JPH0828028B2 - Optical disc recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus for recording / reproducing information on / from an optical disk, and more particularly to an optical disk recording / reproducing apparatus capable of preventing dust and dirt from adhering to an optical disk. Is.

2. Description of the Related Art An optical disk recording / reproducing apparatus for recording information on an optical disk can achieve a recording density 10 times higher than that of a magnetic disk due to the high convergence of laser light and the narrow pitch of tracks. In particular, the write-once type optical disk and the magneto-optical optical disk are noteworthy in that they can record and reproduce information and can be rewritten, unlike a video disk and a compact disk for reproduction only.

FIG. 3 is a block diagram of a conventional optical disk recording / reproducing apparatus, in which 1 is a cartridge containing an optical disk, 2 is an optical disk, and 3 is a motor for rotating the optical disk 2. An optical head 4 converges the laser light on the optical disc 2 to record a signal, and reads the recorded information as a change in the reflected light of the converged laser light. Reference numeral 6 denotes a laser drive / head amplifier circuit including a laser drive unit of the optical head 4 and a head amplifier unit for detecting the focus tracking error signal 13. A focus / tracking control circuit 7 drives the actuator of the optical head 4 to focus and track the converged laser light on the guide track of the optical disk 2. Reference numeral 9 is a data modulation / demodulation circuit that digitally modulates the input data 14, demodulates the reproduced signal 15, and outputs the output data 16. Reference numeral 11 is a control MPU that controls the system of the apparatus, and 12 is a shutter provided in the opening of the cartridge 1.

In the conventional optical disc recording / reproducing apparatus configured as described above, the laser light emitted from the optical head 4 is focused on the guide track of the optical disc 2 rotating at high speed, and the focus and tracking detected by the optical head 4 are performed. The error signal 13 is input to the focus / tracking control circuit 7 to drive the actuator of the optical head 4 to perform focus control and tracking control, and irradiate the guide track with focused laser light.

The data is recorded by inputting the input data 14 into the data modulation / demodulation circuit 9
The laser light having a recordable intensity is modulated by the modulation data 17 and irradiated onto the optical disc 2.

For reproduction of data, a weak laser light of a level that is not recorded is applied to the optical disc 2, and the reproduction signal 15 that receives the reflected light of the converged laser light is demodulated by the data modulation / demodulation circuit 9 and output data 16 is output. Normally, the playback power is about 1mW,
The recording power is 5 to 10 mW.

Problems to be Solved by the Invention However, in the above configuration, the optical disc 1
Since it rotates at a high speed of about 1800 rpm, when it is continuously used for a long time, the optical disk 2 which is made of electrically insulating resin or glass as a base material is electrically charged, and dust in the air is adsorbed on its surface. The adsorbed dust absorbs laser light,
Scattering causes attenuation of tens of percent. For this reason, the recording laser power required for the recording layer of the photosensitive member vapor-deposited on the guide track is, for example, 5 to 10 mW, which is significantly insufficient at 3 to 6 mW, and signal recording cannot be performed well.

This causes a problem that the amplitude of the reproduction signal is reduced and the bit error rate is deteriorated accordingly, and further, the recording pits are not recorded up to the saturation point and the recording pits are deteriorated due to environmental changes and the life is shortened. Had a point.

Means for Solving the Problems The present invention relates to a disk control means for rotating and stopping an optical disk by driving and braking a motor, a shutter opening / closing means for opening / closing a shutter of a cartridge, and a monitoring means for monitoring a usage state of the optical disk. If the monitor means detects that the recording or reproducing operation is not performed on the optical disk within a predetermined time, the disk control means stops the rotation of the optical disk to shift to the standby state. The optical disk recording / reproducing apparatus is characterized in that

Effect of the Invention With the above-described configuration, when the optical disc is not used for a predetermined time or more, the optical disc can be prevented from being charged by rotation by stopping the rotation of the optical disc, and dust or dust can be attracted to the optical disc. Can be prevented.

Embodiment FIG. 1 shows a block diagram of an optical disk recording / reproducing apparatus in an embodiment of the present invention. In FIG. 1, the third
The same parts as those in the figure are designated by the same reference numerals. Reference numeral 5 is a shutter control circuit that opens and closes the shutter 12 of the cartridge 1, 8 is a motor control circuit that controls the rotation and stop of the motor 3, and 10 is a timing circuit that is normally built in the control MPU 11.

The operation of the optical disc recording / reproducing apparatus of the present embodiment configured as described above will be described below.

When the cartridge 1 is mounted on the optical disk recording / reproducing apparatus of this embodiment, the shutter control circuit 5 opens the shutter 12 of the cartridge 1 and clamps the optical disk 2 on the motor 3. Next, the motor control circuit 8 activates the motor 3 to rotate the optical disk 2 at a high speed of about 1800 rpm.
The focus / tracking control circuit 7 focuses the laser light of the optical head 4 on the guide track of the optical disc 2 to enable recording of data on the optical disc 2 or reproduction of data from the optical disc 2. The recording and reproducing of these data are the same as those described in detail in FIG.

FIG. 2 is a flowchart showing the operation procedure after the cartridge 1 is mounted in the optical disc recording / reproducing apparatus of this embodiment. In FIG. 2, state (a) shows a state in which recording and reproduction are possible, and state (b) shows a standby state.

In the state (a), the control MPU 11 waits for a recording or reproducing command from the host, and according to the execution command, the data modulation / demodulation circuit 9, the laser drive / head amplifier circuit 6,
The focus tracking control circuit 7 is controlled to record and reproduce data. Further, the control MPU 11 measures the waiting time of the recording / reproducing command from the host using the timing circuit 10, and when it detects that the recording or reproducing operation is not performed for a predetermined time T or more, The optical disk recording / reproducing apparatus is shifted to the state (b). That is,
The control MPU 11 stops the emission of laser light from the optical head 4, and the motor control circuit 8 stops the rotation of the motor. Further, the control MPU 11 closes the shutter 12 of the cartridge 1 by the shutter control circuit 5. After the above processing, control
The MPU 11 shifts to the standby state (b) and waits for a recording or reproducing command from the host.

In the state (b), when a recording / reproducing command is received from the host, the control MPU 11 again opens the shutter 12 of the cartridge 1, activates the motor 3, and focuses the laser light on the guide track of the optical disc 2. After that, recording and reproduction are performed.

As described above, according to the present embodiment, the predetermined T time or more,
When recording or playback is not performed, the rotation of the optical disc is stopped, and the shutter of the cartridge is closed to shift to the standby state, so that a resin such as polycarbonate or PMMA or a so-called dielectric material such as glass is used. It is possible to prevent the dust charged in the air from being adsorbed by the electric charges charged by the friction between the air and the surface of the equipment due to the rotation on the optical disk.

Further, the predetermined time T may be appropriately determined depending on the recording / reproducing operation frequency, the system throughput requirement, and the usage environment of the optical disk recording / reproducing apparatus.

Effects of the Invention As described above, according to the present invention, it is possible to prevent dust and the like in the air from adhering to the surface of the optical disk equipment, and the practical effect thereof is great.

[Brief description of drawings]

FIG. 1 is a block diagram of an optical disc recording / reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a flowchart showing an operation procedure of the optical disc recording / reproducing apparatus of the embodiment of the present invention, and FIG. 3 is a conventional optical disc recording / reproducing apparatus. It is a block diagram of. 1 ... Cartridge, 2 ... Optical disc, 3 ... Motor, 4 ... Optical head, 5 ... Shutter control circuit, 8 ...
… Motor control circuit, 10 …… Timer circuit, 11 …… Control MPU, 1
2 …… Shutter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norihisa Fukushima 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 56) References JP-A-60-171672 (JP, A) JP-A-60-177466 (JP, A) JP-A-63-14369 (JP, A)

Claims (2)

[Claims] 1. An apparatus for recording / reproducing data on / from an optical disk housed in a cartridge having an openable / closable shutter, comprising disk control means for rotating and stopping the optical disk by driving and braking a motor, and a shutter of the cartridge. A shutter opening / closing means for opening / closing the optical disk, and a monitor means for monitoring the usage state of the optical disk, and it is detected by the monitoring means that the recording or reproducing operation is not performed on the optical disk within a predetermined time. In this case, the optical disc recording / reproducing apparatus is characterized in that the rotation of the optical disc is stopped by the disc control unit and the shutter of the cartridge is closed by the shutter opening / closing unit to shift to a standby state. 2. The optical disk recording / reproducing apparatus according to claim 1, wherein the monitor means is composed of a clock circuit.