Automotive comfort projection device

Abstract

Motor vehicle comfort projection device (10), comprising a light source (12) and a projection lens (20), wherein the motor vehicle comfort projection device (10) comprises a conical light guide (14), a converging lens serving as a field lens (16), and a liquid crystal matrix display (18) as an imaging element, and a projection lens (20) configured for imaging the liquid crystal matrix display (18), characterized in that the light source (12) comprises light-emitting diodes (12.i) with at least two different light colors, that the field lens (16) is a Fresnel lens (16.1), and that Fresnel zones of the Fresnel lens (16.1) point in the direction of the incident light.

Description

[0001] The present invention relates to a motor vehicle comfort projection device according to the preamble of claim 1. Such a device is known from DE 102 15 893 C1.

[0002] The spread of digital technology in vehicles means that even functions established over decades, such as vehicle interior lighting, will be controlled adaptively and without contact in the future.

[0003] This is not just about adapting the lighting area of ​​the passenger compartment to the passenger's wishes in terms of shape, size and color temperature across a wide range; the projection of welcome animations and display functions should also contribute to improving the interaction between passenger and vehicle and creating a pleasant and comfortable atmosphere for the traveler in every respect.

[0004] Various forms of video projectors using LCD (Liquid Crystal Display) and DLP (Digital Light Processing) technology are known from the current state of the art. However, due to system costs and miniaturization possibilities, these are hardly suitable for use as digital comfort lighting in motor vehicles. While LCD projectors are superior to DLP systems suitable for automotive applications in terms of system costs, the effort required for color projection is still considerable, as separate light beam paths are typically required for each primary color, which are then combined using dichroic mirrors.

[0005] A further simplification would be the use of color LCD displays, which provide pixels with corresponding color filters for each primary color and only require white backlighting. However, these color filters result in high power losses, which is why such projectors are not only inefficient and dim, but also suffer from high self-heating of the LCD display, which is difficult to passively cool and severely limits the operating range of the system.

[0006] Against this background, the object of the invention is to provide a motor vehicle comfort projection device that can variably illuminate a desired illumination area in terms of shape, size and color temperature as a color video projection system.

[0007] The device should have a very broadband light source to ensure good color rendering. To replace conventional reading lamps, the device must be highly miniaturized, highly efficient, and also inexpensive.

[0008] These requirements are met by the sum of the features of claim 1.

[0009] The present invention differs from the prior art mentioned at the outset in that the projection device comprises a conical light guide, a converging lens serving as a field lens, a liquid crystal matrix display as an imaging element and a projection lens designed to image the liquid crystal display.

[0010] The automotive comfort projection device according to the invention is suitable as a digitally controllable interior lighting device for motor vehicles. However, the automotive comfort projection device according to the invention can also be configured to project moving images into a lighting zone located outside the motor vehicle, for example, to greet the driver (Welcome Carpet) upon approaching the vehicle, etc. Due to its small size, the automotive comfort projection device can be easily integrated into a door or even an exterior mirror of the motor vehicle. Compared to multi-LED solutions, the automotive comfort projection device according to the invention offers significantly better image quality with considerably higher color rendering values ​​and the ability to project color videos.The described liquid crystal projector can be manufactured particularly cost-effectively (cost-effective display, relatively few components).

[0011] A preferred embodiment is characterized by the fact that the light source has LEDs with at least two different light colors.

[0012] It is also preferred that the light colors are cool white and yellow. It is further preferred that the light colors are blue, red, and green. Another preferred embodiment is characterized by the fact that the light colors are blue, red, green, and white.

[0013] It is also preferred that the light colors are additionally yellow and / or orange and / or cyan and / or violet.

[0014] Furthermore, it is preferred that blue light-emitting LED chips are used to generate the different colors, the light of which is converted into the respective colors by corresponding phosphor layers.

[0015] Another preferred design is characterized by the fact that the LEDs can be controlled independently or separately according to color.

