JPH0519199A - Fixing mechanism for rotary mirror - Google Patents

Abstract

PURPOSE:To fix a rotary mirror without imposing a load on a thrust bearing part by arranging a rotary mirror on a flange fixed on a rotary shaft and fixing the rotary mirror on the flange by a fixing member. CONSTITUTION:The rotary mirror 13 is placed on the flange 12 which is press- fitted and fixed on the rotary shaft 11 so as to easily exchange the mirror 13. In the case of fixing the mirror 13, a horizontal hole 14 is provided in the necessary spot of the shaft 11 near the upper part of the mirror 13 in order not to impose the load on the X direction of the thrust bearing part. Then, a bowed fixing spring 15 is inserted through the hole 14, and thereafter both ends of the spring 15 are reversed with the hole 14 as the center of reversal so as to press the mirror 13. Thus, the mirror 13 between the flange 12 and the spring 15 is fixed in a state where the load is not imposed on the thrust bearing part with the spring pressure of the spring 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing mechanism for a rotary mirror used in a deflection scanning device such as a laser beam printer or a digital copying machine.

[0002]

2. Description of the Related Art Conventionally, a hydrodynamic bearing which rotates in a non-contact manner has been used as a bearing for a laser beam printer, a digital copying machine or the like which requires a high speed and high precision rotating device.

FIG. 12 is a sectional view of a rotating device in a deflection scanning device used in a laser beam printer. The rotary shaft 1 is rotatably fitted in a sleeve 2, and the lower end of the sleeve 2 is supported by a fixed plate 4 via a thrust plate 3, and the fixed plate 4 is fixed to an outer cylinder 5. A flange 6 is press-fitted and fixed to the rotary shaft 1, a rotary mirror 7 is mounted on the upper portion of the flange 6, and a yoke 9 having a drive magnet 8 is fixed to the lower portion of the flange 6. A coil 10 is fixed to the outer cylinder 5 so as to face the driving magnet 8.

[0004]

However, in this conventional example, when the rotary mirror 1 is fixed to the sleeve 2, a load is applied to the thrust bearing portion, which causes damage, deformation or non-rotation of the bearing portion. There is fear.

The object of the present invention is to solve the above problems,
It is an object of the present invention to provide a rotating mirror fixing mechanism capable of fixing a rotating mirror to a rotating shaft without applying a load to the thrust bearing portion.

[0006]

A fixing mechanism for a rotary mirror according to the present invention for achieving the above object has a flange fixed to a rotary shaft, a rotary mirror mounted on the flange, and a fixing member. It is characterized in that the rotating mirror is pressed and fixed to the flange.

[0007]

The fixing mechanism of the rotary mirror having the above-mentioned structure utilizes the spring pressure or magnetic force of the fixing member to press and fix the rotary mirror to the flange without applying a load to the thrust bearing portion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. The same reference numerals as those in the conventional example represent the same members. FIG. 1 shows a first embodiment of a rotary mirror fixing mechanism to which the present invention is applied, in which a rotary mirror 13 is placed on a flange 12 which is press-fitted and fixed to a rotary shaft 11. The reason why the rotary mirror 13 is not directly press-fitted or bonded to the rotary shaft 11 is to facilitate replacement of the rotary mirror 13. In order to prevent the load from being applied to the thrust bearing portion in the X direction when fixing the rotary mirror 13, a lateral hole 14 is provided in a required portion of the rotary shaft 11 near the upper portion of the rotary mirror 13, and the lateral hole 14 is provided in the lateral hole 14. As shown in Fig. 1 (a), a bow-shaped fixed spring 1
5 is inserted, and thereafter, as shown in FIG. 1 (b), both ends of the fixed spring 15 are inverted so as to press the rotary mirror 13 with the lateral hole 14 as the inversion center.

As a result, the flange 12 and the fixed spring 15 are
The rotating mirror 13 in between can be fixed without the load being applied to the thrust bearing portion by the spring pressure of the fixed spring 15.

In this embodiment, the fixed spring 15 is inserted upward, but it may be arranged sideways or obliquely. Further, even when the fixed spring 15 is directed downward, the same effect can be obtained by deforming the fixed spring 15 using a jig and inserting the fixed spring 15.

FIG. 2 shows a second embodiment in which a shape memory alloy or a shape memory polymer is used as the material of the fixed spring 15, and as shown in FIG. When the fixing spring 15 is inserted, the fixed spring 15 has a substantially linear shape. However, by heating the fixed spring 15 to about 60 ° C. after insertion, it is deformed into an arched shape as shown in FIG. 2B, and the rotary mirror 13 can be pressed as in the first embodiment. However, the shape memory material used must be one-way (one direction).

A fixed spring made of bimetal can also be used. For example, if a linear bimetal fixed spring heated to about 60 ° C. is inserted into the lateral hole 14 as shown in FIG. As shown in FIG. 2 (b), the same effect can be obtained by transforming the shape into a bow shape.

In the third embodiment shown in FIG. 3, a corrugated washer 16 and a holding plate 17 are arranged on the upper surface of the polygonal mirror 13, and an arcuate fixing pin 18 is inserted into the lateral hole 14 thereover. There is.

