Abstract: A glass stage for use as an upper stage in an overhead type projector system. The glass stage includes a rectangular frame body having substantially the same dimension as that of a lower stage of a projector, a lower transparent plate fixed to the rectangular frame body, and an upper transparent plate which pushes a strip film onto the lower transparent plate. The upper plate is rotatably supported by brackets provided on the frame body. Each of the brackets is provided with a longitudinal hole which engages with hinge pins for guiding movement of the upper transparent plate in a drawing direction thereof. The longitudinal hole is provided with a portion inclined downwardly at an end of a pushing side of the upper transparent plate. The rectangular frame body is provided at one side portion thereof with small holes through which the upper stage-fitting pins are to be snugly fitted.

Abstract: A liquid crystal display device for an overhead projector has a light-transmissive liquid crystal display cell sandwiched between protective plates both from above and below. At least one of these protective plates is separated from the cell surface to form an air passage provided with a fan such that air can be caused to flow therethrough and come into direct contact with the cell. The cell can thus be cooled efficiently and the light of the projector can be increased for projecting a clearer image.

Abstract: An overhead projector comprises a housing having a top comprising a Fresnel lens and a writing plate overlying the Fresnel lens. A light source in the housing directs light up through the Fresnel lens and writing plate. A support arm projecting up from the rear of the housing supports an objective lens and a deflection mirror in position to project light from the writing plate onto a wall or screen. A liquid crystal indicating or display device overlies the writing plate and is spaced from the writing plate to provide an air flow space between the writing plate and the liquid crystal indicating device. A fan or blower in the projector housing draws air through the air flow space between the liquid crystal indicating device and the writing plate to cool the liquid crystal indicating device and also produces air flow in the projector housing to cool the light source and other components in the housing. The projector may also have a computer and keyboard for controlling the liquid crystal indicating device.

Abstract: Transparency medium for automatic printers comprises transparent film sheet with central window area and surrounding margin area and a backer sheet bonded to the film sheet only in the margin area. Preferably, a sequence of such backer sheets, including side edges suitable for automatic feeding (such as by tractor pin holes) on a separate edge portion, are separably connected at adjoining forward and rearward edge lines to form a fan folded supply of indefinite length.

Abstract: A portable overhead projector has a top surface which slopes downwardly from the rear wall to the front wall and includes stops on the top surface adjacent to the front wall for preventing a transparency from sliding off the top surface during use and to preset the distance of the leading edge of the transparency from the bottom edge of the protecting wall.

Abstract: A holder for a plurality of overhead projection system transparencies includes a ruler-like bar provided with suction cups for attaching the bar to the stage of the projector and U-shaped arms for engaging the holes provided along one edge of each transparency. The rear legs of the arms are rotatably received in bosses provided along the rear edge of the bar and the front legs releasably engage posts at the front edge of the bar.

Abstract: An image projection system having a built-in mechanism for changing unframed transparencies comprises a frame, a source of illumination, a projection lens, a stage mounted to the frame for positioning a transparency thereon for view, delivery means for gripping and slidingly moving an unframed transparency along the surface of said stage, a magazine holding a stack of unframed transparencies for insertion into the frame adjacent to said stage, feed means for feeding the uppermost transparency from a stack of transparencies in the inserted magazine, and suitable drive means. A second magazine and second feed means can be included in the system for bedirectional changing of unframed transparencies. An electrical logic circuit interfacing with a control module can be included in the system for control. The mechanism for changing unframed transparencies can be isolated and built in a detached unit for use with a conventional image projector which does not have such a built-in mechanism.

Abstract: A registry device for transparencies for an overhead projector comprises a backbone with at least two projections for entering openings in a transparency to prevent it from moving; and, an adhesive-free anchoring sheet of plastic attached to the backbone. The anchoring sheet being of a material that will cling to the glass stage of a projector and prevent the registry device from sliding or being moved until the anchoring sheet is lifted from the glass. In a preferred embodiment a framing sheet also is attached to the backbone.

Abstract: A device for supporting a transparency on a top surface of an overhead projector is foldable from a compact unit into a structure having a planar base with an indentation for receiving a transparency and legs which are pivotally mounted on the base and rest on the top of an overhead projector to position the transparency at a specific spacing therefrom. Other pivotal elements position a lens at a given distance above the base so that light from the overhead projector will pass through the transparency and project it on a remote screen without white light showing around the sides of the transparency.

Abstract: A method and a device for presentation of information on a plurality of sheetshaped information carriers (5) which are connected to each other in a continuous series of the sheets which are folded relative each other so that the series of sheets extends zig-zag like and forms in a storage position a pack of sheets in which the sheets are connected to each other and from which the sheets can be folded out for presentation of information on the sheets. One of the outer sheets (5) of the pack is placed with an interspace relative to the pack, which is substantially a multiple, larger than 1, of the width of each sheet between said folding lines. In this way at least two sheets at a time can be held unfolded on a base in said interspace for the purpose of presentation. The series of sheets can consecutively be brought over to the outer sheet, forming a new pack during a consecutive positioning of the sheets in the interspace for the presentation.

Abstract: An overhead projector transparency transport system uses a transparent platen 20 extending over projection window 11 and beyond both sides of projector 10. A transparent belt 80 made of a base web 84 and a pocket web 85, fused together to form a series of pockets, receives a sequence of transparencies 100, and transverse fold lines formed between pockets 81 allow belt 80 to fan fold. Pocket web 85 is fused to base web 84 at inturned edges 95 of an open side 96 of each pocket 81 to trap a transparency 100 within its pocket, once inserted. Platen 20 is positioned so that transparent belt 80 can advance across platen 20 from a fan-fold supply stack 82 next to projector 10 and proceed to an automatically formed take-up stack 83 next to the other side of projector 10.

Abstract: The invention relates to a device for facilitating the handling of transparencies to be projected by an overhead projector. The device includes a support frame which can be secured by adhesive means to the light table of a projector. A transparency is placed on the support frame, and extends across an aperture in the frame through which light is projected upwardly. An aperture cover which encloses the support frame is mounted thereon for reciprocating movement between a position covering the aperture to a position exposing the aperture. Accordingly, the aperture cover enables the projected light to be interrupted when a transparency is being changed on the support frame.

Abstract: A protecting device (1) for transparencies (8) intended for overhead projection and pivotably mounted about a swivel pin (9) in the protecting device (1) is provided in the form of an unfoldable file. This file comprises a bottom cover (2) shaped as a rectangular frame with a transparent window (5) and comprising side members (6,7) secured thereto and situated at opposing rim portions. The swivel pin (9) is mounted in one side of the frame, preferably adjacent one corner of the frame, and in such a manner that it extends substantially perpendicular from said frame. The transparencies (8) are provided with a gripping register (10a, b, c) and are collated in a swivel cover (11) so as to be turned out individually, said swivel cover being pivotably mounted about the swivel pin.

Abstract: In an overhead projector comprising a writing plate, and under this arranged Fresnel lens, a light source and an objective carried by a carrying arm, the problem to be solved is to overcome the disadvantages of the state of the art and to provide a possibility for a lecturer to make information retrieved from an electronic information source, for example, a computer or an electronic game, accessible to a large viewer and listener circle. The invention solves this problem thereby, that between the Fresnel lens and the writing plate there are arranged a layer of liquid crystals which are aligned in an electric field and transparent electrodes on both sides thereof, whereby two of the plates or films traversed by the light beam have light polarizing properties.

Abstract: An accessory for use with an overhead projector comprises a platen which has a generally rectangular, transparent central portion and an opaque peripheral portion bounding the central portion. In the region of peripheral portion the platen has two mutually orthogonal, upstanding ridges, each extending substantially the entire length of the corresponding side of the central portion and each being defined by a pair of opposed inner and outer ridge-defining surfaces. The inner ridge-defining surfaces of the two ridges serve to locate a plurality of superimposed transparencies in register with each other and with respect to the central portion. The outer ridge-defining surfaces of the two ridges each form a guide surface for guiding a highlighting strip, or an occlusion or revelation screen.

