EP0169622A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Anti-veiling-glare glass input window for an optical device and method for manufacturing such window
Assignee: Optische Industrie de Oude Delft NV
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Filing: 1985-07-25
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Granted: —
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Expires: 2005-07-25
Abstract
Abstract Anti-veiling-glare glass input window for an optical device. The window has throughout a shallow surface layer over its peripheral surfaces radiation absorbent free-metal-induced colour centres. A method for preparation of such a window, which is particularly suited to be used as an input window for an image intensifier, involves pre-shaping the window from clear glass and forming colour centres in a shallow surface layer over at least the peripheral surfaces of the window. If the clear glass contains reduceable metal oxides the colour centres are formed by subjecting at least the peripheral surfaces of the clear glass to a reducing atmosphere at a temperature high enough to cause the reducing atmospheres reducing component to diffuse into a shallow surface layer of the window and to reduce the metal oxides to free metal atoms.
Inventors
- 👤 Jonathan Ross Howorth
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 09:39
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; C; C03; C03C; C03C14/00; C03C14/006; C03C23/00; H01J9/00; H01J9/24; C03C2214/00; C03C2214/08
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
48 words
An anti-veiling-glare glass input window for an optical device, in particular suitable to be used as an input window for an image intensifier , characterized in that the window comprises a clear glass faceplate having throughout a shallow surface layer over its peripheral surfaces radiation-absorbent free-metal-induced colour centres.
Claim 2
Dependent Claim
48 words
An anti-veiling-glare glass input window for an optical device, in particular suitable to be used as an input window for an image intensifier , characterized in that the window comprises a clear glass faceplate having throughout a shallow surface layer over its peripheral surfaces radiation-absorbent free-metal-induced colour centres.
Claim 3
Dependent Claim
22 words
A window as claimed in claim 1 characterized in that the clear glass faceplate consists of a glass containing reduceable metal oxides.
Claim 4
Dependent Claim
60 words
A window as claimed in claim 2 characterized in that the glass is a boro-silicate glass containing about 67% Si0 2 , 19% B 2 0 3 , and smaller quantities of A1 2 0 3 and K 2 0 3 together with traces of Na, Li, As, Co and other impurities, specifically lanthanum and zirconium at the parts-per-million level.
Claim 5
Dependent Claim
23 words
A window as claimed in claim 1 characterized in that the shallow surface layer extends to a depth of 0.5 mm or less.
Claim 6
Dependent Claim
84 words
A window as claimed in claim 1 to be used as an input window for an image intensifier, the window in cross-sectional view having the shape of a short and broad T, having an input face and a photocathode receiving face, and having at the input face side a circumferential flange and further having a bevelled circumferential surface extending between the photocathode receiving face and the flange, characterized in that the peripheral surfaces having the shallow surface layer comprise at least the bevelled surface.
Claim 7
Dependent Claim
38 words
A window as claimed in claim 5 characterized in that the peripheral surfaces having the shallow surface layer comprise further the side surface of the flange and the surface of the flange facing away from the input face.
Claim 8
Dependent Claim
84 words
An image intensifier device having a glass input window, the window in cross-sectional view having the shape of a short and broad T, having an input face and a photocathode receiving face, and having at the input face side a circumferential flange and further having a bevelled circumferential surface extending between the photocathode receiving face and the flange, characterized in that the input window made from clear glass having throughout a shallow layer over at least the bevelled surface radiation absorbent free-metal-induced colour centres.
Claim 9
Dependent Claim
84 words
An image intensifier device having a glass input window, the window in cross-sectional view having the shape of a short and broad T, having an input face and a photocathode receiving face, and having at the input face side a circumferential flange and further having a bevelled circumferential surface extending between the photocathode receiving face and the flange, characterized in that the input window made from clear glass having throughout a shallow layer over at least the bevelled surface radiation absorbent free-metal-induced colour centres.
Claim 10
Independent Claim
65 words
A method for the preparation of an anti-veiling-glare glass input window for an optical device, in particular suitable to be used as an input window for an image intensifier characterized by the steps of a) pre-shaping the window from clear glass to its desired form; b) forming radiation absorbent colour centres in a shallow surface layer of at least the peripheral surfaces of the window.
Claim 11
Independent Claim
65 words
A method for the preparation of an anti-veiling-glare glass input window for an optical device, in particular suitable to be used as an input window for an image intensifier characterized by the steps of a) pre-shaping the window from clear glass to its desired form; b) forming radiation absorbent colour centres in a shallow surface layer of at least the peripheral surfaces of the window.
