Analog to digital video converter
US5874909A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1997 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Feb 13, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/672
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An integrated analog to digital interface subsystem for imaging applications includes digital global and digital pixel by pixel offset correction and scaling. The integrated interface 2 includes 3 DAC's 2c1-2c3 that are used to do a rough offset cancellation on the three analog input signals (RGB) in the analog domain. A triple sample/hold circuit 2a samples the RGB signals simultaneously, multiplexes the data and passes the three signals on the ADC 2b sequentially (at about 3 times the data rate). The sample/hold circuit 2a has the capability to operate in fully differential as well as single ended input mode, and can perform correlated double sampling if needed. A high resolution ADC 2b converts the 3 multiplexed signals from simple/hold circuit 2a. A first digital offset correction circuit 2f restores the level of the RGB signals in the digital domain on a pixel by pixel basis. A first digital gain correction circuit 2g compensates for sensitivity variations of the RGB sensors in the digital domain on a pixel by pixel basis. A second digital offset correction circuit 2h restores the overall DC level of the RGB signals in the digital domain. A second digital gain correction circu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.