JP3407968B2 - Resonant optical deflector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonance type optical deflector for rotating and oscillating a reflecting mirror for scanning light in a scanner.

[0002]

2. Description of the Related Art In recent years, optical scanners for processing two-dimensional information such as images by rotating and oscillating a mirror at high speed have been widely used.

In the optical scanner, an elastic member is attached to the mirror or the like in order to rotationally oscillate the mirror at a high speed, and the resonance phenomenon of the elastic member is used to reduce the inertia of the mirror (hereinafter referred to as a resonant scanner). ) Is proposed. In this resonant scanner, when the elastic member switches the rotational vibration in the opposite direction, the reversing speed is improved and the inertia phenomenon is reduced by the resonance phenomenon. Therefore, in the resonant scanner, the mirror can rotate and vibrate at high speed, and the image information can be processed at high speed.

[0004]

In the resonant scanner, the mirror is mounted on the rotary shaft, and the motor is mounted on one end of the rotary shaft. Therefore, in the motor, the rotating shaft may be separated from the rotation center due to the action of the magnetic force, and as a result, the mirror is displaced together with the rotating shaft. That is, the scanning light reflected by the mirror is shaken with respect to the image information (hereinafter referred to as wobble). Therefore, by image processing,
There is an inconvenience that the expected high accuracy and high reproducibility cannot be obtained.

For example, as shown in FIG. 7, Y (yellow), M (magenta), C (cyan), K (black).
In the case of a device that reads out image information from a record carrier on which image information is recorded in the main scanning direction of the scanning light L and reproduces an image by superimposing the image information of Y, M, C, and K, by the wobble. Shift of scanning light L in the sub-scanning direction (width d)
As a result, the image information to be superimposed becomes inaccurate, and the reproduced image may have a color shift.

[0006] Therefore, in order to overcome this kind of drawback,
A structure has been devised in which a weight that functions as a balancer is provided on the other end side of a solenoid that incorporates a magnet and is fixed to one end of the rotary vibration shaft. That is,
A rotary vibration shaft formed of a prism is attached between the solenoid and the weight, and a mirror is fixed to the rotary vibration shaft.

However, in this structure, when the mirror is operated, even if there is a weight, the magnet of the solenoid is displaced and the rotary drive shaft is tilted, which may cause wobble.

The present invention has been made to solve this kind of problem, and an object of the present invention is to provide a resonance type optical deflector capable of processing image information with high precision in a resonant scanner.

[0009]

In order to achieve the above object, the present invention provides a scanner for processing two-dimensional information such as an image by rotationally oscillating a mirror mounted on a rotary shaft. A resonance type optical deflector for rotationally vibrating, a reflection type mirror for deflecting scanning light in a main scanning direction, a rotation shaft on which the reflection type mirror is mounted, and both ends of the rotation shaft, A center of gravity is located on the axis of the rotating shaft, a set of rotation driving means for driving the rotating shaft, and a resonance elastic member having one end attached to the rotating shaft and the other end attached to a support. And, when the rotary driving means rotationally vibrates the reflective mirror, the resonant mirror of the elastic member is used to rotationally vibrate the reflective mirror.

[0010]

In the resonance type optical deflector according to the present invention, since a pair of rotation driving means whose center of gravity is located on the axis of the rotation shaft is attached to each end of the rotation shaft, the rotation drive means drives the rotation. Even if the axis is tilted, that is, the surface is tilted, the tilt of the reflective mirror is suppressed. Therefore, the wobble of the scanning light is suppressed, and the image information can be processed with high accuracy.

Particularly, when each of the rotation driving means is a solenoid, the rotation shafts are displaced in parallel to the axial direction by driving the solenoids at both ends of the rotation shaft in synchronism with each other. The tilt of the shaft can be prevented. Therefore, the image information can be processed with high precision without generating wobble in the scanning light.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The resonance type optical deflector according to the present invention will be described in detail below with reference to the accompanying drawings with reference to preferred embodiments.

A resonant optical deflector 10 according to an embodiment of the present invention.
Includes a housing 12 having a cylindrical tube shape, as shown in FIG.
The housing 12 has an opening 14 that is cut out by approximately 180 ° along the circumference, and a mirror to be described later has this opening 14
The interior of the housing 12 is exposed to the outside.

A support 16 having an arcuate cross section is fixedly provided in the housing 12, and a first solenoid 18 which is a drive source of a vibrating shaft, which will be described later, serves as a rotation drive means in a lower portion of the housing 12. Is provided. The first solenoid 18 is shown in FIG.
As shown in FIG.
As shown in FIG. 3, a vibration shaft 26 made of a prism is attached to the magnet 24. And the vibration shaft 2
A mirror 28 having a flat reflecting surface is attached to an intermediate portion of 6 through a rib 27 so as to face the opening 14 of the housing 12. A second solenoid 18 a, which is substantially the same as the first solenoid 18, is provided on the upper end of the vibration shaft 26. The second solenoid 18a includes a magnet 24a like the first solenoid 18. In this case, the position of the center of gravity of the movable portion 32 including the mirror 28, the vibration shaft 26, and the rib 27 is set so as to coincide with the vibration center. In the solenoids 18 and 18a, the position 20 of each coil is
The magnets 24 and 24a are aligned in phase while the magnets a and 20b are aligned.

