JP2578719Y2 - Optical disk recording device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording device, and more particularly to a write-once optical disk recording device.

[0002]

2. Description of the Related Art For example, in a write-once optical disk recording apparatus, information is recorded by irradiating a laser beam to an optical disk to change the dye of a recording medium formed on the surface of the optical disk. Is irradiated with laser light, and a change in reflected light level is detected to detect recorded information. In a conventional write-once optical disc recording device,
There is no means for determining in real time whether or not the recording on the optical disk recording medium has been normally performed during the writing, and it has been confirmed by performing a reproducing operation after the end of the writing (recording).

[0003]

As described above, the conventional write-once type optical disk recording apparatus can confirm in real time whether or not information has been normally recorded on an optical disk recording medium during writing. Can not. However,
Dirt such as dust and fingerprints often adhere to the optical disk surface, and in such a case, the irradiation laser light may not reach the dye of the recording medium on the optical disk surface, or the laser light may be reflected by the dirt. Normal writing may be partially impossible. When an optical disk on which abnormal writing has been performed due to such contamination is reproduced, problems such as a burst error, noise generation, and sound skipping occur.

Further, dirt such as dust and fingerprints adhering to the surface of the optical disk acts as an internal disturbance to the tracking servo system of the device, causing sound skipping during recording, but is monitored during recording. Because there is no, you can discover abnormalities only after playing. However, a write-once optical disc recording device cannot record data on a recording medium once by irradiating a laser beam. There is also a problem.

Therefore, an object of the present invention is to provide an optical disk recording apparatus which can determine the quality of recording in real time during information recording and uses the optical disk effectively.

[0006]

In order to solve the above-mentioned problems, an optical disk recording apparatus according to the present invention, when recording information on an optical disk, forms a pit by irradiating a high-power laser beam when forming the pit, In an optical disc recording apparatus for detecting information from an optical disc by irradiating a low-power laser beam when pits are not formed, an average value circuit for detecting an average value of reflected light from the optical disc when forming pits as an average reflected light. A comparator that compares the reflected light from the optical disc when forming a pit with the output value of the average circuit; and that the state in which the reflected light when forming the pit is greater than or equal to the average reflected light based on the output of the comparator. Determining means for determining whether or not the operation is continued for a predetermined time or more from the start, and detecting an abnormal state based on an output of the determining means. Another aspect of the optical disc recording device according to the present invention is as follows.
When recording information on an optical disk, an optical disk recording device that irradiates high-power laser light when forming pits to form pits, and irradiates low-power laser light when non-pits are formed to detect information from the optical disk A time information detecting means for detecting ATIP time information from a reflected light signal from the optical disc; a time information generating means for generating time information calibrated each time recording is started; the time information detecting means and the time information A coincidence determining means for detecting a mismatch of the time information from the generating means; and detecting an abnormal state based on an output of the coincidence determining means.

[0007]

According to the invention, the peak level duration of the reflected light from the optical disk is detected, and when the detected peak level duration is equal to or longer than a predetermined time, or the ATip time information is obtained from the reflected light signal from the optical disk. Detect
By outputting an abnormality detection signal when a mismatch with the calibrated time information occurs at the start of recording, the quality of recording during information recording can be determined in real time.

[0008]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an optical disk recording apparatus according to the present invention. FIG. 2 shows the signals of the respective parts of FIG. The recording information EFM signal (A in FIG. 2) is modulated by a laser modulator 3 and a laser beam is irradiated onto the surface of the optical disk 1 via an optical pickup 2 to record information. At this time, the optical pickup 2 receives the reflected light from the optical disc 1 and sends it to the RF amplifier 4. The RF amplifier 4 receives a signal from the pickup 2 and generates a high-frequency signal.

In the present invention, it is determined by the following processing whether or not normal recording has been performed based on the reflected light signal from the optical disk thus obtained. Normally, as shown in FIG. 3, the level of the reflected light from the optical disk rises at the moment when the irradiation laser light level becomes high, but the dye of the recording medium on the surface of the optical disk is changed by the irradiation laser light. Then, the irradiation laser light is absorbed and the reflected light level decreases. Therefore, the peak period of the reflected light is detected, and the recording state can be determined based on the length of the period. For example, if there is dust on the optical disc surface,
Since the laser light does not reach the dye layer of the recording medium and is totally reflected, the peak level does not change and the peak state continues as shown in FIG. When a fingerprint adheres to the surface of the optical disk, the irradiated laser beam is partially absorbed by the fingerprint portion, so that the level of the reflected light is smaller than that in the normal state, as shown in FIGS. As such, small levels persist. By monitoring the change and the state of the peak level of the reflected light from the optical disk, the recording state can be determined and confirmed.

In FIG. 1, an RF signal (B in FIG. 2) from an RF amplifier 4 is supplied to a reference voltage generating circuit 5, a comparator 6, and an ATip decoder 8. The reference voltage generating circuit 5 is a circuit for generating a reference voltage serving as a comparison reference in the comparator 6. In this embodiment, a peak value and an average value of the RF signal are detected, and the reference voltage is substantially at the center of the peak of the RF signal waveform. It is set to become. Therefore, a peak detection circuit 51 for detecting the peak of the RF signal,
An average value detection circuit 52 for detecting the average value of the RF signal, a multiplication circuit 53 for doubling the average value from the average value detection circuit 52,
An average value detection circuit 54 is provided for detecting the average value of both signals based on the peak signal from the peak detection circuit 51 and the signal from the multiplication circuit 53.

