Thermoplastic film for a laminated-glass pane having a non-linear continuous wedge insert in the vertical and horizontal direction in some sections

Abstract

A thermoplastic film for a laminated-glass pane, having a non-linear continuous wedge insert in both a vertical and horizontal direction in some sections, is described. In the vertical direction, the laminated-glass pane is, from the perspective of an observer, further at a lower end than at an upper end. In a laminated-glass pane equipped with the thermoplastic film, the thermoplastic film is located between two glass layers. The thermoplastic film has at least a first section having a wedge angle profile that is continuous and non-linear in the vertical and horizontal direction, such that ghost images from a head-up display are minimized in the region of the first section. The thermoplastic film also minimizes double images in transmission in the first section and in further sections.

Claims

1. A method for producing a thermoplastic film for a laminated glass pane with a nonlinear continuous wedge insert in vertical and horizontal direction, the laminated glass pane being farther from an observer in the vertical direction at a lower end from a perspective of the observer than at an upper end, the thermoplastic film being adapted to be situated between two glass layers of the laminated pane, the method comprising: calculating a vertical wedge angle required for compensation of ghost images in a first section as a function of a local angle of incidence and a local radius of curvature of the laminated glass pane; determining a resultant progression of a vertical wedge angle; calculating a horizontal wedge angle required for compensation of ghost images in the first section as a function of the local angle of incidence and the local radius of curvature of the laminated glass pane; determining a resultant progression of the horizontal wedge angle; calculating a wedge angle required for compensation of the double image as a function of the local angle of incidence and the local radius of curvature of the laminated glass pane; and determining a resultant progression of the wedge angle; wherein the thermoplastic film includes the first section having a continuous nonlinear wedge-angle profile in vertical and horizontal directions such that ghost images from a head-up display are minimized in a region of the first section, and the thermoplastic film minimizes double images in transmission in the first section.

2. A thermoplastic film for a laminated glass pane with a nonlinear continuous wedge insert in vertical and horizontal direction, the laminated glass pane being farther from an observer in the vertical direction at a lower end from a perspective of the observer than at an upper end, the thermoplastic film being adapted to be situated between two glass layers of the laminated pane, the thermoplastic film comprising: at least a first section having a continuous nonlinear wedge-angle profile in the vertical and horizontal direction such that ghost images from a head-up display are minimized in a region of the first section; wherein the wedge angle in the vertical direction in the center of the thermoplastic film inside the first section varies between 0.8 mrad and 0.1 mrad, the wedge angle in the vertical direction in the center of the thermoplastic film varies between 0.6 mrad and 0.1 mrad, the wedge angle from a lower end to an upper end is a function of the distance from the lower end or from the upper end, the function being at least a second degree function, and the thermoplastic film minimizes double images in transmission in the at least first section.

3. The thermoplastic film according to claim 2, wherein the thermoplastic film contains at least one material selected from the group consisting of polybutylene terephthalate (PBT), polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyvinyl chloride (PVC), polyvinyl fluorides (PVF), polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyacrylate (PA), polymethyl methacrylate (PMMA), polyurethane (PUR), and mixtures and copolymers thereof.

4. The thermoplastic film according to claim 2, wherein the wedge angle at a lower edge is smaller than the wedge angle at an upper edge of the laminated glass pane.

5. The thermoplastic film according to claim 2, wherein the thermoplastic film has, at a lower edge, a thickness of less than 1 mm.

6. The thermoplastic film according to claim 2, wherein in a region outside the first section the thermoplastic film has, in the vertical direction, a wedge-angle profile that has, for prevention of double images in transmission, a wedge angle that is constant or variable at least in some sections.

7. The thermoplastic film according to claim 2, wherein the wedge angle in the vertical direction in the center of the first section of the thermoplastic film is greater in some sections than the wedge angle in the vertical direction at a different horizontal position inside the first section.

8. A laminated glass pane, comprising: a first glass layer and a second glass layer; and the thermoplastic film according to claim 2, located between the first glass layer and the second glass layer.

9. The laminated glass pane according to claim 8, wherein the laminated glass pane has a thickness of 1 mm to 8 mm at the lower end.

10. The laminated glass pane according to claim 8, wherein the first glass layer and/or the second glass layer have a thickness selected from a range of about 1 mm to 3 mm at the lower end.

11. A head-up display arrangement, comprising: a projector for illuminating a head-up display region of a laminated glass pane; and the laminated glass pane comprising the thermoplastic film according to claim 8, wherein, during operation, the projector substantially illuminates a second section.

