Showing papers on "Real image published in 1975"

Speckle minimization in projection displays by reducing spatial coherence of the image light

Abstract: An optical system for minimizing the speckle observed in a projected image, the image being produced by a projection display device. Coherent or non-coherent light illuminates the projection display device image and an image thereof is formed at an intermediate image plane. A narrow angle diffuser is positioned at the intermediate image plane and produces an enlarged illuminating aperture at the Fourier transform plane. The relatively large angle subtended by the illuminating aperture at a second image plane reduces the spatial coherence of the image formed thereat.

Image enhancement method and apparatus

Abstract: Combined optical and electronic apparatus provide for various types of image enhancement by producing two images of the same scene which differ by a predetermined property, and by electronically subtracting the images to yield a video difference signal which emphasizes or deemphasizes a predetermined characteristic of the scene at which the apparatus is pointed. Various types of image enhancement are obtained by simultaneous scanning of the images produced by two imaging systems in which a relative difference in properties between the images such as deliberate misalignment, optical density difference, image resolution, image magnification or image receptor displacement is introduced to create a particular type of enhancement. The intensities from pairs of scanned spots are subtracted on a point-by-point basis to yield a video difference signal which when displayed provides an image enhanced in a particular manner. Property differences are in general introduced in the aperture plane, at the optics or in the image plane. The subject system can be arranged for edge enhancement, size discrimination, emphasis of lines in a predetermined direction, peripheral image enhancement, and central image or boresite enhancement. This system is particularly useful in clutter rejection for TV-based target tracking systems.

Optical-electronic microscopy apparatus and process

Abstract: An apparatus and process for microscopy produces two real images of a specimen using light-optical means. The images have different light qualities and are then amplified electronically and rendered visible as a single image following a difference image method.

Compact microform reader

Abstract: A portable microform reader is provided with a microform carrier and a projection system for projecting an enlarged real image of the information carried on a portion of the microform onto a viewing screen. A binocular magnifying system is arranged for viewing the screen and for further enlarging the image thereon to produce a virtual image of acceptable reading size. The projection system comprises a source of illumination, a condenser lens, and a projection lens for projecting an image of the information carried on the microform onto the screen. The magnifying system may consist of appropriate binocular lenses where such lenses, in combination with prismatic converging means, produce the desired magnification. Beam splitting means may alternately be provided to eliminate the need for prismatic converging means, and a mirror arrangement may be provided to "fold" the projected beams for further limiting the size of the reader.

Optical system having a rotating screen

Abstract: An optical system in which a light image of an original document is projected onto a light sensitive member. The light image passes through a rotating screen at discrete time intervals forming successive half-tone light images at differing screen angles.

Corpuscular beam microscope, particularly electron microscope, with adjusting means for changing the position of the object to be imaged or the image of the object

Abstract: The determination and correction of the image drift in an electron microse is accomplished using a correction signal obtained by forming the convolution product of an actual object image (instantaneous microscope image) and a reference object image (microscope image at an earlier point in time) whose change in position is proportional to the image drift. The convolution product preferably is formed using an optical analog computer. To correct the image drift, the correlation signal is used as the controlled variable which acts on the image adjusting means.

Optical scanning systems with image curvature correcting means

Abstract: In an optical scanning system having a rotary scanner with multiple reflectors, which scanner images a light-responsive detector and moves that image repeatedly across the flat image field of an objective to generate a scanning raster, an optical corrector is mounted in the beam imaging the detector to correct for the fact that the detector image moves in a curved path. The optical corrector has a stepped surface such as to adjust the detector image incrementally during a scan, in the direction normal to the plane of the image field of the objective, so as to make the detector image motion substantially parallel to said image field.

Geometric model for holography

Abstract: A geometric model is developed to interpret the physical meaning of various major characteristics of ’’real’’ holograms. Without invoking highly mathematical principles, but, at the same time, without sacrificing basic physics, the model allows the development of an intuitive understanding of the following characteristics: the virtual image, the real image, redundancy, multiple scenes, white light or Lippmann–Bragg reflection holograms; and then leads into the explanation of the hypothetical ’’thin’’ hologram.

