DETECTOR DEVICE AND AUTOMOTIVE LIGHTING DEVICE

Abstract

The present invention refers to a detector device for detecting a status of at least a first electronic element of an automotive lighting device. This detector device comprises a status detection unit configured to detect a status of the at least first electronic element and to generate a reference signal which depends at least on the status of the first electronic element. It also comprises a comparison signal generator configured to generate a comparison signal and a comparison unit configured to generate a pulse-width modulation signal by comparing the reference signal with the comparison signal.

Claims

1. Detector device for detecting a status of at least a first electronic element of an automotive lighting device, the detector device comprising a status detection unit configured to detect a status of the at least first electronic element and to generate a reference signal which depends at least on the status of the first electronic element; a comparison signal generator configured to generate a comparison signal; a comparison unit configured to generate a pulse-width modulation signal by comparing the reference signal with the comparison signal.

2. Detector device according to claim 1, wherein the status detection unit comprises a reference voltage generator which receives the at least first status signal and is configured to generate different values of reference signals depending on the status of the at least first electronic element, in such a way that the comparison unit is configured to generate a pulse-width modulation signal with a shape which depends on the reference signal.

3. Detector device according to claim 2, wherein the reference voltage generator comprises a switching block to generate different reference signals.

4. Detector device according to claim 1, being further suitable for detecting a status of at least a second electronic element of the automotive lighting device, wherein the status detection unit is also configured to detect the status of at least the second electronic element and the reference signal depends also on the status of the at least second electronic element.

5. Detector device according to claim 4, wherein the comparison unit is configured to generate the pulse-width modulation signal with a duty cycle which depends on the reference signal, in such a way that different status signals make the status detection unit generate different reference signals and this make the comparison unit generate pulse-width modulation signals with different duty cycles.

6. Detector device according to claim 1, wherein the comparison signal is a triangular signal.

7. Detector device according to claim 1, wherein the status is related to a failure status.

8. Detector device according to claim 1, wherein the status detection unit comprises a transistor, such as a MOSFET or a BJT, for each of the electronic elements whose status is to be detected.

9. Detector device according to claim 1, comprising more than one comparison unit and more than one status detection unit, each comparison unit receiving the same comparison signal and one reference signal from one of the status detection units, so that more than one pulse-width modulation signal may be produced at the same time.

10. Detector device according to claim 1, wherein the first electronic element is a light source of one of a turning indicator, a tail function, a stop function, a reverse light or a fog lamp, or other lighting function.

11. Detector device according to claim 10, wherein the light sources are solid-state light sources, such as LED.

12. Automotive lighting device comprising a detector device according to claim 1.

13. Automotive lighting device according to claim 12, further comprising 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, the optical element being at least one of a lens, a light guide, a reflector or a collimator.

14. Detector device according to claim 2, being further suitable for detecting a status of at least a second electronic element of the automotive lighting device, wherein the status detection unit is also configured to detect the status of at least the second electronic element and the reference signal depends also on the status of the at least second electronic element.

15. Detector device according to claim 2, wherein the comparison signal is a triangular signal.

16. Detector device according to claim 2, wherein the status is related to a failure status.

17. Detector device according to claim 2, wherein the status detection unit comprises a transistor, such as a MOSFET or a BJT, for each of the electronic elements whose status is to be detected.

18. Detector device according to claim 2, comprising more than one comparison unit and more than one status detection unit, each comparison unit receiving the same comparison signal and one reference signal from one of the status detection units, so that more than one pulse-width modulation signal may be produced at the same time.

19. Detector device according to claim 2, wherein the first electronic element is a light source of one of a turning indicator, a tail function, a stop function, a reverse light or a fog lamp, or other lighting function.

20. Automotive lighting device comprising a detector device according to claim 2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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:

[0039] FIG. 1 shows a first general scheme of a detector device according to the invention.

[0040] FIG. 2 shows an electric scheme of the comparison signal generator of the detector device according to the invention.

[0041] FIG. 3 shows an electric scheme of the status detection unit and the comparison unit of the detector device according to the invention.

[0042] FIG. 4 shows a lighting device comprising an electronic assembly according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0043] 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.

[0044] 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.

[0045] FIG. 1 shows a first general scheme of a detector device 1 according to the invention. This detector device 1 is suitable for detecting a status of a plurality of light sources 10 of an automotive lighting device.

[0046] The detector device 1 according to this embodiment comprises [0047] a status detection unit 2 configured to detect a status of the light sources 10 and to generate a reference signal 21 which depends at least on the status of the light sources; [0048] a comparison signal generator 3 configured to generate a comparison signal 31; [0049] a comparison unit 4 configured to generate a pulse-width modulation signal 41 by comparing the reference signal 21 with the comparison signal 31.

[0050] As a consequence, the detector device 1 receives the status of several light sources 10 and creates a pulse-width modulation signal which depends on these statuses, by the comparison of a comparison signal 31 with the reference signal generated by the status detection unit 2.

[0051] FIG. 2 shows an electric scheme of the comparison signal generator 3 of the detector device 1 according to the invention.

[0052] This comparison signal generator 3 generates a triangle signal 31 to be used as the comparison signal of the system. A Schmitt trigger cell is used in this embodiment to generate a triangle signal by means of charging and discharging a capacitor. The frequency of this triangle signal depends on the charge and discharge time; in other words, it depends on the capacitor value and may be tuned by choosing a suitable value for this element.

[0053] FIG. 3 shows an electric scheme of the status detection unit 2 and the comparison unit 4 of the detector device 1 according to the invention.

[0054] The comparison unit 4 comprises a comparator which receives two signals: the triangle signal 31 generated by the comparison signal generator 3 and a reference signal 21 produced by the status detection unit 2. The comparator output is a PWM signal 41 with a predetermined frequency and a duty cycle which depends on the status of the elements 10, which are encoded in the reference signal 21. Hence, to generate different PWM levels (different PWM duty cycle values) different reference signals must be used. To do so, a switching block is used in this particular embodiment in order to provide different values of the reference signal, depending on the statuses of the elements to be monitored. This switching block comprises a MOSFET for each element 10.

[0055] FIG. 4 shows a lighting device 20 comprising an electronic assembly 1 according to the invention. This lighting device 20 comprises a turning indicator functionality with a plurality of LEDs 10, which may be activated by the vehicle user.

[0056] The detector device 1 of the invention is configured to provide a single pulse-width modulation signal which comprises information about the statuses of the LEDs 10 comprised in the turning indicator functionality, without using expensive software solutions or micro-controllers.