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 plurality of screen layers forming a planar stack, the screen layers including:
a fluorescent layer comprising a plurality of parallel fluorescent stripes, wherein the plurality of parallel fluorescent stripes each absorbs excitation light and emits visible light of a respective color, and wherein adjacent fluorescent stripes emit visible light of different respective colors;
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; and
a first filter layer on a second side of the fluorescent layer opposite to the first side
wherein the first filter layer comprises a plurality of parallel, first filter stripes, each first filter stripe is aligned with a corresponding fluorescent stripe along a direction perpendicular to the screen layers, the first filter stripe transmits visible light of the respective color emitted by the corresponding fluorescent stripe and absorbs visible light of the respective colors emitted by other fluorescent stripes adjacent to the corresponding fluorescent stripe,
wherein the fluorescent layer further includes a plurality of first stripe dividers, each first stripe divider being located between a pair of adjacent fluorescent stripes in the florescent layer and has side walls that are reflective and opaque, and
wherein the first filter layer further includes a plurality of second stripe dividers, each second stripe divider being located between a pair of adjacent filter stripes in the filter layer and has side walls that are reflective and opaque.
2. The display screen as in claim 1 , wherein:
a first florescent stripe of the adjacent florescent stripes is made of a first colored phosphor, and a second florescent stripe of the adjacent florescent stripes is made of a second, different colored phosphor.
3. 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 a plurality of parallel, second filter stripes located on the continuous florescent film; and
each of the plurality of second filter stripes, in conjunction with a respective portion of the continuous fluorescent film that directly faces the second filter stripe, forms a respective one of the plurality of parallel florescent stripes.
4. The display screen of claim 3 , wherein:
the continuous florescent film is made of a mixture of different colored phosphors.
5. The display screen as in claim 1 , wherein:
each first stripe divider comprises a white paint that is optically reflective and opaque.
6. The display screen as in claim 5 , wherein:
the white paint comprises a mixture of TiO2 or barium sulfate and a resin.
7. The display screen of claim 1 , wherein:
each second stripe divider has an optically reflective side that faces the entrance layer and reflects the excitation light.
8. The display screen of claim 7 , wherein:
each second stripe divider has an optically absorbent side that is opposite to the optically reflective side and absorbs visible ambient light.
9. The display screen as in claim 1 , wherein:
each of the plurality of first filter stripes is a multi-layer structure that forms a band-pass interference filter with a respective transmission band.
10. The display screen as in claim 1 , wherein:
each of the plurality of first filter stripes are made of dye-based or pigment-based colorants.
11. The display screen of 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.
12. The display screen as in claim 1 , wherein:
the entrance layer comprises a prismatic layer which includes a plurality of prism elements.
13. The display screen as in claim 1 , wherein:
the entrance layer comprises a dielectric layer with a flat surface to receive the excitation light.
14. The display screen of claim 1 , wherein:
the entrance layer is a high index dielectric layer.
15. A display screen, comprising:
a plurality of screen layers forming a planar stack, the screen layers including:
a fluorescent layer comprising a plurality of parallel fluorescent stripes, wherein the plurality of parallel fluorescent stripes each absorbs excitation light and emits visible light of a respective color, and wherein adjacent fluorescent stripes emit visible light of different respective colors;
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; and
a first filter layer on a second side of the fluorescent layer opposite to the first side, wherein the first filter layer comprises a plurality of parallel, first filter stripes, each first filter stripe is aligned with a corresponding fluorescent stripe along a direction perpendicular to the screen layers, the first filter stripe transmits visible light of the respective color emitted by the corresponding fluorescent stripe and absorbs visible light of the respective colors emitted by other fluorescent stripes adjacent to the corresponding fluorescent stripe, and wherein each first filter stripe is separated from its corresponding fluorescent stripe by a respective dielectric layer, the respective dielectric layer having a lower refractive index than the fluorescent layer, and
a plurality of parallel stripe dividers, wherein each stripe divider is located between a pair of adjacent fluorescent stripes in the fluorescent layer and between a pair of adjacent filter stripes in the first filter layer.
16. The display screen as in claim 15 , wherein:
the respective dielectric layer is an air-filled gap.
17. The display screen of claim 15 , 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.
18. The display screen as in claim 15 , wherein:
the entrance layer comprises a prismatic layer which includes a plurality of prism elements.
19. The display screen as in claim 15 , wherein:
the entrance layer comprises a dielectric layer with a flat surface to receive the excitation light.
20. The display screen of claim 15 , wherein:
the entrance layer is a high index dielectric layer.
21. A display screen, comprising:
a plurality of screen layers forming a planar stack, the screen layers including:
a fluorescent layer comprising a plurality of parallel fluorescent stripes, wherein the plurality of parallel fluorescent stripes each absorbs excitation light and emits visible light of a respective color, and wherein adjacent fluorescent stripes emit visible light of different respective colors;
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; and
a first filter layer on a second side of the fluorescent layer opposite to the first side, wherein the first filter layer comprises a plurality of parallel, first filter stripes, each first filter stripe is aligned with a corresponding fluorescent stripe along a direction perpendicular to the screen layers, the first filter stripe transmits visible light of the respective color emitted by the corresponding fluorescent stripe and absorbs visible light of the respective colors emitted by other fluorescent stripes adjacent to the corresponding fluorescent stripe; and
a dielectric layer in contact with the fluorescent layer on the second side of the fluorescent layer.
22. The display screen as in claim 21 , wherein:
the fluorescent layer further includes a plurality of first stripe dividers, each first stripe divider located between a respective pair of adjacent fluorescent stripes in the fluorescent layer;
the first filter layer further includes a plurality of second stripe dividers, each second stripe divider located between a respective pair of adjacent filter stripes in the first filter layer; and
the plurality of second stripe dividers are in contact with the dielectric layer and separate the plurality of first filter stripes from the dielectric layer by a gap.
23. The display screen as in claim 22 , wherein:
the gap is filled with a material having a lower refractive index than the dielectric layer.
24. The display screen as in claim 22 , wherein:
the dielectric layer is a dichroic layer that transmits the visible light and reflects the excitation light.
25. The display screen of claim 21 , 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.
26. The display screen as in claim 21 , wherein:
the entrance layer comprises a prismatic layer which includes a plurality of prism elements.
27. The display screen as in claim 21 , wherein:
the entrance layer comprises a dielectric layer with a flat surface to receive the excitation light.
28. The display screen of claim 21 , wherein:
the entrance layer is a high index dielectric layer.