Fast current-mode analog circuit for converting video data signals between color space formats
US5708481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1996 |
| Grant date | Jan 13, 1998 |
| Priority date | — |
| Expiry date | Jul 31, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/67
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color space converter is implemented using current mode analog circuitry to efficiently transform video data from a YC.sub.b C.sub.r format to an RGB format in order to allow the display of video signals on a color monitor. The analog current-mode circuitry is implemented in an integrated circuit that will operate at high clock rates and can be integrated in a small die area so as to reduce its cost. The color space converter includes Y, C.sub.b and C.sub.r current-mode conversion circuits to compute Y, C.sub.b and C.sub.r contributions to the G, R and B signals, and current-mode adders that add those contributions to the G, R and B signals to generate the G, R and B signals. Each conversion circuit includes (A) a respective folded cascode structure having an input coupled to a respective analog Y, C.sub.b or C.sub.r signal, each conversion circuit generating a respective Y, C.sub.b or C.sub.r current output; (B) at least one respective current mirror that generates from the Y, C.sub.b or C.sub.r current output an unadjusted Y, C.sub.b or C.sub.r contribution to at least one of the G, R and B signals, and (C) at least one current adder for subtracting respective offset currents f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.