Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Manabu Tsukamoto

Yoshinobu Ishida

Masayuki Ishida

Kazuhito Endo

Nobuaki Hirai

Kenji Goto

Yuji Kawano

Kazuyasu Nishikawa

Hiroshi Kobayashi

Yoshinori Tatenuma

Hideki Shimauchi

Ken Onishi

Takaaki Murakami

Yoshinori Asamura

Masahiro Yokotani

Takashi Itou

Takehiko Umeyama

Yuji Ariyoshi

Takashi Tokunaga

Yoshiko Hatano

Masayoshi Shimamoto

Takahiro Ohnakado

Yoshiji Inoue

Yasuhiro Kosasayama

A distortion of a signal of a magnetic position detection device is reduced so that precise position information at a high degree of accuracy can be obtained. The magnetic position detection deviceincludes a magnetic movable body, a bridge circuit, a correction circuit, and a detection circuit. The magnetic movable bodyis magnetized so that N-poles and S-poles alternately appear and has a region in which distances between the N-poles and the S-poles are constant. The bridge circuitis formed of first, second, third, and fourth field detection portionsRRR, andR. The correction circuitis formed of fifth and sixth field detection portionsRandR. The detection circuitdetects a position of the magnetic movable bodyon the basis of a differential output Vout of the bridge circuit.

Magnetic position detection device

A differential amplifier generates an offset correction signal based on a rotation detection signal from a rotation detector apparatus and an offset signal. A comparator compares the offset correction signal with a threshold voltage, and outputs a binarized signal representing the comparison result. An average value signal generator circuit generates an average value signal representing the average value of the offset correction signal. The offset signal generator circuit generates the offset signal so that the signal voltage of the average value signal has a voltage value between a threshold voltage and a threshold voltage.

Binarization circuit for binarizing detection signal representing rotation or movement of object

A magnetic detection apparatus includes a first comparison circuit that waveform-shapes the amplitude of a detection signal from magneto-electric transducers by DC coupling, a third comparison circuit that waveform-shapes the detection signal by AC coupling, an oscillation circuit having a natural frequency, a control circuit that counts the output of the first comparison circuit by using the oscillation means, and a selection circuit that selects the output of the first comparison means and the output of the second comparison means. The control circuit counts rising from the next rising or falling from the next falling of an output rectangular wave of the first comparison circuit, and provides output to the selection circuit at the time point at which the count value reaches a desired value. The selection circuit selects and outputs the output rectangular wave of the first comparison circuit or the third comparison circuit.

Magnetic detection apparatus

A rotation state detecting device capable of detecting the direction of rotation of a rotating body includes first and second bridge circuits made up of magneto-resistance effect elements, a first comparator for detecting the increasing/decreasing direction of the center point voltage of the first bridge circuit, a second comparator for detecting the increasing/decreasing direction of the center point voltage of the second bridge circuit, a third comparator for detecting the difference between the center point voltage of the first bridge circuit and the center point voltage of the second bridge circuit, and logic value information deriving means for outputting '1' when the logic values of the outputs of the first comparator and the second comparator are both '1', outputting &#x201c;0&#x201d; when they are both &#x201c;0&#x201d;, and continuing to output the previous value at other times, the direction of rotation of the rotating body being determined on the basis of a combination of the outputs of the first, second and third comparators and the logic value information deriving means.

Rotation state detecting device and rotation state detecting method

In an optical information reproduction device for reproducing information from an optical disk medium on which an identification information area including first identification information shifted radially outward with respect to the center of a recording track by a specified distance and second identification information shifted radially inward with respect to the center of a recording track by a specified distance, and a user information area disposed along the center of a recording track are disposed, information is reproduced using a sum signal and a difference signal of the outputs from a split photodetector having at least two light-receiving parts disposed on opposite sides of a track tangential line. The first or second identification information signal is inverted and the direct-current component in the identification information signal and the user information signal are removed.

Optical information reproduction device and signal processing circuit used therein

An information reproduction apparatus capable of reducing or eliminating the mute period when a pickup jumps during the reproduction or when a disk is changed in an information reproduction system provided with a disk changer mechanism for selecting one disk from plural disks, or when a disk is forced to change, or an information reproduction apparatus of displaying the time information corresponding to the actual outputting time of information from the output terminal by correcting the time information included in the information read from the recording medium or determined by the recording address, or an information reproduction system provided with a disk changer mechanism capable of checking the contents of other disks during reproduction, or system of reproducing only parts of information which allow to view the contents of all disks.

