflection unit 12 on the object to be drawn, and a scanning lens for moving the scanning lens 14 in the optical axis direction to adjust the focus. Drive means 15,
An optical path changer that is provided between the deflecting unit 12 and the scanning lens 14 and changes the optical path of the light beam from the deflecting unit 12 while maintaining the telecentric state of the scanning lens 14 when focus adjustment is performed by moving the scanning lens 14. Means 13
And a table 16 provided at a predetermined distance from the deflecting means 12 and supporting the drawing target.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning drawing apparatus for drawing an image on a drawing object on a table.

[0002]

2. Description of the Related Art Some scanning drawing apparatuses use a telecentric lens for drawing a precise image on a drawing object. An example of such a scanning drawing device is shown in FIG. In this scanning drawing apparatus, the scanning lens 41 is a telecentric lens. The light beam 1 incident on the scanning lens 41 is scanned in the main scanning direction of arrow A by a polygon mirror or the like. The light flux 1 that has entered the scanning lens 41 is emitted perpendicularly to the drawing target on the table 42 and scans this drawing target. As a result, an image is drawn on the drawing object on the table 42.

[0003]

In the scanning drawing apparatus, the drawing object may range from a thin object such as a film to a thick object such as glass. When the thickness of the drawing object changes, the distance between the scanning lens and the drawing object changes, so that the focus adjustment of the light flux is necessary.

In such a case, as shown in FIG.
By moving the scanning lens 41 in the optical axis direction, that is, in the direction of arrow B or in the opposite direction, it is possible to converge the light flux and focus it. However, when the scanning lens 41 is moved in the optical axis direction to adjust the focus, the scanning lens 41
The position of the entrance pupil of the scanning lens 41 changes with respect to the light beam 1 traveling toward, and the telecentric state of the scanning lens 41 cannot be maintained.

Therefore, in order to prevent such a situation, in the conventional scanning drawing apparatus, the table is moved in the optical axis direction to adjust the focus. However, when the drawing object becomes large and the table becomes large and the weight of the table becomes heavy, there is a disadvantage that a device for driving the table becomes large.

The object of the present invention is to eliminate the above drawbacks and to provide a scanning drawing apparatus capable of maintaining a telecentric state when the thickness of an object to be drawn changes and adjusting the focus with the table fixed. To provide.

[0007]

In order to achieve the object of the present invention, a light source which emits a light flux for drawing, a deflecting means for deflecting and scanning the light flux from the light source, and a light flux from the deflecting means are to be drawn. It is provided between a telecentric scanning lens that converges on an object, a scanning lens driving unit that moves the scanning lens in the optical axis direction to adjust the focus, a deflection unit and the scanning lens, and the focus adjustment is performed by moving the scanning lens. When performed, the optical path changing means changes the optical path of the light beam from the deflecting means while maintaining the telecentric state of the scanning lens, and the table provided at a predetermined distance from the deflecting means and supporting the drawing target.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

[0009]

[Embodiment 1] FIG. 1 shows Embodiment 1 of a scanning drawing apparatus according to the present invention. This scanning drawing device
The light source 11, the deflecting unit 12, the optical path changing unit 13, the scanning lens 14, the scanning lens driving unit 15, and the table 16 are provided.

The light source 11 includes a scanning laser 11A for emitting a drawing light beam, a converging lens 11B for converging a laser light beam from the scanning laser 11A, and a converging lens 11A.
A / O modulator 11C for modulating the light flux converged by B
And a collimator lens 11D that converts the light flux from the A / O modulator 11C into a parallel light flux.

The deflecting means 12 is rotated by a motor 12A which rotates in a fixed direction, and a polygon mirror 12B which is rotated by the motor 12A to scan and deflect a parallel light beam from the light source 11.
It has and.

The optical path changing means 13 is a plane parallel plate 13A.
And a flat plate drive unit 13B.

The plane-parallel plate 13A is made of transparent plate-shaped glass, plastic, or the like having a predetermined thickness, and changes the optical path of the light flux by moving the incident light flux in parallel by refraction according to the incident angle.

