Abstract: A head up display or HUD system, including methods and apparatus, suitable for use in a flight simulator. According to the present teachings, a flight simulator HUD may be configured to produce a HUD image that appears superimposed on a simulated cockpit field of view image, and which has substantially the same relatively short focal distance from the user as the simulated image. A simulator HUD according to the present teachings does not require any holographic optical elements or an unrealistic cockpit volume, and provides an accurate simulation of conditions in a real aircraft cockpit.

Abstract: A head up display or HUD system, including methods and apparatus, suitable for use in a flight simulator. According to the present teachings, a flight simulator HUD may be configured to produce a HUD image that appears superimposed on a simulated cockpit field of view image, and which has substantially the same relatively short focal distance from the user as the simulated image. A simulator HUD according to the present teachings does not require any holographic optical elements or an unrealistic cockpit volume, and provides an accurate simulation of conditions in a real aircraft cockpit.

Abstract: In an integrated laser/FLIR rangefinder wherein the laser is injected into the visible optic path for transmission, a laser boresight mechanism comprises a light source for producing a light target, optic means for projecting the light target along the optical path of the laser beam, a switchable laser boresight retroreflector cube for switching into the visible optic path to reflect the light target back through the visible light optic path to the telescope field of view, and manual adjustment means for adjusting the optic means for aligning the light target and the recticle line of sight.

Abstract: A reflective afocal beam expander optical system is disclosed for transmitting electromagnetic (EM) energy. The beam expander, in the preferred embodiment, is comprised of a reflective afocal system including a section of a primary parabolic mirror, a section of a secondary parabolic mirror, and a beam splitter. The two mirrors have a common axis of rotational symmetry and a common focus point and the centerline of the incoming EM energy is displaced from the axis of rotational symmetry. The beam splitter is positioned with respect to the primary mirror to receive the edge rays of the EM energy and cause the EM energy to be folded and exit through a window while clearing all optical elements. A viewing system having a viewing axis through the beamsplitter allows a viewer to see through the same window as the exiting EM energy. A second refractive afocal optical system is made integral to the specific laser system being used in order to control beam expansion ratios.

Abstract: A closed loop electronic ignition system for internal combustion engines, in which a comparison is made between a signal derived from a fixed predetermined crank-shaft angle, and a signal derived from the commencement of the second stage of combustion within a cylinder of the engine, and if non-coincidence is detected between the two signals, the ignition timing is either advanced or retarded so as to maintain coincidence between the signals, so that the second stage of combustion always occurs at the fixed predetermined crank angle, the spark then being extinguished by switching the ignition coil "on" at this predetermined crank-shaft angle, irrespective of engine requirements.

Abstract: A closed loop electronic ignition system for internal combustion engines, in which a comparison is made between a signal derived from a fixed predetermined crank-shaft angle, and a signal derived from a predetermined point on the pressure rise curve after the commencement of the second stage of combustion within a cylinder of the engine, and if non-coincidence is detected between the two signals, the ignition timing is either advanced or retarded so as to maintain coincidence between the signals, so that the second stage of combustion always occurs at the fixed predetermined crank angle, the spark then being extinguished by switching the ignition coil "on" at this predetermined crank-shaft angle, irrespective of the speed and load on the engine, as well as all other parameters which can affect the ignition timing.

Abstract: An opto-electronic ignition system for an internal combustion engine in which radiation falls on to and is cut off from a photo-transistor in timed sequence with the engine, and in which between the photo-transistor and the primary winding of the ignition coil there is a plurality of switching Darlington pairs, each Darlington switching in inverse relation to its neighbor, and the first Darlington switching in inverse relation with the photo-transistor. The circuit is designed so that it will reliably operate in engine compartment temperatures above 125.degree. C.

Abstract: A device for generating a voltage pulse for use with a fuel injection system of an internal combustion engine utilizing infra-red radiation source and detector for obtaining a voltage pulse to operate the solenoids of the appropriate fuel injectors in cyclic order, which voltage pulse is timed from shutter means mechanically driven and interposed between the source and detector, the relative angular duration of the voltage pulse determined by the length of unmasking by the shutter, being controlled by the speed of and load on the engine.

Abstract: An opto-electronic ignition system for an internal combustion engine in which radiation falls on to and is cut off from a photo-transistor in timed sequence with the engine, and in which between the photo-transistor and the primary winding of the ignition coil there is a plurality of switching Darlington pairs, each Darlington switching in inverse relation to its neighbor, and the first Darlington switching in inverse relation with the photo-transistor. The circuit is designed so that it will reliably operate in engine compartment temperatures above 125.degree. C.

Abstract: In an ignition system of an internal combustion engine the provision of a device for fast switching the primary circuit, this device including an infra-red radiation source and an infra-red radiation sensitive element, the radiation path being interrupted in timed relation to the engine revolutions whereby switching current is provided which is amplified for fast switching transistorized elements and applied to the primary winding of the ignition coil. Advance or retard of the ignition system can be achieved in relation to speed and/or load conditions on the engine by altering the line of sight between the radiation source and the radiation sensitive element in relation to a device which interrupts the radiation in timed relation to the engine revolutions.

Abstract: The advance and retard of the spark ignition in an ignition system of an internal combustion engine is achieved electronically by generating two series of pulses in synchronism with the engine using one series as a reference for maximum advance and the other series to operate a counter to count down the requisite number of pulses beyond the maximum advance point before the spark is initiated, the count of the counter being varied from a computer in accordance with speed and/or load on the engine.