Ketra, Inc.

National Instruments Corporation

Joseph Albert Savage

David J Knapp

Horace C Ho

Ryan Matthew Bocock

Jason E Lewis

Jivan James Luu

John Robert Breyer

Brian M Johnson

David W Fuller, Iii

John David Stanhope

Gregory Clark Richardson

An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for calibrating the illumination device is provided herein. According to one embodiment, the method may include subjecting a first LED to a first ambient temperature, measuring a forward voltage developed across the first LED upon applying a relatively small drive current to the first LED, detecting at least a first, a second and a third luminous flux output from the first LED upon successively applying at least a first, a second and a third drive current to the first LED, and storing results of the measuring and detecting steps within the illumination device to calibrate the first LED at the first ambient temperature. In some embodiments, the first LED may be subjected to a second ambient temperature, which is different from the first ambient temperature, and the method may repeat the steps of measuring, detecting and storing to calibrate the first LED at the second ambient temperature.

Illumination device and temperature calibration method

An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for controlling the illumination device while avoiding flicker in the LED output is provided herein. According to one embodiment, the method may include driving the plurality of LEDs substantially continuously with drive currents configured to produce illumination, periodically turning the plurality of LEDs off for short durations of time during a first period to take measurements or communicate optical data, and increasing the drive currents supplied to the plurality of LEDs by a small amount when the LEDs are on during the first period to compensate for lack of illumination when the LEDs are periodically turned off during the first period.

Illumination device and method for avoiding flicker

An illumination device and methods are provided herein for avoiding over-current and over-power conditions in one or more power converters included within the illumination device. The illumination device may include at least a plurality of light emitting diode (LED) chains, a driver circuit, at least one power converter, and a control circuit. In some embodiments, the control circuit may be generally configured for determining a maximum safe current level and/or a maximum safe power level attributed to the power converter(s) at a present operating temperature, and for adjusting respective drive currents supplied to the plurality of LED chains by the driver circuit, so as not to exceed the maximum safe current level or the maximum safe power level at the present operating temperature. In some embodiments, a temperature sensor may be included within the illumination device for measuring the operating temperature presently associated with the power converter(s).

Illumination device and method for avoiding an over-power or over-current condition in a power converter

An illumination device and method is provided herein for controlling individual light emitting diodes (LEDs) in an LED illumination device, so that a desired luminous flux and a desired chromaticity of the device can be maintained over changes in drive current and temperature. According to one embodiment, the illumination device comprises a plurality of emission LEDs, a storage medium, an LED driver and receiver circuit and a control circuit. The storage medium may store a table of calibration values correlating forward voltage and drive current to chromaticity and luminous flux at a plurality of temperatures for each of the plurality of emission LEDs. The LED driver and receiver circuit may apply respective drive currents to the emission LEDs to produce substantially continuous illumination, and may periodically turn the emission LEDs off to measure operating forward voltages that develop across each emission LED. The control circuit may determine whether a target luminance setting or a target chromaticity setting for the illumination device has changed, and if so, may determine new respective drive currents needed to achieve the target luminance setting and the target chromaticity setting using the operating forward voltages measured across each emission LED, the table of calibration values and one or more interpolation techniques.

Illumination device and method for controlling an illumination device over changes in drive current and temperature

An illumination device and methods are provided herein for avoiding over-current and over-power conditions in one or more power converters included within the illumination device. The illumination device may generally include a plurality of light emitting diode (LED) chains, a driver circuit, at least one power converter, and a control circuit. The LED chains may produce illumination for the illumination device at a chromaticity consistent with a chromaticity setting. The power converter(s) may be coupled for powering the LED chains, and may each comprise a maximum safe current level or a maximum safe power level, which varies with temperature. The control circuit may be configured for determining a maximum lumens value that can be safely produced by all LED chains at a predetermined safe temperature to achieve the chromaticity setting without exceeding the maximum safe current level or the maximum safe power level of the power converter(s) at the predetermined safe temperature.

Illumination device and method for determining a maximum lumens that can be safely produced by the illumination device to achieve a target chromaticity

An illumination device and methods are provided herein for avoiding over-current and over-power conditions in one or more power converters included within the illumination device. The illumination device may generally include a plurality of light emitting diode (LED) chains, a driver circuit, at least one power converter, a temperature sensor and a control circuit. The LED chains may produce illumination for the illumination device at a chromaticity consistent with a chromaticity setting. The power converter(s) may be coupled for powering the LED chains, and may each comprise a maximum safe current level or a maximum safe power level, which varies with temperature. The temperature sensor may be coupled for measuring a present temperature associated with the power converters. The control circuit may be configured for determining a target lumens value that can be safely produced by all LED chains at the present temperature to achieve the chromaticity setting without exceeding the maximum safe current level or the maximum safe power level associated with the power converters at the present temperature.

Illumination device and method for determining a target lumens that can be safely produced by an illumination device at a present temperature

An illumination device comprising a plurality of light emitting diodes (LEDs) and a method for controlling the illumination device, so as to maintain a desired luminous flux and/or a desired color point of the device over variations in temperature and process, is provided herein. According to one embodiment, the method may include measuring a forward voltage developed across a first LED of the illumination device upon applying a first drive current to the first LED, determining a drive current needed to achieve a desired luminous flux from the first LED using the measured forward voltage, a table of stored calibration values correlating forward voltage and drive current to luminous flux at a plurality of different temperatures, and one or more interpolation techniques, and driving the first LED with the determined drive current to produce illumination having the desired luminous flux. The steps of measuring, determining and driving may be performed for each of the plurality of LEDs.

Illumination device and temperature compensation method

System and method for using a graphical user interface (GUI) to generate a measurement task specification (MTS) for performing a measurement task. The measurement task includes measurement and/or signal generation. A measurement task specifier presents a GUI which guides a user in specifying the measurement task. The GUI presents a plurality of GUI elements, e.g., panels, for specifying a plurality of parameters for the measurement task, including measurement type, devices, channels, timing, and/or triggering. The GUI receives user input indicating values for the parameters, and may provide default values for at least some of the parameters. The GUI stores the parameter values in a memory, analyzes the parameter values, and generates the MTS in response to the analyzing. The MTS is then useable to produce a program which implements the measurement task. The specifier may programmatically generate the program, e.g., a graphical program, which is executable to perform the task.

Graphical user interface for easily configuring measurement applications

Measurement system graphical user interface for easily configuring measurement applications

A system and method for deploying a hardware configuration with a computer program. The program may perform an instrumentation, measurement/control, industrial automation, or machine vision function, or other type of function utilizing hardware devices, and the behavior of the program may depend on various aspects of the hardware configuration of the computer system. An installation bundle that includes configuration information related to the hardware devices with which the program interacts may be automatically created and used to deploy the program on a new computer system. The installation bundle may include program instructions operable to install the program on the new computer system and automatically modify the hardware configuration of the new computer system so that the program will execute correctly.

Growing community of inventors

Cedar Park, TX, United States of America

Joseph Albert Savage