Claims
- 1. A triangular-pyramidal cube-corner retroreflective sheet characterized in that triangular-pyramidal cube-corner retroreflective elements protruded on one common base plane (X-X') are arranged on said base plane (X-X') in a close-packed state so as to face each other by sharing one common base edge on said base plane (X-X') with each other, the base plane (X-X') is one common plane including a plurality of base edges (x, x, . . . ) shared by said triangular-pyramidal retroreflective elements, two these triangular-pyramidal retroreflective elements facing each other form an element pair of substantially same shapes facing each other so as to be respectively substantially symmetric to planes (Y-Y', Y-Y', . . . ) vertical to said base plane (X-X') including said common base edges (x, x, . . . ) on said base plane (X-X'), said triangular-pyramidal retroreflective elements are formed with substantially same pentagonal lateral faces (c.sub.1, c.sub.2) using said common base edges (x, x, . . . ) as one side and substantially same quadrangular lateral faces (a.sub.1, b.sub.1 ; a.sub.2, b.sub.2) substantially perpendicularly intersecting said face c.sub.1 or c.sub.2 using two upper sides of said face c.sub.1 or c.sub.2 using apexes (H.sub.1, H.sub.2) of said triangular-pyramidal retroreflective elements as starting points as one side respectively, sharing one of ridge lines of said triangular-pyramidal retroreflective elements and using said ridge line as one side and the height (h') from the apexes (H.sub.1, H.sub.2) of said triangular-pyramidal retroreflective elements up to said base plane (X-X') including the base edges (x, x, . . . ) of the pentagonal lateral faces (c.sub.1, c.sub.2) of said triangular-pyramidal retroreflective elements is substantially larger than the height (h) from the apexes (H.sub.1, H.sub.2) of said triangular-pyramidal retroreflective elements up to a substantially horizontal plane (virtual plane Z-Z') including base edges (z, w) of other lateral faces (a.sub.1, b.sub.1 ; a.sub.2, b.sub.2) of said triangular-pyramidal retroreflective elements.
- 2. A triangular-pyramidal cube-corner retroreflective sheet characterized in that triangular-pyramidal cube-corner retroreflective elements protruded on one common base plane (X-X') are arranged in a close-packed state so as to face each other by sharing one common base edge on said base plane (X-X'), said base plane (X-X') is a common plane including the base edges (x, x, . . . ) shared by said triangular-pyramidal reflective elements, two these triangular-pyramidal reflective elements facing each other form a pair of substantially-same-shape elements facing each other so as to be respectively substantially symmetric to planes (Y-Y', Y-Y', . . . ) vertical to said base plane (X-X') including said common base edges (x, x, . . . ) on said base plane (X-X'), lateral faces (c.sub.1, c.sub.2) of said triangular-pyramidal reflective elements using said common base edges (x, x, . . . ) as one side are continuously arranged along said common base edges (x, x, . . . ) by respectively forming a substantially same pentagon, two other lateral faces (a.sub.1, b.sub.1 and a.sub.2 b.sub.2) constituting said triangular-pyramidal reflective elements respectively form a substantially same quadrangular lateral face using the two upper sides of said face c.sub.1 or c.sub.2 using the apexes (H.sub.1, H.sub.2) of said triangular-pyramidal reflective elements as starting points as one side and sharing one of the ridge lines of said triangular-pyramidal reflective elements and using said ridge line as one side, a plane (virtual plane Z-Z') including base edges (z, w) of said lateral faces (a.sub.1, b.sub.1) formed by the fact that the lateral faces (a.sub.1, b.sub.1) of said quadrangle intersect the corresponding quadrangular lateral face (a.sub.2 or b.sub.2) of other triangular-pyramidal reflective elements adjacent to said lateral faces (a.sub.1, b.sub.1) is substantially parallel with said base plane (X-X') and located substantially upper than the base plane (X-X'), and the optical axis of said triangular-pyramidal reflective elements forms at least an angle of 3.degree. from said vertical plane (Y-Y') in the direction in which the difference (q-p) between the distance (q) from the intersection between the optical axis of said triangular-pyramidal reflective elements and said base plane (X-X') up to the base edges (x, x, . . . ) shared by said element pair and the distance (p) from the intersection (P) between a perpendicular extended from the apexes (H.sub.1, H.sub.2) of said elements to said base plane (X-X') and said base plane (X-X') up to the base edges (x, x, . . . ) shared by said elements becomes plus.
- 3. The cube-corner retroreflective sheet according to claim 1 or 2, wherein the value of h'/h ranges between 1.05 and 1.5 when assuming the height of apexes (H.sub.1, H.sub.2) of triangular-pyramidal cube-corner retroreflective elements from the base plane (X-X') of said elements as h' and the height of said apexes (H.sub.1, H.sub.2) from said virtual plane (Z-Z') as h.
