Image pickup device, imaging apparatus containing the same, and control method thereof
An object of the present invention is to provide an imaging apparatus capable of obtaining a sufficient resolution in a picture signal for zooming in on an output signal of an image pickup device by means of an electronic zoom process and a control method thereof. To attain this object, a timing generator generates a timing signal for controlling timing for reading charges to an image pickup device and the timing for mixing or transferring the charges. A zoom control portion determines a scaling factor for, by signal processing, expanding or reducing picture data generated based on the output signal of the image pickup device. The zoom control portion also determines the number of mixed pixels and a cutout range of the charges in the image pickup device. A vertical scaling factor control portion controls the timing generator so that mixture of the charges and charge transfer will be compliant with the number of mixed pixels and the cutout range respectively as determined by the zoom control portion.
1. An imaging apparatus comprising:
an image pickup element having an imaging area in which a plurality of light receiving elements are two-dimensionally placed;
an amplifier that amplifies an output of said image pickup element;
a zoom operation unit for a user to operate expansion or reduction of an image; and
a controller that controls to drive said image pickup element with a first shutter speed of an electronic shutter and mix a first number of pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to a first amplification ratio, in a case that a first magnification is set by said zoom operation unit, to drive said image pickup element with a second shutter speed of the electronic shutter and mix a second number of pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to the first amplification ratio, in a case that a second magnification, which is larger than the first magnification, is set by said zoom operation unit, wherein the second shutter speed is lower than the first shutter speed and the second number is smaller than the first number, and to drive said image pickup element with the second shutter speed of the electronic shutter and not mix pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to a second amplification ratio, which is larger than the first amplification ratio, in a case that a third magnification, which is larger than the second magnification, is set by said zoom operation unit.
2. A method of controlling an imaging apparatus comprising an image pickup element having an imaging area in which a plurality of light receiving elements are two-dimensionally placed, an amplifier that amplifies an output of the image pickup element, and a zoom operation unit for a user to operate expansion or reduction of an image, said method comprising the step of:
controlling to drive said image pickup element with a first shutter speed of an electronic shutter and mix a first number of pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to a first amplification ratio, in a case that a first magnification is set by said zoom operation unit, to drive said image pickup element with a second shutter speed of the electronic shutter and mix a second number of pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to the first amplification ratio, in a case that a second magnification, which is larger than the first magnification, is set by said zoom operation unit, wherein the second shutter speed is lower than the first shutter speed and the second number is smaller than the first number, and to drive said image pickup element with the second shutter speed of the electronic shutter and not mix pixel signals in the image pickup element, which is output from the plurality of light receiving elements, and set said amplifier to a second amplification ratio, which is larger than the first amplification ratio, in a case that a third magnification, which is larger than the second magnification, is set by said zoom operation unit.