US4424449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shielded fluorescent signs
Assignee: Individual
•
Filing: 1981-07-29
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Granted: 1984-01-03
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Expires: 2001-07-29
Abstract
Abstract A sign includes fluorescent pigment-containing indicia protected from fading from solar ultraviolet radiation by a transparent, ultraviolet-absorbing shield spaced apart therefrom. An artificial source of ultraviolet radiation is interposed between the indicia and the shield, and permits excitation of the fluorescence for nightime use of the sign.
Inventors
- 👤 Robert A. O'Brill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:00
CPC Classifications
G; G09; G09F; G09F13/00; G09F13/20; G09F13/04; G09F13/0418; G09F13/0472
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
160 words
A sign, comprising: indicia means containing a fluorescent pigment for rendering said indicia highly visible in daylight ambient conditions; means at least partially translucent to visible radiation and at least partially opaque to ultraviolet radiation, spaced apart in front of said indicia means for shielding thereof from solar ultraviolet radiation impinging on said indicia means to prevent or at least to retard greatly the fading of said fluorescent pigment in said indicia means during daylight ambient conditions and for permitting the observation thereof by visible radiation in daylight ambient conditions; and radiation means disposed in front of said indicia means and interposed between said shielding means and said indicia means for producing rearwardly directed ultraviolet radiation and for causing said radiation to impinge directly on said indicia means without passing through said shielding means to cause said fluorescent pigment to fluoresce in low light ambient conditions to produce forwardly directed visible radiation passing through said shielding means toward an observer.
Claim 2
Dependent Claim
160 words
A sign, comprising: indicia means containing a fluorescent pigment for rendering said indicia highly visible in daylight ambient conditions; means at least partially translucent to visible radiation and at least partially opaque to ultraviolet radiation, spaced apart in front of said indicia means for shielding thereof from solar ultraviolet radiation impinging on said indicia means to prevent or at least to retard greatly the fading of said fluorescent pigment in said indicia means during daylight ambient conditions and for permitting the observation thereof by visible radiation in daylight ambient conditions; and radiation means disposed in front of said indicia means and interposed between said shielding means and said indicia means for producing rearwardly directed ultraviolet radiation and for causing said radiation to impinge directly on said indicia means without passing through said shielding means to cause said fluorescent pigment to fluoresce in low light ambient conditions to produce forwardly directed visible radiation passing through said shielding means toward an observer.
Claim 3
Dependent Claim
24 words
The sign of claim 1 further including support means, and means for holding releasably said indicia means in overlaying relationship on said support means.
Claim 4
Dependent Claim
42 words
The sign of claim 2 further including means for mounting said radiation means intermediate said indicia means and said means for shielding to cause radiation from said radiation means to impinge on said indicia means without passing through said means for shielding.
Claim 5
Dependent Claim
20 words
The sign of claim 1, wherein said means for shielding includes a transparent sheet of material containing ultraviolet radiation absorbers.
Claim 6
Dependent Claim
26 words
The sign of claim 4, wherein said means for shielding includes laminated glass including a layer of glass and a layer of ultraviolet radiation-absorbing plastic material.
Claim 7
Dependent Claim
16 words
The sign of claim 4, wherein said shielding means comprises plastic material containing ultraviolet radiation absorbers.
Claim 8
Dependent Claim
13 words
The sign of claim 6, wherein said plastic material is an acrylic material.
Claim 9
Dependent Claim
46 words
The sign of claim 5, further including hollow frame means having said radiation means mounted therein, said means for shielding being mounted on the front portion thereof and said indicia means being mounted on the rear thereof, means for sealing said frame in a water-tight manner.
Claim 10
Dependent Claim
22 words
The sign of claim 9, wherein said frame means includes closure means for permitting access to the interior of said frame means.
Claim 11
Dependent Claim
29 words
The sign of claim 8, further including opaque means disposed at the front portion of said frame means for blocking solar ultraviolet radiation from impinging on said indicia means.
References Cited (Backward Citations)
US3525864A
Cited
US4016450A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |