| Patent Number |
Title Of Patent |
Date Issued |
| RE29171 |
Multi-directional sound system |
April 5, 1977 |
| A multi-directional sound system for use in the manufacture of matrix four channel stereophono discs comprises an encoder including a plurality of phase shifters for shifting the phases of a plurality of directional input signals from discrete sound sources by angles corresponding to the |
| D255683 |
Combined amplifier and tuner |
July 1, 1980 |
|
| D254616 |
Head phone |
April 1, 1980 |
|
| D253289 |
Control knob for audio apparatus |
October 30, 1979 |
|
| D253109 |
Speaker box with removable grill |
October 9, 1979 |
|
| D252393 |
Record player |
July 17, 1979 |
|
| D251003 |
Tone arm |
February 6, 1979 |
|
| D250759 |
Tape deck |
January 9, 1979 |
|
| D250535 |
Combined tuner and amplifier |
December 12, 1978 |
|
| D250534 |
Combined tuner and amplifier |
December 12, 1978 |
|
| D250472 |
Tape deck |
December 5, 1978 |
|
| D249946 |
Amplifier |
October 17, 1978 |
|
| D249146 |
Tuner |
August 29, 1978 |
|
| D249143 |
Record player |
August 29, 1978 |
|
| D248471 |
Speaker cabinet |
July 11, 1978 |
|
| D247749 |
Tuner |
April 18, 1978 |
|
| D247488 |
Record player |
March 14, 1978 |
|
| D246519 |
Head phone |
November 29, 1977 |
|
| D243794 |
Combined amplifier and tuner |
March 22, 1977 |
|
| D243255 |
Combined amplifier and tuner |
February 1, 1977 |
|
| D242638 |
Amplifier |
December 7, 1976 |
|
| D242637 |
Amplifier |
December 7, 1976 |
|
| D242636 |
Amplifier |
December 7, 1976 |
|
| 5206466 |
Diaphragm for speaker |
April 27, 1993 |
| A speaker diaphragm includes a combined fiber paper made with crushed silk chips and a crushed bast fiber. In the preferred embodiment, the bast fiber is a natural Manila hemp fiber. The silk fiber contributes vibration damping to the diaphragm while the bast fiber contributes strength a |
| 4759038 |
PCM transmission system |
July 19, 1988 |
| A PCM difference data is obtained from an original data, and an absolute data having a lower bit number than the original data is obtained at every data block, each data block comprising a plurality of the difference data. The transmission data includes the difference data and absolute d |
| 4716590 |
AM stereo transmission method and apparatus |
December 29, 1987 |
| This invention discloses an AM stereo transmission method characterized in that when left and right audio signals L and R are transmitted as an AM stereo signal which is represented by S=A cos(.omega.t+.phi.) wherein A denotes an amplitude, .omega. a carrier angular frequency and .phi. a |
| 4633483 |
Near-instantaneous companding PCM involving accumulation of less significant bits removed from o |
December 30, 1986 |
| A data transmission system combines a near-instantaneous companding system with PCM or DPCM transmission data. In the transmitting side, lower bits are removed from an original data, to form transmission data and are accumulated in an accumulator. When a carry is caused as a result of su |
| 4626936 |
Relative velocity control device for magnetic recording and reproducing apparatus |
December 2, 1986 |
| The present invention discloses a relative velocity control device which enables to generate constant relative velocity between a head and a tape in a magnetic recording and reproducing system with a rotating head. When the tape running speed and direction are given at input terminals, t |
| 4585952 |
Digital waveform shaping circuit |
April 29, 1986 |
| The present invention provides a digital signal waveform shaping circuit for reproducing a digital signal recorded on a recording medium. The waveform shaping circuit includes at least one comparator for receiving an input signal and a delay circuit connected to the output of the compara |
| 4580278 |
Read clock producing system |
April 1, 1986 |
| In a read clock producing system for generating a read clock signal which is used for extracting a digital information portion of a digital coded signal, the system comprises means for delaying a pulse obtained by comparing data with a certain threshold level, means for generating a |
| 4546394 |
Signal reconstruction circuit for digital signals |
October 8, 1985 |
| A digital signal reconstruction circuit includes a reproduction means for reading a digital data signal recorded on a recording medium, signal derivation means for deriving a plurality of shifted signals produced by sequentially shifting the read digital data, arithmetic means, comprisin |
| 4517528 |
Amplifier circuit driven by ground isolated power supply |
May 14, 1985 |
| Disclosed is an amplifier wherein, in order to prevent the mixing of hum and other noise from the ground potential of the amplifier, the driving power supply circuit of the amplifier is separated from the ground potential into a floating state. In addition, the overall capacity of the |
| 4475185 |
Record player with vibration cancellation mechanism |
October 2, 1984 |
| In a record player of the direct drive system wherein a turntable and a motor for driving the turntable are directly coupled; a record player characterized in that a cancellation mechanism is disposed coaxially with the driving motor, said cancellation mechanism performing a reciprocatin |
| 4425638 |
Dual turntable record player with torque cancellation |
January 10, 1984 |
| A record player wherein a second turntable and motor which are respectively equivalent to an ordinary turntable and motor are additionally disposed, and both the motors are driven and controlled so as to cancel their torques each other, thereby to eliminate a cross modulation distortion |
| 4401951 |
Bias circuit for use in a single-ended push-pull circuit |
August 30, 1983 |
