摘要:
A circuit for automatically controlling horizontal scanning frequency, used in the horizontal deflecting circuit of a display device which displays a still picture by repeatedly reading television signal for a single field stored in a field memory. The automatic frequency control circuit comprises a circuit for generating two horizontal sync signals which are 180.degree. out of phase from each other and a circuit for changing over the two signals at a period of the single field. Thus, a proper sequence of odd and even fields is obtained.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A multi-level code transmission system for restoring the d.c. component of a received signal by peak-clamping of the peak of the received synchronizing signal to a fixed level so as to establish the synchronization of a receiving end prior to an establishment of synchronization at the receiving end and for effecting pulse-clamping of the reference level of a following received signal after the establishment of synchronization at the timing of a clamping pulse relating to the synchronizing signal. In the case of transmitting a multi-level code signal such as an audio PCM signal together with an analogue signal such as a picture signal alternately, for example in a still picture transmission system, the d.c. level of the received signal is varied due to the low cutoff frequency characteristic of the transmission line, the result of which is the occurrence of a code error in a reproduced code signal at the receiving end. In order to obviate such a code error, the present invention uses two kinds of clamping, i.e., peak-clamping and pulse-clamping before and after the establishment of synchronization at the receiving end, respectively. According to this invention, the multi-level code signal can be reproduced with high fidelity.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.