Leotek Electronics Corporation

Chen-Ho Wu

Chin-Wang Tu

Shih Chang Wang

Chinmau James Hwang

Shih-Chang Wang

Yi-Kai Cheng

Han-Jen Chuang

Shih Kuei Wang

Ching Yuan Chung

Shu-Chun Chang

Bing-Yu Wu

A traffic signal light device that includes a spread window, a Fresnel lens, and an LED module for emitting light. The light emitted by the LED module passes through the Fresnel lens and to the spread window. The LED module is disposed at a position that is offset from an axis of the spread window that passes through a center of, and is perpendicular to, the spread window. The Fresnel lens can have a saw-toothed pattern of teeth formed as concentric circles on one surface of the Fresnel lens sharing a common center, where the size or height of the teeth vary. The spread window can have a plurality of protruding cells of varying size on a surface of the spread window.

Traffic signal light device

A method and apparatus for adjusting the drive signal of an LED luminaire is provided and includes an LED light source assembly, an ambient sensor circuit, a comparator circuit, and a driver circuit. The ambient sensor circuit provides an ambient signal to the LED light source assembly, which is a function of the ambient (such as temperature, humidity or air visibility) proximate to the LED light source assembly. The comparator circuit provides a bidirectional ambient adjustment signal to the driver circuit, which is a function of the ambient signal and a reference signal. And the driver circuit provides an adjustable drive signal to the LED light source assembly, which is a function of the bidirectional ambient adjustment signal.

LED luminaire with improved life and operation management

A method and device for replacing a fluorescent tube lamp with an LED lamp. The LED lamp includes an elongated electrical assembly having ends terminating in first and second electrical connectors, and a plurality of LEDs mounted to the elongated electrical assembly. Mounting adaptors connect with the first and second electrical connectors, and have protruding pins to connect with conventional lamp socket connectors. The mounting adaptors have rotating connectors for connecting with the first and second electrical connectors of the LED lamp, so that the LED lamp orientation can be rotated after the LED lamp is fully mounted to the lamp socket connectors.

Retrofitting of fluorescent tubes with light-emitting diode (LED) modules for various signs and lighting applications

A high power LED lamp and method for retrofitting conventional traffic signal lamps. The LED lamp includes a housing, a power supply disposed in the housing, a plurality of LEDs mounted to a substantially planar mounting surface in the housing and electrically connected to the power supply for producing diverging light, and a threaded electrical connector extending from the housing. The method includes replacing a convention incandescent light bulb with the LED lamp, and installing a Fresnel lens inside the traffic signal lamp that collimates and just fills and illuminates the outer lens of the traffic signal lamp.

LED tube lights with clear bottom base

A method and apparatus for installing an LED lamp module into a light such as a traffic signal light. The LED lamp module includes a plurality of LEDs for producing light. The traffic signal light includes a housing, a door assembly removably or movably attached to the housing and having an aperture for passing the light, and a securing bracket having a first end secured to the door assembly and a second end secured to the LED lamp module, for maintaining an alignment between the door assembly and the LED lamp module.

Traffic signal lamp assembly and method of replacing same

An LED lamp module for use with a threaded electrical socket connector is provided, which includes an LED light engine with a first electrical connector, a second electrical connector having a first end electrically engagable with the first electrical connector and a second end having a threaded outer surface compatible with a threaded electrical socket connector. The LED lamp module further comprises a sleeve surrounding the first electrical connector and the first end such that the sleeve allows for relative rotation between the first electrical connector and the first end in a loosened state, and restricts relative rotation between the first electrical connector and the first end in a tightened state. A method for installing a retrofit LED lamp module in a housing which physically restricts full rotation of an LED light engine is also provided. The method includes connecting a first electrical connector to a second electrical connector, wherein the first electrical connector is attached to an LED light engine, and wherein the second electrical connector further comprises a first end electrically engagable with the first electrical connector, and a second end having a threaded outer surface compatible with a threaded electrical socket connector. The method further comprises tightening this connection via a sleeve surrounding the first electrical connector and the first end such that the sleeve allows for relative rotation between the first electrical connector and the first end in a loosened state, and restricts relative rotation between the first electrical connector and the first end in a tightened state.

Light emitting diode (LED) based street light and other lighting applications

An illuminated sign having front, back and side surfaces. A plurality of first cavities are formed into the back surface of the sign. A plurality of light emitting modules are disposed in the plurality of first cavities. The modules each include a light emitting diode having an emission axis and for producing at least some light output generally parallel to the emission axis, an optical device disposed adjacent the light source having a reflective surface for reflecting the light output in directions that are generally perpendicular to the emission axis, and a guide element disposed adjacent the optical device for coupling the reflected light output into the interior of the sign. The guide element includes a second cavity formed therein in which the optical device is disposed. The front surface is illuminated by the coupled light output from the light emitting modules by reflection and/or diffusion inside the sign.

Internally illuminated light panel with LED modules having light redirecting devices

A linear array of light emitting diodes with a lens stripe for evenly illuminating signs, which includes a linear array of light emitting diodes (LEDs) for producing a light output, and an elongated lens stripe. The linear array of LEDs includes an elongated mounting member and a plurality of LEDs mounted along the length of the mounting member. The elongated lens stripe is attached to the linear array of LEDs, and includes a reflector portion and a lens portion. The reflector portion has two elongated and opposing side walls that form an elongated channel. The side walls are light reflective. The LEDs are disposed inside the channel. The channel side walls reflect the light output from the LEDs toward the elongated open end of the channel. The lens portion has an elongated lens disposed along the open end of the channel for focusing the light output from the LEDs. The focused light output enters the side edge of a display board type sign for even illumination, or is projected onto the opaque front surface of a sign for even illumination.

Light emitting diode linear array with lens stripe for illuminated signs

A circuit for driving a plurality of light emitting diodes (LEDs) that includes a power supply and a voltage divide circuit utilizing positive and negative temperature coefficient thermistors to boost the drive voltage to the LEDs as the ambient temperature deviates from room temperature, which compensates for increased electrical resistance of the LEDs at low temperatures and decreased LED light output efficiency at high temperatures. The circuit also provides a signal voltage to indicate the drive current through the LEDs, and includes a transistor to shut down the power supply when the signal voltage drops below a predetermined level (i.e. the number of burned out LEDs exceeds a predetermined number). A compensation circuit utilizes a thermistor to boost the signal voltage as the ambient temperature drops to compensate for the characteristic turn-on voltage of the transistor that increases as the temperature of the transistor drops.

Growing community of inventors

Los Altos Hills, CA, United States of America

Chen-Ho Wu