Shadow mask for color CRT
US6664724B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 28, 2002 |
| Grant date | Dec 16, 2003 |
| Priority date | — |
| Expiry date | May 28, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/0788
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a shadow mask for a color cathode ray tube including a plurality of slots in which electron beams pass, a roughly rectangular-shaped effective surface having long sides and short sides and a skirt portion downwardly curved-extended from the outer surface of the effective surface, wherein a horizontal pitch at the central portion of a shadow mask satisfies a condition of W×0.08%≦Pho≦W×0.086% when a horizontal pitch at the central portion of a shadow mask slot is Pho, a screen effective surface long side length is W and the shadow mask central portion is placed on the center in which the shadow mask effective surface long side is divided into three equal parts. In addition, the shadow mask satisfies a condition of Pho×0.24≦Sw≦Pho×0.30 when a slot horizontal width at the shadow mask central portion is Sw. Accordingly, definition lowering occurred due to a screen horizontal pitch increase can be minimized and simultaneously color purity lowering according to a horizontal pitch decrease can be prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.