Simultaneous global shutter and correlated double sampling read out in multiple photosensor pixels
View Patent ↗An apparatus controls operation of an array of color multiple sensor pixel image sensors to provide a global shuttering for one half of the color multiple sensor pixel image sensors and a rolling shuttering for all color multiple sensor pixel image sensors of the array. The apparatus includes a row control circuit and a column clamp, sample, and hold circuit. The row control circuit generates the necessary reset control signals, transfer gating signals, and row selecting signals for providing the global shuttering and the rolling shuttering color multiple sensor pixel image sensors. The column clamp, sample and hold circuit generates an output signal representative of a number of photons impinging upon each color multiple sensor pixel image sensor of the row of selected color multiple sensor pixel image sensors. The control apparatus further includes an analog to digital converter which converts the read out signal to a digital image signal.
1. A device comprising:
a plurality of rows of image sensors configured to sense light corresponding to an image, each image sensor including a first light sensing device and a second light sensing device; and
a control device configured to:
read a first voltage from the first light sensing device as part of a global shuttering operation associated with the plurality of rows of image sensors;
read a second voltage from the second light sensing device as part of a rolling shuttering operation associated with the plurality of rows of image sensors, wherein voltages of each image sensor are read one row at a time from the plurality of rows of image sensors;
generate an image output signal based, at least in part, on the voltages read from the plurality of rows of image sensors for both the global shuttering operation and the rolling shuttering operation; and
initiate a next global shuttering operation after the voltages for all of the plurality of rows of image sensors have been read.
2. The device of claim 1 , wherein the control device is further configured to:
select an image sensor;
read a voltage level corresponding to the light from the selected image sensor;
reset the selected image sensor;
read a reset voltage level corresponding to the selected image sensor after the reset of the selected image sensor; and
generate an image output signal based, at least in part, on the light sensed by the selected image sensor and the reset voltage level corresponding to the selected image sensor.
3. The device of claim 1 , wherein the control device is further configured to sequentially read both the first voltage and the second voltage from each image sensor in the rolling shuttering operation.
4. The device of claim 1 , wherein the control device further comprises:
a row control circuit configured to select a row of the image sensors to transfer voltage levels corresponding to light sensed by the image sensors in the selected row and to transfer reset voltage levels of the image sensors in the selected row; and
a column control circuit configured to combine the voltage levels and the reset voltage levels corresponding to each image sensor in the selected row to generate image voltage levels, and generate an image output signal from the image voltage levels.
5. The device of claim 1 , wherein the first light sensing device is configured to generate the first voltage with a magnitude corresponding to a magnitude of light sensed by the first light sensing device, and wherein each image sensor further comprises:
a storage node configured to store the first voltage; and
a first transfer switch configured to transfer the first voltage from the first light sensing device to the storage node.
6. The device of claim 5 , wherein each image sensor further comprises a reset switch configured to set the storage node to a reset voltage.
7. The device of claim 6 , wherein the second light sensing device is configured to generate the second voltage with a magnitude corresponding to a magnitude of light sensed by the second light sensing device and wherein each sensor further comprises a second transfer switch configured to set the storage node to the second voltage from the reset voltage.
8. The device of claim 7 , wherein each image sensor further comprises an output switch configured to provide the control device an output corresponding to a voltage level of the storage node.
9. A method comprising:
reading, by a control device, a first voltage corresponding to light sensed by a first light sensing device in an image sensor as part of a global shuttering mode of operation associated with a plurality of rows of image sensors, wherein each image sensor comprises a first light sensing device and a second light sensing device;
selectively reading, by the control device, a second voltage corresponding to light sensed by a second light sensing device in the image sensor as part of a rolling shuttering mode of operation of the control device, wherein voltages of each image sensor are read one row at a time from the plurality of rows of image sensors;
generating, by the control device, an image output signal corresponding to the image sensor from the first voltage and selectively from the second voltage based on the shuttering mode of the control device; and
initiating, by the control device, a next global shuttering mode of operation after the voltages for all of the plurality of rows of image sensors have been read.
10. The method of claim 9 , further comprising reading, by the control device, at least one reset voltage of the image sensor.
11. The method of claim 10 , wherein generating the image output signal further comprises combining, by the control device, the first voltage and the reset voltage to determine at least a portion of the image output signal.
12. The method of claim 10 , wherein generating the image output signal further comprises combining, by the control device, the second voltage and the reset voltage to determine at least another portion of the image output signal.
13. The method of claim 9 , wherein generating the image output signal further comprises:
combining, by the control device, the first voltage with a reset voltage of the image sensor to determine at least a first portion of the image output signal; and
combining, by the control device, the second voltage with the reset voltage of the image sensor to determine at least a second portion of the image output signal.
14. The method of claim 13 , wherein generating the image output signal further comprises sequentially arranging, by the control device, the first portion and the second portion in the image output signal.
15. The method of claim 9 , further comprising:
generating, by the control module, a series of images including a first image based on voltages corresponding to the light sensed by the first light sensing device of each image sensor during the global shuttering mode of operation; and
generating, by the control module, a second image of the series of images based on voltages corresponding to the light sensed by both the first light sensing device and the second light sensing device of each image sensor during the rolling shuttering mode of operation.
16. The method of claim 15 , wherein the first image has a resolution that is one half the resolution associated with the second image.
17. An apparatus including a computer-readable memory device storing instructions configured to cause a processing device to perform operations comprising:
reading a first voltage corresponding to light sensed by a first light sensing device in an image sensor as part of a global shuttering mode of operation associated with a plurality of rows of image sensors, wherein each image sensor comprises a first light sensing device and a second light sensing device;
selectively reading a second voltage corresponding to light sensed by a second light sensing device in the image sensor as part of a rolling shuttering mode of operation associated with the plurality of rows of image sensors, wherein voltages of each image sensor are read one row at a time from the plurality of rows of image sensors;
generating an image output signal corresponding to the image sensor from the first voltage and selectively from the second voltage based on the shuttering mode of operation associated with the plurality of rows of image sensors; and
initiating a next global shuttering mode of operation after the voltages for all of the plurality of rows of image sensors have been read.
18. The apparatus of claim 17 , wherein the operations further comprise reading at least one reset voltage of the image sensor.
19. The apparatus of claim 18 , wherein generating the image output signal further comprises combining the first voltage and the reset voltage to determine at least a portion of the image output signal.
20. The apparatus of claim 18 , wherein generating the image output signal further comprises combining the second voltage and the reset voltage to determine at least another portion of the image output signal.
21. The apparatus of claim 17 , wherein generating the image output signal further comprises:
combining the first voltage with a reset voltage of the image sensor to determine at least a first portion of the image output signal; and
combining the second voltage with the reset voltage of the image sensor to determine at least a second portion of the image output signal.
22. The apparatus of claim 21 , wherein generating the image output signal further comprises sequentially arranging the first portion and the second portion in the image output signal.