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US4082426A Expired / Lapsed US ⏱️ 0.0 years remaining

Retroreflective sheeting with retroreflective markings

Assignee: 3M Co
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Filing: 1976-11-26
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Granted: 1978-04-04
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Expires: 1996-11-26
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Abstract

Abstract Retroreflective sheeting is taught which incorporates markings that are distinctly visible when the sheeting is viewed at an angle under retroreflective viewing conditions, thereby allowing a viewer to determine the identity of the sheeting. The sheeting comprises a monolayer of microsphere-lenses; a spacing layer coated on the microsphere-lenses and contoured so as to generally follow the curved back surfaces of the microsphere-lenses; a specularly reflective layer coated over the spacing layer; and a transparent image layer disposed in an imagewise pattern between the spacing layer and specularly reflective layer, with the thickness of the image layer being greater in the valleys of the spacing layer between the microsphere-lenses than on the curved surfaces directly in back of the microsphere-lenses.

Inventors

  • 👤 Robert A. Brown

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 12:04
CPC Classifications
G; G06; G06K; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/14; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128; G09; G09F; G09F13/00; G09F13/16

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 132 words
Reflective sheeting comprising a monolayer of microsphere-lenses adapted to receive light rays incident on the front surface of the sheeting, a spacing layer of polymeric material covering the back surfaces of the microsphere-lenses and contoured so as to generally follow those back surfaces, a specularly reflective layer coated over the spacing layer, and an image layer disposed in an imagewise pattern between the spacing layer and specularly reflective layer; characterized in that the image layer is transparent and in that the thickness of the image layer is greater in the valleys of the spacing layer between the microsphere-lenses than on the curved surfaces directly in back of the microsphere-lenses, whereby the 45° retroreflection from the image areas of said sheeting is at least 30 percent less than the retroreflection from nonimage areas.
Claim 2
Dependent Claim 132 words
Reflective sheeting comprising a monolayer of microsphere-lenses adapted to receive light rays incident on the front surface of the sheeting, a spacing layer of polymeric material covering the back surfaces of the microsphere-lenses and contoured so as to generally follow those back surfaces, a specularly reflective layer coated over the spacing layer, and an image layer disposed in an imagewise pattern between the spacing layer and specularly reflective layer; characterized in that the image layer is transparent and in that the thickness of the image layer is greater in the valleys of the spacing layer between the microsphere-lenses than on the curved surfaces directly in back of the microsphere-lenses, whereby the 45° retroreflection from the image areas of said sheeting is at least 30 percent less than the retroreflection from nonimage areas.
Claim 3
Dependent Claim 30 words
Sheeting of claim 1 in which the image layer has a color different from the color of the spacing layer so that images are visible under ordinary daylight viewing conditions.
Claim 4
Dependent Claim 26 words
Sheeting of claim 1 in which the image layer has the same color as the spacing layer, whereby images are indiscernible under ordinary daylight viewing conditions.

References Cited (Backward Citations)

US3154872A Cited
US3795435A Cited
US3801183A Cited
US3994086A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-04-03 1981-10-03 1982-04-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-04-03 1985-10-03 1986-04-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-04-03 1989-10-03 1990-04-04 $7700.00 Window Closed / Lapsed

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