The invention relates to a signal light device of a motor vehicle designed to fulfil one or more signal light functions, such as brake light, tail light, daytime running light, direction indication light etc., comprising at least one signal lighting unit.
New vehicle lighting systems do not only focus on the optical output increasing the driving comfort and traffic safety, but it is also the appearance that is important for modern light devices of motor vehicles as headlights or signal lamps of a motor vehicle. Modern point and planar light sources, especially LED and OLED sources, have opened a new chapter for new stylistic options of car designers.
Using a planar light source, especially OLED—Organic Light Emitting Diodes—brings not only an extension of designer possibilities of the emitted light function, but it is also characterized by certain technical benefits including e.g. compact installation dimensions, low heat production, low energy consumption etc. Unfortunately, there are still some limitations of the OLED technology preventing widespread deployment of this technology in the serial production of car lighting. E.g. service life, penetration of moisture, low luminance for power functions, limitation to planar surfaces only and last, but not least, a high price. Another drawback of the OLED technology is the fact that a lamp of a motor vehicle must be adapted do detect an error status of the light source. With conventional LED's, this condition can be detected relatively well because in most cases, a short circuit or diode disconnection occurs, which results in a change of an electric quantity that can be relatively easily electronically detected. The situation of planar sources is more complicated because OLED's comprise organic layers that emit light after connection of electric voltage/current.
The documents WO2010058625A1, U.S. Pat. Nos. 9,684,111B2, 9,625,641B2, 9,039,244B2, 8,801,208B2, 8,430,519B2, 7,663,804B2, 7,651,241B2, 7,188,988B2, US20100315817A1, US20100110330A1, US20100079980A1, US20070147073A1, US20060262564A1, US20060114690A1, JP05951391B2, JP05816908B2 disclose a great number of solutions using a planarly shaped lighting unit equipped with an output surface for the output of light rays wherein there is an effort to achieve a homogeneous appearance or to achieve the required light effect on the output surface while the objective is fulfilled by means of a point or linear source and an assembly of optical components associated with the light-guiding body. The disadvantage of the above-mentioned design solutions is that these lighting units are not intended to be used as external lighting equipment for motor vehicles, for which a variety of technical specifications and regulatory requirements must be met on the one hand, but there are also requirements for the size of the installation space, low manufacturing and assembly costs of such devices.
To achieve the highest possible efficiency of light devices, efficient binding of light rays to light-guiding components must be ensured. Individual optical elements as a system of refractive and reflective surfaces and interfaces of optical environments must be arranged in such a way to prevent light losses to the highest possible extent, and at the same time to create an output light trace with the required light characteristic, i.e. the required light intensity and homogeneous appearance with constant luminance all over the output surface.
Car lighting has certain specific features as it is not only the appearance and the total luminance of the lighting function that is concerned. Individual lighting functions must conform to locally valid legislative regulations (e.g. ECE, SAE, CCC etc.). Each function has different requirements for the minimal and maximal luminous intensity values at certain angles. This means that the purpose is not only to emit a certain amount of light from lighting elements. It is also necessary to emit light having certain luminous intensity at individual angles specified by the legislation. This luminous intensity is based on the minimum and maximum values in individual regulations for individual angles. A lighting function should be preferably designed in such a way to meet requirements of as many regulations as possible. So there is a certain overlap of the intervals of the specified minimum and maximum values for individual angles. In this case, a lamp or headlight can be used for more markets at the same time without changes. However, there are cases when the requirements of all regulations cannot be met with the use of a single design of a lighting function. In that case, the lighting function must be adapted to the requirements of individual markets, which results in a unique product for the particular market.
The document CZ20190176, CZ20180107 disclose design solutions using a planarly shaped lighting unit equipped with an output surface for the output of light rays wherein these lighting units are adapted to be used in lighting devices of motor vehicles. Lighting units consists of a planar light guide with an associated light source arranged at a lateral side. Binding light to the light guide from a lateral side brings installation complications as the light source must be covered with a covering mask at the edge of lighting unit. Also, these solutions exhibit a problem concerning homogeneous illumination of the output surface in case of a low design of the lighting device while this arrangement of optical components makes the use of a segmented light module with multiple independent segments/sectors impossible.
The above-mentioned drawbacks are mitigated or removed by a signal light device of a motor vehicle designed to fulfil one or more signal light functions according to the invention, comprising a housing covered by transparent or translucent cover which separates and protects the signal light device from external surroundings of the motor vehicle, the internal chamber delimited by the housing and the cover and comprising at least one signal lighting unit, wherein the lighting unit comprises:
In one preferred embodiment, the thickness of the thin-walled partition panel is less than or equal to 2.5 mm.
