Patent Description:
It is known from the prior art that by means of a projection headlight in a motor vehicle a warning symbol can be projected onto the roadway in the principle of a slide projector. For this purpose, a graphic printed on a (plastic) slide is imaged using a projection lens. In order to achieve efficient illumination of the slide, a condenser lens is inserted between the light source and the slide. The slide is arranged between the condenser lens and the projection lens as an independent component. Such a projection headlight is shown in <FIG> and <FIG>. The projection headlight (<NUM>) comprises at least one light source (<NUM>), a projection lens (<NUM>), a condenser lens (<NUM>) arranged between the at least one light source (<NUM>) and the projection lens (<NUM>). The condenser lens (<NUM>) is having a flat side (<NUM>) and a curved side (<NUM>). The projection headlight (<NUM>) further comprises a slide (<NUM>) with a printed graphic (<NUM>). The slide (<NUM>) is arranged between the condenser lens (<NUM>) and the projection lens (<NUM>). The slide (<NUM>) is spaced to the condenser lens (<NUM>) with a certain distance.

The disadvantage of such a projection headlight is that it is not cost effective and is not very efficient due to light losses at the surfaces of the slide. Because of the arrangement of the slide between the condenser lens and the projection lens the emitted beams of the light source of the projection headlight have to pass through the surfaces of the slide. This causes light losses within the projection headlight.

<CIT> discloses to a lighting device for vehicles with a housing, the front opening of which is covered by a lens. At least one section of the lens has a smooth inside and outside. A light element and a component, which is provided with an identification mark are arranged in the interior of the housing. The identification mark is visible through a section of the light disk that has a smooth outside and inside.

<CIT> shows a lighting device for a motor vehicle with at least one light source, the light emission of which provides a light function for the motor vehicle, and with at least one reflector, the lighting device is designed in such a way that a roadway is illuminated or can be illuminated with a light pattern. At least one illuminant for generating the light pattern is arranged behind the at least one reflector in the light exit direction.

<CIT> discloses a warning device for an industrial truck, which, arranged on the industrial truck, projects a pictorial information symbol, in particular a pictorial warning symbol, onto a roadway. The warning device being designed as a projector which emits a light source that emits a luminous flux, and an image template of the information symbol to be projected, which can be transilluminated by the luminous flux generated by the light source. In the projector the original image has at least one area which is transparent to the luminous flux of the light source and an area that shades the luminous flux of the light source, and the projector has a free-form lens arranged between the light source and the original image, the free-form lens being designed in such a way that the luminous flux of the light source is incident on the translucent area of the original image is bundled.

<CIT> discloses a multifunction assembly comprised of: an outer surface structure containing a side door that supports at least one exterior mirror assembly, an exterior door handle assembly of said door, and an exterior laser emitter which emits a fixed and direct line of laser light downwards on said ground adjacent to the vehicle, indicating an area where the doors open and combines functions associated with other indicator signal devices, sensors and open door commands, and an ultraviolet light emitter device.

<CIT> discloses an optical device comprising a first surface with a plurality of micro sized facets, each facet having a respective orientation. Said plurality of facets having an optical axis, which extends parallel to the normal vector to an average orientation of all said respective orientations. The plurality of facets comprising at least a first and a second group of facets, each group is formed by a respective number of at least twenty-five compactly arranged neighboring facets. Each group is arranged to generate during operation a respective, mutually identical whole pattern. Each facet in a respective group is arranged to display a sub-pattern of said respective whole pattern. The whole patterns are mutually superpositioned.

The object of the present invention is to provide a projection headlight for a vehicle, in particular for a motor vehicle, which at least partially avoids the previously described disadvantages. Particularly, it is the object of the present invention to provide a projection headlight for a vehicle, in particular for a motor vehicle, which is economical, which is small in size and which is efficient due to lower light losses. Aforesaid problem is solved by a projection headlight with the features of claim <NUM> and by a vehicle with the features of claim <NUM>.

Features and details of the present invention result from the subclaims, the description and the respective drawings. Features and details discussed with respect to the inventive projection headlight are also related to features and details discussed with respect to the vehicle and vice versa.

