JPH0453076A - Optical disk oscillation proofing structure - Google Patents

Abstract

PURPOSE:To prevent delay in the servo phase of a focus correcting operation by interposing an oscillation suppressing member, which contacts an optical disk with pressure, in a cartridge. CONSTITUTION:In a cartridge 10, sheets 11 and 12 are provided as the oscillation suppressing members. These sheets 11 and 12 are soft so as not to damage the surface of an optical disk D and formed by a material having small friction to the rotating optical disk D. The optical disk D is rotated in the cartridge 10 by the motive force of a motor and at such a time, however, the optical disk D is pressed by the upper and lower sheets 11 and 12 in the cartridge 10. Therefore, even when the disk is resonated at an about 1.4KHz resonance frequency, for example, the amplitude is suppressed. Thus, an adverse influence upon the focus servo or the like of a pickup can be prevented by the resonance of the disk.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an information medium such as an optical memory device in which an optical disk is housed in a cartridge, and in particular to an optical disk in which resonance of the disk can be suppressed within the cartridge. Regarding anti-vibration structure.

[Prior Art] As shown in FIG. 7, an optical disc D is placed on a turntable 1 provided on the spindle of a motor M, and the optical disc D is rotationally driven by the power of the motor M. The optical pickup P faces the disk D and moves in the radial direction thereof to record or reproduce information.

[Problems to be Solved by the Invention] The optical pickup P performs a focus correction operation to slightly move the objective lens 2 in the optical axis direction to align the focus of the focused light from the objective lens 2 on the recording surface of the disk D. It will be done. This correction operation is performed in a frequency band up to several kHz. However, when the vibration caused by this correction operation is transmitted through the pickup chassis and from the spindle to the optical disk D, there is a problem that the disk D is deformed as shown by the broken line in FIG. 7 and resonance occurs. For example, an optical disk D for a magneto-optical memory device has a resonance point approximately around 1.4 KHz, as shown by A in FIG. When this resonance of the optical disk D occurs, vibrations of large amplitude are transmitted from the motor M to the optical pickup P via the pickup chassis.
transmitted to. The above resonant frequency of 1.4KHz is
Since it is in the frequency band of the focus correction operation that drives the objective lens 2, when vibrations due to the resonance of the optical disk D are transmitted to the pickup P, problems such as a slow tz of the focus correction operation's phase will occur. Ru.

Conventionally, measures have been taken to address the problems caused by disk resonance as described in section 11 above. By providing a blocking structure, the disk can be
However, when this vibration isolation structure is used, it is necessary to insert an elastic body, and the vibration is prevented from being transmitted to the pickup P.
The present invention solves the conventional problems mentioned above, which affect the inclination accuracy and tilting accuracy of the disc itself, the tilting accuracy of the pull 1, etc., and suppresses the amplitude of the resonance of the disc itself and focuses at 5. Supplementary 1
The purpose of this invention is to provide an optical disc itself that can prevent problems such as servo phase delays in operation.

[Step 1 for Solving the Problems] The optical disk vibration isolation structure according to the present invention has an optical disc rotatably housed in a cartridge, and the optical disc is rotatably housed in the cartridge.
・There are 4 features: a vibration suppressing member is interposed in each of the ridges to press one optical disk into contact.

[Function] In the above-mentioned hand FC, an optical disk is housed in the car ridge, and a vibration suppressing member that presses against the optical disk is interposed in the cartridge at T2 in the disk ′:) device. The member is, for example, a soft material such as nonwoven fabric, felt, or foamed resin, and is pressed against the disk surface by a resilient member such as a leaf spring.This vibration suppressing member suppresses the amplitude that occurs when the optical disk resonates. This prevents vibrations caused by the resonance of the leading disk from being transmitted to the pickup and adversely affecting the Novoca servo.Furthermore, even if dirt or dust enters the cartridge, vibrations from soft materials such as non-woven fabric or felt can be prevented. It is possible to prevent dirt from entering the inside of the suppressing member or from landing on the disk surface.

[Example 1 Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an information medium equipped with an optical disk vibration isolation structure according to the present invention, FIG. 2 is a sectional view showing the internal structure of the information medium, and FIG. 3 is a sectional view of the information medium showing a second embodiment. It is.

The cartridge number 10 is made of resin and has a case, and an optical disc L) is rotatably inserted into the cartridge. 1 As shown in FIG. 1, a hole 10a for clamping the optical disk D is formed in the center of the cartridge 10, and a reading window 101 with a shutter, which the pickup faces, is formed in the bottom side. .

