http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-729867-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_dac958a206fc8af4cd8bb0de4d01dd1c |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H01J29-385 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G21K4-00 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G21K4-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01J29-38 |
| filingDate | 1953-07-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1955-05-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-729867-A |
| titleOfInvention | Improvements in or relating to fluorescent screens and methods of forming such screens |
| abstract | 729,867. Luminescent screens. WESTING- HOUSE ELECTRIC INTERNATIONAL CO. July 3, 1953 [July 23, 1952], No. 18453/53. Drawings to Specification. Class 39 (1). [Also in Group XXIII] A method of forming a fluorescent screen preferably for an X-ray image intensifier where the screen is closely adjacent a caesiated antimony surface, comprises firstly subjecting a glass surface to the action of a 6 to 8 per cent hydrofluoric acid solution at a temperature of between 30‹ C. and 40 ‹ C. for up to five minutes, secondly subjecting the treated surface to the action of dilute hydrochloric acid followed by distilled water, and then settling phosphor particles on the glass surface from a liquid suspension. The glass may have a composition of SiO 2 80 per cent, Na 2 O 4 per cent, Al 2 O 3 2 per cent and B 2 O 5 14 per cent. The action of the first step is to remove from the glass surface the more soluble oxides leaving a skeleton structure of SiO 2 and of the second step to remove the soluble fluorides. The phosphor, may comprise powdered calcium tungstate, zinc sulphide or zinc-cadmium sulphide; the vehicle may be dilute potassium silicate. The phosphor particles may have a diameter of 1 to 2 microns or for some purposes an average of 20 microns. The glass surface is placed in the settling bath at such time as particles of desired size begin to settle. After removal from the bath the phosphor-coated glass plate is baked to a temperature of about 425 ‹ C. A protective transparent film such as germanium oxide, zinc sulphide, lithium fluoride or calcium fluoride is then applied to the phosphor surface, for example by sublimation. The applied film may contain about 1.0 per cent or less of silver to render it slightly electrically conductive, or it may be coated with a film of tin oxide by spraying a thin oxide solution on it while hot, or a thin layer of silver, chromium, or manganese may be evaporated on. |
| priorityDate | 1952-07-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 40.