Claim 12
Independent Claim
18 words
A method according to claim'8, characterized in that the colour centres are formed by implantation of metal atoms.
Claim 13
Dependent Claim
76 words
- 10. A method according to claim 8 characterized in that the window is shaped from clear glass containing small quantities of reduceable metal oxides; and that at least the peripheral surfaces of the window are subjected to a reducing atmosphere at a temperature high enough to cause the atmospheres reducing component to diffuse into a shallow surface layer and there reduce at least partly the metal oxides to free metal atoms forming the colour centres.
Claim 14
Dependent Claim
52 words
A method according to claim 10, characterized in that the entire surface of the window is subjected to the reducing atmosphere whereby a radiation absorbent shallow surface layer containing colour centres is formed over this entire surface, and that subsequently this layer is removed from those areas where it is not required.
Claim 15
Dependent Claim
16 words
A method according to claim 10, characterized in that the reducing atmosphere is a hydrogen atmosphere.
Claim 16
Dependent Claim
28 words
A method according to claim 10, characterized in that the diffusion of the reducing component of the reducing atmosphere is effected at a temperature between 600°C and 800°C.
Claim 17
Dependent Claim
25 words
A method according to claim 13, characterized in that the diffusion is effected at a temperature between 620 0 C and 700 9 C .
Claim 18
Dependent Claim
28 words
A method according to claim 10, characterized in that at least the peripheral surfaces of the preshaped window are roughened before subjecting the window to the reducing atmosphere.
Claim 19
Dependent Claim
16 words
A method according to claim 15, characterized in that the roughening is effected by mildly etching.
Claim 20
Dependent Claim
17 words
A method according to claim 16, characterized in that the etching is effected in aqueous hydrofluoric acid.
Claim 21
Dependent Claim
16 words
A method according to claim 16, characterized in that the etching is effected in aqueous NaOH.
Claim 22
Independent Claim
94 words
A method for the preparation of an anti-veiling glare glass input window for an optical device comprising the steps of a) preshaping the window from a clear glass containing quantities of reduceable metal oxides; b) etching the entire surface of the preshaped window; c) subjecting the entire surface of the etched window to a hydrogen atmosphere at a temperature between 620 0 C and 700 0 C, and thereby forming colour centres in a shallow surface layer; d) removing the colour centre containing layer from areas where it is not required by mechanical means.
Claim 23
Independent Claim
94 words
A method for the preparation of an anti-veiling glare glass input window for an optical device comprising the steps of a) preshaping the window from a clear glass containing quantities of reduceable metal oxides; b) etching the entire surface of the preshaped window; c) subjecting the entire surface of the etched window to a hydrogen atmosphere at a temperature between 620 0 C and 700 0 C, and thereby forming colour centres in a shallow surface layer; d) removing the colour centre containing layer from areas where it is not required by mechanical means.
Claim 24
Independent Claim
160 words
A method for the preparation of an anti-veiling glare glass input window for an image intensifier having a gallium containing photocathode bonded to one face of the input window, the method comprising at least the steps of preshaping an input window from clear glass containing quantities of metal oxides; reducing the metal oxides in a shallow surface layer of at least the peripheral surfaces of the window by subjecting at least the peripheral surfaces to a reducing atmosphere to obtain free metal atoms in the shallow surface layer the free metal atoms constituting radiation absorbent colour centres, pressing a preshaped photocathode layer against one of the major surfaces of the window during the reducing step and heating the window during the pressing and reducing step to a temperature between 620°C and 700 0 C to effect during the same step diffusion of the reducing atmospheres reducing agent into the shallow surface layer and bonding of the photocathode to the window.
Claim 25
Independent Claim
160 words
A method for the preparation of an anti-veiling glare glass input window for an image intensifier having a gallium containing photocathode bonded to one face of the input window, the method comprising at least the steps of preshaping an input window from clear glass containing quantities of metal oxides; reducing the metal oxides in a shallow surface layer of at least the peripheral surfaces of the window by subjecting at least the peripheral surfaces to a reducing atmosphere to obtain free metal atoms in the shallow surface layer the free metal atoms constituting radiation absorbent colour centres, pressing a preshaped photocathode layer against one of the major surfaces of the window during the reducing step and heating the window during the pressing and reducing step to a temperature between 620°C and 700 0 C to effect during the same step diffusion of the reducing atmospheres reducing agent into the shallow surface layer and bonding of the photocathode to the window.
References Cited (Backward Citations)
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