Famous Patents
Felix Hoffmann, a German chemist, was searching for something to relieve his father's arthritis. In doing so, he "rediscovered" acetylsalicylic acid and in 1900, patented a stable process for developing it. Hence, we have aspirin.
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 4891839 | Signal re-distribution, decoding and processing in accordance with amplitude, phase and other characteristics Decoding apparatus is disclosed providing desirable multichannel separation among various signals received in a channel pair and distinguished by relative phase and amplitude, including re-distribution of output vs. input signal nulls or positions on the ... | 01/02/1990 |
| 4862502 | Sound reproduction A directionality enhancement system for converting encoded stereo signals on input channels A and B into four signals on left, center, right and surround output channels.... | 08/29/1989 |
| 4850021 | Method and a circuit for decoding four channel signals which are coded in a matrix and available in the form of a two-channel signal By a method and a circuit for the purpose of decoding four-channel signals coded in a matrix and available in the form of a two-channel signal, whereby in each channel an automatic control of the amplification will take place by means of an output amplifi... | 07/18/1989 |
| 4807217 | Multi-channel stereo reproducing apparatus The present invention provides a multi-channel stereo reproducing apparatus which can reproduce a recording medium such as an audio disc or the like in which in order that users can enjoy screen musics or the like reproduced at, for example, a concert hal... | 02/21/1989 |
| 4799260 | Variable matrix decoder The decoder of this invention decodes at least two channel signals in a directional information system where at least four input signals containing directional information have been encoded into the two or more channel signals. The decoder generates a fir... | 01/17/1989 |
| 4704728 | Signal re-distribution, decoding and processing in accordance with amplitude, phase, and other characteristics Decoding apparatus is disclosed providing desirable multichannel separation among various signals received in a channel pair and distinguished by relative phase and amplitude, including re-distribution of output vs. input signal nulls or positions on the ... | 11/03/1987 |
| 4696036 | Directional enhancement circuit A system for receiving a plurality of audio input signals encoded with sound directions drives a plurality of loudspeakers which are physically arranged to generate apparent sound images in relation to encoded sound directions. The encoded input signals a... | 09/22/1987 |
| 4532647 | Automatic dimension control for a directional enhancement system A directional enhancement system for quadrophonic sound systems wherein the improvement comprises an automatic dimension control. The automatic dimension control utilizes a plurality of limiting devices, each of which has an input terminal, an output term... | 07/30/1985 |
| 4525855 | Variable rate and variable limit dimension controls for a directional enhancement system The disclosed invention relates to directional enhancement systems and provides apparatus for enhancing the directional content of information contained in a plurality of composite signals derived from preceding decoding apparatus of the system. The appar... | 06/25/1985 |
| 4414430 | Decoders for feeding irregular loudspeaker arrays A decoder is provided for feeding an irregular array of m (being three or more) pairs of diametrically opposite loudspeakers, each loudspeaker being disposed at an equal distance r from a common reference point. The decoder incorporates a WXY circuit 10 f... | 11/08/1983 |
| 4021612 | Decoder apparatus applicable to matrix 4-channel systems of different types This invention discloses a control circuit to be used in a decoder apparatus applicable to matrix 4-channel systems of different types. The control circuit is adapted to control, according to the type of composite signals to be decoded by the decoder appa... | 05/03/1977 |
| 4018992 | Decoder for quadraphonic playback Quadraphonically encoded left end right signals are fed to separate left and right signal phase shifters the outputs of which are fed to three variable gain amplifiers for each of the four corner loudspeakers of a quadraphonic playback system and also to ... | 04/19/1977 |
| 3982069 | Decoding apparatus for use in matrix four channel systems of a plurality of types A four channel decoding apparatus comprises means to form signals LT+RT, LT-RT, +jLT+RT; LT+RT, LT-RT; and LT+jRT, LT-jRT, for example, from composite signals LT and RT depending upon the type of the matrix four channel systems and means for additively an... | 09/21/1976 |
| 3967063 | Logic for matrix systems for reproducing quadraphonic sound Apparatus for decoding four separate channels of information transmitted on two channels or transduced from a medium having only two separate tracks and presenting it on four loudspeakers to give the listener the illusion of sound coming from a correspond... | 06/29/1976 |
| 3959590 | Stereophonic sound system A stereophonic sound system where a plurality of audio signals produced at the program source are encoded to two channels for recording or transmission, and then decoded at playback to produce a plurality of acoustical signals corresponding to those recei... | 05/25/1976 |
| 3952157 | Matrix four-channel decoding system A matrix four-channel decoding system wherein the mixing coefficients or mixing ratios of left and right composite signals of medium frequency range are continuously changed in accordance with the level conditions of directional audio input signals contai... | 04/20/1976 |
| 3947637 | Signal composing circuit A signal composing circuit suitable for a decoder device of a 4-channel matrix stereophonic system comprises two types of circuit units, one being a differential type circuit in which the common emitters are connected to ground through constant current me... | 03/30/1976 |
| 3943287 | Apparatus and method for decoding four channel sound An apparatus and method for decoding four individual audio signals to the extent they are contained in first and second composite signals. The first composite signal contains the first individual audio signal in dominant proportion and two other individua... | 03/09/1976 |
| 3943286 | Variable gain control circuit A variable gain control circuit comprising a signal transmitting path having an input terminal supplied with an input signal and an output terminal delivering therefrom a gain controlled output signal, a variable impedance device having first, second and ... | 03/09/1976 |
| 3937885 | Control circuit for a matrixed four channel audio reproducing system A gain controlled audio amplifier for each channel which includes a differential to single ended converter fed by a differential amplifier, the common emitters of which are coupled to balance and volume control circuitry for controlling the amount of curr... | 02/10/1976 |
| 3934086 | Matrix four-channel decoding system To the output side of a matrix four-channel decoder for producing four outputs while controlling the mixing coefficients of left and right composite signals in accordance with the level or instantaneous amplitude relationship between directional audio inp... | 01/20/1976 |
