Image pickup system, method for driving image pickup elements, and recording medium
An image pickup system includes an image pickup element with an image pickup region in which a plurality of pixels are arranged in a matrix, and a controller configured to control reading of signals from the pixels. The controller divides a first frame period in which a first image is read from the image pickup element into a plurality of divided frame periods, including first and second divided frame periods. When the number of pixels included in the first image is larger than the number of pixels included in a second image, a second frame period required for reading all signals from the pixels included in the second image is inserted between the first and second divided frame periods. A refresh cycle of the second image is shorter than a refresh cycle of the first image.
1. An image pickup system comprising: an image pickup element including an image pickup region in which a plurality of pixels are arranged in a matrix; and a controller configured to control reading of signals from the plurality of pixels, wherein the controller divides a first frame period, in which a first image is read from the image pickup element, into a plurality of divided frame periods including first and second divided frame periods, wherein, when a number of pixels included in the first image is larger than a number of pixels included in a second image, a second frame period required for reading all signals from the pixels included in the second image is inserted between the first and second divided frame periods, wherein a refresh cycle of the second image is shorter than a refresh cycle of the first image, and wherein, when the first divided frame period is shorter than the second divided frame period, the controller adds a waiting time to the first divided frame period so that a sum of the first divided frame period and the waiting time is equal to the second divided frame period.
2. The image pickup system according to claim 1 , wherein, when n second images are employed, n being a natural number, the first frame period is divided into n+1 or more divided frame periods.
3. The image pickup system according to claim 1 , wherein, when a plurality of second images corresponding to portions of the image pickup region are employed, one of the second frame periods is inserted between the first and second divided frame periods.
4. The image pickup system according to claim 1 , wherein, when a number of pixels read in the first divided frame period is smaller than a number of pixels read in the second divided frame period, the controller controls a frequency of scanning of the pixels read in the first divided frame period to be lower than a frequency of scanning of the pixels read in the second divided frame period.
5. The image pickup system according to claim 1 , further comprising:
a region selecting unit configured to set regions in the image pickup region corresponding to the first and second images.
6. The image pickup system according to claim 1 ,
wherein the first image corresponds to the image pickup region in its entirety, and
wherein the second image corresponds to a portion of the image pickup region.
7. The image pickup system according to claim 6 , wherein a density of the pixels included in the first image is lower than a density of the pixels included in the second image.
8. The image pickup system according to claim 1 ,
wherein the first image corresponds to a portion of the image pickup region,
wherein the second image corresponds to the image pickup region in its entirety, and
wherein a density of the pixels included in the first image is higher than a density of the pixels included in the second image.
9. A method for driving an image pickup element so that signals are read from pixels included in first and second images and output from the image pickup element, the image pickup element including an image pickup region in which a plurality of pixels are arranged in a matrix, the method comprising: dividing, using a controller, a first frame period, in which signals are read from the pixels included in the first image, into a plurality of divided frame periods including first and second divided frame periods, when a number of the pixels included in the first image is larger than a number of the pixels included in the second image, inserting a second frame period, which is required for reading all signals from the pixels included in the second image, between the first and second divided frame periods, making a refresh cycle of the second image shorter than a refresh cycle of the first image, and adding a waiting time to the first divided frame period so that a sum of the first divided frame period and the waiting time is equal to the second divided frame period, when the first divided frame period is shorter than the second divided frame period inserting the divided frame period.
10. The method for driving an image pickup element according to claim 9 , wherein, when n second images are employed, n being a natural number, the first frame period is divided into n+1 or more divided frame periods.
11. The method for driving an image pickup element according to claim 9 , wherein, when a plurality of second images corresponding to portions of the image pickup region are employed, a second frame period is inserted between the first and second divided frame periods.
12. The method for driving the image pickup element according to claim 9 , wherein, when a number of pixels read in the first divided frame period is smaller than a number of pixels read in the second divided frame period, a frequency of scanning of the pixels read in the first divided frame period is lower than a frequency of scanning of the pixels read in the second divided frame period.
13. The method for driving the image pickup element according to claim 9 ,
wherein the first image corresponds to the image pickup region in its entirety, and
wherein the second image corresponds to a portion of the image pickup region.
14. The method for driving the image pickup element according to claim 13 , wherein a density of the pixels included in the first image is lower than a density of the pixels included in the second image.
15. The method for driving the image pickup element according to claim 9 ,
wherein the first image corresponds to a portion of the image pickup region, and
wherein the second image corresponds to the image pickup region in its entirety.
16. A computer-readable recording medium storing a computer program that when executed by a computer causes the computer to perform a method for driving an image pickup element so that signals are read from pixels included in first and second images and output from the image pickup element, wherein the image pickup element including an image pickup region in which a plurality of pixels are arranged in a matrix, and wherein the method includes: dividing a first frame period, in which signals are read from the pixels included in the first image, into a plurality of divided frame periods including first and second divided frame periods, when a number of the pixels included in the first image is larger than a number of the pixels included in the second image, inserting a second frame period, which is required for reading all signals from the pixels included in the second image, between the first and second divided frame periods, making a refresh cycle of the second image shorter than a refresh cycle of the first image, and adding a waiting time to the first divided frame period so that a sum of the first divided frame period and the waiting time is equal to the second divided frame period, when the first divided frame period is shorter than the second divided frame period.