Dynamic information storage or retrieval – Control of storage or retrieval operation by a control... – Mechanism control by the control signal
Reexamination Certificate
2001-07-02
2003-02-25
Hindi, Nabil (Department: 2653)
Dynamic information storage or retrieval
Control of storage or retrieval operation by a control...
Mechanism control by the control signal
C369S116000
Reexamination Certificate
active
06526014
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to an optical storage apparatus using a removable medium such as magnetooptical cartridge, phase-change type optical disk, DVD-RAM, or the like and, more particularly, to an optical storage apparatus for executing an access of a command while deciding an optimum light emitting power by a test writing on a medium when receiving a host command.
An optical disk has been highlighted as a storage medium serving as a core of multimedia which has rapidly been developed in recent years. For example, in case of an MO cartridge of 3.5 inches, in addition to conventional medium of 128 MB, medium of a high-density recording of 540 MB or 640 MB has also been being presented in recent years. In the MO cartridge which is used in an optical disk drive, a ZCAV recording (zone constant angular velocity recording) in which a medium track is divided into zones and the number of sectors is set to be equal every zone is used. The medium of 128 MB uses the recording method of a pit position modulation (PPM). It is sufficient that the light emitting power changes at three stages of a reading power, an erasing power, and a recording power. On the other hand, the media of 230 MB, 540 MB, and 640 MB use the recording method of a pulse width modulation (PWM) in order to raise a recording density. In the PWM recording, it is necessary to change the light emitting power at four stages of the reading power, the erasing power, a first writing power, and a second writing power. In the PWM recording of a medium of a direct overwrite corresponding type which doesn't need the erasing operation, it is necessary to change the light emitting power at four stages of the reading power, an assisting power, the first writing power, and the second writing power.
However, in the recording medium of a high density such as 540 MB or 640 MB in which the PWM recording is performed, a margin of an optimum writing power of a laser diode which is used for medium recording is narrow. When a temperature of the medium changes, the optimum writing power changes. The optimum writing power also changes depending on manufacturing conditions of the medium or a difference of writing performance of the optical disk drive. That is, in case of recording by a predetermined writing power which was unconditionally determined at a designing stage, the writing power largely deviates from the actual optimum writing power and a case where the recording operation cannot be executed occurs, so that there is a problem that writing and reading performance deteriorates.
SUMMARY OF THE INVENTION
According to the invention, there is provided an optical storage apparatus constructed in a manner such that even when there is a difference of performance of apparatuses or manufacturing conditions of media or when an apparatus temperature changes, an optimum writing power can always be set and, further, even when it takes a long time for a process to set the optimum power, an error due to a time-out doesn't occur for an upper apparatus.
An optical storage apparatus of the invention comprises: a tight emitting power adjusting unit for adjusting a light emitting power of a laser diode which is used for recording and reproduction of a medium; and a division test writing processing unit for dividing a test writing process to an optimum light emitting power by executing a test writing on the medium into a plurality of processes and for sequentially executing the divided processes each time an upper command is received. By the division test writing process as mentioned above, a series of test writing processes accompanied with the erasing, writing, and reading operations (in the direct overwrite corresponding type medium which doesn't need the erasing operation, the test writing process for writing and reading) when the upper command is received are divided into a plurality of processing stages and are sequentially executed. Even when the apparatus temperature rapidly changes and the optimum power remarkably deviates from the default power which has initially been set and it takes a long time up to the end of the test writing operation to find the optimum power, since the processes are distributed and executed, a time-out for the upper command doesn't occur and the recording and reproducing operations can be executed as much as possible even when the power is deviated from the optimum power, so that the apparatus performance is improved.
An optical storage apparatus of the invention comprises: a light emitting power adjusting unit for adjusting a light emitting power of a laser diode which is used for recording and reproduction of a medium; and a division test writing processing unit for dividing a test writing, process to determine an optimum light emitting power by executing a test writing on the medium into a plurality of processes and for sequentially executing the divided processes each time an upper command is received. By the division test writing process as mentioned above, a series of test writing processes accompanied with the erasing, writing, and reading operations (in the direct overwrite corresponding type medium which doesn't need the erasing operation, the test writing process for writing and reading) when the upper command is received are divided into a plurality of processing stages and are sequentially executed. Even when the apparatus temperature rapidly changes and the optimum power remarkably deviates from the default power which has initially been set and it takes a long time up to the end of the test writing operation to find the optimum power, since the processes are distributed and executed, a time-out for the upper command doesn't occur and the recording and reproducing operations can be executed as much as possible even when the power is deviated from the optimum power, so that the apparatus performance is improved.
The division test writing processing unit comprises a division executing unit and a division control unit. The division executing unit divides the test writing process into a plurality of processes and executes. When receiving the upper command, the division control unit discriminates about the necessity of the test writing. When it is determined that the test writing is needed, the division control unit skips to the head of the unexecuted processes in the division executing unit and allows the dividing process of the test writing operation to be executed for a predetermined time. Each time one of the division executing processes is finished, the division control unit preserves the processed number and a processing result. When the elapsed time from the start of the dividing process is shorter than a predetermined time, the processing routine advances to the next dividing process. When a predetermined time elapses, the division control unit interrupts the processes and waits for a next upper command. When the elapsed time from the preceding dividing process by the division executing unit to the present dividing process is longer than a predetermined time, the division control unit cancels the processed numbers and processing results of up to the preceding time and again executes the dividing processes from the beginning. When the interrupting time of the dividing process becomes too long, there is a case where the optimum power fluctuates due to the temperature change or the like during the interrupting time. In this case, a more accurate optimum power is found by again executing the processes from the beginning.
For example, the division executing unit is constructed by:
a first division executing unit for setting a predetermined initial light emitting power (default value) at the first time and for setting a light emitting power obtained by changing the initial light emitting power by every predetermined value at the next and subsequent times;
a second division executing unit for erasing a test area of a medium by the set light emitting power;
a third division executing unit for writing a predetermined test pattern into the erased test area;
a
Masaki Takashi
Yanagi Shigenori
Fujitsu Limited
Greer Burns & Crain Ltd.
Hindi Nabil
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