Abstract: A projection screen and a projection system. The projection screen includes a reflection layer and a light absorption layer for absorbing light which are sequentially arranged from an incident side of projection light; the reflection layer comprises multiple microstructure units; each microstructure unit comprises a first plane and a second plane which are opposite to each other at an angle in a first direction as well as a third plane and a fourth plane which are opposite to each other at an angle in a second direction.

Abstract: A light-shielding frame and an LED display device are provided and respectively has excellent light-shielding performance and optical display performance. The light-shielding frame includes a retaining wall and hollow grids; the retaining wall includes first and second retaining walls connected in a stacked manner along a light-emitting direction of the grids, and each grid includes first and second grid portions. The thickness of the first retaining wall decreases from one end thereof close to the second retaining wall to the other end thereof distant from the second retaining wall to form a first draft angle; the thickness of the second retaining wall decreases from one end thereof close to the first retaining wall to the other end thereof distant from the first retaining wall to form a second draft angle; the first retaining wall has the same thickness as the second retaining wall in the connection position thereof.

Abstract: A projection screen and a projection system. The projection screen includes a reflection layer and a light absorption layer for absorbing light which are sequentially arranged from an incident side of projection light; the reflection layer comprises multiple microstructure units; each microstructure unit comprises a first plane and a second plane which are opposite to each other at an angle in a first direction as well as a third plane and a fourth plane which are opposite to each other at an angle in a second direction.