Abstract: Improved apparatus are diclosed for stepwise, layer by layer fabrication of three-dimensional objects by irradiation of radiation-curable materials, in which the critical steps of fast and efficient deposition of thin, flat layers of material covered with a radiation-transmitting film, as well as careful separation of the film upon irradiation, are achieved by using a reciprocating carriage that during its motion changes the elevation of the film. When the carriage is moving in one direction, the film is being laid down forming a layer, and when upon irradiation the carriage is returning, it is peeling the film off without distorting the formed layer. Improved apparatus are provided that build the whole object on an open platform without using a container or form each layer above container.

Abstract: An improved method of preparing three-dimensional objects from uncured photopolymer by depositing the photopolymer in layers and treating it with radiation to convert the photopolymer into a cohesive structure capable of being at least partially unsupported includes irradiating the uncured photopolymer by transmitting radiation through a constrained radiation transmittent flexible film. Apparatus for performing the method is disclosed.

Abstract: An improved apparatus forms three-dimensional objects in layers by modulating irradiation of liquid photopolymers, either stepwise by alternating photopolymer deposition and irradiation, or continuously by simultaneous deposition and irradiation. Photopolymer is deposited onto open, unfenced and uncontained, substrate and is contained by a photopolymer wall formed around the object simultaneously with it by supplemental irradiation, for providing to irradiated layer unobstructed access critical to apparatus simplification, automation, fabrication time and to feasibility of continuous forming. To decrease drastically fabrication time, whole layer is irradiated simultaneously using masks photoplotted on a roll of film or a matrix of miniature individually controlled components tightly packed similar to liquid-crystal displays, with shrinkage distortion minimized by constraining the irradiated photopolymer surface and/or by solidifying infinitely thin surfaces in continuous mode.

Abstract: In general and in one preferred method, a diaphragm plate may be formed by providing a vessel containing a quantity of a light-transmittive first photopolymer compound which includes, as mixed constituents, a reactive oligomer resin, a reactive monomer diluent and a photoinitiator. A first unmasked surface of the compound is irradiated with ultraviolet (UV) light for solidifying the surface to a depth equal to the relief thickness, i.e., the desired diaphragm thickness. A second surface of the compound is irradiated with UV light subsequent to being covered with a opaque mask which defines the shape of the diaphragm. This irradiation completes the formation of the diaphragm plate by solidifying the remaining, unmasked quantity of compound. The unsolidified compound is then removed from the masked area of the plate. Other preferred methods are also disclosed.

Abstract: An apparatus (9) is disclosed for determining the volume of liquid (18) in a container (1) which is being provided with an in flow and an out flow of liquid such that there normally remains an ullage volume (8) in the container filled with gas. A timer (13) actuated valve (11) is provided for interrupting one of the in flow and the out flow of liquid. A pressure sensor (10) detects the pressure of the gas in the ullage volume (8) of the container (1) during the interruption of the one of the in flow and out flow of the liquid, and a microprocessor (14) calculates the volume of liquid (18) in the container (1) from the detected change in pressure of the gas during the interruption.

Abstract: An improved method of forming three-dimensional objects comprises irradiating an uncured photopolymer by emitting an effective amount of photopolymer solidifying radiation directly into a desired area inside of uncured photopolymer using an immersed radiation guide. The radiation is emitted through a material which leaves the irradiated surface capable of further cross-linking so that when an adjacent area is irradiated, it will adhere thereto. Repeating the irradiation for all areas in desired sequence, any three-dimensional object can be made; depending on the size of the emitted beam and the amount of emitted energy, objects can be formed point by point, post by post, area by area or layer by layer.

Abstract: An improved method of forming three-dimensional objects comprises irradiating an uncured photopolymer by transmitting an effective amount of photopolymer solidifying radiation through a radiation transmittent material which is in contact with the uncured photopolymer. The transmittent material is a material which leaves the irradiated surface capable of further cross-linking so that when a subsequent layer is formed it will adhere thereto. Using this method multilayer objects can be made.