Abstract: A disk-shaped recording medium has a control record region in each recording region of successive recording tracks and which is divided into a first preformat region, a second preformat region and a focusing servo region arranged in succession in the direction along the respective track and respectively providing traverse data, tracking and clock data, and focusing servo data. An apparatus for reproducing data recorded in the tracks of such disk-shaped recording medium samples a playback output from an optical head scanning a track to detect focusing data from the focusing servo region and tracking data from the second preformat region and, in response thereto, applies focusing servo or tracking servo to the optical head. Further, traverse data is detected in the first preformat region to effect traverse counting of the recording tracks.

Abstract: A video signal reproducing apparatus comprising a head for reproducing video signals recorded in plural tracks accompanied with guard bands on a recording medium is disclosed, wherein the head is transferred from track to track so that the head is positioned substantially on the guard band in the blanking period of the video signals and that any noise produced during the track transfer is thus minimized.

Abstract: Method and apparatus for producing customized video recordings. The apparatus includes audio/video reproduction equipment for displaying prompt information and for providing a first audio signal synchronous with the prompt information. The apparatus further includes a device for providing a first video signal representative of background information, audio/video recording equipment for providing a second video signal and a second audio signal representative of a live performance performed synchronously with the display of the prompt information. A mixer is provided for combining the first and second audio and video signals, and creative modification are added whereupon the combined signals are recorded to form the customized video recording.

Abstract: An optical pick-up device for use in an optical disc information recording/reproducing apparatus is provided. In the present optical pick-up device, the functions of two or more separate optical elements provided in the prior art structure are combined or integrated in a single element to reduce the total number of separate optical elements provided in the device. In particular, use is made of a diffraction grating rather than lenses and/or lenses are formed as holo lenses. A diffraction grating and a holo lens may be formed substantially in the shape of flat plates, so that many optical components can be put together to define an integrated subassembly, which reduces the total number of discrete elements, facilitates manufacturing and eliminates the necessity of adjustments among optical elements once set.

Abstract: A laser-optical write and read process whereby a thermally alterable recording layer which contains liquid-crystalline compounds in homogeneous planar orientation and forms part of a multilayer, sheet-like recording material is written by means of a write laser beam with analogue or digital data in the form of thermally altered areas, whereafter the written data are read by means of a read laser beam, including: analyzing the light transmitted or reflected by the recording material, and reading the data by determining the polarization-optical contrast between the thermally altered and the unaltered areas and/or utilizing for this purpose the interference of the light rays which form from the laser lightwaves in a Gaussian intensity distribution owing to the different phase velocities of the light in the center of thermally altered areas on the one hand and their thermally unaltered surroundings on the other.

Abstract: A recording apparatus using a disc-shaped recording medium provided with a marker member on the recording medium for detection of the rotation phase thereof includes a phase detector for detecting the marker member while the recording medium is rotating; a delay circuit for delaying the output of the phase detector for a given period of time; a recording circuit for recording signals of the disc-shaped recording medium by means of a magnetic head; and a control circuit which is arranged to supply a current to the recording circuit at the timing of the output of the phase detector and to cause the recording circuit to perform recording at the timing of the output of the delay circuit.

Abstract: A split type optical pick-up device suitable for use in an optical disc memory system has a two-part structure: stationary and movable optical systems which are provided separately. The stationary optical system includes a semiconductor laser for emitting a laser beam which is received by a deflecting member of the movable optical system. The thus deflected laser beam is focused onto an optical disc by an objective lens. The light reflecting from the optical disc passes through the objective lens in the reversed direction and also through the deflecting member to impinge upon a tracking error detector which is also provided in the movable optical system. Because of the provision of the tracking error detector in the movable optical system, there will be produced no offset in a tracking signal generated by the tracking error detector.

Abstract: In a focusing error detecting method for an optical head wherein a laser beam from a laser light source is applied to a magneto-optical recording medium to form an image as a light spot thereon, and a focusing error is detecting according to a reflected light from the magneto-optical recording medium, the focusing error detecting method includes a step of dividing the reflected light from the magneto-optical recording medium into a 0-th order light, a +1-st order light and a -1-st order light by a diffraction grating, a step of applying the +1-st order light and the -1-st order light to a first detector and a second detector, respectively, the first and second detectors being arranged before and behind a beam emitting position of the laser light source, respectively and a step of computing outputs from the first and second detectors to obtain a focusing error signal.

Abstract: Scanning apparatus for a magneto-optical record carrier includes an integrated beam separating and beam splitting element consisting of a supporting body (30) on the surfaces of which are a semi-transparent mirror (22) and a polarization-sensitive beam-splitting layer (26). The semi-transparent mirror separates the scanning beam from the beam reflected from the record carrier. The beam-splitting layer splits the reflected beam into orthogonally polarized sub-beams (27 and 28) which are incident on respective photodiodes or on different regions of a single multiple photodiode. The supporting body may be of a birefringent material which provides orthogonally polarized beam-splitting, in which case the beam splitting layer may be omitted.

Abstract: An optical pickup apparatus having plural light sources which emit laser lights of different wavelengths, a first optical system section for converging and irradiating as light spots the emitted laser lights on a recording medium, a second optical system section for leading the reflected lights on a single optical path of the laser lights, a focusing lens for converging the reflected lights in different focuses according to their respective wavelengths on a single optical axis.

