Threshold signal circuitry for scanning apparatus
US3934136A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1974 |
| Grant date | Jan 20, 1976 |
| Priority date | — |
| Expiry date | May 6, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/16576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Circuitry providing a scanning threshold for a scanning apparatus in response to the output of a photomultiplier of the apparatus produced during a threshold determining scan of the field uses a first memory circuit to store a signal level indicative of the maximum light intensity sensed by the photomultiplier with a second memory circuit provided to store a signal level indicative of the minimum light intensity sensed. A threshold circuit connects with the stored signals to provide a threshold signal intermediate the two stored signal levels. An inhibiting circuit may be provided to prevent the second memory circuit from responding to signals below a predetermined level. Inhibiting circuitry and memory deletion circuitry are used to condition the memories prior to and immediately following a threshold determining scan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.