Abstract: Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

Abstract: A sliding seal system for providing a fluid seal that is slidable in two linear and one rotational degrees-of-freedom and that is flexible in one linear and two rotational degrees-of-freedom is disclosed. The sliding seal system includes a support member having a working surface arranged to provide a seal interface with a sealing surface on a first body. A flexible membrane is attached to the support member and coupled to a second body. A fluid supply system is provided to deliver a fluid to a region between the working surface of the support member and the sealing surface of the first body to provide buoyant flotation to the seal support member at the working surface. In a preferred embodiment, a fluid exhaust system is also provided to remove the fluid delivered by the fluid supply system. One particularly useful application of the described sliding seal system is in a photolithography system to provide a seal between an exposure apparatus and a wafer chamber.

Abstract: A reticle carrier used in semiconductor manufacture. The carrier includes a bottom cover and a top cover having a transparent window. A protective lid may also be included. The box includes ports to allow nitrogen gas to enter and purge the inside. The transparent window is used for inspection and photochemical clean. However, since no material is available which can suitably handle smaller wavelength radiation, the reticle is removed from the carrier when exposure at these wavelengths is required.

Abstract: An air bearing stage device which is suitable for use with a vacuum environment is disclosed. According to one aspect of the present invention, a stage apparatus includes a table that is positioned in a system vacuum chamber, a first rod that carries the table, and first and second plates that support the first rod. The first plate includes an air bearing surface that is held against the first side of a first wall by a first vacuum force. A first drive mechanism drives the first plate to move the first rod in a first direction, and also drives the second plate to move the first rod in the first direction, while a second drive mechanism which includes a second rod and a first linear motor causes the second rod to move the first rod in a second direction.

Abstract: In a wafer chuck for flatly vacuum-chucking a semiconductor wafer (11) supported by support pins (15) such that a pressure in a suction chamber (13) surrounded by an external wall (12), the upper surface of the external wall (12) is formed to be lower than the upper surfaces of the support pins, and the upper surface of the external wall (12) does not pressure the semiconductor wafer (11), a distance (L1) between the external wall (12) and closest support pins (15a) is up to 1.8 mm, and an alignment pitch (L2) of the support pins (15) aligned inside the closest support pins (15a) to the external wall (12) is not more than 1.5 times of the distance (L1) between the external wall (12) and the closest support pins (15a).

Abstract: The present invention aims at preventing deterioration of flatness of a substrate and contamination of a substrate-holding surface of a substrate holder, which are caused by a resist leaking into the back surface of the substrate. A substrate-holding surface of a substrate holder is provided with a first pair of grooves 31 and 32 extending from one end to the other along a scanning direction and a second pair of grooves 33 and 34 extending from one end to the other along a direction generally perpendicular to the scanning direction. The first and second grooves are positioned such that they make contact with the periphery of the substrate when the substrate is vertically or horizontally placed on the substrate holder. Even when a resist on a substrate leaks into the periphery of the back surface, the resist escapes into the grooves, thereby preventing deterioration of the flatness of the substrate or contamination of the substrate-holding surface.

Abstract: A board stage of an aligner that can avoid bending of a printed circuit board to be exposed and accomplish high accurate exposure. In one preferred modes a suction plate 2 having small holes 20 is mounted on a supporting body on which a space 30 bigger than the small holes is provided. The holes 20 are connected to the space 30 and to a vacuum device via an air passage 31 and a bottom passage 32. The diameter of the suction hole 20 is so less than 0.4 mm not to make at the printed circuit board such bending that causes exposure troubles.

Abstract: An apparatus for supporting a mask comprises a pair of members. The mask held against each member by a vacuum arrangement which prevents relative motion between the mask and members. The members are compliant such that they accommodate flatness variations in the mask but without deforming the mask.

Abstract: A supporting assembly for use in a lithographic projection apparatus includes a moveable member which is journalled in a housing such that substantially no vibration forces are transmitted between the moveable member and the housing. The assembly comprises a gas filled pressure chamber in which the gas in the pressure chamber acts on the moveable member so as to at least partially counteract the force due to the weight of the moveable member and any other object which it carries. The pressure chamber is supplied with gas and the whole assembly is constructed and arranged such that substantially no gas flows through the pressure chamber when the moveable member is substantially stationary. The supporting assembly may be applied to a lithographic projection apparatus, object table, or metrology frame.

Abstract: In addition to first and second pneumatic springs, first and second electromagnetic actuators are provided, and a target position and target speed of a stage are feed-forwarded to them. At this time, the first and second pneumatic springs and the first and second electromagnetic actuators divide a frequency band with predetermined filters.

Abstract: Disclosed is a scanning exposure apparatus in which laser light from an excimer laser is used and in which a reticle is illuminated by an illumination optical system with use of slit-like light. A patter of the reticle is projected onto a substrate through a projection optical system. The reticle and the substrate are relatively and scanningly moved relative to a widthwise direction of the slit shape. The illumination optical system is arranged to scan the laser light from the excimer laser and to define a secondary light source on a pupil plane of the illumination optical system. When the width of the illumination region is W (mm), the scan speed of the original and/or the substrate is V (mm/sec), and the time necessary for defining the secondary light source once is T (sec), a relation W/V=nT is satisfied, where n is an integer. This assures uniform projection of the reticle pattern on the substrate, through the scan exposure.

Abstract: A method and apparatus for holding recording media against a media support surface of an imaging system using an arrangement of variable cross-section vacuum grooves. Each vacuum groove has a continuously decreasing cross-section along its length. Each vacuum groove has a maximum cross-section adjacent a vacuum port and a minimum cross-section at a distal end of the vacuum groove.

Abstract: A plate with substantially constant thickness is used to compensate for the residual distortion in the image projected by a high-quality projection lens for lithography. The two surfaces of the plate have an identical aspherical profile, whose shape has been calculated using the measured distortion map of the lithographic objective. The figuring process applied to the plate uses the principle of polishing in the presence of an elastic deformation, so as to achieve the desired aspherical shape on both sides.

Abstract: A stage assembly and support system are provided to stabilize a stage base, such as a wafer stage base or a reticle stage base, minimizing forces transmitted from the stage assembly to a stationary surface, such as the ground, and thereby preventing vibration of other parts or systems in a wafer manufacturing process. Depending of the applicable photolithography system, a reticle stage and/or a wafer stage are accelerated in response to a wafer manufacturing control system to position the semiconductor substrates. The jerking motions of the reticle stage and/or wafer stage cause reaction forces acting on the reticle stage base and/or wafer stage base. The reaction forces induce vibration to the stationary surface and surrounding parts of the photolithography system. The wafer stage assembly and support system according to this invention allow the reticle stage base and/or wafer stage base to move relative the stationary surface.

Abstract: Stage devices are disclosed for use especially in a vacuum environment as encountered in a charged-particle-beam (CPB) microlithography (exposure) apparatus. An embodiment of the stage device includes a bottom plate that serves as a guide plate providing two opposing parallel edge planes that serve as respective guide planes. A top plate and a moving table are sandwiched between the guide planes. Extending from one edge of the moving table is a sample platform desirably configured to carry at least two objects such as two reticles or two wafer substrates. Between the top surface of the bottom plate and the bottom surface of the top plate are air pads that provide near frictionless motion of the moving table relative to the guide planes. The moving table is provided with multiple (e.g., three) linear motor coils that provide motion of the moving table in two dimensions relative to the guide planes (e.g.

Abstract: Stage devices are disclosed that include gas-actuation and reaction-force-canceling mechanisms. In an embodiment, an X-axis moving guide extending in the X direction engages a lower stage via a gas bearing. Y-axis sliders (movable elements) are provided at both ends of the X-axis moving guide. A Y-axis fixed guide 8 engages each Y-axis slider via a gas bearing. Each Y-axis slider and respective fixed guide constitute a respective pneumatic actuator. Respective mounting members are provided near the ends of each fixed guide, with interposed gas bearings, and each fixed guide is slidably affixed to a base plate. An actuator for stroke correction is provided in association with each mounting member.

Abstract: A vibration control method of a stage apparatus having a main stage body that is driven over a base plate, which controls vibration by providing a force to the base plate. The position of a center of gravity and a position of a major inertia axis of the stage apparatus is detected when vibration is applied to the base plate, and the force is controlled based on the detected position of the center of gravity and the major inertia axis. As a result, in this vibration control method, force is controlled based on the actual position of the center of gravity and the major inertia axis, which is determined when vibration is applied to the base plate of actual equipment or by simulation rather than based on the position of the center of gravity and the major inertia axis in a design model. Hence, residual vibration of the base plate is effectively controlled.

