Abstract: A wafer with a lacquer layer applied to it is checked automatically by lighting the wafer directly, so that the lacquer layer reflects the light. Resultant reflectance values of the reflected light are ascertained and buffer-stored and compared with corresponding values for a comparison wafer. It is ascertained whether the wafer is OK or defective from the result of the comparison in accordance with at least one predetermined judgment criterion.

Abstract: In a method for checking semiconductor wafers and apparatuses for carrying out the method, a lacquer layer applied on a semiconductor wafer is checked. Initially, regions which are to be excluded from the check and surfaces which are to be checked, are ascertained. The checking is effected by direct illumination in such a way that the lacquer layer reflects light. The resulting values of the reflectance are determined and buffer-stored. A determination is performed for each surface as to whether or not it is to be accepted or rejected, in accordance with a predetermined evaluation criterion.

Abstract: One embodiment of an apparatus for checking semiconductor wafers includes a receiver for a semiconductor wafer to be checked. A light illuminates the wafer. A hemispherical hood has a surface and a hemispherical region defining an interior inside the hemispherical region. A further hood is disposed in the vicinity of the light. A camera is disposed at the hemispherical hood and has a lens looking into the interior inside the hemispherical hood. A evaluator is connected to the camera for controlling the camera and receiving, buffer-storing, processing and outputing data transmitted by the camera. Another embodiment includes a first light directly illuminates the wafer with light of a first color and a second light indirectly illuminates the wafer with light of a second color being complementary to the first color. A surface of the hood is of the second color.

Abstract: A strip of originals is copied onto a band of copy material at high speed using a highly automated copier which measures the densities of the originals in the primary colors and calculates exposures from the densities. The calculated exposures for each original in each primary color are recorded. The band of exposed copy material is developed and the copies are evaluated. Unsatisfactory copies are marked. The band of copy material is subsequently cut into individual copies and the unsatisfactory copies, as well as the corresponding originals, are collected. These originals are recopied in a second copier which is far less sophisticated and expensive than the first copier. The exposures used to recopy an original are derived by applying correction factors to the recorded exposures for the original. By performing the recopying procedures, which are rather slow because they require manual operations, in a second copier, the output of the high speed copier can be maintained.

Abstract: A photographic copier has a first platform for supporting an original to be copied, and a second platform for supporting copy paper. A focusing system is disposed between the platforms and includes a plate which can be mounted at different distances from the platforms. The plate has a central opening which removably receives a tubular holder. The holder is supported in the opening by a ring which permits the position of the holder relative to the plate to be adjusted. Two lenses are removably mounted in the holder and serve to project an image of the original onto the copy paper. Different magnifications can be achieved in that the copier comes equipped with a variety of holders having different lengths, and a few selected lenses having different optical characteristics. The magnification is changed by simply interchanging holders and/or lenses, and adjusting the position of a holder to be used relative to the plate.

Abstract: A photographic copying machine wherein each of the three color filters comprises several triangular sectors which are pivotable about parallel axes into and from the path of copying light between first positions outside of the path, second positions of full overlap with the path and a finite or infinite number of intermediate positions. The pulleys for the sectors of each filter are rotatable by a discrete endless cord or cable which is further trained over a wheel receiving torque from a crank drive designed to move the sectors into the path of the light beam through progressively greater angles during movement from the second toward the first positions and through progressively smaller angles during movement from the first to the second positions under the action of a reversible stepping motor so that the crank drive can compensate for the lack of linearity between the filtering action of the sectors and the extent to which they project into the path of copying light.

Abstract: A copier has a movable housing which accommodates a support for an original to be copied, a source of illumination for the original, a lens system for forming an image of the original and a support for photosensitive material which is to receive the image. The housing has an opening in one of its sides and carries a hinged lid for lighttight sealing of the opening. A reflector is pivotally mounted inside the housing in the vicinity of the opening and can be moved between an operative position in which it intercepts the image from the lens system and an inoperative position in which it does not. When an image of normal size is required, the reflector is in its inoperative position and the image is projected onto the photosensitive material located inside the housing. When an image of large size is required, the reflector is brought into its operative position and the opening in the housing is uncovered.

Abstract: Apparatus for removing dust from the flat surfaces of stationary or moving sheets, webs, plates or similar objects has a unit which converts a low-pressure laminar air stream into a pulsating air stream. The pulsating stream contacts the surface of an object simultaneously with ultrasonic radiation. The direction of flow of the pulsating air stream, which can be ionized, may be parallel with or at right angles to the direction of propagation of ultrasonic radiation.

