Abstract: The present invention provides a lubricating base stock for internal combustion engine oil consisting essentially of an ester (A) obtained from an ethylene oxide adduct of diol having a neopentyl structure and a saturated aliphatic monocarboxylic acid having 4 to 12 carbon atoms, wherein the ethylene oxide adduct is obtained by adding ethylene oxide to a diol having a neopentyl structure in a ratio of 1 to 4 moles with respect to 1 mol of the diol, wherein the saturated aliphatic monocarboxylic acid is a linear carboxylic acid or a mixture of saturated aliphatic monocarboxylic acids comprising a linear aliphatic monocarboxylic acid in a ratio of at least 50 mol %, and wherein a dynamic viscosity of the ester (A) at 100° C. is 1 to 5 mm2/s, a viscosity index of the ester (A) is at least 140, and a total acid value of the ester (A) is 0.5 mg KOH/g or less.

Abstract: The invention discloses an optical apparatus comprises an optical member, manual operation means for manually driving the optical member, a driving motor for electrically driving the optical member, determination means for determining either manual drive by the manual operation means or electrical drive by the driving motor, connection means for transmitting drive force by the driving motor to the optical member with a predetermined connection torque, and control means for varying the connection torque of the connection means based on the result of determination by the determination means.

Abstract: The invention discloses an optical apparatus comprises an optical member, manual operation means for manually driving the optical member, a driving motor for electrically driving the optical member, determination means for determining either manual drive by the manual operation means or electrical drive by the driving motor, connection means for transmitting drive force by the driving motor to the optical member with a predetermined connection torque, and control means for varying the connection torque of the connection means based on the result of determination by the determination means.

Abstract: The present invention relates to an apparatus for controlling the lens position of a zoom lens. The zoom lens comprises a plurality of lens units movable along the optical axis for zooming, a focal length setting unit for setting the focal length of the zoom lens, an object distance setting unit for setting an object distance, a store containing a plurality of inherent coefficients and an arithmetic logic unit which specifies focal length information and object distance information as variables, and uses the coefficients in calculating a position to which a lens unit should move.

Abstract: A cam sleeve for axially moving a lens as it rotates about an optical axis is provided with a pair of camming grooves that depict the same locus. And, a holding member for the lens to be guided by a guide member is provided with a pair of pins corresponding to the pair of camming grooves. These pins engage in the pair of camming grooves to achieve good stability of movement of the lens when the cam sleeve rotates.

Abstract: A band having a back-of-the hand supporting member against which a back of the hand abuts is provided for a grip for holding a camera, and a transparent storing portion for storing a card with information is provided in the back-of-the hand supporting member.

Abstract: A regulator is provided which includes a housing, a seesaw-like operating member supported by the housing, a projection provided on the operating member, two movable members rotatably supported by the housing to push back the projection in a predetermined direction, a spring secured to these movable members to bias them in opposite directions, and limit member provided on the housing to determine the approach limit amount of the two movable members, a resistor provided on the housing, and a sliding brush coupled to the operating member to slide on the resistor.