JPS60160059A - Optical disk device - Google Patents

Abstract

PURPOSE:To stabilize an optical disk against the external vibrations or impact and to apply the stable focusing servo to the disk, by providing a vibration isolating pad to at least the upper surface side of a turntable or the clamping side of an optical disk recording medium. CONSTITUTION:A vibration isolating pad 5 is provided to the recording medium clamping side of a clamper 3 which clamps an optical disk recording medium 2 loaded to a turntable 1. Thus the medium 2 is clamped and held. The table 1 has the same diameter as a clamping area at the center part of the medium 2 so that no disturbance is given to a signal reading action out of the medium 2. While the diameter of the clamper 3 is set larger than that of the table 1. The clamper 3 presses and clamps the medium 2 via the pad 5. Thus an optical disk device is stable to the external vibrations or impact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical disc device that stably clamps and holds an optical disc recording medium and enables highly accurate focusing servo control thereof.

[Technical background of the invention and its problems]

BACKGROUND ART Recently, digital recording and reproducing of acoustic signals using PCM technology has been attracting attention due to its high fidelity. In particular, systems using so-called CDs (compact discs), which are optical disc recording media in which pits (irregularities with different reflectances) corresponding to digital data are formed on a thin metal film deposited on a transparent resin disc, have become widespread. This CD system performs signal reproduction by detecting the difference in the reflectance of the bits in a non-contact manner using, for example, an optical head using a laser as a light source. For this reason, it is important to control the focusing of the optical head on the optical disk recording medium with high precision, and for this purpose, it is necessary to stably clamp the optical disk recording medium loaded into the main body of the device. Become.

However, in the conventional clamp mechanism, as shown in FIGS. 1 and 2, for example, an optical disc recording medium 2 loaded onto a turntable 1 is moved by a clamper 3 that moves up and down opposite to the turntable 1 to produce a light beam. It is constructed so as to sandwich the disk recording medium 2 therebetween. Turntable 1
The clamper 3 holds the optical disc recording medium 2 by clamping the central part (clamping area) of the optical disc recording medium 2 from both sides, and rotates the optical disc recording medium 2. The clamper 3 is supported by an arm mechanism 4 and is moved up and down in response to the loading operation of the optical disk recording medium 2.

However, when the optical disc recording medium 2 is clamped and held in this manner, the optical disc recording medium 2 exhibits vibration frequency characteristics as shown in FIG. This characteristic is an example when the clamper section is subjected to forced displacement vibration, and generally has a large resonance point near 90H2. Moreover, the Q value of the resonance is extremely large. For this reason, if a disturbance such as a slight vibration or impact is applied to the device, the optical disk recording medium 2
vibrates greatly at a frequency near the resonance point. This vibration has a great adverse effect on the focusing servo system of the optical head. Particularly in the case of a vehicle-mounted optical disk device, the vibration frequency characteristics of the vehicle body have a large peak around 100 Hz, which is near the resonance point of the optical disk recording medium 2, as shown in FIG. Resonance is likely to occur, and it is extremely difficult to apply the focusing servo without vibration countermeasures. Conventionally, efforts have been made to support the optical disk device via a floating mechanism and thereby prevent the transmission of disturbances to the optical disk device, but this has had problems such as complicating the device configuration. .

[Purpose of the invention]

The present invention has been made in consideration of these circumstances, and its purpose is to provide a practical and stable focusing servo that is stable against external vibrations and shocks and that allows the focusing servo to be applied with high stability. The objective is to provide a high quality optical disk device.

[Summary of the invention]

The present invention is characterized in that an optical disk recording medium is held between a turntable and a clamper 9, in which a vibration-proofing pad is provided on at least one surface of the turntable surface and the optical disk recording medium clamping surface of the clamper. It is something. Furthermore, the diameter of the clamper or turntable provided with this anti-vibration pad is made larger than the diameter of the turntable or clamper that supports the clamping area on the signal reading surface side of the optical disc recording medium. The optical disk recording medium is clamped and held over a wide range on the back side of the reading surface via the vibration isolating pad.

〔Effect of the invention〕

Thus, according to the present invention, the Q value of the vibration of the optical disk recording medium clamped by the clamper mechanism can be suppressed to a very low level over the entire frequency band due to the damper action of the vibration isolating pad, and it is possible to suppress It can be used to create a strong structure. Furthermore, by making the diameter of the clamper larger than that of the turntable, or vice versa, it is possible to increase the natural vibration frequency. As a result, it is possible to shift the resonance frequency of the natural vibration mode of the optical disk recording medium from the vibration applied as a disturbance, and it is possible to prevent vibrations of the optical disk recording medium caused by the disturbance. . Therefore, together with the effect of suppressing the Q value of the resonance, it is possible to effectively suppress the vibration of the optical disk recording medium, and the focusing servo can be applied easily and with high stability. Moreover, it does not complicate the device configuration.
Great practical effects can be achieved, such as the ability to apply the present invention to existing equipment with simple improvements.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 5 to M6 show the main parts of an optical disk device according to a practical example of the present invention, and the same parts as those of the conventional device shown in FIGS. 1 and 2 are given the same reference numerals. This is an indication.

The feature of this embodiment is that a vibration isolating pad 5 is provided on the optical disc recording medium clamping surface of the clamper 3 that clamps the optical disc recording medium 2 loaded onto the turntable 1. The optical disk recording medium 2 is clamped and held via the optical disk 5. This anti-vibration pad 5 is made of, for example, elastic rubber and is attached to the entire surface of the damper 3, and presses the back side of the signal reading surface of the optical disc recording medium 2 to move the optical disc recording medium 2 onto the turntable. 1. The diameter of the turntable 1 is set to be the same as the diameter of the clamping area at the center of the optical disc recording medium 2 so as not to interfere with reading signals from the optical disc recording medium 2. Further, the diameter of the clamper 3 is set larger than the diameter of the turntable 1. In other words, the diameter of the clamper 3 is set so that the optical disc recording medium 2 can be clamped in an area wider than the clamping area on the back side of the signal reading surface of the optical disc recording medium 2, that is, in a range that covers the recorded area. It is set larger than the diameter of the innermost track of the disk recording medium 2. However, the clamper 3 equipped with such an anti-vibration pad 5 operates as shown in FIGS. 6(a) and 6(b) by the arm mechanism 4 in response to the loading of the optical disk recording medium 2 onto the turntable 1, as in the conventional device. Movement is controlled as shown in .

The optical disk recording medium 2 is rotated by a motor (not shown) while being clamped by the clamper 3 via the vibration isolating pad 5, and is subjected to non-contact signal reading by the optical head. It goes without saying that at this time, focusing servo control of the optical head on the optical disk recording medium 2 is performed.

Thus, according to the present apparatus having the structure in which the damper 3 is provided with the vibration isolating pad 5, the clamper 3 presses the optical disc recording medium 2 from the back side of the optical disc recording medium 2 via the vibration isolating pad 5 to depress the optical disc recording medium 2. 2 is clamped in the dark with the turntable 1. As a result, a damping effect is generated by the vibration isolating pad 5 on the clamping surface of the optical disc recording medium 2, and the Q value of the vibration is suppressed to a low level over almost the entire band. Therefore, even if external disturbances such as vibrations and shocks are applied to the clamped optical disc recording medium 2, the vibrations of the optical disc recording medium 2 itself can be suppressed to a small level. Moreover, in the embodiment device, the diameter of the clamper 3 is made larger than the diameter of the turntable 1 to clamp the optical disc recording medium 2 over a wide range. The natural vibration frequency can be shifted to the higher frequency side as a whole. As a result,
In the case of a vehicle-mounted device, it is possible to shift the natural vibration frequency of the vehicle body and the natural vibration frequency of the optical disk recording medium 2, and it is possible to prevent resonance of the optical disk recording medium 2 due to vehicle body vibration. becomes. Therefore, together with the reduction in the Q value of the vibration, vibrations of the optical disk recording medium 2 caused by disturbances can be effectively suppressed, and the focusing servo can be stably performed.

