Abstract: A storage medium has at least one diffraction grating. The diffraction grating is formed as a holographic interference fringe pattern. The pattern is formed as it two-dimensionally diffracts an incident light beam in a plurality of directions or one-dimensionally diffracts an incident light beam in a direction. A combination of such patterns and also a plurality of rows of such patterns on the storage medium are available. A light beam is radiated to the storage medium. The light beam diffracted in the direction(s) is detected by a photodetector, such as a CCD device, that generates a signal carrying data stored as the holographic interference fringe pattern. The signal is then decoded by a processor to reproduce the data.

Abstract: An optical recording medium includes a transparent substrate having a surface formed with a track of pits. A reflecting layer extends on the surface of the transparent substrate. The pits include first-type pits and second-type pits. The first-type pits are devoid of projecting rims extending along edges thereof while the second-type pits have projecting rims extending along edges thereof.

Abstract: An optical information storage medium is provided which may be employed as a prepaid card usable as money in limited stores. The optical information storage medium includes a function writable chip which consists of a plurality of memory areas each including a writable region in which information can be written once by a scan of a given beam of light and a read-only region storing therein given information which can be read out by a scan of a given beam of light. Each of the read-only regions includes a scanning guide section and an address storage section.

Abstract: An optical disc for a key physically stores first security information. The optical disc logically stores second security information. The first security information is equal to security information physically recorded on a legitimate optical disc. The second security information is equal to security information logically recorded on the legitimate optical disc.

Abstract: A variable transfer rate control coding apparatus which can distribute codes of an amount most suitable to the contents of a moving picture to be recorded and to a recording medium, on which information is recorded by this transfer rate coding apparatus, by obtaining an amount of codes to be temporarily generated in each unit period of time by a temporary or tentative coding, and then storing a temporary transfer rate (namely, a value of the temporary amount of codes to be generated in each unit period of time), and setting a target transfer rate (namely, a target value of an amount) of codes to be sent in each unit period of time from a total of the temporary transfer rates and the recordable capacity of the recording medium and next performing an actual or real coding according to the target transfer rates.

Abstract: An optical recording medium includes a transparent substrate having a surface formed with a track of pits. A reflecting layer extends on the surface of the transparent substrate. The pits include first-type pits and second-type pits. The first-type pits are devoid of projecting rims extending along edges thereof while the second-type pits have projecting rims extending along edges thereof.

Abstract: An optical disc on which a number of spiral trains of regular pits and at least one train of irregular pits are formed. The regular pits of each of the trains is arranged symmetrically with respect to the center of a track. Each of the irregular pits has a predetermined shape different from a shape of each of the regular pits. An arrangement of the train of the irregular pits being differs from an arrangement of each of the trains of the regular pits. A tracking error signal being obtained from the train of the irregular pits. An irregular pit can not be copied even when a normal optical disc containing such an irregular pit is copied by performing a conventional copying method. Thus, an illegal copy disc can be discriminated from a normal optical disc by checking whether or not an irregular pit is included in an optical disc to provide good copy protection by easily detecting an illegal copy disc.

Abstract: An optical recording medium includes a transparent substrate having a surface formed with a track of pits. A reflecting layer extends on the surface of the transparent substrate. The pits include first-type pits and second-type pits. The first-type pits are devoid of projecting rims extending along edges thereof while the second-type pits have projecting rims extending along edges thereof.

Abstract: An optical disc has a sequence of pits which extends along a track. The pit sequence represents a recorded signal divided into data blocks. The pit sequence includes a normal pit train and an unusual pit train. The normal pit train is symmetrical with respect to a center of the track. The unusual pit train is different from the normal pit train in at least one of shape and pit arrangement. The unusual pit train is at a position having a predetermined relation with the data blocks.

Abstract: A reflective optical rotary encoder device detects an angular speed or position of a rotatable member with a light beam applied to and reflected from a reflective optical encoder disc. The reflective optical rotary encoder disc has an annular encoder track for reflecting the light beam, the encoder track being composed of an annular pattern of angularly spaced pit units each including a plurality of radially spaced arcuate pits, and a pit-free annular focus servo track for focusing the light beam onto the encoder track, the focus servo track extending along and being disposed radially substantially centrally in the annular encoder track.

Abstract: A film thickness measuring apparatus comprises a light source for impinging light on a measuring plate with a predetermined incident angle .theta..sub.0, where the measuring plate comprises a transparent film on top of a transparent substrate and the transparent film has a film thickness which is to be measured by the film thickness measuring apparatus, a light receiving system for receiving and detecting light which is impinged on the measuring plate and is reflected thereby, and an analyzer system responsive to an output of the light receiving system for measuring an angle .DELTA. of the phase difference between two polarized light components of the reflected light from the measuring plate and for calculating the film thickness of the transparent film from the angle .DELTA. of the phase difference. The incident angle .theta..sub.0 of the light from the light source with respect to the measuring plate is selected equal to or approximately equal to a polarizing angle .theta..sub.

Abstract: A rotating analyzer type ellipsometer comprises a rotating analyzer for receiving light which is impinged on a sample with a predetermined incident angle and reflected by the sample, a rotary phase detecting apparatus provided so as to rotate unitarily with the rotating analyzer for generating a rotary phase signal as the rotary phase detecting apparatus rotates, a rotating mechanism for rotating the rotating analyzer and the rotary phase detecting apparatus, a photodetector for producing an output responsive to light which is passed through the rotating analyzer, and a computer for obtaining a phase difference between the rotating analyzer and the rotary phase detecting apparatus from a phase difference .phi..sub.o with which a difference between an output I.sub.p of the photodetector and a theoretical value I.sub.o becomes a minimum or substantially zero by entering into the computer the output I.sub.p of the photodetector and calculating the theoretical value I.sub.

Abstract: A special reproducing system is applied to apparatus for reproducing a video signal from a grooveless rotary recording medium. Video signals are recorded along a spiral track with a plural number of fields recorded on every revolution of the medium.

Abstract: The feeding device feeds a reproducing transducer in an apparatus for reproducing signals from a rotary recording medium having an information signal recording track formed thereon in a spiral path or concentric circular form and having reference signals recorded thereon interrelatedly with the information signal track. The reproducing transducer has a reproducing element for reproducing the information signal and the reference signals recorded on the rotary recording medium and tracking control mechanism for accomplishing tracking control so that the reproducing element traces the information signal track.

Abstract: A bias control circuit for light modulator includes a feedback control loop through which a measure of the modulated laser beam is processed to derive an error correction signal which is superimposed on the normal bias potential to shift the bias point in the same direction as the direction of shift of the operating curve of the light modulator due to the heat generated therein during operation. A feed-forward control loop is also provided to cancel an error signal in the feedback control loop resulting from an intentional gradial variation of the laser beam intensity prior to the modulation so that the average light intensity of the modulated laser beam is correspondingly varied.

Abstract: In an optoelectronic audio/video recording system wherein a laser beam which is subject to undesired broad-spectrum noise is intensity modulated by a light modulator with an audio/video intelligence signal, a feedback control loop is provided including a half-silvered mirror disposed in the path of the beam to transmit a greater part of the light energy to the light modulator and to reflect some of the light to a photoelectrical transducer to convert the reflected light into corresponding electrical signal, a plurality of filter-amplifier circuits for dividing the frequency spectrum of the signal into a plurality of separate frequency bands to provide outputs accentuated such that each output has a particular amplitude versus frequency characteristic corresponding to a portion of the noise spectrum, and a second light modulator disposed in the path of the beam incident to the half-silvered mirror to effect the intensity modulation of the beam with the outputs from the separate filter-amplifiers to suppress th

Abstract: A first pulse is electromechanically generated for each rotation of a body and a predetermined number of second pulses are also electromechanically generated for each rotation. The first pulse is applied as an input binary digit to a shift register having storage elements equal in number to the second pulses generated for each rotation. The second pulses are applied as a clock input to the shift register to cause shifting of the binary digit through the storage elements in a step along manner. A plurality of monostable multivibrators are coupled to respective ones of the storage elements to receive the stored content in each storage element. Each of the multivibrators is provided with a manually adjustable time constant value. Adjustment is made of each time constant value to compensate for any possible error in spacing between successive ones of the second pulses due to mechanical tolerances in the manufacture of the electromechanical pulse generating mechanism.

Abstract: A variable transfer rate control coding apparatus which can distribute codes of an amount most suitable to the contents of a moving picture to be recorded and to a recording medium, on which information is recorded by this transfer rate coding apparatus, by obtaining an amount of codes to be temporarily generated in each unit period of time by a temporary or tentative coding, and then storing a temporary transfer rate (namely, a value of the temporary amount of codes to be generated in each unit period of time), and setting a target transfer rate (namely, a target value of an amount) of codes to be sent in each unit period of time from a total of the temporary transfer rates and the recordable capacity of the recording medium and next performing an actual or real coding according to the target transfer rates.