Light measuring device
US4465370A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1981 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Jun 30, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A light measuring device includes one or more photodiodes, which generate current in relation to the received light, and at least one capacitor for integrating the generated current. The amount of charge stored in the at least one capacitor at the completion of the integration is roughly detected by the number of capacitors used and/or the voltage across the capacitor. A current source capable of producing different levels of current in accordance with the detected amount of charge is provided for changing the amount of charge stored in the at least one capacitor. The time needed to change the amount of charge stored in the at least one capacitor is measured so as to obtain the value of total amount of the change in the charge stored in the at least one capacitor and to thus obtain the value of the received amount of light intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.