JPH03205625A - Optical system recording and reproducing device - Google Patents

Abstract

PURPOSE:To stably perform the binarization of a regenerative signal of pits on an optical disk by providing a laser power diagnostic means and detecting deterioration of a semiconductor laser in recording power. CONSTITUTION:In case of abnormality in a laser control circuit 6, this abnormality is detected by the laser power diagnostic means J. Then, immediately after booting a recording medium 1, a head 3 is moved to a specific position of the medium, for example, if an optical disk is used as the recording medium, to its innermost circumference, where a deterioration of laser power is detected in this position by the laser power diagnosing means J. Consequently, by informing the information of the deterioration of laser power to a control system after the detection, the necessity of changing a laser for the head 3 can be confirmed. By this method, whether the laser power of the optical head is deteriorated or not can always be acknowledged prior to recording to the optical disk, so that the binalization of the regenerative signal of pits on the optical disk is stably performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an optical recording system having a function of self-diagnosing the recording power of a laser used for optical recording and reproduction using an optical disk, card, etc. as a recording medium. The present invention relates to a playback device.

[Conventional technology]

In recent years, this type of optical recording and reproducing device is used for video discs,
There are promising products that have entered the industrial world for use in CDs, office file memories, and personal computers.

An example of a conventional optical recording/reproducing device will be described below with reference to the drawings.

FIG. 2 shows the basic configuration of a conventional optical recording and reproducing apparatus. In this figure, (l) is an optical disk as a recording medium, and (2) is a disk motor for rotating the optical disk (1). (3> is an optical disk (1
) is an optical head for recording signals on the optical disk (1) and reproducing the signals recorded on the same optical disk (1), which includes a semiconductor laser, an optical system, an objective lens, a driving actuator, a focus error detection system, and a tracking detection system. The light beam emitted from the semiconductor laser is focused by an objective lens and reaches the recording film of the optical disk, and the light beam reflected here is sent to a photodetector for error detection. This photodetector detects deviations in the focus direction and tracking direction, and drives the objective lens by an actuator in order to correct the deviations in each direction to within predetermined values.

(4) is a linear actuator, which is an optical head (3
), a coil, a magnet, a yoke, and a carriage rail.
The optical head (3) is moved to a target position in the radial direction. (
5) is an amplifier circuit that amplifies the output signal from the signal detection circuit of the optical head (3), (6) is a semiconductor laser drive circuit as a laser control circuit, and (7) is a photodetector for detecting focus errors and tracking errors. (8) is a disk motor drive control circuit.

(9) is a signal processing circuit which sends the pit playback signal from the optical head (3) amplified by the amplifier circuit (5) of the signal detection circuit as binary data to the drive control circuit. During recording, the output of the laser beam is irradiated onto the disk surface of the optical disk (1) in the recording power mode in accordance with a signal from the drive control circuit (13), which will be described later, thereby forming a row of pits on the recording film. Furthermore, during reproduction, by setting the output of the laser light to the reproduction power mode, the presence or absence of pits can be read by the intensity of the amount of reflected light.

(IO) is the drive circuit for the linear actuator (4),
Control is performed to move the optical head (3) at high speed to a target position based on the position signal and speed signal detected by the photodetector of the optical head (3). (+1) is the focus control circuit, (
12) is a tracking control circuit.

The drive control circuit (13) receives commands from the controllers such as the respective control circuits, executes and controls various operations, and sends the execution state to each controller.

The operation of the optical recording/reproducing apparatus configured as shown above will be explained below.

First, a disk (!) is mounted on the disk motor (2). The disk motor drive control circuit (8) controls the disk motor (2) according to the command from the drive control circuit (13).
Controls the rotation speed to a constant value. Next, drive control circuit (
13), the semiconductor laser of the optical head (3) is controlled by the semiconductor laser drive circuit (B).

Historically, the focus direction and tracking direction are controlled by a focus control circuit (11) and a tracking control circuit (l2).
). At this time, the optical head (3) is moved by a drive circuit (10) using a linear actuator (4). After focus and tracking control operations are performed by the focus control circuit (II) and the tracking control circuit (12), the signal detected is amplified by the amplifier circuit (5) of the signal detection circuit and sent to the signal processing circuit (9). , This signal processing circuit (9) binarizes the signal and outputs it to the drive control circuit (l3).
It is to be sent to.

[Problem to be solved by the invention]

However, according to the conventional configuration as shown in L, fluctuations in the power emitted from the semiconductor laser are controlled by the semiconductor laser drive circuit (6) according to commands from the drive control circuit (13).
However, it is impossible to clearly detect the power deterioration of the semiconductor laser using these circuits. For this reason, if the power of the semiconductor laser is degraded, there is a problem in that data errors occur when the reproduced signal of the bits is binarized during recording on the optical disc 0).

The present invention was made in view of the above-mentioned problems, and always detects the deterioration of the recording power of a semiconductor laser prior to recording information on an optical disc, thereby improving the reproduction signal of the pits on the optical disc. The object of the present invention is to provide an optical recording and reproducing device that can stably perform value conversion.

