JPH01144227A - Information recorder - Google Patents

Abstract

PURPOSE:To prevent information already recorded on a recording medium fro being destroyed at the time of performing an initial operation by generating a laser beam at a position where a light emitting means corresponds to the information non-recording part of the recording medium, measuring the light emitting output of the laser beam, and stopping light emitting output when the abnormal light emission of the laser beam is detected. CONSTITUTION:The title recorder is constituted in such a way that the light emitting means 6 is moved to the position where the laser beam is projected on information non-recording areas (b) and (c) by a moving means 5 if it is not conformed to the position where the laser beam is projected on the information non-recording areas (b) and (c) at the time of performing the initial operation by an information recorder and after that, the laser beam is emitted, and also, the light emitting output of the laser beam is measured, and when the abnormal light emission of the laser beam is detected, the light emitting output is stopped. In such a way, it is possible to prevent the information recorded on the recording medium 1 from being destroyed even when a state where the abnormal light emission of the laser beam is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an information recording device such as an optical disk device that records information on, for example, an optical disk.

(Prior Art) Conventionally, in information recording devices such as optical disk devices that use optical means to record information on a recording medium such as a write-once or erasable optical disk, a laser beam used as a recording means is used. Before emitting light from the (radiation source), make sure that the cover to avoid harmful effects on the human body is properly closed and no laser light leaks outside the device, and that the optical disc is installed in the specified position. It checks various conditions such as whether the optical disk is rotating or whether the optical disk is rotating, and only when all these conditions are satisfied does initial operations such as emitting laser light and pulling in the focus servo start. There is.

However, in such conventional optical disk devices,
When emitting laser light in the initial operation, no particular consideration is given to the position of the optical head relative to the surface position of the optical disc. In other words, on the premise that the laser light emission output always has a specified value, the laser light is emitted regardless of whether the optical head corresponds to the information recording area or the non-information recording area of the optical disc. It emits light.

However, in write-once or erasable optical disk devices, information on the optical disk is read with a relatively low light emitting output, while information is recorded on the optical disk with a relatively large light emitting output above a certain value. It looks like this. Therefore, if the light output exceeds a certain value, undefined information will be written to the optical disc even if it was not intended for recording, and as a result, the information that has already been recorded will be destroyed. .

In this way, if the optical head corresponds to the information recording area of the optical disk and the laser drive circuit malfunctions and emits abnormal light, the information recorded in that information recording area will be destroyed. There is a problem in that if such abnormal light emission is left untreated, the information recorded on the optical disc will be more likely to be destroyed.

(Problems to be Solved by the Invention) The present invention provides that when emitting a laser beam in the initial operation as described above, if the light emitting means corresponds to the information recording area of a recording medium such as an optical disk, the information recording area is emitted there. This was done to solve the problem that there is a risk of destroying the recorded information, and if left unattended, the destruction will spread. The purpose of the present invention is to provide an information recording device that does not destroy the information that is stored.

[Structure of the Invention] (Means for Solving the Problems) The information recording device of the present invention includes a light emitting means for emitting a laser beam to a recording medium having an information recording area and an information non-recording area, information recording means for recording information on the recording medium by controlling light emission of the means; moving means for moving the light emitting means in a radial direction of the recording medium; and the light emitting means moved by the moving means. a first detection means for detecting that the irradiation position of the laser beam by the means corresponds to an information-free area of the recording medium; and when the first detection means does not detect the correspondence;
a first processing means for moving the light emitting means by the moving means; and a second processing means for causing the light emitting means to emit a laser beam when the correspondence is detected by the first detection means.
and a second processing means for detecting whether or not the light emission output of the laser light from the light emitting means is abnormal when the laser light is emitted by the light emitting means according to the processing of the second processing means. The present invention is characterized in that it is equipped with the following detection means.

(Function) When the information recording device performs an initial operation, if the light emitting means does not correspond to the position where the laser beam is irradiated to the information-free area of the recording medium, the information-free area is moved by the moving means. The device moves the laser beam until it corresponds to the irradiation position, then emits a laser beam, measures the output of the laser beam, and, if abnormal emission is detected, stops the output of the laser beam, for example. . As a result, even if a situation such as abnormal emission of laser light occurs, the information recorded on the recording medium will not be destroyed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of an information recording device, such as an optical disk device, according to the present invention. In other words, an optical disc (
The recording medium 1 is formed by coating a metal film layer of tellurium, bismuth, or the like in a donut shape on the surface of a circular substrate made of, for example, glass or plastic.

