Patent ID: 6324021
Filing Date: 2001-11-27
Classification: G02B

Abstract:
An optical focusing system, comprising:an objective lens assembly;an eyepiece lens assembly mounted in axial alignment with respect to said objective lens assembly;a lens mount for receiving said eyepiece lens assembly, said eyepiece lens assembly slidably mounted to said lens mount, said lens mount being adapted to allow linear movement of said eyepiece lens assembly with respect to said objective lens assembly within a predetermined distance;a spindle rotatably mounted in said eyepiece lens assembly and extending through said lens mount;a knob portion fixedly attached to said spindle, wherein said knob portion is operable to rotate said spindle; andlinkage to transmit rotational movement of said spindle to cause linear movement of said eyepiece lens assembly with respect to said objective lens assembly, whereby rotation of said spindle can selectively vary the distance between said eyepiece lens assembly and said objective lens assembly to select the desired plane of focus, said linkage comprising a longitudinally disposed cord fixedly and tautly attached to opposite ends of said lens mount, said cord wound around said spindle at least one revolution, whereby rotational movement to said spindle causes said spindle to move along the length of said cord.