US4246033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement for applying written or drawn information onto image carriers for overhead projection
Assignee: Pelikan Produktions AG
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Filing: 1977-10-31
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Granted: 1981-01-20
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Expires: 1997-10-31
Abstract
Abstract Arrangement for applying written or drawn information onto image carriers for overhead projectors, characterized by an image carrier in film or plate form which comprises at least one colored compound, as well as a writing or drawing marker. The writing or drawing fluid of the marker contains at least one colorless compound which reacts with the colored compound to produce a color change.
Inventors
- 👤 Rene von Wartburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:28
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/136; Y; Y10; Y10T; Y10T428/00; Y10T428/31504
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
72 words
A combination for transmitting information with overhead projectors, said combination comprising: (a) a carrier including at least one color producing material which provides a first color to said carrier, and (b) marking means containing a colorless material which transfers to the carrier upon contact of the marking means with the carrier, (c) said colorless material being effective to react with said color producing material to change said first color to another color.
Claim 2
Dependent Claim
72 words
A combination for transmitting information with overhead projectors, said combination comprising: (a) a carrier including at least one color producing material which provides a first color to said carrier, and (b) marking means containing a colorless material which transfers to the carrier upon contact of the marking means with the carrier, (c) said colorless material being effective to react with said color producing material to change said first color to another color.
Claim 3
Dependent Claim
27 words
The combination as defined in claim 1 wherein the carrier includes a substrate having a film disposed thereon, said color producing material is located in said film.
Claim 4
Dependent Claim
16 words
The combination as defined in claim 2 wherein said color producing material is a colored compound.
Claim 5
Dependent Claim
20 words
The combination as defined in claim 3 wherein said colored compound includes an indicator dye or mixture of indicator dyes.
Claim 6
Dependent Claim
19 words
The combination as defined in claim 1 wherein the colorless material includes diluted solution of an acid or alkali.
Claim 7
Dependent Claim
34 words
The combination as defined in claim 1 wherein the color producing the material is a blue compound and the colorless material is effective to react with the blue compound to form a yellow color.
Claim 8
Dependent Claim
46 words
The combination as defined in claim 1 wherein the color producing material includes a dye having the formula: ##STR2## wherein R 1 is hydrogen or methyl, R 2 is hydrogen, methyl, bis-(carboxymethyl)-aminomethyl, chlorine or bromine, and R 3 is hydrogen, methyl, isopropyl, bis-(carboxymethyl)-aminomethyl, chlorine or bromine.
References Cited (Backward Citations)
US3501838A
Cited
US3672842A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |