| 摘要 |
PROBLEM TO BE SOLVED: To efficiently reflect incident light entering in oblique direction of reflector body and at the same time, to reflect reflected light at a relatively wide visual field angle, by growing minute cracks in the thickness direction of an amorphous transparent resin sheet and adding a flat mirror to one surface of the above resin sheet. SOLUTION: When a sheet-type amorphous transparent resin 1 is brought into contact with an org. solvent or with the vapor of an org. solvent which is a bad solvent for the resin while the resin sheet is deformed under large bending stress of stretched stress in one direction, cracks appear in an almost perpendicular direction to the stress direction and lots of minute cracks grow parallel to each other in a thickness direction. By laminating a flat mirror 3 to the back surface of this synthetic resin sheet 1, light beams with which the upper surface of the sheet is irradiated in obliquely upper direction, are specifically reflected in the incident direction on the surface having cracks. These cracks 2 can be formed in a thermoplastic amorphous transparent resin sheet, plate or film which is so-called a glass resin such as styrene having 5μm to 5mm thickness. |
