EP3716733A1

EP3716733A1 - Electronic assembly and automotive lighting device

Info

Publication number: EP3716733A1
Application number: EP19382215.2A
Authority: EP
Inventors: Miguel Angel CANTUDO; Manuel CALMAESTRA; Miguel-Angel Pena
Original assignee: Valeo Iluminacion SA
Current assignee: Valeo Iluminacion SA
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-09-30

Abstract

The invention is referred to an electronic assembly (1) for an automotive lighting device (10). This electronic assembly (1) comprises a single power input (2), a single communication input (3) and a main driver element (4), which comprises driver inputs (40) arranged in direct bi-directional communication with the communication input and further comprising driver discrete outputs (41). The electronic assembly (1) further comprises a first group of light sources (7), electrically fed by the power input (2) and a first power unit (21) arranged between one driver discrete output (41) and the first group of light sources (7). The main driver element (4) comprises a hardware finite-state machine (43) configured to provide a bi-directional communication between the communication input (3) and the first power unit (21).

Description

TECHNICAL FIELD

This invention belongs to the field of lighting devices installed in automotive vehicles, and more specifically to the electronic assemblies used in these automotive lighting devices.

STATE OF THE ART

Lighting devices installed in automotive vehicles usually comprise light sources mounted on a printed circuit board (PCB). These light sources are usually controlled to be selectively activated, so that different presentations may be achieved, depending on the function required by the user.
This control has been traditionally made by means of micro-controllers (uC), such as in document US 2005/212459 A1 , which are connected to each light source and performs a selective control so that light sources are selectively activated or deactivated by the microcontroller in order to achieve the required function.
The use of micro-controllers in lighting devices is therefore increasing, because these dynamic functionalities are being demanded by the main automotive manufacturers. However, these micro-controllers are expensive, and need to be programmed.
A different way of achieving these dynamic functions is therefore sought.

DESCRIPTION OF THE INVENTION

The invention provides an alternative solution for improving the aforementioned problem by an electronic assembly according to claim 1 and an automotive lighting device according to claim 8. Preferred embodiments of the invention are defined in dependent claims.
In an inventive aspect, the invention provides an electronic assembly for an automotive lighting device, the electronic assembly comprising

a single power input;
a single communication input, intended to provide bi-directional communication with a control centre;
a main driver element, comprising driver inputs arranged in direct bi-directional communication with the communication input and further comprising driver discrete outputs;
a first group of light sources, electrically fed by the power input,
a first power unit arranged between one driver discrete output and the first group of light sources,

A power unit is defined as any unit capable of drive electric loads at a constant current. In particular embodiments, this element may be, e. g., a linear driver or a DC/DC converter.
This electronic assembly may advantageously be used in an automotive lighting device without any software programming. Hence, there is no need of updating or checking a software, and there is no need for some auxiliary elements, such as a transceiver and adapters, which were present in previous embodiments with micro-controllers. Further, since a whole group of light sources are controlled by a single output of the main driver element, more complex architectures are allowed.
In some particular embodiments, the electronic assembly further comprises a second group of light sources electrically fed by the power input, wherein the main driver element further comprises driver low current outputs and wherein the second group of light sources are directly connected to driver low current outputs.
This main driver may also comprise traditional low current outputs for a direct control of light sources which do not require an intermediate power step device.
In some particular embodiments, the electronic assembly further comprises a third group of light sources electrically fed by the power input and a second power unit arranged between one driver discrete output and the third group of light sources.
The fact that a group of light sources may be managed with an output of the main driver element causes that
In some particular embodiments, the first power unit is a linear driver or a DC/DC converter.
These elements are useful for managing the activation of high power light sources, which cannot be managed directly by the main driver element.
In some particular embodiments, the main driver element is arranged as a current sink, wherein the light sources are electrically arranged between the power input and the main driver element.
In some particular embodiments, the main driver element further comprises a BUS configuration memory and a measure and diagnosis units, and wherein

the hardware finite-state machine controls the driver outputs
the BUS configuration memory receives data directly from the communication input
the memory and diagnosis unit is arranged to receive data from the driver outputs and transmit them to the hardware finite-state machine.

This particular arrangement of the main driver element allows a bi-directional communication with the control centre of the vehicle without any software programmed element.
In some particular embodiments, the light sources are solid-state light sources, such as light emitting diodes (LEDs).
The term "solid state" refers to light emitted by solid-state electroluminescence, which uses semiconductors to convert electricity into light. Compared to incandescent lighting, solid state lighting creates visible light with reduced heat generation and less energy dissipation. The typically small mass of a solid-state electronic lighting device provides for greater resistance to shock and vibration compared to brittle glass tubes/bulbs and long, thin filament wires. They also eliminate filament evaporation, potentially increasing the life span of the illumination device. Some examples of these types of lighting comprise semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma or gas.
In a second inventive aspect, the invention provides a lighting device comprising an electronic assembly according to the first inventive aspect.
This lighting device is particularly useful in automotive applications, for lighting functionalities where a coordinated response is required, but may be obtained without the use of an expensive programmed controller.
In some particular embodiments, the lighting device further comprises a first optical element arranged to receive light from the plurality of light sources and to shape the light into a light pattern projected outside the lighting device.
An optical element is an element that has some optical properties to receive a light beam and emit it in a certain direction and/or shape, as a person skilled in automotive lighting would construe without any additional burden.
In some particular embodiments, the optical element is at least one of a light guide, a lens, a reflector or a collimator.
These optical elements are useful to manage the light produced by the plurality of light sources and provide uniform output.
In some particular embodiments, the lighting device is a a turning indicator, a cornering light, a fixed bending light or a daytime running lamp.
These lighting functionalities are typical to use a group of light sources to provide the coordinated response.

