Patent ID: 7460319

Claim:
A monitoring lens apparatus comprising: a fixed cylinder; a first lens frame disposed inside the fixed cylinder, the first lens frame being movable in an optical axis direction; a second lens frame disposed inside the fixed cylinder, the second lens frame being movable in the optical axis direction; a first ring pivotable to the fixed cylinder, the first ring having a cam for driving the first lens frame; a second ring pivotable to the fixed cylinder, the second ring being disposed on an object side of the first ring and having a cam for driving the second lens frame; an extended portion provided integrally with the first ring and extended to the object side to cover an outer periphery of the second ring, and a lock knob inserted to an open hole portion at the extended portion, the lock knob being engaged with a screw hole at the second ring for fixing both of rotational positions of the first and the second rings.