Abstract: A photographic paper magazine, for containing a photographic paper roll of photographic paper, includes a magazine case. A support shaft is contained in the magazine case in a rotatable manner, and secured to an axis of the paper roll in rotationally immovable manner. First and second flanges are disposed on the support shaft, for neatening end faces of the paper roll. A passageway is formed in the magazine case, for passage of the photographic paper in and out. 16 receiving pins are formed to project from and edge portion of the first flange toward the second flange, for defining a passage space between. The passage space allows passage of the photographic paper extending from the paper roll toward the passageway. When the support shaft is rotated in a winding direction, the 16 receiving pins temporarily wind a portion of the photographic paper extending out of the passage space.

Abstract: A hardcopy apparatus including a main roller and a loading mechanism to load a medium into the hardcopy apparatus, said loading mechanism including a vacuum holddown input unit to hold media down onto a surface of said holddown unit. In addition, a method of loading a medium into a hardcopy apparatus including a vacuum holddown unit, a driving roller and a secondary roller, comprises the steps of: manually positioning the medium onto a surface of the holddown unit; by rotating the secondary roller, advancing the medium towards the main roller; and engaging the medium to the main roller.

Abstract: Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

Abstract: The invention provides a maxiprint easel. An enclosure includes a focus board to support the photographic paper. The enclosure forms an interior, and the focus board forms a series of holes connected to the interior. A vacuum port connects a vacuum source to reduce pressure within the interior, such that suction through the holes forces the paper onto the focus board when there is reduced pressure in the interior. A vacuum cleaner can be used for the source in a home setting.

Abstract: A film support and feed system of a camera includes a pressure plate, a film feed mechanism which moves the film frame in a space in front of the pressure plate, a film suction mechanism which brings the film frame into intimate contact with the pressure plate by vacuum aspiration, a reversible motor, and an associating mechanism which selectively associates the reversible motor with either the film feed mechanism or the film suction mechanism in accordance with a direction of rotation of the reversible motor. The reversible motor is associated with the film feed mechanism by the associating mechanism to operate the film feed mechanism when the reversible motor is driven to rotate in a forward direction, or to operate the film suction mechanism when the reversible motor is driven to rotate in a reverse direction.

Abstract: A thermal transfer material is provided which has a support on which a light-to-heat conversion layer and an image forming layer are provided, wherein a smoothster value of the surface of the image forming layer is no more than 2 mmHg, and a center line average surface roughness Ra thereof is in a range of 0.03 to 0.2 &mgr;m. Also provided is a laser thermal transfer recording method in which the thermal transfer material and a thermal transfer image receiving material are laminated to each other to produce a laminate. Further provided is a laser thermal transfer recording method in which the thermal transfer material and a thermal transfer image receiving material are laminated to each other to produce a laminate, the laminate is irradiated with a multi-mode semiconductor laser, the thermal transfer material and the thermal transfer image receiving material are peeled from each other, and an image is thereby formed on the thermal transfer image receiving material.

Abstract: An exposure holding apparatus includes a substrate holding section for holding a substrate. The substrate holding section includes a thin film, which causes a photocatalytic reaction upon irradiation with light. This substrate holding apparatus prevents adhesion of foreign materials, which causes a decrease in yield of device production, and provides a system for rapidly removing the foreign materials.

Abstract: A substrate handling method includes a first step for holding a substrate with a hand mechanism, the hand mechanism being provided for positioning the substrate, a second step for discharging a gas out of a gas pad provided on a stage, such that the substrate held by the hand mechanism is floated relative to the gas pad, wherein the hand mechanism is provided separately from the stage, a third step for moving the hand mechanism such that the substrate is positioned finely with respect to the plane of the substrate and a fourth step for stopping gas discharging from the gas pad.

Abstract: In a stage device, prior to two-dimensional movement of a stage, a first driving device disposed on a side of the stage where an object is loaded drives the stage in a first-axis direction, and a second driving device disposed on a side of the stage opposite to the side where the object is loaded drives the stage in a second-axis direction that is different from the first-axis direction. Thus, the stage is moved in two-dimensional directions. Therefore, in order to perform two-dimensional movement of the stage, a structure is possible in which each driving device is defined as a one-dimensional driving device, and in which one driving device is not driven by another driving device. Therefore, it is possible to move the object at high speed and to accurately control the position of the object with a simple structure. By using the stage device in order to move the wafer or the like, an exposure device of high throughput and high accuracy can be realized.

