An organic thin film structure is formed on a surface of a glass substrate. At least two color resist blocks are formed by patterning. A recess is formed between the two adjacent color resist blocks. Each of the color resist blocks has a lower color resist layer and an upper color resist layer formed on a surface of the lower color resist layer. A boundary of the upper color resist layer and a boundary the lower color resist layer are connected, and an angle between the boundaries and the surface of the glass substrate ranges from 10° to 60°.