Projection display unit

• US 6,416,186 B1
• Filed: 08/21/2000
• Issued: 07/09/2002
• Est. Priority Date: 08/23/1999
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nakamura, Nobutatsu
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/642,093
• Time in Patent Office: 687 Days
• Field of Search: 353/69, 353/70, 353/122, 348/745, 348/746, 348/806, 345/647, 345/643
• US Class Current: 353/69
• CPC Class Codes: G03B 21/006 using LCD's
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A projection display unit, in which a distortion of an image is corrected even when the image is projected from an arbitrary direction, further which can correct a distortion caused by that an image is projected on a screen surface having an irregular surface or a free surface, is provided. The projection display unit provides an image inputting means to which an original image is inputted, a screen surface obtaining means for obtaining a three dimensional shape of a screen surface by calculating an azimuth angle, a tilt angle, and a distance of the screen surface for the projection display unit by using the normal line vector of the screen surface, an image correcting means for executing an inclination correction and a zooming in/out correction for the original image corresponding to the three dimensional shape of the screen surface, and an image outputting means for outputting the corrected image as a projecting image.

Claims

1. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

a screen surface obtaining means for obtaining a three dimensional shape of a screen surface by calculating an azimuth angle, a tilt angle, and a distance of said screen surface for said projection display unit by using the normal line vector of said screen surface;

an image correcting means for executing an inclination correction and a zooming in/out correction for said original image corresponding to said three dimensional shape of said screen surface; and

an image outputting means for outputting the corrected image as a projecting image.

2. A projection display unit in accordance with claim 1, wherein:

said inclination correction makes said original image rotate corresponding to the inclination of said screen surface, and also makes the size of said original image change corresponding to the ratio between said distance of said screen surface and a focal distance of lens of said projection display unit, and makes the coordinate of said original image projected on a tentative reference surface change corresponding to said distance and said inclination of said screen surface; and

said zooming in/out correction makes the coordinate of said original image change corresponding to the ratio between the distance from the center of said projection display unit to a reference surface and the distance from the center of said projection display unit to said tentative reference surface.

3. A projection display unit in accordance with claim 1, further comprising:

a projection controlling means which calculates said focal distance of said lens of said projection display unit corresponding to said distance of said screen surface calculated at said screen surface obtaining means and controls the focus in said image outputting means.

4. A projection display unit in accordance with claim 3, wherein:

said inclination correction is executed by said focal distance calculated at said projection controlling means.

5. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

a screen surface obtaining means for obtaining a three dimensional shape of a screen surface by calculating an azimuth angle, a tilt angle, and a distance of said screen surface for said projection display unit by using the normal line vector of said screen surface;

a virtual approximate screen surface generating means for generating a virtual approximate screen surface by using said three dimensional shape of said screen surface calculated at said screen surface obtaining means;

a perspective projection means for calculating a corrected image by orthographic projection of a three dimensional image which is obtained by that a projection simulation is applied to said inputted original image on said virtual approximate screen surface by a perspective projection process; and

an image outputting means for outputting the corrected image as a projecting image.

6. A projection display unit in accordance with claim 5, wherein:

said virtual approximate screen surface is obtained by that the coordinate of said screen surface is rotated by the inclination of said screen surface, and a directional vector of said coordinate from the center of said projection display unit is obtained, and an angle between said directional vector and an optical axis of said projection display unit is obtained, and a process for calculating three dimensional coordinate of the position of said virtual approximate screen surface of said coordinate is applied to all coordinates, and a three dimensional polygon connected each coordinate of said virtual approximate screen surface is generated.

7. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

an image outputting means which outputs an image that said original image is processed as a projecting image;

a projection controlling means which changes over an image inputting to said image outputting means;

a pattern image generating means which generates pattern images and outputs said pattern images;

a screen surface obtaining means which obtains a shape of a screen surface by that by using said pattern images and images on said screen surface at the time when said pattern images are inputted to said image outputting means and are taken by a camera, and by obtaining three dimensional coordinates of the positions projected said pattern images by using a triangulation method with making the coordinate of said projection display unit correspond to the coordinate of camera images being said pattern images taken; and

an image correcting means which executes an inclination correction and a zooming in/out correction for said inputted original image corresponding to said shape of said screen surface and inputs said corrected image to said image outputting means.

8. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

an image outputting means which outputs an image that said original image is processed as a projecting image;

a projection controlling means which has data of the position and direction of said projection display unit in a projection room and controls said data;

a projection room inside shape data base in which shape data inside the projection room are stored;

a screen surface obtaining means which obtains a shape of a screen surface by converting said shape data inside projection room obtained from said projection room inside shape data base corresponding to said position and direction data of said projection display unit; and

an image correcting means which executes an inclination correction and a zooming in/out correction for said inputted original image corresponding to said shape of said screen surface and inputs said corrected image to said image outputting means.

9. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

an image outputting means which outputs an image that said original image is processed as a projecting image;

a marker detecting means for detecting markers provided inside a projection room;

a projection room inside shape data base in which shape data inside the projection room are stored;

a screen surface obtaining means which obtains a shape of a screen surface by converting said shape data inside projection room obtained from said projection room inside shape data base corresponding to said position and direction data of said projection display unit based on a detected result at said marker detecting means; and

an image correcting means which executes an inclination correction and a zooming in/out correction for said inputted original image corresponding to said shape of said screen surface and inputs said corrected image to said image outputting means.

10. A projection display unit, comprising:

an image inputting means to which an original image is inputted;

an image outputting means which outputs an image that said original image is processed as a projecting image;

a marker detecting means for detecting markers provided at said projection display unit itself;

a projection room inside shape data base in which shape data inside the projection room are stored;

a screen surface obtaining means which obtains a shape of a screen surface by converting said shape data inside projection room obtained from said projection room inside shape data base corresponding to said position and direction data of said projection display unit based on a detected result at said marker detecting means; and

an image correcting means which executes an inclination correction and a zooming in/out correction for said inputted original image corresponding to said shape of said screen surface and inputs said corrected image to said image outputting means.