JPS62187816A - Rotary polygonal mirror device - Google Patents

Abstract

PURPOSE:To easily detect the angle deflection of the shaft of a rotary polygonal mirror and to facilitate balance adjustments at the time of the manufacture of the rotary polygonal mirror device by providing the rotary polygonal mirror adjacently with a columnar mirror coaxial with its rotating shaft. CONSTITUTION:This device has a photodetector which irradiates the columnar mirror 2 of the rotary polygonal mirror device 6 with laser light 9 emitted by a laser light source 8 and photodetects its reflected light to output an electric signal corresponding to the quantity of photodetection and a knife-edge which is arranged in front of the photodetector 10 at right angles to the direction of the reflected light varying with the angle deflection of the shaft of the rotary polygonal mirror device 6 so as to cut off part of the reflected light. Then, a signal processing circuit 12 measures the angle deflection of the shaft of the rotary polygonal mirror device 6 from variation in the output of the photodetector 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application J) The present invention relates to a rotating polygon mirror device, particularly to a rotating polygon mirror device used in a laser beam grille/laser beam scanner or the like.

[Technical Environment J] In recent years, rotating multi-faceted copper bearings are required to rotate at extremely high speeds and with unparalleled precision in order to increase the speed and print quality of laser beam printers, etc.

[Conventional technology]

A conventional rotary polygon furnace apparatus includes a rotary polygon mirror, a drive shaft that drives the rotary polygon mirror in full rotation, and a bearing that fully supports the drive shaft.
It consists of:

Next, a conventional rotating polygon mirror device will be described in detail with reference to all the drawings.

Figure 4 shows the conventional rotating polygon a! An example of soro? FIG.

The rotating polygon mirror device t shown in FIG. 4 includes (b) a drive shaft 3 for rotationally driving the rotating polygon blunt 1 and the rotating polygon flAIWr, a bearing 4 supporting the drive shaft 31r, and a bearing housing portion 5.

FIG. 5 is a schematic diagram showing an example of the scanning section of a conventional rotating multi-faceted steel system [Kanusei-tomo laser beam printer].

8 minutes of scanning of the laser beam printer shown in FIG. [This deflected laser beam is deflected by the rotating polygon mirror L of 7 at a right angle to the rotation axis, and the deflected laser beam 167 is an imaging lens unit) (Fθ lens) 17? The photoreceptor 18 is scanned over a uniformly charged photoreceptor 18 through the
8, an electrostatic latent image is formed on the surface.

The sixth factor is an explanatory diagram illustrating the effects of axial vibration, particularly angular vibration of the rotating polygon mirror device in a laser beam printer.

An angle loss of the shaft of the rotating polygon mirror device 7 shown in FIG. 6 occurs,
If the rotating polygon mirror 1 is small, the laser beam ft, 16 is also taken in a direction perpendicular to the scanning direction, so the imaging lens unit l-
The scanning edge 19, which is imaged on the photoreceptor 18 through the photoreceptor 17t, will be misaligned in the directions 19a and 19b in a direction perpendicular to the scanning direction.

[Problem that the invention seeks to solve]

Does the above-mentioned rotary multi-faceted ffA device t take pictures of rotations when rotated at high speed? Adjustment work to keep it small is difficult because it is difficult to measure the excavation (it is necessary to develop an electrostatic latent image and actually measure the positional deviation in the direction perpendicular to the scanning edge at each position on the scan Morikawa using a full coordinate measuring device). Because it is impossible to eliminate unsteady rotational excavation, it is impossible to eliminate unsteady rotational excavation.
Run'! f. There was a flaw in that the ridges were misaligned in the direction perpendicular to the scanning line, resulting in a total deterioration of print quality.

[Means for Solving the Problems J] The rotating polygonal steel G7IC of the present invention comprises a rotating polygon mirror, a drive shaft for rotationally driving the rotating polygon mirror, a bearing for supporting the drive shaft, and a rotating polygon mirror for rotating the polygon mirror. It is configured to include a cylindrical mirror located adjacent to the drive shaft and coaxial with the drive shaft.

[Example j] Next, practical examples of the present invention will be described in detail with reference to all the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention. The rotating polygon mirror shown in FIG. A cylindrical shaft 2 located adjacent to the drive shaft 3 and coaxial with it? It is included in the bottom.

FIG. 2 is a schematic diagram showing the construction of a shaft angle measurement device for measuring all the shaft angles of the rotary polygon mirror device according to the invention.

