Class 369/134 - With particular amplification characteristic or signal control circuitry (e.g., muting)

Subclass of Class 369 - Dynamic information storage or retrieval
Definition: Subject matter having either (a) an amplifier with a particular
No. of patents: 26
Last issue date: 05/04/2010

Number	Title	Issue Date
7710851	Optical disc apparatus A variable gain amplifier (203: VGA) for amplifying an amplitude of a signal extracted by a pickup (202), an A/D converter (204) for converting the amplified signal into digital, and an amplitude detecting circuit (206) for detecting ampl...	05/04/2010
7442913	Photocurrent amplifier circuit and optical pick-up device A photocurrent amplifier circuit is capable of selectively amplifying one or more of photocurrents which are respectively obtainable from plural receiving devices, and can be realized to have a small size. The photocurrent amplifier circuit includes: light receiving...	10/28/2008
7212815	Quality evaluation method The invention relates to a method for evaluating the quality of a signal transmission path (2) presenting non-linear distortions. According to said method a specified test signal is sent from a transmitter (1) to a receiver (3). First the level ...	05/01/2007
5589282	Magneto-optical recording medium Disclosed is a magneto-optical recording medium capable of high-density recording with low noise level and a high readout signal level. The recording medium of the invention consists of a transparent substrate 11, with a first dielectric layer 12, a readi...	12/31/1996
5084859	Multi-magazine disc player A multimagazine disc player includes an array of magazines removably stored therein each for holding a plurality of discs, and a playback means movable and positionable in alignment with one of the magazines at a time for playing back a selected one of th...	01/28/1992
5016992	Method of and apparatus for the reading of magnetically stored information A magnetic storage medium is read by incident polarized light and reflected outgoing light defining a common plane. The polarized incident light preferably has a polarization vector at 40° to 50° to this plane and at the storage medium, the magnetizatio...	05/21/1991
5008872	Optical disc reproduction apparatus which detects maximum audio signal level recorded on an optical disk An optical disc reproduction apparatus is disclosed including a device for detecting a maximum audio signal level recorded on the optical disc. A first course-search is effected of the entire optical disc to detect a first location on the optical disc in ...	04/16/1991
4962494	Optical disk playback device having automatic volume control A disc playback device capable of automatically adjusting the tone volume of a signal reproduced from a disc comprises a disc identifying circuit for identifying a disc loaded in the device, a tone volume setter for setting the tone volume of a signal rep...	10/09/1990
4847707	Rotary head type reproducing apparatus with crosstalk reduction A rotary head type reproducing apparatus having a plurality of rotary transmitters which respectively receive signals reproduced from a record bearing medium by a plurality of rotary heads is arranged to eliminate any cross-talk between the rotary transmi...	07/11/1989
4847816	Audio information reproducing apparatus An information reproducing apparatus which enables regulation of sound volume levels of signals reproduced from a multiple-audio recording medium in which one of a plurality of audio information signals may be reproduced in conjunction with video informat...	07/11/1989
4644517	Audio signal amplifier for an electromagnetic phono cartridge An audio signal amplifier for an electromagnetic transducer, comprises a transformer which has a primary winding coupled to the electromagnetic transducer for receiving an output audio signal from the electromagnetic transducer and a secondary winding for...	02/17/1987
4622660	Systems and methods for signal compensation A method for correcting higher order distortion introduced in a complex multifrequency waveform by an element which introduces signal-induced nonlinearities uses a replica of the non-linear element as a part of a high gain electronic feedback circuit betw...	11/11/1986
4547819	Magnetic pickup preamplifier A magnetic pickup which contains both resistance and stray capacitance is terminated by a negative impedance of a kind which compensates for the stray capacitance and part of the resistance, and causes a pole to be produced at a low frequency. This result...	10/15/1985
4512008	Small signal amplifying circuit for a pickup cartridge A small signal amplifying circuit suitable for use in a system such as a disc player-amplifier system in which metal contact portions such as connectors are used between a signal source and an amplifier. The small signal amplifying circuit according to th...	04/16/1985
4312060	Preamplifier for phonograph pickup The preamplifier has a first stage or section of low or unity gain, such as an emitter-follower circuit, which also isolates the preamplifier from impedance variations of the cartridge, and with a bandwidth for greater than the audio range to reproduce si...	01/19/1982
4254959	Phonograph tone arm control system A multi-function phonograph tone arm control system for a low-friction air bearing supported linear-travelling tone arm system is disclosed. Positive horizontal linear positioning is accomplished by means of an electromagnetic force producing system in wh...	03/10/1981
4247118	Record players A muting switch for co-operation with the phono sockets of a record player to short circuit the leads from the pick-up, which are connected to the phono socket, at all times except when a record is being played....	01/27/1981
4208634	Circuit for suppressing noise caused by scratches on a phonograph record A circuit for suppressing pulse-shaped interferences in an audio signal caused by scratches on a phonograph disc, comprising a signal processing section connected between an audio frequency input and an audio frequency output, comprising a noise suppresso...	06/17/1980
4135590	Noise suppressor system A noise suppressor system uses a set of parallel bandpass filters to transform an input signal into a plurality of spectral adjacent band signals. Each band signal may then be substantially attenuated (squelched) by an attenuation-control circuit when it ...	01/23/1979
4132935	Phonograph turntable control system When the user presses a touch-activated switch a first time, a first digital storage device becomes set and furnishes a platter-motor-start signal to the control electronics of the platter drive motor. If the touch-activated switch is pressed a second tim...	01/02/1979
4102536	Phonograph pickup device An improved phonograph pickup device having a pivotally mounted tone arm on which a drive coil and a sense coil are mounted and are coupled to a magnetic field. The level of current flow to the drive coil alters its position relative to the magnetic field...	07/25/1978
4035737	Low noise amplifier A low noise amplifier for amplifying a signal from a moving coil phono cartridge which comprises a plurality of pairs of complimentary first and second transistors in push-pull and each pair in parallel, with a resistance of relatively low-value in the em...	07/12/1977
4013845	Temperature compensating reproducing system A record reproducing system comprising a displacement detection type cartridge and a reproducing circuit for converting the output signal of the displacement detection type cartridge into audio signals. Either the displacement detection type cartridge or ...	03/22/1977
3952170	Miniature apparatus for reproducing sound from a stationary record Miniature apparatus for reproducing sound from a stationary record which comprises a base and a main shaft mounted on the base. A disc-like member is rotatably mounted on the main shaft and means is carried by the base for rotating the disc-like member. A...	04/20/1976
3940698	Muting circuit A muting circuit comprises, substantially, a gate circuit for passing or not passing input signals and a circuit for forming a control signal for controlling the gating operation of the gate circuit. The control signal forming circuit has a circuit for de...	02/24/1976
3937902	Cartridge muting circuit A muting circuit is provided for a phonograph record amplifier employing a semi-conductor cartridge wherein the cartridge has a shorting switch operative during the changing cycle wherein the amplifier associated with the cartridge is deactivated during t...	02/10/1976

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Class 369/134 - With particular amplification characteristic or signal control circuitry (e.g., muting)