Focus detecting photoelectric device and focus detecting system
US4496834A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1982 |
| Grant date | Jan 29, 1985 |
| Priority date | — |
| Expiry date | Apr 6, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/191
Abstract
A focus detecting photoelectric device includes a plurality of photodiodes each formed by an amorphous silicon layer sandwiched between transparent and non-transparent electrodes. The photodiodes are provided in pairs and are aligned in an array and deposited on a glass plate such that the transparent electrode is directly mounted on the glass plate. The photodiodes in a pair are located closely adjacent to, but in a spaced relation with, each other and are electrically connected in series to each other. An image formed on the photodiodes in a pair effects the generation of photocurrent from the photodiodes such that the photocurrents from both photodiodes are approximately the same when the image is out of focus, and they vary from each other as the image becomes sharp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.