EP3606289A1

EP3606289A1 - Electronic device, method for controlling a lighting device and automotive lighting device

Info

Publication number: EP3606289A1
Application number: EP18382581.9A
Authority: EP
Inventors: Jose-Luis LOPEZ
Original assignee: Valeo Iluminacion SA
Current assignee: Valeo Iluminacion SA
Priority date: 2018-07-31
Filing date: 2018-07-31
Publication date: 2020-02-05
Anticipated expiration: 2038-07-31
Also published as: EP3606289B1

Abstract

The present invention refers to an electronic device (1) comprising a controlling unit (2, 3) configured to feed some light sources (6) when a lighting functionality is active and not to feed the light sources when the lighting function is inactive. This electronic device (1) also comprises a diagnosis unit (4) and a storage unit (5), the diagnosis unit (4) being adapted to sense a failure of any of the light sources (6) when the light function is active and to emit a failure alert intended to be received by the storage unit (5) if a failure is sensed in any of the light sources (6). The storage unit (5) is able to keep this failure status for a lapse of time even without being powered. The controlling unit (2, 3) is adapted to read the failure status stored in the storage unit (5) to control the lighting device (10), and is also adapted to feed the light sources in at least two different modes, the mode depending at least on the failure status read from the storage unit. This invention also provides a method for controlling a lighting device by such an electronic device (1) and an automotive lighting device comprising this electronic device (1).

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), which are connected to each light source and performs a selective control so that light sources are selectively activated or deactivated by the micro-controller in order to achieve the required function.
In the case of turning indicators, regulation now allows this functionality to be provided in running mode for every situation. Hence, there is no need to provide two different modes, static mode and running mode, for this functionality. However, when a failure occurs, the activation in running mode may require a complex actuation of the micro-controller, which must save the failure configuration. This configuration is difficult and expensive to store in the micro-controller non-volatile memory. This situation is particularly complex in the event of the turning indicator functionality, since the failure status must be detected when the functionality is activated, but not powered.
A different way of managing this situation is therefore sought.

