In recent years, the thinning of an image display apparatus, in particular, an image display apparatus for mobile applications has been progressing, and hence there has been a growing requirement for the thinning of a polarizing plate to be used in the image display apparatus. As a method of thinning the polarizing plate, there is given, for example, a method involving thinning a polarizer (polarizing film) itself, or arranging a protective film for protecting the polarizer only on one side of the polarizer (e.g., Patent Literature 1 and Patent Literature 2). A polarizing plate having a protective film arranged only on one side thereof, i.e., a polarizing plate including a polarizer and the protective film arranged on one side of the polarizer (hereinafter sometimes referred to as “one-side protected polarizing plate”) is used as described below. A pressure-sensitive adhesive layer is directly formed on the polarizer, and the polarizing plate is laminated on any other member.
Meanwhile, the use of an optical laminate, which includes a lamination of an absorption-type polarizing plate and a reflection-type polarizing plate functioning as a brightness enhancement film, has been proposed for the purpose of improving the brightness of an image display apparatus (e.g., Patent Literature 3). Also in such optical laminate, for achieving its thinning, the use of the one-side protected polarizing plate as the absorption-type polarizing plate is conceivable.
USPTO Backgrounds
USPTO Backgrounds