A system for delivering light from a light source to a digital micro-mirror device. The system includes one or more lens groups. At least one lens of the system is laterally displaced, so that its optical axis is not centered on the chief ray of the system.
An apparatus for rotary encoding includes a knob configured to be rotated. The apparatus also includes multiple switches each configured to selectively form or not form a connection based on a current rotational position of the knob. The apparatus further includes a controller configured to generate or use a digital value associated with the current rotational position of the knob. The digital value is defined by which switches have or have not formed connections. Locations where the switches form the connections are selected such that the digital values uniquely identify different rotational positions of the knob and are non-sequential as the knob is rotated.
G01D 5/252 - Selecting one or more conductors or channels from a plurality of conductors or channels, e.g. by closing contacts a combination of conductors or channels
G01D 5/34 - Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
G05G 1/08 - Controlling members for hand-actuation by rotary movement, e.g. hand wheels
An apparatus includes one or more light emitting diodes (LEDs) configured to be coupled to a power supply and to generate illumination, such as to generate a reticle in an optical scope. The apparatus also includes a first switch coupled in series with the one or more LEDs. The first switch is configured to selectively activate and deactivate the one or more LEDs based on whether the first switch is turned on or off. The apparatus further includes a low power detector configured to sense a low power condition of the power supply and to repeatedly turn the first switch on and off in response to the low power condition to cause the one or more LEDs to blink. The low power detector is configured to turn the first switch on and off at a given rate, and the given rate increases as the power supply is depleted.
A pulse-width modulation (PWM) light source drive for driving a light source is provided that includes a microcontroller, a modulation element, a voltage regulator, and a light detector. The microcontroller is configured to generate a PWM signal and an inverse PWM signal. The modulation element is configured to generate a drive signal based on the PWM signal. The light source is configured to be driven by the drive signal. The voltage regulator is configured to generate an output drive voltage for the light source. The light detector is configured to detect light energy emitted by the light source, to generate an optical power feedback signal based on the detected light energy, and to provide the optical power feedback signal to the voltage regulator during a laser-on driving interval. The microcontroller is configured to provide the inverse PWM signal to the voltage regulator during a laser-off driving interval. The voltage regulator is configured to adjust the output drive voltage based on the optical power feedback signal during the laser-on driving interval and based on the inverse PWM signal during the laser-off driving interval.