Automatic electronic rangefinder

Abstract: An automatic focusing system is provided to process amplitude and phase signals of image motion in an image plane. The camera includes a focusable objective lens, optical means, oscillating means, sensing means, and a servo. Light rays reflected from an object to be focused upon are received and refracted by the objective lens to the optical means which has a rear nodal point. The optical means receives and refracts the light rays to form an image of the object in an image plane. The optical means is oscillated about the rear nodal point by the oscillating means. While the optical means is being oscillated the image remains stationary in the image plane when the objective lens is focused upon the object, but is transversely displaced and oscillates in the image plane when the objective lens is not focused upon the object. The sensing means detects and processes amplitude and phase signals generated by image motion in the image plane and directs the servo to drive the objective lens into focus.

X:ray photograph to reform spatial image - utilises X:rays from several sources which pass through same raster to create 3-dimensional image

Abstract: The object (19) is irradiated from several X-ray sources at once (16), and the transmitted beams pass through a raster of holes or slots (20); the sources are so positioned with respect to the raster, that the several beams passing through the holes do not overlap at the photographic surface (21), though they preferably cover it completely. A second raster screen (22), chosen not to intercept any rays that contribute to the photographic image, may be placed in front of the object. A three-dimensional image of the object may be reconstructed from the shadow-graph and raster by illumination from behind, using a lens to focus light on the points (16) where the X-ray sources were. Thus the rays that formed the photographic image are re-constructed, at their shadow-graph intensities, and may be intercepted and displayed, section by section, on a screen held where the object was. Alternatively, a computer can be used to calculate sections from the known geometry.

Compressed optical system

Abstract: An optical system, particularly for use in an electrostatic copier of the type in which a document is scanned as it moves through an object plane, and an image transmitted to a photoconductive element which is moving through an image plane. A plurality of optical systems each including a lens of short focal length and a roof mirror, are adapted to transmit a portion of an illuminated object plane along parallel light paths. The images thus transmitted are so oriented with respect to each other as to form an integrated image on a receiving surface located at an image plane. In one embodiment the receiving surface is in the nature of a transfer mechanism which has the image cast thereupon in wrong reading orientation, and which mechanically transfers the image, in right reading orientation, to a copy sheet. By introducing an additional plane mirror into the system, the image can be converted to a right reading image for projection directly on a moving copy sheet at an image plane.

Projection system for display of parallax and perspective

Abstract: A projection system for the display of parallax and perspective of a real image from a hologram in which a reference beam is projected in a sequence of several projections at selected angles of perspective through the hologram, this sequence being rapidly performed. The resulting angular spaced images emitting from the hologram are directed onto a mirror which is coordinately tilted to reflect all of the resulting images in register onto a screen where they appear as a single three-dimensional image.

Projection of objects emitting gamma rays - which form visible images with X-ray video amplifier tube having gamma-ray sensitive screen

Abstract: A conventional apertured-disc matrix inserted as a screening mask in the gamma-ray path, is used to project on the gamma-ray screen of the gamma-ray video amplifier tube, in the manner of a camera obscura, a number, corresponding to the number of holes in the disc, of equal individual images representing a part of the object. This is done in such a way that electrons released on the large-area photoelectric cathode on the back of the screen are projected onto another screen to form a common visible image or, instead, converted on a storage electrode into a charge image for further image storage amplification.

Measurement of distance from object to reference system - involves optical image correlator with at least one correlation structure

Abstract: A real image moves relatively to the image correlator. A structure is projected on the object within the field of vision of the correlator, whose azimuthal orientation is rigidly coupled with that of the correlation structure. Amplitude and fundamental wave of the photoelectric signals generated by the interaction of light fluxes are reflected from the object with the correlator, and are evaluated in order to obtain the distance to the object. A projector connected to the image correlator projects an image of the structure onto the tested object; this structure changes its shape only in accordance with a given spatial direction, and its shape and orientation correspond to the correlation structures.

Holographic Technique for Measuring Surfaces

Abstract: A holographic method for surface mapping is described, and the results obtained, with respect to accuracy and data retrieval rate, are compared to those obtained by stereophotograrnmetry. With the holographic technique, in which a real image of the surface is scanned automatically, greater accuracy is achieved and data are retrieved more rapidly. A high-power pulsed laser technique is also described which allows extending the method to non-stationary objects. Although developed primarily for automotive model mapping, the method is applicable to other areas such as anthropometry.