JPH0543118U - Rotating polygon mirror for optical deflector - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Adhesion and mechanical coupling by clamp members are used together to simplify assembly work, reduce the number of parts, and provide a high-performance rotary polygon mirror at low cost. .. [Structure] Reflector mounting surfaces 4A, 4B, 4 on a mirror base 1 that are inclined by a required angle with respect to a rotation axis center line P and are equally divided from the rotation axis at equal azimuth angles.
C, using the minimum amount of adhesive, three fan-shaped reflectors 3A,
Temporarily fix 3B and 3C respectively. Next, a star-shaped washer-shaped second clamp member 6 having three clamping tabs 9A, 9B, and 9C on the outer periphery, and three clamping tabs on the circumference of an annular member having a U-shaped cross section. 8A, 8B,
With the first clamp member 5 provided with 8C, the reflecting mirror 3
Formally fix A, 3B and 3C. Further, the balance weight is arranged in the annular groove portion 8D of the first clamp member 5 to adjust the dynamic balance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a rotary polygon mirror used in an optical deflector used in, for example, a stationary bar code scanner.

[0002]

[Prior Art]

 A conventional example of this type of rotary polygon mirror will be described with reference to FIG. In the figure, reference numeral 10 indicates a mirror base member, and a pyramid-shaped reflecting mirror mounting surface is formed from a cylindrical aluminum alloy by means of cutting or the like. Further, symbols 11A, 11B and 11C indicate substantially fan-shaped reflecting mirrors matching the shape of the reflecting mirror mounting surface, and are fixed to the respective reflecting mirror mounting surfaces of the mirror base member 10 by adhesion. . In addition, reference numeral 12 indicates a shaft that is erected at the center of the mirror base member 10, and is connected to a rotating means such as a motor (not shown) or is also used as a rotating shaft of the rotating means. For example, the laser light L is incident on the reflecting mirror 11A from the rotation axis direction of the rotating polygon mirror having the above-described configuration, and the rotating polygon mirror is driven to rotate by the motor (not shown). The plane perpendicular to the axis can be repeatedly scanned by a required angle θ. In the case of the conventional example, since the reflecting mirror has a structure of three pieces, the laser beam L is scanned by about 120 degrees.

[0003]

[Problems to be solved by the device]

 However, in the conventional rotary polygon mirror, the reflecting mirrors 11A, 11B, and 11C are fixed to the mirror base member 10 by adhesion, so that there is a problem described below. (1) It is necessary to strictly control the bonding conditions so that the reflecting mirror does not peel off and scatter due to the centrifugal force generated by the rotation of the rotating polygonal mirror, and the adhesive is used to ensure a large bonding area. By applying to the entire surfaces of the mirrors 11A, 11B, 11C, excess adhesive easily adheres to the reflecting mirror surface. (2) It is necessary to separately add a mechanism for correcting the deterioration of the dynamic balance due to the processing accuracy error of each of the reflecting mirrors 11A, 11B and 11C.

[0004]

[Means for Solving the Problems]

 The present invention has been made in order to solve the above-mentioned problems, and it is made up of three fans that are inclined at a required angle with respect to the rotation axis center line P and are equally divided from the rotation center axis at equal azimuth angles. In a rotary polygon mirror for an optical deflector, which is composed of reflecting mirrors 3A, 3B, and 3C that form a mold, each of the reflecting mirror mounting surfaces 4A, 4B, and 4C of the mirror base member 1 that forms a pyramid shape has three outer peripheral portions. A second clamp member 6 having a star-shaped washer shape having claws 9A, 9B, 9C for clamping, and claws 8A, 8B, 8C for clamping at three places on the circumference of an annular member having a U-shaped cross section. With the first clamp member 5 provided, the reflecting mirrors 3A, 3B and 3C are mounted and fixed.

[0005]

[Action]

 According to the present invention, the reflecting mirrors 3A, 3B, 3C are mounted on the respective reflecting mirrors by using the tabs 8A, 8B, 8C, 9A, 9B, 9C of the first clamp member 5 and the second clamp member 6. Since it can be fixed to the surfaces 4A, 4B and 4C, the claws 8A, 8B, 8C, 9A, 9B and 9C can receive the centrifugal force generated by the rotation of the rotary polygon mirror. Furthermore, a required balance weight can be applied to the groove formed in the U-shaped cross section of the first clamp member 5.