The optical disc 1 has an information recording area a where information is recorded.
and an information non-recording area (a) and (c) in which no information is recorded, which are provided at the inner and outer circumferential portions.

The optical disc 1 is rotationally driven by a spindle motor 2.

The spindle motor 2 outputs a rotational speed signal S1 indicating its rotational speed to a phase comparator 3 forming a PLL (phase locked loop) circuit. This phase comparator 3 has
A reference signal S2 having a predetermined frequency is supplied from a frequency generating means (not shown).

The phase comparator 3 compares the phases of the rotational speed signal S1 supplied from the spindle motor 2 and the reference signal S2 supplied from the frequency generating means, and outputs the comparison result to the motor driver 4. be. That is, when the rotation speed (frequency) of the spindle motor 2 is less than the frequency of the reference signal S2, a signal is output to further increase the rotation speed, and the rotation speed (frequency) of the spindle motor 2 is lower than the frequency of the reference signal S2. If it is large, a signal is output to reduce the rotation speed.

Furthermore, when the phase comparator 3 detects that the frequencies (phases) of the rotational speed signal S1 and the reference signal S2 match, it outputs a matching signal S3 indicating this to the control circuit 9. ing.

The motor driver 4 rotates the spindle motor 2 in response to a signal supplied from the phase comparator 3.

An optical head (light emitting means) 6 is disposed below the optical disc 1 . This optical head 6 is used for recording or reproducing, and is constructed as follows.

That is, as shown in FIG. 3, 7 is a semiconductor laser oscillator, which is controlled by a laser drive circuit 10. As shown in FIG. This semiconductor laser oscillator 7 emits diverging laser light. In this case, when writing (recording) information on the recording film of the optical disc 1, a laser beam whose light intensity is modulated according to the information to be written is generated, and the information is read from the recording film of the optical disc 1. (Reproduction) A laser beam having a constant light intensity is generated at z.

The diverging laser beam generated by the semiconductor laser oscillator 7 is converted into a parallel beam by the collimator lens 60 and guided to the polarizing beam splitter 61. The laser beam guided to the polarizing beam splitter 61 passes through the polarizing beam splitter 61, enters the objective lens 62, and is focused by the objective lens 62 toward the recording film of the optical disc 1.

Here, the objective lens 62 is supported movably in the front axis direction and in the direction orthogonal to the optical axis, and when the objective lens 62 is positioned at a predetermined position, the focused light emitted from the objective lens 62 is The beam waist of the laser beam is projected onto the surface of the recording film of the optical disc 1, and the minimum beam spot is formed on the surface of the recording film of the first disc 1.

In this state, the objective lens 62 is kept in focus and on track, allowing information to be written and read.

Further, the diverging laser beam reflected from the recording film of the previous disk 1 is converted into a parallel beam by the objective lens 62 when focused, and is returned to the polarizing beam splitter 61 again. This light is reflected by the polarizing beam splitter 61 and irradiated onto the photodetector 64 by the projection lens 63.

This photodetector 64 is constituted by a photodetection cell that converts the light imaged by the projection lens 63 into an electrical signal.

A photoelectric conversion element (second detection means) 11 is provided on the opposite side of the recording or reproducing laser beam emission port of the semiconductor laser oscillator 7. The photoelectric conversion element 11 is irradiated with monitor light from the upper semiconductor laser oscillator 7, converts the monitor light into an electrical signal, and outputs the electrical signal to the laser drive circuit 10.

The moving mechanism 5 for moving the optical head 6 is constituted by, for example, a linear motor. That is,
The linear motor is composed of a drive coil as a movable part and a permanent magnet as a fixed part. By exciting the drive coil, the movable part on which the optical head 6 is mounted moves in the radial direction of the optical disc 1 (in the direction of arrows A and B in the figure). ).

Further, the position detector (first detection means) 8 is constituted by, for example, a photo ink labeler, etc., and the optical head 6 is at the initial position, that is, the position where the laser beam is irradiated by the optical head 6 is the position where no information is recorded on the optical disc 1. It is provided at a position to detect that it corresponds to the area. A position detection signal S4 from the position detector 8 is output to a control circuit 9.

That is, as shown in FIG. The position detection signal S4 is output by blocking the photo ink club with the detected body 6a.

