Abstract: A laser waveform generation function is provided in a laser driving waveform generator 2 near a laser 3. A recording clock generator 9 is included in the laser driving waveform generator 2 to generate a clock with a frequency higher than that of a synchronizing clock 202. This allows a recording laser current (waveform) to be generated without transmission of a high frequency signal from the modulator 6. Further, because the synchronizing clock 202 is stopped upon a reproduction operation including reproduction operation in an ID unit, undesired effects on a reproduction operation such as ID reproduction can be reduced. Because the response speed of the recording clock generator 9 can be changed, a high precision clock can be generated. Thus, a high-precision recording laser current (waveform) can be generated.

Abstract: An information recording/reproducing apparatus which can record and reproduce information data into and from various kinds of recording mediums has a laser driver which enables recording strategy control for each kind of recording medium. The laser driver receives an NRZ binary signal and a clock signal synchronized with the NRZ binary signal from a modulation circuit, and generates a recording current signal corresponding to the NRZ binary signal. The laser driver includes a PLL circuit disposed in the laser driver which oscillates at a recording frequency, and an unlock detection circuit which detects an oscillating condition of the PLL circuit and outputs a detection signal indicative of the oscillating condition of the PLL. A recording operation of the information recording/reproducing apparatus is controlled based on the detection signal outputted from the unlock detection circuit.

Abstract: A laser drive integrated circuit and an optical disk apparatus using the laser drive integrated circuit for forming high-density marks. The optical disk apparatus includes a drive waveform information storage unit for storing at least one information of a drive waveform for driving a laser diode in response to a binary recording signal to be recorded in a recording medium, and a drive waveform decoder for decoding the drive waveform based on the information stored in the drive waveform information storage unit. A recording strategy can be changed in accordance with variations and fluctuations of recording media or characteristics of the recording media, while at the same time reducing a number of signal lines in flexible wiring and alleviating effects of signal distortion in the signal lines.

Abstract: A pressure control apparatus and method are provided for controlling hydraulic clutches of a backward and forward drive switching device mounted in a transmission of a working vehicle such as a tractor. When a backward and forward drive switching shuttle lever is operated, a current supplied to an electromagnetic proportional valve is controlled to gradually increase the pressure for a hydraulic clutch corresponding to a direction of movement. When a propelling drive connecting and disconnecting clutch pedal is operated, the pressure for that hydraulic clutch is controlled through the electromagnetic proportion valve, based on a depressed position of the pedal. When the operator switches the shuttle lever from forward to backward or vice versa, a microcomputer causes the shuttle control current to rise at a point of time of start of a clutch engaging operation of the clutch pedal.

Abstract: During a shifting operation to slide a shift gear of an auxiliary change speed device, clutches of a backward and forward drive switching device acting also as a propelling clutch and of a main change speed device are automatically disengaged to place these devices in neutral state. After the shift gear is switched to a high-speed position or low-speed position, the clutches of the main change speed device are automatically engaged to return the main change speed device to a transmitting state. After the main change speed device returns to the transmitting state, the clutches of the backward and forward drive switching device are automatically engaged to return the backward and forward drive switching device to a transmitting state.

Abstract: A drive transmission system for a working vehicle for transmitting power of an engine to running devices through a main clutch, a main change speed device and an auxiliary change speed device is disclosed. The main change speed device includes a first group of hydraulic clutches and a group of control valves for operating these clutches. The auxiliary change speed device includes a second group of hydraulic clutches and control valves for operating these clutches. Pressure oil is supplied to selected clutches of the first and second groups of hydraulic clutches to obtain the desired speed.

Abstract: An apparatus suitable for measuring coordinate positions of points in a wide range of coordinate read area on a plane. The apparatus includes a cursor, a cursor drive circuit for supplying an alternate current signal to the cursor, a coordinate read device for detecting an induced magnetic field generated by a current flowing through the cursor and for generating a plurality of induced voltages, a change-over circuit connected to the coordinate read device, an induced voltage detect circuit connected to the change-over circuit for detecting a peak voltage of the plurality of induced voltages generated by the coordinate read device, a coordinate position detect circuit for effecting a calculation of a position of the cursor from the plurality of the peak voltages detected, and a control circuit for controlling the cursor drive circuit, the change-over circuit, the induced voltage detect circuit, and the coordinate detect circuit.

