Hitachi, Ltd.

Hitachi America, Ltd.

Nippon Hoso' Kyokai

Hitachi Electronics Co., Ltd.

Nippon Noso Kyokai

Katsuo Mohri

Takaharu Noguchi

Jill MacDonald Boyce

Hiroo Okamoto

Yoshizumi Watatani

Frank Anton Lane

Masuo Oku

Masafumi Nakamura

John G Henderson

Michael Allen Plotnick

Nobuo Azuma

Takashi Furuhata

Jack S Fuhrer

Joseph Ellis Augenbraun

Takehiko Yoshino

Yuuhei Abe

Kenji Satoh

Yuhiko Yabe

Takao Arai

Hitoaki Owashi

Shigeyuki Itoh

Yoshinori Okada

Kyoichi Hosokawa

Michio Masuda

Hideo Arai

Kazutaka Naka

Kentaro Hanma

Yasufumi Yumde

Hiroaki Nabeyama

Shigeyuki Ito

Toshifumi Shibuya

Katsuo Konishi

Toshimichi Terada

Masaaki Fukuda

Tatsuo Kayano

Yoshinori Masuda

Toshiaki Kawamura

Jack Selig Fuhrer

Yasunori Tominaga

Fujio Okamura

Fuzio Okamura

Kazuyoski Kuwahara

Michio Ozawa

A digital video tape recorder ('VTR') that selects data useful for generating images during trick playback operation and records the data in trick play tape segments arranged on a tape to form fast scan tracks and multi-speed playback tracks. Each fast scan track comprises trick play tape segments located on a diagonal, relative to the length of the tape, of the same angle as the angle at which the heads of a VTR are expected to pass over the tape during trick play operation at a specific speed and direction of operation. Each multi-speed playback track comprises a plurality of trick play tape segments arranged parallel to the length of the tape. Data which is used for at least one mode of trick play operation is recorded in each trick play tape segment. Each fast scan track and multi-speed track crosses multiple normal play tracks. During playback at a wide variety of speeds and directions, the heads pass over enough trick play segments of the multi-speed playback track to generate recognizable images during trick play operation. Data is recorded in each trick play segment in a manner that optimizes the amount of data that can be routinely recovered during trick playback operation despite tracking errors.

Methods and apparatus for recording data on a digital storage medium in

Methods of operating a digital video recording and playback device to identify trick play data, e.g., data that is intended for use during trick play modes of video playback device operation such as fast forward and reverse, by recording headers containing specific trick play information along with the trick play data are described. In one embodiment, the recording of headers which identify data as data intended for use during trick play as opposed to normal play operation is described. In addition to identifying data recorded data as normal play or trick play data headers associated with recorded data may identify the speed and direction of video tape recorder operation during which the specific data associated with the header is intended to be displayed at. When a data block includes data packets, a header may be used to identify various ones of the data packets as being for use during one mode of trick play operation, e.g., a first fast forward speed of operation, and other packets in the same data block as being for use during a second mode of trick play operation.

Trick play data indentification methods and apparatus for use with

Digital video recording device with trick play capability

Methods of operating a digital video recording and playback device, such as a video tape recorder, to arrange trick play data into one or more groups, to generate error correction bits for each group of trick play data, e.g., a group of trick play data blocks, and to correct the data after being read back using the error correction bits is disclosed. The trick play data blocks are made to be smaller than normal play data blocks with multiple trick play data blocks being equal in size to a single normal play data block. By making a group of trick play data blocks equal in size to a single normal play data block, the group of trick play data blocks may be processed as a unit by the same error correction circuitry and in the same manner used to process individual normal play data blocks. In accordance with one embodiment, the error correction bits for a group of trick play data blocks are calculated treating the data in the group of trick play data blocks as a single unit. The error correction bits are appended to the last data block in the group of trick play data blocks. During trick play operation the trick play data blocks are read back and combined according to trick play data groups. Each group of trick play blocks is then processed using the same error correction circuitry used to process a normal play data block.

Digital recording and playback device error correction methods and

An apparatus for storing high definition image signals capable of processing high definition image signals and low definition image signals using the same apparatus. A storage medium is provided with an interface of low definition image signals. High definition image signals are compressed, transformed into a format according to the specifications of the interface of low definition image signals and are then stored in the storage medium. The compressed image signals taken out from the storage medium are subjected to the format reverse transform for expansion to restore the original high definition image signals. The format-transformed compressed high definition image signals and the compressed high definition image signals taken out from the storage medium are transmitted over a transmission medium via low definition image interface and are, as required, stored in the storage medium or put to other processings, and are then expanded to restore the original high definition image signals.

Apparatus and method of storing image signals

A method of producing a tracking control signal in a rotary head type magnetic recording and reproducing apparatus and a rotary head type magnetic recording and reproducing apparatus capable of a proper tracking by the use of the tracking control signal. First and second tracking signals are recorded on local portions of each odd-numbered track and the first tracking signal and a third tracking signal are recorded on local portions of each even-numbered track in such a manner that the second tracking signals on two odd-numbered track adjacent to any one even-numbered track are not overlapped with each other and the third tracking signals on two even-numbered tracks adjacent to any one odd-numbered track are not overlapped with each other when viewed in a direction perpendicular to the longitudinal direction of the tracks; upon scanning of a track crosstalk signals are detected from two adjacent track simultaneously with reproduction of the first and second or third tracking signals; and the detected crosstalk signals are compared by the use of timing of the reproduction of the first tracking signal for each track thereby producing a tracking control signal. The second tracking signal may have a frequency equal to that of the third tracking frequency.

