JPH04325284A - Laser printing apparatus - Google Patents

Abstract

PURPOSE:To use only one polarizing mirror and to reduce the strain of an emitted light image by arranging the polarizing mirror made revolvable in one of X, Y directions and an object lens made movable in the other one of said directions in the light path on an emission side from a liquid crystal mask to a printing surface. CONSTITUTION:A laser oscillator 8, an X-direction polarizing mirror 9, a relay lens 10 and a polygon mirror 11 for scanning a Y-direction are respectively arranged on the incident side of the liquid crystal mask 2 combined with a field lens 1 to form an incident light path 12. The emitting light path 13 of the liquid crystal mask 2 is formed from a polarizing mirror 14 and an object lens 15. The polarizing mirror 14 is revolved, for example, in an X-direction by a motor 16 in the same way as a conventional first scanner mirror to polarize the emitted beam from the liquid crystal mask 2 in the X-direction. The object lens 15 is revolved in the direction right-angled to the revolving direction of the polarizing mirror 14 by a motor 20 through a link mechanism 19.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a laser printing device using a liquid crystal mask, and in particular, an image emitted from the liquid crystal mask is printed in the The present invention relates to a laser printing device that polarizes light in both directions so that the printing position can be changed on the printing surface.

0002

2. Description of the Related Art The above-mentioned conventional laser printing apparatus is constructed as shown in FIG. , a first scanner mirror 5 that polarizes the emitted light in the X direction, a second scanner mirror 6 that polarizes the emitted light in the Y direction, and an objective lens 7 are interposed. The scanner is operated in conjunction with scanner motors 5a and 6a connected to the scanner motors 5a and 6a. The objective lens 7 is a second scanner mirror 6
It is used to correct angular deviation due to Also, between the scanner mirrors 5 and 6, an f-theta lens 7a is provided for correcting angular distortion.
may be necessary.

0003

[Problems to be Solved by the Invention] The conventional laser printing device described above requires two sets of scanner mirrors 5 and 6, an objective lens 7, and an f-theta lens 7a, which requires a large number of parts and also causes distortion. It was difficult to eliminate it completely.

The present invention has been made in consideration of the above-mentioned problems, and has made it possible to simplify the polarization mechanism in the light path on the output side from the liquid crystal mask to the printing surface, and to reduce the distortion of the output light image. The purpose of this invention is to provide a laser printing device.

[0005]

[Means for Solving the Problems] In order to achieve the above object, a laser printing device according to the present invention prints an image emitted from a liquid crystal mask in an output side optical path from an output side of the liquid crystal mask to a printing surface. In a laser printing device that polarizes light in both the direction and the Y direction to change the printing position on the printing surface, a polarizing mirror that is rotatable in one of the X and Y directions is provided in the output side optical path, and a The structure includes an objective lens that is movable in the other direction in the Y direction.

[0006]

[Operation] The image emitted from the liquid crystal mask passes through a polarizing mirror and an objective lens and is irradiated onto the printing surface. At this time, the printing position of this output image on the printing surface is changed by rotating (moving) the polarizing mirror and the objective lens.

[0007]

[Embodiment] An embodiment of the present invention will be explained based on FIGS. 1 to 3. In this embodiment, the same members as those in the conventional example shown in FIG. 4 will be described with the same reference numerals. On the incident side of the liquid crystal mask 2 combined with the field lens 1, an incident side optical path 12 is constituted by a laser oscillator 8, an X-direction polarizing mirror 9, a relay lens 10, and a polygon mirror 11 for Y-direction scanning. Further, the output side optical path 13 of the liquid crystal mask 2 is composed of a polarizing mirror 14 and an objective lens 15. Similarly to the first scanner mirror in the conventional example, the polarizing mirror 14 of the output side optical path 13 is rotated, for example, in the X direction by a rotation motor 16 to polarize the output beam from the liquid crystal mask 2 in the X direction. It looks like this. Further, the objective lens 15 is the polarizing mirror 14
It is rotatably supported in a direction perpendicular to the rotation direction (Y direction). Reference numeral 17 denotes a rotation fulcrum, which is connected to a rotation arm 18 of the rotary arm 18 via a link mechanism 19 to an output shaft of a rotation motor 20.