Abstract: A projection exposure apparatus capable of detecting projection exposure conditions in the middle of a laser beam irradiation path. The apparatus includes a laser source for generating a laser beam, an illumination optical system for illuminating a reticle with the laser beam, a projection optical unit for projecting a pattern of the reticle onto a wafer, a light shielding member in which the path of the laser beam emitted by the laser source is enclosed and in which an inert gas is supplied, a removable enclosure for enclosing the light shielding member, an insertion slot formed in the light shielding member so that a detector for detecting a physical or chemical characteristic in the vicinity of the laser beam path may be inserted into the insertion slot, and a light shielding lid provided on the light shielding member. The light shielding lid can be opened and closed when the detector is inserted or removed.

Abstract: An exposure system for liquid photopolymer printing plates has a small movable illumination source. The illumination source moves to expose all of a photopolymer object, such as a printing plate being exposed. The area covered by the light source can be adjusted to match the area of the printing plate. The system does not require a large uniform source of illumination. The collimation of the light source is variable. This permits control over the cross sectional profile of exposed features in the photopolymer. Preferably a flat horizontal glass plate supported by air pressure supports the photopolymer being exposed. An optical sensor and a control system are used in preferred embodiments to keep the plate flat by controlling air pressure in an enclosure beneath the plate.

Abstract: An optical element (1) of an optical system has at least one chamber (5) that is sealed against atmospheric pressure and is enclosed by boundary surfaces and that has a fluid filling. At least one of the boundary surfaces of the chamber (5) is exposed at least partially to illumination light. It is configured so that a change in the fluid pressure inside the chamber (5) results in a change in non-rotational-symmetric imaging properties of the optical element (1) having n-fold symmetry. For this purpose, a fluid source has a fluid connection to the chamber via a fluid supply line (17). Furthermore, a control device is provided for the pressure in the fluid filling.

Abstract: A method and apparatus for holding recording media against a media support surface of an imaging system using an arrangement of variable cross-section vacuum grooves. Each vacuum groove has a continuously decreasing cross-section along its length. Each vacuum groove has a maximum cross-section adjacent a vacuum port and a minimum cross-section at a distal end of the vacuum groove.

Abstract: Spoke shaped (petal shaped) through holes or cavities are provided at the center or a substrate holder which attaches and holds a substrate over substantially the entire surface, to allow vertical movement of a center-up member having a plurality of radially extended spoke shaped mounting portions. As a result, degradation in the flatness of a substrate at the time of attaching the substrate to the mounting surface of the substrate holder is minimized.

Abstract: A platen surface structure construct, particularly useful in a hard copy apparatus for a vacuum holddown, is configured by dimensioning print media platen surface structure channels and ports in order to ensure print media leading edge and trailing edge holddown. Moreover, the vacuum is distributed across the platen surface in accordance with predetermined dye flow characteristics based upon known dye composition and known print medium composition and such that print artifacts are not created by vacuum pulling wet dye through the capillaries of the medium.

Abstract: Support device (53) provided with a first part (69) and a second part (71) which is supported relative to the first part by means of a gas spring (73) having a pressure chamber (75). A gas supply (117), which compensates for gas leakage from the pressure chamber (75) during operation, is connected to an intermediate space (119) which is in communication with the pressure chamber (75) via a pneumatic restriction (121). The gas pressure present in the intermediate space (119) is held as constant as possible during operation by means of a control loop (123), to prevent transmission of pressure fluctuations which are present in the gas supply (117) to the pressure chamber (75) as much as possible. Such pressure fluctuations are undesirable in the pressure chamber because they cause mechanical vibrations in the second part of the support device and the device to be supported.

Abstract: When a relatively thin substrate, such as a silicon wafer, is used in an exposure apparatus, a substrate adjuster is inserted between the thin substrate and the substrate holder in order to raise the position of the top surface of the thin wafer. The substrate adjuster is selected so that the sum of the thicknesses of the substrate adjuster and the thin substrate lies within the range of thicknesses of ordinarily used substrates. If a relatively thick substrate, for example, a ceramic substrate, is used, the substrate is directly held on the substrate holder without using the substrate adjuster. The substrate holder holds the substrate adjuster through vacuum adsorption, which also helps the substrate be adsorbed onto the substrate adjuster. In this manner, different substrates having different thicknesses can be used in the exposure apparatus without exchanging the substrate holder.

