Method for controlling a light pattern and automotive lighting device

Abstract

The invention provides a method for controlling a light pattern (1) provided by an automotive lighting device (10) of a motor vehicle (100). The method comprises the steps of providing a road profile, extracting road features from the road profile, dividing a matrix arrangement into groups of rows, assigning a different shift value to each group of rows, each shift value depending on the road features, dividing each group of rows into a first part and a second part, shifting the operation of the first part of each group of rows of light sources according to the corresponding shift value, and creating a third part between the shifted first part and the second part of each group of rows.

Description

[0001] This invention relates to the field of automotive lighting equipment, and more particularly to a method for managing light patterns when using the Dynamic Curvelight (DBL) function.

[0002] Dynamic cornering lights are increasingly appearing in current automotive lighting systems, serving as an upgrade to standard headlights and designed to make nighttime driving easier and safer.

[0003] To achieve this lighting function, there are already many solutions designed to provide light patterns in the direction of vehicle movement when the vehicle enters a curve.

[0004] The mechanical solution uses an angle-shift converter to rotate the lighting source like a steering wheel. This converter directly uses the rotation of the steering wheel to cause the lighting source to rotate. The light will rotate regardless of which direction the steering wheel is facing, and this range of motion allows the light to illuminate the road, even when making sharp turns or quick maneuvers.

[0005] The solution has been significantly improved, making the direction of the light source more effective and taking into account different driving environments.

[0006] This problem requires an alternative solution.

[0007] This invention provides an alternative solution to the problem through a method for controlling the light pattern provided by automotive lighting equipment of a motor vehicle, wherein the light pattern is provided by a matrix arrangement of light pixels, the method comprising the following steps:

[0008] • Provides road outlines;

[0009] • Extract road features from road contours.

[0010] Arrange the matrix into row groups;

[0011] • Assign a different shift value to each row group, with each shift value depending on the road characteristics;

[0012] • Divide each row group into a first part and a second part;

[0013] • Shift the operation of the first part of each row group of the light source according to the corresponding shift value;

[0014] • Create a third part between the first and second parts of the shift in each row group.

[0015] This method provides a controlled light pattern that includes a dynamic cornering light function, provided by the same lighting device that provides, for example, low beam functionality, without moving parts and is also adaptable to other driving conditions, such as driving speed or the presence of vehicles in the opposite direction.

[0016] The main advantage is that the lighting is more focused on the road compared to other general methods that rely on the position of the steering wheel. In this case, providing the road contour in other ways allows the method to predict behavior, thereby improving road visibility and providing sufficient time to react.

[0017] The shifting operation should be understood as shifting one or more pixels within a row group to the right or left, depending on the shift value: if the original pattern in a row is, for example, 0-0-1-1-0, where 0 represents a light that is off and 1 represents a light that is on, then after shifting 1 to the left, the resulting pattern will be 0-1-1-0-0, and after shifting 1 to the right, the resulting pattern will be 0-0-0-1-1. The subsequent creation of the third part should be understood as the activation of the light source associated with the blank space created when the first part was shifted. In another example, if the original pattern is 0-0-1-1-1-0-0-0-0-0, and the second part is defined as 0-0-1 and the first part is defined as 1-1-0-0-0-0-0, and vehicle steering involves shifting two columns to the right, then the second part will remain the same 0-0-1, but the first part will shift two columns to the right, creating two columns of blank space: 0-0-1-1-0-0-0. Creating a third part between the first and second parts will "fill this blank space" so that the final light pattern after connecting the first, second, and third parts will be 0-0-1-1-1-1-1-0-0-0. The first "1" will belong to the second part, the next two "1"s will belong to the third part, and the remaining two "1"s will belong to the first part, which has been shifted to the right.

[0018] The way the third part is “filled” depends on the light pattern and the car manufacturer’s decision.

[0019] In some specific embodiments, the light pixels are provided by a solid-state light source.

