Abstract: The invention relates to novel oligonucleotide arrays.

Abstract: A method of producing an object by successive solidification of layers of a powder material is disclosed. The method provides a preformed base plate having a metal plate with a solidified layer of a powder material formed thereon. Then, successive layers of said powder material are applied and solidified on the solidified layer of the base plate to form the object. In further detail, the method for produces a three-dimensional by providing a support and a preformed base plate having an upper surface for supporting the object. The base plate is removably attached to the support. Means are provided for adjusting the elevation of said upper surface. A layer of the powder material is applied to the upper surface of the base plate. The powder material is solidified at points corresponding to a cross-section of the object by irradiation with electromagnetic or particle radiation. Then, the applying and solidifying steps are repeated for completing the object.

Abstract: In a method for producing a three-dimensional object wherein the object is generated by successive solidification of individual layers of the object from a liquid or powdery material by action of electromagnetic radiation, the problem arises that the object is either distorted due to shrinkage of the material or that the quality of the surface of the object is poor when using a corresponding shrinkage reducing construction. For the solution of this problem, each layer is separated in an inner core region (2) and an outer shell region (3) and the action of the radiation is controlled in the core region and in the shell region for generating different properties of both regions.

Abstract: An apparatus for producing a three-dimensional object by successive solidification of layers of a solidifiable material (7) at places corresponding to the respective cross-section of the object by means of radiation is provided whereby the apparatus comprises a support (4) for supporting the object (6) to be formed, a coating device (12) for applying layers of the solidifiable material (7) onto the support (4) or a previously solidified layer, a solidifying device (14) for solidifying the layers of the material (7) at places corresponding to the respective cross-section of the object and a heating apparatus (8) disposed above the support (4) in operational position for heating the solidifiable material (7), the heating apparatus (8) comprising at least one straight radiant heater (81) with a varying heating power along its length.

Abstract: In order to achieve a homogeneous density distribution in a layer to be solidified of a three-dimensional object produced by laser sintering a laser beam is passed across the surface of the layer to be solidified, whereby the travelling speed of the beam varies as a function of the length of lines of a line pattern.

Abstract: An apparatus for layerwise production of an object using laser sintering by solidifying a material which is solidifiable by electromagnetic radiation comprises a device (5) for producing an electromagnetic beam (6) and a focusing device (8) for focusing the beam (6) onto the material within a working plane (7), whereby the focusing device (8) comprises a lens (9) and a mount (10) holding the lens (9), a ring nozzle (12) arranged adjacent to the image-side surface (11) of the lens (9) facing the working plane (7), the ring nozzle having its outlet oriented relative to the image-side surface (11) so that a discharged stream strokes tangentially along the image-side surface (11) towards the center, the inlet of the ring nozzle being selectively connected with a source of pressurized gas.

Abstract: In a method for calibrating the deflection control of a laser beam a light-sensitive medium (5) is exposed to a laser beam (2) at predetermined positions for generating a test pattern (20), thereafter digitized partial pictures of pattern portions (21) of the test pattern (20) are produced and the digitized partial pictures are composed to a digitized overall picture of the test pattern (20). The correction data for the control (4) for deflecting the laser beam (2) are calculated on the basis of a comparison of actual positions of the laser beam (2) on the digitized overall picture with predetermined desired coordinates.

Abstract: An apparatus for producing a three-dimensional object by successive solidification of layers of a powder material at points corresponding to a cross-section of said object using electromagnetic or particle radiation comprises support means having an upper side for supporting the object thereon at a determined elevation, elevation adjustment means for varying the elevation, means for applying a layer of the material onto the upper side or onto another layer formed on the upper side, and irradiation means for irradiating the layer of the material at the points corresponding to a cross-section of the object. For reducing the production time of the object the apparatus further comprises a prefabricated base plate on the upper side, the base plate being made of a material which the powder material adheres to when being solidified, and means for removably connecting the base plate to the upper side of the support means.

Abstract: When producing an object by subsequent solidification of material layers 1 at places corresponding to the object there is a problem of limited production speed because the scanning speed or laser power of the light beam scanning the material layer 1 cannot be increased at will, if the light beam 4 used for solidification is focused as required for exact resolution. According to the invention this problem is solved by providing a variable focusing device 8 in the light beam 4, whereby the focus of the light beam 4 can be varied during the solidification of the layer 1. Thus, a different focus, laser power and scanning speed can be used in different regions of the layer 1.

Abstract: In an apparatus for producing a three-dimensional object by laser sintering the object is produced by successive solidification of layers of a powder material at points corresponding to a cross-section of said object using radiation for solidifying said powder material. The apparatus includes a support having a substantially plane upper side for supporting the object, a material applying device for applying a layer of the material onto the upper side or onto another layer formed on the upper side, and a solidification device for solidifying a layer of the material by irradiation. The material applying device has a coating device and a drive for displacing the coating device in a direction parallel to the upper side of the support.

