Display device, light diffusion member having adhesive layer, and manufacturing method therefor

A light diffusion member (7) has a substrate (39) that is optically transparent, a light diffusion part (40) on the surface of the substrate (39) facing a display medium (6), and a light-shielding layer (41) in a region of the surface of the substrate (39) facing the display medium (6) other than the light diffusion part (40). The light diffusion part (40) has a light-emitting end face (40a) adjoining the substrate (39), and a light-incident end face (40b) that faces the light-emitting end face (40a) and has a larger area than that of the light-emitting end face (40a). The light-emitting end face (40a) adheres to an adhesive layer (42), a portion (42a) of the adhesive layer (42) penetrating into a space (43) formed between the light diffusion part (40) and the light-shielding layer (41). The distance T 1 leading from the surface of the substrate (39) facing the display medium (6) to the light-incident end face (40b) is greater than the distance (T 2 ) leading from the surface of the substrate (39) facing the display medium (6) to the surface of the adhesive layer (42) inside the space (43) (i.e., T 1 > T 2 ).