[0020] The term "solid-state" refers to light emitted through solid-state electroluminescence, which uses semiconductors to convert electricity into light. Compared to incandescent lighting, solid-state lighting produces visible light with less heat generation and less energy dissipation. The typically smaller mass of solid-state electronic lighting devices provides greater shock and vibration resistance compared to fragile glass tubes / bulbs and long, thin filaments. Solid-state lighting also eliminates filament evaporation, potentially increasing the lifespan of the lighting device. Some examples of these lighting types include semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), or polymer light-emitting diodes (PLEDs) as the light source, rather than filaments, plasma, or gas.

[0021] In some specific embodiments, each row group corresponds to only one row of the optical pixel matrix arrangement.

[0022] When the number of row groups is high, that is, when each row group contains the minimum possible number of rows, more fine adjustments to the final light pattern are achieved.

[0023] In some specific embodiments, the method further includes a step of applying correction to the luminous intensity of the light emitted by the light pixel.

[0024] In some light patterns where the uniformity of the beam is insufficient to compensate for the variations in light provided by the matrix arrangement, it may be necessary to correct the intensity of some light sources in the light source.

[0025] In some specific embodiments, the correction includes a final mask configured to avoid glare, which includes dimming or turning off some of the shifted light pixels.

[0026] In these embodiments, the purpose of the correction is not to compensate for the total flux or improve the uniformity of the final beam, but to avoid glare to other vehicles. When a line is shifted, the final light pattern may project some light onto the opposite lane. The final mask used to darken or turn off these pixels that project light onto the opposite lane helps to avoid glare.

[0027] In some specific embodiments, the road features are road points, each characterized by its distance from the lighting device and its angle from the lighting device, and the distance and angle of the road points are used to calculate the displacement value.

[0028] A simple way to implement this invention is to capture multiple road points and then use the positions of these points to calculate each shift value, so the shape of the road has a direct impact on the shift pattern of the light pattern.

[0029] In some specific embodiments, each shift value is calculated using the distance and angle of at least one road point.

[0030] The best way to achieve this conversion is to assign a road point to each row group. Since each row group is characterized by the distance between the lighting device and the light projected by that row group, the road point corresponding to that distance will provide an angle value. This angle value can be directly converted into the number of shift positions for that row group.

[0031] A matrix of solid-state light sources can have many different angular resolutions. Depending on the number and arrangement of these light sources, the resolution can vary from 0.01° per light source to 0.5° per light source. Therefore, the angular value of a road point can be shifted across different numbers of columns in the light array, depending on the density of these light sources in the array arrangement.

[0032] In some specific embodiments, the third part of each row group is an interpolation between a boundary pixel of the first part and a boundary pixel of the second part.

[0033] When each row group of the original light pattern is divided into two parts, the first part has boundary pixels and the second part has boundary pixels. These two boundary pixels are adjacent before the first part is shifted, but when the first part is shifted, a third part created between them is contained between these two boundary pixels. Each boundary pixel has a value, and a sensible option is to provide an interpolation between these two values ​​for the third part. In some specific embodiments, the interpolation is linear.

[0034] In some specific embodiments, the light pattern is a low beam pattern and the first portion includes a cutoff line for the low beam pattern.

[0035] The cut-off line is the diagonal of the low beam pattern, and its shape is important in automotive regulations. The fact that this cut-off line belongs to the first section means that when the first section is shifted, the cut-off line is also shifted. This is advantageous because the shifted pattern must also conform to regulations. However, the invention can also be applied to other lighting functions without a cut-off line, such as high beams.

[0036] In some specific embodiments, the step of providing road contours is performed using images from a camera. In some specific embodiments, the step of providing road contours is performed using a global positioning system.

[0037] Cameras are useful for providing road outlines, and the Global Positioning System (GPS) also helps to refine the information provided by cameras.

[0038] In some specific embodiments, the light pixels of the image pattern are grayscale pixels, and more specifically, the luminous intensity of each pixel is based on a scale from 0 to 255.

[0039] Light-emitting modules typically define light patterns using grayscale, where luminous intensity levels range from 0 to 255. This is a method of quantizing light patterns, enabling them to be converted into light data, which is then transmitted and managed by the vehicle's control unit.

[0040] In a further aspect of the invention, the present invention provides an automotive lighting device comprising:

[0041] • Matrix arrangement of solid-state light sources designed to provide light patterns

[0042] • Road contour acquisition device; and

[0043] • Control unit, which is used to perform the steps of the method according to the first aspect of the invention.

[0044] The automotive lighting system is configured to provide dynamic cornering light functionality without moving any parts and using already available components, but with a new configuration.

[0045] In some specific embodiments, the matrix arrangement includes at least 2,000 solid-state light sources.

[0046] This invention can be useful for many types of illumination matrix / array-based technologies, from the simplest technologies with only a few thousand light sources to more advanced technologies with hundreds of thousands of light sources.

[0047] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall be interpreted in accordance with their customary usage in the field. It will be further understood that terms of common usage shall also be interpreted in accordance with their customary usage in the relevant field, and shall not be interpreted in an idealized or overly formal sense unless expressly specified herein.

[0048] In this document, the term “comprises” and its derivatives (such as “comprising”, etc.) should not be understood in an exclusive sense, that is, these terms should not be interpreted as excluding the possibility that the content described and defined may include other elements, steps, etc.

[0049] To complete the specification and to better understand the invention, a set of accompanying drawings has been provided. These drawings form part of the specification and illustrate embodiments of the invention, which should not be construed as limiting the scope of the invention, but are merely examples of how the invention can be practiced. These drawings include the following figures:

[0050] [ Figure 1 A general perspective view of an automotive lighting device according to the present invention is shown.

[0051] [ Figure 2 The diagram illustrates some steps of the method according to the present invention.

[0052] [ Figure 3 The image shows a portion of the pixel matrix, which is related to... Figure 2 The numerical correspondence between light patterns and similar light patterns.

[0053] [ Figure 4 The diagram illustrates further steps of the method according to the invention.

[0054] [ Figure 5 The diagram illustrates some steps of the method according to the invention, corrected using some shift values. Figure 3 The matrix.

[0055] [ Figure 6 It shows Figure 5 The complete version of the light pattern, in which linear interpolation is performed between the boundary pixels of each row.

[0056] [ Figure 7 ]and[ Figure 8 This section illustrates different case studies involving turning right on a curve.

[0057] [ Figure 9 This demonstrates the effect of this shift in a more realistic light pattern.

[0058] [ Figure 10 It shows Figure 9 The first variant of the light pattern.

[0059] [ Figure 11 It shows Figure 9 The second variant of the light pattern.

[0060] Throughout the accompanying drawings and detailed embodiments, elements of the exemplary embodiments are consistently represented by the same reference numerals, where appropriate:

[0061] 1. Light pattern

[0062] 2 LED

[0063] 3. Control Center

[0064] 4 cameras

[0065] 5 light pattern lines

[0066] The first part of line 51

[0067] Part 2 of line 52

[0068] The central part of line 53

[0069] 6. Cutoff Line Area

[0070] 7 blank spaces

[0071] 8 boundary pixels

[0072] 10 Lighting equipment

[0073] 100 motor vehicles

[0074] The exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement and carry out the systems and methods described herein. It is important to understand that embodiments may be provided in many alternative forms and should not be construed as limited to the examples set forth herein.

[0075] Therefore, although the embodiments may be modified in various ways and take various alternative forms, specific embodiments thereof are shown in the accompanying drawings and are described in detail below as examples. There is no intention to limit oneself to the specific forms disclosed. Rather, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included.

[0076] Figure 1 A general perspective view of an automotive lighting device 10 according to the present invention is shown.

[0077] The lighting device 10 includes a matrix arrangement of LEDs 2 and a control center 3 configured to control the operation of these LED groups. The control center 3 is configured to modify the configuration of the LEDs 2 when the vehicle's steering wheel is activated.

