Imaging element, imaging device, endoscope, endoscope system, and method of driving imaging element

1. An imaging sensor comprising:

a plurality of pixels arranged into a two-dimensional matrix, configured to receive light from outside, and configured to generate and output an imaging signal according to an amount of light received;

a first transfer line connected to the pixel and configured to transfer the imaging signal;

a reference voltage generation circuit configured to generate a first voltage and a second voltage lower than the first voltage; and

a control circuit configured to:

perform a selection operation of selecting a selection target pixel from among the plurality of pixels in order to read the imaging signal out to the first transfer line and a de-selection operation of canceling the selection of the pixel being selected;

perform the selection operation of selecting a new selection target pixel after performing the de-selection operation on the basis of a synchronization signal from outside; and

update a counter value representing a pixel line in accordance with the synchronization signal,

wherein the pixel includes:

a photoelectric converter configured to perform photoelectric conversion according to the amount of light received and accumulate a charge;

a first transfer transistor configured to transfer the accumulated charge;

a charge converter configured to convert the transferred charge into the imaging signal;

a pixel reset transistor connected to the reference voltage generation circuit and the charge converter and configured to reset the charge converter to the first voltage by supplying the first voltage generated by the reference voltage generation circuit; and

a pixel amplification transistor including a gate connected to the charge converter, the pixel amplification transistor being connected to the reference voltage generation circuit and the first transfer line, being turned on at a time the first voltage is applied to the gate, and being turned off at a time the second voltage is applied to the gate, and

wherein the control circuit is configured to perform the selection operation by turning on the pixel amplification transistor of the selection target pixel and perform the de-selection operation that cancels selection of the selected pixel by turning off the pixel amplification transistor of the selected pixel, and

wherein the control circuit is configured to perform the selection operation of the pixel line represented by the updated counter value after performing the de-selection operation of the pixel line before the update every time the synchronization signal is input.

2. An endoscope comprising:

an elongated insertion structure configured to be inserted into a cavity; and

the imaging sensor according to claim 1 , wherein the imaging sensor is arranged at a distal end side of the elongated insertion structure.

3. A system comprising:

an elongated insertion structure configured to be inserted into a cavity;

the imaging sensor according to claim 1 , wherein the imaging sensor is arranged at a distal end side of elongated insertion structure; and

a processor configured to convert the imaging signal into an image signal.

4. A method of driving an imaging sensor including:

a plurality of pixels arranged into a two-dimensional matrix, configured to receive light from outside, and configured to generate and output an imaging signal according to an amount of light received, each pixel including:

a photoelectric converter configured to perform photoelectric conversion according to the amount of light received and accumulate a charge;

a first transfer transistor configured to transfer the accumulated charge;

a charge converter configured to convert the transferred charge into the imaging signal; a pixel reset transistor configured to reset the charge converter; and

a pixel amplification transistor including a gate connected to the charge converter; and

a first transfer line connected to the pixel and configured to transfer the imaging signal, the method comprising:

generating a first voltage and a second voltage lower than the first voltage;

resetting the charge converter to the first voltage by supplying the first voltage generated;

performing a de-selection operation which cancels, in a pixel line represented by a counter value, selection of a selected pixel in order to read the imaging signal out to the first transfer line on the basis of a synchronization signal from outside by turning off the pixel amplification transistor by applying the second voltage to the gate of the pixel amplification transistor;

updating the counter value representing the pixel line in accordance with the synchronization signal;

performing a selection operation which selects, in a pixel line represented by the counter value updated in the updating, a selection target pixel from among the plurality of pixels in order to read the imaging signal out to the first transfer line after the de-selection step by turning on the pixel amplification transistor by applying the first voltage to the gate of the pixel amplification transistor; and

reading the imaging signal out to the first transfer line from the selected pixel.