Rotary head type magnetic recording and reproducing apparatus and method

The rotary head type helical scanning magnetic tape recording and reproducing apparatus is provided with an auxiliary recording head for recording pilot signals adjacent to a main head for recording a signal to be recorded, and an auxiliary reproducing head for reproducing the recorded pilot signals. The pilot signals recorded to an antecedent track are reproduced by the auxiliary reproducing head at the time of recording to the next track. A tracking control of the main head at the time of next track recording is effected according to the reproduced pilot signals.

Magnetic recording and reproducing apparatus

An apparatus for detecting and compensating for the drop-out in a video tape recorder in which an FM audio signal is recorded on a magnetic tape and is reproduced therefrom utilizing a rotary magnetic head. In a playback mode, a frequency demodulator demodulates the reproduced FM audio signal. The reproduced FM audio signal is supplied to a synchronous detector and synchronously detected with an output signal of the frequency demodulator. An output signal of the synchronous detector is supplied through an integrator to a drop-out discriminator which detects a drop-out generating period and provides an output indicative thereof.

Apparatus for detecting a drop-out in a magnetic recording/reproducing

A method and apparatus for reproducing information at variable speeds from a magnetic tape by correcting a deviation between at least one video track of the magnetic tape and a rotating head during a tape stop state of an intermittent drive for a noiseless slow-still picture in a video tape recorder using pilot signals. A series of pulses produced by a frequency generator of a capstan for feeding the tape is counted during the tape feeding state of an intermittent drive in order to detect a timing of the stopping of the tape feeding. As the count number equals a set value corresponding to a regular amount of feeding of the tape during the intermittent drive, the tape feeding is controlled to stop. A tracking error signal is produced from the pilot signals reproduced from the tape by the rotating head within the tape stop state of the intermittent drive and the set value for the next tape feeding of the intermittent drive is adjusted in response to the tracking error signal.

Method and apparatus for reproducing information at variable speeds from

A device for controlling consecutive recording of video information containing signals, on a magnetic recording medium in a magnetic recording and reproducing apparatus, fed from a video camera with variable time spacing. The device comprises a control switch rendered non-conductive or conductive when a pause switch in the magnetic recording and reproducing apparatus is actuated or released, and a member for initializing a sync signal generator in the video camera with a signal produced in synchronism with the rotation of a head carrying disc driving motor of the magnetic recording and reproducing apparatus, whereby energy consumption is lowered and synchronization between successive video information signals is attained rapidly during the consecutive recording of video information signals from the video camera.

Device for controlling consecutive recording of video information

A sound signal recording and reproducing device for use in a picture signal recording and reproducing apparatus comprises a first sound signal recording and reproducing system recording a sound signal in superposed relation with a picture signal on the same track on a magnetic tape by a rotary head, and a second sound signal recording and reproducing system capable of recording a sound signal independently of the picture signal by a stationary head in a direction parallel with the traveling direction of the magnetic tape.

Video and sound signal recording and reproducing device

In a video tape recorder or audio tape recorder, the remaining tape length indicated as time or taken-up tape length indicated as time is calculated by use of microcomputer and then accurately indicated as a time length by detecting the angular velocities of a supply reel and a take-up reel. A rotational period of time of each reel is detected twice, so that the tape running speed is calculated from the two detected values and the known tape caliper thickness, thus calculating and indicating the remaining tape length indicated as time and the taken-up tape length indicated as time. The remaining tape length and taken-up tape length indicated as time in such operation modes of a tape recorder as fast forward, and rewind, as well as recording and reproduction are accurately indicated.

Tape running time indication system

A programmed timer for presetting a video tape recorder for the time and reception channel when the video tape recorder starts and ends, comprising a processor circuit for processing the type of the data entered for reservation in a predetermined order, and means for sequentially displaying a procedure to be next entered each time data are entered. The operator is required to enter the necessary data simply according to the displayed procedure in order to set the desired reservation data for the programmed timer.

Programmed timer for VTR

A relay control circuit is disclosed in which a timer circuit is actuated by a reference clock pulse in synchronism with an AC voltage supplied by a commercial power supply. An output signal of the timer circuit causes current to flow in the coil of the relay thereby to close the contact of a relay. The invention further comprises a polarity-reversing device for reversing the polarity in accordance with the variations in the output signal of the timer circuit. The reference clock pulse is applied to the timer circuit through the polarity-reversing device.

Relay control circuit

An automatic control apparatus for protecting the compressor motor used with the refrigeration system of an air conditioning unit. The control apparatus has a timer for prohibiting the restart of the compressor motor until the lapse of a predetermined time after temporary stoppage of the compressor motor, and a holding circuit for holding a power source voltage for a predetermined period of time while the operation of the air conditioning unit is stopped. Even if the power supply is turned off, therefore, the source voltage supplied by the holding circuit enables the timer circuit to continue its operation for a predetermined length of time.

Control apparatus for air conditioning unit

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Yokosuka, Japan

Katsuo Mohri