12. A method for producing the laminated glass pane, comprising: obtaining a first glass layer and a second glass layer; placing a thermoplastic film on the first glass layer; placing the second glass layer on the thermoplastic film; bonding the first glass layer to the thermoplastic film; and bonding the second glass layer to the thermoplastic film, wherein the thermoplastic film includes: at least a first section having a continuous nonlinear wedge-angle profile in the vertical and horizontal direction such that ghost images from a head-up display are minimized in a region of the first section, wherein the wedge angle in the vertical direction in the center of the thermoplastic film inside the first section varies between 0.8 mrad and 0.1 mrad, the wedge angle in the vertical direction in the center of the thermoplastic film varies between 0.6 mrad and 0.1 mrad, the wedge angle from a lower end to an upper end is a function of the distance from the lower end or from the upper end, the function being at least a second degree function, and the thermoplastic film minimizes double images in transmission in the at least first section.

13. The method according to claim 12, comprising: calculating the wedge angle as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane; and determining a resultant progression of the wedge angle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the present invention are described by way of example with reference to the appended drawings, which depict:

(2) FIG. 1 the basic context of the development of double images in transmission,

(3) FIG. 2 the basic context of the development of ghost images in reflection,

(4) FIG. 3 an exemplary structure of a laminated glass pane with a wedge-shaped interlayer,

(5) FIG. 4 an exemplary wedge-angle profile for compensation of double images in transmission,

(6) FIG. 5 an exemplary arrangement that demonstrates the relationship of different eye positions relative to a head-up display.

(7) FIG. 6 wedge-angle values determined as examples for different vertices of an HUD region that correspond to different eye positions,

(8) FIG. 7 an exemplary wedge-angle profile for compensation of ghost images in reflection,

(9) FIG. 8 an exemplary distribution of double image angles on a laminated glass pane,

(10) FIG. 9 an exemplary distribution of the distance between the ghost image and the desired HUD image on a HUD region of a laminated glass pane, and

(11) FIG. 10 a combined view of an exemplary wedge-angle profile in a cross-section through the HUD field for compensation of double images in transmission in individual sections and for compensation of ghost images in reflection in another section.

DETAILED DESCRIPTION OF THE INVENTION

(12) FIG. 1 depicts the basic context of the development of double images in transmission using a beam image. A curved pane 1 is assumed. The curved pane has, at the point of entry of the beam into the curved glass pane 1, a radius of curvature (R+D). Light is now emitted from the light source 3. This light strikes the pane and is refracted in accordance with known refraction laws at the transition from air to glass on the first boundary and from glass to air on the second boundary and reaches the eye 2 of an observer. This beam is depicted as the solid line P. From the perspective of the observer, the light source 3 appears to be situated at the location 3. This is depicted as beam P. However, in addition to this beam P referenced as the primary beam, the beam is only partially refracted on the second gas/air boundary in the manner described above; a smaller fraction is reflected on the second boundary and is once again reflected on the first boundary before the beam now passes through the second boundary and reaches the eye 2 of the observer. This beam, the so-called secondary beam is depicted as a dashed line S. From the perspective of the observer, the light source 3 also appears to be situated at the location 3. The angle enclosed by the primary beam P and the secondary beam S is the so-called double image angle.

(13) In order to address this double image, provision can now be made that a wedge angle be provided between the two boundary layers assumed to be substantially parallel in FIG. 1. According to J. P. Aclocque Doppelbilder als strender optischer Fehler der Windschutzscheibe [Double Images As Interfering Optical Errors in Windshields] in Z. Glastechn. Ber. 193 (1970) pp. 193-198, the double image angle can be calculated as a function of the radius of curvature of the glass pane and the angle of incidence of the light beam according to the following equation:

(14) $=\frac{2d}{R}.Math.\frac{\sin }{\sqrt{n^2-{\sin }^2}},$
where
is the double image angle, n is the index of refraction of the glass, d is the thickness of the glass pane, R is the radius of curvature of the glass pane at the location of the incident light beam, and is the angle of incidence of the light beam relative to the perpendicular on the tangent to the pane.

(15) In the case of flat glass panes, the double image angle is, according to the following formula,

(16) $=2.Math..Math.\frac{\sqrt{n^2-{\sin }^2}}{\cos }$
a function of the wedge angle formed by the glass surfaces.

