OPAQUE PLATE, DISPLAY BOARD, AND DISPLAY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an opaque plate, a display board, and a display system capable of obtaining such a visual effect that a pattern to be visually recognized can be changed according to an illumination condition, an observation position or the illumination condition and the observation position, without depending on a display panel which has a number of restrictions.SOLUTION: An opaque plate 10 and a display board 20 include an antireflection minute ruggedness formed region 2A and an antireflection minute ruggedness non-formed region 2B which are formed in a pattern shape on at least one surface 1a of an opaque substrate 1. The antireflection minute ruggedness formed region includes antireflection minute ruggedness 3. The antireflection minute ruggedness is formed of a minute protrusion group 4G that is an assembly of a large number of minute protrusions 4, and a maximum inter-protrusion distance Dmax of minute protrusions with respect to a maximum wavelength λmax of visible light satisfies Dmax≤λmax. Preferably, the minute protrusion group includes a high/low minute protrusion group in which a low-height minute protrusion is surrounded by a high-height minute protrusion. The display system includes this display board and a light source lighting up the display board.