Abstract: The present invention is characterized in that when a phototaking lens system forms image information on a image pickup device in which a plurality of light-receiving elements are arranged in a non-square lattice pattern and a signal from the image pickup device is sampled in a square lattice to obtain a two-dimensional digital image, the phototaking lens system forms an image as optically correcting for a distortion of aspect ratio of image caused upon sampling in the square lattice.

Abstract: This invention velates to an image displaying apparatus which includes a plurality of image displaying devices for displaying respective display images on display surfaces thereof, reflecting surfaces provided in correspondence to the respective image display devices, each for reflecting a light beam from the corresponding image display device and an optical system for guiding light beams from the plurality of reflecting surfaces to a pupil of an observer.

Abstract: There is disclosed an image taking apparatus comprising a first optical unit for forming an image, a second optical unit positioned on the optical axis of the first optical unit, a third optical unit positioned behind the second optical unit and having plural lens units for re-focusing parts of the image of the first optical unit, converters for converting the plural images, formed by the third optical unit, into electrical signals, and a processor for processing the electrical signals from the converters in order to obtain an image of a high definition.

Abstract: A zoom lens device including a total of five lens units which are in order of lens units from the lens unit closest to an object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, a fourth lens unit having a positive refractive power, and a fifth lens unit having a positive refractive power. During magnification changes, the first, second, and fourth lens units move along the optical axis, while the third and fifth lens units are stationary. The zoom lens device satisfies the following conditions: (1) 0.7<f.sub.2 /f.sub.T <1.2; (2) 2.2<.vertline.f.sub.3 .vertline./f.sub.W <3.5; (3) 0.6<.vertline.f.sub.3 .vertline./f.sub.4 <1.45; and (4) f.sub.T <f.sub.4 <f.sub.5, where fi represents the focal length of the ith lens unit, and f.sub.T and f.sub.W represent the focal lengths at the telephoto end and the wide angle end, respectively.

Abstract: An image taking apparatus comprising a first optical unit for forming an image, a second optical unit positioned in the vicinity of the image, plural lens units for reforming the image, plural converters positioned at the positions of the reformed optical images and adapted to convert the optical images into electrical signals, and a processor for processing the electrical signals for obtaining an image of high definition.

Abstract: An image display apparatus comprises an image display device for emitting a light beam to display an image, and an observation optical system for guiding the light beam from the image display device to the pupil of an observer. The observation optical system has at least a concave, reflective surface and a convex, reflective surface in order from the pupil side of the observer along an optical axis of the light beam directed from the image display device to the pupil. The concave, reflective surface is located near the pupil.

Abstract: An image forming apparatus of this invention relates to an image forming apparatus for forming a color image and, more particularly, to a projector using the image forming apparatus. The image forming apparatus includes a color light illuminating system having first and second light sources for emitting different color light components, and first, second, and third imaging units or liquid crystal light valves for modulating the color light components to form color images. The first light source is a light source for mainly emitting two color components corresponding to the images formed by the first and second imaging units, and the second light source is a color light source for mainly emitting a color component corresponding to the image formed by the third imaging unit.

Abstract: A zoom lens is disclosed comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power and a fourth lens unit of positive refractive power, zooming from a wide-angle end to a telephoto end being performed by moving at least the first, second and fourth lens units in such a way that an air separation between the first and second lens units decreases, an air separation between the second and third lens units increases and an air separation between the third and fourth lens units decreases, wherein the form and the construction and arrangement of the members of the lens units and, if an aspheric surface is in use, its shape, are appropriately determined.

Abstract: A zoom lens of four-unit construction which comprises, in succession from the object side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power. During the zooming from the short focus side to the long focus side, the first lens unit and the fourth lens unit are moved toward the object side, the second lens unit is moved so that the air gap thereof with respect to the first lens unit may monotonously increase, and the third lens unit is moved so that the air gap thereof with respect to the second lens unit may monotonously decrease.

Abstract: A zoom lens having five groups. A first lens group has a positive refractive power; a second lens group has a negative refractive power; a third lens group has a positive refractive power; a fourth lens group has a negative refractive power; and a fifth lens group has a positive refractive power. The first through fifth lens groups are arranged in this order from the object side. A varifocal zooming operation is performed by changing a distance interval between respective lens groups and the second lens group is moved to perform a focusing operation.

