JP3026683U - Mounting structure for polygon mirror - Google Patents

Abstract

(57) Abstract: A polygon mirror mounting structure is provided which can omit a balance adjustment work and can be easily mounted in a state where a core is aligned with a rotation driving member. A rotor 10 rotates integrally with a rotary shaft 8 in a laser scanning motor 2. The receiving portion 1008 is provided at the boundary between the fitting portion 1004 of the rotor 10 and the large diameter portion 1002.
Are formed. A recessed groove 26 is formed around the entire circumference of the fitting portion 1004, and the elastic member 30 is formed in the recessed groove 26.
Is attached. The polygon mirror 12 has a fitting portion 100.
4 is fitted in the central hole 1204, and is fixed to the rotor 10 via the receiving portion 1008 and the pressing member 14. When the fitting portion 1004 is fitted into the center hole 1204, the elastic member 30 is compressed by the inner peripheral portion of the center hole 1204, and the elastic member 30 is compressed by the concave groove 26 of the fitting portion 1004 and the center hole 1204.
The center of the polygon mirror 12 and the center of the rotor 10 are aligned with each other by making elastic contact with both inner peripheral portions of

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to a mounting structure for a polygon mirror used in a laser printer, a facsimile, or the like.

[0002]

[Prior art]

 For example, in a laser printer or a facsimile, a polygon mirror having a plurality of reflection surfaces formed on the outer periphery is rotated at high speed, and a light beam corresponding to image information is directed to the light receiving means such as a photosensitive drum or CCD by the reflection surface. It is reflected and scanned. The polygon mirror is removably attached to the rotation driving member, and the attachment is performed by fitting the fitting portion of the rotation driving member into the center hole of the polygon mirror and fixing the end surface of the polygon mirror around the center hole. Is placed on the receiving portion formed on the fitting portion, and the polygon mirror portion around the center hole is pressed against the receiving portion from the end surface opposite to the end surface placed on the receiving portion. .

[0003]

[Problems to be solved by the device]

 On the other hand, if the center of the polygon mirror is displaced with respect to the fitting portion, the polygon mirror rotates at a high speed, causing vibration, which causes problems such as noise and deterioration of print quality. Generally, the fitting portion and the center hole of the polygon mirror are fitted with each other by using g4 or g5 in the fitting portion and H6 or H7 in the center hole. If it is 16 mm, there will be a minimum gap of 6 μm and a maximum gap of 22 μm between the outer peripheral portion of the fitting portion and the inner peripheral portion of the center hole.

Therefore, even when the fitting portion and the center hole are formed within the respective tolerance ranges, the polygon mirror is eccentrically attached to the fitting portion within the tolerance range, and the eccentricity amount thereof is increased. Depending on the situation, vibration or the like may occur as described above. Therefore, conventionally, balance adjustment work such as embedding a weight in the surface of the rotary drive member facing upward is performed, but this balance adjustment work has a problem that it takes time and labor. The present invention has been devised in view of the above circumstances, and an object of the present invention is to minimize the balance adjustment work, prevent misalignment due to vibration, shock, etc. An object of the present invention is to provide a polygon mirror mounting structure that can be easily mounted in a state where the core is aligned with the rotation driving member.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is to fit a fitting portion of a rotation driving member into a center hole of a polygon mirror, and hold a polygon mirror portion around the center hole by a pressing member, and a receiving portion provided in the fitting portion. The structure is such that the polygon mirror is attached to the rotary drive member by pressing it to the outer peripheral portion of the fitting portion and the inner peripheral portion of the center hole of the polygon mirror. It is characterized in that an elastic member that makes elastic contact is arranged.

Further, the present invention is characterized in that a concave groove continuous in the circumferential direction is formed on an outer peripheral portion of the fitting portion, and the elastic member is arranged in the concave groove. Further, the present invention is characterized in that the pressing member is composed of a pressing spring attached to the fitting portion side. Further, the present invention is characterized in that the elastic member is formed by extending an elastic material such as rubber in an annular shape. Further, the present invention is characterized in that the elastic member is formed by bending a metal wire rod or a belt member and extending in an annular shape. Further, in the present invention, the rotation driving member includes a rotation shaft rotatably supported by a base frame of a laser scanning motor and a rotor fixed to the rotation shaft, and the fitting portion and the receiving portion are provided. Is formed on the rotor. Further, the present invention is characterized in that the pressing member is attached to a rotary shaft portion protruding from the rotor.

