JPH11264951A - Deflection scanning device - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a deflection scanning device capable of firmly fixing a stator of a deflector to a motor circuit board, reducing vibration and noise, and simplifying the process. The stator includes a mold core on which a winding is wound, and an L-shaped stator pin that is electrically connected to the winding and is arranged approximately equally in a circumferential direction of the mold core. The positioning pins are fitted into positioning holes formed in the motor circuit board 28 to perform positioning of the stator.
8. A deflection scanning device in which one end of the L-shaped stator pin 42 is fixed to the motor circuit board 28 in close contact with the motor circuit board 28.

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 an image forming apparatus such as a laser beam printer and a laser facsimile.

[0002]

2. Description of the Related Art A deflection scanning device used in an image forming apparatus such as a laser beam printer or a laser facsimile reflects a light beam such as a laser beam by a rotating polygon mirror rotating at a high speed. The scanning light of the rotating polygon mirror thus obtained is formed on a photosensitive member on a rotating drum to form an electrostatic latent image. Next, the electrostatic latent image on the photoreceptor is visualized into a toner image by a developing device, transferred to a recording medium such as recording paper and sent to a fixing device, and the toner on the recording medium is heated and fixed to perform printing. Done. For example, FIG.
FIG. 1 shows a main part of a deflector of a deflection scanning device according to a conventional example disclosed in Japanese Patent No. 27846, which includes a bearing 10.
The flange member 103 is integrated with the rotating shaft 102 fitted into the rotor shaft 105 and the rotor frame 105 is attached to the flange member 103.
The rotor magnet 104 is fixed, and the rotary polygon mirror 106 is pressed against the flange member 103 to be integrally connected thereto, and the stator 10 erected on the motor circuit board 107 is fixed.
By exciting 8, the rotor magnet 104 and the rotary polygon mirror are integrally rotated.

[0003] The stator 108 is provided with an insulator 1 on a stator core 112 made of a laminate of, for example, a silicon steel plate.
13, a winding 114 is wound.
As described in Japanese Patent Application Publication No. 55-55, the insulator 113 has a projection inserted into the motor circuit board and sandwiched by the bottom plate, and the projection is fixed to the bottom plate by welding. There is also a method of fixing the stator 108 to the motor circuit board 107 by screwing.

[0004]

However, according to the above-mentioned prior art, the stator of the deflector in the deflection scanner is not completely fixed to the motor circuit board. When the balance is large, the self-excited vibration of the stator becomes large, and this vibration is transmitted to the motor circuit board, causing a problem that the sound becomes loud. Also, since the insulator and the bottom plate are heat-welded, the number of parts increases and the manufacturing cost increases.When the stator is screwed to completely fix the motor circuit board, the material and thickness of the motor circuit board are reduced. It is necessary to devise the shape, which causes a rise in material costs and processing costs.

Accordingly, the present invention solves the problems of the prior art described above, and enables the stator of the deflector in the deflection scanning device to be firmly fixed to the motor circuit board, reducing vibration and noise and reducing the number of parts. And the process can be simplified.
It is an object of the present invention to provide an inexpensive and high-performance deflection scanning device.

[0006]

According to the present invention, in order to achieve the above-mentioned object, the deflection scanning device is constituted as follows. That is, the deflection scanning device of the present invention includes a rotating shaft rotatably fitted to a fixed sleeve, a flange member fixed to the rotating shaft, a rotary polygon mirror fitted and supported on the flange member, It has a drive unit having a rotor magnet integrated with the flange member and a stator opposed thereto, and a shallow groove for generating dynamic pressure is provided on the inner peripheral surface of the fixed sleeve or the outer peripheral surface of the rotating shaft,
In a deflection scanning device that constitutes a dynamic pressure bearing in which lubricating oil is interposed in a gap between the fixed sleeve and the rotating shaft, the stator includes a mold core wound with a winding, and the mold core being electrically connected to the winding. And L-shaped stator pins arranged approximately equally in the circumferential direction, and positioning of the stator by fitting positioning pins provided on the stator into positioning holes formed in the motor circuit board, The bottom surface of the stator is brought into close contact with the motor circuit board to
One end of the letter-shaped stator pin is fixed to the motor circuit board. Further, in the deflection scanning device of the present invention, the rotating shaft rotatably fitted to the fixed sleeve, and the positioning pin fixed to the rotating shaft has an outer diameter larger than a diameter of a positioning hole formed in the motor circuit board. Has,
The positioning pin is press-fitted into the positioning hole or bonded after press-fitting. Also,
The deflection scanning device according to the present invention is characterized in that the mold core is configured to be press-fitted into the outer periphery of the fixed sleeve. Further, in the deflection scanning device according to the present invention, preferably, a position where the mold core is pressed into an outer periphery of the fixed sleeve corresponds to a position where a shallow groove on an inner peripheral surface of the fixed sleeve is not provided. It is characterized by being. Further, the deflection scanning device of the present invention is characterized in that at least a part of the press-fitted portion on the outer periphery of the fixed sleeve is larger in diameter than a portion of the fixed sleeve that is not press-fitted.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a deflection scanning apparatus having the above-described configuration, a stator core and an insulator are integrated, and an L-shaped stator pin in which the stators are equally spaced in the circumferential direction is soldered or an L-shaped stator pin is soldered. In addition to the attachment, press-fitting of the positioning pins and press-fitting of the mold core into the fixing sleeve allow the rotor to be completely fixed to the motor circuit board, thereby improving the vibration characteristics and noise characteristics of the rotor against imbalance and cogging torque. In addition, since a bottom plate and screws are not required and steps such as heat welding and screw hole processing can be omitted, a high-performance and low-cost deflection scanning device can be provided.

