Polarizing plate and liquid crystal display

• US 8,400,592 B2
• Filed: 06/15/2011
• Issued: 03/19/2013
• Est. Priority Date: 02/28/2006
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Hirakata, Junichi, Wada, Minoru, Saitoh, Yukito, Ohashi, Yusuke, Ohmuro, Katsufumi
• Primary Examiner(s): PEACE, RHONDA S
• Application Number:
  US13/161,005
• Publication Number:
  US 20110242462A1
• Time in Patent Office: 643 Days
• Field of Search: 349/85, 349/112, 349/114, 349/117, 349/118
• US Class Current: 349/117
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 27/281 used for attenuating light intensity, e.g. comprising rotatable polarising elements
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: G02F 2202/40 Materials having a particular birefringence, retardation
• CPC Class Codes: G02F 2413/04 Number of plates greater than or equal to 4
• CPC Class Codes: G02F 2413/08 with a particular optical axis orientation
• CPC Class Codes: G02F 2413/105 with varying inclination in thickness direction, e.g. hybrid oriented discotic LC

Abstract

A polarizing plate for a liquid crystal display is provided and includes a first protective film, a polarizer, a second protective film and a light diffusion layer in order. The light diffusion layer is a layer including a translucent resin and translucent particles having a refractive index different from a refractive index of the translucent resin. The internal haze of the light diffusion layer is 45% to 80%.

Claims

1. A liquid crystal display comprising:

a pair of polarizing plates, each comprising a polarizer and a transparent layer, transmission axes of the pair of polarizing plates being perpendicular to each other; and

a liquid crystal panel between the pair of polarizing plates, wherein the liquid crystal panel comprises a pair of substrates disposed opposite to each other, one of the pair of substrates having an electrode on one side thereof, a liquid crystal layer including liquid crystal molecules aligned by alignment axes of opposite surfaces of the pair of substrates, and a pair of optically anisotropic layers, the liquid crystal layer being between the pair of optically anisotropic layers

wherein the liquid crystal panel has a double symmetrical axis with respect to a cubic structure defined by;

upper and lower alignment control directions of the liquid crystal layer which are defined by the alignment axes of opposite surfaces of the pair of substrates; and

alignment control directions of the pair of optically anisotropic layers, the double symmetrical axis being parallel to the surfaces of the pair of substrates, a transmission axis of one of the pair of polarizing plates is parallel to the double symmetrical axis, and a transmission axis of the other of the pair of polarizing plates is perpendicular to the double symmetrical axis, and

wherein the transparent layer between the liquid crystal layer and the polarizer is a biaxial retardation layer, and an in-plane retardation axis perpendicular to an absorption axis of the polarizer closer to the biaxial retardation layer.

2. The liquid crystal display according to claim 1, wherein the biaxial retardation layer has an NZ value of 0.1 to 0.4, wherein Nz=(nx−

nz)/(nx−

ny), nx represents a refractive index in a retardation axis direction in plane, ny represents a refractive index in a direction perpendicular to nx in plane, and nz represents a refractive index in a direction perpendicular to nx and ny.

3. The liquid crystal display according to claim 1, wherein the biaxial retardation layer has an in-plane retardation of 20 to 80 nm.

4. The liquid crystal display according to claim 1, wherein the biaxial retardation layer has an in-plane retardation of 0 to 70 nm.

5. The liquid crystal display according to claim 1, wherein at least one of the polarizing plates further comprises a light diffusion layer, wherein the light diffusion layer comprises a translucent resin and translucent particles having a refractive index different from that of the translucent resin, and the light diffusion layer has an internal haze of 45 to 80%.

6. The liquid crystal display according to claim 1, wherein one of the pair of polarizing plates includes a retardation layer, and the retardation layer is disposed between the polarizer of the one of the pair of polarizing plates and the liquid crystal panel.