Image pickup unit and image pickup display system
View Patent ↗An image pickup unit includes: an image pickup section having a plurality of pixels each including a photoelectric conversion device and a field effect transistor; and a driving section, by using the transistor, that executes read driving and reset driving on a signal charge stored in the pixel. The driving section intermittently executes the reset driving a plurality of times in a one-frame term, and executes on-operation of the transistor by applying, to the transistor over at least one resetting term in the one-frame term or over a partial term in the at least one resetting term, a second voltage that is lower than a first voltage applied in a resetting term in the one-frame term other than the at least one resetting term.
1. An image pickup unit, comprising:
an image pickup section having a plurality of pixels, each of the pixels including a photoelectric conversion device and a field effect transistor; and
a driving section configured to apply, during a first term, a first voltage to the transistor to execute read driving and reset driving on a signal charge stored in the pixel, the driving section further configured to execute the reset driving a plurality of times in a one-frame term by applying a second voltage to the transistor during at least one second term following the first term, wherein the second voltage is lower than the first voltage,
wherein the driving section is further configured to set the second voltage to be stepwise reduced in time series during the at least one second term.
2. The image pickup unit according to claim 1 , wherein the driving section is configured to apply the second voltage to the transistor at least in execution of final reset driving.
3. The image pickup unit according to claim 1 , wherein the at least one second term is shorter than the first term.
4. The image pickup unit according to claim 1 , wherein the second voltage is greater than a threshold voltage of the transistor.
5. The image pickup unit according to claim 1 , wherein the driving section is further configured to use the first voltage to execute first reset driving and the read driving at the same time during the first term and use the second voltage in execution of final reset driving.
6. The image pickup unit according to claim 1 , wherein the photoelectric conversion device is one of a positive-intrinsic-negative (PIN) type photodiode and a metal-insulator-semiconductor (MIS) type sensor.
7. The image pickup unit according to claim 1 , wherein the image pickup section is configured to generate an electric signal based on an incident radioactive ray.
8. The image pickup unit according to claim 7 , wherein the image pickup section includes, on the photoelectric conversion device, a wavelength conversion layer that converts a wavelength of the radioactive ray to allow the wavelength to be within a sensitive range of the photoelectric conversion device.
9. The image pickup unit according to claim 8 , wherein the radioactive ray is an X-ray.
10. The image pickup unit according to claim 1 , wherein a semiconductor layer of the transistor is made of one of amorphous silicon, polycrystalline silicon, microcrystalline silicon, and an oxide semiconductor.
11. An image pickup display system with an image pickup unit and a display that displays an image based on an image pickup signal obtained from the image pickup unit, the image pickup unit comprising:
an image pickup section having a plurality of pixels, each of the pixels including a photoelectric conversion device and a field effect transistor; and
a driving section configured to apply, during a first term, a first voltage to the transistor to execute read driving and reset driving on a signal charge stored in the pixel, the driving section further configured to execute the reset driving a plurality of times in a one-frame term by applying a second voltage to the transistor during at least one second term following the first term, wherein the second voltage is lower than the first voltage,
wherein the driving section is further configured to set the second voltage to be stepwise reduced in time series during the at least one second term.
12. The image pickup unit according to claim 1 , wherein each of the pixels comprises a passive-type pixel circuit.