Showing papers on "Real image published in 1973"

Optical tracking system utilizing spaced-apart detector elements

Abstract: An optical tracking system in which an image of an object to be tracked is nutated about the image plane. Individual detector elements are arranged in a hexagonal array within the image plane such that each of the individual detector elements are located at respectively the centers of contiguous hexagonal cells. The nutation is provided, in one embodiment, by means of a tiltable mirror which rotates about an axis through the center of the mirror. The angle of tilt is variable so that the nutation can be varied to provide circular motion of an image point in circles concentric with a hexagonal cell and of varying diameter and, in particular, the image point can thereby be made to spiral inwardly toward the center of a hexagonal cell. The nutation of image points relative to the positions of the detector elements permit the various portions of an image to be scanned by individual detector elements. The inward spiraling of image points is utilized to provide for acquisition of the image points, and the position of an image point relative to a detector element at a given instant of time is utilized to provide elevation and azimuthal tracking data for tracking a desired object.

Non-contact type dimension measuring device

Abstract: Disclosed is a non-contact type dimension measuring device which comprises a light source for projecting collimated rays to an object to be measured, a convex lens for receiving the rays which are not screened by the object, to cause the rays to converge at its focal point, a first screen plate having a slit located at the focal point of the convex lens, a second screen plate having a large number of photoelectric converter elements arranged one one surface thereof on which surface an magnified image of the object is formed by the rays passing through the slit of the first screen plate, and an operational circuit responsive to electric signals from the photoelectric converter elements for determining the dimension of the object.

Distortionless recording in double-exposure holographic interferometry.

Abstract: When measuring two- or three-dimensional displacements by double-exposure holographic interferometry, observing directions of the same number are necessary to determine displacement vectors In the conventional method, identification of the corresponding points on the three interferograms requires a great effort since object images have different shapes for each observing direction To eliminate this laborious process, a method of distortionless recording, which utilizes the real image with the fringes formed on the original object surface shown by experiments

Holographic System for Automatic Surface Mapping

Abstract: The surfaces of large (approximately 1-m) diffusely reflecting objects can be mapped by automatic following of the holographic real image of the object. Large aperture, low f number holograms give the shallow depth of focus required for this method. The ability to apply the technique to situations requiring a pulsed laser is demonstrated. Unity magnification real images from holograms made with a Q-switched ruby laser have a measured metric fidelity of at least one part in 104 over an object field of 60 deg. A sinusoidal optical interference pattern projected onto the object when the hologram is taken provides the type of contrast pattern necessary for unambiguous determination of the location of the focused image surface and facilitates automatic focus detection. The image is scanned by an image dissector that is moved about the image by a 3-axis slide system. A computer analyzes the video signals, directs the machine motions to follow the image, and provides an output of surface dimensions in digital form. A prototype machine using cw helium–neon lasers for object illumination and image reconstruction is described and performance data presented.

Optical system for forming an image of an object in a given plane

Abstract: A system for forming an image of an object in an image plane is described By disposing a reflecting diaphragm in the back focal plane of an objective lens system, the curvature of this diaphragm being adjustable by means of a control element to which an electric signal supplied by an image detection system is applied, the size of the image in the image plane can be rendered independent of a change in the distances from the object to the optical system and from this system to the image plane

Half-tone image reproduction

Abstract: In image reproduction apparatus employing a scanning light spot to expose a light-sensitive sheet, a half-tone image is produced by moving a light-transmitting half-tone screen element through the light path between the light source and the light-sensitive sheet at a point in the light path conjugate with the light spot on the sheet. In this way an image of the moving screen element, which may be a rotating loop of film, is formed at the light-sensitive surface.

Parallax free viewer

Abstract: A novel viewing arrangement for a reflex camera includes a concave mirror that forms an image of a focusing screen through a window in a plane mirror that folds the reflex camera''s optical path. The concave mirror is conaxial with the center of an echelon mirror formed on the surface of, and concentric with, the focusing screen. It forms an aerial image of the focusing screen and the real image formed thereon by the camera''s objective lens. An eye lens magnifies the aerial image for a user who views the scene through it from an eye station. One embodiment utilizes an ellipsoidal reflecting surface on the concave mirror. Another embodiment utilizes a parabolic reflecting surface on the concave mirror and a plane mirror to erect the image and direct it toward the eye lens.

Method for providing a luminous multi-color image

Abstract: A luminous multi-color image such as a television picture or projected motion picture is provided by forming a luminous variative-intensity monochrome color image having bright, dark and intermediate areas and simultaneously uniformly superimposing on the monochrome image an illumination of a second visually distinguishable color. The intensity of the superimposed illumination is adjusted such that in the bright areas of the variative-intensity image, the monochrome color ''''washes out'''' the second visually distinguishable color. In the dark areas of the variative-intensity image, the second color predominates. The intermediate areas of the variative-intensity image appear as mixtures of the monochrome color and the second visually distinguishable color. The monochrome image may either be a self-luminous image formed on the face of a cathode ray tube or an image projected onto a viewing screen by a variety of techniques such as a slide projector, motion picture projector, etc. The second visually distinguishable color is uniformly superimposed on the monochrome image by either projecting it on a transparent viewing screen placed between the luminous image and the observer or by direct projection upon the same screen on which the luminous image is formed. By this method, a luminous multi-color image can be provided even though the signal forming the variative-intensity image contains no color information. For example, by proper selection of colors, a black-amd-white video image can be transformed into a multi-color image which is a first approximation of the true colors of the objects portrayed by the black-and-white picture.

Electronic optical transfer function analyzer

Abstract: An electronic optical analyzer for use in systems such as optical transfer function analyzers eliminates mechanical scanning systems and comprises entirely electronic image dissection means for dissecting an image transmitted by an optical system under test and producing an electric output signal representative of the beam intensity at a selected element of the image. The image dissection means is preferably (in the case of visible light) an image dissector tube whose positioning coils serve as an image element addressing means. The system is useable with any optical system including visible light, other electromagnetic radiation or charged particles (ions or electrons) so long as the image dissection means is responsive to the beam in question. The optical system under test must produce a real image at the image dissection surface of the image dissection means in order for readily evaluatable data to be obtained. The entire system is preferably computer controlled in order to obtain the necessary data quickly and accurately and to calculate the optical transfer function of the optical system under test on line. With this system both the modulation transfer function and the phase transfer function may be calculated. The digital computer can control the analyzer in any of several modes such as single scan, multiple scan with averaging of values to improve the signal to noise ratio and pass/fail production testing. output from the computer can be in any of several forms, such as displays on display devices, printouts or process control commands such as accept/reject commands in production testing.