Image pixels with in-column comparators
US9967489B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 2016 |
| Grant date | May 8, 2018 |
| Priority date | — |
| Expiry date | Oct 6, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/812
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Image sensors may include imaging pixels that have comparators to read out image pixel signals. An imaging pixel may include a photodiode, a floating diffusion region, and a transfer transistor that transfers charge from the photodiode to the floating diffusion region. The floating diffusion region may be coupled to a source follower transistor. The source follower transistor may be coupled to a current source. A row select transistor may be interposed between the source follower transistor and the current source. To form an in-column comparator stage and reduce power consumption, an additional transistor may be interposed between the row select transistor and the current source. The additional transistor may be a pMOS transistor and the source follower transistor may be an nMOS transistor. The additional transistor may have a gate that receives a searching voltage that is ramped from a maximum value to a minimum value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.