In this embodiment, the corrugated washer 16 elastically presses the rotary mirror 13 so that the lateral hole 14 is formed as shown in FIG.
By inserting the fixing pin 18 as shown in (a) and reversing the fixing pin 18 with the lateral hole 14 as the reversing center, the corrugated washer 16 is crushed as shown in (b),
The rotating mirror 13 is pressed and fixed without applying a load to the thrust bearing portion.

FIG. 4 is a sectional view of a fourth embodiment utilizing the magnetic force effect. Flange 12 press-fitted and fixed to rotating shaft 11
A rotary mirror 13 is placed on the above. Here, the flange 12 is a ferromagnetic material such as iron or iron alloy, and a ring-shaped fixing magnet 19 is bonded to the back side of the rotating mirror 13.

Therefore, the rotary mirror 13 is fixed to the flange 12 by attraction by the magnetic force between the flange 12 which is a ferromagnetic material and the fixing magnet 19 attached to the rotary mirror 13. Further, although the fixing magnet 19 has a ring shape, the same effect can be obtained by arranging the fixing magnet 19 at two or more opposing positions.

FIG. 5 is a sectional view showing the fifth embodiment.
The material of the flange 12 is a non-magnetic material such as copper, aluminum or plastic, a fixing magnet 20 is provided on the upper surface of the flange 12, and a ferromagnetic facing yoke 21 is arranged on the back side of the rotating mirror 13 and fixed. Magnet 2
0 and the opposing yoke 21 exert a magnetic force on the rotary mirror 1
3 is fixed to the flange 12.

FIG. 6 shows a sixth embodiment in which the rotating mirror 13 itself is made of a ferromagnetic material, and the rotating mirror 13 is acted upon by a magnetic force between the rotating mirror 13 and a fixing magnet 20 provided on the flange 12. Is fixed on the flange 12.

FIG. 7 shows a seventh embodiment, in which an arm 22 is attached through a hole 13a formed in the rotary mirror 13 so as to cover the rotary mirror 13. A fixing magnet 23 is fixedly adhered to each tip of the arm 22, and a yoke 9 which is a ferromagnetic material connected to the flange 12 is arranged in the vicinity of the fixing magnet 23. Due to the magnetic force between 23 and the yoke 9, the rotary mirror 1
3 is fixed to the flange 12.

FIG. 8 shows an eighth embodiment, in which a plastic magnet is used for the arm 22 itself and has the same effect as that of the embodiment of FIG.

Also, in the ninth embodiment of FIG. 9, the arm 22
Is a ferromagnetic material, and the rotating mirror 13 is fixed by the magnetic force of the fixing magnet 20 provided on the upper portion of the flange 12.

Further, in the tenth embodiment shown in FIGS. 10 and 11, the magnetic force of the driving magnet 8 is used for the arm 22 made of a ferromagnetic material. That is, the arm 22 extends from the outside of the effective reflection area a of the rotating mirror 13 to the vicinity of the driving magnet 8 through the hole 9 a provided in the yoke 9, and the rotating mirror is generated by the magnetic force of the driving magnet 8. 1
3 is fixed to the flange 12.

In the above embodiments, the description has been limited to the hydrodynamic bearing, but even in a rotating mechanism using a ball bearing, a large thrust load causes inaccuracy in accuracy, so the present invention can be applied. it can. Further, although the description has been given based on the circumferentially opposed type motor, the same effect can be obtained by using the surface opposed type motor.

[0024]

As described above, in the rotating mirror fixing mechanism according to the present invention, the rotating mirror is arranged on the flange fixed to the rotating shaft, and the rotating mirror is fixed to the flange by the fixing member. It is possible to fix the rotating mirror without applying a load to the thrust bearing portion.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a sectional view of a third embodiment.

FIG. 4 is a sectional view of a fourth embodiment.

FIG. 5 is a sectional view of a fifth embodiment.

FIG. 6 is a sectional view of a sixth embodiment.

FIG. 7 is a sectional view of a seventh embodiment.

FIG. 8 is a sectional view of an eighth embodiment.

FIG. 9 is a sectional view of a ninth embodiment.

FIG. 10 is a sectional view of a tenth embodiment.

FIG. 11 is a plan view.

FIG. 12 is a sectional view of a conventional rotating device.

[Explanation of symbols]

11 rotation axis 12 flange 13 rotating mirror 14 horizontal holes 15 Fixed spring 16 Wavy washers 17 Presser plate 18 fixing pin 19, 20, 23 Fixed magnet 22 arms

Claims (3)

[Claims] 1. A rotary mirror, wherein a flange is fixed to a rotary shaft, a rotary mirror is placed on the flange, and the rotary mirror is pressed and fixed to the flange by a fixing member. Fixing mechanism. 2. The fixing mechanism for a rotary mirror according to claim 1, wherein the fixing member is a spring. 3. The fixing mechanism for a rotary mirror according to claim 1, wherein the fixing member is a magnetic member.