The plane plate drive unit 13B moves the plane parallel plate 13A in the main scanning direction indicated by the arrow A in response to a drive signal from the scanning lens drive means 15 to move the plane light parallel to the optical path of the light beam from the deflection means 12. Insert. As a result, the light flux from the deflecting means 12 is translated by the parallel plane plate 13A by refraction according to the incident angle, and the optical path of the light flux is changed. Further, the plane parallel plate 13A is moved in the opposite direction to remove the plane parallel plate 13A from the optical path.

The scanning lens 14 is a lens that is telecentric with respect to the table 16 side, and has the optical path changing means 1
The light fluxes from No. 3 are converged on the drawing target on the table 16.

The scanning lens driving means 15 comprises a scanning lens driving section 15A and a detecting section 15B.

The scanning lens driver 15A includes a detector 15B.
The scanning lens 14 is moved in the optical axis direction, that is, the arrow B or the opposite direction by the detection signal from. Further, the scanning lens drive unit 15A sends a drive signal indicating this movement to the plane plate drive unit 13B of the optical path changing unit 13.

The detection unit 15B detects whether or not the light beam applied to the drawing target on the table 16 is in focus, and generates a detection signal indicating the detection result. Then, this detection signal is sent to the scanning lens driving unit 15A.

The table 16 holds objects to be drawn having different thicknesses, and is arranged at a predetermined distance from the polygon mirror 12B.

Next, the operation of the first embodiment will be described.

First, the case of drawing an image on a drawing object having a large thickness will be described. As shown in FIG. 2, when the drawing object 101 having a large thickness is placed on the table 16, the plane-parallel plate 13A moves in the main scanning direction indicated by the arrow A by the plane-plate driving unit 13B, and the solid line As indicated by
It is out of the light path. Therefore, the light flux 1 from the light source 11 deflected and scanned by the deflecting means 12 is directly
It enters the scanning lens 14.

At this time, the scanning lens 14 is mounted on the table 1
The drawing object 6 is in a telecentric state with respect to the drawing object, and the light flux 1 is converged by the scanning lens 14 and vertically incident on the drawing object 101.

Next, when the drawing object on the table 16 of FIG. 2 is replaced with a thin object, the detecting unit 15B
It is detected that the light flux applied to the drawing object is out of focus, and a detection signal indicating the detection result is sent to the scanning lens driving unit 15A. Upon receiving this detection signal, the scanning lens driving unit 15A moves the scanning lens 14 in the direction perpendicular to the table 16 and, at the same time, sends a driving signal indicating this movement to the flat plate driving unit 13B.

Upon receiving this drive signal, the plane plate drive unit 13B moves the plane parallel plate 13A in the direction opposite to the main scanning direction indicated by the arrow A. By this movement, the plane parallel plate 13
A is inserted in the optical path, as shown by the chain line in FIG. Therefore, the light flux 1 is refracted by the plane-parallel plate 13A to change its optical path and enters the scanning lens 14 as shown by the chain line in FIG.

At this time, the scanning lens 14 is moving in the direction of the optical axis of arrow B, and when the light beam applied to the object to be drawn is in focus, the detecting section 15B detects this state and
A detection signal indicating the in-focus state is sent to the scanning lens driving unit 15A. The scanning lens driving unit 15A stops the movement of the scanning lens 14 based on this detection signal. As a result, the in-focus state with respect to the thin drawing target object is maintained.

At this time, the light beam 1 from the plane-parallel plate 13A shown by the chain line in FIG. 2 enters the scanning lens 14 in the same state as when the thick drawing object is scanned. Therefore, the telecentric state of the scanning lens 14 is maintained, and it becomes possible to perform drawing on a thin drawing object.

In this way, when the drawing object is replaced, the first embodiment changes the optical path of the light flux using the plane parallel plate 13A. Thereby, the focus can be adjusted while the telecentric state is maintained and the table 16 is fixed. In the first embodiment, the drawing object has two thicknesses. However, when an object having three or more different thicknesses is the drawing object, the parallel flats having different thicknesses are used for the respective drawing objects. A telecentric state can be maintained by using a face plate or a plane-parallel plate having a different refractive index.