Abstract: An ultra-wide-angle type zoom lens is disclosed, comprising, in the order from the object side, a negative first lens unit, a negative second lens unit and a positive third lens unit, wherein zooming from the wide-angle end to the telephoto end is performed by differentially moving the second and third lens units.

Abstract: A zoom lens is disclosed, comprising, from front to rear, first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power, a fourth lens unit of positive refractive power and a fifth lens unit of positive refractive power, the second and fourth lens units moving forward to vary the focal length from the wide-angle end to the telephoto end, and the first lens unit moving in a locus convex toward the image side to compensate for the image shift with zooming, wherein the following conditions are satisfied:f2<.vertline.f3.vertline.f5<5.multidot.fTwhere fi is the focal length of the i-th lens unit and fT is the longest focal length of the entire lens system.

Abstract: A zoom lens includes, in succession from the greatly conjugate side to the little conjugate side, a first lens unit having negative refractive power, and a second lens unit having positive refractive power. Zooming from the wide angle side to the telephoto side is effected by at least the second lens unit being moved toward the greatly conjugate side. The zoom lens satisfies the following condition:bf.sub.w /f.sub.w >1.6,where f.sub.w is the focal length of the entire system at the wide angle end, and bf.sub.w is the distance from the last lens surface of the second lens unit to the little conjugate side.

Abstract: A projection display apparatus, which projects a magnified image onto a screen, comprises an image forming system, such as a display panel, a projector including a plurality of lenses for projecting the image onto the screen, and a decentering mechanism for decentering some lenses in the projector with respect to the optical axis. Even if the image is distorted by arrangement of the screen and the optical axis and so on, the distortion is compensated by decentering the lenses and producing a decentering distortion.

Abstract: An internally focusing zoom lens with an optical axis and a first lens group having a positive refractive power. The first lens group consists of a front lens sub-group that has a positive refractive power and a rear lens sub-group that has a negative refractive power and is disposed on an image plane side of the front lens sub-group. The rear lens sub-group consists of a positive lens with one convex surface located on the image plane side thereof and a negative lens with two concave surfaces. The rear lens sub-group is moved along the optical axis of the zoom lens for focusing the zoom lens. The zoom lens also includes a second lens group having a negative refractive power which is moved along the optical axis of the zoom lens for zooming, a third lens group which is moved along the optical axis for zooming, and a fourth lens group having a positive refractive power.

Abstract: An automatic focusing device for performing focus detection through an objective optical system, and adjusting the focusing position of the objective optical system in accordance with the detection result, wherein the attachment or detachment of an optical element for changing the focal length of the objective optical system is detected, and the speed of the drive source is changed depending on the detection result.

Abstract: An interchangeable lens for a camera having a focus detecting device includes a memory having a plurality of memory areas. Each of the memory areas stores different correction values for correcting the focus condition of the lens for aberrations. Setting apparatus is coupled to the memory and allows the correction values from one of the memory areas to be enabled in order to carry out correction of the lens focus.

Abstract: A camera system has an interchangeable lens releasably attached to a camera body, an information processing portion provided in the camera body, and another information processing portion provided in the interchangeable lens. The information processing portion of the interchangeable lens discriminates the attachment of photographic supplementary means and communicates with the information processing portion in the camera body to set a photographic condition.

Abstract: A zoom lens including, from front to rear, a first lens unit of positive power, a second lens unit of negative power and a third lens unit of positive power, wherein for a standard focal length range at least the first and second lens units move simultaneously and independently of each other, and to obtain a focal length beyond the standard range, at least the second lens unit moves, whereby the locus of movement of the first lens unit bends at an end of the standard range, and as the standard range is exceeded, the first lens unit either remains stationary or moves forward.

Abstract: In a focusing method for the rear focus type of zoom lens where the range in which the focusing lens should be present for focusing to different object distances varies with zooming, the focusing lens is prevented from moving to the outside of the aforesaid range as zooming is performed. For this purpose, either the range of movement of the focusing lens is limited by a zooming lens arranged in front or in rear of the focusing lens, or the focusing lens is allowed to stand still regardless of zooming when focusing is effected on an object at a shortest distance.