Abstract: An optical disc that has a recognition mark area behind a recorded area and in which the last data in the recorded area is stably accessed, the recognition mark area can be accessed without bringing about an abnormal state, and the first data in a succeeding recorded area, if it exists, is stably accessed. An unrecorded area (5) is provided outside the recorded area (4) of the optical disc (1). A mark area (6) is provided between the recorded area (4) and unrecorded area (5). A recognition mark area (6d) is provided in the mark area (6) in order to recognize the boundary between the recorded area (4) and the unrecorded area (5). In the mark area (6), first and second buffer areas (6b and 6c) are provided respectively in front of and behind the recognition mark area (6d).

Abstract: An analysis apparatus capable of normally creating image data and an analysis disc used for this. Instead of using a signal which has been read in time series by pickup following a track so as to create an image by utilizing address information engraved on an optical disc, a mark (110) is recorded over the radius direction (A) of a read area (109) of the analysis disc (108) where an analysis object (B) is arranged, at least at a preceding position or a following position of the read area (109) in the rotation direction (C), so that video processing aligned according to this mark is executed, thereby executing video acquisition or a shape count with a high accuracy.

Abstract: At spin-up of an optical disk 3, gain adjustment and offset adjustment are performed on a servo error signal to obtain a first gain adjustment value and a first offset adjustment value. Based on the first gain adjustment value, a CPU 11 obtains a second gain adjustment value and a second offset adjustment value at data writing on the optical disk 3, and stores them in storage 7. When the reading state of the optical disk 3 shifts to the writing operation, the CPU 11 controls a laser power switching circuit 12 to change the output from an optical pickup 1 and, simultaneously, reads the second offset adjustment value and gain adjustment value stored in the storage 7 and sets them in an offset adjustment unit 5 and a gain adjustment unit 8, respectively.

Abstract: The present invention relates to loop gain adjustment of a focus/tracking servo in an optical disk apparatus, and provides an optical disk apparatus which can make the loop gain adjustment converge normally even in an optical disk in which prerecorded areas and recorded areas are mixed, and further which always has a stable servo system even when a gain is significantly varied due to changes in the disk state. When an inserted optical disk is determined to be a recordable optical disk by an optical disk type determination means 22, an optical pickup 1 is made seek a previously set area, thereby performing the loop gain adjustment. Further, when a gain is varied during the operation, a gain adjusting means 10 changes over a gain adjustment value.

Abstract: An optical disc that has a recognition mark area behind a recorded area and in which the last data in the recorded area is stably accessed, the recognition mark area can be accessed without bringing about an abnormal state, and the first data in a succeeding recorded area, if it exists, is stably accessed. An unrecorded area (5) is provided outside the recorded area (4) of the optical disc (1). A mark area (6) is provided between the recorded area (4) and unrecorded area (5). A recognition mark area (6d) is provided in the mark area (6) in order to recognize the boundary between the recorded area (4) and the unrecorded area (5). In the mark area (6), first and second buffer areas (6b and 6c) are provided respectively in front of and behind the recognition mark area (6d).

Abstract: An optical disc that has a recognition mark area behind a recorded area and in which the last data in the recorded area is stably accessed, the recognition mark area can be accessed without bringing about an abnormal state, and the first data in a succeeding recorded area, if it exists, is stably accessed. An unrecorded area (5) is provided outside the recorded area (4) of the optical disc (1). A mark area (6) is provided between the recorded area (4) and unrecorded area (5). A recognition mark area (6d) is provided in the mark area (6) in order to recognize the boundary between the recorded area (4) and the unrecorded area (5). In the mark area (6), first and second buffer areas (6b and 6c) are provided respectively in front of and behind the recognition mark area (6d).

Abstract: The present invention relates to an optical disk apparatus which performs information recording or reproduction into/from an optical disk, and provides an optical disk apparatus which makes the amount of optical pickup movement performed before adjustment of a track error signal suited and enables reduction of a start-up time. When a track error signal is subjected to adjustment, it is previously detected in a signal amplitude detecting circuit 17 whether an optical pickup 1 is located in an area where a required track on an optical disk medium 2 exists or not, and a micro processing unit 6 executes the procedure which uses only the necessary but minimum moving time, even when the optical pickup is required to be moved.

Abstract: The present invention relates to an optical disk apparatus which performs information recording or reproduction into/from an optical disk, and provides an optical disk apparatus which makes the amount of optical pickup movement performed before adjustment of a track error signal suited and enables reduction of a start-up time.

Abstract: At spin-up of an optical disk 3, gain adjustment and offset adjustment are performed on a servo error signal to obtain a first gain adjustment value and a first offset adjustment value. Based on the first gain adjustment value, a CPU 11 obtains a second gain adjustment value and a second offset adjustment value at data writing on the optical disk 3, and stores them in a storage means 7. When the reading state of the optical disk 3 shifts to the writing operation, the CPU 11 controls a laser power switching circuit 12 to change the output from an optical pickup 1 and, simultaneously, reads the second offset adjustment value and gain adjustment value stored in the storage means 7 and sets them in an offset adjustment unit 5 and a gain adjustment unit 8, respectively.

Abstract: The present invention relates to loop gain adjustment of a focus/tracking servo in an optical disk apparatus, and provides an optical disk apparatus which can make the loop gain adjustment converge normally even in an optical disk in which prerecorded areas and recorded areas are mixed, and further which always has a stable servo system even when a gain is significantly varied due to changes in the disk state.