Canon patent: 55mm F1.24 Lens With Double Gauss Element Arrangement

September 14, 2023
Canon Patents
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Another Canon patent, although we doubt that this one will ever hit the market.

Canon patent application 2023127280 (Japan, published 9/13/2023) discusses optical formulas for a 55mm F1.24 lens with a double Gauss element arrangement.

From the patent literature:

An object of the present invention is to provide an optical system that has a bright F number, is compact, has high optical performance, and also suppresses fluctuations in various aberrations associated with focusing.

Background Art

In recent years, photographing optical systems with a standard angle of view, where the half angle of view is about 20 degrees to 30 degrees, used in imaging devices have a bright F number and have high optical performance despite the small size of the entire system. That is required. A so-called double Gauss type optical system is known as a standard angle of view photographing optical system. In a Gauss type optical system, the lenses are arranged symmetrically around the aperture, and with a small number of lenses, it is possible to obtain high optical performance despite being compact.

However, in the optical system described in Patent Document 1, the back focus tends to become long and the total length of the lens becomes long, so it is difficult to suppress the increase in size of the imaging device.

In order to achieve a compact lens with a high F-number, high optical performance, and suppression of fluctuations in various aberrations associated with focusing, it is important to appropriately set the structure and material of the lens.

An object of the present invention is to provide an optical system that has a bright F number, is compact, has high optical performance, and also suppresses fluctuations in various aberrations associated with focusing.

Example 1