Patent ID: 8847160

Claim:
A bolometric sensing circuit comprising: a pixel array comprising of a plurality of pixels, each pixel comprising of a sensor configured of a light receiving portion to convert incident photons into heat and a sensing portion integrated with the light receiving portion and having a resistance varying according to the converted heat, a mechanical structure that moves in response to an applied voltage that pulls the sensing area into intimate contact with a thermal sink such that the temperature of the sensor is equalized with the substrate, thereby thermally resetting the sensor; an output portion configured to output a common mode voltage that represents a voltage derived from the sensing portion from which accumulated heat has been removed in response to a heat removing voltage actuated mechanical thermal reset of the sensing portion, and an output of a sensed voltage that represents a voltage of the sensing portion which has accumulated heat for an integration period after being thermally reset; a memory configured to store the common mode voltage and the sensed voltage; and a processor configured to subtract the common mode voltage from the sensed voltage to produce a signal representation that represents a change in resistance of the sensing portion due to the heat accumulated for the integration period, wherein a read out of the common mode voltage and the sensed voltage occurs during one scan period in which desired number of pixels are read out, the one scan period includes a first period before the common mode voltage is read out and a second period after the common mode voltage is read out, and the output portion is further configured to comprise: a storage configured to store the common mode voltage for the first period and to store the sensed voltage for the second period; and a switching portion configured to output the common mode voltage to the memory after the first period and subsequently output the sensed voltage after the second period.