Abstract: A method and apparatus are provided for orienting a sheet of recording media on a support surface for recording an image onto the recording media in a predetermined location. A registration device, which includes two contacting points for contacting an edge of the media, establishes a registration axis having a know orientation and location with respect to the support surface and with respect to the image to be recorded. A media loading device advances the media across the support surface and orients an edge of the media against the two contacting points of the registration device. At least one of the two contacting points of the registration device is movable with respect to the support surface for adjusting the separation between the two contacting points in accordance with a width of the recording media. The image may also be located at a known location with respect to another perpendicular edge of the recording media.

Abstract: A projection exposure apparatus controls the position of a mask so that the mask is in a desired position without reducing throughput even if the size of the mask is increased. For example, a controller adjusts the pressure of air blown from air holes so that a reticle is floated at a desired distance above a reticle floating plate. The controller also controls the driving of linear motors having stators and sliders, thereby adjusting the pressing force of control bars in contact with the sides of the floating reticle to press the sides of the reticle and control the two-dimensional position of the reticle. Therefore, it is possible to control a mask so that the mask is placed in a desired position without reducing throughput.

Abstract: A thermal transfer image forming method using a laser is disclosed.

Abstract: Vacuum easel for releasably holding material. The vacuum easel includes a panel having a first sheet and a second sheet with a plurality of walls disposed between the first and second sheets. The walls define a series of progressively larger air pathways between the first and second sheets. A plurality of openings are formed in the first sheet to allow communication of air between the exterior of the first sheet and the respective air pathways. At least a subset of the openings are associated with each of the air pathways. A zone selector is operable to selectively communicate a source of vacuum with at least one of the air pathways to draw air from the exterior of the vacuum easel through the openings associated with the selected air pathway.

Abstract: A substrate holding system for holding a substrate by attraction through a negative pressure, has protrusions for supporting the substrate, including a primary protrusion of annular shape disposed around a substrate lifting pin and secondary protrusions distributed around the primary protrusions, and an arrangement for reducing a local change in shape of the substrate in a portion around the primary protrusion as the substrate is attracted by the negative pressure.

Abstract: A reference chuck which is used with a leveling device for holding microelectronic substrates and other electronic component substrates for laser ablation and other exposure processes, the chuck comprising a frame body for supporting the substrate to be processed, clamping means at the periphery of the frame body for holding the substrate to the frame body and elastomeric means for urging the substrate mounted in the reference chuck against the clamping means. The undersides of the clamping means which contacts the upper surface of the substrate forms in its tightened position a clamping plane which clamping plane is parallel with an established plane of the lower surface of the chuck. The reference chuck provides a very low profile envelope for use with conventional leveling devices and the top surface of the substrate and the lower surface of the reference chuck are in parallel planes when the chuck is placed on the working surface of the leveling device.

Abstract: A vacuum drum apparatus on which a mask is mounted having a resilient surface and an array of holes suitable for a substrate of a given size. The drum is a circular cylinder perforated with an array of holes. A hollow chamber within the drum is connected to a controlled pressure source for providing a vacuum. The mask may be magnetically attracted about the outer surface of the drum. Thus, the mask may be made of a flexible ferromagnetic sheet. The mask is preferably elastomeric and may include an inextensible layer.

Abstract: An improved vacuum exposure frame for use in making exposed aluminum printing or lithographic plates permits the use of unworked glass, preferably tempered glass, rather than polycarbonate plexiglass (which is easily scratched) of the prior art replacement of the transparent image-exposure-window material. The frame is routed on the lower aperture-facing portion of the exposure window, preferably by a 90.degree. routing having a horizontal face and a vertical face surrounding and defining the aperture underside. A preferred embodiment has a reverse depression preferably routed out of the horizontal face and a sealant-adhesive is inserted into the reverse depression and along the vertical face so as to secure the unworked glass to the frame. Separate ID windows with long lasting polycarbonate inserts are also in the frame where the main image exposure window aperture is shaped to contain preferably only the book pages to be exposed onto the aluminum plate.

