WO2012059329A1

WO2012059329A1 - Light emitter module comprising a sensor of light coupled out of a light guide

Info

Publication number: WO2012059329A1
Application number: PCT/EP2011/068323
Authority: WO
Inventors: Elena Justus-Bischler; Bernhard Bayersdorfer; Christoph Nitzl
Original assignee: Lisa Dräxlmaier GmbH
Priority date: 2010-11-03
Filing date: 2011-10-20
Publication date: 2012-05-10
Also published as: DE102010043295A1; DE102010043295B4

Abstract

The present invention relates to interior lighting, in particular using LEDs, as used, for example, in automobiles. Such lighting can be so-called ambience lighting or effect lighting, but also signal lighting (for example in case of danger). The light emitter module according to the invention comprises an LED (5), a sensor (2), the LED (5) and the sensor (2) being connected to each other via a control unit, a light guide (4A-B) that can be introduced into the module and is located opposite the LED (5), and a housing (G) in which the LED (5) and the sensor (2) are accommodated. The sensor (2) is arranged in such a manner that it can detect light coupled by the LED (5) into the light guide (4A) and light that is again coupled out of the light guide (4B).

Description

LIGHT MASTER MODULE WITH SENSOR OF LIGHTING OUT OF LIGHTING OUT LIGHT

1. Technical area

The present invention relates to interior lighting, in particular by means of LEDs, as used for example in automobiles. Such lighting can be a so-called ambient lighting or effect lighting, but also a signal lighting (eg. In case of danger).

2. State of the art

In the field of ambient lighting for vehicles, in addition to already known monochromatic lighting, there is a desire for multicolor. In-house, it is known to implement such multicolor with multiple single-color LEDs. However, the available space is small, which is why the coupled to the LEDs light guide should not exceed a certain diameter. Since the light pipe is to be ensured further homogeneous over long lengths, it is usually assumed that a maximum light pipe diameter of 5.5 mm. With such a diameter, however, one can couple light by means of a maximum of two monochromatic LEDs.

By mixing the intensity of these two LEDs, in addition to a specific color of an LED, additional mixed colors can be generated, which lie in the CIE standard table on connecting lines between the pure colors.

In order to be able to further increase the variety of colors in the vehicle, and even to be able to provide an unlimited number of colors, it would be advantageous to use one RGB LED instead of several single-color LEDs. at In addition, use of such an RGB LED could be used with a diameter of 3.5 mm.

A color sensor could be used to control the RGB LED. However, the problem arises that the light emitted by the RGB LED light must be thoroughly mixed before it reaches the color sensor. A direct irradiation in the color sensor is not possible because the intensity and color coordinates are falsified.

As the prior art, the document DE 10 2006 099 551 B4 is known, which relates to an apparatus for generating light of a freely selectable color with a plurality of monochrome bulbs. A controller is designed here as a microprocessor and connected by means of a line with a temperature sensor for detecting the temperature of the LEDs. Likewise, the controller is connected by means of a line to a photodiode, which is arranged facing a light exit surface of a prism whose light entrance surface faces the photodiodes.

As a further prior art, the document DE 10 2008 039 364 AI is known, which relates to a semiconductor light-emitting device. The semiconductor light source may include at least one LED. Furthermore, a plurality of same-colored and / or differently colored LEDs may be present.

Another prior art, DE 10 2008 025 865 AI, relates to a method for operating an LED module consisting of a number of different colored LEDs. From this prior art, the problem already arises that in the case of the new procurement of an RGB-RGBA or hybrid LED module, only the reproducibility of defined LED light will enable the use of LED technology in general lighting. Only a color sensor that determines the color location and thus can calculate the individual color components, allows accurate color control.

3. Subject of the invention

The object of the present invention is to provide a module with an LED and a sensor, in which the components can be accommodated in a small installation space, and at the same time the light emitted by the LED is hardly attenuated by the measurement with the sensor.

To achieve this object according to the invention, a module according to claim 1 is provided. exemplary

Embodiments of the invention are described in the dependent claims.

The present invention provides for this purpose a light emitting module, in which an LED and a sensor are accommodated. In the light emitter module, a light guide is inserted during assembly and fixed there. The basic idea of the present invention is to detect the light coupled into the light guide by the LED through the sensor. The sensor transmits the measurement results to a control unit, which in turn controls the LED.

The components mentioned can thus be accommodated in a module in a small space. Also, the sensor needs to be calibrated / tuned only once for a specific module. The control is thus independent of the changing geometry of the light guide.

The control can be used not only for color matching but also for brightness control. Also, the present invention prevents the light emitted from the LED from being adversely affected by the measurement. In a particular embodiment, it is therefore provided that locking lugs of a light guide, which are provided for its attachment to the module, are used to deflect a small portion of the light coupled into the light guide in the direction of the sensor. For this purpose, this proportion of light is coupled out of the light guide again, and guided to the sensor.

In an alternative embodiment, the sensor is fixed to the housing such that its detection surface is opposite the optical fiber, and the sensor can thus detect the mixed-in light already coupled into the optical fiber.

In a preferred embodiment, the LED is a so-called RGB LED with a plurality of color diodes. Typically, an RGB LED is equipped with a green, a blue and a red color diode. By mixing the individual colors, a broad color spectrum can be realized.

Further, it is preferred that the sensor is calibrated during assembly in the light emitter module with respect to the LED also already mounted in the light emitter module. Thus, the sensor can be adjusted to the conditions in the specific module. This is particularly advantageous if - in the case of an RGB LED - depending on the light emitter module different color components are detected by the sensor.

Thus, the control unit connected to the LED and the sensor based on the measurement data of the sensor can control the LED targeted, and thus set the desired color exactly. It is provided in a further preferred embodiment that the optical fiber used has a diameter between 2-5 mm, preferably about 3.5 mm. The size of about 3.5 mm is a commonly used size. Thus, in the stated diameter range ensures the light pipe homogeneous over relatively long distances.

In a further embodiment, the sensor has a detection surface which points in the direction of emission of the LED. This makes it possible to realize an extremely compact design.

In a preferred embodiment of the present invention, the LED and the sensor are fixed on a common base. As a result, the relative orientation of the sensor to the LED can be ensured. In particular, a circuit board is used as a common base (PCB = printed circuit board).

For fixing the light guide to the light emitter module, the light guide can have so-called latching noses. These locking lugs are used in one embodiment of the present invention to deflect a portion of the light in the light guide, and to guide this light portion to the sensor. Accordingly, the locking lugs, in addition to the mechanical mounting of the light guide in the light emitting module fulfill another task. The deflected for the measurement with the sensor light reduces the optical fiber property of the light guide only insignificantly, since it is only a small part of the light coupled into the light guide.

In one embodiment, it is provided that the light is reflected at a latching nose in such a way that it again passes in sections through the light guide and exits at a position from the light guide. Then it is detected by the sensor.

In a particular other embodiment, the sensor is fixed to the housing of the light emitting module, preferably encapsulated. In this embodiment, the sensor is in this embodiment positioned so as to oppose the optical fiber inserted into the light emitting module so that it can detect a light coupled from the LED into the optical fiber.

For this purpose, it is preferably provided that a portion of the light guide on which the sensor is located, is cloudy, so that at this point a part of the light can be coupled out from the light guide and detected by the sensor.

4. Brief description of the drawings

Fig. 1 shows a beispielhaf e embodiment of the present invention, in which a color sensor is arranged laterally of the light guide in the housing.

Fig. 2 shows a schematic view of a second

Embodiment of the present invention, wherein a detent of the light guide reflects a part of the light to the color sensor.

Fig. 3 shows a schematic view of a third

Embodiment of the present invention, which has a similar structure to the embodiment shown in Fig. 2.

5. Detailed description of the exemplary embodiment

Hereinafter, three preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 1 relates to a first embodiment in which the color sensor 2 is integrated in the housing G of the module according to the invention. In this case, a RGB LED 5 is applied to a printed circuit board 1, on whose opposite side an end portion 4a of a light guide 4A is located when this light guide 4A has been inserted into the module. In Figure 1, this state is shown.

By RGB LED is meant in the context of this application, a LED (light emitter diode) with multiple diodes. This term includes, for example, RGGBs, RGBWs or similar LEDs. The present RGB LED 5 in this case has a plurality of color diodes in the present Au guide form is a diode for green light 6, a diode for blue light 7 and a diode for red light 8. With the help of these diodes 6-8 can large color spectrum can be generated.

Since the end portion 4a of the optical fiber 4A is opposed to the RGB LED 5, the light generated by the RGB LED 5 is coupled into the optical fiber 4A. The detection of the well-mixed light in the light guide by means of the color sensor 2, which may be a true color sensor or RGB sensor.

The sensor 2 was either cast directly in the manufacture of the housing G in this case, or fixed there in a subsequent assembly step (for example by clipping). By fixing the light guide in the housing, there is no posi ionierungsprobleme between color sensor 2 and light guide 4A.

The fixation of the RGB LED 5 on the light guide 4A can be effected by pressing the printed circuit board 1 against the corresponding side of the housing G, thereby positioning it and thus fixing the position of the RGB LED / light guide / sensor components. The detection section of the sensor 2 is aligned perpendicular to the longitudinal direction of the optical fiber 4A in the present embodiment. Thus, a detection of the light already located in the light guide 4A can take place, which has the advantage that the light is already sufficiently mixed. The well-mixed light is coupled out of the light guide at a point of the light guide on which the color sensor 2 is located. For this purpose, this region of the optical waveguide lying opposite the sensor can be roughened in order thus to ensure the exit of a small part of the light coupled in the optical waveguide.

A further embodiment of the present invention is shown in FIG. As in the first embodiment, an RGB LED 5 is mounted on a circuit board 1. Opposite the RGB LED 5, which in turn has a plurality of color diode 6-8, is the end portion of an inserted into the module light guide 4B.

The light guide 4B is provided in this embodiment with locking lugs 4b, which engage in the housing G and the light guide 4B with respect to the housing G, and thus fix the printed circuit board 1. Since both the RGB LED 5 and a color sensor 2 are mounted at defined positions on the circuit board 1, this ensures the relative position of said components to each other.

For detecting the well-mixed light in the light guide 4B (light beams 6a-8a), a scattered light is detected by the color sensor 2, which is reflected by one of the locking lugs 4b through the light guide 4B back to the color sensor 2.

This embodiment is based on the finding that in the presence of latching lugs on a light guide there is always a scattering of the coupled-in light. In In this case, this scattering is used without having to pick up additional light at the coupling-in point (end section 4a). This has the advantage that the intensity of light that is fed into the light guide 4B is not attenuated.

FIG. 3 shows a further embodiment of the present invention whose principle is similar to the second embodiment. However, in this third embodiment, the light at the detent is not reflected within the light guide 4B, but deflected or scattered by the detent 4b via a recess within the housing to the outside. This scattered to the outside light again passes through a further recess in the housing G on the fixed to the circuit board 12 sensor. This has the advantage over the second embodiment that the light is only reflected once (namely at the right detent 4b shown in FIG. 3), while in the second embodiment, after reflection at the detent, further deflections of the light upon exiting the light guide in FIG the interior of the housing G can be expected.

In the embodiments 2 and 3 (Figures 2 and 3), there are various ways to fix the color sensor 2 to the circuit board 1. One possibility is to attach contact pins to the printed circuit board 1 and provide in the housing G guide slots for the pins. On the sensor, a receptacle for the contact pins is provided at the individual outputs. The recording between the springs on the color sensor 2 is smaller than the contact pin diameter, so that a latching of the contact pin and thus a firm contact can be ensured.

Another possibility is to provide the contact pins on the color sensor 2. The contact with the circuit board via so-called mqs section pins. For this, contact holes are available on the board placed, which are smaller in diameter than the contact pins. When pressing the contact pins in the holes material is plastically deformed in the holes, and thus the contact pins engage firmly.

The illustrated in the embodiments 1-3 module of RGB LED 5, color sensor 2, light guide 4A-B and the housing G has the advantage that the color sensor 2 must be calibrated and adjusted only once during assembly of the module. In the case of a changing geometry of the light guide no re-vote must be made. Furthermore, the control can be used not only for color matching, but generally for brightness control.

Accordingly, a wide range of industrial applicability of the present invention opens up. Preferably, this is used for a so-called ambient or effect lighting, for example in an automobile. However, a signal lighting in case of danger or a functional lighting is conceivable. Also, the present module can be constructed as an optical switch when z. For example, an activity (such as a touch) with a finger should change the characteristics of the light, and this is detected to the sensor.

Claims

claims

A light emitting module comprising; an LED (5) and a sensor (2), the LED (5) and the sensor (2) being connected via a control unit, a light guide {4A-B), which can be inserted into the module and is opposite the LED (5), and a housing (G) in which the LED (5) and the sensor (2) are accommodated, wherein the sensor (2) is arranged so that one of the LED (5) in the light guide (4A) coupled and a light extracted from the light guide (4B) can detect light.

2. The light emitting module according to claim 1, wherein the LED (5) is provided with a RGB LED having a plurality of color diodes, in particular a green, a blue and a red color diode (6-8).

3. Light emitter module according to one of the preceding claims, wherein the sensor (2) is calibrated during assembly with respect to the mounted in this light emitting module LED (5). , Light emitting module according to one of the preceding claims, wherein the control unit based on the measurement data of the sensor (2), the LED (5} can control.

5. Light emitter module according to one of the preceding claims, wherein the light guide (4A-D) has a diameter of 2 to 5 mm, preferably about 3.5 mm.

6. Light emitter module according to one of the preceding claims, wherein the sensor (2) has a Detektierflache which points in the direction of emission of the LED (5).

7. Light emitter module according to one of the preceding claims, wherein the LED (5) and the sensor (2) on a common base (1), in particular a printed circuit board, are fixed.

8. Light emitter module according to one of the preceding claims, in which the optical waveguide (433) has latching lugs (4b), at which a part of the light coupled into the optical waveguide (4B) is deflected.

9. Light emitter module according to claim 8, in which the latching lugs (4b) fix the light guide (4B) to the light emitter module.

10. Light emitter module according to claim 8 or 9, wherein the light is reflected on a latching lug (4b) in such a way that it in turn passes through the light guide and exits from the light guide.

11. Light emitter module according to claim 8 or 9, in which the light is reflected on a latching lug (4b) so that it exits at the latching lug (4b) from the light guide.

12. Light emitter module according to one of claims 1-5, wherein the sensor (2) fixed to the housing (G) of the light emitting module, is preferably poured, and in such a way opposite the light guide (4A), that one of the LED (5) in the light guide (4A) can detect coupled light. A light emitting module according to claim 12, wherein a portion of the light guide (4A) opposite to the sensor 2 is roughened.