Projection display and method for projecting an overall image

Patent metadata

Field	Value
Publication number	US-9746673-B2
Application number	US-201414500122-A
Country	US
Kind code	B2
Filing date	Sep 29, 2014
Priority date	Mar 29, 2012
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A projection display includes an imager for displaying sub-images in a two-dimensional distribution of sub-areas of the imager and a projection optics array with a two-dimensional distribution of projection optics. The projection optics array is configured to superimpose projections of the sub-images to an overall image in an image plane such that a mutual area overlap of the projections of the sub-images in the image plane in pairs results, which is between 0.1 and 0.8 for all pairs. Here, the projection display is implemented such that the overall image is a virtual overall image.

First claim

The invention claimed is:

1. Projection display comprising:
an imager for displaying sub-images in a two-dimensional distribution of sub-areas of the imager;
a projection optics array with a two-dimensional distribution of projection optics implemented to superimpose projections of sub-images to an overall image in an image plane such that a mutual area overlap of the projections of the sub-images in the image plane in pairs results, which is between 0.1 and 0.8 for all pairs;
wherein the projection display is implemented such that the overall image is a virtual overall image.

2. Projection display according to claim 1 , wherein the projection optics array is implemented to superimpose projections of the sub-images to the overall image in the image plane such that a central tendency of a distribution of the mutual area overlap of the projections of the pairs is between 0.2 and 0.8.

3. Projection display according to claim 1 , wherein projections overlapping in the image plane are also adjacent to one another in the projection optics.

4. Projection display according to claim 1 , wherein the projection optics are each allocated to a sub-area of the imager, wherein a pitch of the projection optics is equal to a pitch of the sub-areas of the imager allocated to the projection optics.

5. Projection display according to claim 1 , wherein the projection optics array further comprises a field lens downstream of the two-dimensional distribution of the projection optics in the projection direction, in order to direct the projections of the sub-images into a pupil of a user of the projection display, such that the image plane is a virtual image plane, wherein the imager and the two-dimensional distribution of the projection optics are arranged between the same and the field lens.

6. Projection display according to claim 5 , wherein the field lens is a Fresnel lens.

7. Projection display according to claim 1 , wherein the projection optics are each allocated to sub-areas of the imager, wherein the imager is implemented to display, with increasing distance to an optical axis of the projection optics array in the sub-areas of the imager allocated to the projection optics, sub-images which are increasingly decentered parts of an overall image to be displayed which is provided to the imager, wherein the optical axis runs essentially through a center of the two-dimensional distribution of sub-areas of the imager.

8. Projection display according to claim 1 , wherein the two-dimensional distribution of the projection optics comprises a plurality of plano-convex or biconvex projection lenses.

9. Projection display according to claim 1 , wherein the projection optics array comprises a plurality of two-dimensional distributions of projection optics stacked above one another in the projection direction, wherein the plurality of two-dimensional distributions of projection optics are implemented to correct an aberration of the projection optics array.

10. Projection display according to claim 1 , wherein the imager is implemented to display each of the sub-images with an image brightness which continuously decreases towards the edge of the sub-image, so that artefacts in an overlapping area of the projections in the image plane are suppressed or prevented.

11. Projection display according to claim 1 , wherein the two-dimensional distribution of the projection optics comprises a plurality of lens segments which are differently decentered with respect to their aperture, wherein the plurality of lens segments is implemented to direct the projections of the sub-images into a pupil of a user of the projection display.

12. Projection display according to claim 1 , wherein the imager is implemented to increase or decrease distances between centers of the sub-images to adjust a projection distance.

13. Projection display according to claim 1 , wherein the imager is implemented to displace all sub-images evenly in the direction of a lateral extension of the two-dimensional distribution of the sub-areas of the imager, wherein the even displacement of the sub-images is adjustable in dependence on a measured position of an eyeball of a user with respect to an optical axis of the projection optics array.

14. Projection display according to claim 1 , wherein the imager is a transmissive or a reflective imager.

15. Method for projecting an overall image with a projection display, comprising:
displaying sub-images with an imager in a two-dimensional distribution of subareas of the imager;
superimposing projections of the sub-images to an overall image in an image plane by a projection optics array with a two-dimensional distribution of projection optics such that a mutual area overlap of the projections of the sub-images in the image plane in pairs results, which is between 0.1 and 0.8 for all pairs;
wherein the projection display is implemented such that the overall image is a virtual overall image.

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• Schreiber Peter
• Sieler Marcel
• Kraus Matthias

Classifications

• G02B2027/0152

  involving arrangement aiming to get lighter or better balanced devices · CPC title

• G02B27/0101

  characterised by optical features (G02B27/0172 takes precedence) · CPC title

• G02B2027/015

  involving arrangement aiming to get less bulky devices · CPC title

• G02B27/017 Primary

  Head mounted · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title