The angular deflection measuring device of the shaft shown in FIG. 2 irradiates the cylindrical mirror 2 of the rotating polygon mirror device 6 of the present invention with nine laser beams emitted from a laser light source 8, and receives the reflected light to obtain the amount of light received. The light receiver 10 outputs all nine electrical signals in accordance with the direction of the reflected light, which changes direction depending on the angular deflection of the axis of the uninvented rotating polygon mirror device 6, and a part of the reflected light in the perpendicular direction? FI cutting device 1
The angle of the axis of the rotating polygon mirror device 6 of the present invention can be determined from the change in the output of the light receiver 10, which is disposed on the front surface of the rotating polygon mirror device 6. The system includes a signal processing circuit 12 for measurement.

Finally, the uninvented rotating polygon mirror device 1li shown in FIG.
1. By using the axis angular runout measuring device t shown in FIG. 2, it is possible to measure all the angles of the axis without deteriorating print quality when used in a laser beam printer or the like.

FIG. 3 is a schematic configuration diagram showing an example of the scanning part of a laser beam 1 linter that includes the uninvented rotating polygon ψ device shown in FIG. 1 and the axis angle measuring device shown in FIG. 2. .

The scanning part of the laser beam printer shown in FIG.
An uninvented rotating polygon mirror device 6 that scans the wound, an imaging lens unit 17° that forms an image of the laser beam 16 scanned by the wound on a photoreceptor 18, a laser light source 14, and a rotating polygon mirror device 6. A deflector 15 capable of deflecting the laser beam 16 at a minute angle to the rotation axis of the rotating polygon mirror 1 is placed in the optical path between the rotating polygon mirror 1
A laser ft and source 8 that rotates 80 degrees and irradiates a laser beam 9 to a fixed position cylindrical mirror 2 receive all of the laser beam 9 reflected by the cylindrical mirror 2 and output electricity 1g according to the amount of light received. The angle of the axis of the optical receiver 10 and the rotary multifaceted f# device 6 is adjusted.I) A device is installed in front of the optical receiver 10 to block part of the reflected light in a direction perpendicular to the changing direction of the reflected light. A signal processing circuit 12 that measures the angular deflection of the axis of the rotating polygon mirror device ll16 based on the knife error 5-"l 1 (not shown) and changes in the output of the light receiver 10, and a signal from the signal processing circuit 12. Depending on the angle of the laser beam 16 irradiated onto the rotating polygon device ft6, the angle of the laser beam 16 irradiated onto the rotating polygon device ft6 can be adjusted to compensate for the deviation of the scanning line 19 on the sensitive element 18 due to the angle of the axis of the rotating polygon device 6. 15 and a driving device m1l13.

〔Effect of the invention〕

The image rotation polygon fj# device of the present invention is provided with a cylindrical mirror placed adjacent to a rotating polygon mirror and coaxial with the rotation axis, and a laser beam is irradiated onto this cylindrical mirror and the source of the reflection is photographed. By detecting the angle Kffi of the axis of the rotating polygon mirror, it is possible to easily detect the angle Kffi of the axis of the rotating polygon mirror, making it easier to adjust the balance when manufacturing the rotating polygon mirror device. make use of,
In the case of a laser beam printer sound guide maFL, it is possible to completely correct the angle of the laser beam incident on the rotating polygon mirror device of the present invention by using the angular vibration signal sound of the axis to correct the deviation of the scanning line on the photoreceptor. It can be seen that the printing quality can be significantly improved.

[Brief explanation of drawings]

Is Figure 1 one of the strengths of the present invention? Figure 2 is a schematic configuration diagram showing an example of the use of the rotating polygon mirror device shown in Figure 14, and Figure 3 South is a laser beam printer including the angular deflection measurement device of the shaft shown in Figure 2. 4 is a cross-sectional view showing an example of a conventional rotating polygon mirror device, and FIG. 5 is a laser beam printer using one conventional rotating polygon mirror device shown in FIG. 4. An example of the scanning part of ? The schematic configuration diagram shown, and the sixth factor, are explanatory diagrams illustrating all the effects of axial runout of a rotating polygon mirror device in a laser beam printer. DESCRIPTION OF SYMBOLS 1... Rotating polygon mirror, 2... Cylindrical mirror, 3... Drive shaft, 4... Bearing, 5... Bearing housing, 6, 7...
・Rotating polygon mirror device, 8, 14...Laser light source, 10・
. . . Light receiver, 12 . . . 1 set of signal processing 13. . M moving filter, 15 . . . Deflector, 17 . . . Imaging lens unit, 18 . . . Photoreceptor. Foil/Picture foil Z diagram

Claims (1)

[Claims] The present invention is characterized in that it includes a rotating polygon mirror, a drive shaft that rotationally drives the rotating polygon mirror, a bearing that supports the drive shaft, and a cylindrical mirror that is disposed adjacent to the rotating polygon mirror and is coaxial with the drive shaft. Rotating polygon mirror device.