CZ309948B6 - Lighting device, in particular a signalling lamp for motor vehicles - Google Patents

Abstract

The lighting device, in particular a signalling lamp for motor vehicles, includes at least one light source (51) and a transparent light guide with a body (6) of the light guide, the surface of which includes an input area (62) for the launch of light generated by the light source (51) and the output front area (61), whereas the body (6) of the light guide has a surface which includes the input area (62) that is assigned to the light source (5) for the launch of light generated by the light unit (5), whereas the surface of the body (6) of the light guide further includes the output front area (61) and lateral areas (63). At least one of the areas (61, 62, 63) of the body (6) of the light guide is provided with a colour layer (64). The colour layer (64) has a colour which is different from at least one colour of the light emitted by the light sources (51), whereas the colour layer (64) has the thickness, shade and saturation when the colour of the light exiting the body (6) of the light guide with this light source (51) turned on and after the passage through the colour layer (64) meets the same colorimetric specification or is the same as the colour of the light emitted by this light source (51).

Description

Lighting equipment, in particular a signal lamp for motor vehicles

Field of technology

The invention relates to a lighting device, in particular a lamp for motor vehicles. The invention therefore falls into the field of construction of signal lamps, especially motor vehicles, and relates to a lighting device equipped with lighting units to ensure the achievement of various lighting functions.

Current state of the art

A lamp, especially for motor vehicles, contains several lighting units, where each of these lighting units ensures a different lighting function or contributes to ensuring the required emission characteristics of the light track. The individual lighting units are usually stored in a shaped carrying case of the lamp, while each unit contains at least one light source and other optical elements. The light source emits light rays, and the optical elements are a set of refracting and reflecting surfaces and interfaces of optical environments that influence the direction, intensity and frequency of the light rays when creating the output light trail. From the state of the art, a number of designs of rear signal lights for motor vehicles including a brake light, a rear marker light, a fog light, a reversing light and a turn signal light or indicator for changing the direction of travel are also known.

From the file EP 2161494, a design of a front signal lamp for motor vehicles adapted to provide various light functions such as daytime light, position light and direction light is known. The lighting device contains two different colored light sources, which are located on a common carrier. The light emanating from the light sources is connected to a light pipe equipped with an exit surface to ensure various light functions.

From the documents DE 20018905, DE 102012112076, EP 2792940, WO 2014135762, US 5711592, the design of light guides built into lighting devices is known. From the file US 2004047161, a design of a transparent colorless light pipe powered by light sources of the first color is known, which is provided with a color spray of the second color, and the light of the third color, which is a mixture of the first and second colors, emerges from the light pipe. This achieves the effect that the light guide in the extinguished state has a different color than the light emitted from it in the lit state. It is possible to achieve a significant color difference between the color of the light guide and the emitted light with this solution, but the disadvantage of this solution is the fact that the color of the light generated from the light sources is different from the color of the light emitted from the light guide. The change of light color from input to output is conditioned by the absorption of part of the input light spectrum. This reduces the intensity of the emitted light beam and also the efficiency of the entire optical system. Low efficiency results in the need to use stronger light sources, or a larger number of them, which increases the cost of manufacturing such lighting equipment. The solution described in DE 102012112151 also does not allow multiple light functions of different colors to be combined into one optical system. For example, the merging of the rear marker light and turn signal light is, however, desirable and often used in terms of saving space in the lamp body.

Laws of additive color composition can normally be formulated using the colorimetric triangle. Each color then corresponds to a point in the plane of the colorimetric triangle.

In the homologation regulations for the exterior lighting equipment of cars, the colorimetric triangle clearly defines the areas in which the colors of the individual lighting functions must be located.

A device with a light path is known from EP 2604914 A2: light source - input surface

-1 CZ 309948 B6 transparent light guide - transparent light guide body with reflective mirror - output surface of the transparent light guide arranged transversely to the input surface - color layer (optional second color layer) - light output from the lamp. The light source has any color and is emitted through the entrance surface into the light guide, which has a different color from the color of the light source. After the light passes through the colored layer, its color changes to a third color different from the first and the second.

From US 2016139328 AI, a device with a light path is known: light source - input surface of the light guide - homogeneous light guide designed as a frequency converter (+ optional polarizer), output surface of the homogeneous light guide arranged transversely to the input surface - color layer (another frequency changer). It also describes different implementations of an integrated cooler, since the frequency converter generates a lot of heat = energy losses = reduced performance.

From DE 102011055430 AI, a device with a light path is known: source - filter layer - input surface - ring light guide. The filter layer filters out wavelengths of 420 nm and shorter, to prevent degradation of the light guide. The filter layer can be arranged selectively only on a part of the input surface, so that it corresponds only to some (harmful) diodes of the source (paragraph 10).