Abstract: A carrier for photosensitive sheets of copy paper is cleaned to remove adherent paper particles. The carrier can be an endless belt in which case a cleaning member bears against the lower run of the belt. The carrier can also be a turntable. If the turntable is unable to move horizontally, a cleaning member for the turntable is mounted on a pivotal arm so that the cleaning member can be brought to the turntable. On the other hand, if the turntable is shiftable along a horizontal direction, the cleaning member can be stationary and the turntable is then moved to the cleaning member when the turntable is to be cleaned.

Abstract: Mask holders are disclosed for holding a mask used during a microlithographic exposure. The mask holder comprises an outer frame and an inner frame. The outer frame contacts the periphery of a main surface of the mask to hold the mask. The inner frame is connected to the outer frame, and contacts an inner portion of said main surface of the mask to hold the mask. The mask holder can include one or more electrostatic and/or vacuum chucks, a thermally conductive material that contacts the mask whenever the mask is being held by the mask holder, and/or an electrically conductive material to discharge accumulated electrical charge on the mask during use.

Abstract: An air-bearing imaging platen (20) for supporting imaging medium (40). The imaging platen (20) is comprised of an array of disks (62). Each disk has an air exit hole (64) in an approximate center of the disk (62) and a pneumatic system provides air to each disk. Air exits the hole (64) and flows in a radial direction across a surface (69) of the disk (64) creating a negative pressure in the area between the hole (64) and an edge (68) of the disk (62). The negative pressure holds the imaging medium (40) close to the hole (64), and the air flow provides a cushion which supports the imaging medium (40), thus insuring frictionless support while holding the image medium (40) in a curved shape. The air flow exits at the edge (68) of each disk. In various embodiments the contour of the surface (69) of the disk (62) may have various cross sectional shapes such as flat, conical, or spherical.

Abstract: A vacuum drum apparatus on which a mask is mounted having a resilient surface and a plurality of holes suitable for a substrate of a given size. The vacuum drum apparatus is balanced for rotation at high speeds by attaching a counterweight to the mask. The drum is a circular cylinder perforated with an array of holes. The drum has flat surfaces on its outer surface that are used to mount the mask and the substrate on the drum. A hollow chamber within the drum is connected to a controlled pressure source for providing a vacuum. The mask may be magnetically attracted about the outer surface of the drum. Thus, the mask may be made of a flexible ferromagnetic sheet. The mask may also be staged on the drum with other mechanical type entanglements. The mask is preferably elastomeric and may include an inextensible layer.

Abstract: An image media assembly comprising: a doner element, a receptor element, and means for maintaining the elements in a predetermined position wherein one element overlies the other, said means including a vacuum present between the elements.

Abstract: An exposure method for irradiating a mask from above the mask held in proximity to a substrate positioned below the mask to transfer a mask pattern of the mask to a photosensitive layer of the substrate by exposing the photosensitive layer to a light beam, includes the steps of using a gap-measuring device to measure a gap between a portion of the mask to be locally scanned and irradiated and a portion of the substrate to be locally irradiated, comparing a value measured by the gap-measuring device with a preset value, and locally deforming the mask and/or the substrate according to a difference between the value measured by the gap-measuring device and the preset value so as to cause the gap to approach a predetermined value.

Abstract: A vacuum drum apparatus on which a mask is mounted having a resilient surface and an array of holes suitable for a substrate of a given size. The drum is a circular cylinder perforated with an array of holes. A hollow chamber within the drum is connected to a controlled pressure source for providing a vacuum. The mask may be magnetically attracted about the outer surface of the drum. Thus, the mask may be made of a flexible ferromagnetic sheet. The mask is preferably elastomeric and may include an inextensible layer.

Abstract: A photographic printer for monoline printing on a photosensitive paper comprises an assembly for feeding and positioning the paper, a printing device for printing on the paper and a shearing member for shearing the paper. The feeding and positioning assembly comprises a first pair of opposed loading rollers and a second pair of opposed drawing rollers defining a paper transporting path of the photosensitive paper. At least the second pair of drawing rollers is mounted for rotation in forward and reverse directions and independently actuable in a stepwise manner. A buffer-stock chamber is disposed between the first and second pairs of rollers and is located in cooperation with the paper transporting path. A supporting member cooperates with an open end of the buffer-stock chamber to support the paper.