Gamma correction circuit
US4480268A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | Jun 2, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/202
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A gamma correction circuit is provided with a first circuit including a first linear element and a first non-linear element connected in series in the above order and a second circuit including a second non-linear element and a second linear element connected in series in the above order. A first connection point is located between the first linear element and the second non-linear element and a second connection point is located between the first non-linear element and the second linear element. A current source for converting a video signal voltage into a current output is connected to the second connection point. Two common collector (or common drain) transistors have their collectors (or their drains) connected to a power supply line. The input terminals of these transistors are connected to the connection point between the first linear element and the first non-linear element and to the connection point between the second non-linear element and the second linear element respectively, and the output terminals are connected to each other through a resistor. In order to decrease the junction capacitance of the transistors as the video signal voltage level increases, a voltage reg…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.