Patent · US Active

Retardation film, method for producing the same, polarizing plate and liquid crystal display

US7939002B2 · kind B2 · utility

2Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 4, 2006
Grant dateMay 10, 2011
Priority date
Expiry dateJan 17, 2028

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC09K2323/031
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A method of producing a long roll retardation film comprising the sequential steps of: (a) casting a film forming material on an endless support to form a long roll film; (b) stretching the long roll film in a lateral direction of the long roll film while both edges of the long roll film are held employing a plurality of clips for each of the edges in a tenter (First Process); (c) reducing distances in the lateral direction between the clips holding the both edges of the long roll film while the edges of the long roll film are held continuously from First Process with the clips (Second Process); (d) enlarging the distances in the lateral direction between the clips holding the both edges of the long roll film while the edges of the long roll film are held continuously from Second Process with the clips (Third Process).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.