IP Library Granted Patent US 11,156,825
Granted Patent B2
US 11,156,825 · App. 16/316,323 · Granted Oct 26, 2021

Projector

Inventor: Atsushi Kato (Tokyo, JP)
Assignee: SHARP NEC DISPLAY SOLUTIONS, LTD.
G02B26/008G02F1/1335G03B21/204G03B21/2066
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Quick Facts
Patent No.
US 11,156,825
App. No.
16/316,323
Granted
Oct 26, 2021
Kind
B2
Abstract

A projector includes: a phosphor wheel that, in response to the irradiation of excitation light that is used as the first illumination light, generates fluorescence that contains second illumination light and third illumination light and emits the excitation light and fluorescence in opposite directions; first to third image display elements that are provided corresponding to the first to third illumination light; a first illumination optical system that guides the excitation light that was emitted from the phosphor wheel to the first image display element; and a second illumination optical system and third illumination optical system that guide the second illumination light and third illumination light that are contained in the fluorescence emitted from the phosphor wheel to the second image display element and to the third image display element. The lengths of the optical paths of the first, second, and third illumination optical systems are the same.

Claims (13)

1. A projector comprising:

a phosphor wheel that, in response to the irradiation of excitation light that is used as first illumination light, emits fluorescence that contains second illumination light and third illumination light and that emits said excitation light and said fluorescence in mutually opposite directions;

first to third image display elements that are provided corresponding to said first to third illumination light;

a first illumination optical system that guides excitation light that is emitted from said phosphor wheel to said first image display element; and

a second illumination optical system and third illumination optical system that guide said second illumination light and third illumination light that are contained in said fluorescence emitted from said phosphor wheel to said second image display element and said third image display element;

wherein:

the lengths of the optical paths of said first to third illumination optical systems are equal.

2. The projector according to claim 1 , wherein said phosphor wheel has: a substrate that transmits said excitation light, and a phosphor that is fixed to the substrate and that emits said fluorescence in response to the irradiation of said excitation light.

3. The projector according to claim 1 , further comprising a reflecting film that is formed on the side of said phosphor wheel on which said phosphor is not formed and that reflects said fluorescence and transmits said excitation light.

4. The projector according to claim 1 , wherein said excitation light is blue light, said fluorescence is yellow light, said second illumination light is green light, and said third illumination light is red light.

5. The projector according to claim 1 , wherein said first to third image display elements comprise transmissive liquid crystal panels.

6. The projector according to claim 1 , wherein said first to third image display elements comprise reflective liquid crystal panels.

7. The projector according to claim 1 , wherein said first to third image display elements comprise Digit Micromirror Devices (DMDs).

Assignments (3)
MERGER Recorded Jun 26, 2026
From: SHARP NEC DISPLAY SOLUTIONS, LTD.
To: SHARP KABUSHIKI KAISHA
Reel/Frame 075830/0109 →
CHANGE OF NAME Recorded Sep 29, 2021
From: NEC DISPLAY SOLUTIONS, LTD.
To: SHARP NEC DISPLAY SOLUTIONS, LTD.
Reel/Frame 057669/0830 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 9, 2019
From: KATO, ATSUSHI
To: NEC DISPLAY SOLUTIONS, LTD.
Reel/Frame 047943/0864 →
Continuity (1)
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