Abstract: A color copier has a control circuit for controlling the exposure of an original to be copied. The control circuit has a processing channel for each of the three primary colors. Each of the channels is associated with photodetectors which is sensitive to the color of the respective channel. The photodetectors sense the intensity of the light in the respective color transmitted through the original and generate signals indicative of the density of the original in that color. The density of the original in each color is compared with the neutral gray density of the original. The difference between the density of each color and the neutral gray density is used to calculate an undercorrection factor for the respective color. The undercorrection factor is used to regulate the exposure time for light of the respective color or the intensity of light of the respective color during exposure.

Abstract: In the light path of a photographic enlarger, a supplementary light source is arranged in such a way that an image thereof is formed by the condenser in the focal plane of the imaging lens but outside the range covered by the latter. If the original to be printed has scratches, these deflect at least a part of the light, which reaches them from the supplementary light source into the lens. As a result, that proportion of the actual printing light supplied by the printing light source which is deflected past the lens by the scratches is at least partially compensated. The image of the scratches on the printing material is virtually invisible.

Abstract: An enlarger head for multigrade paper is described which comprises a light mixing system for mixing light from two sources.The system comprises disposed along a longitudinal axis a solid light-mixing member of an optically clear material which has as a light-input face a generally planar sulcated face having grooves therein of equilateral triangular cross-section and a substantially smooth light-output face, said two light sources being diametrically opposed relative to the longitudinal axis and each being adapted to direct light onto said light-mixing member from an angle substantially 60.degree.

Abstract: An illuminating system has as main components: a light source comprising four low voltage lamps and, associated therewith, reflectors and condenser lenses, a filter unit, an image-producing pair of lenses, a deflecting mirror and light-mixing element made of glass. The condenser lenses produce images of the coils of the low voltage lamps in the central horizontal plane of the filter unit. Images of the condenser lenses are produced by the image-producing lens pair in a light entry face of the light-mixing element. This light entry face is provided with ribbings constituting cylindrical lenses of special dimensioning which effect homogenization of the light in the light-mixing element. In order to reduce light losses, the light-mixing element is composed of two frusto pyramidal element parts and has its smallest cross-sectional area in a middle region in which the smaller end faces of the frusto pyramidal parts are joined to an interposed diffusor disc.

Abstract: Electronic imaging apparatus of the kind having an imaging zone; a light valve array comprising a plurality of discretely-addressable light-modulating pixel regions; illuminating means for directing light to the imaging zone via the array and means for addressing the pixels in accordance with image information, features light control means located between the illuminating means and such array for collimating illuminating light in a direction substantially normal to the ingress surface of the array.

Abstract: A color photographic imaging process and system uses a photographic film and/or printing paper wherein blue, green and red light is radiated on corresponding yellow, magenta and cyan dyes to obtain an image and the peak transmittances of the blue, green and red light are modulated to vary the resulting contrast of the color image.

Abstract: A slit-exposure type illumination apparatus capable of scanning a stationary original document by swinging an exposure lamp at a predetermined position and having side reflectors on the opposite sides of each linear light source and a pair of auxiliary plane reflectors which are disposed in the scanning direction of the illumination apparatus.

Abstract: An adapter and process for fitting an Omega C-700 color head to an Omega D type condenser enlarger. The adapter includes a circular plate member having a flange along its periphery, a generally rectangular aperture and a circular recess, and an L-shaped bracket.

Abstract: An apparatus for creating images of nonperiodic patterns, which patterns are variable in contrast with respect to a uniform and constant level of background luminance. Two beams of uniform luminance are projected through individual, orthogonally oriented linear polarizers, and then into a common cube beam splitter to be divided and interlaced. One combined output beam from the splitter is projected through a rotatable linear polarizer onto the image sensing optical detector undergoing test. The second beam is projected toward a detection system. The patterned region of the second beam passes through a second rotatable linear polarizer, synchronized to the first rotatable polarizer, and onto a CCD array detector system. Contrast between the pattern and the background is represented by the two electrical voltage levels in the array output, irrespective of the spatial frequencies in the pattern.

Abstract: An apparatus for generating patterned images which are variable in color contrast and spatial frequency while retaining a substantially constant, uniform level of photometric luminance. Two broad spectrum beams of luminous energy are individually projected through two orthogonally oriented polarizers and interleaved upon being split. The intensity in one beam is homogeneous while the other contains a spatially periodic pattern. The two beams created by splitting and interleaving are selectively color filtered and combined after one is translated sufficiently to reverse its phase relative to the other. A rotating polarizer in the path of the output combined beam alters the pattern color composition between one extreme where the spatially reversing colors are defined by the color filters and the opposite extreme in which the pattern disappears into a uniform composition of the two colors.