According to the present invention, when the polygon mirror is incorporated in the rotation driving member, the elastic member elastically contacts both the outer peripheral portion of the fitting portion and the inner peripheral portion of the center hole of the polygon mirror, so that the elastic member is aligned with the center of the polygon mirror. The center of the fitting portion is automatically matched by the elastic member.

[0008]

[Embodiment of device]

 An embodiment in which the present invention is applied to a laser scanning motor will be described below with reference to the drawings. FIG. 1 is a sectional front view of the laser scanning motor, FIG. 2 is a plan view of the same, and FIG. 3 is an enlarged sectional view of the same part. Reference numeral 2 is a laser scanning motor, and the laser scanning motor 2 is composed of a base frame 4, a circuit board 6, a rotary shaft 8, a rotor 10, a polygon mirror 12, a pressing member 14, and the like.

The base frame 4 is composed of a flat plate portion 402 and a cylindrical bearing portion 404 bulged in a part of the flat plate portion 402, and bearings 16 are attached above and below the bearing portion 404. . The rotary shaft 8 is rotatably and vertically supported by the upper and lower bearings 16, and a stopper 18 is provided at the lower end of the rotary shaft 8 to prevent the rotary shaft 8 from moving upward. The circuit board 6 is arranged on the flat plate portion 402, and the rotor 10 is arranged on the circuit board 6.

The rotor 10 is composed of a large diameter portion 1002 and a fitting portion 1004 having a diameter smaller than the large diameter portion 1002, and a hole 1006 is formed at the center of the rotor 10. The rotary shaft 8 portion protruding upward from the bearing portion 404 is fitted and fixed in the hole 1006, and the rotor 10 rotates integrally with the rotary shaft 8. An annular receiving portion 1008 is formed at a boundary between the fitting portion 1004 and the large diameter portion 1002 of the rotor 10 as shown in FIG. 3, and the polygon mirror 12 connects the fitting portion 1004 and the receiving portion 1008. It is attached to the rotor 10 via the rotor 10, and in the embodiment, the rotor 10 corresponds to the rotation driving member. The lower surface of the large-diameter portion 1002 faces the circuit board 6, the magnet 20 is arranged on the lower surface of the large-diameter portion 1002 on the inner side in the radial direction, and the magnet 20 is provided on the portion of the circuit board 6 facing the magnet 20. Correspondingly, the coil 22 is annularly arranged, and the magnet 20 and the coil 22 constitute a motor. In the figure, reference numeral 24 indicates an IC for controlling the current flowing through the coil 22.

A concave groove 26 is formed around the entire outer peripheral portion of the fitting portion 1004, and an annular elastic member 30 is attached to the concave groove 26. In this embodiment, the elastic member 30 is formed of an elastic material such as rubber extending in an annular shape. When the center hole 1006 of the polygon mirror 12 is fitted in the fitting portion 1004, a concave groove is formed. 26 and the inner peripheral portion of the center hole 1006 are elastically contacted with each other.

The polygon mirror 12 has a regular hexagonal shape in plan view, and has six reflecting surfaces 1202 formed on the outer periphery thereof and a central hole 1204 formed at the center thereof. To attach the polygon mirror 12, first, the fitting portion 1004 is fitted into the central hole 1204, and the end surface around the central hole 1204 is placed on the receiving portion 1008. Next, the pressing member 14 is attached to the upper end of the fitting portion 1004, and by this pressing member 14, the center hole 1204 of the center hole 1204 is formed at the end surface portion of the polygon mirror 12 opposite to the end surface placed on the receiving portion 1008. The peripheral portion is pressed against the receiving portion 1008. In the embodiment, the pressing member 14 is a pressing spring formed of a disk-shaped spring plate, and is attached to the fitting portion 1004 by the stop ring 1402. As a result, the polygon mirror 12 can be mounted integrally with the rotor 10 in a rotatable state.

According to this embodiment, when the fitting portion 1004 is fitted into the center hole 1204 of the polygon mirror 12, the elastic member 30 is compressed by the inner peripheral portion of the center hole 1204, and the elastic member 30 is fitted. It makes elastic contact with both the concave groove 26 of the joining portion 1004 and the inner peripheral portion of the central hole 1204. Then, due to the reaction force of the elastic member 30, the center of the polygon mirror 12 and the center of the fitting portion 1004 are aligned, in other words, the center of the polygon mirror 12 and the center of the rotor 10 are aligned. Then, in this state, the portion around the center hole 1204 of the polygon mirror 12 is pressed against the receiving portion 1008 by the pressing member 14 and fixed.

