Abstract: A recording and/or reproducing apparatus is disclosed in which informational signals are recorded and/or reproduced by irradiating an optical disc 202 with a light beam from an optical pick-up device 1 through an recording and/or reproducing opening 205 which is formed in a disc cartridge 202 which rotatably houses an optical disc 203. The optical pick-up device 1 which is used for the recording and/or reproducing apparatus comprises a light source and an objective lens 5 for converging the light beam from the light source upon the signal recording area of the optical disc 203. When recording and/or reproducing of informational signal on and/or from the optical disc 203 is performed by the optical pick-up device 1, only the objective lens 5 is moved into the disc cartridge 202 via the recording and/or reproducing opening 205 formed on the disc cartridge 202 to shorten the distance between the objective lens 5 of the optical pick-up device 1 and the disc 203.

Abstract: A disc-shaped recording medium and a recording/reproducing apparatus employing the disc-shaped recording medium as a recording medium, are disclosed. The recording medium has a diameter of not more than 80 mm, and a recording track is formed on the recording medium with a track pitch of approximately 1.6 .mu.m. Information in excess of 130 Mbytes is recorded in a data compressed state on the recording track and the recording medium is rotationally driven at a constant linear velocity for recording and optically reproducing the information.

Abstract: A disc-shaped recording medium for storing compressed audio data which have been recorded thereon by an optical recording apparatus. The inner diameter of a data recording region of the disc-shaped recording medium is in the range from 28 mm to 50 mm. The outer diameter of the data recording region is in the range from 58 mm to 62 mm for an inner diameter of 28 mm, and is in the range from 71 mm to 73 mm for an inner diameter of 50 mm. The disc-shaped recording medium may be used with a small-sized portable disc recording and reproducing apparatus, and can record compressed audio data for playback with a playback time substantially as long as that of a standard compact disc having 12 cm diameter.

Abstract: There is provided a disc recording apparatus for recording digital data by an optical unit in such a manner that time compressed digital data are arranged into a plurality of clusters at an interval of a predetermined number of sectors, a cluster-linking sector having a length longer than an interleaving length is provided at each linking part of each cluster, and the digital data are subsequently interleaved and recorded on a disc-shaped recording medium so that interleaving at the time of data recording on the cluster-by-cluster basis is within the range of the cluster-linking sector.

Abstract: A spread spectrum signal receiving apparatus comprising: a radio frequency processing circuit for converting a spread spectrum signal into an intermediate frequency signal; a binary encoder for encoding the intermediate frequency signal; a pseudo-random noise code generator; a code driver for controlling the phase and the chip speed of the output of the code generator; a first multiplier for multiplying the binary signal by the output of the code generator; a numerical controlled oscillator for outputting first and second carrier signals; second and third multipliers for multiplying the output signal of the first multiplier respectively by the first and second carrier signals; first and second low-pass filters supplied with the output signals of the second and third multipliers respectively; and a microcomputer having functions to produce signals for controlling the numerical controlled oscillator, and functions to produce signals for controlling the code driver.

Abstract: During recording the inputted data are sequentially written into a memory at one transfer rate and are read out at a second, higher transfer rate for recording on a record medium. The reading of the memory is such that data in a preset first amount are successively read from the memory to always ensure a write space in the memory which has a capacity which is higher than a predetermined second amount when the amount of the inputted data stored in the memory exceeds the first amount. During playback, the recorded data are reproduced at a second transfer rate, which is higher than a first transfer rate required for outputting the reproduced data, and are written in the memory. The thus written data are successively read out of the memory as reproduced output data at the first transfer rate.

Abstract: The present invention is concerned with an optical disk reproducing apparatus for reproducing digital data from an optical disk, such as an audio compact disk and, above all, with such apparatus in which a continuous playback output may be produced even when track jump should occur due to vibrations or the like. With the optical disk reproducing apparatus according to the present invention, digital data detected from an optical disk are sequentially written in a RAM for subsequent reading so that data stored in the RAM continue to be read even on the occurrence of the track jump to provide a continuous playback output. On the other hand, the optical disk is reproduced at an increased speed for a predetermined time period after the light spot irradiating the optical disk resets to its original position from track jump to replenish digital data to the RAM.

Abstract: A disk recording/reproducing apparatus and a disk recording/reproducing method wherein a recording disk (1) having an absolute address is provided with a program region (6) and a read-in region (7), data such as play data are recorded on the program region (6), the data are recorded on the read-in region (7) using, as catalog data, a start address data of a data unit region where the data have been recorded and a finish address data, and the data on the program region (6) are reproduced from the catalog data in the read-in region (7). An erase inhibit flag is set to the catalog data for each of the data units, whereby the erase inhibit and the erase enable are designated by the erase inhibit flag for each of the data units for the data that are recorded on the program region (6).

Abstract: An optomagnetic disk recording and reproducing apparatus includes an optomagnetic disk having a vertical magnetic film capable of recording and reproducing an information signal, a recording and reproducing head unit for recording an information signal in the optomagnetic disk and reproducing an information signal recorded in the optomagnetic disk, a spindle motor for rotationally driving the optomagnetic disk, and means for controlling the spindle motor such that a rotational speed of the optomagnetic disk upon reproducing of an information signal recorded in the optomagnetic disk performed by the recording and reproducing head unit is set higher than the rotational speed of the optomagnetic disk upon recording of an information signal in the optomagnetic disk performed by the recording and reproducing head unit.

Abstract: A disk recording apparatus for recording data such as information concerning a musical performance on a recording disk (1) to which absolute addresses have been imparted in advance. Vibration during the recording operation and unexpected track jumping due to defects in the recording disk are detected relying upon the discontinuity of absolute addresses reproduced from the recording disk (1). In case track jumping has taken place, the laser power of the optical head (12) is dropped to the reproduction level and the track jump control is actuated to access a desired track. The recording operation is then resumed for the track.