DESCRIPTION OF THE INVENTION

An alternative solution for the aforementioned problem is provided by an electronic device according to claim 1, a method for controlling a lighting device according to claim 12 and an automotive lighting device according to claim 14. Particular embodiments of the invention are defined by dependent claims.
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.
In an inventive aspect, the invention provides an electronic device for controlling a lighting module of an automotive vehicle comprising light sources to perform a lighting function; wherein
the electronic device comprises a controlling unit configured to feed the light sources when the lighting function is active and not to feed the light sources when the lighting function is inactive
the electronic device comprises a diagnosis unit and a storage unit, the diagnosis unit being adapted to sense a failure of any of the light sources when the light function is active and to emit a failure alert intended to be received by the storage unit, either directly or by means of an element of the electronic device, if a failure is sensed in any of the light sources, the storage unit being able to keep this failure status for a lapse of time even without being powered;
the controlling unit is adapted to read the failure status stored in the storage unit to control the lighting device:
the controlling unit is adapted to feed the light sources in at least two different modes, the mode depending at least on the failure status read from the storage unit.
This system manages to keep the defect status of the failing light source even while the function is not powered, since this failure status is not stored in the controlling unit, but in a storage unit which is able to keep this status even without being powered. Since the turning indicator comprises phases when the light sources are not powered, this electronic device is particularly advantageous to provide and manage such information.
The storage unit may be connected to the diagnosis unit or connected to a different element, such as the controlling unit, which would receive the failure alert from the diagnosis unit and send it to the storage unit.
In some particular embodiments, the storage unit is a memory cell separated from the controlling unit.
A separated memory cell may be easily manufactured, replaced and adapted to current designs, since it is just a simple additional element which may be incorporated to current structures.
In some particular embodiments, the storage unit comprises a capacitor and at least one MOSFET, so that two consecutive writing operations are allowed with less than 200 ms between them.
These elements make the storage unit be able to admit two consecutive writing operations with a very low time interval between them. This is useful for current animated functionalities, where dynamic operations are very fast and require a quick response time. There is no need to use any on-chip data flash devices for micro-controllers, or external IC memory devices. Software development is not needed either.
In some particular embodiments, the storage unit comprises a capacitor configured to store the failure status, the capacitor being also configured to discharge if the storage unit does not receive any failure alert during a time interval comprised between 2 and 5 seconds.
Since the storage unit is able to store the failure status without being powered, storing the failure status on a capacitor provides a simple way of resetting the failure status once the lighting functionality has been turned off. Hence, an additional reset generator is not needed.
In some particular embodiments, the storage unit comprises a Zener diode configured to provide the failure status to the controlling unit.
This Zener diode is a simple solution to provide a "Y/N" status to the microcontroller. The voltage threshold may be regulated to choose the reset time value of the failure status.
In some particular embodiments, the storage unit comprises switching transistors and is configured to store the failure status by switching the switching transistors when the diagnosis unit provides a failure alert.
Transistor switching is a suitable way of activating the storing of this failure status in the storage unit, since it is very reliable and fast.
In some particular embodiments, the lighting function is a turning indicator. As has been indicated above, this electronic device is particularly suitable for a turning indicator functionality.
In some particular embodiments, the different modes comprise a first static mode, where all the light sources are activated and deactivated at the same time, and a second dynamic mode, where the light sources are sequentially activated.
Current regulations allow the activation of the turning indicator functionality in running mode in all cases. However, it is useful to keep the possibility of activating this functionality in the static mode or in different modes, since it may respond better in the event of a light source failure. When a failure occurs, known devices switch off the turning indicator during ON and OFF cycles instead of, for example, doing the running once up to reach the segment with the failure and then switch off the TI. This device allows this latter option, since it provides a simple and inexpensive way of storing the failure status during OFF cycle.
In some particular embodiments, the controlling unit comprises a micro-controller configured to generate a sequence pattern for the activation of the light sources.
The controlling unit may comprise a micro-controller, which is suitable for achieving complex animations, but this invention may be also applicable to other kind of non-programmable elements.
In some particular embodiments, the controlling unit is configured to receive the failure alert from the diagnosis unit and is configured to send the failure alert to the storage unit with instructions to store it or not.
In this case, the failure alert is sent from the diagnosis unit to the storage unit via the controlling unit, which is also configured to choose if this failure alert is to be stored or not. This controlling unit is advantageously used in this case for a further control of the alert management.
In some particular embodiments, the controlling unit further comprises at least one driver, configured to control the current intended to pass through each light source.
In some particular embodiments, the storage unit comprises means for storing at least two different failure status, each failure status being associated to one of the light sources.
These embodiments are particularly useful when the activation mode depends on which light source is failing.
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 method for controlling a lighting device comprising an electronic device according to any of the preceding claims, the method comprising the steps of
the controlling units activates the lighting functionality and control the light sources in a first standard mode;
the diagnosis unit checks a failure status of at least one of the light sources by means of the diagnosis unit;
in the event any of the light sources fails, the diagnosis unit sends a failure alert to the storage unit;
the storage unit stores a failure status; and
the controlling unit checks the failure status of the storage unit by means of the controlling unit;
the controlling unit controls the light sources according to the failure status read on the storage unit.
This method allows a fast and reliable management of light source failures, as has been indicated above.
In some particular embodiments, after the step of controlling the light sources according to the failure status the method cycles back to the step of checking a failure status by means of the diagnosis unit.
This cycling pattern is particularly advantageous for some lighting functionalities, such as turning indicator, where the functionality is provided in ON and OFF cycles.
In a third inventive aspect, the invention provides an automotive lighting device comprising an electronic device according to the first inventive aspect.
This lighting device is particularly useful in automotive applications, for lighting functionalities where a failure in one of the light sources may cause a significant loss of the performance.
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.

