1. A method of detecting a crack in a disc loaded on a disc drive, the method comprising:
determining whether the disc drive satisfies an initially set condition for execution of a disc crack detection algorithm;
counting a number of tracking error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods, in response to determining that the disc drive satisfies the initially set condition; and
generating a disc crack detection signal when the number of counted tracking error signals exceeds a predetermined number.
2. The method of claim 1, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever a play mode is changed into a pause mode.
3. The method of claim 1, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed at predetermined time intervals in a pause mode.
4. The method of claim 1, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever a target speed of the disc drive is changed.
5. The method of claim 4, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever the target speed increases.
6. The method of claim 1, further comprising transmitting warning message data to a host computer when the disc crack detection signal is generated.
7. A method of detecting a crack in a disc loaded on a disc drive, the method comprising:
determining whether the disc drive satisfies an initially set condition for execution of a disc crack detection algorithm;
counting a number of focus error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods, in response to determining that the disc drive satisfies the initially set condition; and
generating a disc crack detection signal when the number of counted focus error signals exceeds a predetermined number.
8. The method of claim 7, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever a play mode is changed into a pause mode.
9. The method of claim 7, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed at predetermined time intervals in a pause mode.
10. The method of claim 7, wherein the condition for execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever the target speed of the disc drive is changed.
11. The method of claim 7, wherein the condition of execution of the disc crack detection algorithm is set such that the disc crack detection algorithm is performed whenever the target speed of the disc drive increases.
12. The method of claim 7, further comprising transmitting warning message data to a host computer when the disc crack detection signal is generated.
13. A method of controlling the speed of a disc drive, comprising
determining whether a command instructing changing of a speed of the disc drive to a target speed is input;
controlling a speed of a spindle motor to be the target speed according to the command;
counting a number of tracking error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods until the current speed reaches the target speed;
generating a disc crack detection signal when the number of counted tracking error signals exceeds a predetermined number; and
changing the target speed into a predetermined low speed when the disc crack detection signal is generated.
14. A method of controlling the speed of a disc drive, comprising the operations of:
determining whether a command instructing changing of a speed of the disc drive to a target speed is input;
controlling a speed of a spindle motor to be the target speed according to the command;
counting a number of focus error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods until the current speed reaches the target speed;
generating a disc crack detection signal when the number of counted focus error signals exceeds a predetermined number; and
changing the target speed into a predetermined low speed when the disc crack detection signal is generated.
15. A method of controlling the speed of a disc drive, comprising
determining whether a current play mode is changed into a pause mode;
counting a number of tracking error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods, in response to determining that the play mode is changed into the pause mode;
generating a disc crack detection signal when the number of counted tracking error signals exceeds a predetermined number; and
changing a target speed into a predetermined low speed when the disc crack detection signal is generated.
16. A method of controlling the speed of a disc drive, comprising:
determining whether a current play mode is changed into a pause mode;
counting a number of focus error signals whose levels exceed a predetermined threshold voltage, at predetermined measuring time periods, in response to determining that the play mode is changed into the pause mode;
generating a disc crack detection signal when the number of counted focus error signals exceeds a predetermined number; and
changing a target speed into a predetermined low speed when the disc crack detection signal is generated.
17. A method of controlling a disc drive in which a disc is loaded, the method comprising:
determining whether a crack exists in the disc; and
lowering a target speed of the disc drive in response to determining that the crack exists in the disc.
18. The method of claim 17, wherein the determining comprises:
counting a number of tracking error signals or focusing error signals whose levels exceed respective predetermined threshold values, at predetermined time intervals; and
determining that the crack exists if the counted number in one of the predetermined measuring time periods exceeds a predetermined number.
19. The method of claim 17, wherein the determining comprises determining whether the crack exists in response to a play mode changing into a pause mode.
20. The method of claim 17, wherein the determining comprises determining whether the crack exists at predetermined time intervals in a pause mode.
21. The method of claim 17, wherein the determining comprises determining whether the crack exists in response to the target speed changing.
22. A method of detecting a crack in a disc loaded on a disc drive, the method comprising:
determining levels of tracking error signals or focusing error signals for predetermined time periods; and
comparing the levels of the tracking error signals or the focusing error signals to a threshold value to determine whether the crack exists.
23. The method of claim 22, wherein the comparing comprises:
counting a number of tracking error signals whose levels exceed the predetermined threshold value within the predetermined time periods; and
determining that the crack exists when the number of tracking error signals within one of the predetermined time periods exceeds a predetermined number.
24. The method of claim 22, wherein the comparing comprises:
counting a number of focusing error signals whose levels exceed the predetermined threshold value within the predetermined time periods; and
determining that the crack exists when the number of focusing error signals within one of the predetermined time periods exceeds a predetermined number.
25. The method of claim 17, wherein the comparing comprises comparing the levels in response to a play mode changing into a pause mode.
