JPH04151619A - Rotary mirror device for tracking - Google Patents

Abstract

PURPOSE:To obtain a rotary mirror device for tracking which responds excellently and accurately and is miniaturized by bending a thin leaf spring between its plane part and a fitting part for a thin leaf spring supporting member and forming twist parts for rotation, and making the thin leaf spring serve a also as wiring plate for a moving coil. CONSTITUTION:The thin leaf spring 12 consists of a fitting part 12a for a mirror holding member 11, two fitting parts 12b for supporting the thin leaf spring 12, and two twist parts 12c for rotating a reflecting mirror 10. The thin leaf spring 12 is a flexible printed wiring board based upon a high polymer material such as polyimide and polyester, one wiring pattern 17 each for right and left sides is formed from the fitting part 12a for the mirror holding member 11 to the fitting part 12b for the thin leaf spring support member through the twist part 12c, and the terminal 13a of the driving coil is connected to a wiring pattern 17. Consequently, the stability of rotation is improved, faster operation is possible, and the space for wiring is reduced to make the size small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating mirror device for tracking used in an optical head of an optical disc device, for example, to make a light beam spot follow a track of an optical disc. be.

[Prior Art] FIG. 5 is a perspective view of a conventional rotating mirror device for tracking, in which a reflecting mirror 1 is supported by a thin plate spring 3 via a mirror holding member 2, and a driving coil 4 fixed to the back surface thereof. It is rotationally driven by the magnetic force acting between the yoke 5 and the yoke 5. Here, the wiring material 6 to the drive coil 4 is introduced through a hole 5a provided in the yoke 5. By passing a current through the drive coil 4 through the wiring material 6, the reflecting mirror 1 is slightly rotated in the vertical direction. The angle is thin plate spring 3
It is determined by the balance between the elastic force and the magnetic force acting on the drive coil 4, and is approximately proportional to the magnitude of the current.

[Problems to be Solved by the Invention] However, in this conventional example, a space and a hole 5a for only the wiring material 6 are required for wiring to the drive coil 4 for rotating the reflecting mirror 1. Further, there is a problem in that the reaction force due to the elasticity and inertia of the wiring material 6 is transmitted to the reflecting mirror 1, which adversely affects the frequency characteristics and neutrality of tracking.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a tracking rotating mirror device that has a good response, is accurate, and is smaller in size.

[Means for Solving the Problems] In order to achieve the above-mentioned object, a tracking rotating mirror device according to the present invention includes a tracking rotating mirror device that drives a light beam spot in the radial direction of an optical disk of an information recording medium. A mirror device in which a mirror holding member for holding a reflecting mirror is rotatably supported by a thin plate spring,
The flat part of the thin leaf spring is overlapped with the reflective surface of the reflective mirror, and the thin leaf spring is constricted between the flat part and the attachment part to the thin leaf spring support member to form the torsion part for the rotation. However, the thin plate spring is characterized in that it also serves as a wiring board for a movable coil for rotation.

[Function] The rotating mirror device for tracking having the above configuration has the following features:
This is because the thin leaf spring also serves as a wiring board.

Unnecessary external force is not applied to the mirror holding member that holds the reflecting mirror, and the rotational stability of the reflecting mirror is improved, and at the same time, the space for wiring is reduced, resulting in miniaturization.

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 to 4.

