Patent US3576574A successfully refreshed from Google Patents.
US3576574A
Expired / Lapsed
US
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Light pen tracking unit with alternative tracking patterns
Assignee: International Business Machines Corp
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Filing: 1968-01-15
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Granted: 1971-04-27
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Expires: 1988-01-15
Abstract
Abstract Apparatus for use in conjunction with a CRT DISPLAY and LIGHT PEN for changing tracking modes when light pen motion is detected. It also relates to such apparatus for dynamically altering the tracking pattern dependent upon the detected speed of light pen travel. That is, the size of the tracking pattern may vary depending on the speed of the light pen.
Inventors
- 👤 Herbert B Baskin
- 👤 Robert H Riekert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:30
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/038; G06F3/0386
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
164 words
In a CRT display device including means for deflecting the cathode ray beam in accordance with data supplied thereto to produce visible patterns on the face of the cathode ray tube, and a light pen attachment including means for indicating when the light pen is in use and means for indicating when the light pen has intersected a visible pattern on the face of the CRT tube, the improvement which comprises a light pen tracking system including: means for establishing a first tracking pattern mode of operation producing a first tracking pattern under conditions of no detected light pen motion, means for establishing a second tracking pattern mode of operation different from the first mode producing a second tracking pattern when motion of the light pen is detected, and means for continuing operation of the second mode until the light pen intersects the pattern whereby the size of the second pattern will vary in accordance with the speed of motion of said light pen.
Claim 2
Dependent Claim
164 words
In a CRT display device including means for deflecting the cathode ray beam in accordance with data supplied thereto to produce visible patterns on the face of the cathode ray tube, and a light pen attachment including means for indicating when the light pen is in use and means for indicating when the light pen has intersected a visible pattern on the face of the CRT tube, the improvement which comprises a light pen tracking system including: means for establishing a first tracking pattern mode of operation producing a first tracking pattern under conditions of no detected light pen motion, means for establishing a second tracking pattern mode of operation different from the first mode producing a second tracking pattern when motion of the light pen is detected, and means for continuing operation of the second mode until the light pen intersects the pattern whereby the size of the second pattern will vary in accordance with the speed of motion of said light pen.
Claim 3
Dependent Claim
68 words
A CRT display system as set forth in claim 1 wherein said patterns are comprised of a plurality of line segments including means for optically sensing when the light pen intersects a particular line segment of the tracking pattern and for generating a light pen detect signal in accordance therewith, and means operative upon the occurrence of said detect signal for disabling further generating of the second pattern.
Claim 4
Dependent Claim
97 words
A CRT display system as set forth in claim 2 wherein said means for establishing the first tracking pattern includes means for generating and displaying at least one closed polygon on the face of said CRT display, and said means for establishing the second tracking pattern includes means for generating and displaying additional closed polygons substantially concentric to that generated by said last named means and wherein during a first mode of operation said tracking system displays only said first tracking pattern and during a second mode of operation displays both said first and second tracking patterns.
Claim 5
Dependent Claim
22 words
A CRT display system as set forth in claim 3 wherein both said first and second tracking patterns comprise regular closed polygons.
Claim 6
Dependent Claim
33 words
A CRT display system as set forth in claim 3 wherein the spacing between any two adjacent polygons of said tracking patterns is less than the field of view of the light pen.
Claim 7
Dependent Claim
80 words
A CRT display system as set forth in claim 3 wherein the polygons comprising the tracking pattern are constructeD of successively generated straight line segments beginning at an origin point on the inner most polygon, means operable upon the occurrence of a light pen detect signal for deriving the coordinate addresses of the last-generated line segment and means for modifying said address in a predetermined manner for generating the coordinate addresses of the origin point for the next tracking pattern.
Claim 8
Dependent Claim
73 words
A CRT display system as set forth in claim 6 wherein the means for modifying the address in a predetermined fashion includes a list of address correction factors and means for determining the particular tracking pattern polygon and the particular line segment within said polygon which was detected by said light pen, said determination being affective to extract a particular member of said correction list and for gating same to said modifying means.
Claim 9
Dependent Claim
27 words
A CRT display system as set forth in claim 7 wherein the modifying means comprises an adder for modifying both the X and Y coordinates when required.
Claim 10
Dependent Claim
66 words
A CRT display system as set forth in claim 8 wherein said CRT display is generated by incrementally moving the cathode ray beam from a current X-Y coordinate to another X-Y coordinate supplied to the CRT display deflection circuitry, and wherein the pattern generation means sequentially supplies a list of deflection increments to said CRT display system to generate the desired first and second tracking patterns.
Claim 11
Dependent Claim
43 words
A CRT display system as set forth in claim 9 wherein the tracking system controls includes a basic timing circuit comprising a set of latches wherein the setting of successive latch positions causes the generation of successive line segments of said display pattern.
Claim 12
Dependent Claim
145 words
A CRT display system as set forth in claim 10 wherein said tracking pattern system includes first and second operating mode latches only one of which may be in an active state at any one time including means for activating the first operating mode latch upon completion of said second tracking pattern without the occurrence of a light pen detect signal and means for maintaining said first operating mode latch in its active state until a light pen detect signal is detected, means for activating said second operation mode latch upon initiation of the tracking pattern generation system or upon the occurrence of a light pen detect signal while said first operating mode latch is in its active state, and means for maintaining activation of said second operation mode latch as long as a light pen detect signal is received during the tracking pattern generation.
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |