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US 12,648,065 B2Granted
Method for controlling a pixelated light source
AssigneeValeo Vision
InventorSidahmed Beddar
Life of this patent
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Abstract
The invention relates to a method for controlling a pixelated light source for a motor vehicle. The method makes it possible to prevent thermal runaway and premature ageing of the elementary pixels of the source independently of the projected light levels. By dynamically adapting the electric current intensities at the elementary light sources, the control method provides protection for the semiconductor junctions of the pixels of the pixelated light source in order to increase their lifespan and avoid visible defects in a beam projected onto the road due to thermal runaway or premature ageing of the semiconductor junctions.
Claims9
A method for controlling a pixelated light source for a motor vehicle comprising:
- a plurality of elementary light sources with an electroluminescent semiconductor element, including:
- i. controlling, through a control unit the pixelated light source so as to project a light beam corresponding to image data through driving each elementary light source with a control signal that determines a first average intensity of an electric current flowing through each elementary light source;
- ii. obtaining a temperature profile of the pixelated light source by a plurality of temperature sensors arranged at predetermined locations;
- iii. estimating a position of a hot spot of the pixelated light source based on the image data and of an obtained temperature profile by the control unit;
- iv. estimating a temperature value of the hot spot based on an obtained temperature profile and on an estimated position of the hot spot relative to the predetermined locations of the plurality of temperature sensors by the control unit;
- v. modifying a command of the control signal delivered to the pixelated light source by a means of the control unit such that at least one group of the elementary light sources that include the elementary light source located at the estimated position of the hot spot is crossed through by a current of a second average intensity that is lower than the first average intensity, if an estimated temperature value is greater than a predetermined threshold temperature value;
- wherein the estimated position of the hot spot includes searching for the obtained temperature profile among a plurality of temperature profiles pre-recorded in a memory element;
- and
- wherein each temperature profile is associated with a particular image data and with a hot spot position associated with each data of the temperature profile associated with the particular image data.
6 more elements
A light-emitting assembly for a motor vehicle, comprising:
- a pixelated light source that applies a plurality of elementary light sources that are electroluminescent-semiconductor-component-based, wherein the pixelated light source is intended to be voltage-controlled such that a command determining a first average amplitude of a current passing through each elementary light source includes a first voltage level;
- a plurality of temperature sensors configured to deliver a temperature profile of the pixelated light source when projecting an image data;
- and
- a control unit, wherein the control unit is configured to control the pixelated light source depending on an estimated temperature value of a hot spot of the pixelated light source, which depends on an estimated position of the hot spot and on the image data;
- wherein the control unit is configured to:
- i. control the pixelated light source so as to project a light beam corresponding to image data, by driving each elementary light source with a control signal that determines the first average amplitude of the current passing through each elementary light source;
- ii. obtain a temperature profile of the pixelated light source;
- iii. compute the estimated position of the hot spot of the pixelated light source on the basis of the image data and of an obtained temperature profile;
- iv. compute the estimated temperature value of the hot spot depending on the obtained temperature profile and on the estimated position with respect to predetermined locations of the plurality of temperature sensors;
- and
- v. modify a command delivered to the pixelated light source so that at least one group of the plurality of elementary light sources includes a particular elementary light source that is located at the estimated position of the hot spot passing through by a current of a second average amplitude that is lower than the first average amplitude, if the estimated temperature value is higher than a predetermined threshold temperature value;
- wherein the estimated position of the hot spot includes searching for the temperature profile obtained from among a plurality of temperature profiles pre-recorded in a memory element;
- and
- wherein each temperature profile is associated with a particular image data and with a hot spot position associated with each data of the temperature profile associated with the particular image data.
11 more elements
Dependencies are inferred from the claim text.