JPH0559418U - Light deflector - Google Patents

Abstract

(57) [Abstract] [Purpose] The objective is to reduce the number of parts and the number of assembling steps in order to reduce the cost of the rotary polygon mirror type optical deflection. In an optical deflector in which a rotary polygon mirror is mounted on an electric rotor rotatably provided by bearing means, a hub, a rotor case, a rotary polygon mirror, or a hub and a rotary polygon mirror are integrally formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary polygon mirror type optical deflector used in an optical scanning system of a laser beam printer.

[0002]

[Prior Art]

 A conventional rotating polygon mirror type optical deflector will be described with reference to FIG. A fixed shaft 9 and a shaft bush 8 are fixed to a printed circuit board 7 made of iron or a silicon steel plate on which the motor coil group 6 is mounted, and the fixed shaft 9 and the bush 8 are fitted and fixed by press fitting or the like. On the other hand, the rotor case 14 having the motor driving magnet 3 on the lower surface and the rotation speed signal generating magnet 4 fixed on the inside is fixed to the hub 15 which constitutes the motor rotor. Further, a pair of bearings 5 are provided on the inner circumference of the hub 15 so that there is no gap between the bearing 5 and the hub 15. When the bearing 5 is a rolling shaft, its inner ring is fixed to the fixed shaft 9 and its outer ring is rotatable with the hub 15. The electric motor rotor having the above-described structure is fitted into the fixed shaft 9, and is assembled to the electric motor stator by the washer 10, the elastic body 11, the shaft retaining ring 12 and the like, and a preload is applied downward. A rotating polygon mirror 16 is mounted on the upper surface of the step portion of the hub 15, and an elastic body O-ring 17 disposed on the upper surface of the rotating polygon mirror 16 is provided with a holding plate 18 having a substantially U-shaped cross section and a hub 15. The rotary polygon mirror 16 is pressed in the direction of the hub 15 by being pressed by the retaining ring 19 provided in the upper extension portion of, and is fixed so as not to move. A seal member 13 or the like is attached to the upper end opening of the hub 15 so that oil mist generated from the bearing 5 when the motor rotor rotates does not scatter in the direction of the rotary polygon mirror 16 through the opening. It is devised to be.

[0003]

[Problems to be solved by the device]

 The conventional rotary polygon mirror type optical deflector has the following problems. In the conventional example shown in FIG. 3, the rotary polygon mirror 16 and the components for fixing the rotary polygon mirror 16 include an elastic O-ring 17, a holding plate 18, a retaining ring 19, a hub 15 of the motor rotor, and a rotor case 14. Although it is composed of separate parts, considering the cost reduction of the rotating polygon mirror type optical deflector, the structure consisting of the above parts increases the number of parts, and the cost cannot be reduced due to the man-hours required for assembly. There was a problem.

[0004]

[Means for Solving the Problems]

 The present invention is intended to solve the above problems, and will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. An optical motor having a rotary polygon mirror mounted on a motor rotor rotatably provided by bearing means. In the deflector, a hub, a rotor case, and a rotary polygon mirror or a hub and a rotary polygon mirror are integrally formed.

[0005]

[Action]

 The motor rotor hub, rotating polygon mirror, and rotor case are integrally formed, and the magnet and bearing are fixed to make them rotatable. The electric motor rotor is mounted on a motor board rotor having a shaft bush and a fixed shaft fixed to a printed board on which a coil group is mounted, and is assembled while applying a preload by a washer, an elastic body, and a snap ring for the shaft.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. The same components as those of the conventional example described in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, a fixed shaft 9 and a bush 8 are fixed to a printed board 7 made of iron or a silicon steel plate on which the motor coil group 6 is mounted, and the fixed shaft 9 and the shaft bush 8 are fitted by press fitting or the like. Fixed. On the other hand, the motor rotor 1 is provided by integrally forming the hub 15, the rotor case 14, and the rotary polygon mirror 16 of the conventional example described in FIG. 3, and the motor rotor 1 includes a back yoke 2 and a motor drive. The rotating magnet 3 for generating a rotational speed signal is fixed to the lower surface, and the rotating magnet 3 for the rotation speed signal is fixed to the inside. A pair of bearings 5 are provided inside the electric motor rotor 1 so that there is no gap between the bearing 5 and the electric motor rotor 1. Further, when the bearing 5 is a rolling shaft, the inner ring is fixed to the fixed shaft 9, and the outer ring is rotatable with the motor rotor 1. The electric motor rotor 1 having the above-described structure is fitted into the fixed shaft 9, and is attached to the electric motor stator by the washer 10, the elastic body 11, the shaft retaining ring 12, and the like, and preload is applied downward. Also, a seal member 13 or the like is attached to the upper end opening of the electric motor rotor 1 so that the oil mist generated from the bearing 5 does not scatter through the opening when the electric motor rotor 1 rotates. It is devised. FIG. 2 shows another embodiment, in which the motor rotor 1 obtained by integrally forming the hub 15 and the rotary polygon mirror 16 of the conventional example described in FIG. 3 is used, and the back yoke 2 is replaced. It has the same configuration as that of FIG. 1 except that the rotor case 14 is used. In this case as well, since the configuration is almost the same as in the case of FIG. 1, the number of parts and man-hours are reduced, and the cost can be reduced.

[0007]

[Effect of the device]

 According to the present invention, a hub, a rotor case, and a rotary polygon mirror or a hub and a rotary polygon mirror are integrally formed to obtain an electric motor rotor, so that each mounting surface of the electric motor rotor and the rotary polygon mirror can be cut as in the conventional case. You don't have to. Further, the member for fixing the rotary polygon mirror, the elastic O-ring, the holding plate, and the retaining ring can be eliminated. Therefore, the man-hours for mounting the rotary polygon mirror can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment according to the present invention.

FIG. 2 is a sectional view of another embodiment according to the present invention.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols] 1 motor rotor 2 back yoke 3 motor driving magnet 4 rotation speed signal generating magnet 5 bearing 6 motor coil group 7 printed circuit board 8 shaft bush 9 fixed shaft 10 washer 11 elastic body 12 shaft retaining ring 13 Seal member 14 Rotor case 15 Hub 16 Rotating polygon mirror 17 Elastic body O-ring 18 Holding plate 19 Retaining ring

Claims (2)

[Scope of utility model registration request] 1. An optical deflector in which a rotary polygon mirror is mounted on a motor rotor rotatably provided by bearing means, wherein a hub, a rotor case and a rotary polygon mirror are integrally formed. 2. The optical deflector according to claim 1, wherein the hub and the rotary polygon mirror are integrally formed.