TECHNICAL FIELD

This invention is related to the field of automotive lighting devices, and more particularly, to the way light patterns are managed when using a Dynamic Bending Light (DBL) functionality.

STATE OF THE ART

Dynamic Bending Lights are increasingly present in current automotive lighting devices, becoming an upgrade to standard headlights and designed to make driving at night easier and safer.

To implement such a lighting functionality, there have been many solutions intended to provide a light pattern in the direction of the movement of the vehicle when it is entering a curve.

Mechanic-based solutions turn the lighting source as the steering wheel does, by means of an angular movement converter which directly uses the turning of the steering wheel to induce a turning in the lighting source. The lights will turn in whatever direction the wheel does, and this range of motion allows the lights to illuminate the road even when taking sharp turns or turning quickly.

This solution has received a huge number of improvements, so that the turning of the light source is more effective and also takes into account different driving circumstances.

An alternative solution for this problem is sought.

SUMMARY OF THE INVENTION

The invention provides an alternative solution for providing a dynamic bending light by a method for controlling a light pattern according to claim1and an automotive lighting device according to claim8. Preferred embodiments of the invention are defined in 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 a first inventive aspect, the invention provides a method for controlling a light pattern provided by an automotive lighting device of an automotive vehicle, wherein a dynamic portion of the light pattern is provided by a matrix arrangement of light sources, the method comprising the steps ofsensing a turn in a steering system of the automotive vehicle;divide the dynamic portion in a first portion and a second portionshifting the operation of the light sources associated to the first portion in the same direction as the sensed turn; andcreate a third portion between the shifted first portion and the second portion.

This method provides a controlled light pattern which includes a Dynamic Bending Light functionality, provided by the same lighting device that provides, for example, the low beam functionality, without moving parts and also being able to adapt to other driving circumstances, such as the driving speed or the presence of cars in the opposite direction.

The shifting in the operation should be understood as displacing one or more columns to the right or to the left, depending on the movement of the steering system, the light pattern provided in the matrix: if the original pattern in one row is, e.g., 0-0-1-1-0, where 0 is a light turned off and 1 is a light turned on, after a 1 column shift to the left, the resulting pattern would be 0-1-1-0-0, and after a 1 column shift to the right, the resulting pattern would be 0-0-0-1-1. The subsequent creation of a third portion should be understood as the activation of the light sources which are associated to the blank spaces created when shifting the first portion. In another example, if the original pattern is 0-0-1-1-1-0-0-0-0-0, and the second portion is defined as 0-0-1 and the first portion is defined as 1-1-0-0-0-0-0, and the turning of the vehicle involves shifting 2 columns to the right, the second portion would remain the same 0-0-1, but the second portion would shift 2 columns to the right, creating 2 columns of blank space: 0-0-1-1-0-0-0. The creation of a third portion between the first portion and the second portion would “fill this blank space”, so that the final light pattern, after joining the first portion, the second portion and the third portion would be 0-0-1-1-1-1-1-0-0-0. The first “1” would belong to the second portion, the next two “1”s would belong to the third portion and the remaining two “1”s would belong to the first portion, which has been shifted to the right.

In some particular embodiments of this method, the light pattern further comprises a fixed beam provided by a first group of solid-state light sources, and the matrix arrangement comprises a second group of solid-state light sources, wherein the sum of the fixed beam and the dynamic portion gives result in the light pattern.

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.

The combination of a fixed beam and a matrix beam arrangement is a very common solution for current headlamps. The matrix arrangement is in charge of providing some lighting functionalities and, with the method of the invention, this matrix beam is also configured to provide a Dynamic Bending Light functionality without adding any additional element.

In some particular embodiments of this method, the third portion is an interpolation between the first portion and the second portion

The third portion fills the gap created when the first portion is shifted according to the turning of the vehicle. In these embodiments, the way of defining the luminous intensity of each pixel would be an interpolation between the column of the shifted first portion which is closest to the third portion and the column of the second portion which is closest to the third portion. In some particular embodiments, this interpolation is linear.

In some particular embodiments, the light pattern is a low beam pattern and the first portion comprises the cut-off of the low beam pattern.

The cut-off is a diagonal line of the low beam pattern, and its shape is important in automotive regulations. The fact that this cut-off belongs to the first portion means that this cut-off is being shifted when the vehicle turns. This is advantageous since the shifted pattern must also comply with the regulations. However, the invention may be also applied to other lighting functionalities without a cut-off, such as the high beam.

In some particular embodiments of this method, before the step of shifting the operation of the light sources, the angular displacement of the steering system is sensed and converted into a number of positions to shift, and then the step of shifting is carried out using this number of positions to shift.

The matrix of solid-state light sources may have many different angular resolutions. Depending on the number and arrangement of these light sources, resolution may vary from 0.01° per light source up to 0.5° per light source. Hence, the angular position of the steering wheel may be translated in a different number of columns of the light array, depending on the density of these light sources in the array arrangement.

In some particular embodiments, this method further comprises the step of internally checking the luminous intensity in one point of the light pattern.

Due to the changes which are caused in the total light pattern due to the shifting of a portion of it, it is sometimes necessary to check if some of the light points which are regulated by the official law still accomplishes its luminous intensity standards.

In a second inventive aspect, the invention provides an automotive lighting device comprisinga first group of solid-state light sources, intended to provide a fixed beama matrix arrangement of solid-state light sources, intended to provide a dynamic beamcontrol means for accomplishing the steps of the method according to the first inventive aspect.

This automotive lighting device is configured to provide a Dynamic Bending Light functionality without moving parts, and using elements which are already available, but with a new configuration.

In some particular embodiments, the matrix arrangement comprises at least 2000 solid-state light sources.

This invention can be useful for many types of lighting matrix/array-based technology, from the simplest one, with only a few thousands light sources, to more advanced ones, with several hundred thousand light sources.