The cover may be plate-like shaped and be planar or curved, and the front panel may be planar or curved.
The front panel may be approximately parallel to an opposing part of the cover.
The thin-walled partition panel is preferably optical foil.
In one of preferred embodiments, the thin-walled partition panel, the main reflective surface and the front panel are approximately parallel.
Preferably, the distance between the main reflective surface and the thin-walled partition panel is 0.5 mm to 5.0 mm and the distance between the thin-walled partition panel and the front panel is between 0.5 mm and 5 mm.
The carrier is preferably of a plate-like shape, so in such a case, the signal lighting unit also has a plate-like shape wherein the thickness of the signal lighting unit is preferably from 2 mm to 12 mm.
In one of preferred embodiments, the signal lighting unit further comprises a lateral cover that closes the signal lighting unit at a side.
The inner walls of the lateral cover may be fitted with lateral reflective surfaces to reflect light rays.
The main reflective surface may for instance consist of a layer applied on the supporting surface carrier as a white colour coat.
In one of preferred embodiments, the optical axis of the beam of light rays emitted from the light source is perpendicular to the thin-walled partition panel and the reflective surface.
In another preferred embodiment, the signal light unit comprises at least two light sources carried by a common carrier. The light sources may be arranged on the carrier with gaps next to each other in the direction of the longitudinal axis of the signal lighting unit.
The signal lighting unit according to the invention preferentially uses a light source(s) of the LED type.
In one of preferred embodiments, the focal point of the light sources of the LED type is situated at a distance of 0.5 mm to 5 mm from the thin-walled partition panel.
The carrier in the signal lighting unit is preferably a PCB.
In one of preferred embodiments, the thin-walled partition panel comprises several parts arranged next to each other in the direction of the longitudinal axis of the signal lighting unit and the lateral cover is structured to embed individual parts of the thin-walled partition panel in the lateral cover to enhance rigidity of the overall structure of the signal lighting unit.
The present invention will be further clarified in more detail with the use of its embodiment examples referring to the enclosed drawings wherein:
A signal light device 1 comprises a housing la covered by transparent or translucent cover 2 which separates and protects the signal light device 1 from external surroundings of the motor vehicle, the inner chamber 4 delimited by the housing la and the cover 2 and comprising at least one signal lighting unit 3. The signal light device 1 is designed to be built in the car body, and therefore, the cover 2 is in most applications curved to fit structurally or aesthetically to a shape of surrounding car body. Since the cover protects the interior of the signal light device 1 from dust, particles, water mud, etc. also during car driving, it must fulfil relevant prescriptions as to its physical and material properties such as crack strengths and also requirements for a way it permanently deforms in case of car accidents to reduce the danger of fragments to people.
The signal light device 1 comprises in the inner chamber 4 a lighting unit 3 that is secured to the housing 1a.
The lighting unit 3 comprises:
The thin-walled partition panel 12 comprises an input surface 20 facing the supporting surface 22 and an output surface 21 opposite the input surface 20. The supporting surface 22 is fitted with the main reflective surface 11 to reflect light rays 10. The space between the front panel 7 and the output surface 21 and between the supporting surface 22 with the said at least one light source 6 and the input surface 20 is only filled with air.
For each light source 6, the thin-walled partition panel 12 is, in the region situated opposite the light source 6, fitted on its input surface 20 with the first arrangement 24 of the first reflective surfaces 12a and the first gaps 12c between the first reflective surfaces 12a, and on its output surface 21 with the second arrangement 25 of the second reflective surfaces 12b and the second gaps 12d between the second reflective surfaces 12b. The first and second reflective surfaces 12a, 12b are configured to reflect light rays 10 and the first and second gaps 12c, 12d are configured to transmit light rays 10. The said first arrangement 24 and the second arrangement 25 are configured to achieve a pre-determined intensity distribution of the output of light rays 10 from individual places of the output surface 21 of the thin-walled partition panel 12. The lighting unit 3 is terminated with a front frame 16 at the front. The purpose of the frame 16 is generally aesthetical but the frame 16 also can serve to strengthen the structure, hide some parts that are not to be seen from outside the car etc.
