Abstract: A rewritable optical recording medium includes a segmented groove area in which the groove track is segmented along a rotating direction of the recording medium by groove non-forming portions to form a plurality of groove portions; and a continuous groove area in which a continuous groove is formed, the continuous groove having a groove width smaller than a groove width in the segmented groove area.

Abstract: A rewritable optical recording medium includes a segmented groove area in which the groove track is segmented along a rotating direction of the recording medium by groove non-forming portions to form a plurality of groove portions; and a continuous groove area in which a continuous groove is formed, the continuous groove having a groove width smaller than a groove width in the segmented groove area.

Abstract: A recording medium includes pairs of groove tracks and land tracks having periodically formed bent portion provided side by side on a substrate, a plurality of land prepits previously formed on the land tracks and carrying information about the groove tracks, and a recording layer formed on at least the groove tracks and the land tracks. The land prepits have a radius of mean curvature smaller than a radius of mean curvature of sides of the groove tracks in land-prepit absent regions of the land prepits and are defined by curved surfaces continuously extending from the sides of the groove tracks. Those sides of the groove tracks which face the continuous curved surfaces of the land prepits are curved surfaces that stricture the groove tracks. The depth of the land prepit is larger than that of the groove track.

Abstract: A rewritable optical recording medium includes a segmented groove area in which the groove track is segmented along a rotating direction of the recording medium by groove non-forming portions to form a plurality of groove portions; and a continuous groove area in which a continuous groove is formed, the continuous groove having a groove width smaller than a groove width in the segmented groove area.

Abstract: The present invention provides an optical recording medium, in which levels of wobble signals extracted from a recording area formed snakily, a reproduction exclusive area and an impossible area are maintained constant. On DVD-RW, groove tracks are snakily formed on a groove section on which recording information is recorded, and pit strings where a plurality of phase pits wave are arranged on the impossible area and the reproduction exclusive area which prevent illegal copying. On the respective areas, pit depths (groove depths), duty of the pit strings and wobbling amplitudes are set according to predetermined conditions so that the output levels of the wobble signals extracted based on the wobbling amplitudes can be maintained constant on the respective areas. As a result, synchronous control can be made accurately at the time of recording and reproduction on/from the DVD-RW.

Abstract: It is determined that an optical disc reproduced in a reproducing system has version-up data. In response to the determination, it is determined the necessity of updating firmware stored in the reproducing system. In response to the determination of existence of the version-up data and the necessity of updating, the firmware stored in the reproducing system is changed with the version-up data recorded on the optical disc.

Abstract: A rotation number of a motor adapted to rotate a record medium having a disc shape with respect to a pickup is controlled.

Abstract: An apparatus for reproducing information recorded on an optical recording medium comprising a substrate on which a series of pits which have depth of 2.sup.N (N is an integer equal to or more than 2) steps are formed and a reflecting layer formed on the substrate to cover the series of pits. The apparatus includes a light source, a light detecting means for detecting light reflected from the optical recording medium and obtaining a read-out signal, and a level detecting circuit for detecting multiple levels corresponding to the level of the read-out signal by comparing the read-out signal with multiple level detecting windows. The width of the window is set wide at a lower signal level and the width of the window is set narrow at a higher signal level.

Abstract: A disc-shaped record medium provided with an information recording area including tracks for recording information therein, which information recording area is divided into a plurality of circular recording areas in the radial direction thereof. Each of the circular recording areas includes at least a first block wherein individual track pitches are gradually reduced in accordance with the radial distance from the center portion of the record medium. Also, a second block may be provided following the first block, in which track pitches are gradually increased in proportion to the radial distance from the center portion of the record medium. With the disc-shaped record medium constructed as such, not only can the recording capacity thereof as a whole be increased, but smooth shifting of the head for an information recording or reproducing operation is also obtained.