The Secretary of State for Defence in Her Britannic Majesty's Government

Other

The Secretary of State for Defense in Her Britannic Majesty's Government

John R Banbury

Derek L Barter

John D Leyland

David N Jeenes

Helmet-mounted optical systems

Focusing means for cathode ray tubes

An EHT power supply, for example for a cathode ray tube, having a voltage multiplier of a multi-stage Cockroft-Walton type, in which the capacitors of each stage are formed by layers of conducting material juxtaposed on either side of a layer of dielectric material, the layers of dielectric material forming an integral part of the mechanical structure of the multiplier and physically supporting the rectifier diodes of the multiplier. In one embodiment of the invention, the multiplier is formed as a closely-spaced stack in which each stage comprises a separate layer of dielectric material, and in another embodiment the capacitors of the AC side of the multiplier are formed on one layer of material and the capacitors of the DC side of the multiplier are formed on another layer, the two layers being disposable on opposite sides of the neck of a cathode ray tube with the successive stages being longitudinally disposed along the neck.

High voltage power supply

Head-up display

The gun comprises a cathode, a control grid, a first anode a second anode and a third anode. Preferably a beam width limiting aperture is provided in the first anode. In one example the current modulating voltage applied to the grid is 0 to -50V, the voltage applied to the first anode is +5 kV, the focus voltage applied to the second anode is +500V, and the EHT voltage applied to the third anode is +25 kV. A main focussing lens is formed by the second and third anodes, but the spacing of the first and third anodes is small so that the focussing effect is also substantially dependent on the voltage of the first anode. The field strength between the grid and first anode is high, which combined with the high first voltage produces a small crossover.

Beam focusing means for a CRT electron gun assembly

An optical system for a head-up display for example for producing a collimated image of a crt display on the external view of an aircraft pilot includes an optical relay unit including two elements (11,12) to produce a double fold in its optical axis to reduce the physical size of the relay unit. One of the two units (11), preferably of a diffractive type, is adapted to transmit light of the display color at a first angle of incidence and to reflect such light at a second angle of incidence. By use of a diffractive element having a narrow band reflectance, the system is extended to include embodiments for combining the display of two different color displays and a full color version using three crts is described.

Optical system for head-up displays

In a display system light from an object (14) is deflected on to a collimator (16) and superimposed on an external view through a combiner (10) from an observing position (11). Relay optics (17) in the path of light from the object (14) has spaced apart elements (L.sub.1,L.sub.2) which produce first and second exit pupils (P.sub.1, P.sub.2). Exit pupil volumes (V.sub.1, V.sub.2) overlap to give an extended field of biocular view. The restricted field of view associated with prior art display systems is overcome since the present system provides a large field of view at the observing position (11), while system components fit within aircraft space constraints, such as windshield (19), fairing (33) and ejection line (20). Space remains available for other instrumentation, such as a second display CRT (45).

Display systems

A head up display system including a light emissive object at an object plane and a collimator and combiner to provide a collimated image for viewing at an eye plane overlaid on a view through the combiner. The object emits light in at least two chromatically separated emission wavebands and by a diffractive optical element in the light path from object plane to eye plane having narrow band reflection characteristics at each emission wavelength.

Growing community of inventors

Fleet, United Kingdom

John R Banbury