Abstract: A speech synthesizer is disclosed with the capability of stretching and compressing the speech time base without changing the pitch of the synthesized speech. One frame of speech is represented during a given time base by LPC parameters which are sampled a constant number of times per frame and stored in memory. Speech is synthesized by fetching each of the stored LPC parameters for each frame and subjecting the parameters to interpolation, synthesizing the interpolated parameters and converting the synthesized parameters to analog format. A decrease in the speed of the reproduced speech is produced by lengthening the time interval of interpolation between the fetching of each of the stored LPC parameters which have been previously stored for each frame. An increase in the speed of the reproduced speech is produced by decreasing the time interval of interpolation between the fetching of each of the stored LPC parameters which have been previously stored in each frame.

Abstract: An alarm device for a vehicle comprises sensors for detecting abnormal states of the vehicle, a logic circuit for receiving the outputs of the sensors and producing one or more alarm speech designation signals and an alarm speech generator responsive to the alarm designation signal. The logic circuit includes a priority circuit for determining the order of precedence of the abnormal states represented by the detection signals on the basis of the degree of emergency, so that the alarm speech is concerned with the most emergent alarm when two or more abnormal states are detected simultaneously. The logic circuit may further include a switch circuit for disabling at least one of the detection signals so that a vehicle driver having taken notice of particular alarms is not disturbed by excessive alarming.

Abstract: A speech analyzer for extracting spectrum information and pitch information from natural speech wherein an accuracy of pitch extraction is enhanced by sampling pitch at a sampling frequency which is higher than a sampling frequency for analyzing the spectrum information.

Abstract: This PARCOR-type speech synthesizer replaces a ten-stage lattice type filter with a pipeline multiplier and feedback loop, and provides a loss circuit (for bandwidth broadening) using subtraction circuits for multiplication.

Abstract: Three sets of light receivers are arranged on the turn table of a phonograph record player. The light radiated on the turn table is received and introduced to light receiving elements for conversion into a pulse signal. When a 30-cm record is placed on the turn table, the three sets of light receivers are all converted and fail to produce a pluse signal. When a 25-cm record is placed on the turn table, the first set of light receivers are exposed; while when a 17-cm record is placed on the turn table, the first and second sets of light receivers are exposed. The number of pulses produced from the light receiving elements is counted, thus determining the size of the record placed on the turn table.

Abstract: There is disclosed an electronic switchover circuit which can eliminate noises caused when two or more input signals are electronically selected to deliver out one of these input signals. A plurality of differential amplifier sets each having first and second transistors of which the first transistor receives the input signal are provided for the circuit, and a control voltage is applied to the control terminal of a constant current source to enable only one of the plurality of differential amplifier sets to thereby deliver out the input signal applied to the one differential amplifier set while disabling the remaining differential amplifier set. The base of the first transistor of the respective differential amplifier sets is connected with a third transistor which operates in the opposite phase relationship to the associated differential amplifier set, whereby base potentials of the first transistors of the differential amplifier sets which are disabled can be kept constant.

Abstract: A variable impedance circuit comprises a differential current circuit having a diode and a first transistor connected so as to operate differentially with respect to each other, and a current control circuit for controlling current flowing through the differential current circuit, whereby variation of the operative resistance of the differential current circuit causes variation of impedance thereof. The current control circuit comprises a second transistor having a collector connected with the differential connection of the differential current circuit, and an emitter grounded via a resistor, and a third transistor having a base applied with a control voltage and an emitter connected with the emitter of the second transistor. A fourth transistor is also provided having a collector connected to the base of the second transistor, a base connected to the collector of the third transistor and an emitter applied with source voltage independently from the current flowing through the differential current circuit.

Abstract: A variable impedance circuit comprises an amplifier with a high input impedance and a high output impedance whose gain is variable in response to a control voltage, an emitter-follower transistor, and an impedance element adapted to feedback an output signal to an input terminal of the amplifier. The input terminal of the amplifier and the input terminal of the emitter-follower transistor are connected in common. The emitter-follower transistor has its output terminal connected in series with the output terminal of the amplifier through a load resistor. An impedance of the amplifier as viewed from its input terminal is multiplied by Miller effect and varied in value by the control signal to a great extent.