Abstract: A lens holding member (30) is molded by filling a molten synthetic resin from a gate of a mold into a product cavity, and a portion corresponding to the gate of the mold for molding remains thereon as a gate portion (72). By mounting a coil (52) on a rear cylindrical face (60), an adhesive filling recess (70) that opens in a direction parallel to an optical axis of an image pickup optical system (28) is defined by a center face (66), side faces (68) standing from both sides of the center face (66), an outer face (58), and an inner peripheral surface of the coil (52). The gate portion (72) is provided on the center face (66) of the adhesive filling recess (70). By filling the adhesive filling recess (74) with adhesive B, an outer peripheral portion of the lens holding member (30) and an inner peripheral portion of the coil (52) are bonded together, and the gate portion (72) is buried in the adhesive B.

Abstract: A mounting structure for a plurality of lenses, wherein at least three lenses are arranged with their optical axes set to coincide with each other, the lenses located at both ends in the optical axis direction are provided with parts facing each other, and the mutually facing parts of the lenses are fixed to each other with an adhesive. The mounting structure, wherein all the lenses except the lenses located at both ends in the optical axis direction are fixed in the state of being clamped between the lenses located at both ends in the optical axis direction by shrinkage during curing of the adhesive.

Abstract: A variable power optical system composed of a first optical part, a second optical part, and a third optical part, with the first optical part being movable with respect to the second and third optical parts to change the focal length of the entire system. The first optical part is movably held between the second optical part and the third optical part. The first optical part moves in the direction perpendicular to the optical axis over a distance between the position on the optical system of the entire system and the position of retraction from the optical axis of the entire system.

Abstract: A lens holding member (30) is molded by filling a molten synthetic resin from a gate of a mold into a product cavity, and a portion corresponding to the gate of the mold for molding remains thereon as a gate portion (72). By mounting a coil (52) on a rear cylindrical face (60), an adhesive filling recess (70) that opens in a direction parallel to an optical axis of an image pickup optical system (28) is defined by a center face (66), side faces (68) standing from both sides of the center face (66), an outer face (58), and an inner peripheral surface of the coil (52). The gate portion (72) is provided on the center face (66) of the adhesive filling recess (70). By filling the adhesive filling recess (74) with adhesive B, an outer peripheral portion of the lens holding member (30) and an inner peripheral portion of the coil (52) are bonded together, and the gate portion (72) is buried in the adhesive B.

Abstract: A variable power optical system composed of a first optical part, a second optical part, and a third optical part, with the first optical part being movable with respect to the second and third optical parts to change the focal length of the entire system. The first optical part is movably held between the second optical part and the third optical part. The first optical part moves in the direction perpendicular to the optical axis over a distance between the position on the optical system of the entire system and the position of retraction from the optical axis of the entire system.

Abstract: A variable power optical system composed of a first optical part (G1) for refraction, a second optical part (G2) for reflection or transmission, and a third optical part (G3) for refraction, with the first optical part being movable with respect to the second and third optical parts to change the focal length of the entire system, wherein the second optical part or the third optical part has a guide 4 which is in contact partly with the first optical part in such a way as to restrict its moving direction and the first optical part is movably held between the second optical part and the third optical part. This structure eliminates the necessity of separately forming the guide to move G1. The guide 4 is formed from a synthetic resin integrally with the stationary optical part (G3).

Abstract: A mounting structure for a plurality of lenses, wherein at least three lenses are arranged with their optical axes set to coincide with each other, the lenses located at both ends in the optical axis direction are provided with parts facing each other, and the mutually facing parts of the lenses are fixed to each other with an adhesive. The mounting structure, wherein all the lenses except the lenses located at both ends in the optical axis direction are fixed in the state of being clamped between the lenses located at both ends in the optical axis direction by shrinkage during curing of the adhesive.

Abstract: An arrangement structure of lenses includes two adjacent lenses, a first engagement surface formed at a surface where one lens out of the two lenses faces another lens, and a second engagement surface capable of engaging with the first engagement surface, which is formed in a surface where the another lens of the two lenses faces the one lens.

Abstract: A variable power optical system composed of a first optical part (G1) for refraction, a second optical part (G2) for reflection or transmission, and a third optical part (G3) for refraction, with the first optical part being movable with respect to the second and third optical parts to change the focal length of the entire system, wherein the second optical part or the third optical part has a guide 4 which is in contact partly with the first optical part in such a way as to restrict its moving direction and the first optical part is movably held between the second optical part and the third optical part. This structure eliminates the necessity of separately forming the guide to move G1. The guide 4 is formed from a synthetic resin integrally with the stationary optical part (G3).