Abstract: The lamphouse is useful for the production of prints on variable contrast material or on conventional photographic material. A first tungsten filament lamp is provided from which light passes through a first color selective waveband filter. Another tungsten filament lamp is provided from which light passes through a second color selective waveband filter.In the lamphouse there is a removable rectangular light box. The top of the box is covered with a light diffusing and reflecting material. The bottom of the box comprises a rectangular light diffusing screen. The light box has on each of the sides adjacent to the two lamps a light entry port. In the lamphouse there are also two guide members which are parallel to the plane of the screen in the light box and on or in which the two lamps and their filters, guide mounting means and optionally lamphouse abutment means are slideably mounted.

Abstract: First and second fixed light sources each comprising a lamp and an elliptical reflector radiate light onto first and second plane mirrors which reflect the light onto an original document. A drive means rotates the first and second reflectors in an interlocked manner such that the reflected light therefrom scanningly sweeps across the document in superimposed relation. The axes of the elliptical reflector are arranged so that the edges of the document are illuminated with greater intensity than the center thereof.

Abstract: An additive tri-color lamp house having three lamps for conveying filtered light into a mixing chamber and illuminating a photographic image contained on a photographic film. The illuminated image is then projected onto a photosensitive paper for the purpose of making photographic prints and copies. The lamp house is characterized by having a combination of additive primary color filters and subtractive primary color filters positioned in front of the lamps and the amount of each additive primary color (i.e. red, green and blue) conveyed through the filters is controlled. By the proper positioning of the color filters in front of the lamps, the time required for proper exposure of the three separate emulsion layers on conventional color print paper is approximately equal.

Abstract: A light source including a plurality of different individual lamps providing primary colors. A mirror which selectively reflects is associated with each lamp. The mirror reflects the corresponding primary color through a filter into a color mixing chamber which provides light having predetermined color composition. A photocell sensing system senses the light in the mixing chamber to provide electrical signals corresponding to the intensity of each color. The signals are employed in a color composition control system for controlling the intensity of the individual light lamps.

Abstract: A method for additive mixing of colors wherein different colored light beams are mixed after being reflected from a rotating reflecting device. An apparatus for additive color mixing comprising sources of different colored light beams with devices for controlling their intensity, a mixing chamber and a device for cooling the system wherein, in the mixing chamber and opposite the light sources there is provided a rotating reflection device secured on a shaft which is rotatable and which reflection device has cooling vanes or fins formed on its periphery.

Abstract: An improved light source for a photographic printer uses a plurality of print lamps. A heatsink and blower dissipate heat generated by the print lamps. The light diffuser which diffuses light from the lamp includes a white porcelain diffuse reflector.

Abstract: A microform data acquisition processing and storage system in which data is fed from a computer, tape or cards to a cathode ray tube from whence an image produced on the tube is projected onto a photographic film or alternatively by means of an optical switching device an image of a document located on a document platen within the apparatus can be projected on to the same film without changing the film; the cathode ray tube is provided with a coating having a spectral peak between 500 and 600 nm so as to match the spectral peak of the image on the platen.

Abstract: A light source of adjustable colour is provided, primarily for use in apparatus for printing coloured originals. The invention is primarily useful in printing photographs.According to one aspect of the invention there is provided a light source of adjustable colour, comprising three light emitters of seperately adjustable intensity, a light mixer adapted to mix light emitted by the emitters into one beam, and filtering means whereby the first emitter emits light containing one additive primary colour, the second emitter emits light containing the same colour and one other additive primary colour, and the third emitter emits light of all three additive primary colours.The colour emitted by all the emitters, and therefore most easily adjustable to be richest in the final light beam, is, when the light is used for printing photographs, that colour which takes longest to develop.

Abstract: Multiple images of a common scene are formed by exposure of photographic film primarily to separated zones of the actinic electromagnetic spectrum. The several film images are illuminated individually with lights of selected chromaticities. The chromaticity of the light illuminating at least one of the images is widely separated from the chromaticity associated with the corresponding exposing spectral zone for that image. The illuminated images are displayed in registration for evaluation.