Memory disk and apparatus for recording information on memory disk

• US 5,058,089 A
• Filed: 03/01/1990
• Issued: 10/15/1991
• Est. Priority Date: 03/01/1989
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kumagai, Hideo, Yokota, Tsuneshi, Yoshimaru, Tomohisa
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): Tran, Thang V.
• Application Number:
  US07/486,847
• Time in Patent Office: 593 Days
• Field of Search: 369/32, 369/58, 369/53, 369/54, 369/124, 369/111, 369/50, 369/47, 369/48, 360/75, 371/38
• US Class Current: 369/30.21
• CPC Class Codes: G11B 20/1883 Methods for assignment of alternate areas for defective areas
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 7/0045 Recording G11B7/006, G11B7/0065 take precedence
• CPC Class Codes: G11B 7/005 Reproducing G11B7/0065 takes precedence
• CPC Class Codes: G11B 7/0079 Zoned data area, e.g. having different data structures or formats for the user data within data layer, Zone Constant Linear Velocity [ZCLV], Zone Constant Angular Velocity [ZCAV], carriers with RAM and ROM areas

Abstract

An optical disc device includes an optical head for recording/reproducing information to and from an optical disc. The optical disc has two primary recording areas. On a first recording area of the two primary areas, the optical head records information so that the linear density of information is maintained constant. On a second recording area of the two primary areas, the optical head records information so that the spacing between adjacently recorded information increases with increasing radial position of the head or the recording position is further removed from the center of the optical disc. A substitute area is allocated such that the optical head records information in this substitute area when a defective memory portion portion is detected in the first and/or the second recording area during production or recording.

Claims

1. An optical memory device for recording information to an optical memory having first and second radii defined from a center thereof, the optical memory device recording information in response to light irradiated thereon, said device comprising:

motor means for rotating the optical memory at a predetermined constant speed;

head means for recording information on the optical memory;

position detecting means for detecting a radial position of said head means facing the optical memory;

control means for controlling said head means to record information at a predetermined constant spacing when the radial position of said head means detected by said position detecting means is between a first and second predetermined radius from the center of the optical memory and to record information at a spacing which increases with increasing radius as the position of said head means detected by said position detecting means is further from the center of the optical memory when the radial position of said head means detected by said position detecting means is greater than the second predetermined radius from the center of the optical memory;

defect detecting means for detecting a defective memory portion on the optical memory; and

substitute means for recording information to be recorded on the defective memory portion detected by said defect detecting means in a predetermined substitute recording area of the optical memory.

2. The device of claim 1, wherein said head means includes:

clock means for generating clock signals with a plurality of frequencies; and

recording means, in response to the clock signal, for recording information.

3. The device of claim 2, wherein said clock means generates clock signals with frequencies selected such that the frequencies are varied linearly in regard to radius from the center of the optical memory between the first and second predetermined radii.

4. The device of claim 2, wherein said clock means generates clock signals with frequencies selected such that the frequencies are constant in regard to the position of said head means in an area outside the second predetermined radius from the center of the optical memory.

5. The device of claim 2, wherein the clock signals are generated at frequencies corresponding to each track of the optical memory, the track being a unit of recording on the optical memory.

6. The device of claim 5, wherein one frequency is assigned to one track of the optical memory and one frequency of one track is different from that of an adjacent track.

7. The device of claim 6, further comprising a reproducing means for reproducing information recorded by said head means and wherein the difference of frequency is within a predetermined range of values at which said reproducing means may reproduce information.

8. The device of claim 1, wherein said optical memory includes an optical disc that is round and the second predetermined radius is three quarters of the radius of the optical disc.

20. The optical memory device of claim 1 wherein said substitute area is located within said first predetermined radius.

21. The optical memory device of claim 1 wherein said substitute area is located between said first and second predetermined radii.

22. The optical memory device of claim 1 where said substitute area is located partially within said first predetermined radius and partially between said first and second predetermined radii.

9. An optical memory for storing information, in response to light from a head device irradiating said optical memory, by a pit having different optical characteristics from a portion without information on said optical memory, the optical memory having first and second predetermined radii defined from a center thereof and said second predetermined radius being greater than said first predetermined radius, said optical memory comprising:

a first recording area, located between the first predetermined radius and the second predetermined radius on said optical memory, for storing information such that a spacing between adjacent pits is constant;

a second recording area, located outside the second predetermined radius, for storing information such that the spacing between adjacent pits increases with increasing radial position as the position at which the pit is made is further removed from the center of said optical memory; and

a predetermined substitute area for storing information corresponding to a defective memory portion located in said first or second recording areas.

