Abstract: A backlighting system for a liquid crystal display (LCD) unit includes a first number of light emitting diodes (LEDs) configured to produce saturated radiation and a second number of LEDs configured to produce desaturated radiation, wherein the saturated and desaturated radiation is combined to form a resultant desaturated radiation of a target color. In a preferred embodiment, the colors and intensities of the first and second numbers of LEDs are chosen to produce a blue-green color of a typical vacuum fluorescent (VF) display unit, whereby the LCD unit may be used to simulated a typical VF display. By utilizing the concepts of the present invention, known dispersive effects associated with the LCD unit are minimized, and a substantially uniform light output from the LCD unit results regardless of a viewing angle relative to the normal of the viewing side of the LCD unit.

Abstract: An automotive gauge has a two part housing containing a stepper motor arrangement or other gauge movement which drives a pointer shaft. The front housing part consists of a transparent material for conducting light from a lamp to a facet which reflects light to a pointer for pointer illumination. The lamp is mounted inside or outside the housing. The front housing part includes an aperture for accommodating the pointer shaft and also has integral pins which serve as supports for rotary parts of the mechanism. The housing is mounted on a circuit board or a circuit board may comprise the rear housing part. Another embodiment uses a common light pipe member for the front housing of several gauges.

Abstract: A coil is wound on a bobbin having posts extending from the bobbin body, the end of the coil wire being wrapped on the posts to form wire terminations. The coil is mounted on a circuit board with the coil either above the board or suspended alongside the board edge. The periphery of each post is positioned against a solder pad of the circuit board and the wire termination is soldered to the pad. Each post has a flexible neck portion to relieve stress due to coil thermal expansion. A recess in the side of the post facing the solder pad enhances solder interaction with the wire termination.

Abstract: A high frequency AC probe signal is applied to one coil of a stepper motor to induce a signal on the other coil. The induced signal varies in amplitude according to rotor position. The stepper motor is driven by a microprocessor in microsteps. The position of a mechanical stop is determined by monitoring the induced signal while driving the rotor to the stop. When the induced signal no longer changes in amplitude the number of the last microstep yielding movement is recorded as the rotor position corresponding to the stop position. Also by measuring the induced signal at each microstep over a whole rotor rotation and the signal when the rotor stops, a more precise value of the stop position is determined by interpolation. Alternatively, the flip back position of the gauge and thus the stop position is determined on the basis of the induced signal.

Abstract: A rotary gauge driven by a stepper motor has a stop near the zero point of the gauge graphics. A factory calibration procedure rotates the gauge field in reverse direction to move the gauge pointer against the stop and continues field rotation until the rotor becomes unstable and flips back in the forward direction, and then moved to a rotor rest position. The angle of flip back, the rest position and the number of steps to the zero position are stored in non-volatile memory. In the vehicle, when the ignition is off, the microprocessor or the stepper motor wakes periodically and exercises the gauge, using the stored values to reset the gauge to the stable position. When ignition is turned on, the microprocessor moves the gauge directly to the zero position.