As shown in FIG. 2, sheets 11 and 12 are provided in the cartridge 10 as vibration suppressing members. The sheets 11 and 12 are made of a soft material that will not scratch the surface of the optical disc 1) and are made of a material that has low friction against the rotating optical disc D.

Specific materials include nonwoven fabric, felt, and foamed resin. Almost the entire surface of the lower sheet 1 is adhered to the inner bottom surface of the cartridge 10. The lower sheet 12 is also partially adhered to the upper surface of the cartridge 1 (,). Further, a small leaf spring 3 is glued and fixed to the inner surface of the cartridge 10, and a portion of the upper sheet 12 is pressed by the leaf spring 13. As a result, the optical disc D has sheets 11 and 121 . It is being pressed by L7. Regarding the elastic force of the leaf spring 13, it is desirable to set the elastic force as large as possible within a range where the rotational resistance of the optical disc D does not increase excessively.

When the information medium shown in FIG. 1 is loaded into an optical memory device or the like, the central part of the optical disc D is clamped from above and below through the clamping hole 10a in the center of the cartridge 10, and the optical disc D is clamped from above and below as shown in FIG. The center part of D is installed on the turntable 1. The optical disc D rotates within the cartridge 10 due to the power of the winding, but at this time, the optical disc D is held down by the upper and lower seats 1, 11 and 12 within the cartridge 10, and rotates at a resonant frequency of, for example, about 1.4 KHz. Resonance 1. However, its amplitude (the 1' amplitude indicated by A in FIG. 6) is suppressed and becomes tl.

FIGS. 4 and 5 show the effect of providing the L sheets 11 and 12. FIG. 4 shows the gain (a) and phase (b) of the focus-inverse transfer function when the information medium for the magneto-optical memory device according to the embodiment shown in FIGS. 1 and 2 is used. FIG. 5 also shows Sea I-1 in an information medium for a magneto-optical memory device.
, ], .

12 and the conventional example in which the leaf spring 13 is not provided:
! 3 (shows the gain (A) and phase (B) of the vine focus-inverse transfer function. In the conventional example shown in FIG. 5, 1.
At a frequency of 1 KHz, the amplitude of the optical f-isk D increases, causing a phase delay. However, the fourth
As shown in the figure, it can be seen that in the example of the present invention, the amplitude due to resonance of the optical disk D near 1.4 KHz is suppressed, and there is no adverse effect on the servo phase.

Also, if dirt or dust enters the inside of the cartridge 10 through the reading window 10b, this dirt or dust will be removed from the sheet]
1 and 12, dirt and dust are prevented from adhering to the surface of one disk, and a cleaning function for the disk surface can also be achieved.

Note that in the embodiments shown in FIGS. 1 and 2, 1. A sheet 12 made of, for example, a non-woven fabric is pressed against the optical disk D by a leaf spring 3. However, an elastic material such as rubber is inserted in place of the leaf spring 13, and the sheet 2 is You can also press it.

FIG. 3 shows a second embodiment of the invention.

In this embodiment, the seats provided above and below]・11a and 1
A slightly thicker disc 2a is used and inserted between the optical disc D and the inner surface of the cartridge 10 under pressure. Therefore, the optical disc D is held down by the elastic force of the compressed sheets lla and 12a, and the amplitude is suppressed.

In each of the above embodiments, as shown in FIG.
2, or lla], 2a may be in pressure contact with the optical disc D in a small area.

Effect C] As described above, according to the present invention, it is possible to suppress the amplitude when the optical disc resonates, and therefore it is possible to prevent the disc resonance from having an adverse effect on the focus servo of the pickup and the like.

Furthermore, since the vibration of the optical disc can be suppressed in the disc device itself, it is not necessary to provide a vibration prevention device on the player unit side. Furthermore, if a soft material such as nonwoven fabric or felt is used as the vibration suppressing member, it will also be possible to perform a cleaning function to prevent dirt and dust that has entered the cartridge from adhering to the disk surface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an information medium employing a vibration isolation structure according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view thereof, and FIG.
The figure is an enlarged sectional view of an information medium employing a vibration isolation structure according to another embodiment, and FIG. Fig. 5 is a line diagram showing the gain-in-no and phase of the focus-inverse transfer function according to the conventional example, Fig. 6 is a line section showing the resonance characteristics of the disk, and Fig. 7 is a side view schematically showing resonance when driving the disk. 8 10... Cartridge, 11.12... Vibration suppressing member, 13... Leaf spring, D... Optical disc. Figure 1 Figure 2 Figure 3 Figure 6'? N7 diagram

Claims (1)

[Claims] 1. An optical disc vibration isolation structure characterized in that an optical disc is rotatably housed in a cartridge, and a vibration suppressing member that presses against the optical disc is interposed in the cartridge.