Japanese patent application 2010-282101 is for an optical communication between lens and camera body. The optical link will be added on the mount in addition to the regular electrical contacts (all Google translations):
"It is a camera accessory with which a camera body provided with the 1st communications department which communicates by contact, the 2nd communications department which communicates optically by non-contact."
Even more interesting, this optical communication will be available as an accessory:
"It is a camera accessory with which the camera body provided with the 2nd communications department which communicates optically by non-contact, and the body side mount can be equipped."
The patent application mentioned that this optical link will save space and will be more compact then conventional wiring.
The initial report from Japan indicated that this lens will be used in a mirrorless camera, but some of the drawing clearly show a DSLR type camera (D700 that is):
The above figure show the additional accessory 132 mounted on a DSLR. 136 are the electrical contacts (two or more) and 138 is the optical communication link:
"The mount surface 132 where the camera accessory in which it is equipped with the mount 130 here is close, It has two or more electric contact 136 and optical communication units 138 with which the mount nail (bayonet mount) 134 which projects in the radial-direction inside was matched inside the mount surface 132 in the mount surface and which are mentioned later. The mount surface 132 makes an annular flat surface. Two or more mount nails 134 are allotted, and make a circle, respectively."
This is a view of the lens mount: 126 are the electric contacts and 128 is the optical communication unit:
Here is a close up of the lens mount - again, 126 are the electric contacts and 128 is the optical contacts:
And a close up of the camera mount - 136 are the electrical contacts and 138 are the optical contacts:
Could this be an adapter for future lenses/DSLRs that will have a complete optical communications instead of wires? What say you?