The control circuit (control means) 9 is composed of, for example, a microprocessor, and controls the entire apparatus. The control circuit 9 determines that the optical disc 1 is rotating at a constant rotation based on the coincidence signal S3 from the phase comparator 3, and receives the position detection signal S from the position detector 8.
4, it is determined that the optical heald 6 corresponds to the initial position. The control circuit 9 controls the laser drive circuit 10 when the coincidence signal S3 from the phase comparator 3 and the position detection signal S4 from the position detector 8 are supplied during the initial operation upon power-on. A laser beam is emitted from a semiconductor laser oscillator 7. Furthermore, if the position detection signal S4 is not supplied from the position detector 8 at the time of the initial operation, the control circuit 9 controls the moving mechanism 5 until the position detection signal S4 is supplied from the position detector 8. Then, the optical head 6 is moved in the direction of arrow A in the figure.

The laser drive circuit 10 is configured as follows. That is, the amplifier 12 outputs a monitor signal S6 obtained by amplifying the output signal of the photoelectric conversion element 1 to the error amplifier 13 and the voltage comparator 14.

The error amplifier 13 is supplied with a reference voltage S, 7 from a constant voltage source (not shown).

The error amplifier 13 receives a monitor signal S6 supplied from the amplifier 12 and a reference voltage S7 supplied from the constant voltage source.
The comparison result is output to the driver 15.

The driver 15 drives the semiconductor laser oscillator 7 in accordance with the signal supplied from the error amplifier 13. Note that power is supplied to the driver 15 from a power supply device 18 via a switch 17.

On the other hand, the voltage comparator (second detection means) 14 is supplied with a comparison voltage s8 from a constant voltage source (not shown).

This comparison voltage S8 is a voltage at the boundary where, if a voltage higher than this is applied to the semiconductor laser oscillator 7, the information recorded thereon will be destroyed when the laser light is irradiated onto the optical disc 1. .

The voltage comparator 14 compares the monitor signal S6 supplied from the amplifier 12 with the comparison voltage S8 supplied from the constant voltage source, and outputs the comparison result to the control circuit 9 and the AND gate 16. It is something.

The AND gate 16 receives a control signal S from the control circuit 9.
5, and its output is supplied to switch 17.

The switch 17 is configured to cut off or turn on the power supplied from the power supply device 18 to the driver 15 in accordance with a signal from the AND gate 16.

Next, the operation in such a configuration will be explained.

For example, if a power switch (not shown) is turned on,
First, the control circuit 9 rotates the spindle motor 2, that is, the optical disc 1, by controlling the motor driver 4.

The control circuit 9 also receives a position detection signal S from the position detector 8.
4 is being supplied, and the position detection signal S4 is detected.
is supplied, it is determined that the initial position of the optical head 6, that is, the position where the laser beam is irradiated by the optical head 6 corresponds to the non-information recording area of the optical disc 1.

As a result of the above check, the position detection signal S from the position detector 8 is
4 is not supplied, the control circuit 9 drives the moving mechanism 5 to move the optical head 6 in the direction of arrow A in the figure.

Then, when the position detection signal S4 is supplied from the position detector 8, the control circuit 9 stops the movement of the optical head 6 by the movement mechanism 5.

When the control circuit 9 has determined that the optical head 6 corresponds to the initial position and the coincidence signal S3 is being supplied from the phase comparator 3, the control circuit 9 uses the laser drive circuit 10 to The semiconductor laser oscillator 7 is driven to generate laser light.

As a result, the optical disc 1 is irradiated with laser light.

Next, when the semiconductor laser oscillator 7 is driven to emit laser light, the photoelectric conversion element 11 is irradiated with the monitor light. Thereby, the photoelectric conversion element 11 converts the monitor light into an electrical signal and supplies it to the amplifier 12. Then, the amplifier 12 amplifies this to a predetermined level and supplies it to the error amplifier 13 and voltage comparator 14.

Thereby, the error amplifier 13 compares the monitor signal S6 and the reference voltage S7, amplifies the difference between them, and supplies the amplified difference to the driver 15. That is, the error amplifier] 3 adjusts its output voltage so that if the voltage of the monitor signal S6 is lower than the reference voltage S7, the light emission output is increased, and if the voltage of the monitor signal S6 is higher than the reference voltage S7, the light emission output is decreased. Adjust and output.

As a result, the driver 15 converts the received signal into power sufficient to drive the semiconductor laser oscillator 7 and supplies the power to the semiconductor laser oscillator 7. Thereby, the semiconductor laser oscillator 7 outputs the amount of laser light according to the voltage.

Through this operation, the voltage of the monitor signal 6 acts to have the same potential as the reference voltage S7, thereby applying a constant voltage to the semiconductor laser oscillator 7 and keeping its light emission output constant. .

