CMOS image sensor with dual floating diffusions per pixel for flicker-free detection of light emitting diodes
US9936153B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2016 |
| Grant date | Apr 3, 2018 |
| Priority date | — |
| Expiry date | Oct 4, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/811
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatuses and methods for image sensors with pixels that reduce or eliminate flicker induced by high intensity illumination are disclosed. An example image sensor may include a photodiode, a transfer gate, an anti-blooming gate, and first and second source follower transistors. The photodiode may capture light and generate charge in response, and the photodiode may have a charge capacity. The transfer gate may selectively transfer charge to a first floating diffusion, and the anti-blooming gate may selectively transfer excess charge to a second floating diffusion when the generated charge is greater than the photodiode charge capacity. The first source-follower transistor may be directly coupled to the first floating diffusion by a gate, the first source-follower to selectively output a first signal to a first bitline in response to enablement of a first row selection transistor, and the second source-follower transistor may be capacitively-coupled to the second floating diffusion, the second source-follower to selectively output a second signal to a second bitline in response to enablement of a second row selection transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.