US3879611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Luminescent backing sheet for writing in the dark
Assignee: Individual
•
Filing: 1974-08-19
•
Granted: 1975-04-22
•
Expires: 1994-08-19
Abstract
Abstract A lined phosphorescent backing sheet for use in underlying relation with writing paper or drawing sheets permitting a writer to write in orderly lined form in the dark without need for external light.
Inventors
- 👤 Becky J Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:19
CPC Classifications
F; F21; F21K; F21K2/00; B; B43; B43L; B43L3/00; B43L3/001; B43L3/002
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
82 words
A luminescent backing sheet assembly for guiding the application of matter on writing sheets in darkness comprising; a backing sheet having a luminescent surface, an overlay sheet of material through which luminescent light can pass overlying said backing sheet, said overlay sheet having areas of light contrasting material which in combination with the luminescent surface of said backing sheet provide a visible contrast in the dark defining a guide for application of intelligible material to sheets placed over the backing sheet aSsembly.
Claim 2
Dependent Claim
82 words
A luminescent backing sheet assembly for guiding the application of matter on writing sheets in darkness comprising; a backing sheet having a luminescent surface, an overlay sheet of material through which luminescent light can pass overlying said backing sheet, said overlay sheet having areas of light contrasting material which in combination with the luminescent surface of said backing sheet provide a visible contrast in the dark defining a guide for application of intelligible material to sheets placed over the backing sheet aSsembly.
Claim 3
Dependent Claim
82 words
A luminescent backing sheet assembly for guiding the application of matter on writing sheets in darkness comprising; a backing sheet having a luminescent surface, an overlay sheet of material through which luminescent light can pass overlying said backing sheet, said overlay sheet having areas of light contrasting material which in combination with the luminescent surface of said backing sheet provide a visible contrast in the dark defining a guide for application of intelligible material to sheets placed over the backing sheet aSsembly.
Claim 4
Dependent Claim
82 words
A luminescent backing sheet assembly for guiding the application of matter on writing sheets in darkness comprising; a backing sheet having a luminescent surface, an overlay sheet of material through which luminescent light can pass overlying said backing sheet, said overlay sheet having areas of light contrasting material which in combination with the luminescent surface of said backing sheet provide a visible contrast in the dark defining a guide for application of intelligible material to sheets placed over the backing sheet aSsembly.
Claim 5
Dependent Claim
20 words
A backing sheet assembly according to claim 1 wherein the light contrasting material of said overlay sheet is opaque material.
Claim 6
Dependent Claim
35 words
A backing sheet assembly according to claim 2 wherein said luminescent sheet has non-luminescent areas which cooperate with the opaque areas of said overlay sheet in guiding the application of intelligible matter to writing sheets.
Claim 7
Dependent Claim
35 words
A backing sheet assembly according to claim 1 wherein the light contrasting material of said light passing overlay sheet is luminescent material which will emit light of different color from that of said luminescent surface.
Claim 8
Dependent Claim
22 words
A backing sheet assembly according to claim 1 wherein the backing sheet assembly includes a transparent top sheet overlying said overlay sheet.
Claim 9
Dependent Claim
34 words
A backing sheet assembly according to claim 5 wherein said top sheet and luminescent surface sheet are secured together at one edge which acts as a guide stop for insertion of said overlay sheet.
Claim 10
Dependent Claim
14 words
A backing sheet assembly according to claim 1 wherein said backing sheet is flexible.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |