DE102008008884B4 - Vehicle lighting system - Google Patents

Abstract

Vehicle lighting system
- with a detection device (6) for detecting a solid angle (R1) in which a road user is located,
- with a lighting device (1) for emitting signal light with a solid angle-dependent spectral distribution and/or a solid angle-dependent intensity,
- with a signaling control element (8) and
- with a control device (7) which is coupled to the detection device, the lighting device and the signalling control element and which is arranged in such a way
that the solid angle-dependent intensity and/or the solid angle-dependent spectral distribution of the emitted light in response to the actuation of the
signaling control element and the detection of a spatial angle in which a road user is located is varied,
where the signal light is directed into the spatial angle in which the road user is located,
- with a periodically changing intensity and/or
- with an intensity modulated by a periodic signal and/or
- with a changed spectral distribution
is emitted.

Description

The invention relates to a vehicle lighting system.

For example, from the DE 198 22 142 A1 A headlight with variable light intensity distribution is known. This headlight is designed so that the light intensity is set to zero within a variable range to avoid dazzling an oncoming vehicle.

In addition, vehicle lighting systems with a signal light (headlight flasher) are known, which can be activated by means of a signaling control element.

The invention is based on the object of providing a vehicle lighting system that is improved compared to the prior art.

This problem is solved by the features of the independent patent claim. Advantageous developments of the invention can be found in the dependent claims.

The invention is based on a lighting device designed to specifically emit signal light with different intensities and/or spectral distributions into different solid angles (each with a different radiation direction or main radiation direction). This lighting device is then controlled, for example, when a signal light is activated by means of a signaling control element, in such a way that the intensity and/or spectral distribution of the light emitted into the different solid angles (with different radiation directions) is adjusted depending on the environment, in particular depending on the presence and/or position of other road users (driver, vehicle, pedestrians, animals).

For this purpose, a vehicle lighting system preferably provides a detection device for detecting a solid angle in which a road user, in particular an oncoming road user, is located. Furthermore, a lighting device, in particular a vehicle headlight, is provided for emitting signal light with a solid angle-dependent and thus radiation direction-dependent intensity (average intensity or instantaneous intensity), in particular luminous intensity, and/or a solid angle-dependent and thus radiation direction-dependent spectral distribution.

A control device, for example a processor device, is coupled to the detection device, the lighting device and a signaling control element, in particular a lever, a rocker switch, a button or a switch, and is configured such that the solid angle-dependent (direction-dependent) intensity and/or the solid angle-dependent (direction-dependent) spectral distribution of the emitted signal light is varied, modified or adjusted permanently (for example as long as the road user can in principle be illuminated by the lighting device), temporarily or intermittently in response to the actuation of the signaling control element and the detection of a solid angle in which a road user, in particular of a predetermined type or class, is located.

This ensures that signal light is specifically emitted into specific spatial angles, where, for example, another road user is located, with an intensity that is different from a "normal" intensity (usual for vehicle headlights or other solid angles) and/or with a spectral distribution that is different from a "normal" spectral distribution (usual for vehicle headlights or other solid angles). The modified intensity and/or the modified spectral distribution are preferably selected in such a way that they are advantageous for the perception of other road users and/or the perception by other road users.

The control element or the system operation can preferably also be designed in such a way that a selective selection of at least one road user from a plurality of road users detected by the detection device is enabled. The control element can be designed in such a way that, upon a single actuation, the nearest road user or the road user with whom a collision is most likely is selected. Further actuation of the control element, for example, selects additional road users. The control element can also be connected to a graphical interface, for example a display, through which several road users detected by the detection device are displayed.

