Abstract: An objective lens system for optical pickups performing at least one of reading and writing of information by condensing a luminous flux from a light source on an information recording medium, has the following two lens elements from a light source side: a first lens element having a first surface convex to the light source side and a second surface convex to the light source side; and a second lens element having a third surface convex to the light source side and a plane fourth surface, wherein the first surface is an aspherical surface.

Abstract: A scanning optical system has an object side lens unit for condensing light from an object, a mirror for performing a main scan to read the image of the object by deflecting the light transmitted through the object side lens and an image side lens unit for forming an image on the image sensing surface using both the extra-axial light and axial light in a subscan direction deflected by the mirror. The scanning optical system satisfies the predetermined condition defined by lenses of Abbe number.

Abstract: An objective lens system for optical pickups performing at least one of reading and writing of information by condensing a luminous flux from a light source on an information recording medium, has the following two lens elements from a light source side: a first lens element having a first surface convex to the light source side and a second surface convex to the light source side; and a second lens element having a third surface convex to the light source side and a plane fourth surface, wherein the first surface is an aspherical surface.

Abstract: A zoom optical system has a focus adjusting unit that performs focusing for an object by moving along an optical axis thereof and a magnification adjusting unit that corrects a change in optical magnification caused by the focusing by moving along an optical axis thereof.

Abstract: A zoom lens system has a first lens unit having a positive optical power, a second lens unit having a negative optical power, a third lens unit, and a fourth lens unit. In this zoom lens system, a zooming operation is performed by varying distances between the first, second, third, and fourth lens units, and the following condition is fulfilled: 0.4<|&phgr;2/&phgr;W|<0.8 where &phgr;2 represents an optical power of the second lens unit; and &phgr;W represents an optical power of the entire zoom lens system at the wide-angle end.

Abstract: A scanning optical system has an object side lens unit for condensing light from an object, a mirror for performing a main scan to read the image of the object by deflecting the light transmitted through the object side lens and an image side lens unit for forming an image on the image sensing surface using both the extra-axial light and axial light in a subscan direction deflected by the mirror. The scanning optical system satisfies the predetermined condition defined by lenses of Abbe number.

Abstract: A camera capable of taking pictures selectively in a standard or full size frame and a panorama frame having a reduced vertical dimension. This camera includes vertically movable light-shielding members for partly light-shielding an exposure range of the standard frame to set an exposure range of the panorama frame. When the panorama frame is selected, a warning is given on a display provided on the camera body to the effect that a date and other photographic information cannot be recorded on pictures taken in the panorama frame. The shutter of the camera includes an electronic device for detecting an amount of light traveling from a photographic object to which light is flashed. Output of this device is used for suitably controlling exposure for photography in the standard and panorama frames.

Abstract: A scanning optical system has, from the object side, an object-side lens unit, a mirror, and an image-side lens unit, and scans a object by rotating the mirror while forming an image of the object on a one-dimensional line sensor. Either the object-side lens unit or the image-side lens unit includes at least one aspherical surface that fulfills a defined condition in a range that fulfills a defined condition.

Abstract: A designing method of a zoom optical system wherein each zoom unit is formed of one optical element has steps of: selecting a spherical system, a gradient index system or a diffractive optical system and at least one more system as systems constituting the degree of design freedom of each zoom unit, optimizing each zoom unit with respect to third-order aberrations and chromatic aberration; and using an optical solution obtained by said optimizing step as the design start data.

Abstract: A gradient index lens has a base lens and a resin layer. The resin layer is formed on a surface of the base lens. The resin layer has an aspherical surface. The base lens has a gradient index.

Abstract: The object of the present invention is to provide a high-performance zoom lens system that having a small number of lens elements and can also be used for wide-angle purpose. In order to achieve the object, said zoom lens system has, from the object side, a first lens unit having positive refractive power and a second lens unit having negative refractive power, wherein said zoom lens system varies magnification by changing a distance between at least said first and second lens unit, wherein at least one of said lens units includes a gradient index lens, said gradient index lens having at least one aspherical surface.

