EP2195698A1

EP2195698A1 - Head-up display

Info

Publication number: EP2195698A1
Application number: EP08805003A
Authority: EP
Inventors: Hans-Georg Heckmann; Friedrich Neuner; Johannes Dumanski
Original assignee: Linos Photonics GmbH and Co KG
Current assignee: Qioptiq Photonics GmbH and Co KG
Priority date: 2007-10-02
Filing date: 2008-10-02
Publication date: 2010-06-16
Also published as: WO2009047202A2; EP2045647A1; DE102007047232A1; WO2009047202A3; EP2195695A2; WO2009047200A1

Abstract

The invention pertains to a head-up display, in particular for a motor vehicle with a projection unit (1) to generate a virtual picture. At least one constituent (3) of the projection unit (1) is arranged in a moveable manner in order to ensure a height offset of the virtual picture. According to the invention, a combiner (2) is arranged in the beam path after the projection unit (1) for viewing of the virtual picture, wherein the combiner (2) is likewise moveably mounted. Thus, the head-up display can be easily adapted to the size of the driver.

Description

Head-Up Display

The invention relates to a head-up display according to the preamble of claim 1.

Classic head-up displays combine information generated for the driver of a vehicle with the scene in front of the vehicle. In order to impede the driver's view as little as possible, the superimposed signal is displayed as a virtual image in front of the windshield, so that the driver can observe the surroundings and the displayed data as simultaneously as possible without having to accommodate the eye differently.

Such head-up displays have long been known in various embodiments, so that the demands on the image quality and the size of the eyebox and the image field, which leads to large and therefore technically problematic image angles, are constantly increasing. In addition, it is now expected that head-up displays are multi-colored. In particular, for head-up displays in the field of water and land vehicles, unlike in the aircraft sector, they must be able to be produced as inexpensively as possible.

All these functions should be guaranteed without sacrificing quality for drivers of different sizes, with different viewing angles. Already from DE 37 12 663 A1 is known to realize a head-up display height adjustable. In order to adapt the head-up display to the size of the driver, it is proposed to displace the components of the imaging optics.

In this way, however, the height of the imaginary image moves along the windshield, allowing it to extend very far into the field of vision of very tall drivers and thus severely obstruct the external view. In addition, it is anyway difficult to optimize and adjust the optics so that it meets the extremely high quality requirements with cost-effective space-saving design, with a displacement of the entire beam path, it is almost impossible.

The invention has for its object to realize a high-quality head-up display height adjustable.

The object is achieved according to the invention by a head-up display with the features of claim 1.

According to the invention, in a height-adjustable head-up display in which the beam path is displaceable, not the windshield for viewing the virtual image is used but worked with a separate combiner, which is movably mounted. The display of the image on a separate, moveably mounted combiner opens the possibility, via a pivoting movement of the combiner, the vertical offset of a component of the projection unit in a vertical offset of the beam at the viewer's location (ie a vertical offset of the eyebox) without height offset of the virtual image to reach the location of the windshield. In addition, a separate combiner offers the possibility of realizing a large eyebox with an equally large viewing angle while maintaining a good image quality, especially a multi-color image by the combiner is provided with a greater curvature or refractive power compared to a windshield and with respect Image quality can be optimally designed. This makes it possible to maintain the image quality even with a pivoting movement of the beam path.

Only then is it possible to realize a large field angle with small optical elements. Due to the greater refractive power of the combiner, problems with the solar focus can also be reduced at the same time, which, when using the windscreen as a combiner, can be reduced due to the large entrance opening. would come to light. In particular, it is also possible and advantageous for a separate combiner to apply special coatings which suppress double images and bring about the partial reflectivity.

Moreover, when using a combiner to view the virtual image, it is also not necessary for the combiner of the head-up display to be at the height of the windshield. It would also be possible to provide a combiner advantageously fully mirrored height of the dashboard. This has the advantage that the entire windscreen is available for visibility to the outside.

