Abstract: Two cam pins of the variable magnification lens group and the aberration correction lens group are guided by two side walls of one cam groove. Thus, two cam grooves can deal with three movable lens groups, and there is no need to provide three cam grooves. Consequently, the cam cylinder can be short, and thereby the zoom lens apparatus can be compact. A spring applies force to the two cam pins to separate from one another, so that the cam pins can be pressed against the side walls.

Abstract: A zoom lens apparatus which is superior in sound insulating and dust-proof properties and is easy to handle in transportation, storage and so forth. A lens system including a zoom lens set, a focusing lens set and an iris disposed on a single optic axis, a zoom lens driving section composed of a motor, a ball screw, a lens holding member, a nut member and so forth for driving the zoom lens, a focusing lens driving section composed of a guide rod, a lens holding member, a movable coil, an outer yoke, magnets and so forth for driving the focusing lens, and an iris motor for opening and closing the iris are accommodated in the housing having a substantially rectangular outer profile.

Abstract: An optical assembly includes a lens assembly having a lens barrel for supporting a lens along an optical axis, an optical base having an opening aligned with the optical axis, and a plurality of ramps and a corresponding plurality of reference locators circumferentially arranged around the lens assembly and the opening in the optical base in order to slide against one another. A retaining element biases the lens assembly against the optical base with the ramps and the reference locators likewise biased therebetween against each other. Consequently, the ramps and reference locators provide an arrangement for focusing the lens assembly. The optical assembly also includes a factory focus tab attached to the lens assembly and accessible during the manufacturing operation for focusing the lens assembly by moving the ramps against the reference locators, and a focus adjuster assembly accessible during user focus for focusing the lens assembly by moving the ramps against the reference locators.

Abstract: A zoom lens barrel includes a device which accurately suppresses image blur through motion compensation while suppressing the rattling of internal components and eliminates the effects from reaction forces arising while driving a motion compensation lens group. The zoom lens barrel includes at least two lens groups which move during zooming and a motion compensation lens group which is driven to compensate for image blurring motion. A mounting device supports the lens barrel in relation to an optical device with a fixed tube attached to the mounting device. A frame body is also affixed in the fixed tube and a drive device which drives the motion compensation lens group is mounted in the frame body.

Abstract: A lens position adjusting apparatus for adjusting an axial position of a rearmost lens group of a plurality of lens groups provided in a focal length variable lens upon assembly of the focal length variable lens is provided. The lens position adjusting apparatus includes a lens frame, a lens frame holder and an engagement tooth array portion. The lens frame holds the rearmost lens group. The lens frame holder engages with the lens frame through a threaded engagement. The engagement tooth array portion is formed along a rear end of the lens frame. The engagement tooth array portion consists of a plurality of engaging teeth. Each of the engaging teeth extends in a direction substantially parallel to an optical axis facing towards a rear of the focal length variable lens.

Abstract: A first zoom lens group, a second zoom lens group, a third zoom lens group and a fourth zoom lens group are arranged on an optical axis in that order from an object side. The first zoom lens group has a negative lens and a positive lens arranged in that order from the object side, the first zoom lens group as a whole acting as a zoom lens group having a positive focal length. The second zoom lens group has a negative lens and a positive lens arranged from the object side in that order, the second zoom lens group as a whole acting as a zoom lens group having a negative focal length. The third zoom lens group has a double concave lens and a double convex lens arranged in that order from the object side, the third zoom lens group as a whole acting as a zoom lens group having a positive focal length, the third zoom lens group being provided with a diaphragm.

Abstract: A zoom lens barrel is provided having a plurality of lens groups which are moved with respect to one another along a predetermined path. The zoom lens barrel comprises a driving barrel which rotates about an optical axis of the plurality of lens groups and at least three telescoping barrels which are moved in the direction of the optical axis by rotation of the driving barrel. Each telescoping barrel which is mounted on an inner periphery of another telescoping barrel of the telescoping barrels, travels a greater distance along the optical axis direction than the another telescoping barrel. A lens group driving mechanism is provided for moving the plurality of lens groups in the optical axis direction by movement of the at least three telescoping barrels in the optical axis direction.

Abstract: A zoom lens assembly includes a stationary lens barrel and a rotatable cam ring which is supported on the stationary lens barrel for movement in the direction of the optical axis while being rotated, and which includes at least two cam grooves. The zoom lens include first and third lens groups which are both moveable by one of the two cam grooves in the direction of the optical axis. A second lens group movable, by a second of the two cam grooves in the direction of the optical axis is also provided, as well as a focusing mechanism, for moving the second lens group to a position which is determined by focal length data derived from actual positions of the first, second, and third lens groups and object distance data detected by an object distance measuring device. A method of controlling focusing of the zoom lens includes correcting an amount of deviation from focus caused by a zooming operation, by moving the focusing lens group.

