Flat cathode ray tube and method of operation

Claim 1

A method for displaying optical information in a flat cathode ray tube comprising the steps of providing a flat cathode ray tube leaving an evacuated container having a front and back wall which are parallel to each other, said front wall supporting a cathodo-luminescent layer and a flatly extending acceleration anode, said back wall having a flatly extending back electrode, said container in a plane extending parallel to the front and back walls and sub-dividing the chamber into a back chamber and a front chamber being provided with a substrate having a plurality of parallel extending conductive strips forming at least one group of row conductors facing the back electrode and on a surface opposite the row conductors being provided with a plurality of parallel conductor strips extending perpendicular to the direction of the row conductors to form column conductors, said substrate being provided with apertures disposed in the row conductors, said cathode ray tube being provided with an electron source extending along one side wall of the container parallel to the row conductors, said electron source including one emission cathode as well as one attraction anode to produce a flat electron beam having a width which extends the entire length of the row conductors, extends parallel to the row conductors, and projects the beam obliquely into the back chamber, said tube including a beam guidance electrode with an equal potential extending in a plane parallel to the back wall between the row conductor and the back electrode; controlling the potentials applied on the back electrodes, the acceleration anode, the emission cathode, the attraction anode, the beam guidance electrode and the row conductors to project a flat beam from the electron source obliquely into the back chamber to travel in a sinuous path with a wavelength and with penetration of the plane of the beam guidance electrode at least once prior to penetrating a selected row conductor and to penetrate successively selected row conductors, said controlling including applying a base potential to the cathode, applying a potential more positive than the base potential to the beam guidance electrode, applying potentials more negative than the base potential to the back electrode and to at least all of the row conductors located between a selected row conductor and the cathode, and raising the potential on each selected row coneuctor to be ≧ to the base potential to move the selected row conductors along the row conductive successively; changing the wavelength of the sinuous path of the flat beam in a saw tooth manner so that the flat beam strikes each row conductor of the group of conductors after travelling the same number of half wavelengths and after leaving the sinuous path at the same phase of the path, said changing of the wavelength includes modulating the potential applied to at least one of the back electrodes, beam guidance electrode, non-selected row conductors and the attraction anode in a saw tooth manner; and providing selected signal voltages to the column conductors to selectively block the passage of the electron beam through space points of the selected row conductor and enable passage at other points so that the electron beam strikes selected points of a row of points on the cathodo-luminescent layer associated with the selected row conductor.

Claim 2

A method for displaying optical information in a flat cathode ray tube comprising the steps of providing a flat cathode ray tube leaving an evacuated container having a front and back wall which are parallel to each other, said front wall supporting a cathodo-luminescent layer and a flatly extending acceleration anode, said back wall having a flatly extending back electrode, said container in a plane extending parallel to the front and back walls and sub-dividing the chamber into a back chamber and a front chamber being provided with a substrate having a plurality of parallel extending conductive strips forming at least one group of row conductors facing the back electrode and on a surface opposite the row conductors being provided with a plurality of parallel conductor strips extending perpendicular to the direction of the row conductors to form column conductors, said substrate being provided with apertures disposed in the row conductors, said cathode ray tube being provided with an electron source extending along one side wall of the container parallel to the row conductors, said electron source including one emission cathode as well as one attraction anode to produce a flat electron beam having a width which extends the entire length of the row conductors, extends parallel to the row conductors, and projects the beam obliquely into the back chamber, said tube including a beam guidance electrode with an equal potential extending in a plane parallel to the back wall between the row conductor and the back electrode; controlling the potentials applied on the back electrodes, the acceleration anode, the emission cathode, the attraction anode, the beam guidance electrode and the row conductors to project a flat beam from the electron source obliquely into the back chamber to travel in a sinuous path with a wavelength and with penetration of the plane of the beam guidance electrode at least once prior to penetrating a selected row conductor and to penetrate successively selected row conductors, said controlling including applying a base potential to the cathode, applying a potential more positive than the base potential to the beam guidance electrode, applying potentials more negative than the base potential to the back electrode and to at least all of the row conductors located between a selected row conductor and the cathode, and raising the potential on each selected row coneuctor to be ≧ to the base potential to move the selected row conductors along the row conductive successively; changing the wavelength of the sinuous path of the flat beam in a saw tooth manner so that the flat beam strikes each row conductor of the group of conductors after travelling the same number of half wavelengths and after leaving the sinuous path at the same phase of the path, said changing of the wavelength includes modulating the potential applied to at least one of the back electrodes, beam guidance electrode, non-selected row conductors and the attraction anode in a saw tooth manner; and providing selected signal voltages to the column conductors to selectively block the passage of the electron beam through space points of the selected row conductor and enable passage at other points so that the electron beam strikes selected points of a row of points on the cathodo-luminescent layer associated with the selected row conductor.