JPH02189729A - Optical system driver - Google Patents

Abstract

PURPOSE:To attain miniaturization and thin profile by constituting the optical system driver with an optical system incorporated with a holder, a ground plate incorporated with a yoke and a magnetic circuit with an opposite yoke removed thereof. CONSTITUTION:An aspherical objective lens 401 incorporated with a holder is made of glass or plastic or the like. A base 5 is fixed to a ground plate 701 formed incorporatedly with yokes 702a, 702b with pressing by means of a screw 26, magnets 601a, 601b are fixed opposite to the yokes 702a, 702b of the ground plate 701, and the yokes 702a, 702b of the ground plate 701 and the magnets 601a, 601b are placed along the outer circumference of the objective lens 401 and a so-called an opposite yoke is removed. Thus, miniaturization and thin profile is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is suitably used, for example, for driving an objective lens for light in an optical information recording/reproducing device. This invention relates to an optical system drive device.

[Conventional technology]

Generally, in order to accurately record and reproduce information in an optical information recording/reproducing device, focus control is used to control the distance between the objective lens and the information track position to prevent warping or wobbling of the information recording medium, such as a disk or card. In addition, it is necessary to perform track control in which the objective lens is controlled to follow the eccentricity or deviation of the information track.

For this purpose, it is necessary to support the objective lens so that it can move freely in the 7-orcus direction and in the 7-orcus direction.

Conventionally, methods for supporting an objective lens have been proposed, such as a method in which it is supported by two sets of parallel leaf springs in seven orcus directions and a track direction, respectively, a method in which it is supported by four thin metal rods, and the like.

A conventional example of an objective lens driving device is shown in which four thin metal rods are used as supporting means for the objective lens.

11 to 1d shown in FIG. 3 are thin metal rods.

The metal rod has appropriate elasticity. 21-2d are viscoelastic bodies installed around the thin metal rods 11-1d. Reference numeral 3 in the figure represents a holder for holding the objective lens 4. 5 is a base. 6m as shown in the diagram.

6b is a focus direction driving magnet. The focus direction driving magnets 6m and 6b are fixedly layered on the base plate 7 so as to face each other. A yoke 8 in the focus direction is fixed to the center of the main plate 7.

Also, on the top of the focus direction driving magnets 6m and 5b,
A focus direction yoke plate 9 is fixedly provided. The center of the focus direction yoke plate 9 has a hole 10 into which a circular through hole is inserted. Also.

Holder 3 tiger, stopper 1 that controls movement in the evening direction
1 is fixed on the yoke plate 9 on the opposite side to the magnet 6as6b.

Then, the base 5 described above is fixed to the side surface to which the focus direction yoke plate 9, the focus direction driving magnet 6b, and the ground plate 7 are fixed.

Further, track direction yoke support stands 12m and 12b are fixed to the upper surface of the focus direction yoke plate 9 so as to face each other. Track direction yoke 13&.

13b is fixed so as to face the track direction yoke supports 12a and 12b. And track direction yoke 1
31 has a tiger and a magnet 14 for driving in the evening direction.

The track direction yoke 13b is provided with track direction drive magnets 14e and 14d.

Further, as shown in FIG. 1, a cylindrical seven orcus direction drive coil 15 is provided at the bottom of the holder 3. Track direction driving coils 16am16b are provided on two opposing side surfaces of the holder 3. The aforementioned metal rod 1aslb+1 is attached to both other side surfaces of the holder 3.
a+1d Ninth wire board to fix gold 25m, 25
b, and one of the side surfaces includes a reflector 17 for detecting relative position in the track direction (hereinafter referred to as track reflector) and a reflector 18 for detecting relative position in focus direction (hereinafter referred to as focus reflector). A photoreflector 19 (hereinafter referred to as a relative position sensor in the track direction) is mounted opposite the track reflector 17 and the seven-occasion reflector 18 as a relative position sensor in the track direction.
A photo reflector 20 (hereinafter referred to as a focus sensor board) is provided as a relative position sensor in the focus direction.The track sensor 19 is fixed to a track sensor board 211C, and the track sensor board 21 is a , is fixed to a track sensor support 22.The focus sensor 20 is fixed to a focus sensor substrate 23, and the focus sensor substrate 23 is fixed to a focus sensor support 24.The track sensor support 22
The focus sensor support base 24 is fixed to the upper surface of the protrusion on one side of the base 7 described above.

