JPH09187986A - Optical device for electronic photographic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of an image by effectively restraining vibration to be generated by rotation of a polygon scanner motor from being transferred to a reflex mirror and reducing irregular pitch of laser beam irradiation on an image carrying body. SOLUTION: There are provided a polygon mirror 12 to be rotated by a scanner motor 12A, an optical system 13 which polarizes laser beam to be scanned by the polygon mirror 12 so as to apply it on an image carrying body and form a predetermined electrostatic latent image on the image carrying body, and a case body 11 for holding these members. The scanner motor 12A is mounted in the case body 11 through a vibration preventing member 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device for an electrophotographic system, and more particularly to an optical device for an electrophotographic system installed in a laser beam printer, a facsimile machine, a copying machine or the like.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example. In the conventional example shown in FIG. 3, a laser unit 51 that emits a laser beam, a polygon mirror 52 that reflects the laser beam, and a polygon scanner motor 5 that rotates the polygon mirror 52.
3, lenses 54 and 55 for converging the laser light reflected and scanned by the polygon mirror 52, and a folding mirror 56 that folds the laser light back to irradiate the drum-shaped photosensitive member with the laser light. Reference numeral 60 indicates a case body that houses these parts. Reference numeral 53A indicates a motor fixing plate for fixing the polygon scanner motor 53.

In the conventional example shown in FIG. 3, the polygon mirror 52 is rotated by the rotation of the polygon scanner motor 53, the laser light emitted from the laser unit 51 is reflected by the polygon mirror 52, and the lenses 54 and 5 are used.
After passing through 5 and being reflected by the folding mirror 56, the drum-shaped photosensitive member is irradiated with the data, thereby writing data.

[0004]

However, in the above-described conventional example, the vibration generated by the rotation of the polygon scanner motor 53 causes the folding mirror 56 to vibrate subtly via the case body 60. .

In such a case, the laser light strikes a position of the drum-shaped photosensitive member which is deviated from a predetermined scanning position, and as a result, a pitch unevenness corresponding to one round of the polygon motor is generated on the printed image, which is large depending on the pattern. There was the inconvenience of image distortion.

[0006]

It is an object of the present invention to improve the disadvantages of the conventional example, particularly to effectively suppress the transmission of the vibration caused by the rotation of the polygon scanner motor to the folding mirror, and the above-mentioned conventional example. It is an object of the present invention to provide an optical device for an electrophotographic system in which the unevenness in the pitch of the laser beam irradiation on the image-image carrier, which has occurred in 1), is reduced, and thereby the quality of the image is improved.

[0007]

In order to achieve the above object, in the invention according to the first aspect, a polygon mirror rotated by a scanner motor and a laser beam scanned by the polygon mirror are polarized to carry an image. An optical system for irradiating a body to form a predetermined electrostatic latent image on the image carrier, and an optical device for an electrophotographic system including a case main body holding each of these parts, in which the scanner motor described above is used. The case body is equipped with a vibration-proof member.

Therefore, in the invention according to the first aspect, the case main body is provided with the vibration isolating member, and the scanner motor is attached to the vibration isolating member. The vibration of the motor is effectively absorbed by the vibration damping member. Therefore, the vibration generated with the rotation of the scanner motor is suppressed by the anti-vibration member attached to the scanner motor, and the vibration propagating to the folding mirror is significantly and surely reduced.

According to the second aspect of the present invention, a polygon mirror rotated by a scanner motor and a laser beam scanned by the polygon mirror are polarized and irradiated onto an image carrier, and a predetermined amount is projected on the image carrier. In an optical device for an electrophotographic system, which includes an optical system for forming an electrostatic latent image and a case body for holding each of these parts, the scanner motor described above is connected to the case body via a motor holding plate and a vibration isolation member. It is equipped with.

Therefore, according to the second aspect of the invention, since the vibration isolating member 21 is sandwiched between the motor holding plate 22 and the case body 1A while the scanner motor 12A is attached, the motor holding member is held. The vibration of the scanner motor 12A directly transmitted to the plate 22 is effectively absorbed by the vibration isolator 21 through the entire surface thereof. That is, the vibration generated along with the rotation of the scanner motor 12A is suppressed by the antivibration member 21 attached to the scanner motor 12A, and the vibration propagating to the folding mirror 16 is significantly and surely reduced.

According to a third aspect of the present invention, the above-mentioned vibration isolating member is formed in a rectangular shape.

Also in this case, the above-mentioned claim 1 or 2
In addition to functioning in the same manner as the described invention, it is possible to effectively avoid the resonance point, and thus it is possible to effectively suppress an increase in the vibration level.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described with reference to FIG.

In FIG. 1, reference numeral 1 indicates a polygon scanner unit. This polygon scanner unit 1
A laser beam output section (not shown) formed in the same manner as the conventional example described above, a polygon mirror 12 that reflects the laser beam output from the laser beam output section while rotating, and a polygon mirror 12 that scans the laser beam. An optical system 13 that polarizes a laser beam to irradiate it onto a drum-shaped photoconductor (not shown) as an image carrier to form a predetermined electrostatic latent image on the drum-shaped photoconductor, and stores these parts. The case main body 1A is provided. Reference numeral 1a indicates a window portion for irradiating the drum-shaped photosensitive member (not shown) with laser light.

