IP Library Granted Patent US 9,739,896
Granted Patent B2
US 9,739,896 · App. 15/354,140 · Granted Aug 22, 2017

Coatings for digital detectors

Inventors: Seshadri Jagannathan (Rochester, NY); Timothy J. Tredwell (Fairport, NY); Charles M. Rankin (Penfield, NY); David Gruszczynski (Webster, NY); Daniel M. Leusch (Penfield, NY)
Assignee: Carestream Health, Inc.
G01T1/2012B05D3/12G01T1/161G01T1/20G01T1/2006
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Quick Facts
Patent No.
US 9,739,896
App. No.
15/354,140
Granted
Aug 22, 2017
Kind
B2
Abstract

Described is a scintillator screen that includes a supporting layer having a phosphor dispersed in a polymeric binder disposed on the supporting layer and a barrier layer disposed on the polymeric binder. The barrier layer includes a non-moisture absorbing polymer selected from the group consisting of polyethylene terephthalate, cellulose diacetate, ethylene vinyl acetate and polyvinyl butyraldehyde. The barrier layer has a thickness of less than 1 micron. An antistatic layer is disposed on the barrier layer. The antistatic layer includes poly(3,4-ethylenedixythiophene)-poly(styrene sulfonate) (PEDOT/PSS) dispersed in a polymer selected from the group consisting of a polyester and a polyurethane. The antistatic layer has a transparency of greater than 95 percent at a wavelength of from about 400 nm to 600 nm.

Claims (45)

1. A scintillator screen comprising:

a support layer;

a scintillator layer directly disposed on the support layer, the scintillator layer comprised of a phosphor dispersed in a polymeric binder;

a barrier layer disposed on the scintillator layer, the barrier layer comprising a non-moisture absorbing polymer selected from the group consisting of polyethylene terephthalate, cellulose diacetate, ethylene vinyl acetate and polyvinyl butyraldehyde, wherein the barrier layer has a thickness of less than 1 micron; and

an antistatic layer having an inner surface and an outer surface, the inner surface of the antistatic layer being disposed on the barrier layer, the antistatic layer comprising a poly(3,4-ethylenedixythiophene)-poly(styrene sulfonate) dispersed in a polymer selected from the group consisting of a polyester and a polyurethane;

wherein a transparency of the combination antistatic and barrier layers together is greater than 95 percent at a wavelength of from about 400 nm to 600 nm; and

wherein a surface resistivity of the scintillator screen at the outer surface of the antistatic layer is less than 10 10 ohms/square.

2. The screen of claim 1 , wherein the barrier layer has a transparency of greater than 94 percent at a wavelength of from about 400 nm to 600 nm.

3. The screen of claim 1 , wherein the antistatic layer has a transparency of greater than 94 percent at a wavelength of from about 400 nm to 600 nm.

4. The screen of claim 1 , wherein the phosphor is selected from the group consisting of Gd 2 O 2 S:Tb, Gd 2 O 2 S:Eu, Gd 2 O 3 :Eu, La 2 O 2 S:Tb, La 2 O 2 S, Y 2 O 2 S:Tb, CsI:Tl, CsI:Na, CsBr:Tl, CaWO 4 , CaWO 4 :Tb, BaFBr:Eu, BaFCl:Eu, BaSO 4 :Eu, BaSrSO 4 , BaPbSO 4 , BaAl 12 O 19 :Mn, BaMgAl 10 O 17 :Eu, Zn 2 SiO 4 :Mn, (Zn,Cd)S:Ag, LaOBr, LaOBr:Tm, Lu 2 O 2 S:Eu, Lu 2 O 2 S:Tb, LuTaO 4 , HfO 2 :Ti, HfGeO 4 :Ti, YTaO 4 , YTaO 4 :Gd, YTaO 4 :Nb, Y 2 O 3 :Eu, YBO 3 :Eu, YBO 3 :Tb, and (Y,Gd)BO 3 :Eu.

5. The screen of claim 1 , wherein the polymeric binder is selected from the group consisting of: sodium o-sulfobenzaldehyde acetal of poly(vinyl alcohol); chloro-sulfonated poly(ethylene); bisphenol poly(carbonates);

copolymers of bisphenol carbonates and poly(alkylene oxides); aqueous ethanol soluble nylons; poly(alkyl acrylates and methacrylates): copolymers of poly(alkyl acrylates and methacrylates); poly(vinyl butyral) and poly(urethane) elastomers.

6. The screen of claim 1 , wherein the phosphor comprises particles having a size of from about 0.5 μm to about 40 μm, wherein a phosphor to polymeric binder ratio is from about 7:1 to about 35:1.

7. The screen of claim 1 , wherein the antistatic layer has thickness of from about 0.1 μm to about 0.3 μm.

8. A digital radiography panel comprising:

a scintillator screen comprising:

(a) a support layer;

(b) a phosphor layer comprised of a scintillator dispersed in a polymeric binder, and directly disposed on the support layer;

(c) a non-phosphor layer having a transparency of greater than 95 percent at a wavelength of from about 400 nm to 600 nm, and comprised of:

(i) a barrier layer disposed on the phosphor layer comprising a non-moisture absorbing polymer selected from the group consisting of polyethylene terephthalate, cellulose diacetate, ethylene vinyl acetate and polyvinyl butyraldehyde; and

(ii) an antistatic layer having an inner surface and an outer surface, the inner surface of the antistatic layer being disposed on the barrier layer, the antistatic layer comprising a poly(3,4-ethylenedixythiophene)-poly(styrene sulfonate) dispersed in a polymer selected from the group consisting of a polyester and a polyurethane, wherein a surface resistivity of the scintillator screen at the outer surface of the antistatic layer is less than 10 10 ohms/square; and

a flat panel detector disposed on the outer surface of the antistatic layer.

