JPH03228012A - Motor for scanner - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy of a mirror surface by integrally forming a rotor boss for supporting a rotor magnet and a rotary shaft which is rotatably supported so that a rotor may be formed and disposing a laser light beam reflecting mirror surface on the surface of the rotor. CONSTITUTION:The rotor 14 is constituted by integrally forming the rotor boss 15 with the rotary shaft 16, and the rotary shaft 16 of the rotor 14 is rotatably supported by a bearing 12. A rotor yoke 4 on which the rotor magnet 3 is disposed is held by means of caulking, etc., by the rotor boss 15. Specular finishing is performed on the polygon surface of the rotor 14 so that the mirror surface 17 of a polygon mirror 18 may be formed. By such a constitution, the specular finishing on the mirror surface 17 can be directly performed with the rotary shaft 16 as a reference, so that the accuracy in the dimension from the rotation center to the mirror surface 17 and the accuracy in the surface tilt of the mirror surface 17 can be enhanced, and high quality in printing can be obtained in the case of using this motor in a laser beam printer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scanner motor having a mirror surface for reflecting laser light and used for deflecting light in a laser beam printer or the like.

Conventional technology In recent years, printers have been producing high-speed printing and high printing quality.

There is an increasing demand for laser beam printers with low noise characteristics. This laser beam printer deflects laser light emitted from a laser light source through a polygon mirror installed in a scanner motor, and scans the deflected laser light onto a photoreceptor through an imaging lens unit. It has become.

On the other hand, the high print quality that is a feature of laser beam printers is greatly affected by the angular variation between each mirror surface provided on the scanner motor and the incident laser beam. In other words, when an angular deviation (surface inclination) occurs in the mirror surface with respect to the rotation axis, axial deflection occurs in the reflected light. This causes the printed characters to have shading in one direction, resulting in a decrease in print quality. Therefore, the precision of each mirror surface in the scanner motor is important for high print quality.

Conventional scanner motors of this type generally have a configuration as shown in FIG. The configuration will be explained below.

As shown in the figure, a rotor boss (2) is press-fitted to the rotating shaft (1), and a rotor yoke (4) that fixes the rotor magnet (3) is fixed to this instep boss (2) by caulking or the like. ing. The polygon mirror (5) has a -mirror surface (6) formed on a polygonal surface, and this polygon mirror (5) has a presser foot (8) compressed by a retaining ring (7) and a rotor boss (2). The drive coil (9) is held in place by the rotor magnet (3).
)c! : Arranged with a predetermined gap in the axial direction, and fixed to the stator substrate (10) by adhesive or the like. The stator yoke (11) constitutes the magnetic circuit of the rotor magnet (3). The bearing (12) supports the rotating shaft (1) and is fixed to the housing 13).

The scanner motor configured as described above generates rotational torque in the rotor magnet (3) by controlling the supply of electricity to the drive coil (9). Further, the presser spring (8) is used to adjust the pressure so that the mirror surface (6) of the polygon mirror (5) is not distorted when the polygon mirror (5) is held on the rotor boss (2).

Problems to be Solved by the Invention In such a conventional scanner motor, the polygon mirror (5) is attached by a stopper (7), a presser foot (8), and a rotor boss (2), so the number of parts is reduced. There was a problem that the workability was poor and the cost was high. Furthermore, in order to prevent the surface of the polygon mirror (5) from tilting, it is necessary to precisely process the end surface of the polygon mirror (5) and the mounting surface of the rotor boss (2), which also has the disadvantage of further increasing manufacturing costs. Ta.

The present invention solves the above problems, and improves the dimensional accuracy from the rotation axis to the mirror surface or the inclination accuracy of the mirror surface, reduces the number of parts that tend to be used (and improves workability and reduces costs). It is an object.

Means for Solving the Problems In order to achieve the above object, the present invention forms a rotating body by integrating a rotor boss that supports a rotor magnet and a rotating shaft that is rotatably supported, and a rotor boss that supports a rotor magnet and a rotating shaft that is rotatably supported. A means to solve the problem is to provide a small number of mirror surfaces (at least one surface) for reflecting laser light.

Effect of the present invention By using the above-mentioned problem solving means, the mirror surface can be processed based on the rotation axis, and the dimensional accuracy from the rotation center to the mirror surface and the surface tilt accuracy of the mirror can be improved. High print quality can be obtained when used in

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. In addition, as shown in the figure in which the same configuration as the conventional example is given the same reference numerals and the explanation is omitted, the rotating body (14) is integrally formed with the rotor boss (15) and the rotating shaft (16). , the rotation axis (1) of this rotating body (14)
6) is rotatably supported by a bearing (12). The rotor boss (15) holds the rotor yoke (4) on which the rotor magnet (3) is arranged by caulking or the like. The polygonal surface of this rotating body (14) is processed as a mirror surface 17) to form a polygon mirror (18).

With the above configuration, the mirror surface (
17) can be directly processed, it is possible to improve the dimensional accuracy from the rotation center to the mirror surface (17) and the surface tilt accuracy of the mirror surface (17), and when used in laser beam printers etc., high printing quality can be achieved. can get.

Furthermore, the number of parts that hold the polygon mirror (18) can be reduced, and costs can be reduced.

Next, FIGS. 3 and 4 show other embodiments of the present invention.
This will be explained with reference to the figures. Components having the same configuration as those in the first embodiment are given the same reference numerals and explanations will be omitted.

As shown in the figure, the rotating body (19) is connected to the rotor boss (20).
and a rotating shaft (21) are integrally formed, the rotating shaft (21) of this rotating body (19) is rotatably supported by a bearing (12), and the rotor boss 20 is supported by a rotor magnet (3). It holds a rotor yoke (4) with a One end of the rotating body (19) is processed into a mirror surface (22).

The scanner motor configured as described above can obtain the same effects as the first embodiment.

Effects of the Invention As is clear from the above embodiments, according to the present invention, a rotor boss that supports a rotor magnet and a rotating shaft rotatably supported are integrated to form a rotating body, and a laser beam is applied to the rotating body. Since at least one reflective mirror surface is provided, mirror surface processing can be performed directly using the rotation axis as a reference, and the dimensional accuracy from the rotation center to the mirror surface and the mirror surface tilt accuracy can be improved, allowing the laser beam to When used in printers, etc., high print quality can be obtained. Furthermore, it is possible to provide a practically excellent scanner motor that can reduce the number of parts that hold the polygon mirror and reduce costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a scanner motor according to an embodiment of the present invention, FIG. 2 is a perspective view of a rotating body of the scanner motor, and FIG.
The figure is a sectional view of a scanner motor according to another embodiment of the present invention.
FIG. 4 is a perspective view of the rotating body of the scanner motor, and FIG. 5 is a sectional view of the conventional scanner motor. (14) ...Rotating body, (15) ...Rotor boss, (16) ...Rotating shaft, (17) ...Mirror surface.

Claims (1)

[Claims] A rotor boss supporting a rotor magnet and a rotatably supported rotating shaft are integrated to form a rotating body, and at least one mirror surface for reflecting laser light is provided on the surface of the rotating body.
A scanner motor with more than one surface.