Ambient light sensor
US7838811B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2008 |
| Grant date | Nov 23, 2010 |
| Priority date | — |
| Expiry date | May 13, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In an ambient light sensor according to the present invention, a current amplification portion which amplifies a light current obtained by a light receiving portion to generate an output signal includes: a current amplification stage that has: a first current mirror amplifier which is composed of a bipolar transistor, and a second current mirror amplifier which is composed of a field effect transistor connected in parallel with the first current mirror amplifier; and a changeover control circuit which monitors an amplified current input into the current amplification stage, and performs changeover control of the first and second current mirror amplifiers according to a value of the amplified current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.