Hitachi, Ltd.

Toshio Nakamoto

Hideo Nishijima

Kouji Kaniwa

Katsuyuki Watanabe

Hiroya Abe

Hiroyuki Torii

Koichi A Ono

Fumio Tajima

Shigeki Morinaga

Hiroshi Katayama

Nobuyoshi Mutoh

Taizo Miyazaki

Yuji Sato

Seiichi Narushima

Toshio Osada

Takashi Takahashi

An apparatus for recording/reproducing video and audio signals on/from a recording medium includes a first and second tuner which receive a video signal of a first and second format transmitted by broadcasting, respectively; a recorder which records the video signal of the first format from the first tuner on the recording medium; a reproducer which reproduces the video signal of the first format from the recording medium; and a decoder which decodes the video signal of first format from the reproducer and converts the decoded signal to another video signal of the second format. A switching circuit is provided which selects one of the another video signal of the second format and the video signal of the second format as a selected video signal, and a video output terminal outputs the selected video signal through an on-screen display unit.

Digital/analog compatible video tape recorder

A helical scanning video tape recorder for recording and reproducing video signals and audio signals to/from a magnetic tape. The video tape recorder includes an analog signal reproducing mode in which an FM luminance signal and a down-converted chrominance signal are reproduced from the magnetic tape by a pair of magnetic heads having a first azimuth angle and an FM audio signal is reproduced from a deep layer of the magnetic tape by a pair of magnetic heads having a second azimuth angle, and a digital signal reproducing mode in which a digital signal is reproduced from the magnetic tape by the pair of magnetic heads having the second azimuth angle. The digital signal is converted into a signal having a frequency in a frequency band higher than a frequency of the FM audio is signal. The video type recorder also includes a recording mode detector and a controller.

A VTR compatible with the current analog VTR and capable of recording and reproducing digital signals, determines the presence or absence of recorded digital signals and selects an operating mode for recording and reproducing in accordance therewith.

A VTR compatible with the current analog VTR and capable of recording and reproducing digital signals identifies the type of a tape cassette by the presence or absence of a cassette identification hole formed in a digital recording tape cassette determines tape speed for a recording mode on the basis of the ratio between the frequency of a control signal and the rotating speed of a capstan motor, determines the presence or absence of recorded digital signals through the synchronous detection of reproduced output, and decides the mode for recording and reproducing on the basis of those decisions. Thus, the automatic discrimination between the analog mode and the digital mode can be achieved and erroneous operations, such as an erroneous erasing operation can be prevented.

A digital tracking device for use in a helical scan type magnetic recording and reproducing apparatus with an ATF system utilizing four-frequency pilot signals includes a sampling circuit which samples reproduced pilot signals with a frequency of a predetermined one of the four pilot signal frequencies, digital filter circuits for deriving aliasing signal components of the predetermined pilot signal produced by the sampling circuits, and a feedback circuit for feeding back a tracking error signal corresponding to signal levels of the aliasing signal components derived by the digital filter circuits to a magnetic tape drive system of the recording and reproducing apparatus.

Tracking device

A speed control apparatus in which for sampling features of a speed fluctuation and generating a speed fluctuation correcting signal, an arithmetic operation can be simplified and can be performed by an inexpensive arithmetic and operation unit, thus requiring no expensive arithmetic operation unit. The speed control apparatus is also capable of reducing torque ripples and speed fluctuations quickly even when the load of an object to be controlled is changed.

Growing community of inventors

Hitachinaka, Japan

Toshio Nakamoto