Sharp Kabushiki Kaisha Corporation

Computer Basic Technology Research Association

Computer Basic Technology Research Assoc.

Yoshiki Nishioka

Hiroyuki Iwahashi

Nobuyuki Horie

Mitsuhiro Hakaridani

Toshihiro Yamanaka

Toshihisa Deguchi

Syoichi Yasuda

Shigemi Maeda

Noriaki Sakamoto

Shozou Kobayashi

Teruki Sugiura

Yoshio Yuki

Takeshi Yamaguchi

Chuji Suzuki

Toshiaki Morita

Daiji Yamane

Fusao Makino

Shozo Kobayashi

Hisashi Minami

Toshiaki Fujikawa

Aisaku Taguchi

Hironari Takatori

Noriaki Sakamoro

Toru Ueda

An apparatus for operating a magneto-optic medium includes a magnetic biasing field developing device for developing a magnetic biasing field which is applied to the magneto-optic medium when the magneto-optic medium erases or records data. Additionally, a neutral-position controller is provided for positioning permanent magnets of the magnetic biasing field developing device in a neutral position with respect to the medium when the magnetic biasing field developing device is switched off. Thereby, the neutral-position controller maintains the medium at the neutral position with respect to the permanent magnets until the magnetic biasing developing device is switched on and the permanent magnets are placed in a field applying position.

Apparatus for developing a magnetic field which maintains a neutral

A transducer access control system for use in a disk recording/reproducing apparatus for moving a transducer a required distance from its present position over a disk in the radial direction thereof, includes a linear motor for driving the transducer, a circuit for generating a distance signal indicative of the required distance for moving the transducer, and a calculator for calculating a half distance which is a half of the required distance. To move the transducer for the required distance D, the linear motor is operated at the velocity controlled in accordance with a reference velocity signal produced from a reference velocity generator. The reference velocity is determined such that, the reference velocity is maintained at a predetermined value during the movement of the transducer in the first half of the required distance, and gradually decreases during the movement of the transducer in the second half of the required distance.

Transducer access control system

A signal processing device comprises a comparator, a first reference signal generating unit, a second reference signal generating unit and reference signal controller and switch which is switched when the data head data of the input signal is detected by the controller. In the case when the content of the input signal is a clock producing data, the reference signal generated in a rapid process of the first reference signal generating unit is entered in the comparator, and in the case when the content of the input signal is a reproduction data, the reference signal generated in a slow process of the second reference signal generating unit is entered in the comparator so as to be compared with the input signal.

Signal processing device for analogue to digital conversion

A device for controlling an access operation of an information recording and reproducing device to a target position for rough access in a disk-shaped recording medium prior to a precision access to a final target position, including a head carried by an actuator, a scale, a counter, a comparator, a timer, and a controller. The scale emits pulses while the head is traveling. The counter counts the pulses and then provide the count to the comparator, which calculates a difference between the count and an access distance to be traveled for rough access and then compares the difference with a value which is determined in advance in consideration of a tolerable error. The comparison result is input into the controller. If the comparison result received when the timer finishes measuring the specified time indicates that the difference between the access distance and the count falls within the range of the predetermined value, the controller decides that the actual rough access operation has been normally finished as desired, thereby decreasing a wrong judgement with respect to finish of the rough access irrespective of a value counted by the counter.

Device for controlling an access operation of an information recording

An auto-correlation unit for pattern recognition to obtain auto-correlation functions as for sampled signals is disclosed N pieces of sample values X.sub.n (n=0 to N-1)are extracted from a series of the sample values expressed with an accuracy of optional multi-bits and the auto-correlation coefficients of these N pieces of the sample values obtained. The sum of sample values X.sub.n and X.sub.n-.tau. (.tau.=0 to P) are calculated. The squared value (X.sub.n +X.sub.n-.tau.).sup.2 of the added results is previously memorized in a ROM while being addressed by the resultant sum. The auto-correlation coefficients are available by feeding the output (X.sub.n +X.sub.n-.tau.).sup.2 of the ROM and executing calculation as defined by the following equation: ##EQU1##

Auto-correlation circuit for use in pattern recognition

A disk recording checking method in which recording is performed on a disk having radially different recording tracks each divided circumferentially into a plurality of sectors. The method employs a continuous writing device for continuously writing data onto a predetermined number of the sectors, and a continuous checking device for checking the data, while continuously reading the data from the predetermined number of the sectors. The method utilized checks both the number of errors in each code sequence and the total number of errors in each sector to determine if the data in the sector is valid.

