Application of an image sensor with the function for detecting a modulated light signal to digital camera preventing black out and white out effect

Black outs and white outs of captured images usually occur due to shortages of dynamic range. To reduce black outs and white outs, we investigated the applicability of an image sensor with a function for detecting a modulated light signal. The image sensor was fabricated originally to detect light whose intensity was modulated with a certain frequency. The image sensor can also capture two images almost simultaneously. Both bright (long exposure time) and dark (short exposure time) images can be captured almost simultaneously using this sensor. Two images, one of each kind, are appropriately compounded to generate an output image in which the black out and white out is reduced. Experimental results showed that the image sensor can reduce black out and white out. Unwanted effects caused by changes of light intensity during exposure were also drastically reduced.