The optical system 13 includes a scanner motor 12A for rotating the polygon mirror 12 and the polygon mirror 1.
Lenses 14 and 15 for converging the laser beam reflected and scanned by 2 and a folding mirror 16 for folding the laser beam to irradiate the laser beam onto a drum-shaped photosensitive member (not shown) are provided. The folding mirror 16 is mounted on the case body 1A in a fixed or bonded state.

Reference numeral 21 denotes a thick plate vibration damping member. The anti-vibration member 21 has a function of preventing minute vibrations of the scanner motor 12A from being transmitted to the folding mirror 16 via the case body 1A. In FIG. 1, the scanner motor 12A is first mounted on the motor holding plate 22, and the motor holding plate 22 is attached to the case body 1A via the above-described vibration isolating member 21.

FIG. 2 shows a vibration isolating member 21 and a motor holding plate 22 which are respectively formed in a rectangular shape. By forming the motor holding plate 22 and the vibration isolation member 21 into a rectangular shape, the above-described scanner motor 12A
It is possible to shift the resonance point of the vibration output from, and thereby suppress the increase of the vibration due to the resonance.

Further, in FIG. 2, the motor holding plate 22 has elongated holes 22a, 22 for attachment at its four corners.
b, 22c and 22d are provided. Then, in order to avoid the elongated holes 22a, 22b, 22c, 22d, the above-described vibration-proof member 21 is used in a state where its four corners are cut off, whereby the motor holding plate 22 is cased at the four corners. It is designed to be bolted to the main body 1A.

Here, among the elongated holes 22a to 22d, the elongated holes 22a and 22b on one side (the lower end side in FIG. 2) are formed in an elliptical shape having a long axis in the left-right direction in FIG. ing.
In addition, the elongated holes 22c, 22 on the other side (upper end side in FIG. 2)
d is formed in an elliptical shape in which the major axis is arranged in a V shape. As a result, the mounting positions of the scanner motor 12A and the polygon mirror 12 on the case body 1A can be adjusted freely.

When mounting the scanner motor 12A, the vibration-proof member 21 is attached to the motor holding plate 22.
It is sandwiched between the case body 1A and the case body 1A, and the vibration of the scanner motor 12A directly transmitted to the motor holding plate 22 is effectively absorbed by the vibration isolator 21 through the entire surface thereof.

Therefore, in the above embodiment, the vibration generated along with the rotation of the scanner motor 12A is suppressed by the antivibration member 21 attached to the scanner motor 12A, so that the vibration propagating to the folding mirror 16 is greatly increased. And reliably reduced.

In the above embodiment, the case where the anti-vibration member 21 is sandwiched between the motor holding plate 22 and the case main body 1A has been described as an example, but the scanner motor 12A is fixed via a pedestal or the like. Alternatively, the vibration-proof member 21 may be directly attached.

In this way, the scanner motor 12A
Is not directly supported by the case body 1A, so that the vibration energy propagating to the case body 1A can be more effectively absorbed.

[0024]

Since the present invention is constructed and functions as described above, according to this, the vibration of the scanner motor can be effectively absorbed by the action of the vibration isolating member.
The component propagating to the folding mirror and vibrating the folding mirror can be effectively reduced as compared with the conventional example, and therefore unevenness in irradiation pitch due to the laser light on the drum-shaped photoconductor due to the vibration of the folding mirror is reduced. be able to.

As a result, the misalignment at the time of writing is reduced and the disturbance of printing is eliminated, and at this point, the image can be maintained at a high quality, and it is possible to improve the reliability of the entire apparatus, which is an excellent electronic device that has never been used. An optical device for a photographic system can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a vibration isolation member and a motor holding plate disclosed in FIG. 1, and FIG. 2 (a) is a plan view,
2B shows a right side view of FIG. 1A, and FIG.
Shows the bottom view of FIG.

FIG. 3 is a partially omitted plan view showing a conventional example.

[Explanation of symbols]

 11 Case Main Body 12 Polygon Mirror 12A Scanner Motor 13 Optical System 21 Anti-Vibration Member 22 Motor Holding Plate

Claims (3)

[Claims] 1. A polygon mirror rotatably driven by a scanner motor, and a laser beam scanned by the polygon mirror is polarized and irradiated onto an image carrier to form a predetermined electrostatic latent image on the image carrier. An optical device for an electrophotographic system, comprising: an optical system for controlling an optical system; and a case body holding each of these parts, wherein the scanner motor is mounted on the case body via a vibration isolating member. Optical device. 2. A polygon mirror rotatably driven by a scanner motor, and a laser beam scanned by the polygon mirror is polarized and irradiated onto an image carrier to form a predetermined electrostatic latent image on the image carrier. In the optical device for an electrophotographic system, which includes an optical system for holding and each of these portions, a scanner motor is provided in the case body via a motor holding plate and a vibration isolating member. Optical device for electrophotographic system. 3. The optical device for an electrophotographic system according to claim 1, wherein the vibration isolating member is formed in a rectangular shape.