US Patent 11218660 Pixel sensor having shared readout structure

An apparatus comprises a first photodiode, a second photodiode, a charge sensing unit, a quantizer, a memory, and a controller configured to: set a first exposure period in which the first photodiode generates a first charge; set a second exposure period in which the second photodiode generates a second charge, the second exposure period being set based on the first exposure period and at least one of: a first time associated with a read out operation of the memory to a second apparatus, or a second time associated with a quantization operation by the quantizer; perform, using the quantizer, the first quantization operation of the first charge to generate a first digital output; store the first digital output in the memory; perform, using the quantizer, a second quantization operation of the second charge to generate a second digital output; and store the second digital output in the memory.