Hewlett-packard Company

Kraig A Proehl

Thomas Charles Oliver

Mark John Bianchi

Mark E Wanger

Donald J Stavely

Rick A Kato

Leo J Embry

Jennifer L Methlie

Detecting blank sectors in an optical disk is disclosed. Such detection operates by sampling a target data field of a sector on the optical disk and generating a read peak signal based upon the sampling. The read peak signal is then compared to a predetermined amplitude threshold. A counter is incremented if the read peak signal is less than the predetermined amplitude threshold. After the above steps are performed a predetermined number of times, the counter is compared to a predetermined sample threshold value. Then, the sector is interpreted as being blank if the counter is greater than the predetermined sample threshold value. If, instead, the counter is less than the predetermined sample threshold value, then the sector is interpreted as being non-blank.

Blank sector detection for optical disk drive

Disclosed is an optical disk handling system, called an autochanger, having two control systems to provide the six motions necessary to move optical disk cartridges from storage holding cells to an optical drive. The system uses shaft encoders on two motors of the two control systems, and current or voltage feedback from the motors, for all positioning, and for detecting the location of the mechanisms during, and at the end of, moves. An optical drive interface connects the electronics of the autochanger and the optical drive, and includes electrical signals to emulate an eject pushbutton on the optical drive and an indicator lamp on the optical drive. The autochanger monitors the on and off state of the lamp signal as well as the duration of the on and off cycles to determine which operation is being performed by the optical drive. The autochanger uses the lamp signal and the eject signal to control all operations with the optical drive.

Input/output communication between autochanger and drive

Disclosed is an optical disk handling system having two control systems to provide the motions necessary to move optical disk cartridges form storage holding cells to an optical drive. During initialization, the cartridge handling system uses shaft encoders, along with current or voltage feedback from the motors, to calibrate the home locations of the mechanisms. The system determines the home position for vertical movement of the transport as well as the top and bottom positions used for the translate operation. The system then calibrates the plunge movement, the flip movement, and the translate movement. Finally, the system determines whether the path for all the movements is free of obstructions.

Calibration of a cartridge handling device using mechanical sense of

Disclosed is an optical disk handling system, called an autochanger, having two control systems to provide the six motions necessary to move optical disk cartridges from storage holding cells to an optical drive. Whenever the mechanisms are being moved, the control systems monitor the progress of the movement, and should the control system detect an error conditon, a state update flag is changed to prevent further updates of the state of the system. With state updates disabled, the control system will stop all mechanisms and prevent further movement of the mechanisms. When the operation appears complete, an error recovery software function is called. When the error recovery software detects that the state update flag is in an error condition, error recovery is initiated. After the mechanism's state has been established, error recovery movement is started, based on the operation that was being performed at the time of the error, and the state of the machine at the time of the error. The type operation being performed is saved in non-volatile memory, so that the type of operation will be saved should electrical power fail during the operation. Therefore, after power is restored, power fail error recovery can perform error recovery based on the type of operation being attempted at the time power was lost.

Error recovery in a cartridge handling system

Disclosed is an optical disk handling system having two control system to provide the motions necessary to move optical disk cartridges from storage holding cells to an optical drive. During initialization, the cartridge handling system uses shaft encoders, along with current or voltage feedback from the motors, to calibrate the home locations of the mechanisms. The system determines the home position for vertical movement of the transport as well as the top and bottom positions used for the translate operation. The system then calibrates the plunge movement, the flip movement, and the translate movement. Finally, the system determines whether the path for all the movements is free of obstructions.

Disclosed is an optical disk handling system, called an autochanger, having two control systems to provide the six motions necessary to move optical disk cartridges from storage holding cells to an optical drive. The system uses shaft encoders on the motors of the two control systems, and current or votlage feedback from the motors, for all positioning, and for detecting the location of the mechanisms during and at the end of moves. The shaft encoders are used to position a mechanism close to the eventual move location, then motor current or voltage feedback is used to determine opposition to the movement to the mechanism, which informs the control system as to whether the mechanism has reached its destination. An important aspect of the invention is that the motor current or voltage feedback is used by one control system to provide five of the six motions.

Mechanical sense of touch in a control system

A tape drive system employs position capture circuitry to facilitate accurate positioning of the tape media. The position capture circuitry includes an input polling state machine (101) to ensure each detection results in exactly one position value transfer. A timing section (103) synchronizes the polling of inputs with data transfers. A bus multiplexing section (105) provides for 12-bit resolution over 8-bit busses. The position types can be data block boundaries or reel-encoder marks or position requests by the servo controller. The input lines (41-44) are polled routinely, ensuring that the stored values precisely reflect the referenced positions.

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Loveland, CO, United States of America

Kraig A Proehl