JPH09105879A - Deflection scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the assembly of a rotary polygon mirror to a motor and to prevent an excessive thrust load from being placed during the assembling operation. SOLUTION: On the reverse surface of a flange member 4 united with a shaft 3, the rotor 5 of the motor M1 is fixed and on the top surface of a flange member 4, the rotary polygon mirror 8 is assembled. This assembling operation is performed by fitting a fixed pin 4a stood on the flange member 4 loosely in the through hole 8c of the rotary polygon mirror 8, and charging and setting photosetting resin 9 with light L. No large external force is needed to assemble the rotary polygon mirror 8, and the thrust load placed on the shaft 3 is only the weight of the rotary polygon mirror 8. Further, neither a G ring nor a leaf spring is needed and the assembling process is easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection scanning device used for laser printers, laser facsimiles and the like.

[0002]

2. Description of the Related Art An example of an optical deflection scanning device used in a laser printer or a laser facsimile will be described with reference to FIGS. First, in FIG. 4, the light beam generated from the semiconductor laser S is collimated by the collimator lens C ₁ , then linearly condensed by the cylindrical lens C ₂ , and irradiated on the reflecting surface 108 a of the rotary polygon mirror 108. The light beam deflected and scanned by the rotary polygon mirror 108 is imaged on a photoconductor on a rotating drum (not shown) by an imaging lens system F including a spherical lens F ₁ and a toric lens F _2, and is mainly rotated by the rotation polygon mirror 108. scanning,
And an electrostatic latent image is formed on the photoconductor by sub-scanning by rotation of the rotary drum.

As shown in FIG. 5, a driving device for rotating the rotary polygon mirror 108 includes a bearing housing 101a fixed to an optical box 101 and a bearing 102 held by the housing.
a and 102b have a shaft 103 rotatably supported,
The shaft 103 is connected to the yoke 105a via the flange member 104.
And a rotor 105 including a driving magnet 105b
And the rotor 105 is fixed to the housing 101a.
A motor M ₀ is configured with 06. Rotating polygon mirror 108
Is a leaf spring 109a and a washer 10 mounted on the shaft 103.
Elastic pressing means 1 including 9b and G ring 109c
09 presses against the flange member 104, thereby integrally connecting with the rotor 105, and the motor M ₀
Driven to rotate.

[0004]

However, according to the above-mentioned conventional technique, the elastic pressing means for pressing the rotary polygonal mirror against the flange member as described above comprises a leaf spring, a washer and a G ring fixed to the shaft. , 15 to push down the G ring along a shaft to a predetermined fixed position (for example, a groove provided on the shaft) while elastically deforming the leaf spring fitted to the shaft when assembling the rotary polygon mirror. It requires a force of 20 kgf, which causes excessive thrust on the shaft, which can result in bearing damage and impaired motor performance. Further, since the number of parts forming the elastic pressing means is large, the manufacturing cost of the deflection scanning device increases, and when the rotary polygon mirror is made of resin, the rotary polygon mirror is pressed by the pressing force of the elastic pressing means. There is also a possibility that a large amount of distortion will be generated, which will deform the reflecting surface and deteriorate the optical performance of the deflection scanning device.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and when assembling a rotary polygon mirror to a rotor of a motor, many parts are not required and the assembling work is simple. It is therefore an object of the present invention to provide a deflection scanning device in which there is no fear that an excessive thrust load will be applied to the rotor shaft.

[0006]

In order to achieve the above object, the deflection scanning device of the present invention connects a rotary polygonal mirror having at least one through hole and a reflected light of the rotary polygonal mirror to a photoconductor. An image forming unit for forming an image, a rotating member which has a protruding portion loosely fitted in a through hole of the rotating polygon mirror and which is adhered to the rotating polygon mirror by a photo-curing resin filled around the rotating member, and the rotating member is rotated. It is characterized in that it has a driving means for driving.

It is preferable that a plurality of through-holes be provided in the rotary polygon mirror and that these holes be arranged symmetrically about the central axis of the rotary polygon mirror.

The cross-sectional dimension of the through hole may be changed stepwise or continuously in the thickness direction of the rotary polygon mirror.

[0009]

In assembling the rotary polygon mirror to the driving means such as the motor, first, the rotary member such as the flange member which is integral with the shaft is coupled to the rotor of the motor, and the rotary member is projected into the through hole of the rotary polygon mirror. The part is loosely fitted, and a photo-curing resin is filled around the part to cure it.