[0028]

[Embodiment 2] FIG. 3 shows Embodiment 2 of the scanning drawing apparatus according to the present invention.

The second embodiment is the optical path changing means of FIG.
Wedge-shaped prisms 21A and 21B and a prism drive unit 21C are used.

The prisms 21A and 21B are made of wedge-shaped glass, as shown in FIG.
It is inserted in the optical path of the light beam from the deflecting means 12. Further, the exit end surface 202, which is the slope of the prism 21A, is arranged to face the entrance end surface 203, which is the slope of the prism 21B. Then, the prisms 21A and 21B are relatively moved by the prism driving unit 21C.
That is, when the prism 21A moves in the tilt direction indicated by the arrow C, the prism 21B moves the exit end surface 202 of the prism 21A in the direction opposite to the arrow C. Also,
The prisms 21A and 21B move in opposite directions.

The prism driving section 21C receives the driving signal from the scanning lens driving section 15A, and the prisms 21A and 2C.
1B is moved in the direction of the arrow C or in the opposite direction.

In the second embodiment, when the thickness of the object to be drawn becomes thin, the surface distance a from the entrance end face 201 of the prism 21A to the exit end face 204 of the prism 21B is increased. On the contrary, when the thickness becomes thicker, the inter-face distance a is made smaller and the optical path of the light flux is changed. Further, the surface distance a can be continuously changed, and the optical path of the light flux 1 can be continuously changed according to the thickness of the drawing target.

As described above, in the second embodiment, when the thickness of the drawing target is changed, the two wedge prisms 21A and 21A are formed.
B changes the optical path of the light beam. Thereby, the focus can be adjusted while the telecentric state is maintained and the table 16 is fixed. Example 2
Are two prisms 21A and 21B as compared with the first embodiment.
Since the optical path of the light flux can be continuously changed by sliding, it is possible to deal with a plurality of drawing objects having different thicknesses without exchanging the prism.

[0034]

[Third Embodiment] FIG. 5 shows a third embodiment of the scanning drawing apparatus according to the present invention.

The third embodiment is the optical path changing means of FIG.
The mirror unit 31 including the mirrors 32 to 35 and the mirror driving unit 36 are included.

The mirrors 32 and 35 are arranged in a V-shape with the mirror surfaces 32A and 35A for reflecting the light flux on the outside. The mirrors 33 and 34 have a mirror surface 33A.
And 34A inside, and arranged in a V shape.
Further, the respective mirrors 32 to 35 are arranged so that the mirror surface 32A faces the mirror surface 33A and the mirror surface 34A faces the mirror surface 35A.

The mirror drive unit 36 receives the drive signal from the scanning lens drive unit 15A of the scanning lens 14 to drive the mirror 3
3, 34 are moved in the main scanning direction indicated by arrow A or in the opposite direction.

According to the third embodiment, when the thickness of the object to be drawn is small, the mirror driving unit 36 causes the mirror 3 to move.
3, 34 move in the main scanning direction of arrow A. Further, when the drawing target is thick, the mirrors 33 and 34 move in opposite directions. Thereby, the optical path of the light flux 1 is continuously changed according to the thickness of the drawing target.

In this way, when the drawing object is replaced, the third embodiment moves the mirrors 33 and 34 to change the optical path of the light beam. Thereby, the telecentric state is maintained, and the focus can be adjusted with the table 16 fixed. Further, in the third embodiment, the mirror 33,
Since 34 is moved in the direction of arrow A or in the opposite direction, the optical path of the light flux can be largely changed, and it is possible to deal with an object to be drawn having a thickness greatly different from that of the second embodiment.

[0040]

As described above, according to the present invention, when the thickness of the replaced drawing object changes, the telecentric state is maintained and the focus can be adjusted with the table fixed. effective.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the plane-parallel plate of the embodiment of FIG.

