Abstract: The disclosed data communication equipment (DCE) provides full-duplex, split-speed data communication over 2-wire dial-up telephone circuits, typically between a host processor and data terminal equipment (DTE). A telephone line interface includes low speed and high speed modems that establish a low-speed DTE-to-Host communication channel and a high-speed Host-to-DTE communication channel for split-speed full-duplex data communication. An I/O interface interfaces the DCE to the Host/DTE I/O ports at selectable asynchronous I/O speeds (typically symmetrical). A communications processor provides buffering and control functions, and implements split-speed data communication in accordance with the high-speed and low-speed communication protocols. In addition, the communication processor provides data compression for the high-speed channel, and error checking and retransmission for both the high speed and low speed channels. The DCE telephone line interface network is switchable between Host and DTE modes.

Abstract: A dual mode, digital servo positioning system controls servo motor current by a processor-generated current control set point in conjunction with velocity feedback. When the motor has advanced to the vicinity of a target position, the processor opens the velocity feedback loop and reduces servo amplifier gain, such that the set point controls motor current without velocity feedback. This open loop condition provides a springy servo response that eliminates oscillation due to small deviations from target position caused by electronic drift or gravity. Position information is provided to the processor by means of quadrature encoded tachometer pulses from the motor.

Abstract: The disclosed CRT overlay, which is mounted to the display face of a CRT, comprises an overlay panel (typically a non-glare optical filter) mounted at its edges to the CRT display face and a layer of transparent glass beads interposed between the overlay panel and the CRT display face. The glass beads maintain a thin (in the range of 0.005 inches or less) gap between the overlay panel and the display face, such that display clarity is substantially unaffected by the mounting of the overlay panel. The use of the glass beads enables the overlay panel to be mounted without a relatively expensive bonding process, while at the same time avoiding the display clarity degredation associated with currently employed air-gap mounting techniques.

Abstract: A lockbox is provided for a word processor printer output bin attached to a printer. The lockbox, which is insertable and removable from the output bin, is locked in the bin upon insertion, and can only be removed by disengagement of a first locking means. The lockbox has a security door which is positioned in a paper receiving position upon insertion into the output bin and which must be closed in order to remove the lockbox from the output bin.

Abstract: A scanning mechanism is provided for scanning individual output bins for receiving documents from a paper printer. The mechanism determines each bin's availability for receiving documents, the degree of fullness and whether or not a lock box is positioned in the bin for receiving designated documents.

Abstract: A connecting and alignment mechanism for printer output module cabinets having facing adjacent wall members, comprising vertical positioning male-female docking channels and lateral positioning docking pins and recepticles.

Abstract: A time-variable illumination control apparatus for a lamp permits light intensity to be gradually increased starting at a predetermined time. The intensity control includes a clock-timer to initiate time-variable power supply network. The illumination control apparatus is designed for use on mornings when a user would commonly arise before daylight. By setting the illumination control apparatus to gradually increase the light intensity of a lamp prior to awakening, the lamp simulates sunrise so that the eyes gradually adjust to the light while sleeping. Upon awakening, the eyes are fully adjusted to the light and eye discomfiture from a sudden increase in intensity is avoided.

Abstract: The disclosed optical data link provides full-duplex, high-data rate optical communications between geographically separate data processing facilities by means of identical optical transceivers. Transmitter optics include an LED and a collimating Fresnel lens for providing a collimated, modulated light beam. Receiver optics include a focusing Fresnel lens and a photoreceptor for converting the impinging modulated light beam into corresponding electrical signals, which are amplified by a gain-controlled amplifier. The LED is selectively translatable along its optical axis to provide focal length correction for temperature-induced focal length distortion, while the photoreceptor is selectively translatable along its optical axis to provide, in addition to focal length correction, a preselected amount of optical energy attenuation.

Abstract: A peak detecting network utilizes a passive integrating filter to translate the peaks of an input signal into zero crossings of a translation signal, while providing a high degree of noise rejection and preventing the build-up of a DC component in the translation signal. The peak detecting network includes a sine pulse-forming filter comprised of a parallel cascade of a DC shunt inductor, a plurality of series LC sections, and a terminating capacitor. The series LC sections are characterized by respective transfer functions whose impulse responses are substantially finite time duration sine pulses of a successive number of cycles. A rectifier network applies a rectified input signal to the sine pulse-forming filter. A buffer network taps the response of the LC section associated with a one-cycle sine pulse impulse response. The resulting translation signal has a positive-going zero crossing corresponding in time to the occurrence of a peak of the rectified input signal.