Preferably, the signal light is emitted into a solid angle in which the road user is located, with an increased intensity, in particular compared to an adjacent solid angle in which no road user is detected. By detecting a road user and actuating a signaling control element, the intensity of the signal light emitted into the solid angle in which the detected road user is located is increased, while the intensity of the signal light emitted into a spatial angle in which no detected road user is located remains essentially the same or at least does not increase as much as the intensity of the signal light that is emitted in the spatial angle in which the detected road user is located. This means that the signal is only specifically emitted in a spatial angle with the detected road user and, if applicable, their immediate surroundings. This makes it easier for the user of the vehicle lighting system to perceive other road users. The energy consumption of the signal light is low. The signal light is only perceptible to the other road user or is particularly clear to the other road user. Other people, for example in surrounding houses, are not unnecessarily disturbed. Reflection glare effects that could be annoying for the user of the signal light are reduced.

It is particularly preferred that the signal light is emitted into a solid angle in which the road user is located, with an intensity that changes over time, in particular periodically, for example it is activated and deactivated at a predetermined frequency or is modulated with a periodic signal, such as a sine signal or square wave signal. The time period is preferably so long that the change in intensity can be perceived in resolution by the other road user. A period length that is greater than 0.025 seconds is preferred and, advantageously, additionally less than 0.5 seconds. For example, to increase the signal effect in response to the actuation of the signaling control element and the detection of a solid angle in which a road user is located, the intensity of the signal light emitted into the solid angle is switched back and forth between several predetermined intensities.

An advantageous embodiment provides that the signal light is emitted into a solid angle in which the road user is located with a modified spectral distribution, particularly compared to a neighboring solid angle in which no road user is detected. By detecting a road user and activating a signaling control element, the spectral distribution of the signal light emitted into the solid angle in which the detected road user is located is modified, while the intensity of the signal light emitted into a solid angle in which no detected road user is located remains essentially the same or at least is not changed as much as the spectral distribution of the signal light emitted into the solid angle in which the detected road user is located. This makes it easier for the user of the vehicle lighting system to perceive another road user—highlighted in color by the signal light—and/or reduces the glare of the other road user.

It is preferably provided that the lighting device is controlled by the control device in such a way that the spectral component of the blue light in relation to the spectral component of the red or yellow-red light of the signal light emitted into a solid angle in which a road user, in particular his eyes, is located is smaller than in one, in particular adjacent, solid angle or than in several or the adjacent solid angles in which or in which no road user is located.

This ensures that other road users can still be clearly seen by the vehicle lighting system based on the longer-wavelength signal light or the signal light shifted to a reddish hue, but that other road users are not as dazzled by the longer-wavelength signal light as they would be by the signal light with "normal" light distribution. The intensity of glare to human eyes depends not only on the light intensity hitting the retina, but also on the spectral properties of this light. Thus, the shorter-wavelength spectral components are more likely to dazzle than the longer-wavelength spectral components. This effect is also due to the human dual visual system, with daytime vision perceived primarily by cones and night vision perceived by rods, which is about 200 times more sensitive. After being dazzled by xenon light, for example, the eyes of a dazzled driver require a long adaptation period to readjust to night vision. This adaptation time is much longer than the normal adjustment of the sensitivity of the human eye. To prevent drivers of oncoming vehicles on country roads from being dazzled by strong xenon signal light, for example, the bluish or shorter-wavelength components of the signal light emitted in the corresponding direction are attenuated, deactivated, filtered, or even prevented from being emitted at all by the headlight design. Nevertheless, these oncoming vehicles are still clearly visible due to the illumination of the remaining reddish or longer-wavelength signal light, or even more so due to the colored markings.

A particularly advantageous vehicle lighting system provides that the spectral distribution of the signal light emitted into a solid angle in response to the actuation of the signalling control element and the detection of a road user, in particular of a given type or class, is shifted or changed in this solid angle in favour of long-wave components.

Alternatively, in response to the actuation of the signaling control element and the detection or presence of another road user, in particular of a given type or class, in this solid angle, the center of gravity wavelength (center of gravity wavelength divides, for example, the spectral distribution into two ranges with the same integral power or describes the center of gravity of a spectrally distributed emission) of the signal light emitted in this solid angle is advantageously increased - compared to the signal light in this solid angle when no road user is detected in this solid angle - preferably by at least 10 nm, at least 30 nm, at least 50 nm, at least 100 nm or by at least 150 nm.

The signal effect of the signal light is preferably enhanced by, as an alternative or in addition to the measures mentioned, in response to the actuation of the signaling control element and the detection of a solid angle in which a road user is located, the spectral distribution in the solid angle is cyclically switched between several predetermined distributions, for example a "yellow-red distribution" and a "blue distribution", or is continuously changed according to a predetermined temporal function.

For example, when the high beam or low beam is activated, in response to the activation of the signaling control element and the detection of a solid angle in which a road user is located, the intensity of the signal light emitted into this solid angle is increased (compared to the high beam or low beam intensity). In addition or alternatively, the road user is marked, preferably in color, by changing the spectral distribution of the signal light emitted into this solid angle compared to the "normal" high beam or low beam distribution.

Alternatively, when the high beam or low beam is activated, in response to the actuation of the signaling control element and the detection of a solid angle in which a road user is located, the intensity of the signal light emitted into this solid angle is reduced (compared to the high beam intensity or low beam intensity). In addition or alternatively, the road user is marked, preferably in color, by changing the spectral distribution of the signal light emitted into this solid angle compared to the "normal" high beam or low beam distribution. For example, the light from the lighting device is generally emitted with a predetermined spectral "normal distribution" over an entire predetermined beam angle, for example when the high beam or low beam is activated. This "normal distribution" is selected, taking into account various economic, legislative, or technical constraints, in such a way that road users exposed to light with this spectral normal distribution are easily visible. The "normal distribution," for example, is characterized by a certain "normal ratio" of the spectral component of blue light relative to the spectral component of red light. To reduce glare in response to a detected road user, signal light is preferably emitted in the spatial angle attributable to that road user, with the ratio of the spectral component of blue light relative to the spectral component of red light reduced compared to the "normal ratio."

When the low beam and high beam headlights are switched off, the intensity of the signal light emitted into this solid angle is increased (relative to zero), preferably in response to the activation of the signaling control element and the detection of a solid angle in which a road user is located, while the intensity of the light emitted into other solid angles that can generally be illuminated by the lighting device remains the same (zero). In addition, the road user can be marked in color again by changing the spectral distribution of the signal light emitted into this solid angle compared to the "normal" low beam and/or high beam distribution.

As an alternative to these design variants, the intensity in response to the actuation of the signalling control element and the detection of a solid angle in which a road user is located can remain the same and only the spectral distribution of the signal light emitted in this solid angle can be changed compared to the “normal” high beam distribution or low beam distribution.

The detection device can be a known sensor or camera device with associated signal or image processing. The result of the signal or image processing is, for example, the position of a detected road user relative to the vehicle or the lighting device, the movement of a detected road user relative to the vehicle or the lighting device, the size and/or the class (for example, pedestrians or animals) of a The intensity and/or spectral distribution of the signal light emitted in the corresponding solid angle may also depend on the class of a detected road user in that solid angle.

The vehicle lighting system can, in particular, be designed such that the relative movement of another road user is detected or predicted in order to successively emit signal light with a modified intensity and/or with a spectral distribution different from the normal spectral distribution into the spatial angles corresponding to the relative movement. This essentially results in a spatial angle following the movement of the other road user, into which signal light is emitted with a spectral distribution different from the normal spectral distribution.

Another development of the invention provides that information about the intensity and/or the spectral distribution of the ambient light, in particular the light in a specific ambient area or from a specific direction of incidence area, is detected by the detection device or a further detection device, and that the control device is set up in such a way that the solid angle-dependent intensity and/or spectral distribution of the emitted signal light is changed or adjusted in response to the detection of a solid angle in which a road user is located and in response to or depending on the detected information about the intensity and/or the spectral distribution of the ambient light, in particular in order to improve the perceptual contrast.

