EP0350883A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Combination of photosensitive elements for use in radiography
Assignee: 3M Co
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Filing: 1989-07-12
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Granted: —
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Expires: 2009-07-12
Abstract
Abstract Combination of photosensitive elements for use in radiography consisting of a pair of radiographic fluorescent screens and a double-side coated silver halide radiographic element. Each screen is arranged adjacent to each silver halide layer and each screen is capable of imagewise emitting radiation to which the adjacent silver halide layer is sensitive when imagewise exposed to X radiation. The combination is characterized in that one fluorescent screen emits a first radiation in a first wavelength region of the electromagnetic spectrum and the other fluorescent screen emits a second radiation in a second wavelength region of the electromagnetic spectrum, and each silver halide layer is substantially insensitive to the radiation emitted by the opposite screen.
Inventors
- 👤 Sergio Pesce
- 👤 John M. Winslow
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 23:07
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/16; G03C5/17
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
299 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen is in a wavelength region of non-actinic radiation and said second radiation emitted by said back screen is in a wavelength region of actinic radiation, b) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, c) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and d) said back silver halide emulsion layer is sub stantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 2
Dependent Claim
299 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen is in a wavelength region of non-actinic radiation and said second radiation emitted by said back screen is in a wavelength region of actinic radiation, b) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, c) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and d) said back silver halide emulsion layer is sub stantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 3
Dependent Claim
58 words
The combination of claim 1, wherein a) said front screen comprises a non-actinic light emitting phosphor and said front silver halide layer comprises silver halide grains spectrally sensitized to the radiation emitted by said front screen, and b) said back screen comprises a UV emitting phosphor and said back silver halide layer comprises spectrally insensitized silver halide grains.
Claim 4
Dependent Claim
15 words
The combination of claim 1, wherein said front screen comprises a substantially green emitting phosphor.
Claim 5
Dependent Claim
39 words
The combination of claim 1, wherein said front screen comprises a green emitting phosphor having more than 80% of its spectral emission above 480 nm and its maximum of emission in the wavelength range of 530 - 570 nm.
Claim 6
Dependent Claim
125 words
The combination of claim 1, wherein said front screen comprises a green emitting phosphor represented by the general formula (Ln 1-a-b , Tb a , Tm b )₂O₂S wherein Ln is at least one rare earth selected from lanthanium, gadolinium and lutetium, and a and b are numbers such as to meet the conditions of 0.0005 ≦ a ≦ 0.09 and 0 ≦ b ≦ 0.01, respectively, or the general formula (Y 1-c-a-b ,Ln c ,Tb a ,Tm b )₂O₂S wherein Ln is at least one rare earth selected from lanthanium, gadolinium and lutetium, and a, b and c are numbers such as to meet the conditions of 0.0005 ≦ a ≦ 0.09, 0 ≦ b ≦ 0.01 and 0.65 ≦ c ≦ 0.95, respectively.
Claim 7
Dependent Claim
26 words
The combination of claim 1, wherein said front screen comprises a terbium-activated gadolinium or lanthanium oxysulphide phosphor having substantially emission peaks at 487 and 545 nm.
Claim 8
Dependent Claim
27 words
The combination of claim 1, wherein said front silver halide layer comprises silver halide grains spectrally sensitized with spectral sensitizing dyes of the cyanine or merocyanine dyes.
Claim 9
Dependent Claim
38 words
The combination of claim 4, wherein said front silver halide layer comprises silver halide grains spectrally sensitized with sensitizing dyes in such a way that it is sensitive for light in wavelength range of 530 - 570 nm.
Claim 10
Dependent Claim
147 words
The combination of claim 4, wherein said front silver halide emulsion layer comprises silver halide grains spectrally sensitized with sensitizing dyes represented by the general formula wherein R₁₀ represents a hydrogen atom or an alkyl group, R₆, R₇, R₈ and R₉ each represent a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an amino group, an acylamino group, an acyloxy group, an alkoxycarbonyl group, an alkyl group, an alkoxycarbonylamino group or an aryl group, or, together, R₆ and R₇, and respectively R₈ and R₉ can be the atoms necessary to complete a benzene ring, R₁₁ and R₁₂ each represent an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyl group containing alkyl group, a sulfo group containing alkyl group, a benzyl group, a phenethyl group or a vinylmethyl group, X⁻ represents an acid anion and n represents 1 or 2.
