Optical disk drive

• US 20020048237A1
• Filed: 09/28/2001
• Published: 04/25/2002
• Est. Priority Date: 09/29/2000
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Ishida, Hiroki, Suzuki, Yoshihisa, Tanaka, Sayoko, Noguchi, Hitoshi
• Granted Patent: US 7,280,446 B2
• Time in Patent Office: Days
• US Class Current: 369/44.29
• CPC Class Codes: G11B 11/10576 with provision for moving the transducers for maintaining alignment or spacing relative to the carrier
• CPC Class Codes: G11B 11/10595 Control of operating function
• CPC Class Codes: G11B 7/094 Methods and circuits for servo offset compensation
• CPC Class Codes: G11B 7/0945 Methods for initialising servos, start-up sequences
• CPC Class Codes: G11B 7/126 Circuits, methods or arrangements for laser control or stabilisation

Abstract

There is provided an optical disk drive capable of appropriately effecting recording and reproducing operations without being affected by offset values and a laser output value, which are set at startup of the disk drive, even when changes have arisen in the internal temperature of the disk drive because of changes in ambient temperature. In an optical disk drive, a temperature sensor provided on a pickup measures a temperature. When changes in temperature are greater than a predetermined level, a focus offset value, a tracking offset value, and a value of laser output from the pickup are reset.

Claims

1. An optical disk drive comprising:

temperature measurement means for measuring an internal temperature of the optical disk drive; and

resetting means which resets offset values and/or a laser output value in accordance with changes in the temperature measured by the temperature measurement means.

2. The optical disk drive claim 1, wherein the offset values include a focus offset value and/or a tracking offset value.

3. An optical disk drive comprising:

temperature measurement means for measuring an internal temperature of the optical disk drive;

determination means for determining whether or not the level of change in the temperature measured by the temperature measurement means has exceeded a predetermined level; and

offset value resetting means which resets a focus offset value and/or a tracking offset value when the determination means determines that the level of change in temperature has exceeded a predetermined level.

4. An optical disk drive comprising:

temperature measurement means for measuring an internal temperature of the optical disk drive;

determination means for determining whether or not the level of change in the temperature measured by the temperature measurement means has exceeded a predetermined level;

offset value resetting means which resets a focus offset value and/or a tracking offset value when the determination means determines that the level of change in temperature has exceeded a predetermined level; and

laser output resetting means which resets a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, when the determination means determines that the level of temperature change has exceeded a predetermined level.

5. The optical disk according to claim 4, wherein the optical disk drive further has storage means for storing temperature data pertaining to a relationship between a temperature and a laser output value;

and

the laser output resetting means performs resetting operation in accordance with the temperature table when the laser output resetting means resets the laser output value.

6. The optical disk according to claim 5, wherein a relationship between a temperature and a laser output value for a recording operation and that for a reproducing operation are provided in the temperature table.

7. An optical disk drive comprising:

temperature measurement means for measuring an internal temperature of the optical disk drive;

determination means for determining whether or not the level of change in the temperature measured by the temperature measurement means has exceeded a predetermined level; and

laser output resetting means which resets a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, when the determination means determines that the level of temperature change has exceeded a predetermined level.

8. The optical disk according to claim 7, wherein the optical disk drive further as storage means for storing temperature data pertaining to a relationship between a temperature and a laser output value;

and

the laser output resetting means performs resetting operation in accordance with the temperature table when the laser output resetting means resets the laser output value.

9. The optical disk according to claim 8, wherein a relationship between a temperature and a laser output value for a recording operation and that for a reproducing operation are provided in the temperature table.

10. An optical disk drive comprising:

setting means for setting a focus offset value and/or a tracking offset value at startup of the optical disk drive;

first temperature measurement means for measuring an internal temperature of the optical disk drive at startup of the optical disk drive;

second temperature measurement means for measuring an internal temperature the optical disk drive after startup of the optical disk drive;

determination means for determining whether or not a difference between the temperature measured by the second temperature measurement means and the temperature measured by the first temperature measurement means has exceeded a predetermined level; and

resetting means for resetting the focus offset value and/or the tracking offset value set by the setting means when the determination means determines that the difference has exceeded the predetermined level.

11. The optical disk drive according to claim 10, wherein the second temperature measurement means measures a temperature at predetermined times;

the determination means determines whether or not a difference between a temperature most recently measured by the second temperature measurement means and an immediately preceding temperature measured by the second temperature measurement means has exceeded a predetermined level; and

resetting means resets a set focus offset value and/or a set tracking offset value when the determination means determines that the difference has exceeded the predetermined level.

