Abstract: A broadcast data distribution system collects, edits, verifies, formats and distributes real-time (dynamic) and non-real-time (static) data.A central database is maintained and updated continuously. Data in the central database is continuously broadcast to an unlimited number of subscribers, each having receiving apparatus and a local database. In normal data traffic situations, real-time data messages are broadcast as they are received. In heavier data volume situations, newly received data messages are compared with last-known values for the particular data record being updated. If the change is determined to be significant, the update message is broadcast; otherwise, it is not. In extremely heavy data traffic volume situations, real-time data messages are not broadcast.The invention ensures that the subscribers' local databases are current, even when real-time data messages are not being generated, or are only being generated for data records whose values have changed significantly.

Abstract: A projection and viewing apparatus having a hollow housing with an open top and front and back walls is also provided with an optical system carriage which is mounted within the housing for rotational movement with respect to the housing. This carriage is capable of rotation from an upright position to a substantially horizontal position. The carriage is composed of a lower portion which is mounted to the housing for the rotational movement and an upper portion which is pivotally mounted with respect to the lower portion so as to be able to move from an extended position in which the upper and lower positions define the operational carriage, to a retracted position in which either the upper or lower portion is withdrawn into the other. Provision is made for locking the upper and lower portions together in the extended position. The lower carriage portion is provided with a depth dimension which is no greater than the distance between the front and rear walls of the housing.

Abstract: A system for producing images of documents is disclosed. The system provides varying levels of illumination to different areas of the document being recorded, depending upon relative image densities across the document. A slit aperture image area is divided into a plurality of illumination zones and the image density of each zone is sensed and adjusted individually. Efficient and orderly unattended off-loading of photographed documents is accomplished by a movable drawing member over which large documents are automatically draped, properly collated. A catch tray is provided for automatically off-loading and collating smaller documents.

Abstract: A roll of film is formed without a spool or core and the innermost end of the roll of film is formed into a closed loop of predetermined diameter. In a film viewing device, in which film is normally transported from a supply shaft to a take-up shaft, the supply shaft is provided with an adaptor which is mounted thereon for rotation therewith and is resiliently biased to be radially expandable from a diameter smaller than to a diameter larger than the predefined diameter. The roll film structure is mounted on the adaptor and the resilient biasing of the adaptor then forces it radially outward against the closed loop and securely holds the roll film for take-up.

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: An optical projection apparatus having foldable mirror members which permit the apparatus to be folded into a rigid, compact assembly for ease of installation and transportation. The apparatus comprises a double triangulated optical mirror structure which is interdependently mounted with the projector and screen without reference to the base section. The double triangulated structure provides the required optical rigidity while also folding or collapsing of the apparatus to reduce critical outer dimensions.