Abstract: The present invention relates to a calibration circuit, computer program product, and method of calibrating a junction temperature measurement of a semiconductor element, wherein respective forward voltages at junctions of the semiconductor element and a reference temperature sensor are measured, and an absolute ambient temperature is determined by using the reference temperature sensor, and the junction temperature of the semiconductor element is predicted based on the absolute ambient temperature and the measured forward voltages.

Abstract: An active thermal management device and method, in which a phase change material unit, comprising at least one phase change material arranged in series or parallel, is connectable to a source of thermal energy, such as LEDs at a first operating condition. Thermal energy from the source of thermal energy is stored in the phase change material unit. The phase change material unit is connectable to a sink of thermal energy, such as second LEDs at a second operating condition. The thermal energy stored in the phase change material unit may be re-used. The first operating condition can include a 15V supply voltage, and the second operating condition can include either no supply voltage, or a lower 9V supply voltage of 9V, such that heat from the first LEDs, which may be over-temperature, can pre-heat the second LEDs, improving thermal and optical matching.

Abstract: A driver circuit (10) for a light emitting diode comprises a first driver circuit (32, 32?, 32?) for generating a first current output for driving the light emitting diode, wherein the first driver circuit has a control switch for interrupting the supply of the first current output. A second driver circuit (50) is for generating a second current output for driving the light emitting diode, and the second driver circuit also has a control switch for interrupting the supply of the second current output. The overall output of the driver circuit comprises a pulse width modulated output current which alternates between a high current (Ihigh) generated by the first driver circuit and a low current (Ilow) generated by the second driver circuit. By providing separate driver circuits for two different current requirements, the circuits can be optimised for each function. For example the high current value can comprise an LED operation current, and the low current value can comprise a non-zero measurement current.

Abstract: An optical analysis apparatus and method in which a detector provides two different signals, based on responses to incident light absorbed within the detector over different depths. These signals are processed to discriminate between incident light of two different frequencies and thereby determine the intensity of the light of one desired frequency.

Abstract: Apparatus for regulating the temperature of a light emitting diode (LED). The apparatus includes a heat sink, an LED mount, and an LED mounted on the LED mount. The LED mount is configured to change shape in response to a change in temperature. The change in shape alters the position of the LED relative to the heat sink, for adjusting heat transfer between the LED and the heat sink. The LED mount may include a laminated portion such as a bi-metallic strip.

Abstract: A lighting unit comprises a packaging substrate (10) formed from a semiconductor, a channel (12) formed in the substrate and a discrete light emitting diode arrangement (34) in the channel. A surface region of the channel comprises doped semiconductor layers (20, 24) which define a light sensor. The arrangement provides a light sensor (which can be used to determine colour and/or output flux) for a LED unit, with the light sensor embedded in substrate used for packaging. This provides a low cost integration process and provides good registration between the light sensor and the LED output.

Abstract: A display device comprises a substrate which carries an array of pixels. Each pixel comprises an array of apertures in the substrate, each aperture of the array having a maximum opening dimension less than the wavelength of the light to be transmitted through the aperture. The effective dielectric constant of the aperture and/or the dielectric constant of the substrate is varied, thereby to vary the light transmission characteristics of the pixel between transmission of at least one frequency in the visible spectrum and transmission of substantially no frequency in the visible spectrum.

Abstract: A lighting system for exterior lights of an automobile comprises a first lighting unit (10,12,14,16) primarily for outputting a first automotive light signal and a failure detection system (26) for detecting a failure of the first lighting unit (10,12,14,16). A second lighting unit is primarily for outputting a second automotive light signal. The second lighting unit comprises an LED light unit. A controller (30) is adapted to determine if there is failure of the first lighting unit, and if there is failure of the first lighting unit, to use the second lighting unit to generate the first automotive light signal. This is in response to an output request from the first lighting unit (10,12,14,16).

Abstract: A method is disclosed of controlling a LED, comprising driving the LED with a DC current for a first time, interrupting the DC current for a second time such that the first time and the second time sum to a period, determining at least one characteristic of the LED whilst the DC current is interrupted, and controlling the DC current during a subsequent period in dependence on the at least one characteristic. The invention thus benefits from the simplicity of DC operation. By operating at the LED in a DC mode, rather than say in a PWM mode, the requirement to be able to adjust the duty cycle is avoided. By including interruptions to the DC current, it is possible to utilise the LED itself to act as a sensor in order to determine a characteristic of the LED. The need for additional sensors is thereby avoided.

Abstract: The present invention relates to a calibration circuit, computer program product, and method of calibrating a junction temperature measurement of a semiconductor element, wherein respective forward voltages at junctions of the semiconductor element and a reference temperature sensor are measured, and an absolute ambient temperature is determined by using the reference temperature sensor, and the junction temperature of the semiconductor element is predicted based on the absolute ambient temperature and the measured forward voltages.

