Abstract: Time-lapse recording/reproducing system and method for recording/reproducing audio signals are provided. The method, in the time-lapse recording/reproducing system for intermittently recording and reproducing predetermined units of a video signal, includes time-compressing an audio signal corresponding to the predetermined unit of a video signal presently recorded and all other corresponding audio signals generated before the predetermined unit of a video signal to be next recorded, to record the time-compressed audio signals between the predetermined units of a video signal. The method further includes sequentially outputting time compressed audio signals corresponding to the predetermined unit of the video signal while reproducing the predetermined unit of the video signal as a still image. Accordingly, an audio signal corresponding to a video signal can be recorded and reproduced without loss in a time-lapse recording/reproducing system.

Abstract: A variable speed playback method and apparatus is provided. The variable speed playback apparatus includes a transfer unit for moving a recording medium, a controller for controlling the transfer unit so as to repeatedly perform a fast transfer operation for moving the recording medium at a high speed and a normal playback operation for playing back the data of the recording medium at a normal playback speed after the fast transfer operation, and a restoring unit for reconstructing data, which is read from the recording medium during each period of the normal playback operation, to at least one picture of display data, thereby easily implementing variable speed playback without increasing the cost or structural complication of products.

Abstract: A data detector and a data detection method. The data detector includes: a converter for converting a received signal into digital data according to a sampling clock signal; a maximum likelihood decoder for performing maximum likelihood decoding of the digital data; and a generator for measuring a phase difference between sampling points of the digital data and optimal detection points of the received signal, and for generating a control signal for changing the phase of the sampling clock signal according to the measured phase difference. The phase of the sampling points as the data detection points matches that of the optimal detection points, so that error caused by difference in phase is minimized, thereby enhancing the performance of the maximum likelihood decoder, and the overall performance in detection of reproduced data.

Abstract: A data detector and a data detection method. The data detector includes: a converter for converting received data into digital data according to a sampling clock signal; a maximum likelihood decoder for performing maximum likelihood decoding on the digital data; and a generator for measuring a phase difference between the digital data sampled at a desired detection point among a predetermined number of optimal detection points of the received signal and each of a number of reference levels according to the predetermined number of optimal detection points. The generator further generates a control signal for changing the phase of the sampling clock signal according to the measured phase difference. The phase of the sampling points, as data detection points, is made to match the phase of optimal detection points, so that errors caused by differences in phase are minimized, thereby enhancing performance of the maximum likelihood decoder, and enhancing performed in the overall detection of reproduced data.

Abstract: A data decoding apparatus and method are provided for decoding a reproduction signal in a digital magnetic recording/reproducing apparatus. A Viterbi decoder having a single channel is constructed such that the noise level corresponds to that of an EnPR4 system and the aperture ratio of an eye pattern corresponds to that of a PR(+1, −1) system, thereby improving the efficiency of the Viterbi decoder and allowing state detection by the PR(+1, −1) system. Data can be decoded by a system having a PR4 or EnPR4 channel or selectively by other various systems.

Abstract: A peak detector for a maximum likelihood decoding system, using an automatic threshold control (ACT), and a method therefor are provided. In the peak detector, positive and negative peak values are detected from an input signal having digital information, based on positive and negative threshold values, and then each threshold value is evaluated according to positive and negative values of the input signal, to reset each threshold value to a predetermined value based on the detected peak value having the opposite polarity thereto. Accordingly, data can be detected exactly, improving performance of Viterbi decoding.

Abstract: A crosstalk removing apparatus for digital magnetic reproduction is provided in which a clamp circuit is connected between a playback amplifier and a playback equalizer. An effect of crosstalk from a neighboring track is effectively removed using the clamp circuit including two capacitors, two diodes and a load resistor. The clamp circuit improves a quality of picture of the reproduced signal while maintaining compatibility between recording a reproducing apparatus.

Abstract: A Viterbi decoding circuit for decoding an input signal is provided. The circuit contains a detector, a first converter, a Viterbi decoder, a second converter, and a selector. The input signal is grouped into a current and subsequent input signal group. The detector detects negative peak data values and positive peak data values from the current input signal group. The first converter converts the positive and negative peak data in a reverse direction to produce reverse positive and negative peak data, respectively. The Viterbi-decoder decodes the reverse positive and negative peak data with respect to a predetermined number of initial states and generates current reverse decoded data groups which respectively correspond to a plurality of channels and respectively correspond to the initial states. In addition, the Viterbi decoder generates a control signal based on a state of initial decoded data corresponding to the subsequent input signal group.

Abstract: An analog and digital combination recording and reproduction apparatus uses the existing head layout found in an analog recording and reproduction apparatus such as an existing VHS system, for recording and reproduction of both analog and digital signals on a magnetic tape. Using a video signal head or a hi-fi audio signal head for use in an extended play mode, digital video and audio signals are simultaneously recorded on tracks obtained by bisecting the standard play mode track width. Thus, the analog and digital signals can be recorded and reproduced without having additional heads for digital recording and reproduction, thereby providing a simple structure and minimizing costs.

Abstract: Magnetic recording device and method are provided. The magnetic recording device includes a shaping driver for positive and negative signals whose polarities are reversed, corresponding to the digital information, a push-pull portion for generating a recording current corresponding to the positive and negative signals and generating a transient pulse current during reversal of the polarity of the recording current, and a current switch for switching a current flowing through the push-pull portion in response to the positive and negative signals. The digital signal is recorded on the magnetic recording medium on the basis of the transient pulse current. Therefore, without an additional recording equalizer, rise characteristics of a head current is improved and the demand of small-size and low-power is satisfied.

Abstract: An 8 mm image recording/reproducing apparatus is provided which is capable of searching for information recorded on a video tape based on signals recorded on a track of the video tape. Furthermore, the apparatus is capable of performing tracking control in accordance with reference pilot signals. The apparatus contains a controller, a pilot signal generator, a search reference signal generator, a recording/reproducing section, and an index signal separator. The controller generates a mode selection signal and a pilot selection signal, and the mode selection signal indicates whether the apparatus is operating in an index signal record mode or an index signal separation mode. The pilot signal generator sequentially and cyclically generates the reference pilot signals. The search reference signal generator generates an index signal and an index separation reference signal based on at least is one of the mode selection signal and the pilot selection signal.

Abstract: A circuit for automatic control of delay time between luminance and chrominance signals is disclosed. The delay time control circuit of the present invention comprises: a clock pulse generator that passes a certain number of clock pulses during a period of time between the positive-going edge of the horizontal synchronizing signal from a horizontal synchronizing separator and the leading edge of the color burst signal from a color burst signal separator; a comparator that compares the number resultant clock pulses to a reference value and determines which signal (the luminance or the chrominance signal) is delayed and the length of the delay time; a luminance delay circuit and a chrominance delay circuit that delay the luminance and chrominance signal respectively according to outputs of the comparator; and a luma/chroma mixer that mixes the delayed luminance and chrominance signals.