[0006]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway exploded perspective view of an embodiment of a rotary polygon mirror according to the present invention. In the figure, symbol 1 is a pyramidal reflector mounting surface 4A, for example, made of a cylindrical aluminum alloy by cutting or the like. 4B and 4C are mirror base members. Reference numeral 2 indicates a shaft erected in the center of the mirror base member 1, which also serves as the rotation shaft of a motor (not shown). Symbols 3A, 3B, and 3C indicate reflecting mirrors, and in this embodiment, one surface of the glass plate is coated with a dielectric multilayer film and is formed in a fan shape. Reference numeral 5 indicates a first clamp member, which is formed by pressing a spring steel into an annular groove portion 8D that opens in the axial direction of the shaft 2 and claws 8 for reflecting mirror clamping at positions that divide the circumference into three equal parts. A, 8B and 8C are formed. In the figure, the first clamp member 5 is shown in a perspective view with a part thereof cut away. Further, in the figure, symbol 6 indicates a second clamp member, which is formed by pressing from spring steel into a washer shape having claws 9A, 9B, 9C for reflecting mirror clamps at three locations on the outer circumference. . In addition, symbol 7 indicates a screw for fitting the screw portion 2A formed at one end of the shaft 2 to fix the second clamp member 6. The assembly of the rotary polygon mirror having the above-described configuration is performed by the following procedure. (1) The shaft 2 is pressed into the hole in the central portion of the mirror base member 1 or set up by shrink fitting. (2) After applying a small amount of adhesive to the reflecting mirror mounting surfaces 4A, 4B, 4C, the reflecting mirrors 3A, 3B, 3C are bonded and temporarily fixed. (3) After mounting the first clamp member 5 on the mirror base member 1 from above the reflecting mirrors 3A, 3B, 3C, it is fixed to the mirror base member 1 by press fitting or adhesion. (4) The second clamp member 6 is fitted on the tops of the reflecting mirrors 3A, 3B, 3C and then fixed by the screw 7. (5) Rotate the shaft 2 as a rotation reference, and correct the dynamic balance with a balancing machine or the like. This work is performed by disposing the balance weight in the annular groove portion 8D formed in the first clamp member 5.

[0007]

[Effect of the device]

 As described in detail above, according to the present invention, the bonding strength between the reflecting mirror and the mirror base member and the mechanical coupling method using the first clamp member and the second clamp member are combined. Since the amount of the adhesive can be reduced without lowering the adhesiveness, it is possible to prevent the reflection mirror surface from being contaminated by the protrusion of the adhesive. Further, since it is not necessary to position the reflecting mirror and the mirror base member while the adhesive is being hardened, the assembling work can be simplified. In addition, since it also serves as a structure for balance correction, the number of parts can be reduced. Therefore, the cost of the optical deflector using the present rotary polygon mirror can be reduced, and the bar code scanner or the like can be inexpensively supplied.

[Brief description of drawings]

FIG. 1 is a partially cutaway exploded perspective view showing an embodiment of a rotary polygon mirror according to the present invention.

FIG. 2 is a perspective view showing a conventional rotating polygon mirror.

[Explanation of symbols]

 1, 10 Mirror base member 2, 12 Shaft 3A, 3B, 3C, 11A, 11B, 11C Reflecting mirror 4A, 4B, 4C Reflecting mirror mounting surface 5 First clamp member 6 Second clamp member 8A, 8B, 8C, 9A, 9B, 9C claws

Claims (1)

[Scope of utility model registration request] 1. Three fan-shaped reflecting mirrors (3A, 3B, 3A, 3B, 3A, 3B, 3A, 3B, each of which is inclined at a required angle with respect to a rotation axis center line P and equally arranged at equal azimuth angles from the rotation center axis.
In the rotary polygon mirror for an optical deflector constituted by 3C), each of the reflecting mirror mounting surfaces (4A, 4B, 4C) of the pyramid-shaped mirror base member (1) has three clamping claws (at the outer peripheral portion). 9A, 9B, 9C) having a star-shaped washer-shaped second clamp member (6),
The reflecting mirror (3A, 3B, 3C) is composed of a first clamp member (5) having clamp claws (8A, 8B, 8C) provided at three locations around the circumference of an annular member having a U-shaped cross section. Equipped with,
A rotating polygon mirror for an optical deflector characterized by being fixed.