English Electric Valve Company Limited

Ralph D Nixon

A display arrangement consists of a tubular envelope with fluorescent stripes running along its length, localized portions of which are illuminated by different electron guns which produce flood beams of electrons. Field electrodes which surround each electron gun determine the angular direction at which the flood beam leaves the gun and hence which one of the fluorescent stripes is caused to emit light. The stripes can be of three different primary colors, to produce a colored display.

Display arrangements

A display arrangement consists of a tubular envelope with fluorescent stripes running along its length, localized portions of which are illuminated by different electron guns which produce flood beams of electrons. Each gun is situated within a switchable magnetic field which determines the angular direction at which the flood beam leaves the gun, and hence which one of the fluorescent stripes is caused to emit light. The stripes can be of three different primary colors, to produce a colored display.

A display arrangement particularly suitable for displaying video signals representing a thermal image. Successive horizontal lines of a television raster pattern are offset, or staggered, by a small amount so as to remove vertical stripe patterns which are caused by digital processing and storage of the video signal. This results in a much more acceptable visual display.

Display systems

A display arrangement utilizes a fluorescent screen 3 to provide readily alterable bright displays. The arrangement can provide a fairly large display surface, but can be of very small thickness. It contains electron emissive cathodes 5, and field electrodes 7 positioned closely adjacent to the cathode to control the emission of free electrons. Electrons which are freely emitted are accelerated to a mesh electrode 4 which is held at a modest positive voltage. A fluorescent screen 3 having a positive potential of several thousand volts is positioned closely in front of the mesh electrode. In preferred embodiments of the invention, a number of separate cathodes and/or separate field electrodes are provided, so that selected regions of the screen can be illuminated to provide desired display patterns. Individual regions of the screen can be switched on and off (i.e. rendered bright or dark) by the application of very low switching potentials to the field electrodes and/or the cathodes.

Fluorescent display arrangement having field electrode adjacent cathode

A display arrangement consists of one or more elongate display devices, each of which has a number of separately energizable display areas positioned along its length. When energized, each display area is seen as a bright patch of light. As it is very difficult to arrange that the display areas extend right to the extreme ends of the device, optical deflection means are positioned in front of the display areas to magnify the size of each so that the total display area extends over the whole length of the elongate display device. The optical deflection means is arranged so that each bright patch is of substantially the same size. The invention enables a large number of similar elongate display devices to be placed end to end while avoiding the appearance of periodic dark patches at the ends of adjacent devices.

A lamp consists of a high voltage power supply 5 mounted on an evacuated envelope 1. The lamp glows when electrons from a cathode 2 strike a phospher coating 4 on the inside surface of the envelope. The lamp is mounted so that it can be separated from the power supply and provision is made to inhibit the generation of the very high anode potential by the power supply unless it is correctly mounted on the envelope.

Lamps

A display arrangement is provided in the form of an elongate evacuated envelope (1) having a phosphor screen (11) which is capable of providing a very bright display. A number of mesh electrodes (6) are positioned side by side along the length of the envelope so as to selectively determine which portions of the phosphor screen emit light. By controlling the potential of the mesh electrodes, the display can be switched on and off rapidly to provide a versatile form of information display. A large number of evacuated envelopes can be assembled to form a two dimensional array and if desired a color display can be provided by using phosphor patched of different colors.

A display arrangement consists of a cathode ray tube in which electrons from a flood gun pass through a segmented mesh electrode, different portions of which can be selectively switched to enable the electrons to reach only selected portions of a fluorescent screen. As very low switching voltages are applied to the mesh electrode to control the passage of electrons from the flood gun, the cathode is heated to the temperature at which electrons are emitted by the application of relatively short high current pulses. Electrons are allowed to pass through the mesh electrode only during the intervals between these pulses.

A display arrangement is provided with two opposite display surfaces so that a display can be seen from both directions. The display arrangement consists of an evacuated envelope and fluorescent screens are provided at both display surfaces which are irradiated by a common electron emissive cathode. This enables a display arrangement to be provided which is very thin, but which is capable of providing very bright displays in an economical manner. Segmented mesh electrodes are positioned adjacent to both fluorescent screens so as to selectively control the regions of the screen which fluoresce, and this enables the nature of the display to be readily altered.

A rotatable thermal shutter for use with a pyroelectric camera tube is provided with blades having opening and closing edges in the shape of a spiral. The use of a spiral shape allows the rotatable shutter to have a particularly small diameter while still providing satisfactory performance.

Radiation shutters

A mesh electrode for a c.r.t. display device consists of a number of coplanar portions of mesh insulated from each other, and secured to a support plate by means of two layers of refractory compound. The first layer is applied to the support plate and allowed to set before the second layer is applied so as to space the mesh portions from the support plate by at least the thickness of the first layer.

Mesh electrodes and method of making them

The invention is concerned with monitoring the temperature distribution of a surface which may not be a good emitter of thermal radiation. In the invention a member which is of relatively low thermal conductivity and high thermal emissivity is placed in contact with the surface the temperature distribution of which it is required to monitor so that a thermal image transfers from the latter to the former. A pyroelectric vidicon camera tube then examines the temperature distribution of the member.

Methods and apparatus for examination of surface temperature distribution

An addressable display in which data is presented in the form of a rectangular dot array is provided by means of an evacuated cathode ray tube, which enables large bright displays to be achieved. The cathode ray tube contains two segmented mesh electrodes each consisting of separately addressable stripes. Electrons from a flood gun are passed by both electrodes only at the crossing point of two stripes, one on each electrode, when predetermined potentials are applied to them.

A mesh electrode for a c.r.t. display device consists of a number of coplanar portions of mesh insulated from each other and secured to a support plate by means of a refractory compound incorporating particles larger than the pitch of the mesh. These particles space the mesh away from the support plate and allow the electrode to be easily fabricated.

Mesh electrodes

A method of operating a storage tube having a secondary electron emissive storage target includes applying selected bias voltages to the target during the writing and erasure steps to control the electron emission ratio, which during writing is less than unity and which during erasure is greater than unity. This permits the voltage on the target during writing to be of the same order as the voltage present during reading, and this enhances the resolution and performance of the tube.

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Braintree, United Kingdom

Ralph D Nixon