JPH0485760A - Signal processing circuit for optical recording/ reproducing device - Google Patents

Abstract

PURPOSE:To improve the interchangeability by applying a prescribed input switch operations to a data processing part and a control signal processing part provided separate from each other based on the identification result of a recording format or a magneto-optical disk or a ROM disk. CONSTITUTION:A data processing part demodulates the reproduction data signal through a demodulation processing part out of those signals detected out of an optical disk by the detectors H and I and outputs the reproduction data. Meanwhile a control signal processing part 9 processes the control signals and outputs various control signals. Then the switch circuits 5a - 5e are controlled to perform the switching operations according to the type of the optical disk, to supply the reproduction data signal to a data processing part out of those detection output signals, and to supply the control signal to the part 9. In such a constitution, a signal processing circuit is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal processing circuit for an optical recording/reproducing apparatus that is compatible with a plurality of types of optical discs.

Summary of the Invention] The signal processing circuit of the optical recording and reproducing apparatus of the present invention includes a data processing section that performs signal demodulation processing on a reproduced data signal, and a control signal processing section that performs signal processing on a control signal. In addition to being provided as a separate block, the switching operation is performed according to the recording format of the optical disc to be mounted, so that among the detection output signals from the optical disc, the reproduced data signal is supplied to the data processing unit, and the control A switching means configured to supply a signal to the control signal processing unit is provided, and according to various types of optical discs,
The playback signal can be processed appropriately, and the media (
This realizes compatibility as a signal processing circuit system for optical discs).

[Prior Art] Typical optical disc recording formats that have been implemented in recent years include a continuous composite servo system (hereinafter referred to as a continuous servo system) and a sampled servo system.

The continuous servo method is a method in which continuous groups (grooves) are formed as recording tracks, and the tracking error is obtained by detecting the intensity distribution created by the interference of reflected and diffracted light from the group portion and the land portion. On the other hand, in the sampled servo method, a sampled servo bit area is formed at the beginning of each segment obtained by dividing the sector of the recording track, and a tracking servo signal is obtained from a pair of double bits in this sampled servo bit area. This is a system in which the channel clock is obtained from clock pin 1-.

Furthermore, the types of information recording formats of optical discs are as follows:
There are so-called ROM-type optical disks and optical disks, generally called magneto-optical disks (MO disks), which can be overridden as many times as they like, and each is widely practiced. The types of optical disks currently in use include at least continuous servo type MO disks, continuous servo type ROM disks, sampled servo type MO disks, and sampled servo type ROM disks. Although there will be different types of optical discs, no signal processing circuit that can handle multiple types of optical discs has been proposed, and no optical disc recording/playback device with disc compatibility has been realized, so each type must be a dedicated device. The problem is that you can't drive it.

Further, it is not preferable to simply provide a plurality of signal processing circuit systems in order to realize a device having compatibility, as this will unnecessarily increase the size and cost of the device.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and includes signal demodulation for the reproduction data signals of the reproduction data signals and control signals detected and output from the optical disc. A data processing section that performs processing and outputs playback data, and a control signal processing section that performs signal processing on control signals and outputs various control signals are provided as separate blocks. A switching operation is performed accordingly, and among the detection output signals from the optical disk,
A signal processing circuit of the optical recording and reproducing apparatus is configured to include a switching means configured to supply a reproduced data signal to the data processing section and supply a control signal to the control signal processing section.

[Function] The data processing unit and the control signal processing unit are provided as separate blocks, and the data processing unit and the control signal processing unit However, by performing a predetermined input switching operation, the recorded data and control information of the playback output from the optical disc can be distributed manually, allowing dedicated signal processing to be performed for multiple types of optical discs with different data formats. A signal processing circuit with disk compatibility can be realized without providing a circuit system.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, and in particular, a continuous servo type MO disk, a continuous servo type ROM disk, a sampled servo type MO disk, and a sampled servo type MO disk. This figure shows a signal processing circuit that is configured to be compatible with four types of optical disks, including ROM disks of the portable type.

Reference numeral 1 denotes a two-part detector (E(,I)) that detects the reflected light from the optical disk using two optical systems. Bit information obtained as a rotation angle due to the Kerr effect when the recording surface is irradiated with a laser beam is detected.

Further, when a ROM disk is being driven, the bit information thereof can be obtained by performing the calculation (H+I) in the calculation circuit 2b.

3 is a four-part detector (A, B, C, D) that detects the reflected light from the optical disk, and a focus error signal is generated by the calculation of (A, +C)-(B+D) in the calculation circuit 4a. Furthermore, in the arithmetic circuit 4b, (A
10B) is calculated, and (C1D) is calculated in the calculation circuit 4C and outputted respectively.

58 to 5e are switching circuits that perform predetermined switching operations according to the type of optical disc being driven under the control of a system controller (not shown); 6 is a switching circuit that converts the reproduced data signal supplied via the switching circuit 5a into digital data; An A/D converter 7 is a demodulation circuit system that demodulates and outputs the reproduced pig signal as bit information.

