To hold optical parts such as lenses in multi-stages without being influenced by expansion, contraction, etc., b engaging a projecting part provided in the center in the length direction of one of the optical parts arranged above and below with a recessed part on a confronting surface provided in the center in the length direction of the other optical part for limiting the move of the projecting part along the length and direction positioning it.
A toric lens (the first lens) 1 arranged on the upper stage along the length and a toric lens (the second lens) 2 arranged on the lower stage are both molded with a plastic. And, the first lens 1 on the upper stage can be positioned along the length only by engaging a projection 3a for fitting formed on an upper edge flange part 2b of the second lens 2 in the lower stage with a recessed part 4 for fitting formed on a lower edge flange part 1c. Thus, since a deformation due to heat expansion, etc., is produced in the direction of the length, the center of the optical axis is not deflected along the length and optical performances such as imaging are not influenced by the deformation.
SATO HIROSHI
KIMURA KAZUMI