[Problem to be solved by the invention]

However, in the conventional example described above, the number of parts constituting the device is large, and a relative position sensor is also installed to achieve high-speed access, so the optical system drive device inevitably becomes large in size. This type of optical system drive device is easy to disassemble and is a good friend.) CD
When used for applications such as the above, the above-mentioned conventional devices are not suitable because high-speed access and small size and thin devices are generally required.

〔the purpose〕

The present invention has been made in view of the above-mentioned problems of the prior art), and its purpose is to provide an optical system drive device that can be made smaller and thinner.

[Means to solve the problem]

According to the present invention, the above-mentioned object includes an optical system in which a holder is integrated, a base plate in which a yoke is integrated, a base fixed to the yoke, and one end fixed to the base and another layer. This is achieved by an optical system driving device having an elastic support member fixed to the optical system and a driving means for driving the optical system.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the present invention will be described specifically and in detail based on the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of the optical system driving device of the present invention. In addition, in the following explanation.

Members having the same functions as the nine members shown in the conventional example will be designated by the same reference numerals, and their explanation will be omitted.

In FIG. 1, 401 is an aspherical objective lens that is integrally molded with the holder. The lens 401 is made of glass, glass, resin, or the like. A focus drive coil 151 is located on the side of the objective lens 1”401.
The focus drive coil 151 is wound with a flat, flat drive coil 161b fixed to a part of the side surface of the focus drive coil 151. A flat track drive coil 161m (not shown) is fixed at a position facing the track drive coil 161b. Thin metal rods 1a to ld (one layer not shown is a wire substrate 25m, 25bK fixed to the objective lens 401)
Fi! The other end is fixed to the base 5. Further, in this embodiment, the metal wires la to 1d also function as lead wires for the focus drive coil and the track drive coil.

The base 5 is fixed with screws 26 to a base plate 701 which is integrally pressed with the yoke parts 702m and 702b.

Magnets 601m and 601b are the yoke part 702 of the main plate 701
m.

It is fixed opposite to 702b. The slotted portions 702m, 702b of the base plate 701 and the magnets 601m, 601b are shaped to follow the outer periphery of the objective lens e401 as shown. Further, the viscoelastic bodies 2a to 2d are made of the thin metal @ l
a to ld (held on the periphery (not shown) to produce an appropriate damping effect. In this way, the objective lens integrated with the holder, the base plate integrated with the yoke, Also, by eliminating the so-called opposing yoke, it is possible to construct a compact and lightweight optical system drive device with fewer parts.In this embodiment, the symmetry of the device shape and the seven orcus Due to the symmetry of the point of application of the driving force and the drag driving force, and appropriate damping characteristics, rolling mode (moving part centered on the axis perpendicular to both axes in the track direction and the door orifice direction (i.e., the rolling rotation axis)) It exhibits good vibration characteristics with suppressed rotation.

Further, if it is necessary to suppress the rolling mode and improve the time running performance even more than the above embodiment, this can be achieved in the following manner. That is, this is done by integrally molding the viscous bodies 21 to 2d shown in FIG. 1 and the base 5. In FIG. 2, the solid line shows the vibration characteristics in the track direction of the optical system driving device explained in the first factor, and the broken line shows the track direction when the viscoelastic body and the base are integrally molded.

Let us show the vibration characteristics in the evening direction.

〔Effect of the invention〕

As explained above in detail and specifically, the present invention is made up of an optical system integrally molded with a holder, a main plate integrally molded with a yoke, and a magnetic circuit from which the opposing yoke is removed. # type optical system drive device can be provided. Furthermore, by supporting the optical system with four thin elastic bodies and a viscoelastic body surrounding them, damping is appropriately effective, rolling mode is suppressed, and good vibration characteristics can be obtained. Furthermore, by integrally molding the viscoelastic body and the base, damping is even more effective, rolling mode is suppressed, and time running can be realized. It is possible to provide an optical system drive device that is suitably used in systems that require high nt degree control, such as recording and reproducing devices.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an embodiment of the optical system driving device of the present invention, Fig. 2 is a graph showing the vibration characteristics in the track direction of the optical system driving device of the present invention, and the third eldest is a conventional objective lens. Figure 6 is an exploded perspective view showing the drive device. @: i unit, φ1: anti-conductor lens molded with - and -W, 701: main plate integrally molded with yoke - Agent: Patent attorney Minoru Yamashita Sensitivity (dB)

Claims (1)

[Claims] (1) An optical system with a holder integrally molded, a base plate with a yoke integrally molded, a base fixed to the yoke, one end fixed to the base and the other end fixed to the optical system. An optical system driving device, comprising an elastic support member and a driving means for driving the optical system.