Showing papers on "Real image published in 1971"

Optical system to reduce image to lens distance by polarization control

Abstract: Apparatus to reduce the real image to lens distance in an infinity image display system. By folding the optical path using an arrangement of beamsplitters and polarizers, the image to lens distance may be reduced by almost two thirds.

Electro-optical image composite display

Abstract: Electro-optical display system for providing a composite display of an optical image wherein a first image provided by means of a cathode ray display device is superpositioned onto a second image derived from hard copy information such as slides, maps or other character information. The system is comprised of a cathode ray tube with suitable means for directing a first light image generated by the cathode ray tube onto the photocathode of an image intensifier. The second image which may be projected by means of a slide projector is also focused onto the photocathode of the image intensifier. These two images directed onto the photocathode generate an electron image corresponding to the composite image of the first and second image. This electron image is then accelerated and amplified through the image intensifier to provide a visible light display by means of a suitable phosphor positioned at the opposite end of the image intensifier with respect to the photocathode. This output visible image is a composite image of the first two images.

Weather time display

Abstract: A weather-time display, such as for use in a closed-circuit of cable television system, includes a plurality of sensors for producing signals proportional to a corresponding plurality of selected environmental parameters. Those signals are sequentially applied to a meter to which a rotatable mirror is coupled. An image of an indicator is projected onto that mirror and from there it is reflected onto an image plane located at the viewing plane of a video camera. Images of scales calibrated in units appropriate to the sensed parameters are sequentially superimposed with the image of the indicator at the image plane such that sequential composite images of the scales and the indicator are formed for viewing and transmission by the video camera. If desired, and as herein shown, an image of the time may also be superimposed on the composite scale-indicator image at the image plane.

Reflex camera and viewer with a folded optical path

Abstract: A reflex camera and viewer with a folded optical path are described. The optical arrangement of the viewer permits an observer to see and thereby focus an image formed by the objective lens on a focusing screen within the camera. Folding the optical path of the viewer with a mirror near the objective lens permits locating the optic axis of the viewer almost normal to the focusing screen. Other optical elements situate in the optical path of the viewer include a lens forming a real image of the scene focused on the screen by the objective lens and an eye lens magnifying that real image to a convenient size for the observer. Orienting the axes of the two lenses in the viewer at a slight angle to the optic axis of the viewer reduces any field tilt and distortion in the image as seen through the viewer.

Diffraction-Limited Holography

Abstract: Experimental determinations of the size of the Airy disk for real image reconstructions of holograms of limited extent have yielded values comparable with those given by diffraction limitation. The holograms used are transmission, side-band holograms of low carrier frequency and are constructed in the far field of the object (~3-μm extent). In reconstruction, the real image is focused, with unit magnification, onto a rotating ground-glass plate and viewed through a microscope with 400× magnification. Comparisons of the reconstructed image with the actual object are made for holographic speeds ranging from f/10 to f/2 using visual, photographic, and photoelectric recordings. Photographic resolution tests, using standard bar patterns, yield a value of 1.05 for the ratio of the observed radius of the Airy disk to that corresponding to diffraction limitation. These tests are in disagreement with photoelectric measurements, the discrepancy being quantitatively ascribable to contrast enhancement in the film.

Illumination optical system for projecting multi-photographic image

Abstract: An illumination optical system for projecting multi-photographic images wherein the illumination light loss is minimized is provided by disposing a group of micro-lenses substantially similar to that used in the photographing optical system in the of and backwardly of an image plane; or displacing an illumination light source relative to said image plane in plane symmetrical relation with a movable photographing aperture; or disposing a light diffusion plate between said image plane and said micro-lens group; or disposing photographing and projection condenser lenses in symmetrical relation with respect to said image plane; or disposing the light source and the aperture in point symmetrical relation with respect to the center of said image plane; or positioning the light source relatively closer to said image plane; or focusing the optical image of the light source forwardly of the image plane after the light beams have passed through the image plane.

Calculation of the Optical Effects of a 27.5-m Spherical Mirror.

Abstract: People standing under a large spherical mirror see the world inverted, hanging above them as a real image. The shape of this image world depends upon where on the floor the observer stands. In this paper formulas for calculating image positions as a function of observer position are derived and depicted in diagrams of typical image worlds. The images formed by light reflecting several times in the mirror are also calculated. There are both an erect real image world and doubled rings of inverted images surrounding the single-reflection image world.