Abstract: A protecting device (1) for transparencies (8) intended for overhead projection and pivotably mounted about a swivel pin (9) in the protecting device (1) is provided in the form of an unfoldable file. This film comprises a bottom cover (2) shaped as a rectangular frame with a transparent window (5) and comprising side members (6,7) secured thereto situated at opposing rim portions. The swivel pin (9) is mounted in one side of the frame, preferably adjacent one corner of the frame, and in such a manner that it extends substantially perpendicular from said frame. The transparencies (8) are provided with a gripping register (10a, b,c) and are collected in a swivel cover (11) so as to be turned out individually, said swivel cover being pivotably mounted about the swivel pin.

Abstract: An extension platform for holding a book of transparencies in an operative position on an overhead projector includes a body member adapted to receive and hold a pack of transparencies, at least two suction cups positioned on the underside of the body member for attaching and securing the body member to the stage area of an overhead projector and wedge-shaped fulcrum means located under the body member which translates the downward gravitational force of the weight of the pack of transparencies into an upward pull on the suction cups. In another embodiment, the extension platform is attached to part of a book of transparencies.

Abstract: Storage device for sheets, which are intended to be exposed particularly microfilms, which device comprises a case in the form of a sleeve substantially rectangular in form and with an elongated substantially rectangular cross-section, in which case a space is provided and forms an elongated opening at one end of the sleeve, the space enclosing a number of envelopes and between the envelopes intersheets, the envelopes being slidable between a position substantially entirely within said space and protected by the sleeve and an outer position extending out through the opening and with the main part of the envelope outside the sleeve, in which outer position stopping means are provided to prevent the respective envelope to be entirely drawn out from the sleeve and removed from the same, the intersheets being fixed in the sleeve against sliding movement, the envelopes being made of transparent material and intended to store the sheets which have to be exposed in said outer position.

Abstract: An envelope for transparencies for overhead projectors comprises a substantially rectangular pocket of transparent plastic sheet material. The pocket is open along at least one side edge for insertion of the transparency to be presented therebetween. At least one opaque flap is attached in a foldable manner along one of the longitudinal side edges of the pocket, said flap being attached to and spaced a distance from the longitudinal edge such that holes may be punched in the sheet material along said side edge between the flap and said edge and that in the unfolded position the flap covers the longitudinal side edge and in the folded position it exposes said longitudinal side edge and any holes to permit storage in a binder, file or the like.

Abstract: A box structure having a light source therein and a light transmission panel on the front thereof to receive X-ray films thereon for viewing with back-light illumination is provided with a horizontal cross bar detachably secured across the light transmission panel at a predetermined vertical position to divide the viewing screen into upper and lower viewing areas. The bottom of the cross bar is provided with a portion for detachably retaining a film edge for viewing of a film in the lower viewing area, and shades are horizontally secured at the top or bottom of the front of the box structure and are vertically drawable to cover at least an underlying portion of the light transmission panel to reduce glare.

Abstract: An over head projector has a standard projection lens for projecting the whole view of an original image and a partial projection lens for projecting a part of the original image in enlarged scale. One of the projection lenses is selectively brought to a projection position for projecting the original image onto a projection screen. A stage for supporting the original image is vertically movable and is moved up and down when the projection lens is changed. The selection of the projection lens and the vertical movement of the stage are associated with each other so that the original image is always at a proper position with respect to the focal length of the selected projection lens.

Abstract: Disclosed is a device for the insertion of microfiche cards into a microfiche reader comprising a plurality of microfiche cards, each card having an image aperture part and a blank part with a perforation in one of the two corner areas of the blank part, a magazine containing a plurality of microfiche cards, the magazine being equipped at a location corresponding to the perforation of the microfiche card with a shaft, releasable from the magazine, the shaft extending through the perforations in the microfiche cards as a holder and a rotational axis for movement of the microfiche cards, and being open on a first lateral surface adjacent the shaft and on a second lateral surface perpendicular to the first lateral surface and facing away from the shaft, a film stage and magazine stage arrangement adapted for receiving the magazine wherein the magazine is positioned on the magazine stage such that the first open lateral surface of the magazine is pointing toward the film stage and the distance between the shaft a