In the above configuration, predetermined images are displayed on the liquid crystal mask 2 arbitrarily or sequentially by voltage signals applied thereto. In the optical path 12 on the incident side of the liquid crystal mask 2, the laser beam from the laser oscillator 8 is scanned onto the liquid crystal mask 2 by the X-direction polarizing mirror 9 and the polygon mirror 11, and the first image appearing on the liquid crystal mask 2 is is emitted to the output side optical path 13, and this image passes through the polarizing mirror 14 and the objective lens 15 to the print surface 2 of the workpiece etc.
1 and the first printing position a on this printing surface 21.
The first image of the liquid crystal mask 2 is printed on. Next, as shown in FIG. 2, for example, with the objective lens 15 fixed, the polarizing mirror 14 is rotated by a predetermined angle in one direction in the X direction, and a second image is made to appear on the liquid crystal mask 2. By scanning this from
The image is taken when the objective lens 15 is swung to one side in the X direction.
The second image of the liquid crystal mask 2 is printed at a second printing position b in the X direction adjacent to the first printing position a on one side in the X direction. Similarly, by performing the above operation by rotating the polarizing mirror 14 by a predetermined angle in the other direction in the X direction, a third image is printed on the printing surface 21 at the third printing position c in the X direction. On the other hand, as shown in FIG. 3, when the objective lens 15 is rotated by a predetermined angle in one direction in the Y direction from the state where the first image is printed with the polarizing mirror 14 fixed, the fourth image of the liquid crystal mask 2 is rotated. The image is printed at a second printing position d in the Y direction adjacent to one side of the first printing position in the Y direction. Similarly, by rotating the objective lens 15 by a predetermined angle in the other direction in the Y direction and irradiating the image, the fifth image on the liquid crystal mask 2 is projected onto the third image in the Y direction adjacent to the other side in the Y direction of the first printing position. Printed at print position e. In addition to the above-mentioned X and Y directions, by co-moving the polarizing mirror 14 and the objective lens 15, it is possible to
The printing position can also be shifted in the 5° direction. In the above operation, by setting the image appearing on the liquid crystal mask 2 as a part of a certain large image, it is possible to draw a larger image in sections with the images printed at each of the printing positions a to e. In the above embodiment, the X-direction polarizing mirror 9 and the polygon mirror 11 are provided in the incident side optical path 12.
An example of a scanner type is shown in which the incident side optical path 12 is provided with a light source directly facing the liquid crystal mask 2 and with the optical path expanded so that the entire surface of the liquid crystal mask 2 is irradiated with light. Light may be irradiated in one shot. Rotating motors 16 and 20 for operating the polarizing mirror 14 and objective lens 15 in the exit-side optical path 13, the liquid crystal mask 2, and the like are controlled by a control device (not shown). The rotation motors 16 and 20 are pulse motors or A
C servo is used, which allows absolute position control to be performed easily and accurately, and furthermore, the time required for operation is short. Here, since the rotation motors 16 and 20 have limited rotation, a limiter is used to prevent danger. Although the embodiment shown in FIG. 1 shows an example in which the objective lens 15 is rotated via a link mechanism, the means for rotating the objective lens 15 is not limited to the link mechanism, and may of course be rotated via a belt. It may also be configured to move. Further, in the above embodiment, an example was shown in which the objective lens 15 was rotated with respect to the optical axis, but the objective lens 15 may be moved in parallel in a direction perpendicular to the optical axis.

[0009]

According to the present invention, the polarization mechanism in the output side optical path 13 from the liquid crystal mask 2 to the printing surface 21 can be replaced with two polarizing mirrors, which were conventionally required, into one. can be simplified. Furthermore, by combining one polarizing mirror and one objective lens, the distortion of the output light image is reduced, and the f-theta lens that was conventionally required can be dispensed with.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an optical path diagram on the output side when the polarizing mirror is rotated.

FIG. 3 is an exit side optical path diagram with the objective lens rotated.

FIG. 4 is a schematic configuration explanatory diagram showing a conventional example.

[Explanation of symbols]

1 field lens, 2 liquid crystal mask, 13
Output side optical path, 14 polarizing mirror, 15 objective lens, 21 printing surface.

Claims (1)

[Claims] [Claim 1] The image emitted from the liquid crystal mask is polarized in both the X direction and the Y direction in the output side optical path from the output side of the liquid crystal mask to the printing surface, so that the printing position can be changed on the printing surface. In a laser printing device, in the output side optical path,
A polarizing mirror that can be rotated in one of the X and Y directions,
A laser printing device characterized by being provided with an objective lens movable in the other direction in the Y direction.