Abstract: Apparatus for positioning sheet-like or strip-shaped originals in a photographic copying machine has a horizontal table with a large window for transmission of copying light and a removable or exchangeable holder on the table. The holder has a lower section which rests on the table and has a first opening in register with the window, an upper section one marginal portion of which is pivoted to the corresponding marginal portion of the lower section, which is movable to and from an operative position of overlap with the lower section and which has a second opening in register with the first opening when the upper section assumes its operative position, and an elastic hold-down device which is affixed to the upper side of the lower section and has an open-sided cutout in register with the first opening.

Abstract: A photographic copying machine wherein any one of a series of masks, each having a differently dimensioned light-transmitting opening, can be placed onto a locating plate which supports a battery of fixedly mounted or mobile magnetic actuators for discrete electric switching elements. Each mask carries a different array of soft magnets which displace or otherwise influence a group of actuators so that the thus influenced actuators open or close the associated switching elements which adjust the exposure controls and/or another system of the copying machine in dependency on the size and/or shape of the opening in the selected mask. The soft magnets on each mask influence a different group (e.g., a different number) of actuators each of which is an H-shaped permanent magnet.

Abstract: A photographic copying apparatus wherein a composite mask is installed between the plane of photographic paper and a variable-focus optical unit which images a light source or an original into the plane of photographic paper. The movable sections of the mask carry pairs of photodiodes. A control unit adjusts the optical unit when the latter projects light onto both photodiodes of each pair in a direction to reduce the projected image and in the opposite direction when none of the photodiodes are illuminated. The adjustment is terminated when the size of the projected image is such that only one diode of each pair is illuminated.

Abstract: Apparatus for convoluting a web of photographic material onto a rotary core in a lighttight cassette has an elongated channel which is pivotably mounted in the cassette and whose outlet is normally tangential to the peripheral surface of the core. The outlet of the channel is detachably or permanently connected with a flexible or deformable strip-shaped element in the form of a link chain, plastic band, textile band or metallic band which surrounds a substantial part of or the entire peripheral surface of the core. When the leader of a web is introduced into and advanced beyond the outlet of the channel while the core rotates in a direction to convolute the web, the foremost part of the leader penetrates between the core and the flexible element and adheres to the peripheral surface of the core not later than upon the making of approximately two convolutions. During winding, the flexible element insures that the neighboring convolutions of the web on the core are tightly packed against each other.

Abstract: The longitudinally transported strip passes and is pressed between two cooperating transport rollers. The rotation axes of the two rollers are normally parallel to each other. One roller is swingably mounted about a swing axis which intersects and is perpendicular to the rotation axis of the other, non-swingable roller. Edge sensors are displaced by the lateral edges of the transported strip, when the strip improperly shifts transversely. The force thusly exerted upon an edge sensor is transmitted, via a force-multiplying lever system, to the swingable transport roller, swinging the latter to a position such that the swung transport roller exerts upon a major surface of the transported strip a force whose transverse component is directed opposite to the direction of the improper transverse shift, resulting in automatic recentering.

Abstract: A rotary format-mask carrier plate carries a plurality of removably supported format masks for originals to be copied and carries them back and forth between the copying station and a change station, where the masks can be exchanged for others and/or copied originals replaced by not yet copied originals. Downwardly extending projections on the format masks extend through and beyond corresponding openings in the rotary carrier plate. While a format mask is transported from the change station to the copying station, it rests on the carrier plate. When it reaches the copying station, the carrier plate descends an amount such that the projections on the format mask come to rest on correspondingly arranged stationary electromagnets, thereby transferring the weight of the format mask to the stationary electromagnets. The carrier plate drops a further amount, losing physical contact with the format mask at the copying station.

Abstract: Apparatus for transferring photosensitive sheets from the transporting plane into the copying plane of a photographic copying machine has a suction chamber with a perforated cover having a flat upper side which defines the copying plane. The interior of the suction chamber is subdivided into one or more centrally located primary sections which are in direct communication with the intake of a suction pump and two or more secondary sections which communicate with the primary section or sections by way of narrow passages defined by internal partitions of the suction chamber so that a sheet which is advanced in the transporting plane to a position of register with the cover is attracted first to that portion or those portions of the cover which overlie the primary section or sections and thereupon to those portions of the cover which overlie the secondary sections.