Device for illuminating indicia in the viewfinder of a camera

Claim 1

In a single lens reflex camera having an automatic diaphragm, the combination comprising: a viewfinder; a scale device disposed in said view finder, said scale device being observed through said viewfinder and illuminated with part of the light passing through the objective lens; a manually operable member connected to said automatic preset diaphragm for stopping down the diaphragm to a preset f-value during operation of said manually operable member; electrically illuminating means associated with said manually operable member to illuminate said scale device during operation of said manually operable member; wherein said electrically illuminating means includes a circuit having a lamp, a source of electric potential, a pair of switch members and connections for connecting the lamp and said switch members to said source, said switch members being associated with said manually operable member for closing the circuit to turn on said lamp during operation of said manually operable member and opening the circuit to turn off the lamp while the operable member is inoperative.