[0078] Furthermore, the lighting device 10 includes a camera 4 to obtain an image of the road ahead, thereby obtaining the road outline.

[0079] This matrix configuration is a high-resolution module with a resolution greater than 1000 pixels. However, there are no restrictions on the technology used to produce the projection module.

[0080] A first example of this matrix configuration includes a monolithic source. This monolithic source comprises a matrix of monolithic electroluminescent elements arranged in columns and rows. In the monolithic matrix, the electroluminescent elements can be grown from a common substrate and electrically connected to selectively enable individually or by a subset of the electroluminescent elements. The substrate can be made primarily of semiconductor material. The substrate can include one or more other materials, such as non-semiconductors (metals and insulators). Thus, each electroluminescent element / group can form a light pixel and therefore emit light when its / their material is powered. This monolithic matrix configuration allows for the selectively enabled pixels to be arranged very close to each other, compared to conventional light-emitting diodes designed to be soldered onto a printed circuit board. The monolithic matrix can include electroluminescent elements whose main height dimension, measured perpendicular to the common substrate, is substantially equal to one micrometer.

[0081] A single matrix is ​​connected to a control center to control the generation and / or projection of pixelated beams emitted through the matrix arrangement. The control center is thus able to individually control the light emission of each pixel in the matrix arrangement.

[0082] As an alternative to the above-presented solution, the matrix arrangement may include a main light source coupled to the mirror matrix. Therefore, the pixelated light source is formed by an array of at least one main light source and a photoelectric element array (e.g., a micromirror matrix, also known as a "Digital Micro-mirror Device" acronym DMD), wherein the at least one main light source is formed by at least one light-emitting diode emitting light, and the photoelectric element array guides the light from the future autonomous light source to the projection optics by reflecting it. Where appropriate, auxiliary optics may collect the light from at least one light source to focus and guide it onto the surface of the micromirror array.

[0083] Each micromirror can pivot between two fixed positions: a first position and a second position. In the first position, light is reflected toward the projection optics; in the second position, light is reflected in a different direction than the projection optics. The two fixed positions are oriented in the same manner for all micromirrors and form a characteristic angle of the micromirror matrix relative to a reference plane supporting the matrix, as defined by its specifications. This angle is typically less than 20° and can be approximately 12°. Thus, each micromirror, reflecting a portion of the light beam incident on the micromirror matrix, forms the basic emitter of the pixelated light source. The actuation and control of the mirror position changes for selectively activating this basic emitter to emit or not emit the basic beam are controlled by a control center.

[0084] In various embodiments, the matrix arrangement may include a scanning laser system in which a laser source emits a laser beam toward a scanning element configured to probe a surface of a wavelength converter with the laser beam. An image of this surface is captured by projection optics.

[0085] The scanning element can be detected at a speed high enough that the human eye cannot perceive any displacement in the projected image.

[0086] Synchronous control of the illumination of the laser source and the scanning motion of the beam allows for the generation of a matrix of basic emitters, which can be selectively activated at the surface of the wavelength converter element. The scanning device can be a movable micromirror used to scan the surface of the wavelength converter element by reflection of the laser beam. Micromirrors mentioned as scanning devices are, for example, of the MEMS (“Micro-Electro-Mechanical Systems”) type. However, the invention is not limited to this type of scanning device, and other types of scanning devices can be used, such as a series of mirrors arranged on a rotating element, the rotation of which causes the transmission surface to be scanned by the laser beam.

[0087] In another variant, the light source can be composite and includes at least one segment of an optical element (such as a light-emitting diode) and a surface portion of a monolithic light source.

[0088] Figure 2 Some steps of the method according to the present invention are shown.

[0089] This diagram shows the initial low beam pattern 1. The low beam is divided into row groups 5, each row group containing one row of pixels.

[0090] Each light pixel 3 of the image pattern 1 is characterized by a number on a scale from 0 to 255, where 0 corresponds to no light and 255 corresponds to maximum luminous intensity.

