Abstract: A digital video signal record and playback device for recording on a recording medium a digital video signal coded by using a motion compensation prediction and an orthogonal transform and playing back data from the recording medium. In a data arrangement of a digital video signal, an I picture which can be independently represented in a picture is divided into n areas in the vertical direction, and the data is arranged from the front of one GOP in the unit of area by giving a priority to an area located at the center of the screen. A playback picture is outputted by playing back the I picture read from the recording medium in the unit of area unit. In the case where the whole I picture area cannot be read within a definite time, the area which cannot be read are interpolated by the use of the data of the preceding screen.

Abstract: An optical disc having both rewritable area and read-only area is disclosed. The rewritable area has a single spiral pattern of start track land at a leading edge, and a single spiral pattern of end track land at a trailing edge, whereby portions of the physical address area PID deviated approximately Pa/2 from the track of the rewritable area are being intruded into the start track land and the end track land.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: An optical disk according to the present invention has data recording tracks of lands and grooves. Each of the data recording tracks has a length corresponding to a revolution of the disk and includes a plurality of track sectors. The data recording tracks of lands and grooves are connected alternately to each other so as to form a continuous data recording spiral. Each of the track sectors has a preformatted identification signal part for representing sector address data and has a data recording part for recording data. The identification signal part has the first address data region and the second address region. The first address data region and the second address data region are shifted by the same predetermined distance from the center of a groove track oppositely in the radial direction of the disk.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: A disk cartridge has a case including a first planar portion and a second planar portion which are disposed opposite to each other with a given spacing therebetween, and a plurality of walls which join the first planar portion and the second planar portion together. The case contains an information carrying disk in a rotatable manner and has an opening formed in one of the walls through which the disk can be inserted or removed. The disk cartridge has a lid mounted on the case for opening or closing the opening. The lid is formed so that an outer surface of the lid is located inside an outer surface of the wall in which the opening is formed.

Abstract: A digital video signal record and playback device for recording on a recording medium a digital video signal coded by using a motion compensation prediction and an orthogonal transform and playing back data from the recording medium. In a data arrangement of a digital video signal, an I picture which can be independently represented in a picture is divided into n areas in the vertical direction, and the data is arranged from the front of one GOP in the unit of area by giving a priority to an area located at the center of the screen. A playback picture is outputted by playing back the I picture read from the recording medium in the unit of area unit. In the case where the whole I picture area cannot be read within a definite time, the area which cannot be read are interpolated by the use of the data of the preceding screen.

Abstract: A disk cartridge has a case including a first planar portion and a second planar portion which are disposed opposite to each other with a given spacing therebetween, and a plurality of walls which join the first planar portion and the second planar portion together. The case contains an information carrying disk in a rotatable manner and has an opening formed in one of the walls through which the disk can be inserted or removed. The disk cartridge has a lid mounted on the case for opening or closing the opening. The lid is formed so that an outer surface of the lid is located inside an outer surface of the wall in which the opening is formed.

Abstract: In an optical disk drive apparatus for recording data on and reproducing data from an optical disk using both of data recording tracks formed of grooves and lands, is divided into an integer number of sectors, and the address data area of each sector is shifted in the radial direction. When a first sector is scanned, a data from the address data area of the first sector is read as a first direct address data, and a data from the address data area of an adjacent sector is read as a second direct address data. A first modified address data of the first sector is produced by modifying the second direct address data with an inter-track address difference, and a correct address value of the first sector is produced using the first direct address data and the first modified address data.

Abstract: In an optical disk drive apparatus for recording data on and reproducing data from an optical disk using both of data recording tracks formed of grooves and lands, is divided into an integer number of sectors, and the address data area of each sector is shifted in the radial direction. When a first sector is scanned, a data from the address data area of the first sector is read as a first direct address data, and a data from the address data area of an adjacent sector is read as a second direct address data. A first modified address data of the first sector is produced by modifying the second direct address data with an inter-track address difference, and a correct address value of the first sector is produced using the first direct address data and the first modified address data.

Abstract: A turntable is a table mounted to a shaft (4) of a spindle motor and the turntable supports a laminated disc thereon and drives the disc in rotation. The laminated disc includes a lower disc and an upper disc stacked on the lower disc, and is supported on a disc-supporting surface. When the disc is loaded on the turntable, a fitting member fits into the center hole of the laminated disc for centering the laminated disc with respect to the shaft. The fitting member fits the center hole of the lower disc when the laminated disc is supported on said disc-supporting surface. The turntable may include a tapered member which guides the laminated disc to the disc-supporting surface. The laminated disc includes lower and upper discs each having an edge which defines the center hole. The corners of the edges are cut away along a circumference of the center hole. The upper and lower discs are placed together so that the cut-away corner directly face each other.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: An optical disk according to the present invention has data recording tracks of lands and grooves. Each of the data recording tracks has a length corresponding to a revolution of the disk and includes a plurality of track sectors. The data recording tracks of lands and grooves are connected alternately to form a continuous data recording spiral. Each of the track sectors has a preformatted identification signal part for representing sector address data and has a data recording part for recording data. The identification signal part has a first address data region and a second address region. The first address data region and the second address data region are shifted by the same predetermined distance in opposite directions from the center of a groove track in the radial direction of the disk. The first address data region is set to represent the address of a groove track sector, and the second address data region is set to represent the address of a land track sector adjacent to the groove track sector.

Abstract: In an optical disk drive apparatus for recording data on and reproducing data from an optical disk using both of data recording tracks formed of grooves and lands, is divided into an integer number of sectors, and the address data area of each sector is shifted in the radial direction. When a first sector is scanned, a data from the address data area of the first sector is read as a first direct address data, and a data from the address data area of an adjacent sector is read as a second direct address data. A first modified address data of the first sector is produced by modifying the second direct address data with an inter-track address difference, and a correct address value of the first sector is produced using the first direct address data and the first modified address data.

Abstract: A digital video signal record and playback device for recording on a recording medium a digital video signal coded by using a motion compensation prediction and an orthogonal transform and playing back data from the recording medium. In a data arrangement of a digital video signal, an I picture which can be independently represented in a picture is divided into n areas in the vertical direction, and the data is arranged from the front of one GOP in the unit of area by giving a priority to an area located at the center of the screen. A playback picture is outputted by playing back the I picture read from the recording medium in the unit of area unit. In the case where the whole I picture area cannot be read within a definite time, the area which cannot be read are interpolated by the use of the data of the preceding screen.

Abstract: An audio signal is recorded in a semiconductor memory in a plurality of hierarchical levels, with the lowest level being adequate for reproduction with a certain reduced degree of fidelity. Successively higher hierarchial levels provide successively greater fidelity when reproduced. When the memory has been determined to have reached maximum capacity, recording continues by overwriting the highest hierarchical level of data currently stored in the memory with lower hierarchical levels of new data. A code is recorded in the memory, indicating the number of hierarchical levels recorded therein, for subsequent reproduction. The audio signal can furthermore be recorded in variable-length frames and reproduced at high speed by reading every N-th frame, N being a positive integer, or by reading only frames having at least a certain minimum length.

Abstract: In an optical disk drive apparatus for recording data on and reproducing data from an optical disk using both of data recording tracks formed of grooves and lands, is divided into an integer number of sectors, and the address data area of each sector is shifted in the radial direction. When a first sector is scanned, a data from the address data area of the first sector is read as a first direct address data, and a data from the address data area of an adjacent sector is read as a second direct address data. A first modified address data of the first sector is produced by modifying the second direct address data with an inter-track address difference, and a correct address value of the first, sector is produced using the first direct address data and the first modified address data.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: A turntable is a table mounted to a shaft (4) of a spindle motor and the turntable supports a laminated disc thereon and drives the disc in rotation. The laminated disc includes a lower disc and an upper disc stacked on the lower disc, and is supported on a disc-supporting surface. When the disc is loaded on the turntable, a fitting member fits into the center hole of the laminated disc for centering the laminated disc with respect to the shaft. The fitting member fits the center hole of the lower disc when the laminated disc is supported on said disc-supporting surface. The turntable may include a tapered member which guides the laminated disc to the disc-supporting surface. The laminated disc includes lower and upper discs each having an edge which defines the center hole. The corners of the edges are cut away along a circumference of the center hole. The upper and lower discs are placed together so that the cut-away corner directly face each other.