Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
1999-05-26
2001-07-24
Huber, Paul W. (Department: 2651)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S032010
Reexamination Certificate
active
06266308
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an optical disc drive for recording and playing back an optical disc and a method of detecting an end portion of recorded data recorded in an optical disc loaded in the optical disc drive.
2. Description of the Prior Art
There are known optical disc drives for recording and playing back (reproducing) a recordable type optical disc such as a CD-R (CD-Recordable)or CD-RW (CD-Rewritable) or the like.
In such an optical disc drive, there is a case that recording operation is stopped or interrupted during carrying out the operation, because servo control such as a tracking servo control comes to an disengaging or disenabling state due to vibration or the like. In such a case, in order to specify the end portion of the recorded data (a part of data which has been recorded), detection operation is carried out for seeking out the end portion for the recorded data.
However, in the conventional optical disc drives, they perform many unnecessary processes for detecting the end portion of the recorded data, so that it takes a relatively long time for detecting the end portion of the recorded data.
SUMMARY OF THE INVENTION
In view of the problem in the prior art described above, the object of the present invention is to provide an optical disc and a method of detecting an end portion of recorded data recorded in an optical disc loaded in the optical disc drive which can detect an end portion of recorded data recorded in an optical disc in a short time.
In order to achieve the object, the present invention is directed to an optical disc drive for recording and playing back an optical disc having a plurality of tracks. The disc drive comprises an optical disc driving mechanism for rotating an optical disc; an optical pick-up for recording and playing back data to and from the optical disc; signal processing means at least for processing signals read out from the optical disc through the optical pick-up; and control means for controlling at least the optical disc driving mechanism, the optical pick-up and the signal processing means, and means for detecting an end portion of recorded data in the optical disc. In detecting the end portion, a detection starting position and a detection ending position are set in the optical disc and the number of tracks between the detection starting position and the detection ending position is divided into more than three divided portions defined by dividing points. Then, the detecting means detects presence or absence of the recorded data in each of the dividing points by moving the optical pick-up from the detecting starting point and then determines that the end portion of the recorded data lies in a divided portion specified between the dividing point at which presence of the data is detected and the adjacent other dividing point at which absence of the data is detected.
According to the optical disc drive as described above, it is possible to detect the end portion of the recorded data recorded in the optical disc in a short time.
In the present invention, it is preferred that the optical pick-up is moved in a stepwise manner without acquiring time information from the optical disc. Specifically, the optical pick-up is moved from one dividing point to adjacent dividing point by means of a track jump operation without acquiring time information from the optical disc on or before the absence of the data is detected.
According to the optical disc drive as described above, it does not need a time for acquiring the time information such as ATIP information which is previously recorded in the optical disc when the optical pick-up is moved on each of the dividing points and a time for processing the time information. This also makes it possible to shorten the time required for the detection of the end portion of the recorded data.
In the present invention, it is preferred that the detecting means is constructed to repeatedly continue the detection of the presence or absence of the recorded data for thus obtained specified divided portion until the interval of a subsequently obtained divided portion becomes less than a predetermined value, in which the dividing point at which the presence of the data is detected is set to be one of a detection starting position and a detection ending position and the adjacent other dividing point is set to be the other position, and in the subsequent process vice versa.
Further, it is also preferred that the detecting means is constructed to detect the presence and absence of the data continuously in the specified divided portion after the interval of the specified divided portion has become smaller than the predetermined value, thereby specifying the end portion of the recorded data.
Furthermore, in the present invention, the optical disc drive can further comprise means for counting the number of tracks on which the optical pick-up has passed, in which the detecting means is constructed to move the optical pick-up to the target track while grasping the position of the optical pick-up relative to the optical disc based on the counted value of the counting means.
Moreover, in the present invention, it is preferred that the number of the divided portions is 8 to 10.
Another aspect of the present invention is directed to a method of detecting an end portion of recorded data recorded in an optical disc loaded in an optical disc drive. The method comprises the steps of: (a) setting a detection starting position and a detection ending position on the optical disc; (b) dividing the number of tracks between the detection starting position and the detection ending position into more than three divided portions defined by dividing points; (c) detecting presence or absence of the recorded data at each of the dividing points sequentially from the detection starting point; and (d) determining that the end portion of the recorded data lies in a divided portion specified between the dividing point at which presence of the data is detected and the adjacent other dividing point at which absence of the data is detected.
According to this method, it is also possible to detect the end portion of the recorded data recorded in the optical disc in a short time.
In this method, it is preferred that the optical disc drive is equipped with an optical pick-up for recording and playing back data, in which the detection of the presence or absence of the recorded data is carried out by moving the optical pick-up in a stepwise manner without acquiring time information recorded in the optical disc.
Further, it is also preferred that the steps (a) to (d) are repeatedly carried out for the specified divided portion and then a subsequently obtained divided portion until the interval of the divided portion becomes less than a predetermined value.
Furthermore, it is preferred that the method further comprises the step of detecting the presence and absence of the data continuously in the specified divided portion after the interval of the specified divided portion has become smaller than the predetermined value, thereby specifying the end portion of the recorded data.
In this method, it is preferred that the number of the divided portions is 8 to 10.
Other objects, structures and advantages of the present invention will be apparent when the following description of the preferred embodiment is considered taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5081616 (1992-01-01), Kitihara et al.
patent: 5559778 (1996-09-01), Inokuchi et al.
patent: 5706261 (1998-01-01), Udagawa
patent: 0552986A2 (1993-07-01), None
Huber Paul W.
Mitsumi Electric Co.
Patents +TMS
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