A method for manufacturing a light distribution member has steps of providing a plurality of first light blocking film members, each of which including a first light blocking film covering a surface of a light-transmissive board, bonding a plurality of first light blocking film members, such that each first light blocking film is sandwiched between light-transmissive boards of adjacent first light blocking film members, to form a first bonded body, and cutting the first bonded body in a direction perpendicular to a lamination surface of the first light blocking film members so as to form a plurality of slices.

An organic light-emitting display device includes a pixel electrode, an emission layer on the pixel electrode, an opposing electrode covering the emission layer, a plurality of upper layers on the opposing electrode, light-shielding elements on the upper layers, and a color filter layer on the upper layers. The light-shielding elements include first light-shielding layers and second light-shielding layers. The first light-shielding layers include first materials, and the second light-shielding layers include second materials different from the first materials. The second light-shielding layers overlay the first light-shielding layers.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The marker can be revealed by exposure of the encrypted marker or a sample thereof to the developer in any suitable form, such as a solution, a slurry, a swab, a solid (such as in granular form), or a gas or a vapor that includes a developer.