BRIEF DESCRIPTION OF THE DRAWINGS

To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be carried out. The drawings comprise the following figures:

Figure 1 shows an electronic assembly according to the invention.
Figure 2 shows a detailed scheme of an element of an electronic assembly according to the invention.
Figure 3 shows a lighting device comprising an electronic assembly according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.
Accordingly, while embodiment can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.
Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.
In this text, the term "comprises" and its derivations (such as "comprising", etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.
Figure 1 shows a first schematic view of an electronic assembly 1 according to the invention. This electronic assembly 1 comprises

a single power input 2;
a single communication input 3, intended to provide bi-directional communication with a control centre;
a main driver element 4; and
four groups of LEDs 5, 6, 7, 8, electrically fed by the power input 2.

The main driver element 4 comprises a driver input 40 arranged in direct bi-directional communication with the communication input 3 and further comprises two types of driver outputs: driver discrete outputs 41 and driver low current outputs 42.
Low current outputs 42 are arranged to feed two groups of low current LEDs 5, 6. Due to the fact that these group of LEDs work with low current, they may be directly managed by the main driver element 4, without the interposition of any intermediate power stage.
Driver discrete outputs 41 are arranged to feed two groups of high power LEDs 7, 8. However, since the main driver element 4 is not able to provide a high amount of power, intermediate power units 21, 22 are arranged between each driver discrete output 41 and each group of high power LEDs 7, 8.
In this particular example, the first intermediate power unit 21 is a linear driver and the second intermediate power unit 22 is a DC/DC converter.
As may be seen in this figure, the main driver element 4 is arranged as a current sink, because the groups of LEDs 5, 6, 7, 8 are electrically arranged between the power input 2 and the main driver element 4.
Figure 2 shows a more detailed scheme of the main driver element 4 of figure 1. This main driver 4 comprises the following

driver discrete outputs 41;
driver low current outputs 42;
a hardware finite-state machine 43 with a BUS configuration memory 44;
a measure and diagnosis unit 45;

The hardware finite-state machine 43 controls the driver outputs 41, 42, thus controlling the activation and deactivation of the groups of LEDs. In turn, the BUS configuration memory 44 receives data directly from the communication input 3, so that the hardware finite state machine may act according to the information received.
Furthermore, the memory and diagnosis unit 45 is arranged to receive data from the driver outputs 41, 42 and transmit them to the hardware finite-state machine 43, so that this information is suitably transmitted to the communication input 3 and then to the control centre.
Figure 3 shows a lighting device 10 comprising an electronic assembly 1 according to the invention. This lighting device is a headlamp and is installed in an automotive vehicle 100.
This lighting device comprises a projecting lens 9 which receives the light of the plurality of LEDs (not seen) and shape it into a light pattern projected outside the lighting device 10.

Claims

Electronic assembly (1) for an automotive lighting device (10), the electronic assembly (1) comprising
a single power input (2);

a single communication input (3), intended to provide bi-directional communication with a control centre;

a main driver element (4), comprising driver inputs (40) arranged in direct bi-directional communication with the communication input and further comprising driver discrete outputs (41);

a first group of light sources (7), electrically fed by the power input (2),

a first power unit (21) arranged between one driver discrete output (41) and the first group of light sources (7),
wherein the main driver element (4) comprises a hardware finite-state machine (43) configured to provide a bi-directional communication between the communication input (3) and the first power unit (21).
Electronic assembly (1) according to claim 1, further comprising a second group of light sources (5) electrically fed by the power input (2), wherein the main driver element (4) further comprises driver low current outputs (42) and wherein the second group of light sources (5) are directly connected to driver low current outputs (42).
Electronic assembly (1) according to any of the preceding claims, further comprising a third group of light sources (8) electrically fed by the power input (2) and a second power unit (22) arranged between one driver discrete output (41) and the third group of light sources (8).
Electronic assembly (1) according to any of the preceding claims, wherein the first power unit (21) is a linear driver or a DC/DC converter.
Electronic assembly (1) according to any of the preceding claims, wherein the main driver element is arranged as a current sink, wherein the light sources are electrically arranged between the power input (2) and the main driver element (4).
Electronic assembly (1) according to any of the preceding claims, wherein the main driver element (4) further comprises a BUS configuration memory (44) and a measure and diagnosis units (45), and wherein
the hardware finite-state machine (43) controls the driver outputs (41, 42);

the BUS configuration memory (44) receives data directly from the communication input (3);

the memory and diagnosis unit (45) is arranged to receive data from the driver outputs (41, 42) and transmit them to the hardware finite-state machine (43).
Electronic assembly (1) according to any of the preceding claims, wherein the light sources are solid-state light sources, such as light emitting diodes or LEDs.
Automotive lighting device (10) comprising an electronic assembly (1) according to any of the preceding claims.
Automotive lighting device (10) according to claim 8, further comprising a first optical element (9) arranged to receive light from the plurality of light sources (5) and to shape the light into a light pattern projected outside the lighting device.
Automotive lighting device (10) according to claim 9, wherein the optical element (9) is at least one of a lens, a light guide, a reflector or a collimator.
Automotive lighting device (10) according to any of claims 8 to 10, the lighting device (10) being a headlamp or a rear lamp.