When generating the signal light for at least one road user, the radiation can be adjusted to be dependent on the direction of radiation so that the light emitted by the vehicle does not reach the road user directly, but rather, for example, after reflection of the light from an object and/or indirectly through targeted illumination of another object, such as a wall or a road barrier. The intensity and/or spectral distribution can be modified, for example, so that the signal light hits a road barrier that is visible from the road user's current spatial position.

Advantageously, the intensity and/or spectral distribution of the signal light is controlled or regulated depending on the intensity and/or spectral distribution of the light reflected by the road user. By recording these parameters, for example, using a camera, the intensity and/or spectral distribution of the signal light that must be emitted towards the road user to achieve the desired signaling effect can be calculated. Thus, the intensity and/or spectral distribution of the vehicle lighting system can be controlled or regulated in such a way that the signal light can be sufficiently differentiated from other lights in the road user's perception given the existing illumination. By determining the necessary parameters of the emitted signal light, "overdose," i.e., unnecessary disturbance or dazzling of the road user, is prevented. In the case of frequent signaling, this can also save energy.

Advantageously, the control of the vehicle lighting system takes into account the intensity and/or spectral distribution of the light detected by the vehicle's surroundings. In particular, the illumination of the vehicle's surroundings provides information on how the intensity and spectral distribution of the signal light can be optimized to create sufficient contrast with the vehicle's background. For example, if the strong reddish light of a sunset or sunrise predominates behind the vehicle, the equally reddish signal light emitted in the direction of the road user can be relatively easily overlooked. Therefore, the vehicle's signal light can be controlled or regulated in such a way that its effectiveness is adjusted despite changing lighting conditions in the vehicle's background. The term "effectiveness" here preferably refers to psycho-optical effectiveness, in particular effectiveness based on the ability of a visual system to recognize intensity and/or color contrasts.

Advantageously, the control of the vehicle lighting system takes into account the intensity and/or spectral distribution of the light emitted, in particular reflected, by parts of the vehicle. The visibility of the signal light in comparison to the surrounding parts of the vehicle (e.g. body parts) depends on how brightly these illuminate (e.g. by reflecting the light from the surroundings). Thus, an increase in the intensity of the light emitted towards a road user can be overlooked by the latter if the body parts surrounding the vehicle's lights are, for example, shining in the sun at that time. A permanently bright signal light can, in turn, cause unnecessary disturbance or distraction to other road users, e.g. at dusk, and at the same time lead to increased energy consumption. use. By controlling the parameters of the emitted signal light with varying levels of illumination of the vehicle itself, depending on the light emitted by parts of the vehicle, the effectiveness of the signal light can be kept largely constant or varied according to a predetermined function. Since comparable effectiveness, in particular psycho-optical effectiveness, can be achieved through different combinations of intensity parameters and spectral distribution, a preferred order for changing these parameters to generate the signal light can be specified. For example, the spectral composition of the light emitted towards a road user is only modified when the increase in intensity necessary to generate a certain required effectiveness of the signal light cannot or must not be adjusted. If the effectiveness of modifying the spectral composition has also been exhausted, the effect of the signal light can be achieved by a temporal variation of the emitted intensity and/or the spectral distribution. The generation of the required effectiveness of the signal light can also be designed in such a way that a “soft” transition between the generation of an intensity contrast and/or a color contrast and/or a temporal change of these parameters is realized.

Advantageously, the spatial distribution of light parameters (intensity profile and/or spectral distribution) in the surroundings of the vehicle and/or in the surroundings of a road user and/or the radiation reflected by the road user is recorded using vehicle cameras. A vehicle camera can record the intensity distribution and/or spectral distribution of the ambient light or the light reflected by another road user. The recording of the light parameters of another road user and their immediate surroundings, as well as the recording of the light parameters in the surroundings of the own vehicle, can be performed using the same image sensor. For this purpose, the corresponding optical device can combine the focused rays from the surroundings of the other road user and the focused rays from a reflective surface that is part of the own vehicle on an image sensor. The spectral distribution and/or intensity distribution of the light coming from a specific direction can be calculated from the ratio of the signals of the corresponding red, blue, and green pixels of the image sensor.