[0016] It is also preferred that the conical light guide is a truncated pyramid.

[0017] Another preferred embodiment is characterized by the fact that the cross-section of the optical fiber lying perpendicular to the main propagation direction in the optical fiber is rectangular or square.

[0018] It is also preferred that the light guide is made of glass, in particular of an inorganic crown glass.

[0019] Furthermore, it is preferred that the light entry and light exit surfaces of the light guide are parallel to each other.

[0020] Another preferred embodiment is characterized by the fact that the length of the light guide in the main propagation direction of the light is 2 to 8 times the diagonal of the light-emitting surface of the light guide.

[0021] It is also preferred that the corresponding side lengths of the light entry surface and the light exit surface differ by an integer factor, where the factor can have values ​​from 2 to 8 and the light exit side is longer than the corresponding light entry side.

[0022] It is further preferred that the optical fiber has two planes of symmetry which contain the optical axis and which are each perpendicular to two side surfaces and to the light entry surface and the light exit surface.

[0023] Another preferred embodiment is characterized by the fact that the light entry surface and the light exit surface of the light guide are coated with an anti-reflective coating.

[0024] It is also preferred that the field lens is arranged upstream of the liquid crystal display, directly in front of the liquid crystal display, between the light guide and the liquid crystal display.

[0025] Another preferred embodiment is characterized by the fact that the field lens is arranged directly downstream of the liquid crystal display, between the display and the projection lens.

[0026] It is also preferred that the field lens be a Fresnel lens.

[0027] It is further preferred that the Fresnel zones of the Fresnel lens point in the direction of the incident light. The Fresnel zones (or Fresnel surfaces) are areas on a non-smooth light-entry surface of the Fresnel lens. Another preferred embodiment is characterized in that the Fresnel surfaces are conical surfaces, spherical surfaces, or aspherical surfaces with a common axis of rotation.

[0028] It is also preferred that the Fresnel lens be made of glass, in particular of organic glass.

[0029] It is further preferred that the Fresnel lens consists of PMMA (polymethyl methacrylate), PC (polycarbonate), PEI (polyetherimide), COC (cyclo-olefin copolymer) or COP (cyclo-olefin polymer).

[0030] Another preferred embodiment is characterized by the fact that the focal length of the field lens is greater than or equal to the focal length of the projection lens.

[0031] It is also preferred that the optical surfaces of the field lens are coated with an anti-reflective coating.

[0032] It is further preferred that the liquid crystal display has a matrix of liquid crystal cells which rotate the polarization direction of the transmitted light in a voltage-dependent manner in each liquid crystal cell, and that a linear polarization filter is arranged upstream (polarizer) and downstream (analyzer) of the liquid crystal cells, wherein the polarization filters are rotated 90° relative to each other such that light whose polarization direction has not been rotated in the liquid crystal cells is absorbed in the subsequent polarization filter (analyzer).

[0033] It is also preferred that parallel linear polarization filters are arranged on both sides of the liquid crystal cells, so that only light whose polarization direction has not been rotated in the liquid crystal cells is transmitted. This results in a higher light yield, albeit with lower contrast.

[0034] Another preferred embodiment is characterized in that at least one of the polarization filters is a brightness enhancement film, in particular the polarization filter arranged upstream of the liquid crystal cells.

[0035] It is further preferred that at least one polarization filter is designed as a reflective wire mesh polarizer, in particular the polarization filter arranged upstream of the liquid crystal cells.

[0036] It is also preferred that the polarizing filters are combinations of reflecting and absorbing polarizing filters arranged one behind the other in the direction of the luminous flux.

[0037] It is further preferred that the projection lens is a converging lens, in particular an aspherical converging lens.

[0038] It is also preferred that the projection lens is a refractive-diffractive hybrid lens.

[0039] It is further preferred that the projection lens is a Steinheil periscope lens, i.e. a wide-angle lens consisting of two meniscus lenses arranged with their concave sides to each other, wherein the meniscus lenses are in particular aspheric meniscus lenses.