Reproduction apparatus and method for successively playing back

A disc apparatus includes a readout unit, an audio signal output unit, a memory, a switch, and a controller. The readout unit reads out data from a disc wherein the data includes at least digital audio data. The audio signal output unit produces an audio signal output in accordance with the digital audio data. The memory stores the digital audio data read from the disc by the readout unit. The switch switches the digital audio data supplied to the audio signal output unit between the digital audio data stored in the memory and the digital audio data currently being read by the readout unit. Furthermore, the controller controls the readout unit and the memory so that, prior to a playback start operation, the digital audio data of a first predetermined period from a beginning of at least one program is read out by the readout unit and stored in the memory; controls the switch so that, at a beginning of the playback start operation, the audio signal output unit produces the audio signal output based on the digital audio data stored in the memory; and controls the switch so that, a second predetermined period after the start operation, the audio signal output unit produces the audio signal output based on the digital audio data currently being read out by the readout unit.

Disc apparatus for selectively outputting data from a disc and a memory

A coding apparatus for reduction and variable-length-coding of digital image data, wherein the image data is once variable-length-coded to obtain a variable length coded data. The variable length coded data is coded again to produce an amount of data. The amount of data is used to select an optimum quantization level. The variable length coded data is then coded again with the optimum quantization level to maximize a recording density of the twice coded data on a recording medium.

Coding apparatus

An information reproduction apparatus capable of reducing or eliminating the mute period when a pickup jumps during the reproduction or when a disk is changed in an information reproduction system provided with a disk changer mechanism for selecting one disk from plural disks, or when a disk is forced to change, or an information reproduction apparatus of displaying the time information corresponding to the actual outputting time of information from the output terminal by correcting the time information included in the information read from the recording medium or determined by the recording address, or an information reproduction system provided with a disk changer mechanism capable of checking the contents of other disks during reproduction, or system of reproducing only parts of information to allow the monitoring of the contents of all disks.

Information reproduction apparatus having means to control maximum delay

A digital signal which is recorded on a recording medium with being encoded is duplicated to another recording medium without being decoded. An audio signal is recorded and/or reproduced using data recorded in a TOG of the recording medium. A first data signal (2-channel audio signal) is intermittently recorded on and/or reproduced from a first area of the recording medium, and a second data signal (other 2-channel audio signal) is intermittently recorded on and/or reproduced from a second area of the recording medium during a period in which the first data signal is not recorded or reproduced.

Record/reproduction apparatus for recording/reproducing multi-channel

A coding method and apparatus is for coding a digital video signal of interlaced type. Three-dimensional (horizontal, vertical and temporal directions) blocks are constructed for each of a plurality of picture elements, orthogonal transform is performed to each of the three-dimensional blocks and coefficients are coded. Coefficients non-effected by a pseudo-moving part are weighted with a low rate, and coefficients effected by a pseudo-moving part are weighted with high rate. After the vertical positions of picture elements of odd-number fields and those of even-number fields are coincided with each other by an intra-field picture element operation, the digital video signal is formatted and three-dimensional orthogonal transform is performed.

Method and apparatus for encoding video signals in 3-D blocks without

A magnetic recording and reproducing apparatus records audio signals digitized by rotary heads (9, 10) on a magnetic tape (12), and reproduces the recorded audio signals. Clock signals and time code data are extracted from externally inputted time code signals by means of a demodulating circuit (72), and phase difference between the frame clock signals and the reference signal is detected by a phase difference detecting circuit (74). A microcomputer (23) assigns the phase difference information and the time code data to sub code packs and stores the same in the memory circuit (4). The stored phase difference information and the time code data are recorded on the magnetic tape. In reproduction, the microcomputer outputs the original time code signals responsive to the reproduced phase difference information and the time code data.

Magnetic recording and reproducing apparatus and method of recording and

A magnetic recording and reproducing apparatus records audio signals digitized by rotary heads (9, 10) on a magnetic tape (12), and reproduces the recorded audio signals. Clock signals and time code data are extracted from externally inputted time code signals by means of a demodulating circuit (72), and phase difference between the frame clock signals and the reference signal is detected by a phase difference detecting circuit (74). A microcomputer (23) assigns the phase difference information and the time code data to sub code packs and stores the same in the memory circuit (40). The stored phase difference information and the time code data are recorded on the magnetic tape. In reproduction, the microcomputer outputs and original time code signals responsive to the reproduced phase difference information and the time code data.

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Chiyoda-ku, Japan

Manabu Tsukamoto