Nikon’s patent for electrically controlled optical low-pass filter


Nikon filed a patent in Japan (2013-156379) for electrically turning ON or OFF the optical low-pass (OLPF) a.k.a. anti-aliasing (AA) filter. Currently the Nikon D800E and D7100 do not have AA filters on their sensors. Nikon filed a similar patent back in 2011 which offered a mechanical ON/OFF solution. Another patent from last year suggested adding the OLPF inside the lens. Detailed description from the recent patent filing:

While ejecting the polarization direction of one of the object image ejected from the incidence side double reflex part which separates the object image which entered as one mode of the present invention according to a polarization direction, and the aforementioned incidence side double reflex part as it is, A light separation unit provided with the liquid crystal part which rotating other polarization directions by electric control from the outside switches whether lends and there is, and is ejected, and the injection side double reflex part which separates the object image ejected from the aforementioned liquid crystal part according to a polarization direction is provided. The outline of the above-mentioned invention is not what enumerated all the required characteristics of the present invention. The sub combination of these characterizing group can also be invented.


The above drawing is a mimetic diagram which describes the structure of the image sensor 330 notionally. A many photo detector is arranged in two dimensions in the imaging surface of the image sensor 330. A photo detector is formed of a photo-diode, a photo-transistor, etc., accumulates the electric charge according to the strength of incident light, and outputs it as an electrical signal.

Red and the color filter that transmits either green and blue put on the photo detector arranged in two dimensions. The one unit pixel 331 is formed combining four photo detectors located in a line with a square among these photo detectors. The unit pixel 331 is provided with the following. For example, it is one at a time about a photo detector which has a filter which transmits red and blue. Two photo detectors which have a filter which transmits green with human being’s high light-receiving sensitivity. Such a square unit pixel 331 turns into a pixel in the case of carrying out color photography in the highest resolution in the image sensor 330. (machine translation via Egami and Japan Patent Office)

This entry was posted in Nikon Patents and tagged . Bookmark the permalink. Trackbacks are closed, but you can post a comment.
  • FCC disclosure statement: this post may contain affiliate links or promotions that do not cost readers anything but help keep this website alive. As an Amazon Associate, I earn from qualifying purchases. When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network. Thanks for your support!

  • Back to top