Abstract: In one example, a method of debris removal includes pressurizing a chamber to displace an elastic top surface of the chamber upward, and modulating the pressure of the mass of air within the chamber to cause the elastic top surface to oscillate in response. When the elastic top surface has been installed on the top surface of a vehicle (e.g., a semi-trailer), such oscillation may be used to impart movement to debris that has accumulated on or over the elastic top surface and remove such debris from the vehicle.

Abstract: A lithographic apparatus includes a position controller configured to control a position of a patterning device in its planar direction by selectively pressing at least one of the side faces of the patterning device. The position controller includes a gas pressure supply and one or more outflow openings directed towards at least one side face of the patterning device so as to exert pressurized gas on this side face in order to control the position of the patterning device in its planar direction in a contactless manner.

Abstract: Apparatus and method for contact printing uses a vacuum contact plate and a screen frame to hold a master film sheet in contact registration with a screen having a region that is substantially porous to the passage of air disposed about a central photosensitive region. The vacuum contact plate receives the screen frame and supports the master film sheet and the screen on an elevated, substantially planar component. Air is evacuated from a hollow cavity within the elevated component to create a pressure differential across the master film sheet to urge the master film sheet in contact with the screen. If the master film sheet is not large enough to cover the entire porous region of the screen, the master film sheet is attached to a carrier sheet of sufficient size. The carrier sheet is then placed on the elevated component to be retained in contact registration with the photosensitive screen.

Abstract: Vacuum frame apparatus is provided for maintaining precise registration between and an image forming sheet to be reproduced and a light sensitive sheet adapted for controlled exposure to light. The apparatus includes a light transmitting glass panel having a planar surface for contact with the image sheet and a vacuum blanket assembly including a blanket of thin, flexible sheet material adapted to contact the light sensitive sheet and bias the sheets toward the planar surface of the glass panel while maintained in precise registration. The vacuum blanket assembly includes a peripheral edge seal around the blanket for sealing engagement with the planar face of the glass panel and means for evacuating the space inside the peripheral edge bead between the planar face of the panel and the blanket of the vacuum blanket.

Abstract: A vacuum blanket apparatus for maintaining precise registration between an image forming sheet and a light sensitive sheet when subjected to controlled exposure to light passing through a glass panel includes a vacuum blanket having an upper cover of flexible sheet material adapted to contact the light sensitive sheet for biasing the same and said image sheet toward a planar face of the glass panel when the panel is locked in position parallel to the vacuum blanket. The blanket cover is formed with at least one elongated slot for receiving one or more registration pins for registering the image forming and light sensitive sheets. At least one deformable resilient pressure element in the slot is deformable to bias the sheets toward the glass panel.

Abstract: A slide track, pin registration system for registering photosensitive media to light exposure equipment. The system includes one or more slide tracks and each of which contain media registration pins. The slide tracks are orthogonally mounted within grooves let into a resilient media support mat. Each pin is restrained in a spring biased retainer which retainer is loosely confined in a support base that slide mounts to the track. The number of pins and profile shapes are variable to match the media and registration requirements. In one vacuum system, the tracks are supported in a multi-chambered, foam backed bladder. In another the tracks are supported on a single chambered bladder. In still another system, the retainer slides within grooves formed in a rigid board.

Abstract: Disclosed is a method for increasing the resolution in contact printing operations by ensuring an intimate contact between the mask and photoresist. A flow of air is directed at the underside of the workpiece being printed while the mask is in place to provide pressure for the necessary contact.

Abstract: A vacuum blanket for holding a sensitive sheet of material in precise registration with a film master against a rigid transparent plate includes a blanket of thin, flexible material having at least one vacuum port therein and an inside face opposing the rigid plate and adapted for biasing the sensitive sheet and film master toward the rigid plate in precise registration with one another. A flexible perimeter seal is provided around the edges of the blanket for sealing off a vacuum chamber established between the blanket and the plate when air is withdrawn through the vacuum port. A bladder of thin, flexible sheet material is secured to the outer surface of the blanket with a plurality of spaced apart seams forming a plurality of separate, inflatable air chambers on the outside surface of the blanket.

Abstract: A vacuum printing frame includes a backing plate; a pressurizable bladder assembly positioned on the backing plate, the bladder assembly including a lower wall positioned on the backing plate, a plurality of partitions sealed around lower edges thereof to the lower wall and defining a series of interconnected, nested chambers arranged in alignment from and pressurizable from a head end to a foot end of the vacuum printing frame, and a plurality of holes in each partition at positions close to the securement of the respective partition to the lower wall to provide fluid communication between adjacent bladder chambers; a flexible, fluid impervious membrane positioned above the bladder assembly for supporting a mask and photosensitive sheet; a transparent plate movable between an open position for permitting the mask and photosensitive sheet to be positioned on the membrane, and a closed position for sandwiching the mask and photosensitive sheet between the membrane and the transparent plate in an evacuation reg

Abstract: A vacuum contact system has a vacuum contact frame including a bi-layer blanket having top and bottom layers spaced apart by a number of parallel strip members to define a first space. A bead is positioned around the outer edges of the top layer to support a glass plate so that a second space is formed. Vacuum connectors communicate with the second space and a further vacuum connector communicates with the first space, all the connectors being connected to a vacuum pump. The first and second spaces have the atmosphere therein controlled by electromagnetic valves located in a vacuum circuit with the pump.In operation a film master and a presensitized material are located in the second space and the vacuum circuit is arranged to remove air from both the first and second spaces so that the two layers of blanket are drawn together. Ridges formed by the strip members are thus formed in the top layer outer surface and these ridges press the film master and presensitized material against the glass plate.

Abstract: An improved contact photo vacuum frame includes a specially constructed inflatable bladder which backs up the pressure blanket. The bladder is divided into a plurality of interconnected compartments by means of partitions, arranged in such a way that the compartments inflate sequentially, progressively forcing the air from between the contacting photo films in a predetermined pattern, insuring more intimate contact between the films. Alternative embodiments provide specific inflation patterns. A vacuum source can operate simultaneously to evacuate the volume between the film layers.

Abstract: Apparatus and method are disclosed for use in contact printing information from a master record carrier onto a replicate material of a type that emits a gas during the contact print exposure (e.g., a diazo film emulsion). Even though the master record carrier and the replicate material are pressed together by a pressure pad (e.g., a rubber diaphragm), it has been discovered that the emitted gas causes the master and replicate devices to separate slightly and that strain forces in the pressure pad are transmitted to the replicate material causing relative movement of the master record carrier and the replicate material during the contact print exposure. To limit such relative movement, a preferred embodiment of the present invention provides an isolating member disposed between the master-replicate sandwich and the pressure pad.

Abstract: A step-and-repeat registration system is disclosed for making multiple-image plates for use in flexographic printers or the like. The negative which carries the image to be transferred to a light-sensitive film, is referenced with respect to a fixed frame. An incremental step registration system accurately positions the film at a succession of predetermined stations to bring different portions of the film opposite the negative. At each station the film is brought into contact with the negative and an exposure is made on the pertinent film portion, using a light source to project the image onto the film. The registration system provides high accuracy and lends itself to partial or complete automation.

Abstract: A plunger assembly for pressing together two smooth layers of material against a firm planar supporting surface without entrapping air between the layers. The assembly includes a soft resilient pad having adjacent surfaces disposed at an obtuse angle and meeting at a ridge. The pad is pressed against the material to first engage the ridge and then the adjacent surfaces progressively outwardly from the ridge to sweep air from between the layers of the material.