Lens assembly having automatic thermal focus adjustment

摘要

A lens assembly especially adapted for mounting in an environment subject to variable temperatures, such as a projection television set, including an automatic thermal focus adjustment. A lens mount is formed from a material having a first coefficient of thermal expansion and carries at least one lens. A focus mount is coupled to the lens mount and is formed from a material having a second coefficient of thermal expansion different from the first coefficient of thermal expansion. Adjustment and locking structure couples the lens mount to the focus mount and allows the lens mount to be axially adjusted relative to the focus mount and then locked in position. In use, the relative axial positions of the lens mount and focus mount automatically change to move the lens in response to a temperature change in the environment of use and after being locked in position with the adjustment and locking structure.