According to a first aspect of the invention the problem is solved by a projection headlight for a vehicle, comprising at least one light source, a projection lens, a condenser lens arranged between the at least one light source and the projection lens. The condenser lens is having a flat side and a curved side. The projection headlight further comprises at least one printed graphic arranged between the condenser lens and the projection lens. The at least one printed graphic is printed on the flat side of the condenser lens.

That means, the graphic to be imaged onto the roadway is printed directly on the flat surface of the condenser lens. The printing can be done in digital printing, screen printing or in particular in pad printing. However, the graphic can also be a coating, for example a colored coating with pigments or dyes and interference coatings, into which the graphic to be generated is introduced by ablation processes, for example removal by means of laser. No additional slide is needed. This saves costs. Advantageously there is no distance between the graphic and the condenser lens. Furthermore, the projection headlight is more efficient due to lower light losses, since the elimination of the slide eliminates two interfaces at the transition between air and (plastic) slide. In addition, the size of the projection headlight can be reduced by the omission of a component.

The projection headlight can comprise only one light source. Advantageously the projection headlight comprises several light sources, which can all be the same design. The projection headlight may have a housing in which the individual components are arranged.

Preferred is a projection headlight, wherein a collimator is arranged in front of each light source. That means, each light source has its own collimator which is used to generate light with a parallel or an approximately parallel beam path from each light source in direction to the condenser lens.

Preferred is a projection headlight, wherein the flat side of the condenser lens faces the projection lens and the curved side of the condenser lens faces the light source. For this purpose, the condenser lens is rotated in contrast to the location of the condenser lens of the projection headlight according to the prior art shown in <FIG>.

The condenser lens is rotated in the existing product by <NUM> ° and moved to the correct focus position with respect to the desired image. Such an arrangement of the condenser lens in the projection headlight allows that the graphic is located in the beam path of the light of the light source behind the condenser lens.

The light source can be any type of light sources. Preferred is a projection headlight, wherein the at least one light source is a light-emitting diode (LED). In particular, a projection headlight is preferred, which has a plurality of LEDs.

The at least one light source can be arranged at a circuit board. Further, the circuit board and therefore the at least one light source can be arranged at a heatsink. This allows efficient cooling of the LEDs.

Preferred is a projection headlight, wherein the printed graphic is a warning symbol or a traffic sign. Such a projection headlight allows imaging the warning symbol or a traffic sign onto the roadway. Hereby, a driver of a vehicle can be easily and quickly notified of dangerous situations.

A projection headlight is preferred, which has an adjustment mechanism for adjusting the position of the projection headlight relative to the vehicle. As a result, the position or distance of the projected graphic in front of the vehicle can be adjusted.

According to a second aspect of the invention the problem is solved by a vehicle having at least one projection headlight, wherein the at least one projection headlight is a projection headlight according to the first aspect of the invention.

Therefore, the vehicle according to the invention can offer the same advantages as those described for the projection headlight according to the invention.

A vehicle, in particular a motor vehicle, can comprise at least one projection headlight. Preferred is a vehicle, in particular a motor vehicle, which has two or more projection headlights according to the first aspect of the invention. Such a vehicle allows a driver to project a warning symbol in front of the vehicle onto the road during a driving situation to indicate a danger or an obstacle.

The projection headlight is positioned as a whole in an opening of a body part of the vehicle. The appearance of the projection headlight is thus characterized by the arrangement of the light sources and the lenses.

In the following, preferred embodiments of the invention are described based on supportive figures. Thereby, the features described in the claims and in the description can be each single or in every combination essential for the invention. Elements bearing the same function and mode of action are assigned to the same reference signs. It is shown schematically:.

<FIG> shows a schematic representation of a projection headlight <NUM> of a motor vehicle according to the prior art. In <FIG> the beam path of the light source <NUM> of the projection headlight <NUM> according to <FIG> is shown.