Since the projecting portion of the rotating member is only loosely fitted in the through hole of the rotary polygon mirror, a large external force is not required as in the case of assembling a G ring or the like, and the thrust load applied to the shaft is rotated in this step. Only the weight of the polygon mirror. Therefore,
There is no risk of bearing damage or loss of motor performance.

In addition, since the rotary polygon mirror is fixed to the flange member or the like by the adhesive force of the photocurable resin, no assembly parts such as a leaf spring and a G ring are required, and the number of assembly parts of the deflection scanning device is increased. This greatly contributes to the reduction of manufacturing cost and simplification of the assembly process.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial schematic cross-sectional view showing the main part of the deflection scanning device according to the first embodiment, which is an optical box 1 having a bearing housing 1a and a pair of balls held by the bearing housing 1a. The rotor 3 includes a shaft 3 rotatably supported by bearings 2a and 2b, a flange member 4 that is a rotary member fixed to the shaft 3, and a rotor 5 integrally connected to the shaft 3 through the flange member 4. 5 comprises a yoke 5a and a magnet 5b. A motor board 7 on which a stator 6 is mounted is fixed to the upper surface of the bearing housing 1a, and the rotor 5 and the stator 6 constitute a motor M ₁ that is a driving means.

Laser light emitted from a light source (not shown) is linearly focused on the reflecting surface 8a of the rotary polygon mirror 8 and is scanned in a predetermined scanning direction by the rotation of the rotary polygon mirror 8. The scanning light, which is the reflected light of the rotary polygon mirror 8 thus scanned, is imaged on the photoconductor on the rotary drum by an imaging lens system which is an imaging means (not shown), and is rotated by the rotation polygon mirror 8. An electrostatic latent image is formed on the photoconductor by main scanning and sub-scanning by rotation of the rotating drum.

The rotary polygon mirror 8 is a regular hexagonal columnar member in which six side surfaces are mirror-finished to form reflecting surfaces 8a, and a central hole 8b into which the shaft 3 is fitted and a flange member 4 are formed.
1 has a through hole 8c into which a pair of fixing pins 4a, which are protruding parts, are loosely fitted, and the inner diameter of each through hole 8c is as shown in FIG. The fixing of the fixed pin 4a is set so that a gap A having a predetermined size is formed around the fixed pin 4a. Assembling of the rotary polygon mirror 8 to the rotor 5 of the motor M ₁ is performed by the center hole 8b of the rotary polygon mirror 8. The shaft 3 is fitted to the shaft 3, the through holes 8c of the rotary polygon mirror 8 are fitted to the fixing pins 4a of the flange member 4, and the gap A around each fixing pin 4a is filled with the photo-curing resin 9 to be fixed. It is performed by curing with the light L.

The through holes 8c of the rotary polygonal mirror 8 are arranged axially symmetrically on the circumference of a radius r from the center of the rotary polygonal mirror 8, and each fixing pin 4a of the flange member 4 also extends from the center of the flange member 4. They are arranged symmetrically on the circumference of a radius r. This is because when the rotary polygon mirror 8 is rotated together with the flange member 4 and the rotor 5, there is a significant dynamic imbalance due to the imbalance of mass due to the through holes 8c of the rotary polygon mirror 8 and the flange member 4 and the fixed pin 4a. This is to prevent noise from being generated and the optical characteristics of the deflection scanning device from changing due to the vibration caused by such dynamic imbalance.

The numbers of the through holes 8c of the rotary polygon mirror 8 and the fixing pins 4a of the flange member 4 are not limited to one pair, and three or more holes may be provided on the circumference at equal intervals.

According to the present embodiment, when the rotary polygon mirror is assembled to the flange member, the fixing pins of the flange member are loosely fitted in the through holes of the rotary polygon mirror as described above, and the light curing is performed around the fixing pins. The resin is filled and cured, and the thrust load applied to the shaft through the rotary polygon mirror is only the weight of the rotary polygon mirror. Depending on the situation, it may be necessary to hold the rotating polygonal mirror so that it does not move in the process of curing the photo-curing resin, but the load required for this is small and the axis is too large as in the case of using the conventional G ring. There is no risk of applying a heavy thrust load. Further, since it is not necessary to separately manufacture and assemble the G ring and washer, the number of assembly parts and the number of assembly steps of the deflection scanning device can be significantly reduced, and automation of the assembly process can be greatly promoted.

In addition, when a rotary polygon mirror made of synthetic resin is used, since the rotary polygon mirror is soft and the reflecting surface tends to be deformed by the thrust load, it is difficult to reduce the thrust load in this way. This is particularly important for ensuring the optical characteristics of the deflection scanning device.

When the rotary polygon mirror is made of a transparent synthetic resin, the photocurable resin filled around each fixing pin can easily reach the light, so that the curing is performed quickly and the rotating pin and the rotating pin are rotated. The added advantage is that the bond strength of the polygon mirror is also improved.

FIG. 2 shows a modification, which is an upper half portion 18d of each through hole 18c formed in the rotary polygon mirror 18.
The inner diameter of is increased and the step area 18f between the lower half portion 18e and the photocurable resin 19 and the rotary polygon mirror 18 is increased to increase the coupling force between the flange member 14 and the rotary polygon mirror 18. To strengthen. In addition, the photocurable resin 19
Since the light for curing the resin can reach deep inside the through hole 18c smoothly, the light curing resin
2B, the upper half of the fixed pin 14 can be hardened even when the fixed pin 14a of the flange member 14 is eccentrically fitted into the through hole 18c of the rotary polygon mirror 18, as shown in FIG. 2B. The entire circumference of the part is firmly bonded to the rotary polygon mirror 18 by a photo-curing resin 19. That is, it is possible to avoid a trouble that one side surface of the fixing pin 14a is left completely unbonded and the coupling force between the rotary polygon mirror 18 and the flange member 14 is insufficient.

Further, instead of providing the step 18f in each through hole 18c of the rotary polygon mirror 18, as shown in FIG. 3, the through hole for tapering the inner diameter from the upper end 28d having a large diameter to the lower end 28e having a small diameter is formed. The rotary polygon mirror 28 having 28c may be used. This has an advantage that the rotary polygon mirror 28 can be easily molded when it is made of synthetic resin, and also, it is possible to form a textured pattern on the inner surface of the through hole 28c or to form a spline groove. Therefore, the advantage that the binding force to the photocurable resin 29 can be further strengthened is added.

[0023]

Since the present invention is configured as described above, it has the following effects.

When assembling the rotary polygon mirror to the rotor of the motor, many parts are not required and the assembling work is easy, and an excessive thrust load is applied to the rotor shaft, which damages the bearing. There is no fear that the performance of the motor will be impaired. As a result, an inexpensive and high-performance deflection scanning device can be realized.

[Brief description of the drawings]

1A and 1B show a main part of a deflection scanning device according to an embodiment, FIG. 1A is a schematic partial cross-sectional view thereof, and FIG. 1B is an enlarged partial cross-sectional view showing the vicinity of a fixing pin in an enlarged manner.

FIG. 2 shows a modified example, in which (a) is an enlarged partial cross-sectional view showing the vicinity of the fixing pin in an enlarged manner, and (b) is a case where the fixing pin is eccentrically assembled with respect to the through hole. It is an expanded partial sectional view showing.

FIG. 3 is an enlarged partial sectional view showing the vicinity of a fixing pin of another modification in an enlarged manner.

FIG. 4 is a plan view showing a deflection scanning device according to a conventional example.

5 is a schematic partial cross-sectional view showing a main part of the apparatus of FIG.

[Explanation of symbols]

 1 Optical Box 3 Axis 4,14 Flange Member 5 Rotor 6 Stator 8,18,28 Rotating Polyhedral Mirror 8c, 18c, 28c Through Hole 9,19,29 Light Curing Resin

Claims (3)

[Claims] 1. A rotary polygonal mirror having at least one through-hole, an image forming means for forming an image of reflected light of the rotary polygonal mirror on a photosensitive member, and a projection portion loosely fitted in the through-hole of the rotary polygonal mirror. A deflection scanning device having a rotating member adhered to the rotary polygonal mirror by a photo-curing resin filled around the rotating member, and a driving unit for rotating the rotating member. 2. The rotary polygon mirror is provided with a plurality of through holes,
2. The deflection scanning device according to claim 1, wherein these are arranged in axial symmetry about the central axis of the rotary polygon mirror. 3. The deflection scanning device according to claim 1, wherein the cross-sectional size of the through hole changes stepwise or continuously in the thickness direction of the rotary polygon mirror.