[Means to solve the problem]

In order to achieve the above object, the optical recording and reproducing apparatus of the present invention includes a head that records signals on a recording medium using a laser and reproduces the signals recorded on the recording medium, and a head that controls the laser power of the head. a laser control circuit;
It has a diagnostic function to detect an abnormality in this laser control circuit, and detects whether or not there is an abnormality in the laser power at a specific position on the recording medium immediately after the recording medium is started to rotate or run in a state where recording and reproduction is possible. The invention is characterized in that it has a laser power diagnostic means for diagnosing.

[For production]

With the above configuration, the present invention can first detect an abnormality by the laser power diagnostic means when there is an abnormality in the laser control circuit.

In addition, immediately after starting a recording medium, a specific position on the same medium,
For example, if an optical disk is used as the recording medium, the head can be moved to the innermost circumference of the disk, and at that position, the laser power diagnostic means can detect the deterioration of the laser power. By providing information on deterioration, it is possible to confirm the necessity of replacing the laser head.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an optical recording/reproducing apparatus according to this embodiment. In this figure, the same reference numerals are given to parts that are common in structure and operation to those of the prior art example described above, and their explanations are omitted to avoid duplication.

(J) is a laser power diagnostic means, which has a diagnostic function to detect an abnormality in the semiconductor laser drive circuit (6) as a laser control circuit, and also rotates the optical disk (1) to a state where recording and reproduction are possible. Immediately after the optical disk (1) is started, it is used to diagnose whether there is an abnormality in the laser power at a specific position on the optical disk (1). a comparator (I4) for comparing the output with ref, and a changeover switch (I5) for switching the output of the amplifier (5) between a path to the signal processing circuit (9) and a path to the comparator (I4).
).

The operation of the optical recording/reproducing apparatus equipped with the laser power diagnostic means (J) as described above will be described below.

First, after the optical disk (1) is mounted on the disk motor (2), the disk motor drive control circuit (8) controls the number of revolutions of the disk motor (2) to be constant according to a command from the drive control circuit (13). Next, drive control circuit (13
) to light by command. The semiconductor laser (3) is controlled to play by a semiconductor laser drive circuit (6). Further, the focus direction and tracking direction are controlled by a focus control circuit (l1) and a tracking control circuit (l2). At this time, the optical head (3) is fed by a drive circuit (IO) using a linear actuator (4).
). After focus and tracking control operations are performed by the focus control circuit (11) and the tracking control circuit (l2), the signal detection is amplified by the amplifier circuit (5), and then sent to the signal processing circuit (15) via the switching switch (l5). 9), binarizes the signal and sends it to the drive control circuit (1
Send to 3).

The optical recording and reproducing device is now in the reproducing state.

Thereafter, the linear actuator (4) is operated to the innermost circumference by the drive control circuit (l3). Next, the laser power is deflected to recording power by the drive control circuit (l3), and the comparator (l4) is deflected by the switching switch (l5).
The return destination from the optical disc (1) is detected by the amplifier circuit (5), and the detected signal is compared by the comparator (4). If the signal is higher than the reference setting voltage Vref, the laser power is Diagnosed as normal, drive control circuit (I)
3), and change the selector switch (l5) to the path of the signal processing circuit (9) to enable normal operation.

Furthermore, when the detection signal is lower than the reference setting voltage V ref, it is diagnosed that the laser power has deteriorated, an abnormal signal is sent to the drive control circuit (I3), and the changeover switch (L
5) is changed to the path of the signal processing circuit (9), the operation of the optical recording/reproducing device is stopped, and the laser is changed.

As described above, according to this embodiment, immediately after entering the playback state, the linear actuator (4) moves the optical head (3) to the innermost circumference of the optical disk (1), and the recording power is forcibly emitted. The returned light is turned into light, received by Sodo's detector,
The comparator (
14), so the optical head (3)
Deterioration of laser power can be detected. If the laser power deteriorates, the laser power diagnosis means (J) is operated every time the optical disk (1) is loaded, so that the laser power deterioration can always be recognized.

Note that although the present invention has been described with reference to disks, it is also effective for media such as tapes and cards.

〔Effect of the invention〕

As explained above, the present invention has a diagnostic function for detecting an abnormality in the laser control circuit, and immediately after the recording medium is started to rotate or run in a state in which recording and reproduction are possible, the recording medium is activated. At a specific location,
By providing a laser power diagnostic means for diagnosing the presence or absence of an abnormality in the laser power, it is possible to always recognize whether or not the laser power of the optical head has deteriorated before recording on the optical disc, making it possible to reproduce pits on the optical disc. It has achieved the excellent effect of stably converting signals into binary signals.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an optical recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing the basic configuration of a conventional optical recording/reproducing apparatus. (1) Recording medium, (3) Head, (6)
... Laser control circuit, (J) ... Laser power diagnostic means.

Claims (1)

[Claims] A head that records signals on a recording medium using a laser and reproduces the signals recorded on the recording medium, a laser control circuit that controls the laser power of the head, and a diagnostic function that detects abnormalities in this laser control circuit. and laser power diagnostic means for diagnosing the presence or absence of an abnormality in laser power at a specific position of the recording medium immediately after the recording medium is started to rotate or run in a state in which recording and reproduction are possible. An optical recording and reproducing device characterized by: