Sony Corporation

Soshin Electric Co., Ltd.

Michimasa Komatsubara

Akira Sakamoto

Takeshi Fukami

Takehiro Sugita

Masakatsu Toyoshima

Toshihiko Waku

Tetsuya Naruse

Akira Shimizu

Jun Iwasaki

Masato Yamagata

Noboru Someno

Mitsuo Higashiyama

Ikuo Shimizu

Toshiya Miyata

Kaname Mori

Teruo Masaki

Tetsuya Fukai

Akito Satsuka

A synthesis signal which was reproduced from reproducing apparatus and converted into an analog signal includes an analog information signal and a copy control code. The copy control code is modulated by a spread spectrum. A code reading unit of the recording apparatus extracts the copy control code by an inverse spread spectrum. A code changing unit changes the copy control code by a spread spectrum as necessary. An output signal of the code changing unit is converted into a digital signal. The digital signal is subjected to processes necessary for recording and is recorded to a recording medium.

Apparatus and method for synthesizing information signal and

Apparatus for transmitting and receiving signals for use with a so-called cordless telephone, in which an audio signal and an identification code signal are transmitted and received by both the handset and base unit of the telephone and when the identification code signal is not correctly detected, as might be caused by cross-talk interference, the transmitter is disabled and a vacant communication channel is searched for and a communication channel is changed to thereby prevent a cross-talk interference. The unit that does not correctly receive the code signal immediately disables its transmitter and searches for a vacant channel and, because the code signal had been alternately transmitted and received between the two units, the other unit detects the stoppage of code signal transmission, disables its own transmitter, and then also moves to the next vacant channel to await further transmission of the code signal.

Apparatus for transmitting and recording signals

A digital signal composing circuit includes a first selector for selecting a plurality of digital data, a second selector for selecting one of the digital data and a feedback signal, a control circuit for controlling the switching of the first and second selectors and an adding circuit for adding outputs of the first and second selectors and supplying the added output to the second selector as the feedback signal wherein the final output is derived from the adding circuit. Thus, without using any multiplier, the signal processing can be widely used in the digital signal processing such as digital volume, cross-fade, fade-in/-out, mixing, linear interpolation and the like.

Digital signal composing circuit for cross-fade signal processing

A scrambling system for an audio frequency signal in which an audio signal is divided into blocks, each block being formed of a plurality of frames, the plurality of frames are rearranged on a timebase in a predetermined order at every block so as to be encoded and the encoded signal is re-arranged on the timebase in an original order so as to be decoded, in which there are provided a first signal processing circuit for inserting a redundant portion into a portion between adjoining frames and timebase-compressing the frames in response to the redundant portions upon encoding, a control signal generating circuit for inserting a control signal other than an audio information into the redundant portions, a control signal detecting circuit for detecting the control signal upon decoding and a second signal processing circuit for removing the redundant portions in synchronism with the detected control signal and timebase-expanding the frames in response to the redundant portions. Therefore, even when the audio signal is transmitted through a system in a transmission path having a timebase fluctuation such as a transmission path of a VTR (video tape recorder) and the like the frequency band region of which is restricted, the signal waveform is not distorted and a noise is not mixed therein so that the scrambling communication having high quality and high reliability can be presented.

Scrambling system for audio frequency signals

A system for detecting a marker signal with a predetermined pattern inserted periodically in an information signal comprises a circuit which repetitively generates window signals and successively shifts the window signals in a step-wise fashion during a predetermined interval, a detecting circuit which employs the window signals to detect at least a portion of a marker signal in the information signal when at least the portion of the detected marker signal occurs during one of the window signals, a circuit which determines when the detected marker signal has the predetermined pattern to generate a net marker signal in response thereto, and a circuit responsive to the net marker signal which repetitively generates subsequent unshifted window signals beginning a predetermined time after the detected marker signal.

System for detecting a marker signal inserted in an information signal

In tuning apparatus, a sensor senses when a tune indicating signal has been produced by the IF section so as to enable an adjusting circuit to change the tuning condition of the apparatus by a predetermined frequency step and then to disable the adjusting circuit if the tune indicating signal still is sensed following this frequency change so as to maintain the last-attained tuning condition. Alternatively, if the tune indicating signal no longer is sensed after the tuning condition has been changed by the predetermined frequency step, the tuning section is returned to its preceding tuning condition by this predetermined frequency step. Consequently, if the received signal is a high level signal at a frequency within a predetermined range from a broadcast frequency, the tune indicating signal is produced when the tuning condition of the tuning section differs from the broadcast frequency by this predetermined frequency step; and the tuning condition then is changed by this step so as to arrive at the desired broadcast frequency. If, however, the received signal is a low level signal, the tune indicating signal is produced only when the tuning condition of the tuning section coincides with a desired broadcast frequency, and then this tuning condition is changed by one step followed by a return of one step to the proper condition.

Tuning apparatus

In a teaching system having a central or master station and one or more student stations remote from the master station, there are provided, at the master station, at least one source of main signals in a first frequency band, which source may be constituted by a tape or other record player for reproducing teaching or instructional materials, a microphone or other source of audio signals from a proctor or supervisor of the teaching system, and a source of control signals which may include address signals for identifying one of the student stations and command signals for controlling various operations of the addressed student station. The audio and control signals are employed to modulate respective carriers so as to provide first and second auxiliary signals, respectively, in frequency bands which are removed from each other and from the first frequency band of the main signals, whereupon the main signals and the first and second auxiliary signals are multiplexed to provide a composite signal which, in turn, modulates a carrier of predetermined frequency suitable for being transmitted to each of the student stations.

Signal transmission in teaching system

A printed circuit including a first conductor formed on an insulating plate as an inductance element, a second conductor formed on the insulating plate as an inductance element which is inductively coupled to the first element, and a common conductor formed on the insulating plate between the first and second elements and mutually inductively coupled to the first and second elements to provide a predetermined desired coefficient of coupling between the first and second elements. A preferred detailed form of the invention additionally includes printed capacitor elements in circuit with the inductance elements to provide an electric band-pass wave filter.

Growing community of inventors

Chiba, Japan

Michimasa Komatsubara