(17) Thus, by setting the aforementioned formulas equal, the wedge angle necessary for the elimination of the double image can be calculated:

(18) $=\frac{d}{R}.Math.\frac{\cos .Math.\sin }{n^2-{\sin }^2}.$

(19) Generally, this wedge angle is realized in that in laminated glass panes 1 a wedge-shaped intermediate layer F is placed between a first glass layer GS.sub.1 and a second glass layer GS.sub.2, see FIG. 3. It can generally be assumed for the sake of simplicity that the index of refraction n is constant, since the difference in the index of refraction of the intermediate layer F and the glass panes GS.sub.1, GS.sub.2 is rather small such that there is hardly any effect due to the small difference.

(20) This idea can be also applied with curved windshields. Generally, for the sake of simplicity the angle of incidence and the radius of curvature are assumed for a reference eye point, and the wedge angle determined therewith is used for the entire windshield.

(21) In the case of large laminated glass panes 1, so-called panorama panes, and/or more highly curved laminated glass panes 1, this approach is, however, no longer adequate such that here, generally, a wedge-angle progression variable in the vertical direction must be determined.

(22) Then, it is possible, for example, by pointwise calculation along an imaginary vertical center line of a laminated glass pane and possible interpolation, to determine a compensation wedge-angle profile .

(23) For the calculation of the double image angle and the corresponding local compensation wedge angle , the arrangement as recommended in the Test Specification ECE R43 Annex 3 for determining the double image angle can be selected. With this arrangement, the double image angles are determined when the head of the driver moves from a lower position in the vertical direction to an upper end position. In other words, the driver's line of sight always remains horizontal. However, alternatively or additionally, an arrangement can be selected in which the double image angle is calculated from a mean unchanging position of the driver (eye point), where the angle of sight of the driver through the windshield changes. The result of different determination variants can be transformed, even with weighting, into an overall result.

(24) An exemplary wedge-angle profile, i.e., a progression of the wedge angle as a function of the distance from the hood edge, i.e., to the lower end of a laminated glass pane 1, is shown in FIG. 4. It is clearly discernible that a wedge angle for an imaginary virtual center line optimized according to the above formulas begins, in the exemplary windshield, at the lower end initially with values of less than 0.15 mrad and with increasing distance from the hood edge, i.e., toward the upper end of the laminated glass pane 1, increases to values of more than 0.4 mrad.

(25) In an exemplary method, the wedge angle required for compensation of the double image is calculated mathematically as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane 1, and the resultant progression of the double image angle is determined. By way of example, a possible result of double image angles is shown in FIG. 8 for a laminated glass pane 1 of a motor vehicle. Here, an exemplary laminated glass pane 1 is mapped onto an xy coordinate system, wherein the horizontal axis indicates a distance relative to the center of the laminated glass pane 1 and the vertical axis indicates a distance relative to a lower plane (not shown). It should be noted that the representation of the pane does not necessarily correspond to its actual installation, but is depicted in the figure such that the greatest possible projection surface is present. The resultant double image angle is reported in arc minutes.

(26) With regard to head-up displays, a problem develops which is similar to the phenomenon of double images and is referred to as a ghost image.

(27) FIG. 2 presents the basic context of the development of ghost images in reflection with reference to a beam image. Here, a curved glass pane 1 is assumed. The curved glass pane 1 has a radius of curvature R at the location of the entry of a beam into the curved glass pane 1. Light is now emitted from the light source 3, which is representative of a head-up display HUD. This light impinges on the glass pane 1 along the beam R.sub.i from the inside at an angle and is reflected there at the same angle . The reflected beam R.sub.r reaches the eye 2 of an observer. This beam path is depicted as a solid line. From the perspective of the observer, the light source 3 appears to be situated virtually at the location 3, i.e., in front of the glass pane 1. This is depicted as beam R.sub.v. In addition to this first beam, another beam reaches the eye 2 of the observer. This beam R.sub.i likewise originates from the light source 3. However, this beam R.sub.i penetrates, in accordance to the known laws of refraction, into the glass pane 1 on the inner air/glass boundary surface and is reflected on the outer glass/air boundary surface before the beam passes through the inner boundary surface and reaches the eye 2 of the observer as beam R.sub.r. The term inner boundary surface thus refers to the boundary surface that is situated closer to the observer, whereas the term outer boundary surface refers to the boundary surface that is farther away from the observer. This beam path is depicted as a dashed line. From the perspective of the observer, the light source 3 appears to be situated virtually at the location 3, i.e., likewise in front of the glass pane 1. This is depicted as beam R.sub.v.

(28) To address this problem, the wedge angle can now be altered such that the beam R.sub.r reflected on the outer boundary surface and the beam R.sub.r reflected on the inner boundary surface overlap relative to the eye 2 of the observer, i.e., the beam reflected on the outer boundary surface exits at the point of reflection of the beam impinging on the inner boundary surface.

(29) However, if this is done only for a single eye position, as is customary according to the prior art, the wedge angle determined therefrom can yield non-optimum results. This can be explained, among other things, by the fact that both the body sizes of drivers for whom the head-up displays are primarily intended and the seating position are very different such that there are a large number of possible eye positions. This is illustrated in FIG. 5. There, two possible eye positions 2 and 2a are depicted on the right side of FIG. 5. The position of the image 3 or 3a results as a function of the eye position 2 or 2a. Even the region of the pane in the head-up display region HUDB (active region) involved in the optical process for image generation is a function of the eye position 2, 2a. As a model, the projector image 3 and virtual image 3, 3a can be construed as full area rectangles. The connecting lines from the eye position 2, 2a to the corners of the rectangles are drawn in the figure. The intersections of these connecting lines with the pane yield the corners of a trapezoid which, by way of a model, should describe the active region of the pane. These trapezoids are depicted, by way of example, inside the head-up display region HUDB on the glass pane 1 in the figure. Thus, the virtual display is situated in different places depending on the eye position and, accordingly, there is, for each of these eye positions, possibly a different value for an optimized wedge angle. In addition, it should be mentioned here that a wedge angle optimized exclusively for ghost images usually results in overcompensation of double images such that the double images thus caused are again problematic relative to the perception of the observer and/or compliance with regulatory test specifications and/or compliance with customer specifications relative to double images.

(30) FIG. 6 reports the resultant positions of an HUD in the form of the above-described trapezoid (as active regions) within a head-up display region HUDB for different positions of the eye 2 relative to the laminated glass pane 1. For better differentiation, the trapezoids are presented with different types of lines. For clarity, the associated wedge angles determined for a number of trapezoids are indicated relative to the corners of the trapezoids and entered on the left side relative to the distance from the hood edge.

(31) By way of example, vertical section lines Y400, Y400 bzw. Y600, Y600, and Y0 are drawn in in FIG. 8.

(32) FIG. 7 shows possible optimum progressions of the wedge-angle profile for these vertical section lines Y400, Y400 bzw. Y600, Y600, and Y0 relative to the distance from the head-up display region. It is readily discernible for each of the profiles in FIG. 7 that it is in each case continuous and nonlinear. It can also be readily deduced that the horizontal wedge-angle profile for a specific distance from the lower edge varies smoothly from Y400 to the value at Y0. The vertical wedge-angle profile of the sections Y0, Y600, and Y600 is optimized such that the double image in transmission is reduced. This is advantageous for sections outside the HUD region HUDB, since there no contribution has to be made for compensation of ghost images in reflexion. The sections depicted are provided as examples and are, in particular, dependent on the vehicle model. It can also be readily deduced that the horizontal wedge-angle profile for a specific distance from the lower edge varies smoothly from Y400 to the value at Y600. Also from FIG. 6, corresponding wedge-angle profiles could be readily determined for individual section lines.

(33) In an exemplary method, the wedge angle required for compensation of the double image is calculated as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane 1, and the resultant progression of the wedge angle is determined. By way of example, a possible result of perceived location-shifted ghost images is depicted in FIG. 9 for a head-up display region HUDB of a laminated glass pane 1 of a motor vehicle. This head-up display region HUDB corresponds to the left detail HUDB (and, in a mirror image, also to the right detail HUDB) in FIG. 8. The advantage of such a mirror-image symmetrical design resides in the fact that the same pane is equally suitable for vehicles in countries with driving on the right and for vehicles in countries with driving on the left. However, in principle, the pane can also be designed asymmetrically, with the HUDB arranged preferably only in the half of the pane that is in front of the driver position in the installed position. In this respect, the horizontal axis again refers to a distance relative to the center of the laminated glass pane 1. Here, however, the vertical axis relates to the deepest point of the head-up display region HUDB. The figure now shows the distance between a primary image and a secondary image in mm.

