US Patent 11061176 Polarizer, polarizing plate, and image display apparatus

A polarizer that can realize the multi-functionalization and high-functionalization of an electronic device, such as an image display apparatus. A polarizer including a resin film containing a dichroic substance, wherein the polarizer has a low dichroic substance concentration portion whose content of the dichroic substance is relatively low in the resin film. In the polarizer, the low dichroic substance concentration portion has a content of an alkali metal and/or an alkaline earth metal of 3.6 wt % or less.