Abstract: There is disclosed a technique whereby digital video signals can be recorded or reproduced on or from a magnetic tape. Using second controller to control a system such as a DAT recorder employing a digital signal processor, and first coutroller for converting said video signals into analog or digital, the video data are processed as in the conventional method of processing audio data according to the input of the mode selecting key. By the input of the key, the first controller converts analog video data into digital to store them in a memory, or reproduce said stored data by converting them into analog of real time, a different input of the key is checked by the second controller to store said video data into the tape.

Abstract: A playback permits two or more recordings associated with time codes to be retrieved synchronously at variable relative speeds. A master playback unit retrieves a master video recording and the associated master time code and a slave playback unit retrieves a slave audio recording and the associated slave time code. A microprocessor scales the slave audio time code to produce virtual slave time code, and the master and virtual slave time codes are compared to produce a virtual offset which is maintained substantially constant with speed control thereby synchronizing the operation of the master and slave playback units. An operator can select the magnitude of the virtual offset, and can also select the scaling factor used to produce the virtual slave code thereby varying the retrieval speed of the slave playback unit relative to the master playback unit, effectively compressing or expanding the slave recording relative to the master recording.

Abstract: A television signal recording and reproducing system is disclosed in which the polarity of a television signal is inverted in polarity prior to its recording on an optical recording medium and is again inverted when it is reproduced to avoid any serious degradation of picture quality.

Abstract: A method and apparatus for previewing recorded information. The apparatus includes a selection of back-lit switches, each of which displays audio or video selection information. A user indicates a desired selection for preview by pressing one of the back-lit switches. An audio and video preview of the desired selection is presented to the user by playback of a optical disc or portion thereof.

Abstract: A loop gain setting method automatically sets the loop gain of a focus servo loop and a tracking servo loop of a disc player for playing a disc. Firstly the loop gains of the focus servo loop and the tracking servo loop are set, and subsequently the appropriateness of the set values of loop gains is judged by comparing the set values of the loop gains with each other. According to another aspect of the present invention the loop gains of the focus servo loop and the tracking servo loop are set, and subsequently the appropriateness of the set values of loop gains is judged by comparing at least one of the set values of the loop gains with a sensed value of the amplitude of the envelope of an RF signal read-out from the disc.

Abstract: Based on an output signal of a sector mark reading circuit reading a sector mark signal representing a sector mark area, the interval in which the next sector mark signal is to be detected is anticipated, and a quasi-sector mark is generated at a time when the next sector mark is to be detected in each sector. Even if the sector mark reading fails, the sector mark will be able to be output at an accurate timing. Also, if the read sector mark signal, which is mis-detected or not, is determined, a highly reliable sector mark signal may be produced.

Abstract: A luminance signal is frequency modulated with an FM carrier to generate a frequency modulated signal having a frequency spectrum within a frequency band of 1.6 to 8 megahertz. A second signal such as a line sequential color signal is single sideband modulated with a second carrier to generate a second modulated signal having a frequency spectrum in the form of a single sideband to one side of the second carrier that is located in a frequency band outside of the frequency band of the frequency modulated signal in a region that is generally empty of frequencies belonging to the frequency modulated signal. The single sideband may be the lower sideband between 0-1.2 megahertz. The two modulated signals are then recorded on a magnetic tape.

Abstract: An optical pick-up apparatus comprises a light beam generating source, an objective lens for causing a light beam from the light beam generating source to impinge upon a record medium and receiving a reflected light beam from the record medium, a composite prism constituted by a glass prism element, a crystal prism element and a multi-layer of dielectric material provided between the glass and crystal prism elements, which are bonded together, and so disposed that the light beam from the beam generating source and the reflected light beam from the objective lens enter into the glass prism element through respective different optical paths, the light beam from the beam generating source is directed to the objective lens after passing through the glass prism element and at least two light beams obtained based on the reflected light beam from the objective lens emerge from the crystal prism element, and a photodetecting unit for detecting separately the light beams emerging from the crystal prism element of the

Abstract: Data recording and/or reproduction on or from a recording medium on which tracking signal detection marks are intermittently provided along each track in a pattern wobbling alternately across the track center line with a very small lateral displacement therefrom, wherein data recording area is defined between the tracking signal detection mark. A servo control system for controlling a write/read light spot so as to follow the track with the aid of a tracking signal obtained by detecting the tracking signal detection marks is provided with a low-pass filter circuit having a cut-off frequency lower than the frequency at which the tracking signal detection marks are detected. A data is recorded or reproduced on or from the recording areas of the recording medium while following the track under the control of the servo system. A blank area where data recording is inhibited is provided between the data recording area and the tracking signal detecting mark (prepit) to suppress interference to the data.

Abstract: To prevent a drop in signal level at high spatial frequencies, an optical information reproducing apparatus retrieves the primary output of light reflected from the surface of a recording medium. In the different embodiments of the invention, either a shield plate with a pinhole in the path of the light is provided, or a photodetector having a plurality of light-receiving elements is provided, a selection circuit being connected to the elements and selecting the highest output thereof.