In a preferred embodiment, the movement is coupled by the beam displaceable component of the projection unit and the combiner. The coupling can be carried out electronically, preferably via two coordinated drive units. It is easier to couple mechanically, via a drive unit which is in communication with and drives the movable component, the combiner or the coupling and a mechanical coupling unit of the two components. In the latter case, a drive is sufficient and thus more cost-effective, the coupling takes place directly. Despite the displacement of the beam path of the virtual image, the ratios of incidence and reflection angles of the combiner and projection unit must be maintained, so that no optical errors, distortions or distortions occur. In particular, the combiner must not move out of the beam path. Therefore, the movement of the combiner is preferably tuned to the movement of the optical component.

Preferably, the combiner and the beam displacing optical component rotate about the same axis in the projection unit. As a result, the beam displacement takes place via a simple, controlled, coupled movement of the component of the projection unit and of the combiner. The common Axis is advantageously on the surface of the component of the projection unit. Preferably, the optical component of the projection unit performs a rotary movement, the combiner a pivoting movement.

In a preferred embodiment, the coupling between combiner and movably arranged component of the projection unit includes a translation. This allows the movement of the components at different angular velocity. As a result, the mechanical conditions can be optimally adapted to the beam path despite direct coupling.

In an advantageous embodiment, the coupling between the combiner and the movably arranged optical component is realized via a coupling gear. This provides a particularly simple, cost-effective and reliable way to convert the small movement of the movable optical component necessary for the height adjustment of the Eye-Box into the corresponding path around which the combiner must be moved, so that both can be moved by means of an electric or electric motor manual drive can be positioned simultaneously.

In a further advantageous embodiment, the mechanical coupling is done with translation by means of a gear transmission. The required translation over a correspondingly selected number of teeth can be easily realized.

Advantageously, the movement of the components takes place by means of a drive which is directly or indirectly connected to one of the coupled components and / or the coupling. This allows an electronic height adjustment of the head-up display done. This has the particular advantage that the height adjustment can be done automatically in the context of a so-called eye-tracking, so an automatic tracking on the basis of the movements of the eyes. For this purpose, the movement of the eye is detected, electronically converted and converted via the drive into a tracking movement of the optical components of the combiner and the movably arranged optical unit of the projection unit. This is particularly advantageous because of the invention, because according to the invention only a few, lightweight optical components have to be moved to small ways to effect height adjustment of the head-up display, but not the entire head-up display, including electronics. This realization of dynamic tracking opens up the possibility of making the Eyebox smaller and thus makes it possible to dimension the optics components smaller and thus lighter and cheaper.

Alternatively, for a more cost effective version of a head-up display, a manual adjustment may also be realized, e.g. works by means of an adjusting lever without drive unit.

In a particularly advantageous embodiment, a plane mirror is arranged between the projection unit and the combiner as a movably arranged component, which projects the projected image onto the combiner. Both plane mirror and combiner are movable and preferably mounted so that coupled via a coupled movement of only these two components height adjustment of the eye-box to the driver or the seat adjustment is possible without affecting the quality of the image. The components of the projection unit, which are more complicated to adjust and more prone to errors, remain immobile in this advantageous construction. The cover of the head-up display can remain in its global position. Their irradiation with a modified angle of incidence during the movement of the combiner and plane mirror, depending on their thickness, only results in a very slight loss of quality. When installed in different vehicles, but this can be installed according to the nominal angle of incidence so that no losses must be taken. Thus, a particularly great flexibility in terms of installation in different vehicles can be achieved.

In a particularly advantageous embodiment, a so-called triple-notch coating which is specially adapted to the color spectra, ie a coating which reflects the projection unit light projected onto the combiner only in three narrow wavelength ranges, is applied to the reflective concave side of the combiner , This makes it possible to realize a multi-color head-up display, which allows maximum amount of light from the environment to pass through the combiner and still provides a color display image.

The combiner is preferably designed as a freeform surface. This also supports the compact design of the optical projection unit with a large eye box.

It should also be noted that the principle of height adjustment via a coupled movement of movably mounted planar mirror and combiner can also be used effectively in other embodiments of a head-up display. In principle, it would also be conceivable to use another optical element, such as another lens or a Mangin mirror for height adjustment of the eye box, instead of the plane mirror.

