Abstract: A lens assembly has: optical members including lenses and spacing rings; and a ceramic lens frame into which the optical members are inserted. A solid lubricant is applied to at least one of a part of the inner peripheral surface of the ceramic lens frame, which part is to be in contact with at least the outer peripheral surfaces of the optical members, and the outer peripheral surfaces of the optical members. Subsequently, the lenses and spacing rings are alternately inserted into the ceramic lens frame and then pressed by a pressing ring.

Abstract: A lens assembly is provided and includes: a lens frame; and a lens frame having a hollow part into which the lens is inserted. The lens frame has a bonding hole into which an adhesive agent is injected for bonding and fixing to the lens frame the lens inserted into the lens frame and which passes through an outer wall of the lens frame and an inner wall of the hollow part.

Abstract: A lens assembly is provided and includes: a plurality of lenses including a first lens located nearest to an object side of the lens assembly and a second lens located adjacent to the first lens; and a lens frame having a hollow part which includes an opening on each of an object side and an image forming side of the lens assembly and into which the plurality of lenses are inserted with their optical axes aligned. Liquid is sealed in a part between the first lens and the second lens.