[0040] Another preferred embodiment is characterized by the fact that all or individual lenses of the objective are made of plastic, in particular PMMA, PC, PEI, COC or COP.

[0041] It is also preferred that the lenses of the objective are coated.

[0042] It is further preferred that a deflecting mirror folding the beam path is arranged between the liquid crystal display and the projection lens, bending the beam path at right angles.

[0043] It is also preferred that the deflecting mirror is integrated into a projection lens as a reflective surface.

[0044] Further advantages will become apparent from the following description, the drawings, and the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0045] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description.

[0046] These show, each in schematic form: Fig. 1 an embodiment of a motor vehicle comfort projection device according to the invention; Fig. 2 a perspective view of a light guide rod with a light source; Fig. 3 details from the Fig. 2 in the form of alternative arrangements of light-emitting diodes; Fig. 4 A top view of a square arrangement of light of different colors, emitting light-emitting diodes; Fig. 5 a top view of an arrangement of two yellow light-emitting LEDs and two white light-emitting LEDs; Fig. 6 a top view of an arrangement of six light-emitting diodes; Fig. 7 a combination of seven light-emitting diodes; Fig. 8 a top view of the light emission surface of a light guide rod with a rectangular, here in particular square, cross-section; Fig. 9 a section through the light guide rod from the Fig. 8, which lies in a first plane of symmetry of the light guide rod; Fig. 10 a section through the light guide rod from the Fig. 8, which lies in a second plane of symmetry of the light guide rod; Fig. 11 a perspective view of the light guide rod from the Fig. 8 to Fig. 10; Fig. 12 an embodiment of a motor vehicle comfort projection device with an additional deflecting mirror. Fig. 13 an embodiment of a motor vehicle comfort projection device with a differently arranged deflecting mirror.

[0047] In detail, the Fig. 1 a motor vehicle comfort projection device 10 , which is a light source 12 , a conical optical fiber 14 , one as a field lens 16 serving converging lens and a liquid crystal display 18 as an imaging element and for displaying the liquid crystal display 18 set up projection lens 20 exhibits.

[0048] The light source 12 It is designed to emit light containing components of at least two different colors of light. The light source 12For example, it has several light-emitting diodes that differ in their light color.

[0049] The light source 12 together with the conical light guide, it forms 14 a mixing device with which the different colored light components are mixed completely evenly, resulting in different lighting colors for illuminating the liquid crystal display, depending on the LEDs used and their respective control. 18 have it generated.

[0050] The liquid crystal display 18 is thus between the light-emitting surface of the conical light guide 14 and the projection lens 20 arranged that the projection lens 20 an image of the liquid crystal display 18 into the lighting zone of the vehicle comfort projection device 10projected. The illumination zone can be the interior of a vehicle, but it can also be an area in the vicinity of the vehicle, for example, an entry area outside a vehicle door. The illumination zone can then form a carpet of light. The field lens 16 is directly in front of or behind the liquid crystal display 18 arranged.

[0051] How Fig. Figure 1 shows that the field lens is positioned between the light guide rod and the projection lens, and directly upstream of the imaging liquid crystal display (LCD), i.e., between the light guide rod and the LCD. Alternatively, the field lens can also be positioned downstream of the LCD, i.e., between the LCD and the projection lens.

[0052] The field lens is preferably a Fresnel lens. The convex Fresnel zones point in the direction of the incident light. The Fresnel zone surfaces are conical, spherical, or aspherical surfaces that share a common axis of rotation. The Fresnel lens is preferably made of glass, particularly organic glass. In an alternative embodiment, the Fresnel lens is made of PMMA, PC, PEI, COC, or COP. Its focal length is preferably equal to or greater than the focal length of the projection lens. The optical surfaces of the field lens are preferably coated with an anti-reflective coating.