In addition, data from other environmental sensors such as radar, lidar or infrared sensors can be used to calculate the spatial position of the road user, to analyze the traffic situation and the lane layout of a road.

• 1 zeigt eine vereinfachte schematische Darstellung eines Fahrzeugleuchtensystems;
• 2 bis 5 zeigen spektrale Verteilungen des Lichts einer Leuchteinrichtung;
• 6 zeigt eine vereinfachte Darstellung eines Kraftfahrzeuges.

In the following, the invention is explained in more detail by means of examples with reference to the following figures:

• 1 shows a simplified schematic representation of a vehicle lighting system;
• 2 to 5 show spectral distributions of the light of a lighting device;
• 6 shows a simplified representation of a motor vehicle.

1 shows a vehicle lighting system, for example a vehicle headlight with a lighting device 1, a detection device 6 and a control device 7.

The lighting device 1 comprises a light source 2 with a matrix-like arrangement of a plurality of light-emitting diodes 4, 5 (only two are shown as an example) and an optical unit 3, by means of which the generated light is directed in the desired direction.

The entire area illuminated by the LEDs can be divided into several solid angles R1, R2 (only two are shown as examples), each of which is assigned a LED 4, 5. Different radiation directions A1, A2 (central radiation directions or main radiation directions) are assigned to the different solid angles. Depending on the design of the LEDs or the optical unit, the solid angles can, for example, have approximately round or approximately square cross-sections—as shown here.

Each LED 4, 5 can be controlled independently of other LEDs so that the LED emits signal light with a correspondingly different spectral distribution. This can be easily achieved, for example, by each LED consisting of several differently colored LEDs (e.g., blue and yellow-red or blue, red, and green) that can be activated individually, or by controlling or regulating the ratio of the power emitted by these differently colored LEDs. Furthermore, the LEDs can be operated with different duty cycles in the form of pulse width modulation in order to emit different light intensities at different spatial angles.

If the signaling control element 8 is actuated by a user or driver If a road user is detected in a solid angle R1 by the known detection device 6, the corresponding light-emitting diode 4 emitting in this solid angle R1 is controlled in such a way that the light emitted by the light-emitting diode 4 has a different spectral distribution than the light emitted before the road user was detected and/or compared to the light emitted by the adjacent light-emitting diode 5, for example by deactivating the blue light-emitting diode in the light-emitting diode 4. In addition, the light intensity emitted in the solid angle R1 can be reduced or increased compared to the light intensity of the light emitted before the road user was detected or before the signaling control element 8 was actuated, for example by an appropriately adjusted pulse width modulation of the light-emitting diode 4.

A movement of the vehicle lighting system with the vehicle and/or a movement of the other road user and/or an expiration of the signal light timer and/or an end of the actuation of the signaling control element 8 can lead to the LED 4 being controlled or operated normally again after a certain time, and instead the LED 5 being controlled in a different way in order to mark the other road user in color.

Of course, it is also possible that due to the number, proximity or size of the other road user(s), the blue LED in both LEDs 4, 5 and/or other LEDs is deactivated in order to mark the other road user(s) in color.

As an alternative to implementation using various light-emitting diodes, the generation of solid angle-dependent intensities and solid angle-dependent spectral distributions of the emitted signal light can also be achieved using a known digital micromirror system (DMD, DLP).

The 2a and 4a show the spectral distributions of the emitted vehicle light using the example of a vehicle lighting system implemented using blue and yellow LEDs in a solid angle in which no signaling is to take place.

The 3a and 5a show the spectral distribution of a vehicle light with a continuous spectrum also in a solid angle in which no signaling should take place.