26. The method of claim 17, wherein the comparing comprises comparing the levels at predetermined time intervals in a pause mode.
27. The method of claim 17, wherein the comparing comprises comparing the levels in response to the target speed changing.
28. A program stored on a computer readable medium for performing a method of detecting a crack in a disc loaded on a disc drive, the method comprising:
determining levels of tracking error signals or focusing error signals for predetermined time periods; and
comparing the levels of the tracking error signals or the focusing error signals to a threshold value to determine whether the crack exists.
29. A system that determines whether a crack in a disc loaded on a disc drive exists, comprising:
storing a variety of execution programs in a storage medium to drive a disc drive at different speeds;
counting the number of tracking error signals or focus level signals for predetermined time periods;
determining whether a crack exists from the number of tracking error signals or focus error signals counted; and
retrieving one of said variety of execution programs to control the speed of said disc drive depending on whether a crack is determined to exist.
30. The system according to claim 29, wherein said determining comprises comparing the counted number of tracking error signals or focus error signals with a predetermined threshold value.
31. The system according to claim 30, wherein if it is determined that a crack exists, retrieving an execution program which lowers a target speed of the disc drive.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus for joining a first member and a second member, comprising:
means for joining the first member and the second member;
means for transferring shear loads between the first member and the second member separate from the means for joining the first member and the second member; and
means for providing a compression preload to the means for transferring shear loads between the first member and the second member.
2. The apparatus, according to claim 1, wherein the means for joining the first member and the second member comprises:
a fastener disposed through a fastener hole defined by the first member and the second member.
3. The apparatus, according to claim 1, wherein the means for joining the first member and the second member comprises:
at least one clip engaged with the first member and the second member.
4. The apparatus, according to claim 1, wherein the means for joining the first member and the second member comprises:
at least one fastening element extending from the first member and bent about the second member.
5. The apparatus, according to claim 1, wherein the means for joining the first member and the second member comprises:
a cable operably associated with the first member and the second member.
6. The apparatus, according to claim 1, wherein the means for transferring shear loads between the first member and the second member comprises:
a shear transfer layer adhesively bonded to the first member and the second member.
7. The apparatus, according to claim 1, wherein the means for transferring shear loads between the first member and the second member comprises:
an adhesive layer bonding the first member to the second member.
8. The apparatus, according to claim 1, wherein the means for transferring shear loads between the first member and the second member comprises:
a feature of at least one of the first member and the second member mechanically interlocking the first member and the second member.
9. The apparatus, according to claim 1, wherein the means for providing the compression preload to the means for transferring shear loads between the first member and the second member comprises:
a biasing element operably associated with at least one of the first member and the second member.
10. The apparatus, according to claim 1, wherein the means for providing the compression preload to the means for transferring shear loads between the first member and the second member comprises:
a deformation of at least one of the first member and the second member, such that, when the deformation is substantially removed, the at least one of the first member and the second member provides the compressive preload to the means for transferring shear loads between the first member and the second member.
11. An assembly, comprising:
a first member;
a second member;
means for joining the first member and the second member;
means for transferring shear loads between the first member and the second member separate from the means for joining the first member and the second member; and
means for providing a compression preload to the means for transferring shear loads between the first member and the second member.
12. The assembly, according to claim 11, wherein the means for joining the first member and the second member comprises:
a fastener disposed through a fastener hole defined by the first member and the second member.
13. The assembly, according to claim 11, wherein the means for joining the first member and the second member comprises:
at least one clip engaged with the first member and the second member.
14. The assembly, according to claim 11, wherein the means for joining the first member and the second member comprises:
at least one fastening element extending from the first member and bent about the second member.
15. The assembly, according to claim 11, wherein the means for joining the first member and the second member comprises:
a cable operably associated with the first member and the second member.
16. The assembly, according to claim 11, wherein the means for transferring shear loads between the first member and the second member comprises:
a shear transfer layer adhesively bonded to the first member and the second member.
17. The assembly, according to claim 11, wherein the means for transferring shear loads between the first member and the second member comprises:
an adhesive layer bonding the first member to the second member.
18. The assembly, according to claim 11, wherein the means for transferring shear loads between the first member and the second member comprises:
a feature of at least one of the first member and the second member mechanically interlocking the first member and the second member.
19. The assembly, according to claim 11, wherein the means for providing the compression preload to the means for transferring shear loads between the first member and the second member comprises:
a biasing element operably associated with at least one of the first member and the second member.
20. The assembly, according to claim 11, wherein the means for providing the compression preload to the means for transferring shear loads between the first member and the second member comprises:
a deformation of at least one of the first member and the second member, such that, when the deformation is substantially removed, the at least one of the first member and the second member provides the compressive preload to the means for transferring shear loads between the first member and the second member.
21. An assembly, comprising:
a first member;
a second member;
a joining element joining the first member and the second member;
a shear load transfer structure operably associated with the first member and the second member separate from the joining element; and
a compression preload feature providing a compression preload to the shear load transfer structure.