JPH04190264A - Laser write device - Google Patents

Abstract

PURPOSE:To reduce vibration effect of a polygon mirror device and realize the formation of a quality image having little scanning unevenness, by fixing a laser radiation portion to a base at one place at least, and supporting another at least one place through a vibration absorbing member. CONSTITUTION:A laser radiation element 115, collimator lenses 116 are assembled at a laser radiation portion 11, and laser rays emitted from the element 115 are radiated as a parallel light flux. A radiation portion 11 is fixed at a fitting stand 171 by means of a screw 32, and positioning is also conducted. And a vibration proof rubber 31 is also pinched, and tightened up by means of the screw 32. As a result, the portion 11 is positioned against a base 17 by means of the screw 32, and at the same time supported at the base 17 by means of the rubber 31, and accordingly, a two-level support condition is realized by support of an arm plate 111. As a polygon mirror device is fitted directly to the base 17, its vibration is transmitted to the portion 11 through the plate 11 and the rubber 31, and amplitude is reduced, and unevenness of laser ray scanning is kept little.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser writing device for writing an image on a photoreceptor using a laser beam, in which the attachment of a laser emitting section is improved.

[Background of the invention]

A laser writing device typically includes a laser emitting section 11. as shown in FIG. 1st. second cylindrical lens 12.14,
It is composed of a polygon mirror device 13, an fθ lens I5, a reflection mirror 16, etc., and is integrated into a highly rigid base 17. The laser beam emitted from the laser emitting unit 11 passes through the first cylindrical lens 12, is swung left and right by the polygon mirror device 13 rotating at high speed, passes through the second cylindrical lens 14, the fθ lens 15, and then passes through the reflection mirror 16. A latent image 19 of the image is formed on the surface of the rotating photoreceptor drum 18. The latent image on the photoconductor is developed with toner and transferred to transfer paper.
It is well known that image formation is completed by fixing.

As mentioned above, the laser writing device is an important device for image formation.In particular, the polygon mirror device rotates at high speed as mentioned above, so the polygon mirror device should be designed so that the vibrations generated by this will have little effect on image formation. Measures have been taken such as attaching the device to a base by floating it with vibration-absorbing rubber or the like, or increasing the overall strength to make it less likely to vibrate.

[Problem to be solved by the invention] Since the polygon mirror device rotates at high speed as described above,
When the resulting vibration vibrates the laser writing device, uneven scanning of the laser beam occurs, resulting in a striped pattern of shading in the image written on the photoreceptor drum. This striped pattern is commonly referred to as pitch unevenness, and for example, in experiments conducted by the present inventor, a polygon mirror device with 16. OOO
When rotated at rpm, there was a pitch unevenness of about 0.5 mm+. When the polygon mirror device rotates at high speed as described above, and the vibration generated thereby causes the laser emitting part to vibrate, uneven scanning of the laser beam is caused by the vibrations of other cylindrical lenses, polygon mirror devices, f-theta lenses, and reflection mirrors. The impact will be greater. This is thought to be because the distance from the image position on the photoreceptor to the laser emitting section is greater than in other units, so even a slight vibration is magnified on the photoreceptor.

In addition, if the polygon mirror device is suspended on a base using anti-vibration rubber or the like as described above, the vibration generated by the polygon mirror device will be difficult to transmit to the base, but the amplitude of the polygon mirror device itself will be increased and the scanning speed will be increased. The unevenness has grown.

To summarize the situation in which uneven scanning of the laser beam occurs in a laser writing device due to vibration caused by the high-speed rotation of the polygon mirror device mentioned above, uneven scanning of the laser beam occurs when the laser emitting part is directly attached to the base of the laser writing device. Another problem is that if the polygon mirror device, which is the source of vibration, is raised above the base using anti-vibration rubber or the like, the scanning unevenness of the laser beam will become more uneven.

