JPH04176022A - Optical disk driver - Google Patents

Abstract

PURPOSE:To prevent dust from adhering to an optical disk by a method wherein a capacitance sensor is provided to detect a capacitance between the sensor and an optical disk and the a charged level of the optical disk is detected based on the detection results of the capacitance sensor. CONSTITUTION:A capacitance sensor 8 is provided on the side of a motor 4 from a moving head 31 on a carriage 34. The capacitance sensor 8 is provided with an electrode 80 facing the surface of the optical disk 92 and detects a charged level of the optical disk 92 by checking the capacitance between the electrode 80 and the optical disk 92. Thus, the charged condition of the optical disk 92 can be known which is a factor of adhesion of dust to the optical disk 92, to enable the removal of the charging before adhesion of the dust to the optical disk 92 increases thereby preventing dust from adhering to the optical disk.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disc drive device for rotationally driving an optical disc.

[Conventional technology]

2. Description of the Related Art Some optical disk drive apparatuses record and reproduce information by rotationally driving an optical disk, which is an information storage medium, which houses an optical disk therein and performs the recording and reproduction by driving the optical disk.

Since the optical disk uses polycarbonate, which is relatively easily charged, as its substrate material, the optical disk is charged by the air friction generated by the rotation of the optical disk, and dust is attracted and attached to the optical disk by this charging. When the amount of adhering dust increases, abnormalities such as data recording errors and reproduction errors occur, and the reliability of the device decreases. For this reason, it is necessary to suppress the adhesion of dust to the optical disk, and an optical disk drive device equipped with means for removing the dust has been proposed (Japanese Patent Laid-Open No. 63-2
No. 44461, JP-A-63-244467.

(Japanese Unexamined Patent Publication No. 63-244470).

[Problem to be solved by the invention]

However, the optical disc drive device equipped with a means for removing dust adhering to optical discs as described above has not been able to eliminate the cause of dust adhesion, and has not been able to fundamentally solve the problem of dust adhesion to optical discs. That was the reality.

The present invention has been made in view of the above circumstances, and by detecting the amount of charge on the optical disk, which is a cause of dust adhesion to the optical disk, it is possible to prevent dust from adhering to the optical disk. The purpose is to provide disk devices.

[Means for Solving the Problems] An optical disc drive device according to the present invention includes a capacitance sensor that detects the capacitance between the optical disc and the optical disc, and determines the charging of the optical disc based on the detection result of the capacitance sensor. It is designed to detect the amount.

[Effect]

When the amount of charge on an optical disc is large, dust tends to adhere to the optical disc. The relationship between the amount of charge on the optical disk and the capacitance between the capacitance sensor and the optical disk is that as the amount of charge increases, the capacitance tends to increase accordingly, and the amount of charge on the optical disk becomes extremely large. When it becomes large, discharge occurs between the capacitance sensor and the optical disk. Since there is such a relationship between the amount of charge and the capacitance, it is possible to know when the amount of charge on the optical disk is large by determining whether the detection result of the capacitance is greater than or equal to a predetermined amount. In particular, when a discharge as described above occurs, the output signal level of the capacitance sensor increases rapidly.
If you capture this dramatic increase in the output signal level,
A state in which the amount of charge is extremely large and red can be identified.

[Examples] The present invention will be specifically described below based on drawings showing examples thereof. FIG. 1 is a schematic perspective view of an optical disc drive device according to the present invention.

1 in the figure is a box-shaped case of an optical disk drive,
A long hole-shaped disk insertion opening 10 is formed on the side surface of the case 1, through which a flat box-shaped optical disk cartridge 9 is inserted and removed.

The optical disc cartridge 9 rotatably accommodates a disc-shaped optical disc 92 inside a thin handbox-shaped cartridge 91.
provided on each of both sides of the cartridge 91 parallel to 2,
An opening of a predetermined width that exposes the optical disc 92 over approximately 1/2 of its radial length, and openings on both sides simultaneously by sliding on the surface of the cartridge 91 in a direction parallel to the optical disc 92. A shutter 910 that opens and closes is provided. Further, a metal bubble 920 is attached to the center of the optical disc 92. When such an optical disc cartridge 9 is stored, the shutter 910
When the shank 910 is closed and stored in an optical disk drive, a predetermined opening mechanism (not shown) opens the shank 910.
is about to be opened.

FIG. 2 is a schematic side sectional view of an optical disk drive according to the present invention, and FIG. 3 is a schematic plan view of the inside thereof.

A plate-shaped base 21 supported by supporting members 22, 22, etc. is disposed at the bottom of the case 1, and a motor 4 for rotationally driving an optical disc 92 is installed in the center of the base 21. installed. A turntable 5, which is attached to the rotating shaft of the motor 4 and on which an optical disk 92 is placed and rotated, is disposed above the motor 4. Further, around the motor 4 on the base 21, there are rod-shaped support members 23, 23, . . . that support the optical disc cartridge 9.
・is erected.

When the optical disc cartridge 9 is inserted into the case 1, the support member 23.2 is loaded by a predetermined loading mechanism.
3..., and the optical disk 92 is fixed on the turntable 5 by the hub 920 being attracted by a magnet (not shown) in the turntable 5.

Further, a separate optical head 3 is provided on the base 21 near the side opposite to the side where the disk insertion slot 10 is provided. The optical head 3 generates a laser beam with a predetermined diameter, projects it in the radial direction of an optical disk 92 placed on the turntable 5, receives reflected light from the optical disk 92, and detects the amount of light. Fixed herad 31
and a yoke 33.3 of a linear motor attached to the base of the fixed throat 31 and extending in the radial direction of the optical disk 92.
3, and a moving head 31 around which a voice coil (not shown) is wound or provided on a carriage 34 of a near motor. The moving head 31 includes a reflecting mirror (not shown) that reflects the projected laser beam toward the optical disk 92.
and an objective lens 320 that focuses the laser beam on the two surfaces of the optical disk, and is moved along the yokes 33 and 33 by the movement of the carriage .