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 a first general scheme of an electronic device according to the invention.
Figure 2 shows the complete electronic structure of the storage unit of a particular embodiment of an electronic device 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.
Figure 1 shows a first general scheme of an electronic device 1 according to the invention. This electronic device 1 is suitable for controlling a lighting module of an automotive vehicle comprising light sources to perform a turning indicator function.
The electronic device 1 according to this embodiment comprises
a controlling unit comprising a micro-controller 2 and a driver 3;
a diagnosis unit 4;
a storage unit 5; and
a plurality of LED segments 6.
The micro-controller 2 is configured to create an animation pattern and to feed the light sources according to this animation pattern when the turning indicator functionality is active. The driver 3 is in turn configured to control the current intended to pass through each of the LED segments.
The diagnosis unit 4 is configured to sense a failure of any of the LED segments when the turning indicator functionality is active and to emit a failure alert intended to be received by the storage unit 5 if a failure is sensed in any of the LED segments. In this case, the failure alert is sent to the micro-controller 2 which stores it in the storage unit 5.
The storage unit 5 is able to keep this failure status for a lapse of time even without being powered, since this failure status is store in hardware elements which do not need to be powered to keep the failure status value.
The micro-controller 2 is adapted to read the failure status stored in the storage unit 5 to control the lighting device in a predetermined mode. This predetermined mode depends at least on the failure status read from the storage unit.
Figure 2 shows the complete electronic structure of the storage unit 5 of a particular embodiment of an electronic device according to the invention.
As has been previously described, the diagnosis unit 4 checks the performance of each LED segment 6 and sends a failure alert to the micro-controller 2. When a failure alert is received, the micro-controller emits a failure signal which enters the storage input 51.
This failure signal activates the switch assembly 52, which activates the capacitor 53, where the failure status is stored. This capacitor 53 is fed by the battery signal 54 so that it charges while the failure status is sent. Once the failure status stops, due to the deactivation of the functionality, the capacitor discharges in a time lapse which is around 5 seconds, so the failure status is reset once this time lapse has passed.
The switch assembly comprises a capacitor and MOSFET transistors, so that two consecutive writing operations are allowed with less than 200 ms between them.
The storage unit 5 further comprises a Zener diode 55 configured to provide the failure status to the micro-controller 2. In the event of a digital micro-controller, this Zener diode provides a digital output which is "positive" when the charge of the capacitor is higher than a predetermined threshold and is "negative" when it is below this value. In the event of an analogue controller, the Zener diode is used as a protection for this controller, since it limits the voltage of the capacitor 53.
In different embodiments, different circuit patterns are provided which ensure the same functionality for this storage unit.
The device described above would work in the following exemplary way.
First, the vehicle user activates the turning indicator functionality, and the micro-controller 2 creates an animation for the LED segments 6, according to the predetermined running mode.
The animation pattern is transmitted to the driver 3 which sets a predetermined current for each LED segment, which is sequentially activated according to the micro-controller pattern. As a consequence, this pattern comprises several animation stages: in a first stage, the first LED segment is activated and the remainder are kept deactivated; in a second stage, the second LED segment is activated and the remainder are kept deactivated, and so on.
After each one of the stages, the diagnosis unit checks if the corresponding LED segment has been correctly activated. In the event that any of the LED segments 6 is not correctly activated, the diagnosis unit 4 sends a failure alert to the storage unit 5.
When the storage unit 5 receives the failure alert, it changes the failure status, to alert the micro-controller 2 that there has been a failure in one of the LED segments 6. The micro-controller 2 reads the failure status of the storage unit 5 before each stage, so that, when the micro-controller 2 detects that there is a failure in one of the LED segments 6, it changes the activation mode from the animation pattern to a static mode, where all the LED segments 6 are activated at the same time. Each time the LED segments 6 are activated, the diagnosis unit 4 detects that one of the LED segments 6 is failing, so it sends the failure alert to the storage unit 5. Since the failure status is stored in a capacitor, this status would reset if the storage unit did not receive any updated information about the failure status of the LED segments from the diagnosis unit, since the capacitor would discharge if no further electric signal is received during the discharge time (which is usually comprised between 2 and 5 seconds). This reset also happens when the turning indicator functionality is turned off by the vehicle user.
Figure 3 shows a lighting device 10 comprising an electronic assembly 1 according to the invention. This lighting device 10 comprises a turning indicator functionality, which may be activated by the vehicle user.
In normal operation, the lighting device 10 is configured to activate the turning indicator functionality in a running mode, but in the event any of the LED segments 6 fails, the lighting device 10 will activate the turning indicator functionality in static mode, to minimize the effect of this failure.

