Device and method for inspecting liquid crystal stain of polarizing plate

A device for inspecting a liquid crystal stain of a polarization plate, comprising:

• a surface light source;
• a first polarization member disposed such that light is applied thereto from the surface light source;
• a polarization plate disposed such that the light transmitted through the first polarization member is applied thereto, and reflecting the applied light;
• a second polarization member disposed such that the light reflected from the polarization plate is applied thereto;
• and
• an inspection source disposed such that the light transmitted through the second polarization member is applied thereto, and determining liquid crystal stains of the polarization plate based on the light transmitted through the second polarization member,
• wherein the polarization plate sequentially comprises a protective film, a polarizer and a quarter wave plate,
• wherein the quarter wave plate comprises a liquid crystal film,
• wherein the liquid crystal film sequentially comprises a base film and a liquid crystal layer,
• wherein the light transmitted through the first polarization member is applied to the quarter wave plate of the polarization plate,
• wherein the light transmitted, from the surface light source, through the first polarization member and linearly polarized is transmitted through the quarter wave plate of the polarization plate and circularly polarized, and the circularly polarized light is incident on the polarizer of the polarization plate, and the circularly polarized light incident on an interface between the protective film and the polarizer of the polarization plate is reflected from right circularly polarized light to left circularly polarized light or from left circularly polarized light to right circularly polarized light, and the reflected light is transmitted through the quarter wave plate of the polarization plate and is incident on the second polarization member,
• wherein the first polarization member has an absorption axis perpendicular to an absorption axis of the polarizer of the polarization plate, and
• wherein the second polarization member has an absorption axis parallel to the absorption axis of the polarizer of the polarization plate.