Abstract: A zoom lens system includes two lens components, and zooming is performed by moving a first lens component. The zooming is performed along a zoom curve such that the first lens component is moved out so that in-focus condition is obtained at a subject distance predetermined with respect to each focal length. As the subject distance, an excess focal length or a subject distance where the far side of the depth of field is the maximum flash reachable distance or a subject distance where the near side of the depth of field is the shortest object distance or a subject distance where the object distance or the magnification is fixed is set according to the purpose.

Abstract: A zoom lens system has a plurality of lens units. Zooming is performed by varying distances between the lens units. A gradient index lens is included in the lens units. The gradient index lens has a gradient index in a direction vertical to an optical axis. The gradient index lens has at least one aspherical surface.

Abstract: The object of the present invention is to provide a high-performance zoom lens system that has a small number of lens elements and can also be used for wide-angle purpose. In order to achieve the object, said zoom lens system has, 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, wherein said zoom lens system varies magnification by changing a distance between at least said first and second lens units, wherein at least one of said lens units includes a gradient index lens, said gradient index lens having at least one aspherical surface.

Abstract: A zoom lens system includes a plurality of lens units. First to third focal length zones are set according to the focal length. During focusing, in the first focal length zone, the lens units are moved at a first constant ratio, and in the third focal length zone, the lens units are moved at a second constant ratio which is different from the first constant ratio. In the second focal length zone, the movement ratio of the lens units varies according to the focal length.

Abstract: A camera capable of taking pictures selectively in a standard or full size frame and a panorama frame having a reduced vertical dimension. This camera includes vertically movable light-shielding members for partly light-shielding an exposure range of the standard frame to set an exposure range of the panorama frame. When the panorama frame is selected, a warning is given on a display provided on the camera body to the effect that a date and other photographic information cannot be recorded on pictures taken in the panorama frame. The shutter of the camera includes an electronic device for detecting an amount of light traveling from a photographic object to which light is flashed. Output of this device is used for suitably controlling exposure for photography in the standard and panorama frames.

Abstract: An apparatus for driving a collapsible lens mount having several telescoping segments includes, for each movable segment, a transducer that expands and contracts responsive to a wave pulse and a drive shaft coupled to the transducer. By varying the wave pulse conditions, the expansion and contraction are made to occur at different rates. A coupling member on each segment frictionally engages the drive shaft and transmits movement of the drive shaft during relatively slow drive shaft movements to the lens segment. The apparatus may also include a lens hood driven by the transducer and drive shaft apparatus of the invention.

Abstract: A compact zoom lens system comprises, from the object side, a first lens component of a positive refractive power, a second lens component of a positive refractive power, and a third lens component of a negative refractive power. The first lens component has at least one aspherical surface. There are variable air spaces between the first and second lens components and between the second and third lens components.

Abstract: A single focal length lens system has a first negative lens element and a last negative lens element. The first negative lens element is disposed at an object side end of the lens system and the object side surface thereof is concave. The last negative lens element is disposed at an image side end of the lens system. The lens system fulfills the following condition: ##EQU1## wherein .phi.f represents the refractive power of the first negative lens element; and .phi.1 represents the refractive power of the last negative lens element.

Abstract: A new compact-size, light-weight and low-cost zoom lens system having a high optical quality with a very simple structure including, from the object side to the image side, a front lens group having a positive refractive power and a rear lens group having a negative refractive power. The zoom lens system is operated by changing the axial air distance between the front and rear lens groups during a zooming operation. The zoom lens system uses aspherical surfaces whose low-cost manufacturing has been enabled by the recent progresses in plastic molding technology and glass molding technology. Many embodiments of the lens compositions according to the present invention, and further more specific examples of the embodiments are described with figures and data that show compactness and high optical performance.