Optical film and display device with narrow frame

A display device with narrow frame comprising:

• a plurality of display screens each comprising a display panel and a frame, the display panel comprising a center area and four boundaries surrounding the center area, the frame mounted to the boundaries;
• and
• a plurality of optical films each formed on one display screen and comprising four film portions connected to each other to form a hollow rectangle, each film portion covering one boundary and the frame mounted to the boundary, and comprising a plurality of strip-shaped micro-structures, each micro-structure having a triangular cross-section, and comprising a bottom surface, a first side surface, and a second side surface, the bottom surfaces of the micro-structures connected to each other, the first side surfaces and the second side surfaces of the micro-structures obliquely connected to each other, the second side surface of one micro-structure positioned at an outermost side of each film portion;
• wherein a first angle θ1 which is between the first side and bottom surface of each micro-structure is less than a second angle θ2 which is between the first side surface and the second side surface, and a sum of the first angle θ1 and the second angle θ2 is less than 90°, thus causing light from the display panel to be refracted by the first side surface and to be re-directed towards a connecting surface between two adjacent display screens.