The aim of the invention is to design a lighting device, in particular a signal lamp for motor vehicles, which can be adapted to the design requirements for the external appearance of the product. The solution according to the invention will allow the light guide of the lighting device to show a different color than the color of the emitted light when it is turned off. The light guide is advantageously installed in the lighting device in such a way that not only its front exit surface is visible, but also some of the side surfaces.

The essence of the invention

The above-mentioned objectives of the invention are met by a lighting device, in particular a signal lamp for motor vehicles, the essence of which is that the entrance surface or the exit front surface and at least one side surface of the light guide body are provided with a color layer, the color layer having a color that differs from at least one color of light emitted by the light sources, wherein the color layer has a thickness, hue and saturation in which the color of the light emerging from the body of the light guide when this light source is switched on and after passing through the color layer meets the same colorimetric specification or is the same as the color of the light emitted by this light source.

According to another advantageous embodiment, the surface of the light guide body includes two opposite side surfaces, at least one of which is provided with a colored layer.

According to another of the advantageous embodiments, the light unit contains at least one other light source, which emits light of the same color as the color of the color layer when switched on.

The body of the light guide and the color layer are preferably made in one piece.

The body of the light guide and the color layer preferably form an integral plastic part produced by multiple injection molding.

According to one of the advantageous embodiments, the light unit contains light sources of orange light and light sources of red light, and the color layer is made of red material.

According to another advantageous embodiment, the light unit contains light sources of white light and the color layer is made of light blue material.

According to one of the advantageous embodiments, the light unit contains light sources of light of two different colors arranged alternately next to each other.

-2 CZ 309948 B6

For purposes of this invention, description and claims, two colors are considered close to each other if both colors meet the same colorimetric specification. So, for example, the EHK regulation 48 lists four possible colors for exterior automotive lighting, which are white, selective yellow, orange and red. So, for example, if the light source meets the colorimetric specification for the color orange, we call the color of the light that exited the space outside the light guide close to the color of the light source's light, if this color also meets the colorimetric specification for the color orange.

Clarification of drawings

The invention will be further explained by means of its exemplary embodiments with reference to the accompanying drawings, in which it shows:

Fig. 1 is an axonometric view of an example of an embodiment of an optical assembly of a lighting device;

Fig. 2 is an axonometric view of another embodiment of the optical assembly of the lighting device;

Fig. 3 is an axonometric view of an example of a light water design;

Fig. 4 is a side view of the light guide from Fig. 3;

Fig. 5 is a top view of the light guide from Fig. 3;

Fig. 6 is a side view of the light guide with the paths of ambient light rays entering the light guide from the outside through the side surface shown; and Fig. 7 is a side view of possible arrangements of colored and colorless areas of the light guide.

Examples of implementation of the invention

According to Fig. 1, the lighting device contains a support case 1, which, together with a transparent front cover (not shown), forms the inner chamber 3 of the lamp, in which the lighting unit 5 is housed. 61 and one visible side surface 63. while the light guide from the frontal view creates a spatial design element. The output front surface 61 and the side surface 63 are provided with a colored layer 64.

According to Fig. 2, the lighting device includes a cover mask 4, which, together with a part of the light guide, forms the outer cover of the lighting device. The optical assembly includes a lighting unit 5 with light sources 51 and a surface-shaped light guide with a body 6 of the light guide. The body 6 of the light guide includes one output front surface 61 and four visible side surfaces 63. On the side facing the lighting unit 5, the body 6 of the light guide has a connecting input surface 62 for sending the light beam into the body 6 of the light guide towards the output front surface 61. Lighting unit 5 consists of two light sources 51 of different colors located on a carrier 22. for example on a printed circuit board. The color-different light sources 51 are preferably arranged alternately next to each other, so that the light of the first light function and the light of the second light function can be emitted over the entire output front surface 61 of the light guide. The light sources 51 of the lighting unit 5 preferably include light sources of yellow color and the remaining sources produce light beams of red color. The lighting unit 5 is connected to an unillustrated control unit, whereby light sources of two colors with different light functions are jointly and alternately controllable by the electronic control unit so that the electronic control unit turns on either the yellow color sources for the first light function or the red color sources for the second light function. A beam of light

-3 CZ 309948 B6 is primarily balanced by the output front surface 61. The output front surface 61 is provided with a color layer 64 of red color. At least one of the opposite side surfaces 63 is always provided with a red color layer 64.

Fig. 3, Fig. 4 and Fig. 5 show the design of the light guide with the body 6 of the light guide, whose output front surface 61 and two side surfaces 63 are externally provided with a colored layer 64. As regards the color of the light emitted by the light sources 51 and the color color layer 64, one preferred embodiment is an arrangement where the color layer 64 is red, some light sources 51 produce yellow light beams and other light sources 51 produce red light. Another preferred embodiment is an arrangement where the color layer 64 is light blue and the light sources 51 produce light beams of white color.