8 is an A/D converter that converts the control signal supplied via the switching circuit 5d into digital data; 9 is a control signal consisting of an address decoder, a gray code decoder, a tracking error calculation section, a position signal generator, etc. It is a processing system that generates various control information and supplies it to the system controller, servo circuit, etc.

10 is a clock regeneration circuit consisting of a PLL circuit, 11 is M
A modulation circuit unit that modulates write data when recording data on an O-type optical disk and supplies a recording signal to an optical head is shown.

The operation of this signal processing circuit will be explained for each type of optical disc being driven.

(i) In the case of continuous support type ROM disk reproduction, the connections of the switching circuits 58 to 5e are as follows.

・5a...R contacts - 5b, 5c, 5e-...C contacts 5d...Continuously switches between C, , C2 contacts to the demodulation circuit system 7 via the R contact of the switching circuit 5a. bit information of the reproduced data is supplied and demodulated. Further, the obtained bit information (binary signal) is injected into the clock regeneration circuit 10 via the C contact of the switching circuit 5e, and the clock is regenerated by PLL operation.

Further, focus error signals (A0C) (B+D) obtained by the arithmetic circuit 4a are applied to a focus servo circuit (not shown) via the switching circuits 5b and 5c.

Furthermore, the switching circuit 5d continuously switches between the C, C2 contacts, so that the signal (A+B) obtained in the arithmetic circuit 4b and the signal (C+D) obtained in the arithmetic circuit 4c are
) are alternately supplied to the control signal processing system 9 via the A/D converter 8, and a tracking error signal is generated by calculating (A+B)-(C+D) and output to a tracking servo circuit (not shown). Further, control information such as address data and position signals is detected from the calculated value of (A+B+C+D) and output to a system controller or the like.

(11) In the case of continuous servo type MO disk playback, the switching circuit 5a is connected to the M contact, and the switching circuits 5b to 5e
The connection is the same as in (i) above.

In other words, in the case of magneto-optical disks, the bit information of reproduced data is obtained as the rotation angle difference due to the Kerr effect, so
Difference signal of output of detector 1 divided into two (I-H
) is supplied to the demodulation circuit system 7 and demodulated.

On the other hand, since control signals such as address information are formed of ROM type bits, they are supplied to the control signal processing system 9 via contacts C, C2 of the switching circuit 5d, as in the case of a ROM disk.

(iii) In the case of sampled servo type ROM disk reproduction, the connections of the switching circuits 5a to 5e are as follows.

・5a...R contact ・5b...Connect to S contact when sample pulse is generated・
5c to 5e...S contact playback data demodulation processing is the same as in case (1) above, but control information such as tracking error information, address information, and gray code is obtained from the playback signal in the sample servo bit area. Therefore, the reproduced RF signal is supplied to the control signal processing system 9 via the S contact of the switching circuit 5d, and various control signals are generated. In addition, since the clock is obtained from the reproduced signal of the clock pins 1 to 1 formed in the sample servo bit area, the switching circuit 5e is connected to the S contact,
A clock bit reproduction signal is supplied to a clock reproduction circuit 10 .

Regarding the focus error signal, the difference signal obtained by the 4-division detector 3 and the arithmetic circuit 4a when the light spot scans a part of the mirror provided in the sample servo pin 1~area is considered to be the focus error signal. is obtained discretely, so the switching circuit 5b is connected at the sample timing corresponding to a part of the mirror, and the hold value of the capacitor forming the sample and hold circuit 12 is connected to the focus support circuit during the other period. is output to.

(iv) In the case of sampled servo type MO disk playback, the switching circuit 5a is connected to the M contact, and the switching circuits 5b to 5e
The connection is the same as in (iii) above.

That is, the output of the arithmetic circuit 2a that detects the data of the reflected light polarized by the Kerr effect is supplied to the demodulation circuit system 7 and demodulated, and the control information recorded in ROM type bits is It is treated as if

In the signal processing circuit of this embodiment, the switching circuit 5
By operating a to 5e, it becomes possible to perform reproduction operations corresponding to four types of optical discs.

Note that when data is recorded on an MO disk, control information is obtained by the control signal processing system 9 regardless of whether the disk is of the continuous servo type or the sampled servo type. Recording operations can be performed based on the control information.

[Effects of the Invention] As explained above, the signal processing circuit of the optical recording/reproducing apparatus of the present invention has a data processing section and a control signal processing section as separate blocks, and converts the reproduced data signal into data according to the type of optical disc. By providing switching means for supplying control signals to the processing section and supplying control signals to the control signal processing section, signals can be applied to multiple types of optical discs without the need for multiple independent signal processing systems. This has the effect that a processing circuit is realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

Claims (1)

[Claims] A data processing unit that performs signal demodulation processing on a reproduced data signal among the information detected and output from the optical disc and outputs the reproduced data; A control signal processing unit performs signal processing on the signal and outputs various control signals, and a switching operation is performed depending on the type of optical disc installed, so that the playback data is selected from among the detected output signals from the optical disc. An optical system comprising switching means configured to supply a signal to the data processing section and a control signal to the control signal processing section, and configured to be compatible with a plurality of types of optical discs. Signal processing circuit for recording/playback equipment.