Image flicker reduction with fluorescent lighting
AssigneeConexant Systems, Inc.
InventorsRandall M. Chung, Magued M. Bishay, Joshua Ian Pine
Life of this patent
Estimating the term…
Abstract
An imager reduces lighting induced flicker by setting its pixel integration time to an integral multiple of the periods between peak intensity of the lighting. In one implementation, flicker is reduced in a 30 Hz frame rate camera capturing an image lighted with 50 Hz lighting by setting the integration time to approximately 10 ms, the period between lighting intensity peaks.
Claims23
A method of reducing flicker caused by lighting having a periodic intensity using an imager having a pixel integration time, the method comprising the steps of:
- setting the integration time to an integral multiple of the period of the periodic intensity of the lighting;
- determining an amount to vary an overall system gain;
- and
- adjusting the overall system gain by adjusting the integration time while maintaining the integration time at an integral multiple of the period of the periodic intensity.
An imager for a digital camera with reduced flicker caused by lighting having a periodic intensity, the imager providing data for a plurality of pixels, the imager comprising:
- programmable integration time circuitry that controls an integration time of the plurality of pixels;
- an integration time adjustment block coupled to the programmable integration time circuitry, the integration time adjustment block setting the integration time to an integral multiple of the period of the periodic intensity of the lighting;
- and
- an overall gain control block that adjusts an overall system gain by adjusting the integration time while maintaining the integration time at an integral multiple of the period of the periodic intensity.
An imager providing data for a plurality of pixels for a digital camera with reduced flicker caused by lighting having a periodic intensity, the imager comprising:
- means for controlling an integration time of the plurality of pixels to an integral multiple of the period of the periodic intensity of the lighting;
- and
- means for varying an overall system gain by adjusting the integration time while maintaining the integration time at an integral multiple of the period of the periodic intensity of the lighting.
Dependencies are inferred from the claim text.