Canon FF Mirrorless lens patent?

ahsanford

Particular Member
Aug 16, 2012
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I don't know my flange distances and mirrorless numbers like you do, but have a look:

http://egami.blog.so-net.ne.jp/2016-06-10

Translated:

Patent Publication No. 2016-102851
Published 2016.6.2
Filing date 2014.11.27
Example
Zoom ratio 1.00
Focal length 31.35
F-number 2.86
Angle of view 34.61
Image height 21.64
Overall length of the lens 85.29
BF 29.99
Patent of Canon
Positive ShiboTadashi
Diffractive optical element (the second group of aperture stop image side)
Correct axial chromatic aberration and lateral chromatic aberration of the near-infrared light
[0001]

The present invention relates to a magnification chromatic aberration correction of the imaging optical system used in a near infrared region from the visible region is suitable especially monitoring optical system.


FF mirrorless lens, or just an EF lens -- what say ye? And this would be a DO lens, ya?

- A
 
The patent refers to it as a video surveillance application. They emphasis surveillance multiple times in the patent and never mention still photography.

The patent is for a surveillance camera lens that can work with near infrared light, it has absolutely nothing to do with mirrorless!!


Here is a sniped of a paragraph from the patent. Translated into pseudo English, of course.


"In a video camera or a surveillance camera, photographing is usually performed in the wavelength zone of visible light. At this time, coating which has an infrared reflection property between a photographing optical system and an image sensor at an infrared cut filter or a lens is provided, and it is carrying out as [ be / by intercepting infrared light / the image photoed / subject to the influence of infrared light ].
[0003]
On the other hand, especially in a surveillance camera, photographing in dark situations, such as night, is called for as photographing under environment different from this. In that case, it is important to take a photograph by high sensitivity, and by incorporating from visible light to a near infrared, light volume can be secured rather than incorporating only near-infrared rays. Therefore, the imaging optical system used for high sensitivity photographing at night is asked for the optical system by which the chromatic aberration was satisfactorily corrected from visible light to the near infrared. "

More:
"Especially in a surveillance camera, a wide-angle lens is used in many cases, and an optical system becomes a retro type. Then, it is visible to become problem or it is that the variation in the high image height of the amount of chromatic aberration of magnification in each wavelength to ******** enlarges. Change by the high image height of the amount of chromatic aberration of magnification in each wavelength is expressed as a bend of the chromatic aberration of magnification on these Descriptions."
 
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