(34) By means of such a thermoplastic film F, it is readily possible to minimize both double images in transmission and also ghost images and reflection depending on requirements at any desired location. Thus, even large head-up display regions HUDB can be realized.

(35) Without loss of generality, provision can also be made that the thermoplastic film F not only makes available, within the first section A2, optimization with regard to ghost images and possibly also with regard to double images, but provision can, for example, also be made that, in the region outside the first section A2, the thermoplastic film F has a wedge-angle profile in the vertical direction that has a constant wedge angle or a wedge angle variable at least in some sections to prevent double images in transmission. An exemplary wedge-angle profile Y400 or Y400 is depicted in FIG. 10. There, in the lower half, an optimized wedge-angle progression for optimization of double images in transmission determined according to the above formula relationship for an exemplary laminated glass pane 1 is depicted using diamonds for specific distances from the hood edge. Also, in the section A.sub.2, the progression optimized for ghost images is shown as a solid line.

(36) The two curves can now be brought closer together, with a large open space being present here for the optimization. Thus it is possible to use, for example, as indicated in FIG. 10 in the outer regions A.sub.1 and A.sub.3 with regard to the first section A.sub.2 as a transition region, with, for example, a slight overcompensation of double images occurring in the region of the section A.sub.1, and also with a slight undercompensation occurring in the region of the section A.sub.3. A possible wedge-angle profile can be provided in the dash-dot lines in the sections A.sub.1 and A.sub.3, which enable a seamless transition into the first section A.sub.2. Here, different factors can be taken into account; thus, it can, for example, be desirable to minimize double images more than ghost images in the first section A.sub.2, then it would be possible, for example, to shift the curve depicted as a solid line in section A.sub.2 closer to the diamond curve or else to align the two curves with each other using suitable approximation solutions. In this process, other parameters, such as a maximum wedge angle or a maximum wedge-angle change, can also be taken into account. Such parameters can, for example, result from the fact that a change in the thickness of the laminated glass pane 1 must not exceed a maximum value. The wedge-angle profile in the other sections can easily also be purely linear and, for example, have a fixed wedge angle in the vertical direction.

(37) Preferably, with regard to the first section A.sub.z as depicted in FIG. 7, the wedge-angle profile can be designed such that the wedge angle in the vertical direction in the center of the first section A.sub.2 of the thermoplastic film, i.e., for example, at Y400, is larger than the wedge angle in the vertical direction at a different horizontal position, i.e., for example, Y390 or Y410, inside the first section A.sub.2. Generally, this also applies to all other regions outside of section A.sub.2, i.e., outside the head-up display region HUDB of the laminated glass pane 1.

(38) In embodiments of the invention, provision can also be made that, as depicted in FIG. 7, the wedge angle Y400 in the vertical direction in the center of the thermoplastic film F inside the first section varies between 0.75 mrad and 0.15 mrad, whereas the wedge angle Y0 in the vertical direction in the center of the thermoplastic film F varies somewhere between 0.6 mrad and 0.1 mrad. In this case, the wedge angle from a lower end to an upper end can be understood as a function of the distance from the lower end or from the upper end, wherein the function is, for example, at least a second degree function.

(39) In the invention, the wedge-angle profile can be particularly easily determined due to the fact that vertical wedge angles required for compensation of ghost images in the first section A.sub.2 can be calculated as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane 1 for various eye positions. The resultant progression of the vertical wedge angle is determined, for example, for a specific number of vertical sections, e.g., at the edge and in the center. In addition, the horizontal wedge angle required for the compensation of ghost images in the first section is calculated as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane 1, if this has not already occurred, and the resultant progression of the horizontal wedge angle is determined. Furthermore, the wedge angle required for compensation of the double image is now calculated as a function of the local angle of incidence and a local radius of curvature of the laminated glass pane 1, and the resultant progression of the wedge angle is determined. For reasons of simplification, it can, in particular, in the latter step, be possible to determine these values only for a single vertical profile, for example, Y0, since, frequently, the values for other vertical profiles, e.g., profile Y400, differ only insignificantly from this. Thus, the calculational effort can be kept manageable.

(40) Such a thermoplastic film F can contain at least one material selected from the group comprising polybutylene terephthalate (PBT), polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyvinyl chloride (PVC), polyvinyl fluorides (PVF), polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyacrylate (PA), polymethyl methacrylate (PMMA), polyurethane (PUR), and/or mixtures and copolymers thereof. The selection of a suitable material for the thermoplastic film F can, for example, depend on the properties of the film with regard to the refractive index and also the strength achievable with regard to a certain film thickness. In principle, the invention is not restricted to a specific material for a thermoplastic film F.