[0008]

Embodiments of the present invention will be described below. Embodiment 1 FIG. 1 shows a main part of a deflection scanning apparatus according to Embodiment 1 of the present invention. In a deflector 24, a motor circuit fixed to an optical box 21 as shown in a sectional view of FIG. A fixed sleeve 29 is erected on the substrate 28 and the fixed sleeve 2
A rotating shaft 30 is rotatably fitted to 9. A flange member 31 made of aluminum, brass, or the like is fixed to the outer periphery of the rotating shaft 30 by shrink fitting or the like, and a rotating polygon mirror 32 for reflecting a light beam is fixed on an upper surface of the flange member 31 by a pressing spring 33. The drive magnet 34 is fixed to the lower part of the outer periphery of the flange member 31 by shrink fitting and fixed by bonding or the like. A stator 35 is arranged on the upper surface of the motor circuit board 28 so as to face the drive magnet 34. The inner diameter of the fixed sleeve 29 has herringbone-shaped grooves 36 and 37. Numeral 38 denotes a thrust plate which is in contact with the spherical portion (arc having a large radius) at the lower end of the rotating shaft 30. Reference numeral 39 denotes lubricating oil injected into a gap between the fixed sleeve 29 and the rotating shaft 30.

With such a configuration, when the deflector 24 rotates, the rotating shaft 30 is supported and rotated by a part of the spherical portion at the lower end contacting the thrust plate 38. At this time, in the radial direction, the rotary shaft 30 floats by the pumping action of the lubricating oil injected into the herringbone-shaped groove provided on the inner diameter of the fixed sleeve 29 and can be rotated in a non-contact manner. Here, the stator 35 is formed by stacking a plurality of silicon steel plates as shown in FIG.
0 is inserted into a mold core 41 by insert molding using a resin such as PPS (polyphenylene sulfide) to wind a winding 44 around the stator core 4.
2 is press-fitted equally in the circumferential direction, is electrically connected to the winding 44, and is bent into an L-shape. A plurality of positioning pins 43 are provided below the mold portion of the stator 35, and at least two or more of them are fitted into positioning holes 45 provided in the motor circuit board 28 as shown at 43-a to perform positioning. In the state where the bottom surface of the stator 35 is in close contact with the motor circuit board 28, the L-shaped stator pins 42, which are equally spaced in the circumferential direction, are soldered to the upper surface of the motor circuit board 28, so that conduction is achieved. It is firmly fixed. The pins other than the two or more positioning pins 43-a to be fitted may be loose like 43-b.

FIG. 3 is a schematic plan view of the first embodiment. A laser unit 22 is attached to a part of an optical box 21, and a cylindrical lens 23 is moved in a traveling direction of a laser beam from the laser unit 22. And deflector 24
Are arranged inside the optical box 21. In the traveling direction of the laser beam deflected by the deflector 24, a lens 25,
Reference numeral 26 is arranged inside the optical box 21, and the photosensitive drum 27 is arranged outside the optical box 21. Then, the laser beam from the laser unit 22 is condensed on the rotary polygon mirror 32 of the deflector 24 by the cylindrical lens 23 and is deflected and scanned by the rotary polygon mirror 32. The deflected laser beam is scanned at a constant speed while being focused on the photoconductor 27 by the lenses 25 and 26.

At this time, since the stator 35 has the stator core 40 and the mold formed integrally with each other, the stator 35 is excellent in vibration absorption as a single stator. L equally spaced in the circumferential direction
Since it can be firmly fixed to the motor circuit board 28 by soldering the letter-shaped stator pins 42,
For example, even when the rotor unbalance or cogging torque is large, self-excited vibration of the stator 35 itself and vibration transmitted to the motor circuit board 28 and the optical box 21 can be suppressed, and noise can be reduced. Also, a bottom plate and a heat welding step are not required for fixing the stator, and as a result, a deflection scanning device having excellent vibration characteristics and being inexpensive can be provided.

Second Embodiment FIG. 4 shows a main part of a second embodiment of the present invention. Note that the same reference numerals as those in the first embodiment denote the same parts. This is because the diameter of the positioning pin 46 extending downward from the mold portion of the mold core 41 is made larger than the positioning hole 47 provided on the motor circuit board, and the stator 48 is press-fitted or bonded after press-fitting.
Are fixed to the motor circuit board 28. Other configurations are the same as those in the first embodiment, and a description thereof will not be repeated. According to this embodiment, even when the number of stator pins is small due to the number of slots in the stator, or when the strength due to soldering is insufficient, sufficient strength for fixing the stator to the motor circuit board can be obtained.