In Fig. 6, the view of the observer 7 on the side wall 63 of the body 6 of the light guide is shown through the optical paths of the rays 71. The rays 71 are rays of ambient light that enter the body 6 of the light guide from the outside first through the color layer 64 and then through the side surface 63 on which the color layer 64 is arranged. For a light guide with a rectangular cross-section made of a material with a refractive index n>1.41, it is generally true that all rays that come out of the side surface 63. enter the light guide through the opposite color layer 64, so they never enter through the entrance surface 62, nor the exit front surface 61.

The rays 71 entering the light guide through the lower color layer 64, which fall on the entrance surface 62 or the exit surface 61, are totally reflected back into the body 6 of the light guide and then exit the light guide through the side surface 63. Since all the rays exiting from the side surface 63 enter the light guide through the color surface 64, the side surface 63 appears to the observer 7 in color.

Fig. 7 shows examples of different arrangements of color layers 64 on the side surfaces 63 of the body 6 of the light guide.

In all the arrangements shown, even if not all surfaces 61, 62, 63 of the light guide are colored, the impression is created that the entire body of the light guide has the same color as the color of the colored layers 64. At first glance, it is not distinguishable for the observer which of the visible surfaces 61 , 63 is provided with a colored layer 64. and which surfaces 61, 62, 63 are colorless. Of the two pairs of mutually opposite side surfaces 63, in the examples shown, at least one is provided with a colored layer 64, and of the mutually opposite input and output surfaces 61, 62, exactly one is provided with a colored layer 64.

The light guide containing the transparent body 6 and the color layer 64 is preferably manufactured as a single plastic casting, preferably by a multiple injection method, where the color layer 64 is realized as a thin layer. In an alternative embodiment, the color layer 64 is produced either by a colored, additionally applied spray or coating applied to a transparent material. The light guide is provided with a colored layer 64, preferably especially on the visible surfaces 61, 63 of the light guide. The color layer 64 is chosen in such a thickness, shade and saturation that the light emerging from the light guide has a color close to the color of the light generated by the light sources 51.

For a given shade of color, it is always possible to achieve by thinning the color layer 64 or by diluting it, so that the color of the outgoing light meets the colorimetric specification, if it is met by the light generated by the light sources 51. This achieves the effect that the color of the light guide in the extinguished state is different from the color of the light from it emitted in the lit state. Thus, for example, when the color of the surface 61, 63 is red, and the color of the light beam emanating from the light sources 51 is yellow, the light passing through the colored layer 64 is still yellow.

Claims (8)

1. A lighting device, in particular a signal lamp for motor vehicles, comprising a light unit (5) with at least one light source (51) and further comprising a transparent light guide with a body (6) of the light guide, wherein the body (6) of the light guide has a surface that includes an input a surface (62) which is assigned to the light unit (5) for connecting the light generated by the light unit (5), wherein the surface of the body (6) of the light guide further includes an exit front surface (61) for the output of the light generated by the light unit (5) and further comprises side surfaces (63), while at least one of the surfaces (61, 62, 63) of the body (6) of the light guide is provided with a color layer (64), characterized in that the input surface (62) or output surface (64) is provided with the color layer (64) front surface (61) and at least one side surface (63) of the body (6) of the light guide, wherein the color layer (64) has a color that differs from at least one color of the light emitted by the light sources (51), wherein the color layer (64) has the thickness, hue and saturation at which the color of the light emerging from the body (6) of the light guide when this light source (51) is switched on and after passing through the color layer (64) meets the same colorimetric specification or is the same as the color of the light emitted by this light source (51 ). 2. Lighting device according to claim 1 or 2, characterized in that the surface of the body (6) of the light guide includes two opposite side surfaces (63), at least one of which is provided with a colored layer (64). 3. A lighting device according to any one of the preceding claims, characterized in that the lighting unit (5) contains at least one additional light source (51), which emits light of a color such as the color of the color layer (64) when switched on. 4. Lighting device according to any one of the preceding claims, characterized in that the body (6) of the light guide and the colored layer (64) are made in one piece. 5. Lighting device according to claim 4, characterized in that the body (6) of the light guide and the colored layer (64) form an integral plastic part produced by multiple injection molding. 6. Lighting device according to any one of the preceding claims, characterized in that the lighting unit (5) contains light sources (51) of orange light and light sources (51) of red light and the color layer (64) is made of a red material. 7. Lighting device according to any one of the preceding claims, characterized in that the lighting unit (5) contains light sources (51) of white light and the color layer (64) is made of light blue material. 8. Lighting device according to any one of the preceding claims, characterized in that the lighting unit (5) contains light sources (51) of light of two different colors arranged alternately next to each other.