- 4. The cube-corner retroreflective sheet according to claim 1 or 2, wherein the value of h'/h ranges between 1.07 and 1.4 when assuming the height of apexes (H.sub.1, H.sub.2) of triangular-pyramidal cube-corner retroreflective elements from the base plane (X-X') of said elements as h' and the height of said apexes (H.sub.1, H.sub.2) from said virtual plane (Z-Z') as h.
- 5. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the optical axis a triangular-pyramidal reflective element tilts by 4.degree. to 12.degree. from said vertical plane (Y-Y') in a direction in which the difference (q-p) between the distance (p) from the intersection (P) between a perpendicular extended from apexes (H.sub.1, H.sub.2) of triangular-pyramidal cube-corner retroreflective elements to a base plane (X-X') and said base plane (X-X') up to one of the base edges (x, x, . . . ) shared by said element pair and the distance (q) from the intersection (Q) between the optical axis of said triangular-pyramidal reflective elements and said base plane (X-X') up to the base edges (x, x, . . . ) shared by said element pair become plus.
- 6. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the optical axis a triangular-pyramidal reflective element tilts by 5.degree. to 10.degree. from said vertical plane (Y-Y') in a direction in which the difference (q-p) between the distance (p) from the intersection (P) between a perpendicular extended from apexes (H.sub.1, H.sub.2) of triangular-pyramidal cube-corner retroreflective elements to a base plane (X-X') and said base plane (X-X') up to one of the base edges (x, x, . . . ) shared by said element pair and the distance (q) from the intersection (Q) between the optical axis of said triangular-pyramidal reflective elements and said base plane (X-X') up to the base edges (x, x, . . . ) shared by said element pair become plus.
- 7. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the distance (h) from a plane (virtual plane Z-Z') including a plurality of base edges (z, w) of quadrangular lateral faces (a.sub.1, b.sub.1 or a.sub.2, b.sub.2) formed by the fact that the substantially same quadrangular lateral faces (a.sub.1, b.sub.1) sharing one of ridge lines starting with apexes (H.sub.1, H.sub.2) of a plurality of triangular-pyramidal cube-corner retroreflective elements protruded onto a common base plane (X-X') as one side intersect the corresponding quadrangular lateral face (a.sub.2 or b.sub.2) of their adjacent other triangular-pyramidal reflective element up to the apexes (H.sub.1, H.sub.2) of said triangular-pyramidal reflective element ranges between 50 .mu.m and 400 .mu.m.
- 8. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the distance (h) from a plane (virtual plane Z-Z') including a plurality of base edges (z, w) of quadrangular lateral faces (a.sub.1, b.sub.1 or a.sub.2, b.sub.2) formed by the fact that the substantially same quadrangular lateral faces (a.sub.1, b.sub.1) sharing one of ridge lines starting with apexes (H.sub.1, H.sub.2) of a plurality of triangular-pyramidal cube-corner retroreflective elements protruded onto a common base plane (X-X') as one side intersect the corresponding quadrangular lateral face (a.sub.2 or b.sub.2) of their adjacent other triangular-pyramidal reflective element up to the apexes (H.sub.1, H.sub.2) of said triangular-pyramidal reflective element ranges between 60 .mu.m and 200 .mu.m.
- 9. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the magnitude of at least one prism face angle formed by the fact that three lateral faces (a.sub.1, b.sub.1, c.sub.1) or (a.sub.2, b.sub.2, c.sub.2) of a triangular-pyramidal cube-corner retroreflective element intersect each other is kept in a range of 89.5.degree. to 90.5.degree..
- 10. The cube-corner retroreflective sheet according to any one of claims 1 or 2, wherein the magnitude of at least one prism face angle formed by the fact that three lateral faces (a.sub.1, b.sub.1, c.sub.1) or (a.sub.2, b.sub.2, c.sub.2) of a triangular-pyramidal cube-corner retroreflective element intersect each other is kept in a range of 89.7.degree. to 90.3.degree..
Priority Claims (1)
Number |
Date |
Country |
Kind |
8-295907 |
Oct 1996 |
JPX |
|
Parent Case Info
This is the Section 371 National Phase application of International Application PCT/JP97/03743, filed Oct. 16, 1997.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/JP97/03743 |
10/16/1997 |
|
|
6/18/1998 |
6/18/1998 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/18028 |
4/30/1998 |
|
|
US Referenced Citations (17)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0137736 |
Apr 1985 |
EPX |
0548280 |
Jun 1993 |
EPX |
44-13395 |
Jun 1969 |
JPX |
50-47591 |
Apr 1975 |
JPX |