Third Embodiment FIGS. 5 to 7 show a main part of a third embodiment of the present invention. Note that the same reference numerals as those in the first embodiment denote the same parts. As shown in FIG. 5, in the present embodiment, the mold portion having the inner diameter of the stator 49 is made smaller than the outer diameter of the fixed sleeve 50, and the stator 49 is pressed into the outer diameter of the fixed sleeve 50. Further, as shown in FIG. 6, the deformation of the shallow groove for generating dynamic pressure can be suppressed by press-fitting the mold core into the non-groove portion of the fixed sleeve 50. Further, as shown in FIG. 7, by partially increasing the diameter of the portion to be pressed into the fixed sleeve 50 as shown by 52, the deformation of the inner diameter of the fixed sleeve due to the press-fitting of the stator can be further reduced. With such a configuration, the fixing of the motor circuit board of the stator in the first and second embodiments can be further strengthened, and the stator, the fixing sleeve, and the motor circuit board can be fixed respectively. Characteristics can be changed to suppress resonance.

[0014]

As described above, in the deflection scanning device according to the present invention, the positioning pin provided on the stator is fitted into the positioning hole formed on the motor circuit board to perform positioning of the stator. With the bottom surface of the stator in close contact with the motor circuit board, one end of an L-shaped stator pin arranged approximately equally in the circumferential direction of the mold core is fixed to the motor circuit board,
The stator can be firmly fixed to the motor circuit board, reducing vibration and noise even when the rotor unbalance is large or the cogging torque is large, and the number of parts and the process can be simplified. Therefore, an inexpensive and high-performance deflection scanning device can be realized. Further, in the present invention, the positioning pin is formed to have an outer diameter larger than the diameter of the positioning hole formed in the motor circuit board, and the positioning pin is press-fitted into the positioning hole or bonded after press-fitting. Accordingly, the stator can be firmly fixed to the motor circuit board even when the number of stator pins is small due to the number of slots in the stator or when the strength due to soldering is insufficient. Further, in the present invention, the stator can be more firmly fixed to the motor circuit board by pressing the mold core into the outer periphery of the fixing sleeve.

[Brief description of the drawings]

FIG. 1 is a main sectional view of a deflector according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a stator according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram of a deflection scanning device according to a first embodiment of the present invention.

FIG. 4 is a main sectional view of a deflector according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a main cross section of a deflector according to a third embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a main cross section of a deflector according to a modification of the third embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of a main cross section of a deflector according to a modification of the third embodiment of the present invention.

FIG. 8 is a main sectional view of a conventional deflector.

[Explanation of symbols]

 21: Optical box 28: Motor circuit board 29, 50: Fixed sleeve 30: Rotating shaft 31: Flange member 32: Rotating polygon mirror 33: Holding spring 34: Drive magnet 35, 48, 49: Stator 36, 37: Herringbone shape Groove 38: thrust plate 39: lubricating oil 40: stator core 41: mold core 42: stator pin 43-a, 43-b, 46: positioning pin 44: winding 45, 47: positioning hole 51: large diameter of fixed sleeve

Claims (5)

[Claims] A rotary shaft rotatably fitted to a fixed sleeve; a flange member fixed to the rotary shaft; a rotary polygon mirror fitted and supported on the flange member; A drive unit having a certain rotor magnet and a stator opposed thereto is provided, and a shallow groove for generating dynamic pressure is provided on the inner peripheral surface of the fixed sleeve or the outer peripheral surface of the rotating shaft,
In a deflection scanning device constituting a dynamic pressure bearing in which lubricating oil is interposed in a gap between the fixed sleeve and the rotating shaft, the stator is configured such that a winding is wound around a mold core, and the molding core is electrically connected to the winding. And L-shaped stator pins arranged approximately equally in the circumferential direction, and positioning of the stator by fitting positioning pins provided on the stator into positioning holes formed in the motor circuit board, A deflection scanning device, wherein a bottom surface of the stator is brought into close contact with the motor circuit board, and one end of the L-shaped stator pin is fixed to the motor circuit board. 2. The positioning pin has an outer diameter larger than a diameter of a positioning hole formed in the motor circuit board, and the positioning pin is press-fitted into the positioning hole or bonded after press-fitting. The deflection scanning device according to claim 1, wherein: 3. The deflection scanning device according to claim 1, wherein the mold core is configured to be pressed into an outer periphery of the fixed sleeve. 4. A position where the mold core is pressed into the outer periphery of the fixed sleeve is an outer peripheral portion of the fixed sleeve corresponding to a position on the inner peripheral surface of the fixed sleeve where a shallow groove is not provided. 4. The deflection scanning device according to claim 3, wherein: 5. The deflection scanning according to claim 3, wherein at least a part of the press-fitted portion on the outer periphery of the fixed sleeve is larger in diameter than a portion of the fixed sleeve that is not press-fitted. apparatus.