Offset removal and spatial frequency band filtering circuitry for photoreceiver signals
US5703353A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1996 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Jan 25, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45212
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Circuitry and method for transferring signals from a photoreceiver array to computational circuitry includes parallel transfer amplifiers that receive periodic offset correction and includes DC removal amplifiers. In a first embodiment, each transfer amplifier has a differential circuit that can be switched from a reset mode to a readout mode. In the readout mode, the voltage state at the output is responsive to first and second inputs, with the second input being connected to a source of a reference voltage. In the reset mode, the inputs are both connected to the reference voltage and the output is temporarily connected to a source of a fixed reset voltage. An offset adjustment signal is generated in response to detection of a voltage difference between the reset voltage and the actual voltage state at the output after the output has been disconnected from the source of the reset voltage. A single offset circuit is used to periodically and sequentially refresh the various transfer amplifiers. In a second embodiment, spatial frequency components at both low and high frequencies are removed from the outputs of the photoreceiver array by DC removal amplifiers. Each DC removal amplifi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.