Generally, it should be noted that this form of height adjustment can be used particularly advantageously in all vehicles, watercraft and even aircraft.

Further details and advantages of the invention will become apparent from the dependent claims in conjunction with the description of an embodiment which is explained in detail with reference to the drawings. Corresponding components in the figures are identified by the same reference numerals. Show it:

Fig. 1 Schematically an inventive head-up display in a first embodiment, Fig. 2 shows the coupling of plane mirror and combiner by means of coupling gear and

Fig. 3a, b, the coupling of plane mirror and combiner by means of gear transmission.

1 shows a schematic representation of the structure of a head-up display according to the invention, which is installed in a motor vehicle. The head-up display has a projection unit 1 and a combiner unit 2. In the beam path between these two components is a plane mirror 3, which is connected via a coupling gear 4 and an extension 5 with the combiner 2 and a cover 6, which includes the optical unit of the head-up display in the cockpit of the motor vehicle. Projection unit 1, plane mirror 3 and coupling gear 4 are located below the cover 6, the combiner unit 2 is located above the cover in front of the windshield. 7

The projection unit 1 of the head-up display according to the invention has an image generating device 8, which is designed as illuminated by light emitting diodes or other light sources light modulator such as. LCD or DMD or as a self-luminous display. Furthermore, the projection unit 1 has a combination of a first lens 9, a second lens 10 and a manganese mirror 11 arranged between these two lenses 9, 10.

The image to be displayed by the head-up display is generated by means of an LCD 8 illuminated by tricolor LED ^'s . This image to be displayed is displayed via the opti- see elements 9, 10 and 11 of the projection unit 1 shown in an intermediate image 12.

When passing through the plastic lenses 9 and 10, the image is greatly enlarged, so that a large viewing area and a large field of view can be realized, at the same time, an imaging into an intermediate image 12 is made via these lenses 9 and 10. The image field curvature caused in the image in an intermediate image 12 can be compensated for directly by the lenses 9 and 10, since these are formed as positive lenses. However, when using plastic lenses and imaging with a large field of view, this image is subject to severe color aberrations. Therefore, according to the invention, a manganese mirror 11 is arranged between the positive lenses 9 and 10, via which both a folding of the beam path and a correction of the chromatic aberrations caused by the lenses 9 and 10 are undertaken. In order to ensure optimum color aberration, the lenses 9 and 10 and provided as part of the Manginspiegels 11 negative lens made of very similar, preferably the same material. In order to ensure the correction of the color longitudinal and lateral chromatic aberration, the Manginspiegel 11 was positioned so that it lies in the aperture. As a result, further EIe- elements, for. B. be avoided with other dispersions or diffractive optical elements for color correction. The color correction is ensured solely by the combination of positive lens 9 for the telecenthe image of the image produced on the display 8, the Mangin mirror 11 with its negative lens and another positive lens 10 arranged in the beam path after the Mangin mirror. This is done essentially by the selection of similar or identical materials for the lenses and the selected position of the Manginspiegels 11. Only then is it possible to produce a multi-color system with a large field of view and such a large eye-box. The intermediate image 12 is projected via a plane mirror 3 and a combiner 2 in a virtual image, where it can be viewed by the driver of the motor vehicle. The Combiner 2 is relatively strongly curved, it has a high refractive power. This makes it possible to detect the rays running from the edge of the eye box to the edge of the virtual image without having to use extremely large optical elements in the projection unit 1. The Combiner 2 is designed as a freeform surface and coated several times. Double-image suppression, reflectivity and transmission are ensured by this coating. In particular, mention should be made here of the so-called triple-notch coating, a coating which permits increased reflectivity with constant average transmission for three specific wavelength ranges. This specially adapted to the color spectra coating is mounted on the reflective concave side of the combiner 2.