Furthermore, a capacitance sensor 8 is provided on the carriage 34 closer to the motor 4 than the moving head 12 in order to detect the amount of charge on the optical disc 92. There is.

This capacitance sensor 8 includes an electrode 80 facing the disk surface of an optical disk 92, and this electrode 80 and the optical disk 9
2, and by detecting the capacitance, the amount of charge on the optical disk 92 is detected. That is, as the amount of charge on the optical disk 92 increases, the capacitance tends to increase accordingly, and in particular,
When the amount of charge becomes extremely large, a discharge state occurs between the optical disk 92 and the electrode 80. When such a discharge state occurs, the level of the output signal of the capacitance sensor 8 increases rapidly due to the discharge, and by detecting this, it is possible to determine whether the optical disc 92 is extremely charged.

As shown in FIG. 3, it has a laser diode as a light source, a collimator lens and a slit for converting the irradiation light of the laser diode into a spot light, and the spot light is arranged at a predetermined angle with respect to the vertical direction with respect to the optical disk 92. A light emitting unit 6a that emits light, a condenser lens that condenses the spot light reflected by the optical disk 92, and a two-dimensional semiconductor device detection element that receives the condensed light.
n Sensing Device (hereinafter referred to as PSD), and a light receiving unit 6b that detects the position of the optical axis of the reflected spot light on the light receiving surface on the PSD and the light amount thereof is connected to the base 21 via the yoke 33.33. are placed facing each other. The light emitting section 6a and the light receiving section 6b are operated by a tilt angle detection circuit (not shown) using the position detection function of the PSD.
This is a tilt detector that detects the tilt of the surface of the optical disc 92 in the circumferential direction and the radial direction. In addition, the light emitting section 6a and the light receiving section 6b can also detect the amount of dust attached to the optical disk 92 based on the amount of light received by the light receiving section 6b, as described later.

Further, in the vicinity of the light emitting section 6a, a static elimination blower, which has a built-in air blower and an electrode for generating ions, removes the charge on the optical disk 92 by emitting ion wind from the small diameter radiation lower 0. The optical disc cartridge 9 is disposed with the lower 0 facing the opening of the optical disc cartridge 9.

Next, the configuration of a control circuit for suppressing charging of the optical disk drive device will be described. FIG. 4 is a schematic block diagram showing the configuration of a control circuit for suppressing charging of an optical disk drive device.

In the figure, 100 is a CPU that performs overall control regarding the driving of the optical disk drive device, and the input side port of the CPU 100 is connected to the capacitance sensor 8 and the light receiving section 6b of the tilt detector. On the other hand, other devices 102 such as a static elimination blower drive circuit 101 for driving the power supply blower 7 and a drive circuit for the motor 4 are connected to the output side boat of cpuloo.

Next, a control procedure for charge suppression control in the optical disc drive device configured as described above will be explained. FIG. 5 is a flowchart showing a control procedure for charging suppression control.

First, the output level of the detection signal of the capacitance sensor 8 is read into the CPU 100 (step 1).

Next, it is determined whether the read output level is equal to or higher than a predetermined value (step 2).

If it is determined that the output level read in step 2 is equal to or higher than the predetermined value, the amount of charge on the optical disk 92 is extremely large, so discharge occurs and the output signal level of the capacitance sensor becomes high. be. In such a case, dust is likely to adhere to the optical disk 92 due to its electrical charge, so please drive the static elimination blower 7 (step 3).
Then, return to step 1 and repeat the process as described above. When the static elimination blower 7 is driven, ion wind is blown onto the optical disc 92, and the electrical charge on the optical disc 92 is removed.

On the other hand, if it is determined in step 2 that the read output signal level is less than the predetermined value, the amount of charge is low, so recording and reproduction by the optical head 3 is started (step 4), and processing is started. Terminate it.

Further, by setting a predetermined threshold value for the amount of light received by the light receiving portion 6b of the tilt detector, and determining whether or not the amount of light received by the light receiving portion 6b is below the threshold value, the amount of dust attached to the optical disc 92 can be determined. can be detected. This is because when the amount of dust attached to the optical disc 92 increases, the light emitted from the light emitting part 6a is scattered by the dust attached to the optical disc 92, and the amount of light received by the light receiving part 6b decreases, so the amount of light received by the light receiving part 6b decreases. This is because if the value is below the dark value, it can be determined that there is a large amount of dust attached.

In this embodiment, the static eliminating blower 7 is built into the optical disk drive device, but the present invention is not limited to this.
may be provided outside the case 1.

〔Effect of the invention〕

As detailed above, the optical disc drive device according to the present invention includes:
Since a capacitance sensor is installed and the capacitance sensor detects the amount of charge on the optical disk, it is possible to know the state of charge on the optical disk, which is the cause of dust adhesion to the optical disk. The present invention has excellent effects, such as being able to remove the charge before the amount of adhesion increases, and making it possible to prevent dust from adhering to the optical disk.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an optical disk drive device according to the present invention, FIG. 2 is a schematic side sectional view thereof, FIG. 3 is a schematic plan view of the inside thereof, and FIG. 4 is charge suppression of the optical disk drive device. FIG. 5 is a schematic block diagram showing the configuration of a control circuit for use in the present invention, and FIG. 5 is a flowchart showing a control procedure for charge suppression control. 8... Capacitance sensor 92... Optical disc,
In the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa O0

Claims (1)

[Claims] (1) An optical disc drive device for rotationally driving an optical disc, comprising: a capacitance sensor that detects capacitance between the optical disc and the optical disc.