Disk recording checking method for determining if a disk is defective by

A disk recording method in which recording is performed on a disklike recording medium having a radially coaxial or spiral recording track that is divided into a predetermined plural number of recording sectors each acting as a recording unit. A predetermined number of dedicated sectors are provided at a rear portion of the recording track so that the contents that are recorded in defective sectors of the recording sectors are alternatively assigned to the dedicated sectors.

Method of disk recording using alternative recording tracks

In a speech recognition system, logarithmic amplifiers avoid low level signal or noise problems by clamping all signals below an input threshold to a constant output level.

Speech recognition system with generation of logarithmic values of

A correlation function computing device capable of computing a selfcorrelation function or the like is constructed to comprise a window function memorizing circuit, an A/D converting circuit for converting time series of a voice signal into digital values, a multiplier for calculating products of the window functions and the digitalized time series of the voice signal and also products required for the computation of the correlation function, a memory circuit for storing the products of the window functions and the digitalized time series of the voice signal delivered from the multiplier, a selector circuit for transferring data supplied to the multiplier, an adder for obtaining a product-sum in a divided manner, a memory circuit of a first-in and first-out type for storing the product-sum dividedly obtained in the adder, and a control circuit for controlling all of the aforementioned circuits.

Correlation function computing device

A floppy disk driving circuit comprises a memory circuit for storing a plurality of items of delay time of a pair of erase heads from the switching-ON and the switching-OFF of a read/write head for all the tracks of a floppy disk, a control circuit responsive to the memory circuit for controlling ON- and OFF-delay timing of the pair of erase heads based on the plurality of items of delay timing. The plurality of items of suitable timing are previously calculated in connection with the respective tracks of the disk and stored within the memory circuit.

Floppy disk driving with suitable on-delay and off-delay timing

In a speech analysis/recognition system, the input utterance is also directly registered (stored) for later readout verification of correct start and end control signals.

Speech recognition system

Speech recognition executes the final matching operation for each characteristic pattern according to the preliminarily selected order prior to the final matching, where any further calculation in reference to such a characteristic pattern is not executed after a specific condition has been satisfied during the matching calculation, and as result, calculation requirements can be drastically minimized so that the speech recognition can eventually be implemented at higher speed and yet under a sharply reduced cost.

Speech recognition with preliminary matching

In a speech recognition system, similarity calculations between speech feature patterns are reduced by stopping similarity calculations for any one reference pattern when a frame in the pattern fails to exceed a corresponding similarity threshold.

Method of speech recognition

Speech recognition using self-correlation (auto-correlation) parameters and time normalization is improved by first making a preliminary decision using lower-order (zeroth to third) self-correlation coefficients derived from the self-correlation function of order m: ##EQU1## where .phi.(0) is the power, .phi.(1) is the linear or first order coefficient, and so on.

Recognition of speech or speech-like sounds

Handwritten character identification employs two constraining dots and radius vectors extending out from each of these dots in a manner to identify large quantities of numeral characters by determining which of these radius vectors are crossed, whereby these crossings sample a predetermined segmented character font pattern to designate the presence and absence of the respective segments. In particular, the number of the radius vectors concerning the horizontally-oriented segments is increased to minimize a possibility of error while leaving the two constraining dots to keep mild restrictions on the size and form of the characters to be handwritten and identified.

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Tenri, Japan

Yoshiki Nishioka