The comparator 6 detects a peak waveform of the RF signal waveform, and extracts a level component of the RF signal B which is higher than the reference voltage from the reference voltage generating circuit 5 and outputs it as a signal C (stop signal). 7 The abnormality detection circuit 7 detects an abnormal state of information recording based on the RF signal, and starts generating a sawtooth signal at the rising edge of the EFM signal A (that is, the EF signal A is used as a start signal). A sawtooth wave generating circuit 71 for resetting the generation of the sawtooth wave signal by the stop signal C from the comparator 6, a reference voltage generator 72 for outputting a predetermined abnormality detection comparator voltage, and a sawtooth wave generating circuit 71 The sawtooth signal D is compared with the comparator voltage from the reference voltage generator 72, and when the sawtooth signal D is higher than the comparator voltage, an abnormality detection output (abnormal signal) E indicating an abnormality is generated. And a comparator 73.

That is, in this embodiment, if the time from the generation of the sawtooth wave by the RF signal B to the generation of the stop signal C from the comparator 6 is long, it is determined that the recording is abnormal. Therefore, in the case of the reflected light as shown in FIGS. 4 and 5, the generation of the stop signal is delayed or the stop signal is not generated, and it is determined that the light is abnormal. The notification of the abnormality may be made when a plurality of abnormality detection outputs are generated. because,
This is because, if there is no abnormal change in data for at least one continuous frame, no error occurs during reproduction due to error correction or interpolation.

The ATip decoder 8 decodes the time information of the optical disk 7 from the RF signal from the RF amplifier 4 and sends it to the coincidence circuit 12. The reference time generator 11 supplies the time information generator 10 with a reference time serving as a reference for the time information. The time information generating device 10 includes a reference time generating device 11
From the reference time information received through the switch 9
The time information obtained based on the ATip time information from the Tip decoder 8 is sent to the matching circuit 12. Switch 9
Is for setting the time information of ATip in the time information generating device 10 in synchronization with the start of recording.

The coincidence circuit 12 is a coincidence detection circuit comprising an EX-OR (exclusive OR) circuit and the like, and generates an abnormality detection output when the ATip decoder 8 and the time information from the time information generator 10 do not match. I do. Normally, in the normal recording state, the two input time information to the coincidence circuit 12 match, but if a track is skipped (sound skipping) even one track, the two time information will not match. Sound skipping can be determined. Also in this case, the actual abnormality notification is
This is performed when the abnormality detection output from the coincidence circuit 12 is output several times in succession, and prompts the recording to be stopped, for example.
After that, a mismatch error signal always occurs.
According to the Orange Book Part II, which is a write-once standard, a skip (SKIP) command can be used.
The recording can be reproduced by skipping the defective recording portion.

[0015]

As described above, the optical disk recording apparatus according to the present invention monitors abnormal recording in real time based on the reflected light signal from the optical disk, and can effectively utilize the recording medium area of the optical disk.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optical disc recording apparatus according to the present invention.

FIG. 2 is a timing chart of signal waveforms at various parts in the embodiment of FIG. 1;

FIG. 3 is a diagram showing a level change of reflected light from an optical disk.

FIG. 4 is a diagram showing a change in the level of reflected light from a portion of the optical disc to which dust adheres.

FIG. 5 is a diagram showing a change in the level of reflected light from a portion of the optical disc where a fingerprint is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Pickup 3 Laser modulator 4 RF amplifier 5 Reference voltage generation circuit 6 Comparator 7 Abnormality detection circuit 8 ATip decoder 9 Switch 10 Time information generator 11 Reference time generator 12 Matching circuit

Claims (2)

(57) [Scope of request for utility model registration] When recording information on an optical disk, a pit is formed by irradiating a high-power laser beam when forming the pit.
In addition, in an optical disc recording device that detects information from an optical disc by irradiating a low-power laser beam when pits are not formed, an average value circuit that detects an average value of reflected light when forming pits from the optical disc as an average reflected light A comparator for comparing the reflected light from the optical disc when forming pits with the output value of the average circuit; and a state in which the reflected light during pit formation is equal to or greater than the average reflected light by the output of the comparator. An optical disc recording apparatus, comprising: a determination unit configured to determine whether or not to continue for a predetermined time or more from the start, and detecting an abnormal state based on an output of the determination unit. 2. When information is recorded on an optical disk, a pit is formed by irradiating a high-power laser beam at the time of pit formation.
An optical disc recording apparatus for detecting information from an optical disc by irradiating a low-power laser beam when a pit is not formed; a time information detecting means for detecting ATIP time information from a reflected light signal from the optical disc; Time information generating means for generating time information calibrated for each time, comprising: a time information detecting means; and a coincidence determining means for detecting a mismatch of time information from the time information generating means. An optical disk recording device for detecting an abnormal state.