Method of and apparatus for controlling amount of electron beam in image pickup tube
US4701679A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1986 |
| Grant date | Oct 20, 1987 |
| Priority date | — |
| Expiry date | Aug 6, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/41
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an image pickup tube including a cathode, a first grid electrode disposed as a next stage of the cathode and provided with an aperture, a second grid electrode disposed as a next stage of the first grid electrode and provided with an aperture, and a photoconductive target, the first grid electrode is operated by a voltage positive with respect to the cathode. To control the amount of the electron beam of the image pickup tube, a voltage corresponding to a signal current obtained from the photoconductive target of the image pickup tube or to a return beam from the photoconductive target is applied to the second grid electrode in such a manner that a polarity of the applied voltage is opposite to a polarity of a signal charge generated on the photoconductive target.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.