Abstract: A recording medium comprises pairs of groove tracks and land tracks provided side by side while being bent periodically, 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.

Abstract: An information recording apparatus is provided with: a recording device for recording information onto an information recording medium; a detrack detecting device for detecting occurrence of detrack during the recording of the information; and a controlling device for controlling said recording device to return to a location where the detrack has occurred and restart the recording if the occurrence of the detrack is detected

Abstract: Based on a recording signal, a recording pulse signal, which includes a top pulse located at a front end portion and having a first magnitude, a last pulse located at a back end portion and having the first magnitude, and an intermediate bias portion located between the top pulse and the last pulse and having a second magnitude, is generated. Based on the recording pulse signal, a light source is controlled, and a laser pulse is irradiated on a recording medium. Recording marks corresponding to the recording signal are formed on the recording medium. In generating the recording pulse signal, when the recording medium is rotationally driven, a position of the top pulse is shifted ahead of a position of the top pulse when the recording medium is rotationally driven at the first rotation speed, when the recording medium is rotationally driven at the second control speed.

Abstract: An information recording apparatus for recording information onto an information recording medium having a plurality of recording layers, by irradiating the information recording medium with laser light for recording, the information recording apparatus including: a setting device for setting a preferable irradiation condition of the laser light which is preferable to one recording layer in which the information is scheduled to be recorded, out of the plurality of recording layers, for each recording state of another recording layer out of the plurality of recording layers; and an irradiating device for irradiating the one recording layer with the laser light in the set preferable irradiation condition.

Abstract: The information recording apparatus irradiates a laser beam on a recording medium such as an optical disk and forms a recording mark corresponding to a recording signal to record information. A recording pulse signal includes a mark period irradiating the laser beam for forming the recording mark and a space period in which the recording mark is not formed. The mark period has a top pulse period and an intermediate bias period following the top pulse period. The mark period constituted by the top pulse period and the intermediate bias period does not have a continuous part of a plurality of pulses having a small pulse width unlike a pulse train, so that the correct recording mark can be stably formed on the recording medium without an inadequate deformation of a recording pulse shape, even in the case of a high speed recording.

Abstract: By the control information recording method, control information to control at least one of recording and reproducing operations of record information on an information record medium is recorded onto a guide track of the information record medium. The control information recording method is provided with the steps of: generating a control information timing signal one after another at an interval corresponding to a length of a control information unit equal to an N (N: predetermined integer not less than 2) multiple of a length of a record information unit of the record information; and recording the control information onto the guide track of the information record medium, on the basis of a timing corresponding to the control information timing signal.

Abstract: A power threshold value (12) is set to be compared with a correlation power value detected by a correlator (2) and a power conversion section (4). As a result of comparison by a comparator (13), only the correlation power values that exceed the threshold value (12) are stored in a power value memory (14), and unnecessary correlation values at noise levels are not stored in the memory (14) so that the number of power values stored can be decreased. With this construction, the necessary memory capacity can be decreased, and the process of searching for the maximum value from the correlation power values stored in the memory (14) can be performed at a higher speed.

Abstract: In a recording strategy suitable for high-speed recording, a laser driving signal includes a top pulse having a pulse width corresponding to a recording mark length and multi-pulses having a period 3-times larger than a base clock period of a recording mark. The top pulse is has the first identical-shape top pulses when the recording mark length is 3 nT (“n” is a natural number), the second identical-shape top pulses when the recording mark length is (3 n+1)T, and the third identical-shape top pulses when the recording mark length is (3n+2)T.

Abstract: An error detector at a receiver comprises a feedback shift register. A shift direction in the feedback shift register is opposite to a shift direction at a transmitter in generating a transmission bit string by using a specified generator polynomial. A reception bit string is inputted to the feedback shift register in reverse order to the transmission bit string was generated at the transmitter so that errors in the reception bit string is detected by obtaining the remainder. Another error detector at a receiver comprises first and second feedback shift registers. Respective shift directions in the first and second feedback shift registers are the same as and opposite to a shift direction at a transmitter in generating a transmission bit string.

Abstract: An information recording medium is provided which can eliminate the influence of noise such as crosstalk to a wobble signal. A track is subjected to wobbling based on a wobble signal in which at least one portion of recording information is randomized.

Abstract: When changing the number of oversamples is performed, tap factors selected by selectors, which respectively correspond to holding parts in a shift register, are changed back to a predetermined number of tap factors used before the changing of the number of oversamples, in which every time input data is accepted, the changes of the tap factors are performed in sequence, starting from the selector corresponding to the holding part at the input side. This allows the individual selectors to select proper tap factors according to the input data after the changing of the number of oversamples. As a result, the continuity of the output data is maintained even before and after the number of oversamples is changed.

Abstract: In a DVD-R on which information is to be recorded by an information recording apparatus, prior to the recording of the information therein, there are recorded in advance at least identification information for identifying the information recording apparatus for recording the information onto the DVD-R, and recording parameter information containing optimization information for optimizing a recording state in the record processing executed by the information recording apparatus specified by the identification information. Furthermore, the information recording apparatus reads the recording parameter information at the execution of record processing to use it for the record processing.

Abstract: Based on a recording signal, a recording pulse signal, which includes a top pulse located at a front end portion and having a first magnitude, a last pulse located at a back end portion and having the first magnitude, and an intermediate bias portion located between the top pulse and the last pulse and having a second magnitude, is generated. Based on the recording pulse signal, a light source is controlled, and a laser pulse is irradiated on a recording medium. Recording marks corresponding to the recording signal are formed on the recording medium. In generating the recording pulse signal, when the recording medium is rotationally driven, a position of the top pulse is shifted ahead of a position of the top pulse when the recording medium is rotationally driven at the first rotation speed, when the recording medium is rotationally driven at the second control speed.

Abstract: A semiconductor having an internal memory of the present invention comprises a first memory copying and holding a data held in a storage device; a second memory holding a check code of the data held in the first memory, and being constantly supplied with a source voltage not lower than a data-holding-guarantee voltage; a data check unit detecting error in the data held by the first memory based on the check code; and reloading units copying only the data corresponded to the block having a data error detected therein by the data check unit, from the storage device to the first memory, to make it possible to detect any error in the data held in the first memory to thereby guarantee the data, and to lower the source voltage to be supplied to the first memory.

Abstract: A receiving unit for receiving a CDMA system signal having a plurality of multipath components is intended to reduce the size. A receiving section receives a CDMA system signal. A storage section stores the signal received by the receiving section. A demodulation section demodulates each of multipath components included in the received signal stored in the storage section with a despreading code. A control section controls for demodulating a plurality of the multipath components by causing the demodulation section to perform a time division multiplex process. A Rake combining section performs the maximal ratio combining of output from the demodulation section to generate a demodulated signal.

Abstract: An error detector at a receiver comprises a feedback shift register. A shift direction in the feedback shift register is opposite to a shift direction at a transmitter in generating a transmission bit string by using a specified generator polynomial. A reception bit string is inputted to the feedback shift register in reverse order to the transmission bit string was generated at the transmitter so that errors in the reception bit string is detected by obtaining the remainder. Another error detector at a receiver comprises first and second feedback shift registers. Respective shift directions in the first and second feedback shift registers are the same as and opposite to a shift direction at a transmitter in generating a transmission bit string.

Abstract: The FIR filter separately receives input data consisting of transmitting information and composed of bit strings, and additional data which is added in order to transmit the input data. The input data is operated with the additional data. A difference between the additional data corresponding to previous data (for instance, most recent data) among the input data and the additional data corresponding present data is obtained, and the difference and the previous data are operated. Then, the operation results are added and the resultant is outputted as a filter response. The input data and the additional data are separately received to be operated so that the circuit scale of the filter is reduced. Therefore, a chip of the semiconductor integrated circuit can be downsized and thereby cost reduction in the communication system can be realized.

Abstract: An information recording medium is provided with a wobbled track, wherein at least a part of the track is subjected to wobbling based on a wobble signal in which at least a part of recording information is randomized. Each track is wobbled at a randomized frequency, so that a frequency of a wobbling signal obtained from the wobbled track is randomized. As a result, the influence of crosstalk between adjacent track is reduced.

Abstract: A semiconductor device in which consumption of power attendant on a leakage current in a block where the power is turned on and off intermittently is reduced. In the semiconductor device according to the present invention, an error check necessity judgment circuit judges on notification from an error check necessity notification circuit located in a block where the power is not disconnected whether an error check must be made, and an error check execution circuit makes an error check on data loaded from an external memory at the time of a boot in accordance with the judgment of the error check necessity judgment circuit. An error check cannot completely be omitted. Therefore, to ensure the reliability of a system, an error check is forcedly made once whenever a boot is performed times set by an error check interval setting circuit. This shortens intermittent operation time by time taken to make an error check, resulting in a reduction in consumption of power attendant on a useless leakage current.

Abstract: When a bias power level of a recording pulse waveform is varied entirely or partially, a shape of the recording pulse wave form is varied according to the variation. For example, when the bias power level is increased, a width or an edge position of a top pulse or a multi-pulse of the recording pulse waveform is varied correspondingly. Thereby, a total heat quantity of a recording laser light is not increased, and a preferable recording characteristic is maintained.