Abstract: The light output of a fluorescent lamp is controlled and optimized. Both the light output and the lamp voltage peak at nearly the same value of mercury cold spot temperature. Controlling the lamp voltage therefore controls the light output. Thus, when the lamp voltage is continually monitored, any decline from the peak voltage is detected and a signal is generated which reverses the instant mode of operation of a cooling device placed in proximity to the lamp cold spot. With the cooling mode reversed, the lamp voltage will rise towards the peak. The cooling mode remains unaltered until the lamp voltage falls again.

Abstract: The light output of a fluorescent lamp is controlled and optimized. The light output of a lamp peaks at some optimum value of mercury cold spot temperature. During operation the lamp output is continually monitored, any drop in peak light output is detected, and a signal is generated which reverses the instant mode of operation of a cooling device placed in proximity to the lamp cold spot. With the cooling mode reversed, the light output will rise towards the peak. The cooling mode remains unaltered until the light output falls again.

Abstract: The phosphor light output of a fluorescent lamp is controlled and optimized. The phosphor light output of the lamp corresponds to a particular level of either the vapor mercury or rare fill gas contained within the lamp envelope. This gas emission level is initially determined for a given system; a monitoring circuit thereafter detects any deviation from this level, generates a signal and sends it to a controller. The controller adjusts the operation of a mercury cold spot temperature-regulating device causing the cold spot temperature to increase or decrease until the optimum temperature and hence lamp phosphor light output is reestablished.

Abstract: An optical system is provided for a reproducing machine which scans an object to be reproduced, utilizing a pulsing light source to illuminate successive incremental portions of the object. The ray reflected from the scanned image is directed along an optical path onto the imaging plane. The scanned image is directed onto the imaging plane by a reflector element which has an active slit formed on its surface. The reflector element is positioned an optimum distance from the imaging plane such that the image is defocused at more than one magnification ratio.

Abstract: A low pressure gas discharge lamp is provided with a pair of high power incandescent electrodes to increase output illumination at the lamp ends. In an alternate construction, the electrodes are of high power, low emissivity and are electrically connected to a second pair of high emissivity electrodes which provide the means for enabling the mercury discharge. With this second construction, the low emissivity electrodes can act as ballast for the circuit.

Abstract: A tubular arc low pressure discharge lamp is disclosed which has its end electrodes connected through the lamp envelope then to the tube pins. This permits the electrodes to be physically located closer to the lamp ends and decrease end illumination falloff.

Abstract: An incandescent lamp such as a tungsten filament lamp in which the filament is a series of alternate active coil sections and inactive straight sections. The surrounding glass envelope is correspondingly drawn down around the straight sections to reduce the volume of the envelope and to provide mechanical support for the filament.