Claim 11
Dependent Claim
39 words
The combination of claim 2, wherein said back screen comprises a UV emitting phosphor having more than 80% of its spectral emission below 410 nm and its maximum of emission in the wavelength range of 300 - 360 nm.
Claim 12
Dependent Claim
53 words
The combination of claim 2, wherein said back screen comprises a UV emitting phosphor selected in the class consisting of lead or lanthanum activated barium sulfate phosphors, barium fluorohalide phosphors, lead activated barium silicate phosphors, gadolinium activated yttrium oxide phosphors, barium fluoride phosphors, and alkali metal activated rare earth niobate or tantalate phosphors.
Claim 13
Dependent Claim
52 words
The combination of claim 2, wherein said back screen comprises a UV emitting phosphor corresponding to the general formula (Y 1-2/3x-1/3y , Sr x , Li y ) TaO₄ wherein x and y are numbers such as to meet the conditions 10⁻⁵ ≦ x ≦ 1 and 10⁻⁴ ≦ y ≦ 0.1.
Claim 14
Dependent Claim
19 words
The combination of claim 2, wherein said back silver halide layer comprises chemically sensitized spectrally insensitized silver bromoiodide grains.
Claim 15
Independent Claim
286 words
A method for recording a radiation image comprising the steps of (i) imagewise exposing to X radiations a combination of photosensitive elements comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, and (ii) developing said silver halide radiographic element halide, characterized in that a) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 16
Independent Claim
286 words
A method for recording a radiation image comprising the steps of (i) imagewise exposing to X radiations a combination of photosensitive elements comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, and (ii) developing said silver halide radiographic element halide, characterized in that a) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 17
Dependent Claim
64 words
The method for recording a radiation image according to claim 14, wherein a) said front screen comprises a non-actinic radiation emitting phosphor and said front silver halide layer comprises silver halide grains spectrally sensitized to the radiation emitted by said front screen, and b) said back screen comprises a UV emitting phosphor and said back silver halide layer comprises spectrally insensitized silver halide grains.
Claim 18
Dependent Claim
45 words
The method for recording a radiation image according to claim 14, wherein said front screen comprises a green emitting phosphor having more than 80% of its spectral emission above 480 nm and its maximum of emission in the wavelength range of 530 - 570 nm.
Claim 19
Dependent Claim
132 words
The method for recording a radiation image according to claim 14, wherein said front screen comprises a green emitting phosphor represented by the general formula (Ln 1-a-b , Tb a , Tm b )₂O₂S wherein Ln is at least one rare earth selected from lanthanium, gadolinium and lutetium, and a and b are numbers such as to meet the conditions of 0.0005 ≦ a ≦ 0.09 and 0 ≦ b ≦ 0.01, respectively, or the general formula (Y 1-c-a-b ,Ln c ,Tb a , Tm b )₂O₂Tb wherein Ln is at least one rare earth selected from lanthanium, gadolinium and lutetium, and a, b and c are numbers such as to meet the conditions of 0.0005 ≦ a ≦ 0.09, 0 ≦ b ≦ 0.01 and 0.65 ≦ c ≦ 0.95, respectively.
Claim 20
Dependent Claim
32 words
The method for recording a radiation image according to claim 14, wherein said front screen comprises a terbium-activated gadolinium or lanthanium oxysulphide phosphor having substantially emission peaks at 487 and 545 nm.
Claim 21
Dependent Claim
33 words
The method for recording a radiation image according to claim 14, wherein said front silver halide layer comprises silver halide grains spectrally sensitized with spectral sensitizing dyes of the cyanine or merocyanine dyes.
Claim 22
Dependent Claim
44 words
The method for recording a radiation image according to claim 14, wherein said front silver halide layer comprises silver halide grains spectrally sensitized with sensitizing dyes in such a way that it is sensitive for light in wavelength range of 530 - 570 nm.
