Abstract: The invention relates to a lens mount assembly used for various kinds of optical apparatus such as photographic camera, motion picture handy camera and video camera, characterized in that the stationary sleeve which has usually been employed to support the cam sleeve and the movable sleeve is eliminated. To this end, the movable sleeve is formed with a plurality of keying grooves and there is provided a supporting framework comprising a plurality of keying levers adapted to be slidably engaged into the respective keying grooves. The cam sleeve is rotatably mounted around the movable sleeve so that the movable sleeve is operatively associated with the cam sleeve and guided by the keying levers to be moved in the direction of the optical axis.

Abstract: A zoom lens mount assembly in which a zooming cam frame is moved along the optical axis while rotating therearound and respective movable frames supporting an optical system are driven by such rotation and movement of the cam frame to effect a desired zooming. In another aspect there is provided a focussing cam frame adapted to be moved along the optical axis and to drive a movable frame provided with a focussing optical system and a program lens shutter.

Abstract: A constant speed driving apparatus comprises a starting means for starting a control unit, the first pulse-generating means for generating the first pulse signal with a predetermined frequency, a driving mechanism for driving a load, the second pulse-generating means for generating the second pulse signal corresponding to driving speed of the driving mechanism, and the control unit for controlling the driving mechanism on the basis of the first and second pulse signals.

Abstract: The present invention relates to a lens mount assembly for use in photographic camera, video camera and other various optical instruments. Usually, electric drive units for focussing and zooming, respectively, are gear-coupled to such lens mount assembly and drive torque from these drive units often causes deviation, deflection and eccentricity of the lens mount assembly, and additionally causes unreliable gear-coupling of the drive units and deteriorated image forming capability of the optical systems. The present invention provides a barrel supporting mechanism adapted to slidably support a front section of the lens mount assembly in order to overcome these problems. The present invention further provides the lens mount assembly with a simplified dust-proof mechanism utilizing a floating ring.

Abstract: In a camera whose camera body is extended along the optical axis, the camera body has a camera body gripping recess at a position where the index, middle, ring and little fingers ae placed when the operator holds the camera with the hand from below so that the operator can hold the camera stable with the hand for a long period of time.

Abstract: The present invention relates to a zoom lens mount assembly for use in optical apparatus such as photographic camera, video camera or the like. The zoom lens mount assembly of this type usually comprises a plurality of frames consisting of a stationary frame and movable frames assembled into a multilayered frame structure. The present invention provides a novel and improved zoom lens mount assembly in which the innermost layer is constructed from a plurality of frames into a single-layered structure and thereby an inner diameter of the lens mount assembly is dimensioned as largely as possible without making the lens mount assembly as a whole bulky. The present invention also permits the cam frame to be molded of synthetic resin material or the like and permits this cam frame to be mounted in a bayonet fashion.