Abstract: A camera lens barrel for a camera includes first, second, third and fourth lens groups with a diaphragm located between the second and third lens groups. The second and third lens groups are connected, while the first, third and fourth lens groups can move relative to each other along the optical axis of the camera lens barrel. A diaphragm driver is positioned radially outside of the second lens group, while a lens shift driver device, including the horizontal and vertical lens shift drivers, is positioned radially outside of the third lens group. The diaphragm driver and the lens shift driver device are connected to a control unit via a flexible printed circuit. A power transmission extends from the diaphragm driver to the fourth lens group. The power transmission is connected to the diaphragm driver via a pin. When the pin is rotated, the angular rotation of a pin is transmitted to the fourth lens group to focus the camera lens barrel. Thus, the overall diameter of the camera lens barrel is reduced.

Abstract: A zoom lens barrel is provided including a cam ring which is threadedly engaged to a female helicoid formed in a stationary barrel, a linear movement guide member that is rotatable relative to the cam ring and movable in an optical axis direction together with the cam ring, and movable lens groups, including first, second and third lens groups that are guided in the optical axis direction by the linear movement guide member. The zoom lens barrel further includes a cut-away portion formed at one end of a linear movement guide groove and inclined at an angle identical to the helicoids between the cam ring and the annular member.

Abstract: A compact, wide-angle, fast zoom lens system of high optical performance which enables photography in the range of from the wide-angle region to the telephoto region. The zoom lens system has a 1-st lens unit (G1) of positive refractive power, a 2-nd lens unit (G2) of negative refractive power, a 3-rd lens unit (G3) of positive refractive power, a 4-th lens unit (G4) of positive refractive power, and a 5-th lens unit (G5) of positive refractive power. When zooming from the wide end toward the tele end is effected, the 1-st lens unit (G1), the 2-nd lens unit (G2), the 3-rd lens unit (G3) and the 4-th lens unit (G4) are movable, while the 5-th lens unit (G5) is fixed.

Abstract: When rotational force of a zooming motor is transmitted to a driving gear, a main moving frame in a lens body tube is moved along an optical axis while the main moving frame is rotated. Thus, a moved frame is moved along the optical axis and a cam frame is rotated while the cam frame is moved along the optical axis. While a zooming optical system is moved from a wide angle position to a storing position, a moving frame for a second lens group is rotated by rotational force of the cam frame while the moving frame for the second lens group is moved along the optical axis. Further, a moving frame for a third lens group is moved along the optical axis while no moving frame for the third lens group is rotated. A converter lens is inserted into an optical path of an effective light beam from an escaping position by a relative rotating operation of these two moving frames. Accordingly, it is possible to provide an optical system having a super short focal length which cannot be obtained within a zooming region.

Abstract: There is disclosed a zoom lens barrel of inner focusing type, simplified in structure by the use of a surface wave motor. There are provided two biasing members of different biasing forces, in such a manner that the stator member of the surface wave motor can rotate with respect to the fixed tube member and the movable member of the surface wave motor rotates integrally with the stator member in the zooming operation. Such structure allows to dispense with a mechanical clutch for selecting the focusing or zooming operation.

Abstract: A zoom lens barrel is provided including a cam ring which is threadedly engaged to a female helicoid formed in a stationary barrel, a linear movement guide member that is rotatable relative to the cam ring and movable in an optical axis direction together with the cam ring, and movable lens groups, including first, second and third lens groups that are guided in the optical axis direction by the linear movement guide member. The zoom lens barrel further includes a female helicoid formed on an inner peripheral surface of the cam ring to engage with a male helicoid of a first lens frame which holds the first lens group and a plurality of cam grooves formed on the cam ring to drive lens groups behind the first lens group.

Abstract: A zoom lens having a plurality of movable lens groups, and an apparatus which is used to adjust the position of the rearmost lens group of the plurality of movable lens groups in the optical axis direction upon assembly of the zoom lens, so that a focal point of the zoom lens does not deviate upon zooming.

Abstract: A zoom camera lens which is particularly compact, has a small number of elements and is capable of good performance at relatively wide aperture has a front negative lens group, a middle positive lens group and a rear negative lens group. The rear negative lens group has a focal length not more than 1.25 times the focal length of the middle positive lens group. Preferably, the lens has seven or eight elements and is designed without the use of aspheres.

Abstract: A zoom lens assembly includes a stationary lens barrel and a rotatable cam ring which is supported on the stationary lens barrel for movement in the direction of the optical axis while being rotated, and which includes at least two cam grooves. The zoom lens include first and third lens groups which are both movable by one of the two cam grooves in the direction of the optical axis. A second lens group movable, by a second of the two cam grooves in the direction of the optical axis is also provided, as well as a focusing mechanism, for moving the second lens group to a position which is determined by focal length data derived from actual positions of the first, second, and third lens groups and object distance data detected by an object distance measuring device. A method of controlling focusing of the zoom lens includes correcting an amount of deviation from focus caused by a zooming operation, by moving the focusing lens group.

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 great aperture zoom lens has, in succession from the object side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having positive refractive power. The second lens unit has, in succession from the object side, a negative lens component, a negative lens component, a positive lens component and a negative lens component. In case of the magnification change from the wide angle end to the telephoto end, the first lens unit, the third lens unit and the fourth lens unit are moved toward the object side. The zoom lens satisfies various predetermined conditions.

Abstract: A lens barrel according to the present invention includes a first frame member which is moved in the direction of the optical axis with respect to a fixed member due to a predetermined operation; a second frame member which is moved in the direction of the optical axis with respect to the fixed member and the first frame member due to a predetermined operation; and a flare diaphragm engaging to the second frame member and interposed between the first frame member and the fixed member, wherein the flare diaphragm is engaged by one of the fixed member and the first frame member as a result of the movement of the second frame member in the direction of the optical axis due to the predetermined operation, so that the flare diaphragm is moved in the direction of the optical axis with respect to the second frame member.

Abstract: In a zoom lens system having a plurality of lens units including a focusing lens unit movable during zooming and having the zooming and focusing functions, when a predetermined movement locus for zooming is expressed with the angle of rotation of a rotatable lens barrel for prescribing the amount of movement of the lens units in the direction of the optical axis thereof as a variable, the movement locus of the focusing lens unit is formed by the combination of a focus cam and a zoom compensation cam, and the movement locus of the movable non-focusing lens units which are not concerned in focusing is formed by the combination of the zoom compensation cam and a zoom cam corresponding to each non-focusing lens unit.

Abstract: A projection lens apparatus for a rear projection television. The projection lens apparatus includes a first lens in which the negative power of the lens gradually increases from the central portion of the lens, having almost no power, to the peripheral portion, a second lens having a strong positive power, a third lens in which the positive power of the lens gradually increases from the central portion, having almost no power, to the peripheral portion, a fourth lens having a positive power at the central portion and a negative power at the peripheral portion and a fifth lens having a strong negative power, wherein the first to fifth lenses are sequentially arranged along an optical axis toward a cathode ray tube from a screen. The various lenses perform different functions. Accordingly, the projection distance and the size of the lens are reduced, thereby reducing the size of the system.

Abstract: A zoom finder is provided and includes a lens group for producing a field flattening effect for correcting a curvature of field. The zoom finder includes an objective optical system of a positive power having a first lens group of negative power, a second lens group of positive power, a third lens group of positive power, and an eyepiece optical system of positive power through which an image formed by the objective optical system is observed. The first lens group, the second lens group, the third lens group and the eyepiece optical systems are arranged in this order from an object side. The second lens group of the objective optical system is movable in an optical axis direction to vary the power, and the first and second lens groups are movable in association with each other in order to keep a constant diopter.

Abstract: A camera of the present invention comprises a stationary frame adjustable in position with respect to a camera body in the direction of an optical axis; a cam frame disposed around an outer circumference of the stationary frame to be rotatable about the optical axis and movable in a direction of the optical axis with respect to the stationary frame; a finder optical system provided on the camera body; and a finder optical system driving cam provided integrally with the cam frame for driving the finder optical system. In-focus position adjustment of a photographing optical system of the camera is performed during assembly by moving only the stationary frame in the direction of the optical axis, while the cam frame is kept immobile with respect to the camera body.

Abstract: A lens assembly has zooming and focusing capabilities and a plurality of lens groups. The lens assembly has a region ranging from an infinity position to a closest available position and over which some of the lens groups used for focusing purpose are driven in an axial direction parallel to an optical axis of the lens assembly in a distance variable with a change in focal length resulting from a zooming operation.