| A bias circuit for use in the single-ended push-pull circuit has NPN and PNP transistors whose emitters are connected to each other and whose collectors provide a bias voltage, diodes and resistance elements. On the operating side, the diode gives a reference voltage and the resistance |
| 4367442 |
Distortion correction circuit for a power amplifier |
January 4, 1983 |
| An amplifying device comprising a pre-amplifier, a first high power amplifier of a relatively bad lineality for amplifying the outputs of the pre-amplifier, a first impedance element for applying the outputs of the first amplifier to a load, a negative feedback circuit for feeding back |
| 4229705 |
Differential amplifiers |
October 21, 1980 |
| A differential amplifier able to produce differential-mode output signals different from one another in DC voltage level, is formed by connecting a pair of NPN transistors and another pair of PNP transistors so that the emitter electrodes of these four transistors are coupled to one anot |
| 4216517 |
Protection circuit for power amplifier |
August 5, 1980 |
| Disclosed herein is a protection circuit for a power amplifier. The protection circuit comprises a current detecting section for detecting a level of a load current of the power amplifier, a voltage detecting section for detecting a level of a load voltage across a load, an AND-gate |
| 4193076 |
Coupling an outer antenna with a radio receiver having a bar antenna |
March 11, 1980 |
| Coupling an outer antenna with a radio receiver having a bar antenna is achieved by connecting the outer antenna to a coupling coil which is able to be removably mounted on a bar core of the bar antenna and by mounting the coupling coil on the bar core with such an orientation of the cou |
| 4177360 |
Moving magnet type pickup cartridge |
December 4, 1979 |
| A pickup cartridge is disclosed, which comprises a cantilever having one end provided with a stylus and the other end provided with an armature magnetized in the axial direction thereof, a yoke having at least three leg portions each having an end face, the end faces being faced to a |
| 4167650 |
Stereo signal demodulating circuits |
September 11, 1979 |
| A stereo signal demodulating circuit of a switching type is provided with a differential amplifier to obtain difference signals between two output signals from the switching circuit. The difference signals from the differential amplifier are added to the stereo composite signal to obtain |
| 4158795 |
Brushless DC motors |
June 19, 1979 |
| A brushless DC motor capable of change of rotational direction is disclosed. The feed of a high-frequency voltage signal to switching elements is sequentially changed to orderly excite stator windings by the outputs from rotor angular position detectors so that the rotor is rotated i |
| 4144502 |
Negative feedback amplifiers of PWM-type |
March 13, 1979 |
| A negative feedback operation of a PWM-type amplifier is stabilized by the use of a resistor. The input signal is voltage-compared with the triangular wave of a higher frequency than the input signal to form a PWM-signal, which is, in turn, power amplified and is provided to a load a |
| 4144463 |
Stabilized DC power supply devices for providing a plurality of DC power outputs which are selec |
March 13, 1979 |
| A stabilized DC power outputs supply devices for providing a plurality of DC power outputs which are selectively consumed, is provided by use of a single power control circuit. A plurality of DC power outputs are taken out from the single power control circuit through rectifier circuits |
| 4139075 |
Loudspeaker device |
February 13, 1979 |
| A loudspeaker device comprises a bass reflexing duct formed on an enclosure on which the loudspeaker unit is provided, a passive radiator provided on the enclosure; an acoustic impedance body provided between at least one of the duct and passive radiator and the loudspeaker unit, so that |
| 4135164 |
Synchronous generating circuit devices with two phase-locked loops and feedback around both |
January 16, 1979 |
| A circuit device for generating a synchronous signal in synchronism with a steady wave component of an input signal and including a first phase-locked loop using the input signal as a reference signal, a second phase-locked loop using an output signal of a voltage controlled oscillat |
| 4135162 |
Power amplifier circuits |
January 16, 1979 |
| A power amplifier circuit having a differential amplifier at an input stage and a following complementary symmetry circuit which is driven by a pair of opposite phase output signals of the differential amplifier as a push-pull circuit. One of the pair output signals is directly applied t |
| 4118605 |
Coil mount structure |
October 3, 1978 |
| A coil mount structure for use in a loudspeaker of moving coil type is disclosed which comprises a generally cylindrical member at around one end portion of which a center peripheral portion of a diaphragm and an inner peripheral edge portion of a damper are removably fixed and at around |
| 4117406 |
Muting arrangement for AM synchronous detector using a PLL circuit |
September 26, 1978 |
| The output voltage of an AM synchronous detector is compared with a reference potential level by a voltage comparator. A muting device connected with the output of the detector is controlled by a control circuit connected with the comparator. Through this control circuit, the detecto |
| 4105946 |
Frequency synthesizer with phase locked loop and counter |
August 8, 1978 |
| A frequency synthesizer including a phase-locked loop (PLL) is provided which does not use any variable frequency divider. The output of a reference frequency oscillator is applied to a phase comparator in the PLL through a monostable multivibrator. The oscillating frequency of a voltage |