FIG. 3 is a diagram for explaining a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the wedge-shaped prism of the embodiment of FIG.

FIG. 5 is a diagram for explaining a third embodiment of the present invention.

FIG. 6 is a diagram for explaining a conventional scanning drawing apparatus.

[Explanation of symbols]

 11 light source 12 deflecting means 13 optical path changing means 14 scanning lens 15 scanning lens driving means 16 table

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[Procedure amendment]

[Submission date] January 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In order to achieve the object of the present invention, a light source which emits a light flux for drawing, a deflecting means for deflecting and scanning the light flux from the light source, and a light flux from the deflecting means are to be drawn. It is provided between a telecentric scanning lens that converges on an object, a scanning lens driving unit that moves the scanning lens in the optical axis direction to adjust the focus, and a deflecting unit and the scanning lens. When performed, the optical path changing means for changing the optical path of the light beam from the deflecting means while maintaining the telecentric state of the scanning lens, and the object supporting means provided at a predetermined distance from the deflecting means and supporting the drawing object. ing.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Embodiment 1] FIG. 1 shows Embodiment 1 of a scanning type drawing apparatus according to the present invention. This scanning drawing device
The light source 11, the deflection unit 12, the optical path changing unit 13, the scanning lens 14, the scanning lens driving unit 15, and the table.
(Target object supporting means) 16.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of reference numerals] 11 light source 12 deflecting means 13 optical path changing means 14 scanning lens 15 scanning lens driving means 16 table (object supporting means)

Claims (5)

[Claims] 1. A light source that emits a light beam for drawing, a deflecting unit that deflects and scans the light beam from the light source, a telecentric scanning lens that converges the light beam from the deflecting unit onto an object to be drawn, and the scanning lens. Is provided between the deflecting means and the scanning lens for moving the lens in the optical axis direction to adjust the focus, and when the focus is adjusted by the movement of the scanning lens, the telecentric of the scanning lens A scanning drawing apparatus comprising: an optical path changing unit that changes an optical path of a light beam from the deflecting unit while maintaining a state; and a table that is provided at a predetermined distance from the deflecting unit and supports a drawing target. 2. The optical path changing means includes a plane parallel plate that is removably provided in an optical path between the deflecting means and the scanning lens, and the scanning lens approaches the table for focus adjustment. When moving in the direction, the plane-parallel plate is inserted into the optical path of the light beam from the deflecting means, and when the scanning lens moves in the direction away from the table, the plane-plate driving unit removes the plane-parallel plate from the optical path. The scanning drawing apparatus according to claim 1, further comprising: 3. The optical path changing means closely contacts the slopes of one of the incident end faces so that the inter-face distance between the incident end face and the exit end face can be changed while keeping one incident end face parallel to the other exit end face. And two wedge-shaped prisms that are slidably held, and when the scanning lens moves toward the table for focus adjustment, the inter-surface distance is reduced so that the scanning lens moves toward the table. 2. The scanning drawing apparatus according to claim 1, further comprising a prism driving unit that moves the two wedge-shaped prisms so as to increase the inter-face distance when moving in a direction away from. 4. The optical path changing means includes first, second, third and fourth mirrors for sequentially reflecting the light flux from the deflection changing means to change the optical path of the light flux. The first and fourth mirrors are fixed with their mirror surfaces facing outward and are arranged in a V shape, and the second and third mirrors have their mirror surfaces facing inside and the first and fourth mirrors. A mirror portion that is arranged in a V shape so that the mirror surfaces of the first and second mirrors face each other and the mirror surfaces of the third and fourth mirrors face each other. And when the scanning lens moves toward the table for focus adjustment, the scanning lens moves away from the first and fourth mirrors, and when the scanning lens moves away from the table, the first And the fourth Mi Scanning writing apparatus according to claim 1, further comprising a mirror drive unit for moving the second and third mirrors to approach the over. 5. The scanning drawing apparatus according to claim 1, wherein the light flux passing through said optical path changing means is a parallel light flux.