Projection type image display apparatus and display device

• US 20050099116A1
• Filed: 11/30/2004
• Published: 05/12/2005
• Est. Priority Date: 07/31/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Koide, Jun
• Granted Patent: US 7,090,356 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3138 using arrays of modulated light sources electroluminescent display devices G09G3/30

Abstract

A projection type image display apparatus includes an electroluminescence element which has a plurality of pixels that can each emit modulated light, a projection optical system which projects the light emitted from each of the pixels in the electroluminescence element onto an object to display an image, and a sensor which detects brightness of ambient light that illuminates the object. A controller controls brightness of the light emitted from the electroluminescence element based on the brightness of the ambient light.

Claims

1-7. -7. (canceled).

8. A projection type image display apparatus comprising:

an electroluminescence element which has a plurality of pixels that can each emit modulated light;

a projection optical system which projects the light emitted from each of the pixels in the electroluminescence element onto an object to display an image;

a sensor which detects brightness of ambient light that illuminates the object; and

a controller which controls brightness of the light emitted from the electroluminescence element based on the brightness of the ambient light.

9. The projection type image display apparatus according to claim 8, wherein the controller reduces overall maximum brightness of the light emitted from the electroluminescence element in such a way that the amount of light projected onto the object is reduced as the brightness of the ambient light decreases.

10. The projection type image display apparatus according to claim 8, wherein the controller corrects a distribution of maximum brightness of the light emitted from each pixel of the electroluminescence element so that the amount of light projected onto the object is distributed uniformly in the entire projection area as the brightness of the ambient light decreases.

11. The projection type image display apparatus according to claim 9, wherein the controller controls the overall maximum brightness of the light emitted from the electroluminescence element by modulating a peak current value or a current pulse time width supplied to the electroluminescence element.

12. The projection type image display apparatus according to claim 10, wherein the controller corrects the distribution of the maximum brightness of the light emitted from each of the pixels by modulating a current pulse time width or peak current value supplied to each pixel of the electroluminescence element.

13. The projection type image display apparatus according to claim 8, wherein the electroluminescence element comprises emission pixels of three primary colors arranged in repetitive matrix form and displays an additive color mixture image.

14. The projection type image display apparatus according to claim 8, further comprising:

three electroluminescence elements which emit three primary colors respectively; and

a wavelength-combining element which includes a dichroic waveband separating film and combines color beams emitted from the three electroluminescence elements,

wherein the light combined by the wavelength-combining element is projected onto the object through the projection optical system to display an additive color mixture image.

15. The projection type image display apparatus according to claim 8, wherein, in the electroluminescence element, excitons are formed by injecting charge carriers into a luminescent layer which has a material including an organic fluorescent material, and modulation pixels that emit light by recombination of the excitons are arranged two-dimensionally.

16. The projection type image display apparatus according to claim 15, wherein a resonance structure of photons generated is formed of a charge carrier injection electrode film and a light reflecting film provided on the outer surface of the electrode film provided on the outer surface of the electrode film in the electroluminescence element.

17. An image display system comprising:

the projection type image display apparatus according to claim 8;

and

a screen onto which the projection type image display apparatus projects an image,

wherein an image projected on the screen is recognized by an observer by means of diffused light that has been reflected by the screen and has predetermined directivity.

18. An image display system comprising:

the projection type image display apparatus according to claim 8;

and

a screen onto which the projection type image display apparatus projects an image,

wherein an image projected on the screen is recognized by an observer by means of diffused light that has been transmitted through the screen and has predetermined directivity.

19. A display device comprising:

an electroluminescence element which has a plurality of pixels that can each emit modulated light;

a display which displays an image by using the light emitted from each pixel in the electroluminescence element;

a sensor which detects brightness of ambient light that illuminates the display; and

a controller which controls brightness of the light emitted from the electroluminescence element based on the brightness of the ambient light.