Abstract: An image formation optical unit is provided. In the image formation optical unit, a first shaft formed with a guide shaft and a drive shaft and a second shaft formed with a guide shaft and a drive shaft are disposed side by side so as to extend in parallel with a second optical axis direction. A free space is thus provided in the center and further two motors and are disposed in a free space at the rear of a prism, thereby making it possible to further reduce the dimensions in the height direction.

Abstract: Sliders of a movable lens holder are provided with cam followers respectively. Each of the sliders engages with a guide opening formed in a lens frame so that the movable lens holder is allowed to move in an optical-axis direction. The movable lens holder is retained in a cam barrel provided with cam grooves, which are formed so as to shift their positions in the optical-axis direction and in a rotational direction of the cam barrel. The cam followers engage with the cam grooves respectively.

Abstract: Sliders of a movable lens holder are provided with cam followers respectively. Each of the sliders engages with a guide opening formed in a lens frame so that the movable lens holder is allowed to move in an optical-axis direction. The movable lens holder is retained in a cam barrel provided with cam grooves, which are formed so as to shift their positions in the optical-axis direction and in a rotational direction of the cam barrel. The cam followers engage with the cam grooves respectively.

Abstract: A zoom lens device includes a zoom optical system, in which front, middle and rear lens groups are set at one focal length between a wide-angle end where a focal length is short and a telephoto end where the focal length is long. Lens barrels move in first and second regions to move the front, middle and rear lens groups along an optical axis. The lens barrels, when in the first region, focus the zoom optical system with a predetermined focal length kept by maintaining an interval between the front and middle lens groups, and when in the second region, change the focal length of the zoom optical system. A combination of a cam follower pin and a cam groove effects focusing by moving the middle lens group relative to the front lens group along the optical axis when the lens barrels are in the second region.

Abstract: A zoom lens device includes a zoom optical system, in which front, middle and rear lens groups are set at one focal length between a wide-angle end where a focal length is short and a telephoto end where the focal length is long. Lens barrels move in first and second regions to move the front, middle and rear lens groups along an optical axis. The lens barrels, when in the first region, focus the zoom optical system with a predetermined focal length kept by maintaining an interval between the front and middle lens groups, and when in the second region, change the focal length of the zoom optical system. A combination of a cam follower pin and a cam groove effects focusing by moving the middle lens group relative to the front lens group along the optical axis when the lens barrels are in the second region.

Abstract: A moving mechanism for a cylinder is provided, in which a projection and groove are engaged by relative movement different from that of a helicoid mechanism and movement of inner and outer cylinders relative to each other can be freely set. In the moving mechanism, a first helicoid thread is helically formed on the inner surface of an intermediate cylinder, a second helicoid thread that threadably engages with the first helicoid thread is helically formed on the outer surface of a movable cylinder, and the intermediate cylinder is rotated so the movable cylinder is moved relative to the intermediate cylinder. A projection is formed on the outer surface of the movable cylinder and a groove engageable with the projection is formed in the inner surface of the intermediate cylinder. In a range where the first and second helicoid threads threadably engage with each other upon relative movement of the movable cylinder, the groove is formed parallel to the first helicoid thread.

Abstract: A lens driving apparatus includes an intermediate barrel expandable and collapsible in an optical axis direction, for moving a rear lens group in the optical axis direction along with expanding and collapsing; a movable barrel, concentric with the intermediate barrel, expandable and collapsible with respect to the intermediate barrel along with the expanding and collapsing of the intermediate barrel, for moving a front lens group in the optical axis direction when expanding from the intermediate barrel; and a click ball for holding the front lens group when the movable barrel collapses, so as to move the front lens group together with the intermediate barrel. As a consequence, when the movable barrel collapses, the front lens group can be held and moved together with the intermediate barrel so the focus can be adjusted appropriately, and the apparatus can be made smaller at a lower cost.

Abstract: A barrier opening and closing apparatus for opening and closing a barrier according to a rotation of a lens barrel containing an optical lens system includes a ring member rotatable about an optical axis of the optical lens system and opening and closing the barrier according to rotation of the ring member. The ring member has rotational force transmitting parts extending rearward, parallel to the optical axis and engaging the lens barrel. The ring member is directly rotated by the rotational force transmitting parts engaged with the lens barrel, to open and close the barrier so the cost of the apparatus can be reduced.

Abstract: A moving mechanism for a cylinder is provided, in which a projection and groove are engaged by relative movement different from that of a helicoid mechanism and movement of inner and outer cylinders relative to each other can be freely set. In the moving mechanism, a first helicoid thread is helically formed on the inner surface of an intermediate cylinder, a second helicoid thread that threadably engages with the first helicoid thread is helically formed on the outer surface of a movable cylinder, and the intermediate cylinder is rotated so the movable cylinder is moved relative to the intermediate cylinder. A projection is formed on the outer surface of the movable cylinder and a groove engageable with the projection is formed in the inner surface of the intermediate cylinder. In a range where the first and second helicoid threads threadably engage with each other upon relative movement of the movable cylinder, the groove is formed parallel to the first helicoid thread.

Abstract: A barrier opening and closing apparatus for opening and closing a barrier according to a rotation of a lens barrel containing an optical lens system comprises a ring member disposed rotatable about an optical axis of the optical lens system and adapted to open and close the barrier according to a rotation thereof, whereas the ring member forms a plurality of rotational force transmitting parts extending rearward therefrom in parallel to the optical axis so as to be engaged with the lens barrel. The ring member is directly rotated by way of the plurality of rotational force transmitting parts engaged with the lens barrel, so as to open and close the barrier, whereby the cost of apparatus can be cut down.

Abstract: In a zoom lens barrel, a driving barrel is rotated when magnification is changed. Upon this rotation, a moving barrel having a front lens group and a shutter block is moved in an optical axis direction. A straight guide barrel for preventing the moving barrel from rotating is rotatably supported in the driving barrel. Further, a cam barrel is rotatably supported in the straight guide barrel. The rotation of the driving barrel is transmitted to rotate the cam barrel. A rear-lens-group holder contained in the cam barrel is moved in the optical axis direction owing to workings of the cam barrel and the straight guide barrel. The shutter block is provided with a projection for changing a maximum aperture size of the shutter blades. An inner surface of the cam barrel is provided with a cam groove obliquely formed in a rotational direction around the optical axis. The cam groove engages with the projection when the shutter block enters the cam barrel, and regulates the maximum aperture size of the shutter blades.

Abstract: A zoom lens barrel includes first and second lens groups arranged along an optical axis. A first drive mechanism moves the first lens group only in the direction of the optical axis for focusing. A second drive mechanism moves both the first and second lens groups in the direction of the optical axis for zooming. A rotary barrel which is rotated by the second drive mechanism is provided with a cam groove which guides the second lens group in response to rotation of the rotary lens barrel during zooming. A cam follower is provided on the lens holder of the second lens group and is in engagement with the cam groove. The cam groove consists of alternately formed zooming groove portions and flange back adjustment groove portions, and flange back adjustment is carried out by rotating the rotary barrel with the cam follower in engagement with one of the flange back adjustment groove portions.

Abstract: A lens barrel for a zoom lens includes first and second lens groups arranged in the direction of an optical axis. A first rotary barrel is rotatable about the optical axis and is rotated to move the first lens group in the direction of the optical axis, and a second rotary barrel is provided coaxially with the first rotary barrel. A guide groove is provided on the second rotary barrel and guides the second lens group to move it in the direction of the optical axis in response to rotation of the second rotary barrel. A rotation transmission mechanism is disposed between the first and second rotary barrels to be able to engage to rotate both the first and second rotary barrels, thereby zooming the zoom lens, and to be able to disengage to rotate only one of the first and second rotary barrels through a predetermined angle range with the other held stationary so that focusing the zoom lens can be effected by rotating said one rotary barrel within the predetermined angle range.

Abstract: A zoom lens driving mechanism is disclosed that is adapted to rotate a first driving lens barrel and a second driving lens barrel relative to each other and thereby to move a movable lens barrel back and forth in parallel to an optical axis. More specifically, a linearly movable member that is provided to guide a linear movement of the movable lens barrel relative to the second driving lens barrel, is moved back and forth under a guidance by a leading groove formed in the first driving lens barrel. With such a unique arrangement, no part is required to support the linearly movable member, and therefore, any apprehension about the strength of a part as well as a flare phenomenon can be avoided.

