Projection display and method for displaying an overall image for projection free-form surfaces or tilted projection surfaces

Patent metadata

Field	Value
Publication number	US-9247222-B2
Application number	US-201314083399-A
Country	US
Kind code	B2
Filing date	Nov 18, 2013
Priority date	May 18, 2011
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A projection display with an imaging system is described, which is implemented to generate individual images in a distribution, such as a two-dimensional distribution, of sub-areas of an imaging plane of the imaging system, and a multi-channel optics that is configured to map one allocated individual image or one allocated sub-area of the imaging system each per channel, such that the mapping of the individual images is at least partly superimposed to an overall image in a projection surface, wherein the projection surface is a non-planar free-form surface, such as a curved surface, and/or tilted with respect to the imaging plane, and the imaging system is implemented such that constellations of points in the sub-images, each superimposed in a respective common point in the overall image by the multi-channel optics, differ depending on what distance the respective common point in the overall image has to the multi-channel optics.

First claim

The invention claimed is:

1. A projection display comprising
an imaging system that is implemented to generate individual images in a distribution of sub-areas of an imaging plane of the imaging system; and
a multi-channel optics that is configured to map one allocated sub-area of the imaging system each per channel, such that the mapping of the individual images is superimposed to an overall image in a projection surface which is a non-planar free-form surface or tilted with respect to the imaging plane,
wherein
the imaging system is implemented as a fixed mask fixedly forming the individual images at the sub-areas so that the projection surface is located at a fixed position relative to the projection display, with the fixed mask being configured so that the individual images are mutually distorted relative to each other such that
or
the imaging system is implemented as a digital imaging system configured to reproduce versions of an input image to be displayed as the individual images, the imaging system being configured so as to mutually distort the images relative to each other in a fixed manner so that the projection surface is located at a fixed position relative to the projection display, and such that
or
the imaging system is implemented as a digital imaging system configured to reproduce versions of an input image to be displayed as the individual images, the imaging system being configured so as to mutually distort the images relative to each other in a manner adaptive to a relative position of the projection surface relative to the projection display such that
constellations of points in the individual images, each superimposed in a respective common point in the overall image by the multi-channel optics, differ depending on what distance the respective common point in the overall image has to the multi-channel optics.

2. The projection display according to claim 1 , wherein the multi-channel optics comprises a two-dimensional assembly of projection optics in a projection optics plane essentially parallel to the imaging plane, wherein the projection optics assembly is configured to map one allocated individual image of the imaging system each along a respective optical axis in the direction of the projection surface, such that the mappings of the individual images are superimposed to the overall image in the projection surface.

3. The projection display according to claim 2 , wherein the projection optics comprises decentration with respect to the allocated sub-areas, wherein a center pitch of the projection optics is smaller than a center pitch of the allocated sub-areas, so that the overall image superimposed in the projection surface is real.

4. The projection system according to claim 2 , wherein the projection optics comprises decentration with respect to the allocated sub-areas, wherein the center pitch of the projection optics is larger than or equal to the center pitch of the allocated sub-areas, so that the overall image superimposed in the projection surface is virtual.

5. The projection display according to claim 2 , wherein the projection optics is centered with respect to the allocated sub-areas and has a collimating effect.

6. The projection display according to claim 3 , wherein the projection optics assembly further comprises an overall lens that is downstream with respect to the two-dimensional assembly of projection optics and cooperates with the two-dimensional assembly of projection optics that is implemented to refocus collimated beams from the projection optics in a focal plane of the overall lens, wherein the projection optics are centered with respect to the allocated sub-areas and have a collimating effect, or to focus divergent/convergent beams from the projection optics in an effective focal plane resulting by decentration between the projection optics on the one hand and the sub-areas on the other hand and focusing by the downstream overall lens.

7. The projection display according to claim 6 , wherein the overall lens is implemented as optics with variable focal length, so that an average projection distance can be adjusted.

8. The projection display according to claim 7 , wherein the optics with variable focal length is a zoom objective or a liquid lens.

9. The projection display according to claim 2 , wherein each projection optics comprises a lens vertex decentered with respect to the aperture of the respective projection optics, wherein a center pitch of the lens vertex is larger or smaller than the center pitch of the allocated sub-areas, so that the lenses effect a projection of the individual image of the respective sub-area along optical axes running divergently or convergently.

10. The projection display according to claim 2 , wherein a distance between the sub-areas and the respective projection optics essentially corresponds to a focal length of the respective projection optics.

11. The projection display according to claim 2 , wherein a distance between the sub-areas and the respective projection optics essentially corresponds to a focal length of the respective projection optics, but such that the projection lenses remote from the axis have a larger focal length for correcting a defocus due to the larger image distance of these channels.

12. The projection display according to claim 1 , wherein the imaging system is further implemented such that the constellations additionally differ depending on the solid angle region in which, seen from the multi-channel optics, the respective common point lies, in order to compensate mapping errors of the multi-channel optics.

13. The projection display according to claim 12 , wherein the imaging system is further implemented such that the constellations differ additionally depending on the solid angle region in which, seen from the multi-channel optics, the respective common point lies such that mapping errors of the multi-channel optics can be compensated individually for each channel.

14. The projection display according to claim 1 , wherein the imaging system is implemented such that the difference between the constellations depending on the distance of the respective common point in the overall image to the multi-channel optics is reflected mainly in a centric extension between the constellations, so that first constellations of points in the individual images, each superimposed by the multi-channel optics in a respective common point in the overall image that is less distant to the multi-channel optics than a respective common point in the overall image where points of second constellations in the individual images are superimposed by the multi-channel optics assembly, are laterally more extended with respect to the second constellations.

15. The projection display according to claim 1 , wherein the imaging system is implemented, for homogenizing the illuminance across the overall image, to vary the sum of the luminosities of the points of the constellations in the imaging plane depending on the distance of the respective common point in the overall image to the multi-channel optics to which the points of the respective constellations are superimposed by the multi-channel optics, namely by luminosity variation of the points and/or variation of the number of sub-areas contributing a respective point to the respective constellation.

16. The projection display according to claim 15 , wherein the imaging system is implemented such that the luminosity variation of the points and/or the variation of the number of sub-areas contributing a respective point to the respective constellation is such that points of sub-area

Assignees

• Fraunhofer Ges Forschung

Inventors

• Sieler Marcel
• Schreiber Peter

Classifications

• H04N9/3147

  Multi-projection systems (video walls G06F3/1446) · CPC title

• G03B21/001 Primary

  Slide projectors · CPC title

• G03B21/142

  Adjusting of projection optics · CPC title

• G03B21/147 Primary

  Optical correction of image distortions, e.g. keystone · CPC title

• G03B21/005

  Projectors using an electronic spatial light modulator but not peculiar thereto · CPC title