Multilayered fluorescent screens for scanning beam display systems
View Patent ↗Fluorescent screens and display systems and devices based on such screens using at least one excitation optical beam to excite one or more fluorescent materials on a screen which emit light to form images. The fluorescent materials may include phosphor materials and non-phosphor materials such as quantum dots.
1. A display screen, comprising:
a fluorescent layer comprising a plurality of parallel fluorescent stripes, the fluorescent layer absorbing excitation light to emit visible light, wherein the excitation light and the visible light are of different wavelengths, and wherein adjacent fluorescent stripes in the plurality of parallel florescent stripes emit visible light of different colors and are separated by a respective stripe divider;
an entrance layer on a first side of the fluorescent layer to receive the excitation light and to direct the excitation light to the fluorescent layer;
a first filter layer on a second side of the fluorescent layer opposite to the first side, the first filter layer formed of a material that transmits the visible light and uniformly attenuates the visible light over a spectral range of the visible light; and
a dielectric layer in contact with each respective stripe divider separating a respective pair of adjacent florescent stripes in the plurality of parallel fluorescent stripes, wherein the dielectric layer is spaced from the fluorescent layer to define a gap between the dielectric layer and the fluorescent layer.
2. The display screen as in claim 1 , wherein:
the first filter layer further blocks transmission of the excitation light.
3. The display screen of claim 1 , wherein:
the first filter layer includes an optical neutral density filter that transmits and uniformly attenuates the visible light over the spectral range of the visible light.
4. The display screen as in claim 3 , wherein:
the first filter layer further includes an excitation blocking layer that substantially blocks the excitation light.
5. The display screen as in claim 3 , wherein:
the optical neutral density filter further blocks transmission of the excitation light.
6. The display screen as in claim 1 , further comprising:
a second filter layer on the second side of the fluorescent layer opposite to the first side, the second filter layer blocking transmission of the excitation light and transmitting the visible light.
7. The display screen as in claim 1 , wherein:
the entrance layer comprises a prismatic layer which includes a plurality of prism elements.
8. The display screen as in claim 1 , wherein:
the entrance layer comprises a dielectric layer with a flat surface to receive the excitation light.
9. The display screen as in claim 1 , wherein:
the entrance layer comprises a Fresnel lens layer.
10. The display screen as in claim 1 , wherein:
the respective stripe divider has side walls that are reflective and opaque to the visible light emitted by the adjacent fluorescent stripes.
11. The display screen as in claim 10 , wherein:
the respective stripe divider comprises a white paint that is optically reflective and opaque.
12. The display screen as in claim 1 , wherein:
a first florescent stripe of the adjacent florescent stripes is of a first florescent material emitting visible light of a first color, and a second florescent stripe of the adjacent florescent stripes is of a second florescent material emitting visible light of a second color different from the first color.
13. The display screen as in claim 12 , wherein:
the first florescent material and the second florescent material are different colored phosphors.
14. The display screen of claim 1 , wherein:
the fluorescent layer includes a continuous florescent film that emits white light when excited by the excitation light;
the fluorescent layer further includes, on the second side of the fluorescent layer, a plurality of parallel, colored filter stripes located on the continuous florescent film; and
each of the plurality of parallel, colored filter stripes, in conjunction with a respective portion of the continuous fluorescent film that directly faces the colored filter stripe, forms a respective one of the plurality of parallel florescent stripes and emits visible light of a respective color.
15. The display screen of claim 14 , wherein:
the continuous florescent film is made of a mixture of different colored phosphors.
16. The display screen of claim 1 , wherein:
the respective stripe divider has an optically reflective side that faces the entrance layer and reflects the excitation light.
17. The display screen of claim 1 , wherein:
the respective stripe divider has an optically absorbent side that faces the first filter layer and absorbs visible ambient light.