Abstract: A helicoid structure is disclosed that includes a male helicoid provided on an inner barrel and a female helicoid provided on an outer barrel. The female helicoid includes long female crests having engagement ends positioned near a forward end of the outer barrel and short female crests having engagement ends positioned further from the forward end of the outer barrel. At least one of the short female crests is connected to an adjacent long female crest by a guiding crest respectively formed along a plane extending orthogonally to an axis of the outer barrel. When the inner barrel having the male helicoid is rotated relative to the outer barrel having the female helicoid in order to assemble the inner barrel into the outer barrel, the engagement ends of the male helicoid crests are guided by the guiding crests so that the inner barrel may be rotated without any linear movement relative to the outer barrel.

Abstract: A helicoid-structure characterized by width-enlarged parts formed by partially widening the respective troughs, which allow the crests to be linearly moved with the increment per unit rotational angle different from the increment per unit rotational angle with which the crests are linearly moved when they are guided by the troughs alone. In a specific embodiment, a stationary lens barrel is formed in its inner peripheral surface with three troughs, each describing a helical curve of appropriate length, on one hand, and a movable lens barrel is formed on its outer peripheral surface with three crests corresponding to the respective troughs each describing a helical curve of appropriate length, on the other hand. The respective troughs are partially widened transversely of the respective helical curves to form width-enlarged parts and a length of each width-enlarged part is dimensioned to be substantially equal to a length of each crest.

Abstract: A driving mechanism is disclosed for photographic lens having a stationary lens barrel, a first driving lens barrel adapted to be rotated and moved back and forth relative to the stationary lens barrel, a second driving lens barrel operatively associated with the first driving lens barrel by the aid of a rotation transmitting structure so as to be rotated and moved back and forth relative to the first driving lens barrel, and a movable lens barrel holding a front lens group and being movable back and forth relative to the second driving lens barrel. With this arrangement, power varying or focusing is achieved with a relatively small-sized lens barrel assembly by moving a rear lens group back and forth under a regulating action of the second driving lens barrel. The first driving lens barrel is rotatably received by and operatively associated with the stationary lens barrel through helicoids formed on these two lens barrels.

Abstract: A photographic camera has a camera back body on which are mounted an electronic circuit assembly including an external display system and the like and a pressure plate which is movable in the direction of the optical axis of a taking lens of the camera and supports the back side of a film loaded in the camera. A spring structure for urging the pressure plate toward the film includes a pair of torsion springs each having a linear shaft portion and a plurality of abutment portions extending substantially perpendicular to the shaft portion. The springs are disposed between the pressure plate and the camera back body so that the shaft portions of the respective torsion springs extend along opposite side edges of the pressure plate and a part of the abutment portions abuts against the pressure plate with the other abutment portions in abutment against a fixed portion on the camera back body.

Abstract: A camera with a variable focus lens device, in which a lens position detecting device detects the focal length of the photographing lens from the amount of movement of a movable member that is capable of being rectilinearly advanced and retracted along the optical axis of the photographing lens, in order to provide an autofocusing function to accurately focus upon an object. Thus, the focal length can be detected in a simplified manner, and the influence of errors during assembly of the components of a photographing lens driving system can be minimized. A flare preventing mask effectively prevents flare occurrence in correspondence to variations in the position of the photographing lens. The lens retaining structure simplifies the assembly of the front lens group into a movable lens mount, and reduces the size and weight of the camera.

Abstract: A camera accommodates a main lamp for electronic flashing and an auxiliary lamp for preventing a red-eye phenomenon.The auxiliary lamp for preventing a red-eye phenomenon is directly held by a holder composed of a material of a color having a light reflecting effect such as white. Since the holder also function as a reflecting plate, the structure of the camera is simplified. A transparent cover is integrally provided with at least a finder window, an electronic flash lamp window at which the main lamp for electronic flashing is disposed, and an auxiliary lamp window at which the auxiliary lamp is disposed. The transparent cover is attached to the camera as a part of a case, thereby simplifying the structure of the camera. The auxiliary lamp is preferably disposed in the area between the lens barrel at the central portion and the main lamp. Thus, the arrangement of parts in the camera avoiding waste is realized.