Claims

Electronic device (1) for controlling a lighting module of an automotive lighting device (10) comprising light sources (6) to perform a lighting function; wherein
the electronic device (1) comprises a controlling unit (2, 3) configured to feed the light sources when the lighting function is active and not to feed the light sources when the lighting function is inactive;
the electronic device (1) comprises a diagnosis unit (4) and a storage unit (5), the diagnosis unit (4) being adapted to sense a failure of any of the light sources (6) when the light function is active and to emit a failure alert intended to be received by the storage unit (5), either directly or by means of an element of the electronic device, if a failure is sensed in any of the light sources (6), the storage unit (5) being able to keep this failure status for a lapse of time even without being powered;
the controlling unit (2, 3) is adapted to read the failure status stored in the storage unit (5) to control the lighting device (10); and
the controlling unit is adapted to feed the light sources in at least two different modes, the mode depending at least on the failure status read from the storage unit.
Electronic device according to claim 1, wherein the storage unit (5) is a memory cell separated from the controlling unit.
Electronic device according to claim 2, wherein the storage unit (5) comprises a capacitor and MOSFET transistors, so that two consecutive writing operations are allowed with less than 200 ms between them.
Electronic device according to any of claims 2 or 3, wherein the storage unit (5) comprises a capacitor configured to store the failure status, the capacitor being also configured to discharge if the storage unit does not receive any failure alert during a time interval comprised between 2 and 5 seconds.
Electronic device according to any of claims 2 to 4, wherein the storage unit comprises a Zener diode configured to provide the failure status to the controlling unit.
Electronic device according to any of claims 2 to 5, wherein the storage unit comprises switching transistors and is configured to store the failure status by switching the switching transistors when the diagnosis unit provides a failure alert.
Electronic device according to any of the preceding claims, wherein the lighting function is a turning indicator.
Electronic device according to claim 7, wherein the different modes comprise a first static mode, where all the light sources are activated and deactivated at the same time, and a second dynamic mode, where the light sources are sequentially activated.
Electronic device according to any of the preceding claims, wherein the controlling unit is configured to receive the failure alert from the diagnosis unit and is configured to send the failure alert to the storage unit with instructions to store it or not.
Electronic device according to any of the preceding claims, wherein the storage unit comprises means for storing at least two different failure status, each failure status being associated to one of the light sources.
Electronic device according to any of the preceding claims, wherein the light sources are solid-state light sources, such as LED.
Method for controlling a lighting device comprising an electronic device according to any of the preceding claims, the method comprising the steps of
the controlling units activates the lighting functionality and control the light sources in a first standard mode;
the diagnosis unit checks a failure status of at least one of the light sources by means of the diagnosis unit;
in the event any of the light sources fails, the diagnosis unit sends a failure alert to the storage unit;
the storage unit stores a failure status; and
the controlling unit checks the failure status of the storage unit by means of the controlling unit;
the controlling unit controls the light sources according to the failure status read on the storage unit.
Method according to claim 12, wherein after the step of controlling the light sources according to the failure status the method cycles back to the step of checking a failure status by means of the diagnosis unit.
Automotive lighting device (10) comprising an electronic assembly (1) according to any of claims 1 to 11.
Automotive lighting device (10) according to claim 14, further comprising a first optical element 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, the optical element being at least one of a lens, a light guide, a reflector or a collimator.