Optical module and optical encoder comprising a dummy light receiving device formed between a light receiving device and a through hole in a sensor substrate
US11112279B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2020 |
| Grant date | Sep 7, 2021 |
| Priority date | — |
| Expiry date | May 27, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/34715
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical module includes a fixed substrate, and a sensor substrate secured to the fixed substrate and having a through-hole formed therein. A light emitting device is secured to the fixed substrate at a position in the through-hole. A light receiving device is provided in the sensor substrate. A dummy light receiving device is formed between the light receiving device and the through-hole, around the through-hole, and in the sensor substrate. The light receiving device and the dummy light receiving device are made of an impurity diffusion layer having a same conductive type as a conductive type of a surface layer of the sensor substrate. The dummy light receiving device is deeper than the light receiving device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.