The front panel 7 preferably consists of several optical foil sheets stacked on each other, as will be described with reference to other embodiments of the invention. The supporting surface 22 of the carrier 5 is fitted with a reflective surface 11 that may be continuous and cover the whole supporting surface 22 except the place where the light source 6 is situated. The focal point of the light source 6, which is preferably a LED type source, is situated in the immediate vicinity of the thin-walled partition panel 12, preferably at a distance from 0.5 mm to 5 mm from the thin-walled partition panel 12.
As indicated by the preferred embodiment of
Thus, in the preferred embodiment of
This invention assumes that the term “panel” (front panel 7, thin-walled partition panel 12) comprises both “planar” panels (i.e. panels with two planar opposite largest surfaces), and curved panels—bent or corrugated (i.e. panels with two curved opposite largest surfaces).
The reflective surface 11 may be created in such a way that it is the entire supporting surface 22 of the carrier 5 adapted to exhibit excellent reflective characteristics. Alternatively, the reflective surface 11 may be produced by application of a highly reflective layer on the supporting surface 22 of the carrier 5, application of white colour coating etc. Preferably, the inner surface of the lateral cover 8, i.e. surface facing the inner chamber 9 is also fitted with a lateral reflective surface 23, which may be produced similarly to the reflective surface 11 of the carrier 5. The reflective surface 11 of the carrier 5 is used to reflect light rays 10 that have been generated by the light source 6 and fallen on the reflective surface 11. Alternatively, the reflective surface 11, and possibly also the lateral reflective surface 23, may be adapted to diffusion reflection of light rays 10.
Thus, all along the width of the lighting unit 3, there is continuous reflection of light rays 10 emitted by the light source 6, which is advantageously a LED type source, and partial transmission of light rays 10 through the thin-walled partition panel 12. The mutual arrangement of the first reflective surfaces 12a and the second reflective surfaces 12b, their size, distribution on the input surface 20 and output surface 21 of the thin-walled partition panel 12 and location of the first reflective surfaces 12a with respect to the second reflective surface 12b and to the light source 6 can be used to influence the distribution of the output of light rays 10 from individual places of the output surface as well as the direction of their output 21 to a certain extent. This means that a suitable arrangement of the first and second reflective surface 12a, 12b with respect to each other and the light source 6 and the selection of their suitable size can be used to achieve a pre-determined distribution of intensity of the said output of light rays 10.
The other figures show examples of the first arrangement 24 of the first reflective surfaces 12a and the first gaps 12c as well as an example of the second arrangement 25 of the second reflective surfaces 12b and second gaps 12d in particular patterns configured with the intention to achieve a uniform—homogeneous output of light rays 10 from the output surface 21 of the thin-walled partition panel 12.
As regards the second reflective surfaces 12b and the second gaps 12b between them, which the output surface 21 of the thin-walled partition panel 12 is fitted with, they are organized in the second arrangement that may be identical to the first arrangement, i.e. the arrangement of the first reflective surfaces 12a and the first gaps 12c on the opposite input surface 20 of the thin-walled partition panel 12. Here, the first arrangement—pattern of the first reflective surfaces 12a may be positioned exactly in alignment with the identical second arrangement—pattern of the second reflective surfaces 12b, or the first arrangement and the second arrangement may be positioned with a mutual offset/shift as such an embodiment example is shown in
Thus, the inventive solution makes it possible to use the selection of the first arrangement, i.e. arrangement of the patterns of the first reflective surfaces 12a and the first gaps 12c on the input surface 20, and the second arrangement, i.e. arrangement of the second reflective surfaces 12b and the second gaps 12d on the output surface 21, and the mutual positioning of the first and second arrangements 24, 25, to control the passage of light through the thin-walled partition panel 12—preferably foil to influence homogeneity of the optical system.
1—signal light device
1a—housing
2—cover
3—signal lighting unit
4—inner chamber
5—carrier
6—light source
7—front panel
8—lateral cover
9—chamber
10—light ray
11—main reflective surface
12—thin-walled partition panel
2012a—first reflective surface
12b—second reflective surface
12c—first gap
12d—second gap
13—diffusion layer
14—first functional layer
15—second functional layer
16—front frame
17—first ray
18—second ray
19—third ray
20—input surface
21—output surface
22—supporting surface
23—lateral reflective surface
24—first arrangement
25—second arrangement
p—longitudinal axis of the lighting unit
x—optical axis of the beam of light rays
Number | Date | Country | Kind |
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PV 2020-344 | Jun 2020 | CZ | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CZ2021/000023 | 6/4/2021 | WO |