US4957335A
Expired / Lapsed
US
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Microsphere-based retroreflective articles with enhanced retroreflective brightness
Assignee: 3M Co
•
Filing: 1989-05-26
•
Granted: 1990-09-18
•
Expires: 2009-05-26
Abstract
Abstract Microsphere-based retroreflective articles having exceptionally high retroreflective brightness, particularly at divergence angles of up to 0.5° may be made by selection of microspheres having defined combinations of average diameter and average refractive index.
Inventors
- 👤 Clark G. Kuney, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:21
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/136; G02B5/126; G02B5/128
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
80 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 2
Dependent Claim
80 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 3
Dependent Claim
30 words
The article of claim 1 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region C of FIG. 5.
Claim 4
Dependent Claim
30 words
The article of claim 1 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region B of FIG. 5.
Claim 5
Dependent Claim
30 words
The article of claim 1 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region A of FIG. 5.
Claim 6
Dependent Claim
22 words
The article of any one of claims 1-4 wherein said microspheres have a diameter percent range of about 20 percent or less.
Claim 7
Dependent Claim
22 words
The article of any one of claims 1-4 wherein said microspheres have a diameter percent range of about 10 percent or less.
Claim 8
Dependent Claim
33 words
The article of claim 1 wherein said article has an exposed-lens retroreflective brightness of at least about 800 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 9
Dependent Claim
33 words
The article of claim 1 wherein said article has an exposed-lens retroreflective brightness of at least about 1000 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 10
Dependent Claim
33 words
The article of claim 1 wherein said article has an exposed-lens retroreflective brightness of at least about 1300 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 11
Dependent Claim
30 words
The article of claim 1 wherein said microspheres have an average refractive index between about 1.930 and about 1.950 and an average diameter between about 90 and about 170 microns.
Claim 12
Dependent Claim
32 words
The article of claim 10 wherein said article has an exposed-lens retroreflective brightness of at least about 800 candela per lux per meter 2 at divergence angle of less than about 0.20°.
Claim 13
Dependent Claim
24 words
The article of claim 1 wherein said reflectors are selected from at least one of the following: specular reflectors, dielectric reflectors, and diffuse reflectors.
Claim 14
Dependent Claim
33 words
The article of claim 12 wherein said reflectors are specular reflectors and said microspheres have an average refractive index of about 1.940 and an average diameter between about 98 and about 161 microns.
Claim 15
Dependent Claim
16 words
The article of claim 13 wherein said reflectors comprise at least one of aluminum or silver.
Claim 16
Dependent Claim
33 words
The article of claim 12 wherein said reflectors are diffuse reflectors and said microspheres have an average refractive index of about 1.940 and an average diameter between about 129 and about 164 microns.
Claim 17
Dependent Claim
16 words
The article of claim 1 wherein at least a portion of said article is substantially planar.
Claim 18
Dependent Claim
15 words
The article of claim 1 wherein at least a portion of said article is contoured.
Claim 19
Dependent Claim
19 words
The article of claim 1 wherein at least a portion of said microspheres are arranged in substantially a monolayer.
Claim 20
Dependent Claim
18 words
The article of claim 1 wherein at least a portion of said microspheres are arranged in multi-layer fashion.
Claim 21
Dependent Claim
17 words
The article of claim 1 wherein at least a portion of said article is of exposed-lens construction.
Claim 22
Dependent Claim
17 words
The article of claim 1 wherein at least a portion of said article is of encapsulated-lens construction.
Claim 23
Dependent Claim
17 words
The article of claim 1 wherein at least a portion of said microspheres have different optical orientations.
Claim 24
Dependent Claim
13 words
The article of claim 1 wherein said microspheres have substantially uniform optical orientations.
Claim 25
Dependent Claim
39 words
The article of claim 1 wherein said reflectors are diffuse reflectors and said article has an exposed-lens retroreflective brightness of at least about 30 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 26
Dependent Claim
39 words
The article of claim 1 wherein said reflectors are diffuse reflectors and said article has an exposed-lens retroreflective brightness of at least about 45 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 27
Dependent Claim
31 words
The article of claim 1 wherein said reflectors are dielectric reflectors and said article has an exposed-lens retroreflective brightness of at least about 300 candela per lux per meter 2 .
Claim 28
Dependent Claim
31 words
The article of claim 1 wherein said reflectors are dielectric reflectors and said article has an exposed-lens retroreflective brightness of at least about 400 candela per lux per meter 2 .
Claim 29
Dependent Claim
86 words
A coating composition for forming retroreflective coatings, said composition comprising (1) transparent microspheres having substantially hemispheric reflectors thereon, (2) binder material, and (3) a volatilizing agent, wherein said microspheres have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 30
Dependent Claim
86 words
A coating composition for forming retroreflective coatings, said composition comprising (1) transparent microspheres having substantially hemispheric reflectors thereon, (2) binder material, and (3) a volatilizing agent, wherein said microspheres have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 31
Dependent Claim
80 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region E of FIG. 11, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 32
Dependent Claim
80 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region E of FIG. 11, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 33
Dependent Claim
72 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index between about 1.930 and about 1.950 and an average diameter between about 90 and about 170 microns, said article having an exposed-lens retroreflective brightness of at least about 800 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 34
Dependent Claim
72 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index between about 1.930 and about 1.950 and an average diameter between about 90 and about 170 microns, said article having an exposed-lens retroreflective brightness of at least about 800 candela per lux per meter 2 at a divergence angle of less than about 0.20°.
Claim 35
Dependent Claim
25 words
The article of claim 30 wherein said article has an exposed-lens retroreflect brightness of at least about 1000 candela per lux per meter 2 .
Claim 36
Dependent Claim
25 words
The article of claim 30 wherein said article has an exposed-lens retroreflective brightness of at least about 1300 candela per lux per meter 2 .
Claim 37
Dependent Claim
65 words
A microsphere-based retroreflective article having a surface region which comprises transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average diameter between about 110 and about 200 microns and an average refractive index between about 1.915 and about 1.950, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 38
Dependent Claim
65 words
A microsphere-based retroreflective article having a surface region which comprises transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average diameter between about 110 and about 200 microns and an average refractive index between about 1.915 and about 1.950, and wherein said microspheres have a diameter percent range of about 30 percent or less.
Claim 39
Dependent Claim
68 words
A variable contrast sign having a background area and a legend area wherein said background area comprises transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average diameter between about 110 and about 200 microns and an average refractive index between about 1.915 and about 1.950, said background area and said legend area having different divergence profiles.
Claim 40
Dependent Claim
68 words
A variable contrast sign having a background area and a legend area wherein said background area comprises transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average diameter between about 110 and about 200 microns and an average refractive index between about 1.915 and about 1.950, said background area and said legend area having different divergence profiles.
Claim 41
Dependent Claim
65 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5.
Claim 42
Dependent Claim
65 words
A microsphere-based retroreflective article comprising transparent microspheres having reflectors in optical association with the rear surfaces thereof, wherein said microspheres are air-incident, and have an average refractive index of at least about 1.915 and an average diameter of at least about 75 microns, said average refractive index and said average diameter also corresponding to the coordinates of a point within region D of FIG. 5.
Claim 43
Dependent Claim
30 words
The article of claim 35 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region C of FIG. 5.
Claim 44
Dependent Claim
30 words
The article of claim 35 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region B of FIG. 5.
Claim 45
Dependent Claim
30 words
The article of claim 35 wherein said microspheres have an average refractive index and an average diameter corresponding to the coordinates of a point within region A of FIG. 5.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |