Patent ID: 11953373
Assignee: JAPAN DISPLAY INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 0:
1. A sensor device comprising:
a sensor configured to output a sense signal, a value of the sense signal changing over time based on incident light;
a first reset circuit configured to set the value of the sense signal to a reset value when the value of the sense signal exceeds a threshold;
a counter configured to count a first number of times of reset by the first reset circuit; and
an arithmetic operation circuit configured to calculate an amount of incident light of a certain period based on the value of the sense signal, the reset value, and the first number of times of reset,
wherein
the sensor comprises
a photodiode configured to generate current based on the incident light and including a terminal connected to an output terminal of the sensor,
a capacitor charged with the current,
a first transistor configured to set the voltage of the terminal of the photodiode to a reset voltage based on the reset value,
a second transistor configured to supply a constant current based on a charged voltage of the capacitor, and
a third transistor configured to be conductive for the certain period and output the constant current from the sensor,
the first reset circuit comprises a comparator configured to generate a first reset signal when the value of the sense signal is less than or equal to the threshold,
the sensor device further comprises
a second reset circuit configured to generate a second reset signal when the certain period is terminated, and
a circuit element configured to supply the first reset signal or the second reset signal to a control terminal of the first transistor,

the sensor comprises a plurality of sensor units in a two-dimensional array of n rows×m columns, where n and m are arbitrary positive integers,
the first reset circuit comprises m reset units,
each of the m reset units is connected to the sensor units of each of the columns,
the second reset circuit comprises n second reset terminals, and
each of the n reset terminals is connected to the sensor units of each of the rows.