It is very difficult to make lenses with a flat field, all of them have at least a small field of curvature.
The old 24-70mm F/2.8L was known for its field of curvature.
The Primary Driver behind the invention is the ability to modify the curvature of the sensor to match the lens, and, of course, third party lenses would not be recognized by the camera - hint -hint. However, it does mention a manual mode using the rear lcd with magnification.
Here is a different Translation.
The present invention relates to an imaging device and a control method for the same.
[Background of the Invention]
[0002]
There is aberration called a curvature of field in the image formation optical system used for imaging devices, such as a digital camera, and a gap of optical axis direction occurs in an image formation position in the central part and the periphery of an imaging surface. Therefore, with constituting an optical system combining a plurality of lenses conventionally, it had corrected so that curvature-of-field aberration might become small. On the other hand, the image sensor which corrects the above-mentioned curvature-of-field aberration is proposed by incurvating the image sensor, i.e., an imaging surface, itself these days. it becomes possible to simplify an optical system by incurvating an imaging surface and correcting curvature-of-field aberration -- many -- it is thought that the necessity of combining several lenses becomes small.
[0003]
With many cameras, the optical zoom function is mounted, and since the positions of a zoom lens differ according to zoom magnifying power, the state of a curvature of field also changes. According to the state of a curvature of field, the technology which controls the curvature which incurvates an imaging surface is proposed to it (Patent document 1).
The Dark Field Current thing is more of a "by the way"
"By the way, generally, with an image sensor, since dark current may occur and the noise by dark current may be especially conspicuous at the time of high sensitivity and long exposure, various noise reduction processings are performed. On the other hand, in the image sensor which incurvated the imaging surface, it turns out that the dark current which occurs in an image sensor by the tensile stress at the time of incurvating an image sensor is reduced.
However, the amount of dark current which will be reduced if the curvature which incurvates an imaging surface according to zoom magnifying power is changed as it describes in the Patent document 1 changes, and even if it performs noise reduction processing, a noise may be unable to be reduced sufficiently.
[0006]
The present invention is made in view of the problem mentioned above, and the purpose is to reduce the noise of a taken image effectively in the imaging device which has the function to incurvate an image sensor. "