13. The optical disk drive according to claim 12, wherein the second temperature measurement means measures a temperature at a predetermined time;

the determination means determines whether or not a difference between a temperature most recently measured by the second temperature measurement means and an immediately preceding temperature measured by the second temperature measurement means has exceeded a predetermined level; and

the resetting means resets a set laser output value when the determination means determines that the difference has exceeded the predetermined level.

15. The optical disk drive according to claim 14, wherein the offset values include a focus offset value and/or a tracking offset value.

17. The optical disk drive according to claim 16, wherein the temperature sensor is mounted on the exterior surface of a pickup provided in the optical disk drive.

20. The optical disk drive according to claim 19, wherein the temperature table includes a relationship between a temperature and a laser output value for a recording operation and that for a reproducing operation.

12. An optical disk drive comprising:

setting means for setting a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, at startup of the optical disk drive;

first temperature measurement means for measuring an internal temperature of the optical disk drive at startup thereof;

second temperature measurement means for measuring an internal temperature of the optical disk drive after startup thereof;

determination means for determining whether or not a difference between the temperature measured by the second temperature measurement means and the temperature measured by the first temperature measurement means has exceeded a predetermined level; and

resetting means for resetting the laser output value set by the setting means when the determination means determines that the difference has exceeded the predetermined level.

14. An optical disk drive comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for resetting offset values and/or a laster output value in accordance with changes in the temperature detected by the temperature sensor.

16. An optical disk drive comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for resetting offset values and/or a laser output value in accordance with changes in the temperature detected by the temperature sensor, wherein

the controller determines whether or not the level of change in the temperature measured by the temperature sensor has exceeded a predetermined level and resets a focus offset value and/or a tracking offset value when the level of temperature change is determined to have exceeded the predetermined level.

18. An optical disk drive comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for setting a focus offset value and/or a tracking offset value and setting a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, wherein the controller determines whether or not the level of change in the temperature measured by the temperature sensor has exceeded a predetermined level and resets the focus offset value and/or the tracking offset value and the laser output value when the level of temperature change is determined to have exceeded the predetermined level.

19. The optical disk drive according to 18, wherein

the optical disk drive has memory for storing a temperature table showing a relationship between a temperature and a laser output value;

and

the controller resets the laser output value in accordance with the temperature table.

21. An optical disk drive comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for setting a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, wherein

the controller determines whether or not the level of change in the temperature measured by the temperature sensor has exceeded a predetermined level and resets the laser output value when the level of temperature change is determined to have exceeded the predetermined level.

22. The optical disk according claim 21, wherein the optical disk drive further comprises memory having stored therein a temperature table showing a relationship between a temperature and a laser output value;

and

the controller resets the laser output value in accordance with the temperature table.

23. The optical disk according to claim 22, wherein the temperature table includes a relationship between a temperature and a laser output value for a recording operation and that for a reproducing operation.

25. The optical disk drive according to claim 24, wherein the controller measures the temperature detected by the temperature sensor at given times, determines whether or not a difference between a most-recently measured temperature and a measured temperature preceding the most-recently measured temperature has exceeded a predetermined level, and resets a set focus offset value and/or a set tracking offset value when the difference is determined to have exceeded a predetermined value.

27. The optical disk drive according to claim 26, wherein the controller measures the temperature detected by the temperature sensor at given times, determines whether or not a difference between a most-recently measured temperature and a measured temperature preceding the most-recently measured temperature has exceeded a predetermined level, and resets a set laser output value when the difference is determined to have exceeded a predetermined value.

24. An optical disk drive comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for setting a focus offset value and/or a tracking offset value, wherein

the controller sets a focus offset value and/or tracking offset value at startup of the optical disk drive, determines whether or not a difference between a temperature measured by the temperature sensor at startup of the optical disk drive and a temperature measured by the temperature sensor after startup of the optical disk drive has exceeded a predetermined level, an resets the focus offset value and/or the tracking offset value when the difference is determined to have exceeded the predetermined level.

26. An optical disk drive, comprising:

a temperature sensor for sensing an internal temperature of the optical disk drive; and

a controller for setting a laser output value of a light-emitting section, the laser being output from the light-emitting section for recording and/or reproducing data on and/or from an optical disk, wherein

the controller sets the laser output value at startup of the optical disk drive, determines whether or not a difference between a temperature measured by the temperature sensor at startup of the optical disk drive and a temperature measured by the temperature sensor after startup of the optical disk drive has exceeded a predetermined level, and resets the laser output value when the difference is determined to have exceeded the predetermined level.