Both plane mirror 3 and combiner 2 are movably mounted and connected via a coupling gear 4 and an extension 5 of the same. About a movement of the linkage 4 by means of a drive unit, not shown, the image or the eye box of the observer is adjusted in height and can thus be adapted to the seat adjustment or the size of the viewer. So that the combiner 2 does not swing out of the beam path during the movement around the small angle range, the plane mirror 3 must be turned at half the angular speed. In this case, the combiner 2 and the plane mirror 3 should rotate about the same axis, which should preferably lie on the surface of the plane mirror 3. This is made possible by the coupling gear 4 shown in FIG. A multi-link coupling gear 4 is connected to the plane mirror 3 and moves over an extension 5 also not seen in this figure combiner 2. For this purpose, a gear member 41 is fixedly connected to the plane mirror 3, another gear member 42 with the extension of the 5. The Fulcrum 42 is as fixed as fulcrum 44. All other fulcrums are movable and can change their position. The joint- member 45, which motivates the movement of the plane mirror 3 is only half as long as the hinge member 46, which causes the movement of the combiner 2. This ensures that the combiner 2 is always rotated by twice the angular range of the plane mirror 3, so that the beam incidence angle does not change. The glass cover 6 is not moved in the height adjustment. She can stay in her position.

A further embodiment for the translation of the movement in the coupling of combiner 2 and plane mirror 3 is shown in FIGS. 3a and in a slightly enlarged view in FIG. 3b. The rotational movement of the plane mirror 3, is effected via a plane mirror gear 131, which is connected to the plane mirror 3. This plane mirror gear 131 is rigidly connected to a combiner gear wheel 132 which moves the extension 5 for coupling the combiner 2 to the plane mirror 3. As a result, the movably arranged combiner 2 experiences a pivoting movement. The gears 131 and 132 are driven by drive gears 133 and 134, which engage in the corresponding teeth and which are themselves rotated by an unillustrated axially acting drive. The number of teeth of the tooth edges 131 and 132 determines the gear ratio.

LIST OF REFERENCE NUMBERS

1 projection unit

2 combiner unit

3 plane mirror

4 coupling gear

5 extension

6 cover

7 windshield

8 Imaging device

9 first lens

10 second lens

11 Mangin levels

12 intermediate image

13 gear transmission

41 joint member

42 joint member

43 fixed point

44 fixed point

45 Short joint

46 Long joint

131 plane mirror gear

132 Combiner gear

133 drive gear

134 drive gear

Claims

claims

1. Head-up display in particular for a motor vehicle with a projection unit (1) for generating a virtual image wherein at least one component (3) of the projection unit (1) is movably arranged to ensure a vertical offset of the virtual image, characterized in that in the beam path after the projection unit (1), a combiner (2) for viewing the virtual image is arranged, wherein the combiner (2) is also movably mounted.

2. Head-up display according to claim 1, characterized in that the movement of the movably arranged component (3) of the projection unit (1) and the combiner (2) is coupled.

3. Head-up display according to claim 2, characterized in that the movable arranged component (3) of the projection unit (1) and the combiner (2) are mechanically coupled.

4. Head-up display according to claim 1 or 2, characterized in that the movably arranged component (3) of the projection unit (1) and the combiner (2) have the same rotational or pivot axis.

5. Head-up display according to claim 4, characterized in that the common axis lies on the surface of the movably arranged component (3) of the projection unit (1).

6. Head-up display according to claim 2, characterized in that the translation of the coupling, a movement of the movable arranged inventory partly (3) of the projection unit (1) by half the angular velocity of the combiner (2).

7. Head-up display according to claim 2, characterized in that the coupling unit (4, 5) has a coupling gear (4).

8. Head-up display according to claim 2, characterized in that the coupling unit (4, 5) has a gear transmission (13).

9. Head-up display according to claim 1 or 2, characterized in that a drive unit for moving the movably arranged component (3) of the projection unit (1) and the combiner (2), with the component (3), the combiner (2 ) and / or the coupling unit (4, 5) is connected.

10. Head-up display according to claim 9, characterized in that the drive unit is coupled with a sensor for dynamically tracking the movements of the eye.

11. Head-up display according to claim 1, 2, 4 or 9, characterized in that the movable component (3) of the projection unit (1) is a pivotally mounted plane mirror (3).

12. Head-up display according to claim 1, characterized in that the combiner (2) has a partially reflecting concave side, on which the rays are reflected for the virtual image, which for three wavelengths a higher

Has reflectivity as on the convex side.