Ribbon beam cathode ray tube

A cathode ray tube apparatus comprising:

• a cathode assembly emitting a ribbon beam of electrons propagating in a first direction, the electron distribution of the beam being substantially uniform across the width of the beam;
• a linear modulation assembly modulating the ribbon beam emitted from the cathode, the modulation assembly including conductive elements which are actively controlled to generate fields which impede propagation of select portions of the ribbon beam;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emissions of visible light from the display surface;
• a beam-directing electrode assembly which uniformly accelerates the electrons of the ribbon beam, directing the ribbon beam toward the display surface;
• a beam-focusing electrode assembly for providing focusing of the ribbon beam perpendicular to the plane of the ribbon beam;
• and
• an electrostatic velocity filter comprising a plurality of parallel velocity filter plates parallel to the propagation direction of the ribbon beam and perpendicular to the plane of the ribbon beam for removing electrons from the modulated ribbon beam, the removed electrons having unacceptably high velocities in a direction perpendicular to the beam propagation direction in the plane of the ribbon beam.

A cathode ray tube apparatus comprising:

• a cathode emitting a ribbon beam of electrons propagating in a first direction;
• a modulation assembly modulating the ribbon beam emitted from the cathode;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light form the display surface;
• a beam-directing electrode assembly which redirect the ribbon beam toward the display surface;
• a plurality of thin septa positioned within the cathode ray tube and aligned parallel with the direction of ribbon beam propagation the septa bracing tube surfaces from compressive forces on the tube wherein the thickness of each septum is tapered near the display surface such that the narrowest part of each septum contacts the display surface;
• and
• septum electrodes located along the tapered part of each septum to draw electrons toward the septum.

A cathode ray tube apparatus comprising:

• a cathode emitting a ribbon beam of electrons propagating in a first direction;
• a modulation assembly modulating the ribbon beam emitted from the cathode;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light from the display surface;
• a beam-directing electrode assembly which redirect the ribbon beam toward the display surface;
• a plurality of thin septa positioned within the cathode ray tube and aligned parallel with the direction of ribbon beam propagation, the septa bracing tube surfaces from compressive forces on the tube wherein the thickness of each septum is tapered near the display surface such that the narrowest part of each septum contacts the display surface;
• and
• feedback electrodes positioned along the tapered portion of each septum for measuring proximate electron beam position.

A cathode ray tube apparatus comprising:

• a cathode emitting a ribbon beam of electrons propagating in a first direction;
• a modulation assembly modulating the ribbon beam emitted from the cathode;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light form the display surface;
• a beam-directing electrode assembly which redirect the ribbon beam toward the display surface;
• a plurality of thin septa positioned within the cathode ray tube and aligned parallel with the direction of ribbon beam propagation the septa bracing tube surfaces from compressive forces on the tube wherein the thickness of each septum is tapered near the display surface such that the narrowest part of each septum contacts the display surface;
• septum electrodes located along the tapered part of each septum;
• and
• an electrostatic velocity filter comprising a plurality of parallel velocity filter plates parallel to the propagation direction of the ribbon beam and perpendicular to the plane of the ribbon beam for absorbing electrons of the ribbon beam which have relatively high velocities perpendicular to said first direction in the plane of the ribbon beam.

A cathode ray tube apparatus comprising:

• a cathode assembly emitting a ribbon beam of electrons propagating in a first direction, the electron distribution of the beam being substantially uniform across the width of the beam;
• a modulation assembly modulating the ribbon beam emitted from the cathode, the modulation assembly including conductive elements which are actively controlled to impede propagation of select portions of the ribbon beam;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light from the display surface;
• a beam-directing electrode assembly which uniformly accelerates the electrons of the ribbon beam, directing the ribbon toward the display surface;
• a plurality of thin septa positioned within the cathode ray tube and aligned parallel with the direction of ribbon beam propagation to brace tube surfaces from compressive forces on the tube, the septa being tapered near the display surface;
• and
• septum electrodes along the tapered region of each septum to draw electrons toward the tapered regions.

A cathode ray tube apparatus comprising;

• a cathode emitting a ribbon beam of electrons propagating in a first direction;
• a plurality of velocity filter plates perpendicular to the ribbon beam and parallel with the propagation direction of the ribbon beam, and through which portions of the ribbon beam must travel, each filter plate having an electrical potential sufficient to sustain absorption of most electron beam electrons coming in contact with it;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light from the display surface;
• and
• a beam-directing electrode assembly which directs the modulated ribbon beam toward the display surface.

A cathode ray tube apparatus comprising:

• a cathode assembly emitting a ribbon beam of electrons propagating in a first direction, the electron distribution of the beam being substantially uniform across the width of the beam;
• a linear modulation assembly comprising a grid of conductive elements through which the ribbon beam must pass, each conductive element affecting one individual portion of the ribbon beam;
• a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor coating causing the emission of visible light from the display surface;
• a beam-directing electrode assembly which directs the modulated ribbon beam toward the display surface, the electrode assembly being actively controlled to sweep the ribbon beam across the display surface to sequentially illuminate adjacent lines on the display surface;
• and
• an electrostatic velocity filter for absorbing ribbon beam electrons having unacceptably high velocities perpendicular to said first direction in the plane of the ribbon beam, the velocity filter comprising a plurality of parallel velocity filter plates parallel to the propagation direction of the ribbon beam and perpendicular to the plane of the ribbon beam.

A method of displaying a video image, the method comprising:

• providing a cathode ray tube having a cathode assembly emitting a ribbon beam in a first direction;
• modulating the ribbon beam with a linear modulation assembly;
• filtering the ribbon beam with an electrostatic velocity filter comprising a plurality of parallel velocity filter plates parallel to the propagation direction of the ribbon beam and perpendicular to the plane of the ribbon beam which absorb electrons of the ribbon beam having unacceptably high velocities perpendicular to said first direction in the plane of the ribbon beam;
• providing a phosphor-coated display surface upon which electrons of the ribbon beam are incident;
• and
• directing the modulated ribbon beam toward the display surface with a beam-directing electrode assembly.

A method of displaying a video image, the method comprising:

• providing a cathode ray tube having a cathode assembly emitting a ribbon beam in a first direction, the electron distribution of the beam being substantially uniform across the width of the beam;
• modulating the ribbon beam with a linear modulation assembly comprising a grid of conductive elements through which the ribbon beam must pass, each conductive element affecting one individual portion of the ribbon beam;
• providing a phosphor-coated display surface upon which electrons of the ribbon beam are incident, absorption of electrons by the phosphor-coating causing the emission of visible light from the display surface;
• focusing the ribbon beam perpendicular to the plane of the ribbon beam with a beam-focusing electrode assembly;
• directing the modulated ribbon beam toward the display surface with a beam-directing electrode assembly, the electrode assembly being actively controlled to sweep the ribbon beam across the display surface to sequentially illuminate adjacent lines on the display surface;
• and
• filtering the ribbon beam with an electrostatic velocity filter which absorbs ribbon beam electrons having unacceptably high velocities perpendicular to said first direction in the plane of the ribbon beam, the velocity filter comprising a plurality of parallel velocity filter plates parallel to the propagation direction of the ribbon beam and perpendicular to the plane of the ribbon beam.