Abstract: An objective lens (3) of an optical pick up head (10) is moved in a direction of the optical axis, and a signal level of the output detected by the optical pick up head (10) before and after a focussed state is compared with predetermined reference levels (Vref.sub.1) and (Vref.sub.2) level comparators (32) and (33), In order to discriminate the reproduction-only disk from the recording disk by utilizing a difference in the reflection factor on the recording surface on the optical disk (20). Operation of the optical disk recording/reproducing apparatus is automatically switched over depending upon the kind of the optical disk.

Abstract: A method and apparatus for preventing copying of an optical disk. A software program and the basic data necessary for executing the program, as well as an erasing program are nonrewritably recorded in advance on a predetermined region of the disk. The erasing program attempts to erase the non-rewritable portion, which has no effect on the original disk, but will erase that portion of a disk which is copied. Thus, if the software program and the basic data for executing the program are copied without authorization, the copy disk is prevented from being used.

Abstract: Apparatus and method of recording and reproducing data using a disk to record musical performance data. Data related to the music and start times for each piece of music are recorded onto a table of contents section of the disk and the operation is controlled according to this data. Therefore, wasteful reproduction operation is avoided when there exists non-recorded areas between pieces of music or when a piece of music shorter than the initial piece of music is recorded overlapped thereon, enabling the music to be favorably reproduced. In carrying out the (sound) recording operation, furthermore, the non-recorded areas can quickly be found.

Abstract: A tracking servo signal is generated for use in an optical disc pick-up system, being particularly advantageous for use when the depth of the pits is greater or less than one-fourth the wavelength of the light beam used to read the disc, in which case diffraction patterns formed by reflected light beams are not symmetric on a photo-detector and typically result in DC-shifted tracking error signals. A first tracking error signal is generated from selected output signals of a number of light-receiving areas of the photo-detector and a second tracking error signal is generated by combining output signals from these light-receiving areas in a pattern different than that used in generating the first tracking error signal. These two tracking error signals are combined so that the resultant signal forms a tracking servo signal that has substantially no DC component.

Abstract: Novel triorganostannyl derivatives of deoxynucleosides or deoxynucleotides of the general formula: ##STR1## wherein R.sup.1 is an alkyl or aryl group, R.sup.2 is a protecting group, R.sup.3 is a protecting group, B is a base residue which may have a protecting group, and n is zero or a positive integer and their amine salts are provided. They are prepared by reacting a deoxynucleoside or deoxynucleotide with either a triorganotin amide or a triorgano(alkoxy)stannane and may be useful as intermediates for the preparation of oligodeoxynecleotides.

Abstract: A disk recording device records blocks of data such as musical information on a recordable disk where absolute addresses have been previously recorded. Address data indicating the starting and ending address of each block is recorded in a lead-in section, and recordable areas of the program area, such as unrecorded parts or unnecessarily recorded parts, are detected on the basis of the address data of each block. The respective lengths of the recordable areas are indicated. Hence the user can easily identify unrecorded or unnecessarily recorded areas that are long enough for further recording.

Abstract: An optical disk recording/reproducing device that records and reproduces digital audio data by executing an interleave processing for error correction is disclosed. According to the invention, when new musical information is recorded successively after previously recorded musical information, recording is started by digitally adding zero data for a prescribed period. Similarly, upon stopping recording of the musical information, zero data are digitally added for a prescribed period so as to end recording. The present invention is made to produce no abnormal sounds in a boundary section of one musical information in its reproduction state and the other musical information that comes immediately before or after it.

Abstract: Novel phosphorsulfide derivatives of deoxynucleosides or deoxynucleotides are provided, which have the general formula: ##STR1## wherein R.sup.1 is a hydroxy-protecting group; R.sup.2 is a phosphate-protecting group; R.sup.3 is an aryl group; B.sub.1 and B.sub.2 may be the same or different and each are a base residue which may have a protecting group; and n is zero or a positive integer, provided that if n is 2 or larger, the respective R.sup.2 may be the same or different. They are prepared by reacting a deoxynucleoside or deoxynucleotide with a 1,2,4-triazolylphosphine compound and are useful as intermediates for the preparation of oligodeoxy-nucleotides.

Abstract: A data signal reproducing apparatus reproduces digital data from a recording medium on which a digital data signal modulated in accordance with the run length limited code modulation is recorded together with a synchronous signal. The apparatus is improved so that erroneous detection of a false synchronous signal is avoided when there is a defective part on the recording surface of the recording medium. In the apparatus, a reproduced signal of rectangular waveform from waveform shaping means (9) is prevented from being supplied to reproduced signal processing means (13) when the amplitude of a head output signal detected by amplitude detecting means (14 to 17) is less than a predetermined value, thereby avoiding erroneous detection of the false synchronous signal. The apparatus is suitable for being constituted to be a player for a digital audio disc.

Abstract: A tracking control arrangement for use in an optical disc player comprises a photodetecting assembly including a plurality of photodetecting elements each provided for receiving a light beam caused to impinge on an optical disc to read an information signal recorded in a record track thereon and reflected thereat and for producing an output in response to the received light beam, an operational circuit operative to generate from the outputs of the photodetecting elements a reproduced information signal and a resultant signal varying in phase relative to the reproduced information signal in response to the direction of deviation of a beam spot formed on the optical disc by the light beam from the center of the record track and varying in amplitude in response to the amount of the deviation, an error signal generating circuit operative to generate a tracking error signal in the form of voltage held by voltage holding means on the basis of both the reproduced information signal and the resultant signal obtained