Voltage-controlled matrix light source with diagnostic circuit for a motor vehicle
AssigneeValeo Vision
InventorsSamuel Daroussin, Olivier Valorge, Marjaneh Kazemi
Life of this patent
Estimating the term…
Abstract
A matrix light source intended to be supplied with a voltage and having a plurality of electroluminescent semiconductor element-based elementary light sources and a common substrate in contact with an integrated circuit. The integrated circuit includes, for each elementary light source, a switching device for selectively connecting it to a voltage source on the basis of a first control signal. The substrate includes, for at least one of the elementary light sources, an open-circuit fault detection circuit for detecting an open-circuit fault with the elementary light source.
Claims18
A matrix light source intended to be supplied with a voltage and
- comprising an integrated circuit and a matrix array of electroluminescent semiconductor element-based elementary light sources, wherein the integrated circuit is in contact with the matrix array and comprises, for each elementary light source, a switching device for selectively connecting a respective elementary light source to a voltage source on the basis of a first control signal,
- wherein the integrated circuit comprises, for at least one of the elementary light sources, an open-circuit fault detection circuit for detecting an open-circuit fault with the elementary light source,
- wherein said open-circuit fault detection circuit comprises a load connected in parallel with the switching device, such that an electric current of non-negligible intensity flows through the load if the matrix source is supplied with electricity, unless the elementary light source has an open-circuit fault.
A method for detecting an open-circuit fault with a matrix light source, wherein the method comprises the following steps:
- supplying a voltage to the matrix light source, the matrix light source comprising an integrated circuit and a matrix array of electroluminescent semiconductor element-based elementary light sources, wherein the integrated circuit is in contact with the matrix array and comprises, for each elementary light source, a switching device for selectively connecting a respective elementary light source to a voltage source on the basis of a first control signal;
- by way of a control device for the matrix light source, generating at least a first signal for controlling the state of the switching device so as to selectively connect at least one elementary light source of the matrix light source to the voltage source;
- when said elementary light source is not connected to the voltage source by way of its switching device, comparing the voltage drop across the terminals of a load connected in parallel with the switching device to a predetermined threshold voltage;
- and
- detecting the presence of an open-circuit fault with said elementary light source on the basis of the result of this comparison, wherein an electric current of non-negligible intensity flows through the load if the matrix source is supplied with electricity, unless the elementary light source has an open-circuit fault.
Dependencies are inferred from the claim text.