Canon Patents a New Lens Mount

Canon has applied for a patent for a brand new camera lens mount design that’s similar to its EF and EF-M mounts.

Canon News first reported on the patent (#2018-084713), writing that the design may be a first hint at what’s to come in Canon’s upcoming full-frame mirrorless camera(s).

Here’s a rough translation of the patent’s text by Canon News:

Conventionally, the serial communication (synchronous serial communication) of a clock synchronization system has been adopted as a communication method of a camera and an interchangeable lens. The following technical contents are disclosed in the Patent document 1. First, synchronous serial communication is performed with the first communication speed with which an interchangeable lens old type can also communicate. When the interchangeable lens with which it is equipped is distinguished from a new lens by the communication content, it changes to the synchronous serial communication in a more nearly high-speed second communication speed.

The wording seems to suggest that the lens mount is able to handle both “old” and “new” style lenses — perhaps Canon is aiming to have one hybrid mount that can handle both EOS-M mirrorless and EOS EF full frame lenses.

Here’s the design of the new mount:

And here’s the design of the existing EF and EF-M mounts (diagrams via

While the EF-M mount has 9 contacts and the EF mount has 8, the new mount only has 7.

“We’ve been told that the mount solution for a full frame mirrorless camera would be interesting, but this is the first time we can confirm that Canon is working on a new mount,” Canon Rumors writes. “Though there’s no way of knowing if this is indeed for the upcoming full frame mirrorless camera body.”