# US 7,744,439 B2 · Image display device and manufacturing method of the same

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- Number: US 7,744,439 B2
- Document ID: US7744439B2
- Status: Granted
- Kind: B2
- Application number: 11/783,849
- Filed: 2007-04-12
- Published: 2007-09-13
- Granted: 2010-06-29
- Earliest claimed: 2002-11-29
- Assignees: Panasonic Corporation
- Inventors: Daisuke Adachi; Hiroyasu Tsuji; Keisuke Sumida
- Web page: https://patentgrep.com/patent/US7744439B2

## CPC

- H01J 9/241: {the vessel being for a flat panel display (H01J9/261 takes precedence; flat discharge lamps H01J9/248)}
- C03B 18/20: Composition of the atmosphere above the float bath; Treating or purifying the atmosphere above the float bath
- C03C 15/00: Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00)
- C03C 19/00: Surface treatment of glass, not in the form of fibres or filaments, by mechanical means (sand-blasting, grinding, or polishing glass B24)
- H01J 11/12: with main electrodes provided on both sides of the discharge space
- H01J 11/34: Vessels, containers or parts thereof, e.g. substrates
- H01J 11/44: Optical arrangements or shielding arrangements, e.g. filters, black matrices, light reflecting means or electromagnetic shielding means
- Y02P 40/57: Improving the yield, e-g- reduction of reject rates
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present invention provides an image display device capable of displaying a good image by suppressing yellowing of a glass substrate, and a high-yield manufacturing method of the glass substrate. The image display device is formed of a front-side glass substrate and a back-side glass substrate. In this manufacturing method, a glass substrate is used as the front-side glass substrate when Sn++ content in the glass substrate is a predetermined value or less, and the glass substrate is used as the back-side glass substrate when the Sn++ content exceeds the predetermined value.

## Claims

### Claim 1

A method of manufacturing an image display device having a front-side glass substrate and a back-side glass substrate, the front-side glass substrate and the back-side glass substrate being manufactured by a float method, the front-side glass substrate and the back-side glass substrate each having a surface on which an Ag electrode is to be formed, the method comprising:
measuring a reflectance of a surface of a glass substrate on which the Ag electrode is to be formed; and
selecting whether the glass substrate is to be used as the front-side glass substrate or the back-side glass substrate based on the measured reflectance,
wherein the measuring of the reflectance comprises measuring the reflectance at a wavelength maximizing a difference between a reflection spectrum at a wavelength of 200 nm˜250 nm on the surface of the glass substrate on which the Ag electrode is to be formed and a reflection spectrum at a wavelength of 200 nm˜250 nm at a part formed by removing no less than 15 μm˜20 μm from the surface, and wherein the selecting of the glass substrate comprises using the glass substrate as the back-side glass substrate when the measured reflectance exceeds 5%.