Leaf springs 34a, 34b and 36a, 3a and 3a, which are curved in a J shape, are provided near the upper and lower ends of the vibrating shaft 26.
One end of 6b is attached, and the leaf springs 34a, 3
The other ends of 4b and 36a, 36b are attached to the support 16. In this case, the J-shaped leaf spring 34a,
34b and 36a, 36b are arranged so as to intersect each other at a substantially right angle in the central portion thereof. Leaf springs 34a, 3
The crossing positions of 4b and 36a, 36b are arranged so as to substantially coincide with the position of the center of gravity of the movable portion 32.

The resonance type optical deflector 10 according to the present embodiment is basically constructed as described above. Next, its operation and effect will be explained. In this case, an example of an image scanning device to which the resonant optical deflector 10 is applied will be described.

First, when scanning a scanning object such as a document or a record carrier with scanning light, as shown in FIG. 2, a pair of solenoids 18 and coils 20a and 2a of a solenoid 18a are provided.
An alternating current is supplied from the outside in synchronization with 0b.
Thereby, the magnets 24, 2 of the solenoids 18, 18a
4a and the vibrating shaft 26 are swung, and the mirror 28 attached to the vibrating shaft 26 vibrates in the arrow direction (see FIG. 4). Therefore, the scanning light L incident on the mirror 28 is reflected by the mirror 28.
The image is read or recorded by being reflected and deflected by the scanning means and scanning the scanned object such as a document through a scanning lens (not shown).

At this time, the alternating current is supplied to the coils 20a and 20b of the solenoids 18 and 18a in synchronization with each other, and the phases of the magnets 24 and 24a are aligned, so that the coils 20a and 20b and the magnet 24 are aligned. , 24
Magnetic force acts on a. For example, the forces F1 and F2 as shown in FIG. 5 act on the coil 20a depending on the direction of the current in the portion parallel to the axial direction of the magnet, and as a result, the forces F1 and F2 are applied.
A force F3, which is a reaction force of the resultant force of F2, acts on the magnets 24, 24a. Further, by switching the alternating current, a force F3 'acts on the magnets 24, 24a on the opposite side.

Therefore, as shown in the schematic view of the resonance type optical deflector 10 (see FIG. 6), the forces F3 and F3 'act alternately on the magnets 24 and 24a to cause the magnets 24 and 24a to move to A, Displace in the B direction. However, in this case, the magnets 24, 24a are substantially identical solenoids 18,18.
Even if it is displaced parallel to the A and B directions in the presence of a, it does not tilt, and it is possible to prevent the mirror from tilting, that is, from causing surface tilt. Eventually, since the surface tilt of the mirror 28 is suppressed, the wobble of the scanning light L is suppressed, and the image information can be processed accurately.

[0020]

According to the resonance type optical deflector of the present invention,
The following effects can be obtained.

In the resonance type optical deflector in which the rotary vibrating means is attached to both ends of the rotary shaft, the tilt of the rotary shaft caused by the rotary vibrating means can be suppressed. Therefore, the surface tilt of the reflective mirror is suppressed, and the processing accuracy of the image information by the scanning light is improved.

Further, the rotary vibration means is a solenoid, and by driving the solenoids in synchronization with each other, it is possible to prevent the rotary shaft from tilting only by the parallel movement of the rotary shaft. Therefore, it is possible to process the image information by the scanning light with higher accuracy without causing the reflective mirror to tilt.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a resonance type optical deflector according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the configuration of a solenoid of the resonance type optical deflector according to the embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a resonant optical deflector according to an embodiment of the present invention.

FIG. 4 is a vibration state explanatory diagram of a mirror according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a force acting on a solenoid of the resonant optical deflector according to the embodiment of the present invention.

FIG. 6 is a schematic diagram of a resonant optical deflector according to an example of the present invention.

FIG. 7 is an explanatory diagram of a wobble state of scanning light according to a conventional example.

[Explanation of symbols]

10 ... Resonant optical deflector 18, 18a ...
Solenoids 20a, 20b ... Coil 24, 24a ...
Magnet 26 ... Vibration axis 28 ... Mirror

Claims (2)

(57) [Claims] 1. A scanner for processing two-dimensional information such as an image by rotationally vibrating a mirror mounted on a rotary shaft, which is a resonance type optical deflector for rotationally vibrating the mirror, wherein main scanning of scanning light is performed. A reflective mirror that deflects in a direction, a rotary shaft on which the reflective mirror is mounted, and a rotary shaft that is mounted on both ends of the rotary shaft and that has a center of gravity on the axis of the rotary shaft and drives the rotary shaft. A pair of rotation driving means, and a resonance elastic member having one end attached to the rotation shaft and the other end attached to a support, and the rotation driving means rotates and vibrates the reflective mirror. A resonance type optical deflector characterized by rotating and vibrating the reflection type mirror by utilizing a resonance phenomenon of an elastic member. 2. The resonance type optical deflector according to claim 1, wherein the rotation driving means are solenoids driven in synchronization with each other.