The 2b and 3b each show the spectral distributions in a solid angle in which signaling is to take place. In the present example, the road user is in the light of a sunset or in a reddish-lit tunnel. Therefore, in the solid angle in which the road user is located, the proportion of short-wave (blue) light is increased in order to create a color contrast required for the visibility of the signal light. The strength of this increase can be controlled or regulated depending on how brightly the vehicle body is illuminated at that time. If the vehicle is shining in direct sunlight, the intensity of the signaling must be further increased in order to create a sufficient contrast ratio between its lights and the body parts and/or the background illuminated in a certain way.

4b and 5b Each shows the spectral distribution of the light emitted by a vehicle lighting system in a solid angle in which the signal is to be provided. In the current illumination situation of the vehicle and the road user, for example, in bright sunlight behind the vehicle, the power of the blue LEDs is insufficient to generate a sufficient contrast ratio. Therefore, the light emitted by the corresponding blue LEDs or by the corresponding segments of a differently designed vehicle light is varied with a period of, for example, 0.3 seconds. This allows the signaling effect to be sufficiently effective despite very unfavorable lighting conditions.

6 shows an example of capturing the lighting situation with regard to the spatial distribution of the intensity and/or the spectral distribution of the light using a vehicle camera system.

The vehicle 61 is equipped with a camera 62, which is housed, for example, in the mirror base. It is used to analyze the parameters of the light incident from various directions, particularly the respective intensities and spectral distributions. The same camera can simultaneously serve several other applications, e.g., for automatically detecting other road users and measuring their distance. The aperture angle of this camera is selected such that it also captures parts of the vehicle 63 and analyzes the composition of the light reflected by it.

Another light sensor, an existing rear view camera 64, or another camera at the rear of the vehicle analyzes the intensity, radiation direction, and spectral distribution of the light behind the vehicle. Depending on this data, the vehicle lighting system is controlled in such a way that the vehicle from the front is illuminated against the background of the light behind the vehicle. prevailing lighting conditions can be seen sufficiently well. This sensor or camera 64 also captures parts of the vehicle 65. The top-view camera 66 integrated in the exterior mirror can also capture parts of the vehicle body 67 and thus analyze the illumination of these parts. In a simplified embodiment of the invention, coarse-resolution light sensors or photo elements composed of one or a few directed segments can be used as an alternative.

Claims (5)

Vehicle lighting system - with a detection device (6) for detecting a solid angle (R1) in which a road user is located, - with a lighting device (1) for emitting signal light with a solid angle-dependent spectral distribution and/or a solid angle-dependent intensity, - with a signaling control element (8), and - with a control device (7) coupled to the detection device, the lighting device, and the signaling control element, and configured such that the solid angle-dependent intensity and/or the solid angle-dependent spectral distribution of the emitted light is varied in response to the actuation of the signaling control element and the detection of a solid angle in which a road user is located, wherein the signal light is modulated into the solid angle in which the road user is located, - with a temporally periodically variable intensity and/or - with an intensity modulated with a periodic signal and/or - with a modified spectral Distribution is radiated. Vehicle lighting system according to Claim 1 in which the intensity and/or spectral distribution of the signal light emitted into a solid angle is controlled or regulated as a function of the intensity and/or spectral distribution of the light reflected into the solid angle by a road user. Vehicle lighting system according to one of the preceding claims, in which the signal light emitted in a solid angle is controlled or regulated as a function of the intensity and/or the spectral distribution in the surroundings of the vehicle. Vehicle lighting system according to one of the preceding claims, in which the signal light emitted in a solid angle is controlled or regulated as a function of the intensity and/or the spectral distribution of the light emitted by parts of the vehicle. Vehicle lighting system according to one of the preceding claims, in which the intensity distributions and/or the spectral distribution of the light in the surroundings of the vehicle and/or the road user and/or the light emitted by parts of the vehicle are detected by means of an image sensor.