The present invention has been made to solve the above problems, and the present invention makes it possible to attach the laser emitting part to the laser writing device with less influence of vibration of the polygon mirror device, thereby achieving high scanning height with less uneven scanning. The object of the present invention is to provide a laser writing device that can easily form high-quality images, has a simple structure, is highly reliable, and is inexpensive.

[Means to solve the problem]

The above object provides a laser writing device having at least a laser emitting section and a polygon mirror device, wherein the laser emitting section is attached to at least one polygon mirror device on a base of the laser writing device.
This is achieved by a laser writing device that is fixed at one location and supported at least one other location by the base via a vibration absorbing member.

〔Example〕

An embodiment of the laser writing device of the present invention is shown in FIG.

This figure is a side view (partially a vertical cross-sectional view) of the main part of the laser emitting section to which the present invention is applied, which is attached to the laser writing device.

Inside the lens barrel of the laser emitting unit 11, a laser emitting element 1 is located at the deepest position.
15 is attached, and a collimator lens 116 is installed on the left side of the laser emitting element 115 at a predetermined interval.The collimator lens 116 is held down by a ring, and the laser light emitted from the laser emitting element 115 is directed in the direction of the arrow. It is emitted as a parallel beam of light.

The base 17 of the laser writing device is attached to the laser emitting unit 11 by arm plates 111 protruding from both sides for fixing the base 17 to the base 171.
The laser emitting unit 11 is also positioned. At this time, the vibration isolating rubber 31, which is slightly thicker than the gap between the mounting base 171 and the laser emitting part 11, is also sandwiched between the two, and the positioning screw 32 is tightened to the extent that the vibration isolating rubber 31 is offset by 0.2 to 0.8 mm. Because of this configuration, the laser emitting unit 11 is connected to the base 1 of the laser writing device.
At the same time, the laser emitting part 11 is moved to the base 1 by the anti-vibration rubber 31.
7, and is therefore supported on both sides with support by the arm plate 111. Since the polygon mirror device is attached directly to the base 17 of the laser writing device,
The vibration of the polygon mirror device is caused by the laser emitting unit 11 and the arm plate 1.
11 and the vibration isolating rubber 31, the amplitude is reduced compared to the state where the vibration is supported on a flat surface, and the scanning unevenness of the laser beam is suppressed to a small level.

FIG. 2 is a side view (partially longitudinal sectional view) of another embodiment.

In this embodiment, the base 17 of the laser writing device is attached to the base 1.
The position of the arm plate 111 of the laser emitting unit 11 for fixing the laser emitting unit 11 to the 71 is opposite to that shown in FIG. It is fixed by the pin 32, and its function and effect are the same as those explained in Section 1A, so a description thereof will be omitted.

In addition, in the above explanation, vibration isolating rubber is used as a member for absorbing vibrations, but it is not limited to vibration isolating rubber, and metal springs or air springs may be used with appropriate shape, size, spring constant, etc. If selected, it can be used as a vibration absorbing member.

〔Effect of the invention〕

According to the present invention, it is possible to attach the laser emitting part to the laser writing device with less influence of vibration of the polygon mirror device, and thereby it is possible to easily form a high-quality image with less scanning unevenness, and the structure is also simple. Now, a highly reliable and low cost laser writing device has been provided.

[Brief explanation of drawings]

FIG. 1 is a side view (partially a vertical sectional view) showing the main parts of the laser emitting unit to which the present invention is attached to the laser writing device.
. FIG. 2 is a side view (partially longitudinal sectional view) of another embodiment. FIG. 3 is a perspective view of a conventional example. 11... Laser emitting unit 111... Arm plate 13... Polygon mirror device 17... Base 171... Mounting is on stand 3I... Anti-vibration rubber 32... Positioning screw

Claims (1)

[Scope of Claims] A laser writing device having at least a laser emitting section and a polygon mirror device, wherein the laser emitting section is fixed to a base of the laser writing device at least at one place, and at least another one absorbs vibrations. A laser writing device characterized in that the laser writing device is supported by the base via a member that supports the base.