Method for accessing optical disk by detecting the different between moving command and actually moving

A disc playback apparatus, comprising:

• an optical pickup for optically reading information stored in an optical disc;
• an optical pickup moving means for causing said optical pickup to travel in a radial direction of said optical disc;
• a travel amount commanding means for providing a travel amount command to said optical pickup moving means;
• an error detecting means for detecting a travel amount error, said travel amount error comprising the difference between an amount of travel indicated in said travel amount command and an amount of actual travel by said optical pickup;
• and
• a travel amount correcting means for correcting the value of the travel amount command so as to reduce said travel amount error;
• wherein said travel amount command is stored in memory and is dependant on the type of optical disc provided to the disc playback apparatus.

A disc playback apparatus, comprising:

• an optical pickup for optically reading information stored in an optical disc;
• an optical pickup moving means for causing said optical pickup to travel in a radial direction of said optical disc with a travel speed;
• a travel amount commanding means for providing a travel amount command to said optical pickup moving means;
• an error detecting means for detecting a travel amount error, said travel amount error comprising the difference between an amount of travel indicated in said travel amount command and an amount of actual travel by said optical pickup;
• and
• a travel speed setting means operable to alter said travel speed when said travel amount error exceeds a predetermined value;
• wherein said travel speed setting means increases said travel speed when said amount of actual travel is less than said amount of travel indicated in said travel amount command.

A seeking method for a disc playback apparatus having an optical pickup for optically reading information stored in an optical disc, said method comprising the acts of:

• computing a travel amount command that represents the amount to be traveled by said optical pickup in a radial direction of the optical disc;
• detecting a travel amount error, said travel amount error comprising the difference between an amount of travel indicated in said travel amount command and an amount of actual travel by said optical pickup;
• correcting the value of the travel amount command so as to reduce said travel amount error;
• and
• storing the detected values of said travel amount error in relation to the values of said travel amount command that are set at a predetermined pitch.

A seeking method for a disc playback apparatus having an optical pickup for optically reading information stored in a optical disc;

• said method comprising the acts of:
• computing a travel amount command that represents the amount to be traveled by said optical pickup in a radial direction of the optical disc;
• detecting a travel amount error, said travel amount error comprising the difference between an amount of travel indicated in said travel amount command and an amount of actual travel by said optical pickup;
• storing said detected travel amount error in a memory;
• correcting the value of the travel amount command so as to reduce said travel amount error;
• and
• successively updating the content of said memory based on the travel amount error detection results.

A seeking method for a disc playback apparatus having an optical pickup for optically reading information stored in a disc-type storage medium;

• said method comprising the acts of:
• determining an amount to be traveled by said optical pickup in a radial direction of the disc-type storage device;
• detecting a travel amount error in terms of the difference between the amount to be traveled and an amount actually traveled by said optical pickup in accordance with said travel amount command;
• and
• setting, when the travel amount error exceeds a predetermined value, the travel speed of said optical pickup to a high speed if the position of the optical pickup after a travel is still short of a reading position corresponding to the travel amount command, and to a low speed if the position of the optical pickup has overreached the reading position.

A controller for a disc playback apparatus, comprising:

• a memory operable to store a travel amount error;
• a traversed track number computing unit operable to compute a number of tracks to be traversed by an optical pickup;
• a correction processing unit in communication with said traversed track number processing unit and said memory, said correction processing unit operable to provide a corrected amount of tracks to be traversed;
• a track error computing unit in communication with said correction processing unit and operable to detect a travel amount error, said travel amount error comprising the difference between said corrected amount of tracks to be traversed and an amount of tracks actually traversed by said optical pickup;
• and
• a learning process unit in communication with said track error computing unit and said memory, said learning process unit operable to store data received from said track error computing unit in said memory.