(41) In order to minimize double images, in the laminated glass panes 1 generally installed at an angle in vehicle construction, a wedge-angle profile is preferred, wherein, in the vertical direction, the wedge angle at the lower edge is smaller than the wedge angle at the upper edge, i.e., the wedge angle in the vicinity of the vehicle hood is smaller than the wedge angle in the vicinity of the roof edge of a typical motor vehicle.

(42) For manufacture, it is particularly advantageous for the thermoplastic film F according to the invention to have, at the lower edge, a thickness of less than 1 mm, preferably less than 0.9 mm, and preferably a thickness of more than 0.3 mm, in particular more than 0.6 mm. As a result, the film can be used in a proven manner in the production of laminated glass panes 1, without the need for cost-driving special equipment.

(43) Thus, a structure of a laminated glass pane 1, as shown in FIG. 3, can be obtained even with the thermoplastic film F according to the invention between a first glass layer GS.sub.1 and a second glass layer GS.sub.2.

(44) Such laminated glass panes 1 have a thickness of 1 mm to 8 mm, preferably 3.5 to 5.3 mm, and can thus readily be further processed like conventional laminated glass panes.

(45) Here, the first glass layer GS.sub.1 and/or the second glass layer GS.sub.2 of the laminated glass pane 1 typically have a thickness selected from a range of roughly 1 mm to 3 mm, preferably of 1.4 mm to 2.6 mm auf. This guarantees the required properties of splinter protection and/or sound insulation.

(46) With the thermoplastic film F, a laminated glass pane 1 can thus be produced in a proven manner, in that a first glass layer GS.sub.1 and a second glass layer GS.sub.2 are obtained, wherein the thermoplastic film F is placed on the first glass layer GS.sub.1, and the second glass layer GS.sub.2 is placed on thermoplastic film with the use of an autoclave process. Thereafter, the thermoplastic film F is bonded to the first glass layer GS.sub.1 and the second glass layer GS.sub.2 in the autoclave under the action of heat and pressure.

(47) Of course, the thermoplastic film F according to the invention can be used not only in an autoclave process but can, for example, also be used with a vacuum thermal furnace process or similar autoclave-free processes.

(48) It is also, in principle, possible to initially bond only a first glass layer GS.sub.1 to the thermoplastic film F after placement and only after that to place the second glass layer GS.sub.2 and to bond it to the thermoplastic film F previously bonded to the glass layer GS.sub.1.

(49) Thermoplastic films F thus produced can be used in laminated glass panes 1 in motor vehicles, in particular as windshields for display of a head-up display, or in buildings or as data displays.

(50) Use in a head-up display arrangement can be seen, for example, in FIG. 5. There, a projector as a light source illuminates an exemplary head-up display region HUDB of a laminated glass pane 1, which is equipped with a thermoplastic film F according to the invention. Ghost images of the projector are minimized in the head-up display region HUDB, whereas the entire laminated glass pane 1 also reduces double images in transmission (not shown).

(51) As a result, the invention enables improvement with regard to minimization of ghost images of head-up displays for a large number of eye positions without generating substantially more ghost images outside the head-up display region HUDB. Furthermore, by means of the invention, it can also be accomplished that in the head-up display region HUDB as well as in the other regions, double images in transmission can be reduced. In addition, larger head-up display regions HUDB as well as more complex windshield curve designs can be realized with the invention presented.

(52) Although in the figures in general only a head-up display region HUDB is depicted, the invention is not restricted thereto. For example, even more head-up display regions HUDB, e.g., for right-hand and left-hand vehicles or even for different purposes, such as an infotainment system and driver assistance systems can be provided. Provision can also be made that, for example, in the case of head-up display regions HUDB that are used substantially in infotainment, only minimization of ghost images is provided, whereas with driver assistance systems both minimization of ghost images and minimization of double images is sought.

(53) As a result, the invention enables improvement with regard to minimization of ghost images of head-up displays for a large number of eye positions without generating substantially more ghost images outside the head-up display region HUDB. Furthermore, by means of the invention, it can also be accomplished that in the head-up display region HUDB as well as in the other regions, double images in transmission are reduced. In addition, larger head-up display regions HUDB as well as more complex windshield curve designs can be realized with the invention presented.