Abstract: Electrodes for a single ended arc discharge tube in which the electrodes diverging from the foil leads are generally concave towards each other between the lead-in wire ribbons and the free ends thereof from which the arc is drawn, the electrodes being spaced apart a greater distance at the point of entering the envelope than the distance between the ribbons.

Abstract: A compact lamp unit and associated socket for use in a projection system such as a slide projector, microfilm viewer, and so forth. The lamp unit includes a reflector molded from a plastic material and an electric lamp secured within the reflector. In order to decrease the axial dimension of the reflector and to avoid the use of pin connectors, electrical contacts for the lamp are pressed into recesses formed in the outer surface of the reflector. The reflector includes an opening at its apex through which electrical leads from the lamp extend outwardly of the reflector. The electrical leads are secured to the contacts by being forced into the recesses along with the contacts. This construction technique is fast and simple.The lamp unit also includes a handle to enable a heated lamp unit to be replaced by the user and a guide means to enable the lamp unit to be oriented quickly and accurately upon insertion into the socket.

Abstract: A compact lamp unit and associated socket for use in a projection system such as a slide projector, microfilm viewer, and so forth. The lamp unit includes a reflector molded from a plastic material and an electric lamp secured within the reflector. In order to decrease the axial dimension of the reflector and to avoid the use of pin connectors, electrical contacts for the lamp are pressed into recesses formed in the outer surface of the reflector. The reflector includes an opening at its apex through which electrical leads from the lamp extend outwardly of the reflector. The electrical leads are secured to the contacts by being forced into the recesses along with the contacts. This construction technique is fast and simple.The lamp unit also includes a handle to enable a heated lamp unit to be replaced by the user and a guide means to enable the lamp unit to be oriented quickly and accurately upon insertion into the socket.

Abstract: The concave reflecting surface of a projector lamp reflector is shaped in the form of a plurality of radial bands and a plurality of concentric circular bands to provide a multiple faceted surface for spreading the image formed by the reflector into a larger and smoother pattern and reducing the amount of imaging of a lamp filament and support post in the projected light pattern. Longer life and improved reproducibility of the molding tool are achieved.