Abstract: An apparatus for producing an object using stereolithography includes a container, a bath of a liquid or powder material filling the container and having a free surface, the material being solidifiable under the action of electromagnetic radiation, a support for positioning the object relative to the free surface of the bath so as to form a layer of the material adjacent to the free surface, a device for solidifying the layer using electromagnetic radiation, a wiper device extending along a first direction across the free surface and drive means for moving the wiper device across the free surface along a second direction.

Abstract: In a method for producing a three-dimensional object wherein the object is produced layer by layer by applying a layer of a material which can be solidified by irradiation with electromagnetic radiation and subsequently solidifying the layer at the points corresponding to the object by irradiation the problem is encountered that the production process is considerably delayed by long heating and cooldown times within the apparatus used for the production. According to the invention this problem is solved by irradiating and thereby solidifying in each layer a region of the material surrounding the object so as to produce a container wall (26) for the material (21).

Abstract: In a method and an apparatus for producing three-dimensional objects by layerwise solidification of a material the problem is encountered that, in particular when using powdery or pasty material, a material layer having an exactly adjusted thickness can not be generated in a sufficiently fast manner. In order to solve this problem, it is proposed to scrape the material by means of a vibrating wiper member (21, 22) when applying the material or to provide a movable container (13) used for applying the material with such wiper members (21, 22) at the lower side thereof.

Abstract: An apparatus for producing an object using stereography is disclosed. The apparatus has a bath of liquid material in a container, the bath having a free surface. A support in the container supports and positions the object relative to the surface. A means for applying electromagnetic radiation solidifies a layer having solidified sections of the material. A wiper extends across the surface in a first direction. The wiper is at least partly formed of a flexible material and has a substantially horizontal lower edge, and it is positioned below the free surface of the bath in a working position. Displacement means displaces the wiper in the working position in a second direction substantially transversely to the first direction to move a portion of the liquid material in the bath. The lower edge of the wiper is flexibly yielding so as to apply a thin film of liquid material on a surface of the solidified layer and liquid material between solidified sections when displacing the wiper in the second direction.

Abstract: A method for producing an object by layerwise solidification of the object by means of electromagnetic radiation is expedited by simultaneously solidifying the material of a layer at a plurality of places.An apparatus for carrying out the method comprises an irradiation device (11, 12, 14, 15, 16) generating a plurality of beams (20, 21, 22) as well as a control device (7, 17, 18, 19) directing each of the plurality of beams independently to different regions of the layer (8a . . . 8d).

Abstract: In a method for producing a three-dimensional object by successive solidification of superposed layers of the object a deformation of the object caused by shrinkage during the solidification shall be reduced. To this end first of all respective partial regions (6a . . . 6k) of a layer are solidified and simultaneously connected with underlying partial regions of the previously solidified layer to form multilayered cells and thereafter adjacent partial regions of the same layer are interconnected by solidifying narrow connecting regions (8a . . . 8p). The intermediate regions (7) between the individual partial regions are solidified by post-curing.

Abstract: The present invention provides a resonant power converter for changing the magnitude of a DC voltage. The converter includes a common magnetic core with three legs (an "EE" core). The core has primary and secondary windings wound onto a first outside leg, and a tank winding and control windings wound onto a second outside leg. Control switch means are provided for effecting alternate pulses of current flow through the primary winding to effectuate alternate flux flow, the control switch means and the primary winding having a predetermined parasitic capacitance with a predetermined delay time between the termination of a given pulse and initiation of the succeeding pulse. The secondary windings are oriented to conduct alternately in phase with the alternate flux flow, there being inherent in the first leg of the transformer a magnetizing inductance, such that the magnetizing current will be great enough to charge said parasitic capacitance in a controlled fashion.

Abstract: A three-dimensional object is modelled by solidifying superposed layers in such a manner that on an already solidified layer a following layer of initially liquid or powdery material is solidified by light action or the like in correspondence with the form of the object.

Abstract: A surface contamination monitor which discriminates between different types of surface contamination and irregularities is provided with a horizontal sensing plate, a light detector positioned under the plate, a narrow bandpass filter disposed between the plate and the detector, and optical lenses. At one end of the sensing plate is included three laser diodes, while at the other end is located a coupling prism. Beams from the laser diodes strike the coupling prism and are directed at different angles so as to either strike the exposed surface of the sensing plate or become trapped within the sensing plate. Variations in the reactions of the different beams to different contaminants and irregularities on the exposed sensing plate surface allow the light detector to discriminate between dust, molecular films , and scratches and craters on the exposed surface.

Abstract: An apparatus for measuring the water content of an object to be measured comprises in combination a pair of optical filters for obtaining from the same source light a reference light having a wavelength not easily absorbed therein and a measuring light having a wavelength easily absorbable therein, an optical system for irradiating the object with the reference and measuring lights, an photoelectric converter for converting the reference and measuring lights to electrical signals, a temperature detector for detecting the temperature of the optical filters, a humidity detector for detecting the humidity of optical paths for the reference and measuring lights, extending from the optical system to the object, and a water content-measuring circuit for finding the quantity of water contained in the object on the basis of output signals produced from the photoelectric converter, temperature detector and humidity detector.