| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve the problem in an internal total reflection type reflective device wherein light made incident at a comparatively large angle (incident angle) on an optical axis of a device composing a retroreflective device is transmitted without satisfying a reflection condition, and thereby the intensity of retroreflected light is reduced, i.e. to improve the problem (incident angle characteristic) that the intensity of retroreflected light is remarkably reduced according to the increase in an incident angle. <P>SOLUTION: In a retroreflective sheet having a retroreflective device layer comprising many cube corner type retroreflective devices, a refractive index adjusting agent is added to a retroreflective device material composing the retroreflective device layer. <P>COPYRIGHT: (C)2009,JPO&INPIT |
