Optical recording and reproducing apparatus with abnormality detector

• US 4,800,548 A
• Filed: 06/22/1987
• Issued: 01/24/1989
• Est. Priority Date: 06/20/1986
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Koishi, Kenji, Matsuo, Tamotsu
• Primary Examiner(s): McElheny, Jr., Donald
• Application Number:
  US07/064,605
• Time in Patent Office: 582 Days
• Field of Search: 369/54, 369/116, 369/100, 369/53, 360/31, 346/76 L
• US Class Current: 369/53.18
• CPC Class Codes: G11B 19/04 Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: G11B 7/004 Recording, reproducing or erasing methods; Read, write or erase circuits therefor magneto-optical systems G11B11/105

Abstract

An optical recording and reproducing apparatus which records information on the optical disc to reproduce the information from the optical disc. It is necessary to detect the abnormal condition, when the abnormal condition has been caused while the information is recording on the optical disc, to change the optical power level of the laser light source into the non-recording condition so that the abnormal data may not be recorded on the optical disc. The track skipping which is not intended, unnecessary during the recording operation, the condition which is not the record power with the record power level being set, the motor which is rotating the optical disc causes the abnormal rotation, are the abnormal condition during the recording operation. The diagnosis function is important which confirms the positive operation of the abnormal condition detection during the recording operation, and of the write protection, because the abnormal condition during the recording operation considerably lowers the reliability of the data recorded on the optical disc.

Claims

1. An optical recording and reproducing apparatus comprising an optical recording and reproducing means for focusing a laser light source onto an optical disc to record or reproduce the information, an abnormal record detecting means which detects that the abnormal condition has been caused where the normal record operation cannot be effected when the information is recorded by the optical recording and reproducing means onto the optical disc, a write protecting means for changing from the recording state to the non-recording state the optical power level of the laser light source during the recording operation by said abnormal record detecting means, a diagnostic means for confirming that said abnormal record detecting means and said write protecting means normally operate.

2. An optical recording and reproducing apparatus in accordance with claim 1, wherein the diagnostic means comprises a means for generating artificial write gate signals which do not become under the recording state, an abnormal operation generating means for causing, without changing the optical power level of said laser light source into the recording state the artificial abnormal operation similar to the abnormal condition to be caused at the recording time during the artificial write gate signal generating period, a means for detecting the abnormality detecting signal generated in accordance with the abnormal operation caused by said abnormal operation producing means through said abnormal record detecting means, also for confirming that said write protecting means normally operates in accordance with it.

3. An optical recording and reproducing apparatus in accordance with claim 1, wherein said optical disc has a guide track, said abnormal record detecting means is composed of an abnormal track skip detecting means for detecting by the track crossing signal that the track skipping has been caused to the other guide track from the guide track which is recording the information.

4. An optical recording and reproducing apparatus in accordance with claim 3, wherein the diagnostic means is adapted to confirm the normal operation of the skip detecting means and write protecting means in addition to a means for geenrating the artificial write gate signal which does not become the record condition, a means of starting the normal track jump during the artificial write gate signal generating period to generate the track crossing signal, a track skip detecting means and a write protecting means.

5. An optical recording and reproducing apparatus in accordance with claim 1, wherein the abnormality detecting means is composed of a optical power abnormality detecting means for detecting the abnormal condition where the light power during the recording operation of the laser light source is not the recording power.

6. An optical recording and reproducing apparatus in accordance with claim 5, where the diagnostic means generates the artificial write gate signal which does not become the recording state, causes the artificial optical power abnormal condition similar to the abnormal condition to be caused at the recording time during the artificial write gate signal generating period to generate the optical power abnormality detecting signals to confirm the normal operation of said optical power abnormality detecting means and said write protecting means.

7. An optical recording and reproducing apparatus in accordance with claim 1, wherein the motor driving means for rotating said optical disc is provided, said abnormality detecting means is composed of a motor rotation abnormality detecting means which detects the abnormal condition of the rotation speed or the rotation synchronism of the motor when the information is recorded on said optical disc by said the optical recording and reproducing means.

8. An optical recording and reproducing apparatus in accordance with claim 7, wherein the diagnostic means generates the artificial write gate signal which does not become the recording state, causes the artificial light power abnormal condition similar to the abnormal condition to be caused at the recording time during the artificial write gate signal generating period to generate the motor rotation abnormality signals to confirm the normal operation of said motor rotation abnormality detecting means and said write protecting means.