Abstract: A picture plate changer for changing pictures projected with a large scale picture projector, e.g., overhead type projectors projecting a single picture from an entire picture plate. A magazine stores the picture plates as a stack of flat plates or plexiglass each placed in horizontal slots or tracks in the changer. The stack of plates are vertically shiftable to selected disposition so that a desired entire picture is accurately indexed to a location just above the level of the projector plate and interconnectors on each frame selectively cooperate with a mechanism which can engage and shift a selected picture and frame from the magazine to the projector and back. Power mechanisms and control means are shown to enable selection and operation of the changer in a pre-determined manner. Devices on the changer and the picture plates assure accurate positioning for projectors.

Abstract: A film screen is perpendicularly slidably mounted on a first guide rail in a microfiche reader. This first guide rail is detachably mounted on a frame which in turn is slidably mounted on a second guide rail perpendicularly with respect to said first guide rail so that the two guide rails form a coordinate support arrangement for selectively displacing the film screen in two mutually perpendicular directions. The second guide rail is mounted on the base of the microfiche reader. The film screen and first guide rail can be easily detached from the frame and replaced by a film screen and first guide rail of different size which is then attached to the frame.

Abstract: An apparatus designed for the purpose of viewing transparencies on an overhead projector is disclosed. The apparatus incorporates a frame and the transparencies are retained by a portion of the frame defining a mounting member. Substantially all of the weight of the frame is concentrated in the mounting member and a member in opposed, spaced relationship to the mounting member. Tabs extending from the mounting member into the area circumscribed by the frame, in which area the transparencies are positioned for storage and display, serve to retain the transparencies in relative alignment.

Abstract: A system for creating projected visual motion effects for filming or videotaping, with the use of still projection equipment, involves projecting a still image on a screen from a slide projector, projecting a second image on the screen, superimposed on the first image, and causing the projected second image to move rectilinearly at a controlled variable speed and in a selected direction over the first projected still image. This movement is accomplished with a "crawler" assembly having a transparent rectilinearly movable carrier panel carrying the second image over the stage surface of a standard overhead projector, or a light box, constituting the second image light source. The illuminated second image is directed to the screen by an overhead lens and suitably angled mirror. The transparent carrier is driven by a variable-speed reversible motor through a changeable worm gear drive assembly coupled to friction drive rollers engaging the carrier, which is slidably supportingly retained in a guide frame.

Abstract: An overhead projector comprises a stage having at least two guide members fixed to its upper surface and movable longitudinally and transversely above a projector body, a file page having a plurality of slide films fitted therein in rows and columns and pairs of reference edges spaced apart at equidistances from crosswise and lengthwise center axes of the file page and adapted to abut against the guide members of the stage for positioning the file page relative to the stage, and positioning means for determining movements of the stage at determined intervals. The slide films in the file page are spaced apart at distances correspondingly equal to the movement distances determined by the positioning means. The projector is capable of correctly positioning a file page relative to the stage with ease after the file page has been rotated or turned upside down for changing over the projection methods of the projector, such as reflection projection and transmission projection.

Abstract: A system for previewing and projecting slides that are stored in spaced, co-planar relation in a planar holder is disclosed. The slides are previewed, either individually or in a group, in their natural orientation without removing the slides from the holder. Projection of the slides to form a naturally oriented image also is accomplished without removing the slides from the holder. In the preferred embodiment, means are provided for moving the planar slide holder orthogonally with respect to the optical axis of the projection system. A slide indexing system is provided to allow the projectionist to select a particular slide for projection. The slide indexing system utilizes cooperative means on the slide holder and projector to achieve indexing and, if desired, other control functions. In an alternative embodiment, the projected image plane is vertical and can be rotated about a vertical axis at the projector without moving the base of the projector.

Abstract: An improved frame construction for supporting transparencies for projection by an overhead optical projector, including means for maintaining a transparency in fixed position relative to the projector, and means for selectively adding color to desired areas of the transparency for directing the attention of the viewer, and adding interest to the display. The colored areas may be oriented in either of two mutually perpendicular directions.