Abstract: An overhead projector comprises a base, a hollow post extending up from the base and a projection head on an upper portion of the post. The projection head comprises a light source, an objective lens and a deflection mirror. A power supply unit housed in the post supplies power to the light source and to a ventilating fan inside the post between the power supply unit and the projection head. Openings in the post provide for circulation of cooling air by the fan over both the light source and the power supply unit. The power supply unit includes interchangeable input stages which can be plugged into a socket in the post to adapt the power supply unit to different voltages and currents. A slide or microfilm projector mounted adjacent the projection head projects on the base an image which is then re-projected onto a wall or screen by the projection head. For use at conferences, a conference table top is provided with a plurality of sockets into which the posts of overhead projectors can be plugged.

Abstract: A device for holding film in a projector is disclosed, in which the film is loosely held between two transparent plates, and air is supplied between one of the transparent plates and the film, so as to clamp the film to the other transparent plate. Thereby the film is gently and positively held, and is also cooled.

Abstract: A film gate for image projection apparatus provides improved structure for directing cooling air across the surfaces of supported film. The outlets of the cooling air conduits are located adjacent edges of supported film and configured and oriented to create Coanda effect attachment of their issuing air streams to the film surfaces.

Abstract: The present invention is a single station type ionization smoke sensor which operates on a dc battery having a voltage lower than the voltage of about 9 volts usually needed for operation of ionization-type smoke sensors. The smoke sensor of the present invention includes a voltage booster means for boosting the battery voltage, a voltage detector means which detects when the boosted voltage falls below a predetermined value and an alarm energization means which energizes an alarm when an ionization type smoke detector means detects combustion products or when the voltage detector means detects a drop in the boosted voltage below the predetermined voltage.

Abstract: A projector comprises a base carrying a working surface for matter whose image is to be projected and a side stand on which a casing is mounted, extending over the working surface, the casing having a two part lamp housing with the upper part carrying a reflector and the lower part movably mounted with respect to the upper part carrying a condenser lens, a lamp being positioned between the reflector and the condenser.

Abstract: A lamp assembly and power module is provided for a microform display apparatus, such as a fanless microfiche reader. The lamp assembly and power module are both situated in a drawer which is removably inserted into the base of the reader to form an air-restricted path for the efficient convection of heat away from the reader. By setting the lamp at an angle to the longitudinal axis of the drawer, both the lamp assembly and power module components can fit in the drawer. The front end of the drawer is provided with a grille for air passage, and a chimney structure is situated adjacent the rear of the drawer for the efficient evacuation of heat. The lamp and power module are located below the chimney, and as the lamp and power module components heat the surrounding air, the air rises up the chimney and out of the reader by convection. This air movement creates a draft through the grille in the front of the drawer, which serves to sufficiently cool the components.

Abstract: A lamp assembly and power module is provided for a microform display apparatus, such as a fanless microfiche reader. The lamp assembly and power module are both situated in a drawer which is removably inserted into the base of the reader to form a air-restricted path for the efficient convection of heat away from the reader. By setting the lamp at an angle to the longitudinal axis of the drawer, both the lamp assembly and power module components can fit in the drawer. The front end of the drawer is provided with a grille for air passage, and a chimney structure is situated adjacent the rear of the drawer for the efficient evacuation of heat. The lamp and power module are located below the chimney, and as the lamp and power module components heat the surrounding air, the air rises up the chimney and out of the reader by convection. This air movement creates a draft through the grille in the front of the drawer, which serves to sufficiently cool the components.

Abstract: A projector for projecting a successive series of pictures and, in particular, an audiovisual information device, includes a housing, a projector disposed within the housing and a projection face which is provided in close proximity to the rear side of the housing for azimuthal projection. The projector face can be viewed by at least one window opening provided on the front side of the housing and the projector is arranged outside of the viewing range between the window opening and the projection face. The projector has a projection axis which is disposed at an angle with respect to the optic axis of its lens. The projector is especially suitable for both indoor and outdoor use.

Abstract: A still projector having a closure plate covering a housing aperture providing access to a projection lamp has a storage chamber within the housing positioned to be covered by the closure plate when the closure plate closes the aperture and to be accessible when the closure plate is removed from the aperture. The storage chamber is shaped to receive and store a spare projection lamp and preferably also a lamp changing tool. The closure plate is preferably a slide plate fitting flush with an exterior surface of the housing and extending over a cooling fan and its drive motor. The closure plate prefereably has air passage slots located over the fan, and the storage chamber is preferably formed as a depression in the projector housing over the drive motor.

Abstract: A film handling apparatus blower system. The system includes a blower having a high-pressure, low-volume section and low-pressure, high-volume section. The high-pressure, low-volume section is a scroll-type centrifugal blower with a circular impeller of cellular material to minimize discernible noise, an axial intake port, and a high-pressure outlet port. The high-pressure outlet port is coupled to a duct which directs the output high-pressure air flow into a film cassette. The low-pressure, high volume section is also a scroll-type centrifugal blower having a bladed fan wheel, an axial intake port, and three low-pressure outlet ports. One low-pressure outlet port is coupled to a duct which directs output air flow to a location for flow adjacent the rearward portion of a projection lamp. A second low-pressure outlet port is coupled to a duct which directs output air flow to a location for flow adjacent the frontal portion of the projection lamp.

Abstract: A spherical shell mounted on a base for pivoting movement about a diameter has a first aperture in which a frosted groundglass screen is mounted parallel to the pivot axis. Images are sequentially projected on the screen from the vertically upright beam of a cassette-type sound projector by a deflecting mirror. Cassettes are inserted in and withdrawn from the projector through a second aperture subjacent the first aperture. The perforated cover normally closing the second aperture carries the loudspeaker of the sound system. Cooling air is blown on the projector lamp from bottom openings of the shell by a fan arranged between the shell and a bracket on which the projector rests.