Abstract: A focus detecting device arranged to detect the focusing condition of an objective lens by projecting a light flux from a light source onto an object through the objective lens and by sensing the light flux after it is reflected from the object. The focus detecting device is provided with sensors which produce information necessary for detecting the focal point of the objective lens by sensing the light of the light source reflected by the object. Degradation of the device's detection accuracy due to the eccentrically mounted objective lens is prevented when these sensors are symmetrically arranged relative to a plane containing the optical axis of the objective lens.

Abstract: A method and apparatus for detecting the focus state of an object image pattern in accordance with a plurality of photo-electrically converted output signals, including a first mode in which the plurality of photo-electrically converted output signals are sampled at different times and statistically processed for each output, wherein the focus state is detected in accordance with the statistically processed outputs, and a second mode for detecting the focus state without the statistical processing.

Abstract: A device for distinguishing focusing conditions of an objective lens by a plurality of optical apparatus for forming images based on respective light beams passing through different areas of a pupil of the objective lens and photo-electric transducing apparatus for sensing the degree of coincidence of the images formed by the optical apparatus. The aforesaid optical apparatus are in contact with each other increasing the amount of one of the light beams passing through the pupil of the aforesaid objective lens, which is conducted to the aforesaid optical apparatus, wherein the contacted portion of each optical apparatus is provided with light-shielding apparatus.

Abstract: A device for detecting the focused state of an objective lens comprises a re-imaging lens unit arranged to distribute light from a primary image formed by the objective lens to form secondary images which have their relative positions varying with the focused state of the objective lens, the re-imaging lens unit including a plurality of re-imaging lenses having a plurality of lens surfaces; and sensing means arranged to sense the light distributions made for the secondary images and to produce signals to be used in computing information on the focused state of the objective lens according to the relative positional relation between light distributions for the secondary images, the sensing means having a plurality of photosensors. In detecting the focused state of the objective lens, the optical axis of at least one of the lens surfaces of each of the re-imaging lenses is decentered relative to other lens surfaces in parallel with the direction in which the photosensors are arrayed.

Abstract: A focus detection system includes an object lens for focusing an image of an object, a refocusing optical system for refocusing a plurality of component image having parallax from the image of the image, a view field mask arranged between the object lens and the refocusing optical system and having a laterally extending aperture, and a sensing device having a photo-sensor array for sensing the component images. Focus detection error is prevented by determining a sense area of the photo-sensor array in accordance with a distortion created in an aperture image by the refocusing optical system.

Abstract: A system for detecting the focus of an imaging lens relative to an object includes re-imaging means disposed on the imaging side of the imaging lens and having pupil dividing means for dividing the pupil of the imaging lens into a plurality of areas, the re-imaging means forming a secondary object image of the object from a light beam passed through the plurality of divided areas, an optical system disposed near the predetermined imaging plane of the imaging lens and having a reflecting surface for directing a primary object image of the object to the re-imaging means, and light-receiving means on which the secondary object image by the re-imaging means is formed.

Abstract: This specification discloses a focus detecting system in which a plurality of images are formed on the basis of light beams passing through different portions of the pupil of an objective lens and the focus state of the objective lens is detected from the relative positional relation of these images and wherein filters of which the density distribution varies along the direction of arrangement of photoelectric conversion elements are disposed in front of photoelectric conversion element arrays for detecting the distributions of quantity of light of the images, thereby accomplishing shading correction.

Abstract: This is disclosed an exposure control device capable of controlling an exposure by using a CCD etc. sensor in which CCD sensor is also used for detecting a focus state of an imaging lens of camera or the like.

Abstract: A focus detection apparatus has a field lens on or in a vicinity of an anticipated focal plane of an imaging lens and a refocusing optical system arranged behind the field lens to focus light beams transmitted through different areas in a pupil of the imaging lens onto a photo-sensor array to form a secondary image thereon, and detects a focus in accordance with an output signal of the photo-sensor array. A filter which blocks an infrared ray and transmits a visible ray is arranged adjacent to the field lens to prevent degradation of a filtering characteristic which depends on an inclination of a main light impinging to the filter.

Abstract: In an apparatus wherein on the basis of a light passing through an objective lens, a plurality of images whose relative positional relation varies in accordance with the focus state of the objective lens are formed and these images are detected by photoelectric conversion element arrays and a predetermined operation is effected by the use of a plurality of photoelectrically converted signals obtained correspondingly to the respective images to thereby detect the focus state of the objective lens, there are provided first adder means for comparing the photoelectrically converted signals of the respective images in a predetermined relation and adding the smaller signal and second adder means for comparing the photoelectrically connected signals of the respective images in a predetermined relation and adding the greater signal and focus detection is effected by utilization of the result of the addition of one of the first and second adder means in accordance with the object condition, whereby accurate focus dete

Abstract: A diffusing plate having a smooth rough surface is obtained by recording on a photosensitive material the image of a mask having a regular fine pattern thereon, treating the photosensitive material to thereby obtain a photosensitive material having smooth roughness, transferring the smooth roughness of the treated photosensitive material to a metal mold, and embossing plastics on the metal mold.

Abstract: In an in-focus state detection device for a camera for forming a plurality of images based on light fluxes transmitted through different areas of a pupil of an imaging lens and detecting the state of the imaging lens based on a relative positional relationship of the images, an optical system for forming the images and a sensor for sensing the images are constructed in a unit through two opposing mirrors to allow ready mounting of the optical system and the sensor, and the positions of the optical system and the sensor are adjusted through the unit member.

Abstract: In a focus detecting apparatus for detecting a focusing state of an objective lens in such a manner that light is projected on an object and light reflected by the object is sensed through an objective lens, a lens is disposed between an imaging lens and an objective lens which are used to form an image in accordance with light reflected by the object. The lens between the imaging lens and the objective lens focuses an entrance pupil of the imaging for lens and an exit pupil of the objective lens, thereby effectively guiding the reflected light to a sensor. At the same time, the light-emitting element, the condenser lens, the sensor and the imaging lens are mounted around a penta prism through a plurality of reflectors, so that a camera can be made compact.

Abstract: In the disclosed camera, an optical arrangement projects substantially collimated light rays from a light emitter toward an object through an objective system in a finder, and a light receiver produces a signal that determines the relationship between the object and the camera by detecting the light from the objective system after reflection by the object.

Abstract: A focusing screen includes a plurality of light deflecting portions, each of which includes a prism component having a light deflecting function for providing part of an out-of-focus image with displacement in one direction, and a diffraction grating component formed on the prism component and having a plurality of unit structures. At least a portion of each of the unit structures is formed by a curved surface.

Abstract: This application relates to a diffusion plate having microlens-like curved surfaces of a size of 10 to several tens of .mu.m arranged periodically in two dimensions on the surface of the substrate thereof. Curved surfaces are formed between the microlens-like curved surfaces. Further, irregularly arranged minute concave and/or convex surfaces are formed on the microlens-like curved surfaces.

Abstract: A focussing plate for photographic cameras, etc. which is constructed with a multitude of micro-lens shaped curved surfaces arranged on a substrate surface at a space interval among them of from 5 to 30 .mu.m, and other curved surfaces arranged in the boundary spaces among these micro-lens shaped curved surfaces having a curvature just opposite to that of the micro-lens shaped curved surfaces.