10. The memory of claim 9, wherein said optical memory includes an optical disc that is round and the second predetermined radius is three quarters of the radius of said optical disc.

11. The memory of claim 9, wherein the predetermined substitute area is allocated within the first recording area.

12. A method of recording information to an optical memory which records information in response to light emitted from a head means for recording information on the optical memory which is rotated at a predetermined constant speed during the recording operation, the recording method comprising the steps of:

detecting a radial position of the head means facing the optical memory;

controlling the head means to record information in a first format when the radial position of the head means detected by said detecting step is in a first inner area on the optical memory and recording information in a second format when the radial position of the head means detected by said detecting step is in a second outer area on the optical memory;

detecting a defective memory portion on the optical memory; and

recording information to be recorded in the defective memory portion detected by said defect detecting step on the optical memory in a substitute area on the optical memory.

13. The method of claim 12, wherein said controlling step includes the steps of:

generating clock signals with a plurality of frequencies; and

recording information in response to the clock signals generated by said clock signal generating step.

14. The method of claim 12, wherein said clock generating step includes the step of generating clock signals with frequencies so that the frequencies are linearly increase with increasing radial position of the head means from a center of the optical memory in the first inner area.

15. The method of claim 12, wherein said controlling step includes the step of generating clock signals and controlling said head means in response thereto, said clock signals having frequencies selected such that said frequencies are constant in the second outer area.

16. The method of claim 12, wherein said controlling step includes the step of generating clock signals and controlling said head means in response thereto, said clock generating step including the step of generating clock signals with frequencies selected such that one frequency is assigned to one track of the optical memory and the frequency for one track is different from that for an adjacent track in the first inner area.

17. A method of recording information to and reproducing information from an optical memory, the optical memory recording information in response to light emitted from a head means facing the optical memory for recording information on the optical memory, the optical memory being rotated at a predetermined constant speed during the recording operation, the method comprising the steps of:

detecting the radial position of the head means facing the optical memory;

controlling the head means to record information in a first format when the radial position of the head means detected by said detecting step is in a first inner area on the optical memory and recording information in a second format when the radial position of the head means detected by said detecting step is in a second outer area on the optical memory, wherein the step of controlling said head means includes the step of generating clock signals and controlling said head means in response thereto,

detecting a defective memory portion on the optical memory; and

recording information to be recorded in the defective memory portion detected by said defect detecting step on the optical memory in a substitute area on the optical memory;

subsequently reproducing information recorded on said optical memory wherein the differences in frequency of the clock signals generated by said clock generating step are within a predetermined range of values at which information may be reproduced by said reproducing step.

18. An apparatus for recording information on an optical memory having first and second predetermined radii defined from a center of the optical memory, the second predetermined radius being greater than the first predetermined radius, said apparatus comprising:

motor means for rotating the optical memory at a predetermined constant speed;

head means facing said optical memory for recording information on the optical memory rotated at said predetermined constant speed by said motor means;

position detecting means for detecting a radial position of said head means facing the optical memory;

first head control means for controlling said head means such that a spacing between adjacent pits is constant;

second head control means for controlling said head means such that the spacing between adjacent pits increases with increasing radial position as the position at which the pits are made is further removed from the center of the optical memory;

defect detecting means for detecting a defective memory portion on the optical memory;

substitute means for recording information to be recorded on the defective memory portion detected by said defect detecting means in a predetermined substitute recording area on the optical memory; and

means responsive to the position detecting means for selecting said first or second head control means such that said head means records information in response to said first head control means when the radial position of said head means as detected by said position detecting means is between said first and second predetermined radii, and said head means records information in response to said second head control means when the radial position of said head means as detected by said position detecting means is greater than said second predetermined radius from the center of the optical memory.

19. A method for recording information on an optical memory, the optical memory recording information in response to light emitted from head means for recording information on the optical memory, the optical memory further being rotated at a predetermined constant speed during the recording process, said head means being selectively controlled by one of two control means, the first control means controlling said head means to record information in a first format in which a spacing between adjacent pits is constant, and a second control means controlling said head means to record information in a second format in which the spacing between adjacent pits increases with increasing radial position as the position of said head means is further removed from the center of the optical memory, the recording method comprising the steps of:

detecting the radial position of the head means facing the optical memory;

controlling the head means to record information in a first format when the radial position of the head means detected by said detecting step is in a first area on the optical memory and recording information in a second format when the radial position of the head means detected by said detecting step is in a second area on the optical memory, said second area being located outside the first area on the optical memory;

detecting a defective memory portion on the optical memory; and

recording information to be recorded in the defective memory portion detected by said defect detecting step on the optical memory in a substitute area on the optical memory.