Method for producing a fluorescent material layer

• US 20040131767A1
• Filed: 11/04/2003
• Published: 07/08/2004
• Est. Priority Date: 08/24/2001
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Schmitt, Bernhard, Hell, Erich, Fuchs, Manfred, Mattern, Detlef
• Application Number:
  US10/476,679
• Publication Number:
  US 20040131767A1
• Time in Patent Office: Days
• US Class Current: 427/8
• CPC Class Codes: C09K 11/7733 with alkali or alkaline earth metals
• CPC Class Codes: C23C 14/0694 Halides
• CPC Class Codes: C23C 14/58 After-treatment
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50

Abstract

The invention relates to a method for producing a fluorescent material layer, comprising the following steps: a)depositing the fluorescent material layer (4) from the vapour phase on a substrate (3), b) measuring the light yield by local resolution and c) annealing the fluorescent material layer (4) by local resolution at points where the light yield is smaller that a predefined value.

Claims

1. Method to produce a luminophore layer (4) with the following steps:

a) deposition of the luminophore layer (4) from the vaporization phase on a substrate (3),

b) locally resolved measurement of the light efficiency and

c) locally resolved tempering of the luminophore layer (4) at locations at which the light efficiency is less than a predetermined value.

2. Method according to claim 1, whereby the steps lit. b and lit. c are repeated until the light efficiency of the luminophore layer (4) at all locations is at most 10%, preferably at most 5%, less than the predetermined value.

3. Method according to claim 1 or 2, whereby the predetermined value is a maximum value measured in the step lit. b.

4. Method according to any of the preceding claims, whereby in each repetition a first temperature of the locally resolved tempering is selected higher than in the preceding locally resolved tempering.

5. Method according to any of the preceding claims, whereby the first temperature in each repetition of the locally resolved tempering is selected 20 to 50°

C. higher.

6. Method according to any of the preceding claims, whereby the entire luminophore layer (4) is tempered at a second temperature in the range of 150 to 250°

C. before the step lit. b.

7. Method according to any of the preceding claims, whereby the first temperature in step lit. c is selected higher than the second temperature.

8. Method according to any of the preceding claims, whereby for locally resolved tempering a heating array (1) formed from a plurality of heating elements (2) is used, whereby each heating element (2) is adjusted to a first temperature calculated dependent on a previous locally resolved measured value of the light efficiency.

9. Method according to any of the preceding claims, whereby a scanner (6) or a CCD camera is used for locally resolved measurement of the light efficiency.

10. Method according to any of the preceding claims, whereby the luminophore layer (4) is produced from a doped alkali halogenide.

11. Method according to claim 10, whereby the doped alkali halogenide is selected from the following group:

CsBr;

Eu, CsI;

Tl, CsI;

Na, RbBr;

Eu, RbBr;

Tl.

12. Device to implement the method according to any of the preceding claims, with a with the [sic] device (6) for locally resolved measurement of the light efficiency of a luminophore layer (4), a heating array (1) formed from a plurality of individually controllable heating elements (2), and a device (5) to control the heating elements (2) dependent on the measured values of the light efficiency.

13. Device according to claim 12, whereby an x-ray source (8) is provided to iradiate [sic] the luminophore layer (4).

14. Device according to claim 12 or 13, whereby the device (6) comprises a CCD camera or a scanner with LED elements for locally resolved measurement of the light efficiency.