Abstract: A light sensor device comprises a substrate (10) having a well (12) defined in one surface. At least one light sensor (14) is formed at the base of the well (12), and an optical light guide (18) in the form of a transparent tunnel (18) within an opaque body (20) extends from a top surface of the device down a sloped side wall of the well (12) to the location of the light sensor (14).

Abstract: Apparatus for regulating the temperature of a light emitting diode (LED). The apparatus includes a heat sink, an LED mount, and an LED mounted on the LED mount. The LED mount is configured to change shape in response to a change in temperature. The change in shape alters the position of the LED relative to the heat sink, for adjusting heat transfer between the LED and the heat sink. The LED mount may include a laminated portion such as a bi-metallic strip.

Abstract: An apparatus comprising at least one measuring cell (10) is disclosed. The measuring cell comprises a first cavity (16 and a second cavity (18) perpendicular to the first cavity, the first cavity and the second cavity comprising an overlap at first respective ends and a reflective surface (20) at the opposite respective ends. A beam splitter (15) is located in the overlap and an electromagnetic radiation source (12) is arranged to project a beam of electromagnetic radiation onto the beam splitter (15) such that the beam is projected into each of the cavities. A phase detector (22) for detecting a phase difference between the respective electromagnetic radiation reflected by the first and second cavity (16; 18) is also provided. In addition, the apparatus has a fluid channel (26), at least a part of which runs parallel to the first cavity (16) such that the electromagnetic radiation projected into the first cavity extends into said part of the fluid channel.

Abstract: The present invention relates to a luminescent component (30) and a manufacturing method thereof. The luminescent component (30) comprises a first transparent carrier (18), a second transparent carrier (24), a substrate (10) sandwiched between said transparent carriers (18; 24), the substrate (10) comprising a conduit from the first transparent layer (18) to the second transparent carrier (24), the conduit being filled with a luminescent solution (20). This facilitates the use of colloidal solutions of quantum dots in such a luminescent component (30). Preferably, the substrate (10) is direct bonded to the transparent carriers (18, 24) using direct wafer bonding techniques.

Abstract: A method of determining the ageing characteristics of an LED comprises applying a current stress pulse to the LED. The LED is monitored to determine when the thermal heating induced by the current stress pulse has been dissipated to a desired level. The operational characteristics of the LED are then measured before applying the next stressing pulse. This method accelerates the effect of aging in a reproducible way and therefore is able to greatly reduce the time needed for a reliability test.

Abstract: A method of estimating the output light flux of a light emitting diode, comprises applying a drive current waveform to the LED over a period of time comprising a testing period. The forward voltage across the LED is monitored during the testing period, and the output light flux is estimated as a function of changes in the forward voltage.

Abstract: A method of manufacturing an I-MOS device includes forming a semiconductor layer (2) on a buried insulating layer (4). A gate structure (23) including a gate stack (14) is formed on the semiconductor layer, and used to (5) self align the formation of a source region (28) by implantation. Then, an etch step is used to selectively etch the gate structure (23) and this is followed by forming a drain region (36) by implantation. The method can precisely control the i-region length (38) between source region (28) and gate stack (14).

Abstract: A method of providing a dielectric material (18) having regions (18?, 18?) with a varying thickness in an IC manufacturing process is disclosed. The method comprises forming a plurality of patterns in respective regions (20?, 20?) of the dielectric material (18), each pattern increasing the susceptibility of the dielectric material (18) to a dielectric material removal step by a predefined amount and exposing the dielectric material (18) to the dielectric material removal step.

Abstract: A method of estimating the junction temperature of a light emitting diode comprises driving a forward bias current through the diode, the current comprising a square wave which toggles between high and low current values (Ihigh, llow), the high current value (lhigh) comprising an LED operation current, and the low current value (IIOW) comprising a non-zero measurement current. The forward bias voltage drop (Vf) is sampled and the forward bias voltage drop (Vflow) is determined at the measurement current (IIOW)—The temperature is derived from the determined forward bias voltage drop.

Abstract: The present invention relates to a manufacturing method of an integrated circuit (IC) comprising a substrate (10) comprising a pixelated element (12) and a light path (38) to the pixelated element (12). The IC comprises a first dielectric layer (14) covering the substrate (10) but not the pixilated element (12), a first metal layer (16) covering a part of the first dielectric layer (14), a second dielectric layer (18) covering a further part of first dielectric layer (14), a second metal layer (20) covering a part of the second dielectric layer (18) and extending over the pixelated element (12) and a part of the first metal layer (16), the first metal layer (16) and the second metal layer (20) forming an air-filled light path (38) to the pixelated element (12).