Scanning beam displays based on light-emitting screens having phosphors
View Patent ↗This specification describes phosphor compositions used in fluorescent layers for scanning beam displays. In general, one aspect of the subject matter described in this specification can be embodied in a display device having a fluorescent layer that absorbs an excitation light at a single wavelength and emits visible light. The fluorescent layer includes a plurality of parallel fluorescent stripes. At least three adjacent fluorescent stripes are made of three different fluorescent materials, which include a first fluorescent material that absorbs the excitation light and emits light of a first color, a second fluorescent material that absorbs the excitation light and emits light of a second color, and a third fluorescent material that absorbs the excitation light and emits light of a third color.
1. A display device, comprising a display screen that includes a fluorescent layer that absorbs an excitation light at a single excitation wavelength and emits visible light, the fluorescent layer comprising:
a plurality of parallel fluorescent stripes elongated along a first direction and spaced from one another along a second direction perpendicular to the first direction, wherein at least three adjacent fluorescent stripes are made of three different fluorescent materials: a first fluorescent material that absorbs the excitation light and emits light of a first color, a second fluorescent material that absorbs the excitation light and emits light of a second color, and a third fluorescent material that absorbs the excitation light and emits light of a third color;
a plurality of diode lasers that respond to respective laser current control signals to produce modulated laser excitation beams of the excitation light at the single excitation wavelength, one modulated laser excitation beam from each diode laser per one laser current control signal carrying images of different colors in the respective laser current control signal;
a controller that generates the laser current control signals that respectively carry images and are applied to the diode lasers;
a beam scanning mechanism that receives the modulated laser beams at the single excitation wavelength and scans, simultaneously and along the second direction, the modulated laser excitation beams on to the display screen at different and adjacent screen positions along the first direction in one screen segment of the display screen, to produce different scan lines along the second direction, respectively, in the screen segment, to cause fluorescent layer of the display screen to emit light of the first, second and third colors at different times at different positions in each scan line along the second direction produced by each modulated laser excitation beam and, to shift, simultaneously, the modulated laser excitation beams to other screen segments at different positions in the display screen along the first direction, one screen segment at a time, to render the images; and
a relay optics module placed in optical paths of the modulated laser beams between the diode lasers and the beam scanning mechanism to modify and direct the modulated laser beams in a way to be scanned along the first and second directions onto the display screen by the beam scanning mechanism,
wherein one of the different fluorescent materials in the fluorescent stripes includes an Oxide-based phosphor, a Silicate-based phosphor, a Phosphate-based phosphor, a Borate-based phosphor, an Aluminate-based phosphor, a Gallate-based phosphor, a Molybdate-based phosphor, a Tungstate-based phosphor, a Fluoride-based phosphor, a Sulfide-based phosphor, and a Sulfoselenide-based phosphor.
2. A display device, comprising a display screen that includes a fluorescent layer that absorbs an excitation light at a single excitation wavelength and emits visible light, the fluorescent layer comprising:
a plurality of parallel fluorescent stripes elongated along a first direction and spaced from one another along a second direction perpendicular to the first direction, wherein at least three adjacent fluorescent stripes are made of three different fluorescent materials: a first fluorescent material that absorbs the excitation light and emits light of a first color, a second fluorescent material that absorbs the excitation light and emits light of a second color, and a third fluorescent material that absorbs the excitation light and emits light of a third color;
a plurality of diode lasers that respond to respective laser current control signals to produce modulated laser excitation beams of the excitation light at the single excitation wavelength, one modulated laser excitation beam from each diode laser per one laser current control signal carrying images of different colors in the respective laser current control signal;
a controller that generates the laser current control signals that respectively carry images and are applied to the diode lasers; and
a beam scanning mechanism that receives the modulated laser beams at the single excitation wavelength and scans, simultaneously and along the second direction, the modulated laser excitation beams on to the display screen at different and adjacent screen positions along the first direction in one screen segment of the display screen, to produce different scan lines along the second direction, respectively, in the screen segment, to cause fluorescent layer of the display screen to emit light of the first, second and third colors at different times at different positions in each scan line along the second direction produced by each modulated laser excitation beam and, to shift, simultaneously, the modulated laser excitation beams to other screen segments at different positions in the display screen along the first direction, one screen segment at a time, to render the images,
wherein one of the different fluorescent materials in the fluorescent stripes includes an Oxide-based phosphor, a Silicate-based phosphor, a Phosphate-based phosphor, a Borate-based phosphor, an Aluminate-based phosphor, a Gallate-based phosphor, a Molybdate-based phosphor, a Tungstate-based phosphor, a Fluoride-based phosphor, a Sulfide-based phosphor, and a Sulfoselenide-based phosphor,
wherein the Silicate-based phosphor comprises at least one of (Mg, Ba, Sr, Ca, Zn) 2 SiO 4 :(Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr); (Mg, Ba, Sr, Ca)SiO 4 :Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr; (Mg, Ba, Sr, Ca)SiO 5 :Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr; ZrSiO 4 :Pr; Ca 3 Sc 2 Si 3 O 12 :Ce; Y 2 SiO 5 :Tb; Y 2 Si 2 O 7 :Tb; CaMgSiO:Ce; Ca 2 MgSi 2 O 7 :Ce; (Ca, Sr) 2 Al 2 SiO 7 :Ce; SrAl 2 Si 2 O 8 :Eu; CaMgSi 2 O 6 :Eu; SrAl 10 SiO 20 :Eu; Sr 3 MgSi 2 O 8 :Eu; Sr 1. . . 3 Mg 0.7 SiO 4 :Eu; (Ba, Sr, Ca) 3 MgSi 2 O 8 :Eu; Y 2 SiO 5 :Ce; Sr 2 Si 3 O 8 .2SrCl 2 :Eu; BaSi 2 O 5 :Eu; and Sr 3 MgSi 2 O 7 :Eu.
3. The device as in claim 1 , wherein the Phosphate-based phosphor comprises at least one of Zn 2 (PO 4 ) 2 :Mn; (Mg, Ba, Ca, Sr) 5 (PO 4 ) 3 Cl:(Eu, Sm, Ce); and (Sr, Ca, Eu) 10 (PO 4 ) 6 Cl 2 .0.24B 2 O 3 .
4. The device as in claim 1 , wherein the Borate-based phosphor comprises at least one of (Y, Gd, La, Lu)BO 3 :Eu, Sm, Ce, Bi; Y(Mg, Ba, Ca, Sr) 3 (Al, Ga, In) 3 B 4 O 15 :Eu; and YCa 3 Ga 3 B 4 O 15 :Eu.
5. The device as in claim 1 , wherein the Aluminate-based phosphor comprises at least one of (Y, Gd)Al 5 O 12 :(Eu, Ce, Pr); (Mg, Ba, Ca, Sr)MgAl 10 O 17 :(Eu, Mn); (Ca, Mg, Ba, Zn)Al 2 O 4 :(Mn, Eu, Dy); (Ba, Mg, Ca, Sr)MgAl 14 O 23 :Mn, Eu; (Mg, Ba, Ca, Sr)Al 12 O 19 :Mn; and BaMg 2 Al 16 O 27 :Eu, Mn.
6. The device as in claim 1 , wherein the Gallate-based phosphor comprises at least one of (Y, Gd) 3 Ga 5 O 12 :(Eu, Ce, Pr); (Ca, Mg, Ba, Zn)Ga 2 O 4 :(Mn, Eu, Dy); ZnGa 2 O 4 :Mn; and (Li 0.5 Ga 0.5 ) 0.5 Zn 0.5 Ga 2 O 4 .
7. The device as in claim 1 , wherein the Molybdate-based phosphor comprises at least one of (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X Mo 2 O 8 and(Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X Mo 2 O 8 :Sm.
8. The device as in claim 1 , wherein the Tungstate-based phosphor comprises at least one of (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X W 2 O 8 ;(Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X W 2 O 8 :Sm; and CaWO 4 :Tb, Pb.
9. The device as in claim 1 , wherein the Fluoride-based phosphor comprises at least one of (KF, MgF 2 ):Mn, MgF 2 :Mn, (Zn, Mg)F 2 :Mn; 3.5MgO.0.5MgF 2 .GeO 2 :Mn; and Mg 4 (F)(Ge, Sn)O 6 :Mn.
10. The device as in claim 1 , wherein the Sulfide-based phosphor comprises at least one of (Be, Mg, Ca, Sr, Ba, Zn)S:(Eu, Ce, Cu, Ag, Al, Au, Tb, Cl, Pr, Mn, Bi); (Be, Mg, Ca, Sr, Ba, Zn)(Al, Ga, In, Y, La, Gd) 2 S 4 :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn); (Mg, Ca, Sr, Ba) 2 (Zn, Si, Ge, Sn)S 3 :Eu; and (Mg, Ca, Sr, Ba) 2 (Al, Ga, In, Y, La, Ga) 2 S 3 :Eu.
11. The device as in claim 1 , wherein the Sulfoselenide-based phosphor comprises at least one of (Be, Mg, Ca, Sr, Ba, Zn)Se X S 1-X :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn) and (Be, Mg, Ca, Sr, Ba, Zn)(Al, Ga, In, Y, La, Gd) 2 (Se X S 1-X ) 4 :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn).
12. A display device, comprising:
a display screen having a fluorescent layer formed of fluorescent regions that absorb excitation light at an excitation wavelength and emit visible light, two adjacent fluorescent regions formed of different materials that emit visible light of different colors;
an array of lasers that respectively produce excitation laser beams of the excitation light at the excitation wavelength, each excitation laser beam modulated to carry time-domain coded image information for a colored image to be displayed on the display screen; and
a beam scanning mechanism that receives the excitation laser beams and simultaneously scans the excitation laser beams onto the display screen at different display screen positions in a first direction to scan the excitation laser beams in a second direction to cause emission of visible light of different colors in different fluorescent regions at different times and different positions along each scan line in the second direction to produce the colored image on the display screen,
wherein the display screen further includes a contrast enhancement layer positioned to filter the visible light emitted by the fluorescent layer for forming images displayed by the display screen to one or more viewers, the contrast enhancement layer including different filtering regions that spatially align with and match respective fluorescent regions in the fluorescent layer and each filtering region transmitting light of a color that is emitted by a corresponding matching fluorescent region and blocking light of other colors,
wherein a fluorescent region of the display screen includes:
a Silicate-based phosphor which includes (Mg, Ba, Sr, Ca, Zn) 2 SiO 4 :(Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr); (Mg, Ba, Sr, Ca)SiO 4 :Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr; (Mg, Ba, Sr, Ca)SiO 5 :Eu, Ce, Mn, Ti, Pb, Sn, Li, Pr; ZrSiO 4 :Pr; Ca 3 Sc 2 Si 3 O 12 :Ce; Y 2 SiO 5 :Tb; Y 2 Si 2 O 7 :Tb; CaMgSiO:Ce; Ca 2 MgSi 2 O 7 :Ce; (Ca, Sr) 2 Al 2 SiO 7 :Ce; SrAl 2 Si 2 O 8 :Eu; CaMgSi 2 O 6 :Eu; SrAl 10 SiO 20 :Eu; Sr 3 MgSi 2 O 8 :Eu; Sr 1 . . .3 Mg 0.7 SiO 4 :Eu; (Ba, Sr, Ca) 3 MgSi 2 O 8 :Eu; Y 2 SiO 5 :Ce; Sr 2 Si 3 O 8 .2SrCl 2 :Eu; BaSi 2 O 5 :Eu; or Sr 3 MgSi 2 O 7 :Eu; or
a Phosphate-based phosphor which includes Zn 2 (PO 4 ) 2 :Mn; (Mg, Ba, Ca, Sr) 5 (PO 4 ) 3 Cl:(Eu, Sm, Ce); or (Sr, Ca, Eu) 10 (PO 4 ) 6 Cl 2 .0.24B 2 O 3 ; or
a Borate-based phosphor which includes (Y, Gd, La, Lu)BO 3 :Eu, Sm, Ce, Bi; Y(Mg, Ba, Ca, Sr) 3 (Al, Ga, In) 3 B 4 O 15 :Eu; or YCa 3 Ga 3 B 4 O 15 :Eu; or
an Aluminate-based phosphor which includes (Y, Gd) 3 Al 5 O 12 :(Eu, Ce, Pr); (Mg, Ba, Ca, Sr)MgAl 10 O 17 :(Eu, Mn); (Ca, Mg, Ba, Zn)Al 2 O 4 :(Mn, Eu, Dy); (Ba, Mg, Ca, Sr)MgAl 14 O 23 :Mn, Eu; (Mg, Ba, Ca, Sr)Al 12 O 19 :Mn; or BaMg 2 Al 16 O 27 :Eu, Mn; or
a Gallate-based phosphor which includes (Y, Gd) 3 Ga 5 O 12 :(Eu, Ce, Pr); (Ca, Mg, Ba, Zn)Ga 2 O 4 :(Mn, Eu, Dy); ZnGa 2 O 4 :Mn; or (Li 0.5 Ga 0.5 ) 0.5 Zn 0.5 Ga 2 O 4 ,; or
a Molybdate-based phosphor comprises at least one of (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X Mo 2 O 8 or (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X Mo 2 O 8 :Sm; or
a Tungstate-based phosphor which includes (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X W 2 O 8 ; (Li, K, Na, Ag)Eu (1-X) (Y, La, Gd) X W 2 O 8 :Sm; or CaWO 4 :Tb, Pb; or
a Fluoride-based phosphor which includes (KF, MgF 2 ):Mn, MgF 2 :Mn, (Zn, Mg)F 2 :Mn; 3.5MgO.0.5MgF 2 .GeO 2 ; or Mg 4 (F) (Ge, Sn) O 6 :Mn, or
a Sulfide-based phosphor which includes (Be, Mg, Ca, Sr, Ba, Zn)S:(Eu, Ce, Cu, Ag, Al, Au, Tb, Cl, Pr, Mn, Bi); (Be, Mg, Ca, Sr, Ba, Zn)(Al, Ga, In, Y, La, Gd) 2 S 4 :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn); (Mg, Ca, Sr, Ba) 2 (Zn, Si, Ge, Sn)S 3 :Eu; or (Mg, Ca, Sr, Ba) 2 (Al, Ga, In, Y, La, Ga) 2 S 3 :Eu; or
a Sulfoselenide-based phosphor which includes (Be, Mg, Ca, Sr, Ba, Zn)Se X S 1-X :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn) or (Be, Mg, Ca, Sr, Ba, Zn)(Al, Ga, In, Y, La, Gd) 2 (Se X S 1-X ) 4 :(Eu, Ce, Cu, Ag, Al, Tb, Cl, Pr, Mn).
13. The display device as in claim 12 , wherein:
the different fluorescent regions of the display screen emit visible light of red, green and blue colors, and
each excitation laser beam carries time-domain coded image information for the red, green and blue colors for each color pixel formed by three adjacent fluorescent regions at different horizontal positions.
14. The device as in claim 12 , wherein:
a fluorescent region of the display screen comprises a non-phosphor organic material.
15. The device as in claim 14 , wherein:
the organic material includes Brilliantsulfoflavine FF, Basic yellow HG, Eosine, Rhodamine 6G, or Rhodamine B.
16. The device as in claim 1 , wherein:
the relay optics module is configured to modify spatial property of the modulated laser beams from the diode lasers to produce a closely packed bundle of modulated laser beams for scanning by the beam scanning mechanism.
17. The device as in claim 1 , further comprising:
a scan lens placed between the beam scanning mechanism and the display screen to project the scanned and modulated laser beams on to the display screen.