US3659281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light pen tracking system
Assignee: NEC Corp
•
Filing: 1971-01-18
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Granted: 1972-04-25
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Expires: 1991-01-18
Abstract
Abstract A light pen tracking system in which the size of the tracking mark is varied depending on the range of vision as determined by the distance of the light sensitive tip of the light pen from the display surface.
Inventors
- 👤 Samio Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:58
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/038; G06F3/0386
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
136 words
A light pen tracking system comprising: a mark generator for generating a signal representative of a mark to be displayed; means for displaying said mark on one surface thereof in response to said signal; a light pen responsive to said mark displayed on said one surface of said displaying means for producing signals in the form of pulses; means coupled to said light pen for detecting the spatial deviation of the center coordinates of said mark with respect to the region of view of said light pen, said region depending on the distance of said light pen from said one surface; means for moving the center coordinate of said mark on said one display surface so as to reduce said deviation; and means for varying the size of said mark depending on said range of vision.
Claim 2
Dependent Claim
136 words
A light pen tracking system comprising: a mark generator for generating a signal representative of a mark to be displayed; means for displaying said mark on one surface thereof in response to said signal; a light pen responsive to said mark displayed on said one surface of said displaying means for producing signals in the form of pulses; means coupled to said light pen for detecting the spatial deviation of the center coordinates of said mark with respect to the region of view of said light pen, said region depending on the distance of said light pen from said one surface; means for moving the center coordinate of said mark on said one display surface so as to reduce said deviation; and means for varying the size of said mark depending on said range of vision.
Claim 3
Dependent Claim
40 words
The light pen tracking system as claimed in claim 1, in which said mark size varying means includes means for determining whether the center and end points of said mark are in the range of vision of said light pen.
Claim 4
Dependent Claim
78 words
The light pen tracking system as claimed in claim 2, in which said mark size varying means further comprises means coupled to said determining means for producing a logic signal of a first type when the center and end points of said mark are in the range of vision of said light pen, and a logic signal of a second type when the end points of said mark are beyond the range of vision of said light pen.
Claim 5
Dependent Claim
47 words
The light pen tracking system of claim 3, in which said mark size varying means further comprises means coupled to said mark generator responsive to a logic signal of one of said first and second types for producing a mark size select signal for said mark generator.
Claim 6
Dependent Claim
41 words
The light pen tracking system of claim 4, further comprising gating means interposed between said logic signal producing means and said mark size select producing means, and means responsive to a minimum mark size select signal for inhibiting said gating means.
References Cited (Backward Citations)
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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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |