A cathode ray tube has an evacuated shallow envelope provided with a flat screen, and an electron gun is arranged to direct an electron beam into the envelope from one edge thereof in a direction which is substantially parallel to the plane of the screen. The beam is deflected by controlled deflection electrodes towards the screen to control the distance from said edge at which the beam impinges on the screen. An electrode arrangement is provided in the envelope for deflecting the beam towards the screen by an amount which increases with increasing distance from said edge of the envelope In this way the angle of attack of the beam on the screen at all positions along the screen is greater than it would be in the absence of the electrode arrangement. A grid may be arranged in the envelope parallel to an immediately behind the screen, the grid being connected to a D.C. source such that the angle of attach of the electron beam relative to the screen is further increased as the beam passes through the grid.
A fluorescent display device is disclosed which is capable of improving visibility of luminous display of anodes. In the device, cathodes are arranged laterally out of an area opposite to the anodes so as not to hinder the observation of the luminous display. The device also includes a deflecting electrode for deflecting and diffusing electrons emitted from the cathodes so as to direct them toward the anodes.
An evacuated envelope has a rectangular display section and a gun section at one edge of the display section. The display section includes front and back walls which are generally rectangular, in closely spaced, parallel relation, and a plurality of spaced, parallel support walls between the front and back walls forming a plurality of parallel channels. The gun section extends across one end of the channels and includes therein gun structure which will direct electrons into the channels. In each of the channels is a beam guide which confines the electrons in a beam and guides the beam along the length of the channel. The beam guide also includes means for selectively deflecting the electron beam out of the guide at selective points along the guide so that beam will impinge upon a phosphor screen along the inner surface of the front wall. In each of the channels is a scanning deflector which deflects the path of the beam as it passes from the guide to the phosphor screen so that each of the beams will scan a portion of the phosphor screen.
A cathode ray tube which comprises: an evacuated envelope having at least one transparent flat portion, a fluorescent target arranged on the inner surface of the flat portion, an electron gun within the envelope in laterally spaced relation to the target for emitting an electron beam along a path parallel with the surface of the flat portion, a first deflecting device comprising the target, and an opposite electrode in the envelope for impinging the electron beam upon the target, a second deflecting device comprising a pair of plates to control the electron beam passing therebetween and arranged in the envelope for deflecting the electron beam perpendicularly to the surface of the flat portion, the pair of plates being connected with the opposite electrode and the anode electrode of the electron gun, respectively, and a vertical deflection signal being applied to the anode electrode, and a third deflecting device arranged adjacent to the envelope in cooperation with the pair of plates for concentrating deflecting flux generated by means of the third device on the electron beam between the pair of plates for deflecting the electron beam in parallel with the surface of the flat portion and generally transverse to the direction of the electron beam, thereby to produce an image on the target.
The display tube includes an electron gun (29) which directs a low energy electron beam (30) generally parallel to a flat faceplate (14) carrying a phosphor screen (16). The beam is deflected in a plane parallel to the faceplate by deflection electrodes (38) for line scanning purposes before being reversed in direction by a reversing lens (40) and then scanned framewise over the input side of an electron multiplier (44) by further deflection electrodes (42). The low energy beam in the scanning section of the tube is susceptible to the influence of ambient magnetic fields. The ensure that the beam correctly enters the reversing lens (40) in its acceptance window regardless of such fields an electron-optic lens system (50) defining a series of alternate high and low voltage regions and constituting in effect a series of relay lenses is provided between the gun and the reversing lens which periodically re-focusses the beam and constrains the beam substantially along a predeterming path with respect to the reversing lens.
A cathode ray tube includes an electron gun directing electrons towards a faceplate having an electrode biased at screen potential. The electron beam is magnetically deflected to scan across the faceplate to impinge upon phosphors thereon to produce light depicting an image or information. A neck electrode near the tube neck is biased at or below screen potential and a second electrode between the neck electrode and the faceplate is biased at or above screen potential. As a result, the electrons are deflected over a greater total angle than is obtained from the magnetic deflection. A third electrode proximate the faceplate is biased at or below screen potential to direct electrons towards the faceplate, thereby to increase the landing angle of the electrons thereon. A metal and ceramic support includes a resistive voltage divider to which ones of the electrodes connect.