[0053] The function of the field lens 16 consists of the light-emitting surface of the conical light guide. 14 Divergent (opening angle greater than 0°) light exiting the entrance pupil of the luminous flux downstream of the liquid crystal display 18 arranged projection lens 20 to focus. The field lens16 It thus acts as a condenser.

[0054] This characterizes the automotive comfort projection device. 10 not only through perfect light mixing and a completely homogeneously illuminated image field, but also through the combination of conical light guide 14 and field lens 16 Furthermore, it enables outstanding optical efficiency. Over 90% of the emitted light can be used for projection.

[0055] By directly focusing on the pupil of the projection lens 20 can be used for the projection lens 20 Comparatively inexpensive, low-light optics are used, which also offer good depth of field due to the small aperture ratio.

[0056] The automotive comfort projection device 10 further features a first polarization filter 19 (polarizer) and a second polarizing filter21 (Analyzer) on. The first polarization filter 19 is luminous flux upstream of the liquid crystal display 18 arranged. The second polarizing filter 21 is luminous flux downstream of the liquid crystal display 18 arranged.

[0057] The two polarizing filters 19 , 21 In a first alternative, the polarization directions (transmission directions) are arranged such that they intersect. The polarization directions preferably form a right angle. In a second alternative, the two polarization filters are 19 , 21 arranged so that their polarization directions are parallel to each other.

[0058] In one alternative, at least one of the two polarizers 19 , 21 a wire-grid polarizer. In another alternative, the polarizer 19a brightness enhancement film. The two polarizers 19 , 21 are preferably used with the liquid crystal display 18 glued together, so that the liquid crystal display 18 between the two polarizers 19 , 21 is arranged. In place of a polarizing filter. 19 , 21 A combination of a reflective and an absorbing polarizing filter can also be used. Each of the two polarizing filters 19 , 21 It only allows light of a specific polarization direction to pass through.

[0059] The explanations regarding the polarizers are intended to apply to all embodiments, even if the polarizers 19 , 21 For the sake of clarity, e.g., in the Fig. 12 and Fig. 13 are not shown.

[0060] The liquid crystal display 18As an image-forming element, it consists of many transparent cells filled with a liquid crystal fluid, arranged side by side in rows and columns, to which an electric field can be applied. To achieve good transmission, the liquid crystal display does not have a color filter.

[0061] Since each of the two polarizing filters 19 , 21 Only light of a specific polarization direction passes through; this occurs between the two polarization filters. 19 , 21 horizontal liquid crystal display 18 illuminated with polarized light.

[0062] Depending on the voltage applied to each individual cell, the polarization direction of the incident light in the liquid crystal display can be changed. 18The cells can be rotated individually. Depending on the polarization direction of the liquid crystal cells, a different amount of light passes through the polarization filter located downstream of the liquid crystal display. 21 (Analyzer), and cells of varying brightness result depending on the applied electrical voltage. In this way, different levels of brightness can be observed on the light-emitting surface of the liquid crystal display. 18 Create colored images.

[0063] In an arrangement of polarization filters 19 , 21 With intersecting polarization directions, light whose polarization direction was not rotated in the liquid crystal cells is filtered in the subsequent polarization filter. 21 (Analyzer) extinguished / absorbed, while light whose polarization direction was rotated in a liquid crystal cell passes through the second polarizing filter. 21 passes through it.

[0064] In an arrangement of polarization filters 19 , 21 With parallel polarization directions, only light whose polarization direction has not been rotated within the cells is transmitted. This results in lower contrast, but also higher light transmission.

[0065] The projection lens 20 The projection lens has a converging lens, in particular an aspheric converging lens. Alternatively, the projection lens is a refractive-diffractive hybrid lens. In a preferred alternative, the projection lens is a Steinheil periscope lens. Such a periscope lens is a wide-angle lens consisting of two meniscal lenses. 20.1 , 20.2 , which are arranged with their concave sides facing each other. The meniscal lenses 20.1 , 20.2 Aspheric meniscal lenses are preferred. 20.1 , 20.2 In a preferred embodiment, all or individual lenses consist of 20.1 ,20.2 of the projection lens 20 made of plastic, for example PMMA, PC, PEI, COC or COP. It is also preferred that the lenses of the projection lens are made of plastic. 20 are compensated.