On the other hand, the monitor signal S6 is also supplied to the voltage amplifier 14. Thereby, the voltage amplifier 14 compares the voltage of the monitor signal S6 and the voltage of the comparison voltage S8, and outputs an alarm signal S9 if the voltage of the monitor signal S6 is higher than the comparison voltage S8.

This alarm signal S9 is supplied to the control circuit 9, and is used under the control of the control circuit 9, for example, to drive an alarm.

Further, the alarm signal S9 is supplied to the AND gate 16, and masks the control signal S5 outputted by the control circuit 9 to drive the semiconductor laser oscillator 7. This mask shuts off the switch 17, thereby stopping the power supply from the power supply device 18 to the driver 15 (1). As a result, power supply to the semiconductor laser oscillator 7 is also stopped, and the laser light is turned off.

In this way, since the semiconductor laser oscillator 7 is driven to emit a laser beam when the optical head 6 is surely aligned with the non-information recording area of the optical disc 1, in the unlikely event that the laser drive circuit Even if the light emission output becomes excessive due to a malfunction such as 10, the information recorded in the information recording area a of the optical disc 1 can be prevented from being destroyed.

In addition, the optical disc 1 has reached a predetermined rotation speed, the relative speed between the optical disc 1 and the optical head 6 is a predetermined speed, and the optical head 6 corresponds to the non-information recording area of the optical disc 1. Laser light is emitted when two conditions are met.

This allows a smooth transition to the next process, that is, the focus servo pull-in operation.

Further, the light emission output of the semiconductor laser oscillator 7 is at the comparison voltage S8
If it is within the reference voltage S7, it acts to maintain the predetermined light emission output determined by the reference voltage S7, but if it exceeds the comparison voltage S8, the power supply to the driver 15 is stopped and the light emission output of the semiconductor laser oscillator 7 is stopped. Because I am doing this,
It is possible to prevent information destruction from expanding due to abnormal light emission of the semiconductor oscillator 7.

In the above embodiment, the position detector 8 is provided so as to output the position detection signal S4 when the optical head 6 corresponds to an information-free area, but when the optical head 6 corresponds to an information-free area C,
It may also be provided so as to output the position detection signal S4 when the sensor is moved.

Furthermore, although a case has been described in which the position detector is constituted by a photoink rubber, the position detector is not limited thereto, and may be constituted by a limit switch.

[Effects of the Invention] As described in detail above, according to the present invention, the light emitting means emits a laser beam at a position corresponding to an information-free area of a recording medium, measures the emission output of the laser beam, and detects an abnormality. When light emission is detected, for example, the light emission output is stopped, so it is possible to provide an information recording device that does not destroy information already recorded on the recording medium during initial operation.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a schematic diagram of an optical disk device, Fig. 2 is a diagram showing the mounting position of a position detector, and Fig. 3 is a diagram showing the position of a laser beam output. FIG. 2 is a block diagram showing a control system of FIG. DESCRIPTION OF SYMBOLS 1... Optical disk (recording medium), 2... Spindle motor, 3... Phase comparator, 4... Motor driver, 5... Moving mechanism (moving means), 6... Optical head ( light emitting means), 6a... detection body, 7... semiconductor laser oscillator, 8... position detector (first detection means), 9
...control circuit (first processing means, second processing means),
DESCRIPTION OF SYMBOLS 10... Laser drive circuit, 11... Photoelectric conversion element (second detection means), 12... Amplifier, 13...
Error amplifier, 14...voltage comparator (second detection means)
, 15...driver, 16...AND gate, 17
...Switch, 18...Power supply device. Applicant's representative Patent attorney Takehiko Suzue @1 Figure

Claims (2)

[Claims] (1) A light emitting unit that emits a laser beam to a recording medium having an information recording area and an information non-recording area, and information that records information on the recording medium by controlling the light emission of this light emitting unit. a recording means; a moving means for moving the light emitting means in a radial direction of the recording medium; and a position where the laser beam irradiated by the light emitting means moved by the moving means corresponds to an information-free area of the recording medium. a first detecting means for detecting that the light emitting means is moved by the moving means when the response is not detected by the first detecting means;
when the response is detected by the processing means and the first detection means,
a second processing means for causing the light emitting means to emit laser light; and a light emission output of the laser light from the light emitting means when the laser light is emitted by the light emitting means according to the processing of the second processing means. an information recording device, comprising: second detection means for detecting whether or not there is an abnormality. (2) The information recording device according to claim 1, wherein the recording medium is an optical disc.