<FIG> shows a schematic representation of a projection headlight <NUM> of a motor vehicle <NUM> according to the invention. The projection headlight <NUM> comprises several light sources <NUM>, a projection lens <NUM> and a condenser lens <NUM> arranged between the light sources <NUM> and the projection lens <NUM>. In front of each light source a collimator <NUM> is arranged. The collimator <NUM> is used to generate light with a parallel or an approximately parallel beam path from each light source <NUM> in direction to the condenser lens <NUM>. The condenser lens <NUM> comprises a flat side <NUM> and a curved side <NUM>. Further, the projection headlight <NUM> comprises a printed graphic <NUM>, which is printed on the flat side <NUM> of the condenser lens <NUM>. In contrast to the arrangement of the printed graphic <NUM> at the slide <NUM>, as shown in the projection headlight <NUM> of <FIG> and <FIG> according to the prior art, the projection headlight <NUM> according to the invention does not have a slide. The printed graphic <NUM> is printed directly onto the surface of the flat side <NUM> of the condenser lens <NUM>. That means, the graphic <NUM> to be imaged onto the roadway <NUM>, see <FIG>, is printed directly on the flat surface of the condenser lens <NUM>. No additional slide is needed. This saves costs and space. The size of the projection headlight <NUM> can be reduced by the omission of a slide. The projection headlight <NUM> can be produced with smaller dimensions in contrast to a projection headlight <NUM> according to the prior art shown in <FIG> and <FIG>. Advantageously there is no distance between the printed graphic <NUM> and the condenser lens <NUM>. Furthermore, the projection headlight <NUM> is more efficient due to lower light losses, since the elimination of the slide eliminates two interfaces at the transition between air and (plastic) slide.

It is possible to arrange two or more printed graphics <NUM> on the flat surface <NUM> of the condenser lens <NUM>, see <FIG>.

In <FIG> a schematic representation of another projection headlight <NUM> of a motor vehicle <NUM> according to the invention is shown. In contrast to the projection headlight <NUM> shown in <FIG> the projection headlight <NUM> shown in <FIG> has only one light source <NUM>. Further, a beam path <NUM> of the light source <NUM> of the projection headlight <NUM> is disclosed. The light beam <NUM> emitted by the light source <NUM> passes through the collimator <NUM> which is arranged between the condenser lens <NUM> and the light source <NUM>. The collimator <NUM> generates a parallel or an approximately parallel beam path in direction to the condenser lens <NUM>. The light beam <NUM> passes through the condenser lens <NUM> and then immediately the printed graphic <NUM> on the flat side <NUM> of the condenser lens <NUM>. After passing the printed graphic <NUM> the light beam <NUM> passes the projection lens <NUM> which projects the printed graphic <NUM> onto the roadway <NUM> in front of a vehicle in which the projection headlight <NUM> is arranged.

The light sources <NUM> of the projection headlight <NUM> are advantageously light-emitting diodes (LED). The light sources <NUM> can be arranged at a circuit board <NUM> of the projection headlight <NUM>. The circuit board <NUM> can be flexible. Further, the circuit board <NUM> and therefore the at least one light source <NUM> can be arranged at a heatsink <NUM>. This allows efficient cooling of the at least one light source <NUM>.

The printed graphic <NUM> can be a warning symbol or a traffic sign. The projection headlight <NUM> allows imaging such a warning symbol or a traffic sign onto the roadway <NUM> in front of the vehicle <NUM>, see <FIG>. The driver of the vehicle <NUM> can be easily and quickly notified of dangerous situations by imaging the warning symbol or a traffic sign onto the roadway <NUM>.

The projection headlight <NUM> and/or the vehicle <NUM> can comprise an adjustment mechanism for adjusting the position of the projection headlight <NUM> relative to the vehicle <NUM>. As a result, the position or distance of the projected graphic <NUM> in front of the vehicle <NUM> can be adjusted.

Claim 1:
Projection headlight (<NUM>) for a vehicle (<NUM>), comprising at least one light source (<NUM>), a projection lens (<NUM>), a condenser lens (<NUM>) arranged between the at least one light source (<NUM>) and the projection lens (<NUM>), the condenser lens (<NUM>) having a flat side (<NUM>) and a curved side (<NUM>), and comprising at least one printed graphic (<NUM>) arranged between the condenser lens (<NUM>) and the projection lens (<NUM>),
characterised in
that the at least one printed graphic (<NUM>) is printed on the flat side (<NUM>) of the condenser lens (<NUM>).