Abstract: A zoom lens system includes a negative first lens group, an aperture stop, and a positive second lens group, arranged in this order from an object side. The first and second lens groups are movable along an optical axis for zooming, while the aperture stop, which is disposed between the lens groups, stays unmoved during zooming. The zoom lens system satisfies conditions (1), (2) and (3): 0.7<(fi−fw)/(ft−fw)<1.0   (1); and 0.37<di/fw   (2) 0.3<fw/f2<0.7   (3) where fi is a focal length of the entire system when the total length of the entire system becomes shortest, fw is the shortest focal length of the entire system, ft is the longest focal length of the entire system, di is air gap between the first lens group and the aperture stop when the total length is the shortest and f2 is a focal length of the second lens group.

Abstract: A telephoto zoom lens includes a first positive lens group, a second negative lens group, a third positive lens group and a fourth lens group. A resultant refractive power of the third and fourth lens groups are moved from an image side to an object side upon zooming from a short focal length extremity to a long focal length extremity, so that a distance between the first and second lens groups increases, a distance between the second and third lens groups decreases, and a distance between the third and fourth lens groups becomes smallest at an intermediate focal length. The zoom lens satisfies a condition specified by (0.1<X.sub.3 /X.sub.1 <0.5), wherein X.sub.1 represents a distance between a position at the short focal length extremity and at the long focal length extremity of the first lens group on an optical axis, and X.sub.

Abstract: A photographic lens system composed of a negative first lens group, a diaphragm, and a positive second lens group, in this order from the object side. The second lens group has a positive meniscus lens element having a convex surface facing the image side, a cemented sub-lens group having a positive lens element and a negative lens element, and a positive single lens element, in this order from the object side, wherein the photographic lens system satisfies the following conditions:1.5<.vertline.f.sub.1 .vertline./f<5.0 (1)1.1<f.sub.2 /f<2.0 (2)0.6<D.sub.AS /f.sub.2 <1.2 (3)whereinf designates the focal length of the entire optical system;f.sub.1 designates the focal length of the first lens group;f.sub.2 designates the focal length of the second lens group;D.sub.AS designates the distance from the diaphragm to the first principal point of the second lens group.

Abstract: A data printing device is provided which comprises a light emitting device that includes a plurality of light emitting elements, and an imaging optical system for forming light spots corresponding to the light emitting elements on the film. Preferably, the imaging optical system satisfies the following condition: 0.6<.vertline.m.vertline.<1.5, where "m" represents the magnification of the imaging optical system. The light emitting device comprises a light emitting diode in which a plurality of light emitting elements are included on a single substrate. The plurality of light emitting elements are aligned along a straight line perpendicular to a direction of film winding. The imaging optical system includes of a single imaging lens or a plurality of lenses.

Abstract: A zoom lens system includes a positive first lens group, a negative second lens group, and a positive third lens group. The second and third lens groups move to perform a zooming operation. The zoom lens system satisfies the relationships 0<logZ.sub.2 /logZ<0.4; 0.25<d.sub.1-2 /f.sub.W <0.55; and 3<L.sub.2-3 /f.sub.W <4.6, wherein "Z.sub.2 " designates the ratio defined by the lateral magnification of the second lens group at the longest focal length extremity to the lateral magnification of the second lens group at the shortest focal length extremity, "Z" represents the ratio defined by the longest focal length of the entire zoom lens system to the shortest focal length of the entire zoom lens system, "f.sub.W " represents the shortest focal length of the entire zoom lens system, "d.sub.1-2 " represents the distance between the last lens surface of the first lens group and the first lens surface of the second lens group at the shortest focal length extremity, and "L.sub.

Abstract: A zoom lens includes a first movable lens group having negative power and a second movable lens group having positive power, and an immovable diaphragm provided between the first and second lens groups so as not to move during the zooming operation. The zoom lens satisfies (1) 0.45<f.sub.w /f.sub.2 <0.7, (2) 0.5<f.sub.2 /.vertline.f.sub.1 .vertline.<1.0, and (3) 0.8<D.sub.w /f.sub.2 <1.3, whereby f.sub.w represents the focal length of the entire optical system at the wide-angle extremity, f.sub.1 represents the focal length of the first lens group (f.sub.1 <0), f.sub.2 represents the focal length of the second lens group (f.sub.2 >0), and D.sub.w represents the distance between the diaphragm and the first principal point of the second lens group at the wide-angle extremity.

Abstract: There are arranged, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power, the first and fourth lens groups being fixed whereas the second and third lens groups are moved in the axial direction to effect zooming. Further, the following conditions (1), (2) and (3) are satisfied:(1) 1.2<H.sub.4MAX /H.sub.4-l <1.6(2) 0.3<f.sub.T /f.sub.1 <1.0(3) 0.35<.vertline.f.sub.w /f.sub.2 .vertline.<0.70where H.sub.4MAX is the maximum height of the axial ray through the fourth lens group, H.sub.4-l is the height of the axial ray intercept at lens element 4-l in the fourth lens group which is located closest to the object side, f.sub.T is the focal length of the overall system at the telephoto end, f.sub.W is the focal length of the overall system at the wide-angle end, f.sub.

Abstract: A data printing device comprises a light emitting device that includes a plurality of light emitting elements, and an imaging optical system for forming light points on the film which correspond to the light emitting elements. The imaging optical system includes at least one imaging lens and at least three reflecting surfaces that reflect the light from the light emitting device to bend the optical path along an arc of a cylindrical wall of a film space, such as a spool chamber or a cartridge chamber.

Abstract: An anamorphic lens system in an eye direction detection device, applied to an observing optical system, modifies illumination light from a light source to be parallel in a lateral direction of a user's eye positioned to look through the observing optical system, dispersed in a vertical direction of the position of the user's eye, and substantially centered on the position of the user's eye. The anamorphic lens system transmits the illumination light from the light source to an illumination light exit surface positioned away from the optical axis of the observing optical system, and the illumination light is projected toward the position of the user's eye from the illumination light exit surface to separate signals from the image of the eye and an image formed by eyeglasses, if worn. The illumination light exit surface is a rectangular window having a longitudinal side parallel to longitudinal side of a field of view of the observing optical system, and is positioned below the position of a user's eye.

Abstract: An indicating apparatus within a finder of a single lens reflex camera includes a mirror which reflects light of an object transmitted through a photographing lens to form an object image on a focusing plate, and a finder optical system through which an image of the object formed on the focusing plate is viewed. The indicating apparatus further includes a mirror box which supports the mirror, and a photographing information projector provided on the lower portion of the mirror box to project and indicate an image of the photographing information onto the focusing plate without interfering with the front end of the mirror.