Figure 1 is a perspective view of the first embodiment, Figure 2 is a sectional view thereof, and Figure 3 (at is a perspective view of the driven part, lbl is a side view, and (cl is a partially sectional plane). (dl is a rear view) The reflective mirror 10 is held by attaching the back surface of its reflective surface to a mirror holding member 11, and the mirror holding member 11 is suspended and held by a thin plate spring 12.Mirror A drive coil 13 is installed around the side surface of the holding member 11.
A yoke 14 and a relay yoke 15 are provided on both sides of the coil 13 so as to sandwich the coil 13 therebetween, and a permanent magnet 16 is interposed between the yokes 14 and 15. As shown in FIG. 3 (dl), the thin leaf spring 12 has a mounting portion 12a for attaching to the mirror holding member 11, two mounting portions 12b for supporting the thin leaf spring 12, and two mounting portions for rotating the reflecting mirror 10. This twisting portion 12c
The mounting part 12a and the mounting part 12b are constricted to create a bridge state, and the torsional rigidity is changed by changing the radius of the torsion part 12c and the plate thickness of the thin plate spring 12, and - the next torsional resonance frequency is changed. The rotation of the 0-reflection mirror lO, which is said to be possible to It becomes the center of rotation. The thin plate spring 12 is a flexible printed wiring board based on a polymeric material such as polyimide or polyester, and has a mounting portion 12 on the mirror holding member 11.
Wiring patterns 17 are formed one on each side from a to the left and right through the torsion portion 12c to the attachment portion 12b to the thin plate spring support member, and the terminal 13a of the drive coil 13 is connected to the wiring pattern 17.

The reflective mirror 10 is rotated by passing a current between the wiring patterns 17 on the two fixed mounting parts 12b, and when the current is passed through the drive coil 13 via the terminal 13a, the reflecting mirror A force is generated in a direction perpendicular to the reflecting surface of the mirror 10, but this force is restrained by the thin plate spring 12 via the mirror holding member 11, so this force is
This is converted into a moment force centered on the torsion portion 12c of the thin plate spring 12, and the reflecting mirror 10 rotates around the torsion portion 12c.

FIG. 4 shows a second embodiment, in which ia) is a perspective view of the driven part, (bl is a side view, fcl is a partially sectional plan view, and (dl is a rear view). In the example, thin plate spring 1
2 is divided into two parts, and is a thin plate spring made of a highly conductive metal spring material such as phosphor bronze or beryllium copper.
”.The thin leaf springs 12° and 12° are arranged symmetrically, and each mounting portion 12a is attached to the mirror holding member 1.
1, the terminal 13a of the drive coil 13 is connected to the attachment part 12a, and the thin plate spring 21 itself is used as a wiring material. Therefore, by drawing a current from the attachment portion 12b, the current can be supplied to the drive coil 13 via the terminal 13a.

In either embodiment, since the mirror holding part I'll receives elastic force only from the thin plate spring 12, control is easy and there is almost no need to consider the space for the wiring material.

[Effects of the Invention] As explained above, in the rotating mirror device for tracking according to the present invention, the rotational stability is improved by using the thin plate spring that supports the mirror as a wiring material to the moving coil.
Faster operation is possible, and at the same time space for wiring is reduced and the device is more compact.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the rotating mirror device for tracking according to the present invention, where Figure 1 is a perspective view of the first embodiment, Figure 2 is a sectional view thereof, and Figure 3 ( al is a perspective view of the driven part, tbl is a side view, (c) is a partially sectional plan view, fd) is a rear view, and Figure 4 (at is a perspective view of the driven part of the second embodiment) (bl is a side view, (cl is a partially sectional plan view, (di is a rear view, and FIG. 5 is a perspective view of a conventional example. Reference numeral 10 is a mirror, and 11 is a mirror holding member. , 12.12
° 12''' is a thin plate spring, 13 is a drive coil, and 17 is a wiring pattern. Patent applicant Canon Co., Ltd. Figure 1 Figure 3 (a) (b) (C) (d) Figure 4 (b) (C) (d)

Claims (1)

[Claims] 1. A rotating mirror device for tracking that drives a light beam spot in the radial direction of an optical disk of an information recording medium, in which a mirror holding member that holds a reflecting mirror is rotatably supported by a thin plate spring, and The flat part is superimposed on the reflective surface of the reflective mirror, and the thin plate spring is constricted between the flat part and the attachment part to the thin plate spring support member to form the torsion part for the rotation, and the thin plate A rotating mirror device for tracking, characterized in that a spring also serves as a wiring board for a moving coil for rotation.