[0091] Figure 3 A portion of the pixel matrix is ​​shown, which is similar to... Figure 2The image pattern 1 is represented by a numerical representation of the light patterns. Each light pixel in the image pattern 1 is characterized by a scale. The typical matrix uses a scale from 0 to 255, where 0 corresponds to no light and 255 corresponds to maximum luminous intensity.

[0092] In this image, the pixels are divided into rows of patterns 5. Each pattern includes a string of data, where the numbers are between 0 and 10, depending on the luminous intensity of the associated pixel. Clearly, these pixel values ​​are simplified examples chosen merely for better understanding of the invention and do not correspond to specific values. Figure 2 The luminous intensity of the light pattern.

[0093] Matrix arrangement provides resolution in terms of distance and angle. For example, in a matrix arrangement of 100 rows and 240 columns that can project light at 100 meters and cover an angle of 120°, the distance covered by each row is proportional to the height of the module and the tangent of the vertical angle covered by the corresponding row, and the angle covered by each column is 0.5° away from the previous column.

[0094] Since this example cannot cover such a large number of pixels, for clarity, Figure 3 The matrix contains 5 rows and 18 columns. While not entirely realistic, each row will be considered to cover a constant distance of 10m, and each column will be considered to cover a constant angle of 5°. Intensity values ​​will only range between 0 and 10.

[0095] Although the pattern in this figure does not correspond to the near-light pattern, it represents a region 6 that resembles a cutoff line, which has a diagonal set of values ​​that separates the dark and light parts.

[0096] Since this particular example will simulate a left turn, the first part 51 that will be shifted is the left-side portion and includes the cutoff line portion 6. The second part 52 is the remaining portion of the light pattern.

[0097] Figure 4 Further steps of the method are shown.

[0098] This diagram shows roads captured from cameras and / or GPS systems. Some road points RP1, RP2, RP3, RP4, and RP5 are calculated at different distances from the center point of the lane. The distances will depend on the row groups of the matrix arrangement. Continuing... Figure 3 For example, select road points at 10m, 20m, 30m, 40m, and 50m.

[0099] Each road point will define an angle of deviation relative to the main direction of the lighting fixture. These angles can be easily calculated from the 2D distance to the lighting fixture. Therefore, each road point is characterized by both distance and angle.

[0100] For example, road point 1RP1, which corresponds to a distance of 10m, has an angle of 5°; road point 2RP2, which corresponds to a distance of 20m, has an angle of 10°; road point 3RP3, which corresponds to a distance of 30m, has an angle of 20°; road point 4RP4, which corresponds to a distance of 40m, has an angle of 35°; and road point 5RP5, which corresponds to a distance of 50m, has an angle of 40°.

[0101] Using these values, the shift value for the first row will be 1 pixel, the shift value for the second row will be 2 pixels, the shift value for the third row will be 4 pixels, the shift value for the fourth row will be 7 pixels, and the shift value for the fifth row will be 8 pixels.

[0102] Figure 5 The correction using these shift values ​​is shown. Figure 3 The matrix is ​​used to shift each row to the left according to its corresponding shift value, thereby obtaining the modified light pattern.

[0103] However, this shift operation leaves a blank space of 7 in each row. Since each row has a different shift value, this blank space is different in each row.

[0104] The blank space is included between two boundary pixels of 8 pixels in each row. One boundary pixel corresponds to the last pixel of the first part of each row, and the other boundary pixel corresponds to the last pixel of the second part of each row. A blank space appears between these boundary pixels of 8 pixels, and this blank space is intended to be filled by the third part of each row.

[0105] Figure 6 A "complete" version of the light pattern is shown, in which linear interpolation is performed between the boundary pixels of each row.

[0106] During the upward movement, Figure 5 The distances between the eight blank pixels 7 between the boundary pixels 8 shown are filled in each row by a third portion 53. This third portion 53 is calculated as a linear interpolation between the intensity values ​​of the left boundary pixels and the intensity values ​​of the right boundary pixels.

[0107] Figure 7 and Figure 8 Different research cases assuming the curve is to the right are shown.

[0108] In this case, the division between the first and second parts in each row is different because the cutoff line is now in the right part, which becomes the first part, i.e., the part to be shifted.

[0109] As an example, the shift value for the first row will be 1 pixel, the shift value for the second row will be 2 pixels, the shift value for the third row will be 3 pixels, the shift value for the fourth row will be 3 pixels, and the shift value for the fifth row will be 5 pixels.

[0110] Through these values, and Figure 5 same, Figure 7 Some blank spaces are shown, which in this case become the third part. These blank spaces are... Figure 8 The filling is achieved through linear interpolation between boundary pixels.

[0111] Figure 9 This demonstrates the effect of this shift in a more realistic light pattern. The first part of each row is shifted according to different values, resulting in a final light pattern with better road adaptability than the light pattern provided by the current method.

[0112] However, as can be seen in the image, the upper portion of the light pattern may project some light onto the opposite lane. To provide a solution to this problem, the present invention offers different options.

[0113] Figure 10 The first option shown involves combining the invention with an adaptive driving beam feature to apply a dark mask to the portion of the beam to be projected onto the vehicle to avoid glare. In a simpler embodiment, the mask would simply be configured to prevent light from being projected onto the oncoming lane.

[0114] Figure 11 The second option is shown, in which the upper part of the light pattern is treated as a single line and thus shifted as a single line.

[0115] This option preserves the kink shape, preventing the opposite lane from being encroached upon by the deformed shape obtained in other embodiments of the method.

[0116] The lower part of the image will be divided into rows, as explained in the example above, but the upper part containing the kink of the near beam pattern will be treated as a single row, so that the shift value of all rows included in this global row will be the same.

Claims

1. A method for controlling a light pattern (1) provided by an automotive lighting device (10) of a motor vehicle (100), wherein, The light pattern (1) is provided by a matrix arrangement of light pixels (2), and the method includes the following steps: Provide road outlines; Extract road features from the road profile. The matrix is ​​arranged into row groups; Each row group is assigned a different shift value, and each shift value depends on the road features; Divide each row into a first part and a second part; The operation of the first part of each row group of the light source is shifted according to the corresponding shift value; Create a third part between the first part and the second part of the shift in each row group; The road features are road points, each road point being characterized by its distance from the lighting device and its angle from the lighting device, and the displacement value is calculated using the distance and angle of the road points; Each shift value is calculated using the distance and angle of at least one road point.

2. The method according to claim 1, wherein, Each row group corresponds to only one row of the matrix arrangement of light pixels.

3. The method according to claim 1, further comprising the step of applying correction to the luminous intensity of the light emitted by the light pixel (2).

4. The method according to claim 3, wherein, The correction includes a final mask configured to avoid glare, the final mask including dimming or turning off some of the shifted light pixels (2).

5. The method according to any one of claims 1-4, wherein, The third part (53) of each row group is an interpolation between a boundary pixel of the first part (51) and a boundary pixel of the second part (52).

6. The method according to claim 5, wherein, The interpolation is linear.

7. The method according to any one of claims 1-4, wherein, The light pattern (1) is a low beam pattern, and the first portion (51) includes the cutoff line of the low beam pattern.

8. The method according to any one of claims 1-4, wherein, The step of providing road outlines is performed using images from cameras.

9. The method according to any one of claims 1-4, wherein, The step of providing road outlines is performed using a global positioning system.

10. The method according to any one of claims 1-4, wherein, The light pixels of the light pattern are grayscale pixels.

11. The method according to claim 10, wherein, The luminous intensity of each pixel is based on a scale from 0 to 255.

12. An automotive lighting device (10), comprising: • A matrix arrangement of solid-state light sources designed to provide light patterns (1); • Road contour acquisition device (4); as well as • A control unit (3) for performing the steps of the method according to any one of claims 1-11.

13. The automotive lighting device according to claim 12, wherein, The matrix arrangement includes at least 2,000 solid-state light sources.

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