Lighting structure for vehicles

Abstract

Illuminating structure (1) for vehicles with two or more partial illuminating surfaces (A1, A2, A3 and A4) arranged at an externally visible position of the vehicle, wherein the partial illuminating surfaces are assigned light sources (L1, L2, L3 and L4) which, controlled by a control device (2), can be changed in intensity or in intensity and color depending on the time, wherein the control device (2) is configured to - the individual light sources (L1, L2, L3 and L4) within predefined and definable upper and lower limits ( I min ( m → i ) , I max ( m → i ) ) for the overall intensity ( I ges ( hv → , t ) ) to control the lighting structure (1) with the partial lighting surfaces (A1, A2, A3 and A4), and - the individual light sources (L1, L2, L3 and L4) with regard to their intensity and / or color depending on the parameters supplied to them relating to the driving situation (v, E)v , GPS) within the specified, definable upper and lower limits for the overall brightness of all partial illuminated areas, characterized in that parameters relating to the driving situation are the vehicle speed and / or the ambient light and / or location coordinates and / or values ​​from sensor means detecting the state of a driver.

Description

[0001] The invention relates to a lighting structure for vehicles with two or more partial lighting surfaces, which is arranged at an externally visible position of the vehicle, wherein light sources are assigned to the partial lighting surfaces which, controlled by a control device, can be changed in their intensity and / or color depending on the time.

[0002] The partial light areas can together represent a signal light or lighting function, e.g. daytime running light, parking light, direction indicator, etc., but dipped beam and cornering light are also possible in principle.

[0003] A lighting structure of this type is known, for example, from the applicant's published application AT 522 545 A2. This known device serves as a status indicator for the condition of an operationally relevant component of a motor vehicle, wherein a lighting structure powered by at least two light sources is arranged at an externally visible position of the vehicle, and a control circuit is assigned to the light sources, which is configured to control the light sources depending on a status signal representative of the condition of the operationally relevant component, such that the luminance and / or color along the lighting structure indicates the condition of the component on a scale.

[0004] From the prior art, DE 10 2011 055 598 A1 discloses a method for controlling at least one lighting function of a headlight, wherein the brightness of the lighting function follows a control curve, according to which it is regulated essentially continuously increasing from a lower limit to an upper limit and then continuously decreasing back down to the lower limit. DE 10 2004 002 334 A1, on the other hand, discloses a control circuit for the lighting system of a motor vehicle with a rear light and a sensor for detecting ambient brightness. To avoid confusing following road users with the illumination of the rear light, the rear light can be controlled by a dimmer according to a decreasing ambient brightness over time.Finally, utility model DE 20 2008 017 397 U1 describes a first and a second light source which can be controlled by a control unit in order to assign a time-varying profile of their light intensity to each.

[0005] In the design of vehicles, especially automobiles, increasing emphasis is placed on a pleasing yet striking appearance, which also affects the design of headlights and signal lights, which on the one hand must meet the lighting technology and legal requirements, but on the other hand should also meet different aesthetic considerations.

[0006] LEDs are frequently used, for example in conjunction with light guides, to create luminous surfaces that are positioned in a way that is visible from the outside. Such luminous surfaces can be used, for example, in headlights or for turn signals. It is known that the brightness of these light sources can be controlled, for example dimmed, using current limiting or PWM circuits.

[0007] For the sake of simplicity, the term "illuminating surfaces" used below in connection with the invention is to be understood as representing the light-emitting surfaces recognizable by an observer, which can be planar, but can also be represented by one or more reflectors or other structures, such as optical elements, e.g. lenses, mirrored and / or textured aperture parts or reflectors.

[0008] A problem for the designer is posed by legal requirements that specify a minimum and / or maximum intensity distribution or certain minimum / maximum intensity values ​​at predetermined measuring points of a particular luminaire. These requirements must also be met by lighting devices whose individual illuminated areas are controlled to vary their brightness over time by controlling corresponding individual luminaires. In most cases, the law specifies an intensity distribution or an illuminance distribution on a given illuminated surface, e.g., a wall at a distance of 25 meters.

[0009] One objective of the invention is to create a lighting structure in which this problem is solved.

[0010] This problem is solved with a luminaire structure of the type mentioned above, in which, according to the invention, the control device is configured to control the individual light sources with the partial luminaire surfaces depending on predetermined, definable upper and lower limits for the overall intensity of the luminaire structure.

[0011] In this way, the designer has the freedom to control individual light sources or illuminated surfaces within a wide range with regard to their brightness or color, as long as the overall brightness remains within certain predefinable limits.

[0012] A suitable variant is characterized by the fact that the control unit is designed to control the individual light sources while maintaining a predetermined and definable minimum total illuminated area of ​​the lighting structure. This also fulfills the frequently encountered requirement that a minimum illuminated area of ​​the lighting structure must be present and illuminated.

[0013] In a simple and cost-effective variant, it can be advantageous if the upper and lower limits for the total intensities of all partial illuminated areas and / or the size of the minimum total illuminated area of ​​the luminous structure are stored in a memory.

[0014] In another embodiment, the control device can be configured to control the rate of change of the control of the individual light sources with regard to intensity and / or color depending on parameters supplied to it relating to the driving situation.

[0015] According to the invention, the control device is designed to control the individual light sources with regard to their intensity and / or color depending on parameters supplied to it relating to the driving situation, within the framework of the predetermined, definable upper and lower limits for the overall brightness of all partial illuminated surfaces.

[0016] It is intended that the parameters relating to the driving situation are the vehicle speed and / or the ambient light and / or location coordinates and / or values ​​from sensor devices that detect the condition of a driver.

[0017] The invention, along with its further advantages, is explained in more detail below using exemplary embodiments illustrated in the drawing. These show - Fig. 1. Using a schematic block diagram, the control of, for example, a lighting structure having four partial lighting surfaces, - Fig. 2 a to 2c, for example, diagrams of intensity distributions, - Fig. 3 a diagram with a set of measurement points, - Fig. 4. A time diagram showing an example of the overall intensity curve. - Fig. 5 four luminous sub-segments of a luminous structure according to the invention, - Fig. 6. For example, temporal profiles of time-dependent scaling factors of individual light segments, - Fig. 7. An example of a different way of controlling four light sources and - Fig. 8 the to Fig. 7. The corresponding temporal progression of the scaling factors.

[0018] Fig. Figure 1 shows a light structure 1 with four partial light-emitting surfaces A1, A2, A3 and A4, where these light-emitting surfaces are illuminated in this case via light guides F1, F2, F3 and F4 by light sources L1, L2, L3 and L4. The light sources can be, for example, light-emitting diodes, but the light sources can also be directly integrated into the light-emitting surfaces, for example in versions with luminescence or OLED technology.

[0019] The light sources are controlled by a control circuit 2, which can be, for example, a microcomputer. A memory 3 is assigned to the control circuit 2, and the control circuit 2 receives signals from a speed sensor 5, a brightness sensor 6, and a navigation system 7 from an on-board computer 4.

[0020] The control circuit 2 is now configured to control the individual light sources L1, L2, L3, and L4 according to predefined upper and lower limits for the overall intensity of the luminous structure 1 with its partial luminous areas A1, A2, A3, and A4, which are stored in memory 3. These limits are usually legal requirements that specify a minimum and / or maximum brightness for a particular luminaire or its entire luminous area, and these requirements must also be met by lighting devices whose partial luminous areas are controlled with variable brightness over time by appropriately controlling the associated individual luminous areas. Thanks to the invention, these criteria can be met, although the designer has the freedom to control individual light sources or...The brightness and color of the illuminated surfaces can be controlled as desired within a wide range, as care is taken to ensure that the overall brightness remains within the specified limits.

[0021] The control circuit 2 is furthermore also designed to control the individual light sources L1, L2, L3 and L4 while maintaining a predetermined and definable minimum total luminous area of ​​the luminous structure 1, whereby the size of the minimum total luminous area is also stored in the memory 3.

[0022] Furthermore, the control circuit 2 is configured to control the rate of change of the control of the individual light sources L1, L2, L3 and L4 with regard to intensity and / or color, depending on parameters supplied to it relating to the driving situation. These parameters v, E vGPS can be derived, as in the example shown, from the driving speed supplied by sensor 5, and / or the ambient light level supplied by sensor 6, and / or from the position of the vehicle supplied by location coordinates generated by the navigation system 7.

[0023] Thanks to the invention, the legally required light distribution can be met in every operating state, and a virtually constant light distribution (intensity or illuminance distribution) is ensured even with time-varying luminance distribution (appearance of the light function). The individual light sources can be controlled according to a predefined, time-changing pattern, which can be freely programmable or fixed.

[0024] As mentioned previously, the rate of change over time can be influenced by various factors: Not very dynamic, e.g., during high-speed motorway driving; influenced by the steering angle or GPS information.

[0025] More dynamic in urban traffic, e.g. at speeds below 70 km / h, influenced by road light detection or GPS information for urban traffic, depending on the driver's mood / attention / fatigue state as determined by sensor systems.

[0026] When the vehicle is stationary: changes can also be made very dynamically, for example when locking or unlocking the vehicle, also with personalization to the driver (young, old, male, female, playful, etc.).

[0027] Analogous to the control of the rate of change by the control circuit 2, the individual light sources L1, L2, L3, and L4 can be controlled with regard to their intensity and / or color depending on parameters related to the driving situation supplied to them. In both cases, this control naturally takes place within the upper and lower limits for the total brightness of all partial illuminated areas A1, A2, A3, and A4 stored in memory 3. Likewise, the minimum size of the total illuminated area stored in memory 3 is maintained.

[0028] The algorithm required for control can, in principle, be implemented as an explicit analog or digital control, which can result in cost reductions. The function of the control device should then be understood in this context.