That is, according to the present embodiment, when the polygon mirror 12 is attached to the rotor 10, the centers of the both are automatically aligned and fixed by the pressing member 14 in the aligned state. Therefore, the polygon mirror 12 can be attached to the rotor 10 with high accuracy and easily, the balance adjustment work can be minimized, and the misalignment due to vibration, impact, etc. can be prevented.

FIG. 4 is an enlarged plan view of a polygon mirror portion showing a modified example of the elastic member. In this modification, an elastic member 30 'is configured by winding a wire made of a metal such as spring steel or a band in a circular shape while bending the elastic member 30'. It is arranged between the outer peripheral portion of 004 and the inner peripheral portion of the central hole 1204 of the polygon mirror 12. Even with such an elastic member 30 ′, the elastic member 30 ′ elastically contacts both the outer peripheral portion of the fitting portion 1004 and the inner peripheral portion of the center hole 1204, and the polygonal force is generated by the reaction force of the elastic member 30 ′. The center of the mirror 12 and the center of the fitting portion 1004 are aligned.

In the embodiment, the case where the elastic member is provided in the groove on the outer peripheral side of the fitting portion has been described. However, the groove is provided on the inner peripheral side of the center hole of the polygon mirror, and the elastic member is provided in this groove. You may make it fit.

[0017]

As is apparent from the above description, according to the present invention, the fitting portion of the rotation driving member is fitted in the center hole of the polygon mirror, and the polygon mirror portion around the center hole is fixed by the pressing member. The structure is such that the polygon mirror is attached to the rotation driving member by pressing it on the receiving portion provided in the fitting portion, and the polygon mirror is attached between the outer peripheral portion of the fitting portion and the inner peripheral portion of the center hole of the polygon mirror. An elastic member that is in elastic contact with both the outer peripheral portion and the inner peripheral portion is arranged. Therefore, when the polygon mirror is incorporated in the rotary drive member, the center of the polygon mirror and the center of the fitting portion are automatically aligned with each other by the elastic member. Therefore, the polygon mirror can be easily attached, and since the center of the polygon mirror and the center of the fitting portion are aligned with each other, the balance adjustment work is minimized and the center due to vibration, impact, etc. is minimized. The present invention is suitable for use in laser printers and facsimiles because it can prevent misalignment and does not generate vibration even when it can be rotated at high speed.

[Brief description of drawings]

FIG. 1 is a sectional front view of a laser scanning motor.

FIG. 2 is a plan view of a laser scanning motor.

FIG. 3 is an enlarged cross-sectional view of a main part of a laser scanning motor.

FIG. 4 is an enlarged plan view of a polygon mirror portion showing a modified example of an elastic member.

[Explanation of symbols]

 2 laser scanning motor 4 base frame 6 circuit board 8 rotating shaft 10 rotor 12 polygon mirror 14 holding member 26 concave groove 30, 30 'elastic member

Claims (7)

[Scope of utility model registration request] 1. A polygon mirror is formed by fitting a fitting portion of a rotation driving member into a center hole of the polygon mirror, and pressing a polygon mirror portion around the center hole by a holding member against a receiving portion provided in the fitting portion. A structure for attaching a mirror to a rotation driving member, wherein an elastic member elastically contacting both the outer peripheral portion and the inner peripheral portion is provided between the outer peripheral portion of the fitting portion and the inner peripheral portion of the center hole of the polygon mirror. The polygon mirror mounting structure is characterized by being arranged. 2. The polygon mirror mounting structure according to claim 1, wherein a recessed groove that is continuous in the circumferential direction is formed on the outer peripheral portion of the fitting portion, and the elastic member is disposed in the recessed groove. 3. The polygon mirror mounting structure according to claim 1, wherein the pressing member is composed of a pressing spring attached to the fitting portion side. 4. The polygon mirror mounting structure according to claim 1, wherein the elastic member is formed by elastically extending an elastic material such as rubber in an annular shape. 5. The attachment structure for a polygon mirror according to claim 1, wherein the elastic member is formed by bending a metal wire rod or belt member and extending in an annular shape. 6. The rotation driving member includes a rotation shaft rotatably supported by a base frame of a laser scanning motor and a rotor fixed to the rotation shaft, and the fitting portion and the receiving portion are the same. The polygon mirror mounting structure according to claim 1, which is formed on a rotor. 7. The mounting structure for a polygon mirror according to claim 6, wherein the pressing member is attached to a rotary shaft portion protruding from the rotor.