PROJECTION DISPLAY AND USE THEREOF

• US 20110228231A1
• Filed: 06/11/2010
• Published: 09/22/2011
• Est. Priority Date: 06/15/2009
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Foerster, Erik, Sieler, Marcel, Schreiber, Peter
• Granted Patent: US 8,777,424 B2
• Time in Patent Office: Days
• US Class Current: 353/31
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G03B 21/13 Projectors for producing special effects at the edges of picture, e.g. blurring
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026

Abstract

The invention relates to a projection display having at least one light source and also regularly-disposed optical channels. The optical channels comprise at least one field lens, to which respectively one object structure to be imaged and also at least one projection lens are assigned. The distance of the projection lenses from the assigned object structures corresponds to the focal distance of the projection lenses whilst the distance of the object structures to be imaged from the assigned field lens is chosen such that a Köhler illumination of the assigned projection lens is made possible. Then the individual projections are superimposed to form the total image.

Claims

1. Projection display having at least one light source and regularly-disposed optical channels, comprising at least one field lens, to which respectively one object structure to be imaged and also at least one projection lens are assigned, the distance of the projection lenses from the assigned object structures corresponding to the focal distance of the projection lenses and the distance of the identical object structures to be imaged from the assigned field lens is chosen such that a Kö

hler illumination of the assigned projection lens is made possible and the individual projections being superimposed to form an actual total picture on a screen or a virtual total picture.

2. Projection display according to claim 1, characterised in that the arrangement of the optical channels has a further common field lens for compensating for the illumination telecentricity.

3. Projection display according to claim 1, characterised in that the optical channels have optical elements adapted with respect to the channels, in particular concentrators for masking the inactive regions between the field lenses.

4. Projection display according to claim 1, characterised in that the object structures have a predistortion, with respect to the channels, for correction of a distortion.

5. Projection display according to claim 1, characterised in that the projection lenses remote from the axes have a greater focal distance for correction of a lack of focus due to the larger image distance of these channels.

6. Projection display according to claim 1, characterised in that the projection lenses remote from the axes are adapted, with respect to sagittal and tangential focal distance, by being designed as anamorphotic lenses, e.g. elliptical lenses, with respect to the channels, for compensation of astigmatism.

7. Projection display according to claim 1, characterised in that at least one optical channel has at least two projection lenses for aberration correction.

8. Projection display according to claim 1, characterised in that at least a part of the optical channels has object structures buried below the field lenses in the form of a lithographically-structured object mask.

9. Projection display according to claim 1, characterised in that the object structures are disposed at least partially on a curved surface, in particular on the field lens surface, in order to level out the image field.

10. Projection display according to claim 1, characterised in that the projection display has a constructional length in the range of 0.5 to 10 mm.

11. Projection display according to claim 1, characterised in that the projection lenses have a reduced average distance relative to the object structures, as a result of which the optical axes of the outer optical channels are tilted.

12. Projection display according to claim 1, characterised in that the projection display is subdivided into three segments which are assigned respectively to a primary colour part, as a result of which a full colour projection is made possible.

13. Projection display according to claim 12, characterised in that the number of lenses assigned to the respective primary colour and object structures is chosen such that a white balance which compensates for the spectral properties of the source or of the source and colour filters is made possible with simultaneous maximisation of the image brightness.

14. Projection display according to claim 1, characterised in that the object structure is produced by a digital imager, in particular an LCD display or an OLED display.

15. Projection display according to claim 1, characterised in that the projection display has a unit for electronic offset of the individual images, as a result of which the projection distance is controlled.

16. Projection display according to the preceding claim, characterised in that the projection display has a unit for measuring the distance from the screen, which, in combination with the unit for the electronic offset, enables electronic tracking of the projection distance.