9. The panel of claim 8 , wherein the barrier layer has a transparency of greater than 95 percent at a wavelength of from about 400 nm to 600 nm.

10. The panel of claim 8 , wherein the antistatic layer has a transparency of greater than 94 percent at a wavelength of from about 400 nm to 600 nm.

11. The panel of claim 8 , wherein the antistatic layer has a surface resistivity less than 10 5 ohms/square.

12. The panel of claim 8 , wherein the phosphor is selected from the group consisting of Gd 2 O 2 S:Tb, Gd 2 O 2 S:Eu, Gd 2 O 3 :Eu, La 2 O 2 S:Tb, La 2 O 2 S, Y 2 O 2 S:Tb, CsI:Tl, CsI:Na, CsBr:Tl, NaI:Tl, CaWO 4 , CaWO 4 :Tb, BaFBr:Eu, BaFCl:Eu, BaSO 4 :Eu, BaSrSO 4 , BaPbSO 4 , BaAl 12 O 19 :Mn, BaMgAl 10 O 17 :Eu, Zn 2 SiO 4 :Mn, (Zn,Cd)S:Ag, LaOBr, LaOBr:Tm, Lu 2 O 2 S:Eu, Lu 2 O 2 S:Tb, LuTaO 4 , HfO 2 :Ti, HfGeO 4 :Ti, YTaO 4 , YTaO 4 :Gd, YTaO 4 :Nb, Y 2 O 3 :Eu, YBO 3 :Eu, YBO 3 :Tb, and (Y,Gd)BO 3 :Eu, and wherein the polymeric binder is selected from the group consisting of: sodium o-sulfobenzaldehyde acetal of poly(vinyl alcohol);

chloro-sulfonated poly(ethylene); bisphenol poly(carbonates); copolymers of bisphenol carbonates and poly(alkylene oxides); aqueous ethanol soluble nylons;

poly(alkyl acrylates and methacrylates): copolymers of poly(alkyl acrylates and methacrylates); poly(vinyl butyral) and poly(urethane) elastomers.

13. The panel of claim 8 , further comprising an adhesive layer disposed between the antistatic layer and the flat panel detector.

14. The panel of claim 8 , wherein:

the barrier layer has a thickness of less than 1 micron;

the scintillator comprises particles having a size of from about 0.5 μm to about 40 μm; and

the antistatic layer has thickness of from about 0.1 μm to about 0.3 μm.

15. A scintillator screen comprising:

a support layer;

a phosphor layer comprised of a phosphor dispersed in a polymeric binder, and directly disposed on the support layer,

a barrier layer disposed on the phosphor layer and comprising a non-moisture absorbing polymer; and

an antistatic layer having an inner surface and an outer surface, the inner surface of the antistatic layer being disposed on the barrier layer, the antistatic layer comprising a poly(3,4-ethylenedixythiophene)-poly(styrene sulfonate) dispersed in a polymer selected from the group consisting of a polyester and a polyurethane;

wherein the antistatic layer and the barrier layer together have a combined transparency of greater than 95 percent at a wavelength of from about 400 nm to 600 nm; and

wherein a surface resistivity of the scintillator screen at the outer surface of the antistatic layer is less than 10 10 ohms/square.

16. The screen of claim 15 , wherein:

the barrier layer has a thickness of less than 1 micron;

the phosphor layer comprises particles having a size of from about 0.5 μm to about 40 μm;

a phosphor to polymeric binder ratio is from about 7:1 to about 35:1; and

the antistatic layer has thickness of from about 0.1 μm to about 0.3 μm.

Assignments (4)
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY (FIRST LIEN) Recorded Oct 14, 2022
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: CARESTREAM HEALTH, INC.; CARESTREAM HEALTH HOLDINGS, INC.; CARESTREAM HEALTH CANADA HOLDINGS, INC.; CARESTREAM HEALTH ACQUISITION, LLC; CARESTREAM HEALTH WORLD HOLDINGS LLC
Reel/Frame 061683/0529 →
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY (SECOND LIEN) Recorded Oct 14, 2022
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: CARESTREAM HEALTH, INC.; CARESTREAM HEALTH HOLDINGS, INC.; CARESTREAM HEALTH CANADA HOLDINGS, INC.; CARESTREAM HEALTH ACQUISITION, LLC; CARESTREAM HEALTH WORLD HOLDINGS LLC
Reel/Frame 061683/0681 →
SECURITY INTEREST Recorded Jan 15, 2019
From: CARESTREAM HEALTH, INC.; CARESTREAM HEALTH HOLDINGS, INC.; CARESTREAM HEALTH CANADA HOLDINGS, INC.; CARESTREAM HEALTH ACQUISITION, LLC; CARESTREAM HEALTH WORLD HOLDINGS LLC
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
Reel/Frame 048077/0529 →
SECURITY INTEREST Recorded Jan 15, 2019
From: CARESTREAM HEALTH, INC.; CARESTREAM HEALTH HOLDINGS, INC.; CARESTREAM HEALTH CANADA HOLDINGS, INC.; CARESTREAM HEALTH ACQUISITION, LLC; CARESTREAM HEALTH WORLD HOLDINGS LLC
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
Reel/Frame 048077/0587 →
Continuity (3)
Continuation 13775639 · Feb 25, 2013
Provisional Application 61603980 · Feb 28, 2012
Related Publication 20170068002A1 · Mar 9, 2017