In addition, although the case where a vibration-proofing pad is provided on the clamper surface has been described above, a vibration-proofing pad may be provided on the surface of the turntable, and in this case, the diameter of the turntable should be made larger than the diameter of the clamper. is preferred. Further, vibration-proof pads may be provided on both the clamper and the turntable.

By the way, some optical disc recording media 2 have minute protrusions 2a formed between the recorded area and the clamping area, as shown in FIG. When clamping such an optical disc recording medium 2, if the surface of the vibration isolating pad 5 is flat, it will not be possible to stably suppress and clamp the optical disc recording medium 2 over the entire clamping surface. Therefore, in such a case, the anti-vibration pad 5
A recess 5a may be formed in a portion facing the minute protrusion 2a. By making the vibration isolating pad 5 have such a structure, it becomes possible to clamp the optical disc recording medium 2 in the recessed portion 5a while avoiding the minute protrusion 2a, thereby making it possible to stabilize the optical disk recording medium 2.

Furthermore, even when the optical disk recording medium 2 is not provided with the minute protrusions 2a, its stability and lamp operation are not hindered. Further, as shown in FIG. 8, the vibration isolating pad 5 may be structured to include a plurality of protrusions 5b of equal height, so that the optical disc recording medium 2 is spread over a wide range and clamped discretely. . That is, as shown in FIGS. 9 and 10, the vibration isolating pad 5 may be formed with minute protrusions of equal height or concentric protrusions. Even if the vibration isolating pad 5 having such a structure is adopted, the same effects as in the previous example can be achieved.

As explained above, according to the present invention, the vibration isolating pad 5 is provided on the clamper surface of the clamper 3 or the clamper surface of the turntable, so that the vibration of the optical disk recording medium 2 that is clamped is effectively suppressed. It becomes possible to suppress this. Therefore, great practical effects such as making it possible to perform focusing servo control etc. stably can be obtained. Therefore, it is possible to always stably read signals from the optical disc recording medium 2.

Note that the present invention is not limited to the above embodiments. For example, turntable 1. The diameters of the damper 3 and the vibration isolating pad 5 may be determined according to the specifications of the optical disc recording medium 2. Further, the damper characteristics of the vibration isolating pad 5 may also be determined according to the specifications. Specifically, in the case of a normal ICD (compact disc), the anti-vibration pad 5 is made of neoyaprene, 5BR (butadiene styrene copolymer), NBR (
It may be formed from a rubber material such as butadiene acrylonitrile copolymer) or sponge rubber. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing the configuration of the conventional device, Figure 3 is a diagram showing the vibration frequency characteristics of the optical disk recording medium in the conventional device, and Figure 4 is the vibration frequency of the vehicle body in which the optical disk device is mounted. FIGS. 5 and 6 are diagrams showing characteristics, and FIGS. 5 and 6 are main part configuration diagrams showing an embodiment of the present invention. FIGS. 7 to 10 are diagrams showing examples of groove bottoms of a vibration isolating pad. DESCRIPTION OF SYMBOLS 1... Turntable, 2... Optical disk recording medium, 3... Clamper, 4... Arm mechanism, 5... Anti-vibration pad. Applicant's representative Patent attorney Atsushi Suzue Takehiko Figure 6 Figure 7 Figure 10

Claims (4)

[Claims] (1) In an optical disk device equipped with a clamper that clamps an optical disk recording medium loaded on a turntable between the turntable and the turntable, the turntable surface and the optical disk recording medium clamping surface of the clamper An optical disk device characterized in that a vibration-proofing pad is provided on at least one surface of the optical disk device. (2) The optical disc device according to claim 1, wherein the clamper has a diameter larger than that of the turntable supporting the signal recording surface side of the optical disc recording medium. (3) The optical disc device according to claim 1, wherein the turntable has a diameter larger than that of the clamper that supports the signal recording surface side of the optical disc recording medium. (4) The optical disk device according to claim 1, wherein the anti-vibration pad has a plurality of protrusions having the same height, and the tip of each protrusion serves as a support surface facing the optical disk recording medium. .