Canon Patent Application: EF-M 32mm 1.4

This patent application appears to be for the EF-M 32mm 1.4.  I thought it may be interesting for those that are curious to see the thoughts behind the super sharp EF-M 32mm.

Interestingly, Canon's primary focus of the patent application is the bokeh.

Recently, the imaging apparatus using the imaging element while being compact, high image quality of the image quality is progressing. Particularly in single lens reflex cameras, in addition to improving the image quality at the time of image pickup, it is required that the blurring of the image is good. In order to satisfy these demands, in recent years, an imaging optical system with a large aperture ratio has been proposed in which Fno (F number) is made brighter so that blur amount can be controlled. As a lens type of an image pickup optical system satisfying this large aperture, for example, a double Gauss type is known. 

In order to improve the image quality and to improve the blurring taste, it becomes necessary to reduce chromatic aberration and suppress color bleeding. Although the double Gauss type imaging optical system can easily make a large aperture ratio, it is difficult to correct the field curvature well while correcting chromatic aberration. For this reason, there has been proposed an imaging optical system which deforms the double Gauss type to favorably correct various aberrations such as chromatic aberration and field curvature (Patent Documents 1 and 2). Patent Documents 1 and 2 are attempting to increase the aperture ratio while attaining high image quality by properly configuring the glass material and the refractive power arrangement of the lens disposed on the object side of the aperture stop.

The timeline is also interesting.  Canon filed the patent application April of 2017, released the lens in September 2018, and the Application finally gets published in November 2018.  It's still not an actual patent.  However with applications such as this Canon is most likely highly assured the patent will pass through the patent office without any problems.

Japan Patent Application 2018180366