US3778658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multibeam cathode ray tube utilizing d.a.m. grid
Assignee: General Electric Co
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Filing: 1972-09-01
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Granted: 1973-12-11
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Expires: 1992-09-01
Abstract
Abstract An electron gun within a glass envelope generates a sheet electron beam which is focussed into a line on a phosphor screen positioned at the output end of the glass envelope. A plurality of parallel metal plates oriented in planes defined by the scan direction and normal to the phosphor screen are positioned within the glass envelope in close proximity to the phosphor screen. The plates are in the direct path of the sheet beam and result in the beam being divided into a plurality of parallel beams of number one less than the plurality of plates. Input signals simultaneously applied to the plates produce intensity modulation of the electron beams by generating electrostatic fields between adjacent plates in accordance with the input signal voltages and thereby control or modulate the fraction of each beam that passes between adjacent plates and reaches the screen. The plates thus function as a divide and modulate (D.A.M.) grid. Deflection coils or plates positioned between the electron gun and D.A.M. grid simultaneously deflect the sheet beam and resultant modulated beams in the scan (beam sweep) direction whereby the input signals can be simultaneously displayed on the screen.
Inventors
- 👤 L Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:54
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/48; H01J29/488; H01J31/00; H01J31/08; H01J31/10; H01J31/12; H01J2229/00; H01J2229/48; H01J2229/50; H01J2229/507
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
335 words
A multibeam visual display device comprising means for generating a sheet electron beam, a phosphor screen positioned in alignment with said sheet electron beam generating means and spaced a substantial distance therefrom in the direction of electron beam emission therefrom, means positioned between said phosphor screen and said sheet electron beam generating means for accelerating the electrons in the sheet beam and focussing the beam on said phosphor screen, a grid consisting of a plurality of superposed parallel electrically conductive plates positioned between said accelerating and focussing means and said phosphor screen and aligned therewith, said parallel plates oriented normal to the plane of the sheet beam and parallel to the device center-line axis defined by the aligned center-line axes of said sheet beam generating means and said phosphor screen whereby the sheet beam in its passage through said grid is divided into a plurality of parallel electron beams of number one less than the plurality of plates, said grid positioned in close proximity to said phosphor screen and adapted to have electrical input signals applied thereto from a plurality of signal sources such as simultaneously responsive transducers of number equal to the plurality of electron beams, said signal sources providing the electrical input signals which are in time-spaced form and which intensity modulate the electron beams in their passage within the grid, and means positioned between said accelerating and focussing means and said grid for deflecting the sheet beam in a direction perpendicular to the plane of the sheet beam in its nondeflected state to thereby simultaneously deflect the plurality of intensity modulated electron beams in a like direction and thereby form on said phospor screen a raster of a like plurality of simultaneously generated sweep lines intensity modulated by the electrical input signals to form a resultant visual image corresponding to the input signals wHerein the spacings between intensity modulated points along each sweep line are in accordance with the time-spacings of the signals provided by a corresponding one of the signal sources.
Claim 2
Dependent Claim
335 words
A multibeam visual display device comprising means for generating a sheet electron beam, a phosphor screen positioned in alignment with said sheet electron beam generating means and spaced a substantial distance therefrom in the direction of electron beam emission therefrom, means positioned between said phosphor screen and said sheet electron beam generating means for accelerating the electrons in the sheet beam and focussing the beam on said phosphor screen, a grid consisting of a plurality of superposed parallel electrically conductive plates positioned between said accelerating and focussing means and said phosphor screen and aligned therewith, said parallel plates oriented normal to the plane of the sheet beam and parallel to the device center-line axis defined by the aligned center-line axes of said sheet beam generating means and said phosphor screen whereby the sheet beam in its passage through said grid is divided into a plurality of parallel electron beams of number one less than the plurality of plates, said grid positioned in close proximity to said phosphor screen and adapted to have electrical input signals applied thereto from a plurality of signal sources such as simultaneously responsive transducers of number equal to the plurality of electron beams, said signal sources providing the electrical input signals which are in time-spaced form and which intensity modulate the electron beams in their passage within the grid, and means positioned between said accelerating and focussing means and said grid for deflecting the sheet beam in a direction perpendicular to the plane of the sheet beam in its nondeflected state to thereby simultaneously deflect the plurality of intensity modulated electron beams in a like direction and thereby form on said phospor screen a raster of a like plurality of simultaneously generated sweep lines intensity modulated by the electrical input signals to form a resultant visual image corresponding to the input signals wHerein the spacings between intensity modulated points along each sweep line are in accordance with the time-spacings of the signals provided by a corresponding one of the signal sources.
