JP2565837Y2 - Light beam scanning device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a recording apparatus for a laser beam or the like.
Related to a light beam scanning device using a rotating polygon mirror
It is. In a light beam scanning device, a rotating polygon mirror is used.
In order to obtain the required characteristics,
The mounting position accuracy of the plane mirror becomes a problem. That is,
Depending on the mounting position of the surface mirror, the rotating polygon mirror may not be
And the rotating polygon mirror is tilted with respect to the rotation axis.
Can occur, which causes the rotating polygon mirror to
The light beam reflected by the mirror cannot scan a certain position,
There is a problem that the image becomes uneven. [0003] The present invention solves the above problems, and
Pivot axis,Fits on the free end side of the rotating shaftRotate
A rotating polygon mirror that scans the light beam, and the rotation axis is rotated
A light beam scanning device having a rotor portion for
AndWith the free end side of the rotating shaftRotating polygon mirrorIn charge of
A bullet that is stopped and presses the rotating polygon mirror toward the rotor unit side
The rotating polygon mirror is provided with a pressing force of an elastic means.
RProvided on the rotor sectionOn the receiving surfaceClose contact
It is characterized by the following. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
I will tell. In the example shown below, the rotary polygon mirror is provided with a laser device.
Light beam modulated by the signal to be recorded
I do. The polygon mirror rotates in one direction to produce this light beam.
Scan the camera. This scanned light beam is electrophotographic.
The light is incident on a light receiving member such as an optical body to form a desired image. FIGS. 1 and 2 show the structure of a conventional rotary polygon mirror.
Two examples are shown. In the figure, reference numeral 1 denotes a polygonal column-shaped periphery having a mirror surface on the side.
Known rotary polygon mirror, 2 is a rotating shaft, 5 is a rotating device (motor)
Is shown. In the configuration shown in FIG. 1, the rotating shaft 2 is
Bearing part 7 such as a ball bearing in casing 6 and
8 and a stay is provided on the inner wall of the casing 6.
The stator 10 provided with the coil 9 is mounted on the rotating shaft 2.
A rotor magnet 11 is mounted thereon. Koi
When the magnet 9 is energized, the magnet 11
The body rotates, which causes the polygon mirror 1 to rotate and the light beam
Is scanned. In the drawing, reference numeral 12 denotes a compression spring, and 13 denotes a rotating shaft.
The attached rotation detection disk, 14 is a rotation detection sensor.
And 15 are set screws for fixing the rotating polygon mirror to the rotating shaft.
Is shown. In the configuration of FIG. 2, the rotating shaft 2 is a rotating device.
5 in a casing 6 by bearings 7 and 8
2 is the same as that shown in FIG.
, A fixed inner cylinder 16 is provided at the center of the casing 6.
And a stator coil 17 is provided on the outer wall.
A theta 18 is provided and has an outer cylinder concentric with the inner wall 16.
The rotor magnet 20 is attached to the inner wall of the rotor 19
Then, the end wall of the rotor is fitted and fixed to the rotating shaft 2. Koi
The rotor 19 is integrated with the shaft 2 by energizing the
And the polygon mirror 1 also rotates integrally with the shaft 2
To scan the light beam. 12, 13, and 14 in the figure
Compression spring and rotation detection similar to those shown in FIG.
1 shows a disk for rotation and a sensor for detecting rotation. 21 is times
The polygonal mirror 1 is fixed to a flange 2 'provided on the rotating shaft 2.
This shows the screw for setting. In the configuration of the conventional rotating device as described above,
A part of the bearing part 7 is exposed to the rotary polygon mirror 1 side,
7 When the oil droplet (oil mist) 22 of the lubricating oil inside the shaft rotates
Oil droplets on the surface of the rotating polygon mirror 1 by scattering outside
They adhered, causing a decrease in reflectance. To prevent this
The magnetic seal, labyrinth, etc.
However, the effect is not enough in the long run. BookExampleOil splashes on such bearings
Prevents decrease in mirror reflectivity due to scatteringit can. More than
In the conventional example, the polygon mirror is fixed to the shaft with screws
Therefore, distortion of the polygon mirror due to the tightening force,
Occurs. This can cause the mirror surface to collapse
There is. [0011] The surface tilt refers to a laser emitted from a fixed position.
・ The beam is reflected by a rotating polygon mirror and the photoreceptor such as a photoreceptor
When scanning to the reference plane of each mirror surface
That is. Referring to FIG. 3, the rotating polygon mirror 1 rotates
The beam emitted from the laser device rotated by the rotating shaft 2
Is reflected by the mirror surface 1a and reaches the photoreceptor 3.
However, at this time, the mirror surface 1a is indicated by 1a 'with respect to the reference surface.
When such a large variation occurs, the scanning of the photosensitive member 3 is performed.
The position of the beam 4 is different for each mirror surface as indicated by 4 '.
Therefore, it appears as pitch unevenness on the image. [0012]Present inventionIs such an inconvenienceIs to solve
You. FIG. 4 shows an embodiment of the present invention. As shown in FIG.
In the embodiment, the same parts as those shown in FIG.
And the detailed description is omitted. This example
, The rotating device (motor) 5 is placed in the casing 6
The inner cylinder 16 is fixed, and the stator 18 is mounted on the outer wall thereof.
And a stator coil 17 is provided on this.things and
didIn this respect, the structure is the same as that of FIG.
Bearings such as ball bearings supported by 16Department
Supported by 7,8. However, the same as the inner cylinder 16
The rotor magnet 2 is mounted on the inner wall of the rotor 19 having the outer cylinder of the heart.
0, and the end wall of the rotor 19 is
The rotor is fitted and fixed on the rotating shaft 2 outside the rotor.19
Receiving surface 23 orthogonal to the rotation axis 2 is formed on the outer surface of the end wall of
The rotating polygon mirror 1 is fitted directly to the outer end of the rotating shaft 2.
The rotor19Attaching the rotating polygon mirror 1 with a smaller rotating diameter
The reference surface 24 is closely fixed to the receiving surface 23. That is, the rotary polygon mirror 1 isAnd rotor
19 receiving surfaces 23Position in the direction perpendicular to the axial direction
Since the decision has been made, the rotation polygon mirror
The center position accuracy can be obtained more accurately. As described above, the reference mounting surface 2 of the rotary polygon mirror 1
4 for rotor19 end wallsTightly attached to the receiving surface 23 formed in
In the illustrated embodiment, the elastic
To the retaining ring 21 (the inner diameter portion is locked to the shaft 2)
Therefore, the central part of the rotating polygon mirror is elastically pressed,
Thus, the polygon mirror 1 is pressed and held on the rotor end face 23. One
Mari polygon mirror 1 is a rotor19 receiversFriction force between surface 23
To the rotor 19, and thus torotationThe shaft 2 is integrally fixed
It is kept constant. By fixing in this way, many
Unreasonable force is not applied to the surface mirror 1 and mounting backlash occurs.
As shown in FIG. 3, there is no trouble,
Can record information. The rotary polygon mirror is connected to the rotor end by a set screw.
Screwed to the wall or glued and fixed with adhesive
Or any other appropriate fixing method. The aboveExampleIn the configuration by
Is fixedly fitted to the rotating shaft outside the bearing part.
Therefore, the bearing is not exposed to the rotating polygon mirror. Therefore, the axis
Oil droplets (oil mist) 22 generated in the receiving portion are
Splattered toward the inside of the
Not out of the motor. Also slightly out of the gap
Even if oil mist scatters, the rotating polygon mirror is
Is small, and is closely attached to the rotor.
It is not possible for the ilmist to go around and stain the mirror surface of the rotating polygon mirror.
Therefore, there is no possibility that the reflectance of the mirror surface will be reduced. Also,
Packing such as labyrinth and magnetic seal on bearing
It is not necessary to provide a device to improve productivity during assembly and manufacturing.
Is obtained. [0018]In the above embodiment, the rotating polygon mirror is
The mounting reference surface is formed on the end wall of the rotor.Firmly attached to the surface
It is fixed. Conventionally, a rotating polygon mirror is mounted with less falling
In order to achieve the orthogonal accuracy of the rotor and the rotating shaft and the rotating polygon mirror
It is necessary to have both the mounting flange of the
On the other hand, in the present embodiment, the orthogonal
When mounting a rotating polygon mirror
The amount of falling can be greatly reduced. Further, since the rotation diameter of the rotor is large,
Moment of inertia is obtained, and rotation accuracy is greatly improved.
The uneven rotation of the mirror can be prevented. As described above, according to the present invention,rotation
The rotating polygon mirror fitted to the free end of the shaft
To the bearing surface of the rotor, which is closer to the bearing.
Has beenIncreasing the mounting position accuracy of the rotating polygon mirror
It is possible,And the effect of shaft runout on the free end of the rotating shaft
Because it can be difficult to receiveRunning light beam
Eliminating unevenness can be eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross-sectional view showing a configuration of fixing a conventional rotary device and a rotary polygon mirror. FIG. 2 is a vertical cross-sectional view showing a configuration of fixing a conventional rotary device and a rotary polygon mirror. FIG. 3 is an explanatory view of the tilting of a rotary polygon mirror. FIG. 4 is a longitudinal sectional view showing an embodiment of the present invention. Apparatus 6 Casing 7, 8 Bearing part 9 Stator coil 10 Stator 11 Rotor magnet 12 Compression spring 13 Rotation detecting disk 14 Rotation detecting sensor 15 Set screw 16 Inner cylinder 17 Stator coil 18 ... stator 19 ... rotor 20 ... rotor magnet 21 ... holding ring 22 ... oil drop (oil mist)

Claims (1)

(57) [Claims for registering utility model] [1] The rotary shaft is fitted to the free end of the rotary shaft.
A rotary polygon mirror for scanning the light beam by rotating Ri, in the light beam scanning apparatus having a rotor section for rotating the rotary shaft, the engagement between the free end and the rotating polygon mirror of the rotary shaft Stopped
Elastic means for pressing the rotating polygon mirror toward the rotor section side
Wherein the rotary polygon mirror is in close contact with a receiving surface provided on the rotor section by a pressing force of an elastic means .