[0066] The function of the projection lens 20 consists of displaying the image on the liquid crystal display. 18 into the lighting area of ​​the vehicle comfort projection device 10 , for example, to depict it in a vehicle interior.

[0067] Fig. Figure 2 shows a perspective view of a conical light guide. 14 a light source 12 , which consists of several light-emitting diodes. The light-emitting diodes of the light source 12 are located directly at a light entry surface of the conical light guide 14 The LEDs are arranged, but do not touch it. In particular, they are arranged so that the light emitted from them passes over the light-entry surface of the conical light guide.14 in the conical light guide 14 The LEDs are mounted on a circuit board. 22 mechanically held and electrically contacted. The circuit board 22 is attached to a heat sink 24 attached, which is designed to absorb heat released during the operation of the light-emitting diodes.

[0068] Fig. 3 shows details Z1 , Z2 from the Fig. 2 in the form of alternative arrangements of light-emitting diodes 12.i The light source 12 consists of several light-emitting diodes 12.1 These LEDs are densely packed and arranged side by side, and are designed to emit colored light, with the color of the light varying from one LED to the next. The LEDs can be controlled independently of each other, or separately according to color.

[0069] Fig. Figure 3 shows in particular various configurations of an arrangement of different colored light-emitting diodes. 12.i , e.g. as a 2x2 array, as detailed below. Z1 , with i = 1 to 4, or as a 2-3-2 arrangement, as detailed in Z2 , with i = i to 7.

[0070] Fig. Figure 4 shows an arrangement of three light-emitting diodes. 12.1 until 12.3 , with which light of a first color, such as white light, can be emitted, and a light-emitting diode 12.4 , with which light of a second color, for example yellow light, can be emitted. The light-emitting diodes 12.1 until 12.4 They are arranged in such a way that the sum of the LEDs forms a square.

[0071] Fig. Figure 5 shows a top view of an arrangement of two yellow light-emitting diodes. 12.1 , 12.2 and two white light-emitting diodes 12.3 , 12.4, which together form a square and in which the light-emitting diodes emitting light of the same color are each arranged along a diagonal of the square.

[0072] Fig. Figure 6 shows a top view of an arrangement of six light-emitting diodes. 12.1 until 12.6 , which are arranged in a 3x2 matrix and of which each one emits a red light (light-emitting diode) 12.1 ), a green light (light-emitting diode) 12.2 ), a blue light (light-emitting diode) 12.3 ), a violet light (light-emitting diode) 12.4 ), a white light (light-emitting diode) 12.5 ) and a yellow light (light-emitting diode) 12.6 can emit.

[0073] Fig. 7 shows a combination of seven light-emitting diodes. 12.1 until 12.7 , six of which are surrounded by a central seventh light-emitting diode 12.7 are arranged around them. Two of the light-emitting diodes (LEDs) 12.1 , 12.2) are designed to emit white light. The other light-emitting diodes 12.3 until 12.6 are designed to emit light of a single color, with the color varying from one LED to the next. A light-emitting diode 12.3 It is designed to emit blue light. Another light-emitting diode 12.4 is designed to emit yellow light. Another light-emitting diode 12.5 It is designed to emit cyan-colored light. Another light-emitting diode 12.6 It is ultimately designed to emit cyan-colored light.

[0074] Blue light-emitting LED chips are preferably used to generate the various colors, and their light is converted into the respective colors by corresponding phosphor layers. By using LEDs in the primary colors red, green, and blue (and optionally other complementary colors), not only can the color coordinates of the mixed light be varied within wide limits, but a lighting system with a large spectral bandwidth and very good color rendering values ​​is also obtained, which is particularly important for sophisticated interior lighting in motor vehicles.

