Abstract: A zoom optical system having a lens group I including two single lenses or one lens component, an aperture stop, and a lens group A disposed between the lens group I and the aperture stop, including a lens component made up of a positive lens LA and a negative lens LB that are cemented together, and having a negative refracting power as a whole. The distance between the lens group I and the lens group A on the optical axis changes for zooming, and the lens component has an aspheric cemented surface. When the shape of the aspheric surface is expressed by a certain equation, the shape of the air-contact surface of the positive lens LA and its aspheric components etc. satisfy conditional expressions (3a) and (3b).

Abstract: A zoom lens includes, in order from the object side, a first lens unit with negative power, a second lens unit with positive power, a third lens unit with positive power, and a fourth lens unit. When the magnification of the zoom lens is changed in the range from a wide-angle position to a telephoto position, spacing between the first lens unit and the second lens unit is narrowed and spacing between the second lens unit and the third lens unit is widened. An aperture stop moved integrally with the second lens unit is interposed between the most image-side lens element of the first lens unit and the most image-side lens element of the second lens unit. The first lens unit has, in order from the object side, a negative lens element and a positive lens element and satisfies the following conditions: 0.15<?1MF/?1MR<1.0 ?3.0<?1PF/?1PR<?1.

Abstract: A zoom optical system having a lens group I including two single lenses or one lens component, an aperture stop, and a lens group A disposed between the lens group I and the aperture stop, including a lens component made up of a positive lens LA and a negative lens LB that are cemented together, and having a negative refracting power as a whole. The distance between the lens group I and the lens group A on the optical axis changes for zooming, and the lens component has an aspheric cemented surface. When the shape of the aspheric surface is expressed by a certain equation, the shape of the air-contact surface of the positive lens LA and its aspheric components etc. satisfy conditional expressions (3a) and (3b).

Abstract: The invention relates to a stereo imager that is reduced in the number of members, favorable in view of cost and less susceptible to variations from optical system to optical system. The stereo imager comprises a single image pickup device 4 and a stereo imaging optical system including bending member 21L, 21R, 22L and 22R for bending parallactic light beams from a subject and adapted to form on the single image pickup device 4 at least two parallactic images having mutual parallaxes. The stereo imaging optical system comprises at least one optical member 3 located in front of the single image pickup device 4 and adapted to receive light beams forming at least two parallactic images and have the same optical action or function with respect to each light beam.

Abstract: A zoom lens includes, in order from the object side, a first lens unit with negative power, a second lens unit with positive power, a third lens unit with positive power, and a fourth lens unit. When the magnification of the zoom lens is changed in the range from a wide-angle position to a telephoto position, spacing between the first lens unit and the second lens unit is narrowed and spacing between the second lens unit and the third lens unit is widened. An aperture stop moved integrally with the second lens unit is interposed between the most image-side lens element of the first lens unit and the most image-side lens element of the second lens unit. The first lens unit has, in order from the object side, a negative lens element and a positive lens element and satisfies the following conditions: 0.15<?IMF/?IMR<1.0 ?3.0<?IPF/?IPR<?1.

Abstract: The invention relates to a superwide-angle lens optical system having a long back-focus lens arrangement and comprising a relay lens group. The optical system is constructed of, in order from an object side thereof, an objective lens group Ob having positive refracting power, a primary image-formation plane formed by the objective lens group Ob and a relay lens group R1 having positive refracting power. A field stop FS is positioned at or near the primary image-formation plane, and condition (1-1) is satisfied. h/fo>1.8??(1-1) Here fo is the focal length of the objective lens group Ob, and h is the diameter of an image circle on the primary image-formation plane.

Abstract: The invention relates to a stereo imager that is reduced in the number of members, favorable in view of cost and less susceptible to variations from optical system to optical system. The stereo imager comprises a single image pickup device 4 and a stereo imaging optical system including bending member 21L, 21R, 22L and 22R for bending parallactic light beams from a subject and adapted to form on the single image pickup device 4 at least two parallactic images having mutual parallaxes. The stereo imaging optical system comprises at least one optical member 3 located in front of the single image pickup device 4 and adapted to receive light beams forming at least two parallactic images and have the same optical action or function with respect to each light beam.

Abstract: The invention relates to a superwide-angle lens optical system having a long back-focus lens arrangement and comprising a relay lens group. The optical system is constructed of, in order from an object side thereof, an objective lens group Ob having positive refracting power, a primary image-formation plane formed by the objective lens group Ob and a relay lens group R1 having positive refracting power. A field stop FS is positioned at or near the primary image-formation plane, and condition (1-1) is satisfied. h/fo>1.8??(1-1) Here fo is the focal length of the objective lens group Ob, and h is the diameter of an image circle on the primary image-formation plane.

Abstract: A socket for electrical parts is provided with a socket body for accommodating the electrical part. A plurality of contact pins is arranged to the socket body so that a central side contact pin is arranged to the socket body to contact a center side terminal of the electrical part and a peripheral side contact pin is arranged to the socket body to contact a peripheral side terminal of the electrical part. A press unit is arranged to press an upper surface of the peripheral portion towards a bottom surface side thereof so that, if the electrical part is warped, it becomes possible to securely hold the electrical part by the press unit.

Abstract: A socket for an electrical part includes a socket body to which an electrical part having terminals are mounted, a number of contact pins arranged to the socket body so as to be contacted to or separated from the terminals of the electrical part, an operation member mounted to the socket body to be reciprocally movable with respect to the socket body, an open/close unit mounted to the socket body to be opened or closed in accordance with the reciprocal motion of the operation member and to press the electrical part when closed, and a closing speed reduction feature arranged for the open/close unit so as to reduce a closing speed thereof when the open/close unit is rotated in a closing direction thereof.

Abstract: A socket for electrical parts is provided with a socket body for accommodating the electrical part. A plurality of contact pins is arranged to the socket body so that a central side contact pin is arranged to the socket body to contact a center side terminal of the electrical part and a peripheral side contact pin is arranged to the socket body to contact a peripheral side terminal of the electrical part. A press unit is arranged to press an upper surface of the peripheral portion towards a bottom surface side thereof so that, if the electrical part is warped, it becomes possible to securely hold the electrical part by the press unit.