91results about How to "Extend lamp life" patented technology

An illumination control circuit allows a user to set a desired brightness level and maintains the desired brightness level over temperature and life of a light source. The illumination control circuit uses a dual feedback loop with both optical and thermal feedbacks. The optical feedback loop controls power to the light source during normal operations. The thermal feedback loop overrides the optical feedback loop when the temperature of the light source becomes excessive.

A high-power LED lamp uses an LED chip that can be larger than 1 mm square. The chip has trenches that can convert light trapped in the semiconductor into light that passes through a major surface of the chip. The trenches include light-reflecting tracks joined to a chip terminal and feeding a semiconductor layer. The chip can have triangular light emitting elements that improve light extraction from the semiconductor. The elements can be fused, resulting in improved manufacture yield of chips. A 25 watt single chip lamp with a heat sink very close to the active region is described.

A portable reading light has a telescoping arm that is slidable within a housing, the arm having a light source at the end thereof which has one or more light emitting diodes which provide bright light, low power consumption and durability. The light emitting diodes preferably are located in an articulatable light support and disposed adjacent to a focusing lens to better direct and shape the light onto a surface. The arm is mounted to a base assembly slidable within the housing and being telescopically expandable for stabilizing the arm when set for use.

Control systems and methods for independent control of power systems, particularly lighting network branches, and separate control of individual branch components. Multi-branch systems comprise independently controllable branches that inter-communicate via PLC communications. In each branch, components such as ballasts, local control units, sensors, actuators, and repeaters, may exchange commands and queries independently of a branch remote control unit (BRCU). Alternatively, a BRCU may manage or arbitrate communications, or interact with other BRCUs, other control units and external management systems. Ballasts include a multi-channel ballast that enables close-loop control of individual fixtures, or of individual dimmable or non-dimmable lamps within a fixture. The close-loop control is facilitated by sampling circuits / sensors co-located with each controlled fixture or lamp. All controllers are preferably implemented using an integrated digital controller. The PLC communication is preferably carried out by a direct spread spectrum method that eliminates side lobes from a cross-correlation function, using an anti-collision protocol.

Programmable occupancy sensors that control the on / off operation of a fluorescent lamp automatically determine loss of lamp life as the lamp is used. The programmable occupancy sensors can provide lamp life status and can automatically alert a user when a lamp is nearing its end of life and should be replaced. The occupancy sensors are also programmable to automatically maximize lamp life and energy savings by selecting an optimal time delay from among a number of selectable time delays at which to operate the sensor. The selection is based on an occupancy pattern sensed by the sensor over a given period of time. The optimal time delay, which prevents the lamp from turning off immediately after last sensing occupancy, extends lamp life by limiting the number of lamp off / on transitions, which shortens lamp life, in view of overall energy usage and lamp usage.

A LCD backlight inverter including: a dimming control unit comparing a level of a triangle wave with a level of a dimming control signal and controlling a dimming control current to be supplied or interrupted according to a comparison result; an error amplification unit having an input end to which a detection voltage corresponding to the dimming control current and a current flowing through a lamp are inputted, comparing the detection voltage with a predetermined reference voltage, and outputting an error voltage corresponding to a difference via an output end thereof, the output end working as a ground when the dimming control current is not inputted; and a time constant circuit unit comprising a resistor connected between the output end of the error amplification unit and a voltage source and a capacitor connected between the output end of the error amplification unit and a ground.

A display apparatus having a control unit which controls the light source temperature so that the temperature remains within a predetermined temperature range, a light modulation device for displaying images by receiving light emitted from the light source, and modulating the light according to the image data, and a light source controlling unit which adjusts the amount of light that enters the light modulation device, by controlling electrical power fed to the light source, according to the brightness data. Even if a contrast ratio is improved by changing the amount of light of an HID lamp, a passive optical modulation type display apparatus can be provided without reducing the lifetime of the light source lamp.

An electronic lamp control system for life time extension of a DC high intensity discharge lamp has a light sensor (130) for sensing an output of a lamp (31), a power supply (110) for the lamp (31), and a controller (20) for controlling the power supply (110). The controller (20) has a high pass filter (20c) for compensating for a leading edge of a detected change in lamp power output caused by each arc displacement. Lamp life is extended since damage to the lamp electrodes by the arc displacements is reduced. The system can have multiple lamps for the same illumination area, or multiple channels for illuminating different areas, coupled to provide uniform illumination. The controller (20) can compare a sensed level to a reference, to output a level control signal, then add a correction signal from the high pass filter to the level control signal.