[0075] Furthermore, the automotive comfort projection device according to the invention enables the generation of rapid sequences of individual images in the primary colors, which can then be perceived by the viewer as colored moving images. Thus, color videos can be projected.

[0076] Fig. Figure 8 shows a top view of the light-emitting surface. 14.1 a conical optical fiber 14 The length L has a rectangular cross-section (side lengths B, H). The light-entry surface has side lengths b < B and h < H.

[0077] Fig. Figure 9 shows a section through the conical light guide 14 from the Fig. 8, perpendicular to a first plane of symmetry 14.2 of the light guide rod. Fig. Figure 10 shows a section through the conical light guide from the Fig. 8, perpendicular to a second plane of symmetry 14.3 of the conical light guide 14 lies.

[0078] Fig. Figure 11 shows a perspective view of the light guide rod from the Fig. 8 to Fig. 10.

[0079] The ratios of sides B and H of the light-emitting surface 14.1 to sides b and h of the light entry surface 14.4are preferably implemented as integers and are preferably in the range of 2 to 8 inclusive. The length L of the conical optical fiber. 14 This should include 2 to 8 times the diagonal D of the light-emitting surface. 14.1 be.

[0080] Taken together, the Fig. 8 to Fig. 11 a rod-shaped conical light guide 14 with a light entry surface 14.4 and a light-emitting surface 14.1 , where the light entry area 14.4 from the light-emitting surface 14.1 is separated by a lateral surface which consists of four side surfaces 14.5 It is composed of... The light entry surface 14.4 and the light-emitting surface 14.1 are parallel to each other. The conical light guide 14 is a truncated pyramid, whose orientation is perpendicular to the main direction of light propagation in the conical optical fiber. 14Horizontal cross-sections are all rectangular or square. The conical light guide 14 preferably consists of glass, in particular of an inorganic crown glass.

[0081] The corresponding side lengths of the light-entry surface and the light-emission surface preferably form integer multiples, in particular 2 to 8 times, such that one side length of the light-emission surface is, for example, 4 times as long as a side length of the light-entry surface parallel to that side length. The conical optical fiber preferably has two planes of symmetry. 14.2 , 14.3 on which the optical axis is located and which are each perpendicular to two side faces and the light-intake and light-outtake surfaces. The light-intake surface 14.4 and the light-emitting surface 14.1 The conical light guide is preferably coated with an anti-reflective coating.

[0082] The conical light guide 14 It serves as a light mixer and concentrator. The light from the light source emitting different colors 12 is in the conical light guide 14 , whose cross-section lying perpendicular to the main direction of light propagation increases with increasing distance from the light-entry surface 14.4 The light spectrum increases and is mixed by internal total internal reflections. At the same time, the opening angle of the light is reduced as a result of reflections at the side surfaces of the conical optical fiber.

[0083] Fig. Figure 12 shows an embodiment of a motor vehicle comfort projection device 10 , which differ from the motor vehicle comfort projection device 10 the Fig. 1 by an additional deflecting mirror 26 This differs. The deflecting mirror is located in the beam path between the liquid crystal display. 18 and the projection lens 20, or between the second polarizing filter 21 and the projection lens 20 and bends the beam path by a bending angle. The bending angle is preferably 70° to 110°, particularly 90°.

[0084] Fig. Figure 13 shows an embodiment of a motor vehicle comfort projection device 10 , which differ from the motor vehicle comfort projection device of the Fig. 12 by a different arrangement of the deflecting mirror 26 differs. In contrast to the subject of the Fig. The deflecting mirror is located at 12. 26 in the beam path downstream of the projection lens 20 and bends the beam path by an angle. Here too, the angle of bending is preferably 70° to 110°, particularly 90°.