[0029] For even greater control flexibility, using a microcontroller can be advantageous. This is particularly useful if additional control variables, such as speed, brightness, the driver's mood, or similar factors, are to be incorporated into the algorithm. In this case, the control unit is equipped with at least one microcontroller. The individual parameters, such as the current intensity of the respective illuminated areas, are stored in the microcontroller's memory (see memory 3 of the...). Fig. 1, which is shown as representing at least one storage device. Another advantage is that such controllers can be used as a standard in different projects, thus achieving cost savings through higher production volumes without sacrificing flexibility in the design of the control algorithm.

[0030] The following examples show how to determine the control values ​​for the light sources, with reference to the Fig. Reference is made to sections 2a to 2c.

[0031] The respective intensity distribution of a partial illuminated area A1, A2, A3 and A4 is shown below in an angular coordinate system. Fig. 2 is denoted by h, the horizontal angle, and v, the vertical angle. In automotive lighting technology, the intersection point is usually denoted by hv – generally the point towards which the vehicle's direction of travel is directed. Each point in the angle diagram can be represented by a vector. hv→ be determined. With Ii(hv→) is the light intensity of the i-th subsurface at the point vector hv→ vector hv.→

[0032] A function a i(t), whose value can lie between 0 and 1, and which can also be referred to as the time-dependent scaling factor of each partial light area, determines the temporal dependence of each i-th light distribution, so that the sum of all light intensity distributions can be defined in mathematical form as follows: Iges(hv→, t)=∑i=1nai(t)⋅Ii(hv→)

[0033] In automotive lighting technology, upper and lower intensity limits are specified for various lighting functions at certain measuring points. These limits are determined by both customer requirements and legal regulations, within which the measured value must fall. This set of measuring points is described below. Fig. 3, with a→i The upper and lower limits at the measuring point are designated as follows: Imin(m→i) and Imax(m→i) designated.

[0034] It is now necessary to design a set of partial light distributions and to define the scaling factors ai(t) in such a way that for all measurement points m→i at every point in time t the following inequality is satisfied Imin(m→i) <Iges(m→i,t)<Imax(m→i)

[0035] In Fig. Figure 4 shows an exemplary intensity curve that satisfies the above inequality.

[0036] Fig. Figure 5, on the other hand, shows, for example, schematically four illuminated sub-segments of a daytime running light, wherein with Li(∝→,t) the luminance distributions that change over time t, thus the respective appearance of the sub-segments, e.g. designed as light guides, from an observer position ∝→ These segments are designated. The segments generate these intensity distributions. Ii(hv→), which comply with legal requirements and customer specifications.

[0037] Two possible progressions of the functions a1(t) to a4(t) of four individual light sources L1...L4, which are designed, for example, as light-emitting diodes, and the light sources according to the arrangement Fig. 1 can correspond to are in Fig. Figure 6 shows the first example with solid lines and the second example with dashed lines.

[0038] Fig. Figure 7 schematically shows another embodiment of the invention, in which the control circuit 2 controls two series circuits of light sources L1+L3 and L2+L4 respectively, and each series circuit has a function b i (t) is assigned, whose value can again lie between 0 and 1, and which defines the temporal dependence of each of the two light distributions. An example of the course of these functions b i (t) is in Fig. 8 shown.

Claims

[1] Lighting structure (1) for vehicles with two or more partial lighting surfaces (A1, A2, A3 and A4) arranged at an externally visible position of the vehicle, wherein the partial lighting surfaces are assigned light sources (L1, L2, L3 and L4) which, controlled by a control device (2), can be changed in intensity or in intensity and color over time, wherein the control device (2) is configured to - the individual light sources (L1, L2, L3 and L4) within predefined and definable upper and lower limits (Imin(m→i), Imax(m→i)) for the overall intensity (Iges(hv→, t)) to control the lighting structure (1) with the partial lighting surfaces (A1, A2, A3 and A4), and - the individual light sources (L1, L2, L3 and L4) with regard to their intensity and / or color depending on the parameters supplied to them relating to the driving situation (v, E) v, GPS) within the specified, definable upper and lower limits for the overall brightness of all partial illuminated areas, characterized by that parameters relating to the driving situation include vehicle speed and / or ambient light and / or location coordinates and / or values ​​from sensor devices that detect the condition of a driver. [2] Light structure (1) according to claim 1, characterized by , that the control device (2) is configured to control the individual light sources (L1, L2, L3 and L4) while maintaining a predetermined and definable minimum total luminous area of ​​the luminous structure. [3] Light structure (1) according to claim 1 or 2, characterized by , that the upper and lower limits for the total intensities of all partial luminous areas and / or the size of the minimum total luminous area of ​​the luminous structure are stored in a memory (3). [4] Light structure (1) according to claim 1, characterized bythat the control device is designed to control the rate of change of the control of the individual light sources (L1, L2, L3 and L4) with regard to intensity and / or color depending on parameters supplied to it relating to the driving situation. [5] Light structure (1) according to claim 4, characterized by that parameters relating to the driving situation include vehicle speed and / or ambient light and / or location coordinates and / or values ​​from sensor devices that detect the condition of a driver.

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