Abstract: A zoom lens system comprising, in the order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a positive refractive power and a fifth lens unit having a negative refractive power, adapted so as to vary the focal length by moving said first through fourth lens units independently while keeping said fifth lens unit fixed, and adapted so as to perform focusing by moving at least one of said second through fifth lens units. This zoom lens system has a high vari-focal ratio, a wide field angle, a compact size, and optical performance stabilized regardless of zooming and focusing.

Abstract: A zoom tracking apparatus of a focusing lens in which a position of a focusing lens is controlled to an in-focus position so as to follow a motion of a zoom lens. The apparatus includes components for wobbling the focusing lens or an image pickup device in the front and back directions; and components for controlling front and back wobbling amounts of the focusing lens or the image pickup device, wherein the front and back wobbling amounts of the focusing lens or the image pickup device are changed in accordance with a relation between the position of the zoom lens and the in-focus position of the focusing lens.

Abstract: A zoom finder is provided which includes an objective optical system of a positive power having a first lens group of negative power, a second lens group of positive power, a third lens group of positive power, and an eye piece optical system of a positive power through which an image formed by the objective optical system is observed. The first lens group, the second lens group, the third lens group and the eye piece object system are arranged in this order from an object side. The second lens group of the objective optical system is movable in an optical axis direction to vary the power, and the first and second lens groups are movable in association with each other to keep a constant diopter.

Abstract: A lens driving apparatus for moving a plurality of lens groups, in an optical axis direction, to change the spatial distance therebetween, including a supporting cylinder which is secured to an immovable portion of a lens barrel, a cam ring which is rotatably fitted on the supporting cylinder, at least two inner lens moving frames which are provided in the supporting cylinder so as to move in the optical axis direction, guide grooves which are formed on the supporting cylinder to guide the lens moving frames in the optical axis direction, cam grooves which are formed on the cam ring to move the lens moving frames along therewith, and cam followers which are secured to the inner lens moving frames and which extend through the corresponding guide grooves to be fitted into the corresponding cam grooves.

Abstract: Optical apparatus comprises an optical element and a moving mechanism having two members arranged to move the optical element in the direction of an optical axis thereof by moving one of the two members in the direction of the optical axis relative to the other while rotating said two members relative to each other. The two members include a male helicoid member having a male helicoid screw and a female helicoid member having a female helicoid screw arrangement in screw engagement with the male helicoid screw, the female helicoid screw arrangement providing only a single screw thread peripherally interiorly of the female helicoid member along an axis parallel to the optical axis.

Abstract: An initial focusing mechanism for a zoom lens system adapted to achieve the initial focusing by moving a variator lens and a compensator lens along an optical axis with respect to a focusing lens. A cylinder cam is slidably movable within a barrel along the optical axis. The cylinder cam carries the variator lens and the compensator lens and is rotatable with respect to the barrel during zooming so that the variator lens and compensator lens can be moved along the optical axis maintaining a given inter-lens optical relationship. A slide element is provided for moving the cylinder cam along the optical axis and locking the cylinder cam at a selected position relative to the barrel. For initial focusing, the cylinder cam is slidably moved along the optical axis which adjustably moves the variator lens and the compensator lens relative to the focusing lens. Upon completion of this adjustment, the cylinder cam is fixed to the barrel.

Abstract: A zoom lens device is disclosed which is ideal for use in a video camera. In the zoom lens device, a zoom ring is provided directly in the rear end of a cam barrel without using any connecting pins, and the zoom ring is exposed out from a fixed barrel so that it can be operated from externally. For this reason, there is eliminated the need for provision of an escape groove for the connecting pins in the fixed barrel and thus the angles of cam grooves can be increased up to a limit beyond which the cam grooves may interfere with each other. As a result of this, a zoom lens device which is compact and is of a high magnification can be realized.

Abstract: A zoom lens system comprising, in order from an enlargement side, a first lens unit of a positive power, a second lens unit of a positive power, a third lens unit of a negative power, and a fourth lens unit of a positive power. During a magnification varying operation from a longest focal length condition to a shortest focal length condition, the first lens unit, the third lens unit and the fourth lens unit are movable simply from the enlargement side to a reduction side. The second lens unit is closest to the third lens unit in the longest focal length condition, and closest to the first lens unit in the shortest focal length condition. This zoom lens system satisfies the following conditions:42=<f.sub.L /f.sub.I =<54=<f.sub.L /.vertline.f.sub.III .vertline.=<13where f.sub.L is a focal length of the entire system in the longest focal length condition, f.sub.I is a focal length of the first lens unit, and f.sub.III is a focal length of the third lens unit.