[0085] Another embodiment is characterized by the fact that the deflecting mirror is integrated as a reflective surface into a lens of the projection lens. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10215893 C1

[0001]

Claims

[1] Motor vehicle comfort projection device (10), comprising a light source (12) and a projection lens, characterized by , that the motor vehicle comfort projection device (10) comprises a conical light guide (14), a converging lens serving as a field lens (16) and a liquid crystal matrix display (18) as an imaging element and a projection lens (20) designed to image the liquid crystal display (18). [2] Motor vehicle comfort projection device (10) according to claim 1, characterized by , that the light source (12) has light-emitting diodes (12.i) with at least two different light colors. [3] Motor vehicle comfort projection device (10) according to claim 2, characterized by , that the light-emitting diodes (12.i) can be controlled independently of each other, or separately according to color. [4] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by, that the cross-section of the conical optical fiber (14) lying perpendicular to the main propagation direction in the conical optical fiber (14) is rectangular or square. [5] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the length of the conical optical fiber (14) in the main direction of propagation of the light is 2 to 8 times the diagonal (D) of the light exit surface (14.1) of the conical optical fiber (14). [6] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the corresponding side lengths of the light entry surface (14.4) and the light exit surface (14.1) of the conical light guide (14) differ by an integer factor, where the factor can have the values ​​2 to 8 and the light exit side is longer than the corresponding light entry side. [7] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the conical optical fiber (14) has two planes of symmetry (14.2, 14.3) which contain the optical axis and which are each perpendicular to two side faces and to the light entry surface (14.4) and to the light exit surface (14.1) of the conical optical fiber (14). [8] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the field lens (16) is arranged upstream of the liquid crystal display (18) between the conical light guide (14) and the liquid crystal display (18) or between the conical light guide (14) and a first polarizer (19). [9] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by, that the field lens (16) is arranged downstream of the liquid crystal display between the liquid crystal display and the projection lens (20) or between a second polarizer and the projection lens (20). [10] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the field lens (16) is a Fresnel lens (16.1) and that Fresnel zones of the Fresnel lens (16.1) point in the direction of the incident light. [11] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the focal length of the field lens (16) is greater than or equal to the focal length of the projection lens (20). [12] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by, that the liquid crystal display (18) has a matrix of liquid crystal cells which rotate the polarization direction of the transmitted light in a voltage-dependent manner in each liquid crystal cell, and that a polarization filter (19) is arranged upstream of the liquid crystal display (polarizer) and a polarization filter (21) is arranged downstream of the liquid crystal display (18), wherein the polarization filters (19, 21) are rotated 90° relative to each other such that light whose polarization direction has not been rotated in the liquid crystal display (18) is absorbed in the subsequent polarization filter (21) (analyzer). [13] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that parallel aligned linear polarization filters (19, 21) are arranged on both sides of the liquid crystal display (18) so that only light whose polarization direction has not been rotated in the liquid crystal display (18) is transmitted. [14] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the polarization filter (19) arranged upstream of the liquid crystal display (18) is a brightness enhancement film. [15] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the polarizing filters (19, 21) are combinations of reflecting and absorbing polarizing filters arranged one behind the other in the direction of the luminous flux. [16] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the projection lens (20) has a converging lens, in particular an aspheric converging lens. [17] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the projection lens (20) is a refractive-diffractive hybrid lens. [18] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that the projection objective (20) is a Steinheil periscope lens, i.e. a wide-angle objective consisting of two meniscus lenses (20.1, 20.2) arranged with their concave sides to each other, wherein the meniscus lenses (20.1, 20.2) are in particular aspheric meniscus lenses (20.1, 20.2). [19] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that a deflecting mirror (26) folding the beam path is arranged between the liquid crystal display (18) and the projection lens (20), which bends the beam path. [20] Motor vehicle comfort projection device (10) according to one of the preceding claims, characterized by , that a deflecting mirror that folds the beam path is integrated as a reflective surface into a lens of the projection objective.

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