Claim 23
Dependent Claim
153 words
The method for recording a radiation image according to claim 14, wherein said front silver halide emulsion layer comprises silver halide grains spectrally sensitized with sensitizing dyes represented by the general formula wherein R₁₀ represents a hydrogen atom or an alkyl group, R₆, R₇, R₈ and R₉ each represent a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an amino group, an acylamino group, an acyloxy group, an alkoxycarbonyl group, an alkyl group, an alkoxycarbonylamino group or an aryl group, or, together, R₆ and R₇, and respectively R₈ and R₉ can be the atoms necessary to complete a benzene ring, R₁₁ and R₁₂ each represent an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyl group containing alkyl group, a sulfo group containing alkyl group, a benzyl group, a phenethyl group or a vinylmethyl group, X⁻ represents an acid anion and n represents 1 or 2.
Claim 24
Dependent Claim
45 words
The method for recording a radiation image according to claim 14, wherein said back screen comprises a UV emitting phosphor having more than 80% of its spectral emission below 410 nm and its maximum of emission in the wavelength range of 300 - 360 nm.
Claim 25
Dependent Claim
59 words
The method for recording a radiation image according to claim 14, wherein said back screen comprises a UV emitting phosphor selected in the class consisting of lead or lanthanum activated barium sulfate phosphors, barium fluorohalide phosphors, lead activated barium silicate phosphors, gadolinium activated yttrium oxide phosphors, barium fluoride phosphors, and alkali metal activated rare earth niobate or tantalate phosphors.
Claim 26
Dependent Claim
57 words
The method for recording a radiation image according to claim 14, wherein said back screen comprises a UV emitting phosphor corresponding to the general formula (Y 1-2/3x-1/3y , Sr y, Li z ) TaO₄ wherein x and y are numbers such as to meet the conditions 10⁻⁵ ≦ x ≦ 1 and 10⁻⁴ ≦ y ≦ 0.1.
Claim 27
Dependent Claim
25 words
The method for recording a radiation image according to claim 14, wherein said back silver halide layer comprises chemically sensitized spectrally insensitized silver bromoiodide grains.
Claim 28
Dependent Claim
62 words
A silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, characterized in that said front silver halide emulsion layer comprises silver halide grains sensitive to a wavelength region of the non-actinic radiation, and said back silver halide emulsion layer comprises UV or blue sensitive silver halide grains.
Claim 29
Dependent Claim
62 words
A silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, characterized in that said front silver halide emulsion layer comprises silver halide grains sensitive to a wavelength region of the non-actinic radiation, and said back silver halide emulsion layer comprises UV or blue sensitive silver halide grains.
Claim 30
Dependent Claim
264 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 31
Dependent Claim
264 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen has a wavelength which differs from said second radiation emitted by said back screen by at least 50 nm, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen, the difference in wavelength region of said first and second radiations and the insensitivity of each silver halide layer to radiation emitted by opposite screen being such to reduce crossover exposure of at least 10 percent when compared with a symmetrical combination of a pair of green light emitting fluorescent screens and a double coated green sensitized silver halide radiographic element.
Claim 32
Dependent Claim
213 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen is in a first wavelength region of the electromagnetic spectrum and said second radiation emitted by said back screen is in a second wavelength region of the electromagnetic spectrum, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen.
Claim 33
Dependent Claim
213 words
A combination of photosensitive elements for use in radiography comprising two separate front and back X-ray fluorescent screens and a silver halide radiographic element comprising a support base and front and back silver halide emulsion layers each coated on one surface of said support, wherein said front screen is arranged adjacent to said front silver halide layer and said back screen is arranged adjacent to said back silver halide layer, and wherein 1) said front screen comprises a first radiation emitting phosphor and said front silver halide layer comprises silver halide grains sensitive to said first radiation emitted by said front screen, and 2) said back screen comprises a second radiation emitting phosphor and said back silver halide layer comprises silver halide grains sensitive to said second radiation emitted by said back screen, characterized in that a) said first radiation emitted by said front screen is in a first wavelength region of the electromagnetic spectrum and said second radiation emitted by said back screen is in a second wavelength region of the electromagnetic spectrum, b) said front silver halide emulsion layer is substantially insensitive to said second radiation emitted by said back screen, and c) said back silver halide emulsion layer is substantially insensitive to said first radiation emitted by said front screen.
References Cited (Backward Citations)
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