Claim 3
Dependent Claim
68 words
The multibeam visual display device set forth in claim 1 and further comprising a sealed tubular member having input and output ends and fabricated of an electrically nonconductive and nonmagnetic material, said sheet electron beam generating means supported within said tubular member adjacent the input end thereof, said phosphor screen supported within said tubular member at the output end thereof, and said grid supported within said tubular member.
Claim 4
Dependent Claim
39 words
The multibeam visual display device set forth in claim 1 wherein said accelerating and focussing means is of the electrostatic type and is adapted to be operated at relatively high positive potentials relative to said sheet beam generating means.
Claim 5
Dependent Claim
31 words
The multibeam visual display device set forth in claim 2 wherein said electron beam deflecting means is of the electromagnetic type and is supported around the outside of said tubular member.
Claim 6
Dependent Claim
28 words
The multibeam visual display device set forth in claim 2 wherein said electron beam deflecting means is of the electrostatic type and is supported within said tubular member.
Claim 7
Dependent Claim
84 words
The multibeam visual display device set forth in claim 2 and further comprising a plurality of electrically conductive terminals equal in number to the plurality of grid plates and passing through a side wall of said tubular member, and a like plurality of insulated electrical conductors having first ends connected to corresponding said grid plates and having second ends connected to corresponding said terminals whereby the plurality of input signals are applied to said grid plates by means of said terminals and electrical conductors.
Claim 8
Dependent Claim
25 words
The multibeam visual display device set forth in claim 6 wherein said plurality of terminals are symmetrically arranged around the circumference of said tubular member.
Claim 9
Dependent Claim
36 words
The multibeam visual display device set forth in claim 2 wherein said sealed tubular member is fabricated of glass and is evacuated to a relatively low pressure in the order of 10 5 torr or lower.
Claim 10
Dependent Claim
87 words
The multibeam visual display device set forth in claim 1 wherein said grid consists of at least 21 equally spaced apart said plates, and the resultant visual image formed on said phosphor screen in the case of the simultaneously responsive transducers corresponds to sensed time-spaced signals received thereby and converted into the time-spaced electrical input signals wherein the spacings between intensity modulated points along each sweep line are in accordance with the times of arrival of the sensed time-spaced signals at a corresponding one of the transducers.
Claim 11
Dependent Claim
46 words
The multibeam visual display device set forth in claim 1 and further comprising a fine mesh grid positioned between said parallel plate grid and said phosphor screen for preventing slow secondary electrons which may be generated in said parallel plate grid from reaching said phosphor screen.
Claim 12
Dependent Claim
22 words
The multibeam visual display device set forth in claim 1 wherein the grid plates are closely spaced in equally spaced apart relationship.
Claim 13
Dependent Claim
20 words
The multibeam visual display device set forth in claim 1 wherein the grid plates are each of the same size.
Claim 14
Dependent Claim
19 words
The multibeam visual display device set forth in claim 1 wherein the grid plates are each of rectangular shape.
Claim 15
Dependent Claim
101 words
The multibeam visual display device set forth in claim 1 wherein the grid plates are operated at a median D.C. potential substantially equal to the D.C. potential of said phosphor screen relative to said sheet beam generating means, said grid plates are each of the same size and in equally spaced apart relationship, and the length dimension L of each grid plate is determined from the equation VD/VO 4d2/L2 wHere d is the spacing between adjacent plates, VD is the deflection voltage between adjacent grid plates, and VO is the median D.C. potential of the grid plates relative to the cathode.
References Cited (Backward Citations)
US2449339A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |