U.S. Philips Corporation

Roger Pook

Derek Washington

Martin John Edwards

Alan G Knapp

Hewson Nicholas King

Daphne L Lamport

Pieter Schagen

Pamela May Stubberfield

A matrix display device comprises a row and column array of picture elements (12) each of which consists of a display element (14), e.g. a LC display element, connected in series with a two-terminal non-linear device 15, such as a MIM, between associated row and column address conductors (16,17) to which selection and data signals are applied by a scanning signal drive circuit (20) and a data signal drive circuit (22) respectively, and a reference element circuit (34), comprising a non-linear device (35) in series with a capacitor (36), forming part of a feedback arrangement through which picture element drive voltages are controlled (25) so as to compensate for the effects of aging of the non-linear devices. The reference circuit is driven like the picture elements, with a scanning signal waveform and voltage signal (V.sub.A) applied to opposite sides, and the picture element drive voltages are adjusted in accordance with predetermined changes in the voltage across the capacitor (36). The reference non-linear device (35) can be provided on the same support (10 ) as the picture element devices (15). The capacitor (36) can be constituted by an electro-optic element corresponding to the display elements (14). A plurality of such reference circuits may be employed, extending in one or more rows and driven by row and column conductors.

Matrix display device and its method of operation

The image contrast in an image display tube having a channel plate electron multiplier (2) is improved by preventing secondary electrons emitted from the face of an input dynode (26) from straying to channels located at a relatively large distance from their origin. This is done by disposing a grid (24) at a short distance from the input dynode (26). If the grid (24) is held at a positive voltage relative to the input dynode (26), stray secondary electrons will be attracted toward the grid (24). Alternatively, if the grid (24) is held at a negative voltage relative to that of the input dynode (26), the secondary electrons will be induced to enter channels close to their origin.

Image display tube having a channel plate electron multiplier

A channel plate electron multiplier having channels which rapidly decrease in cross-section away from the input aperture and a conductive structure extending across the input aperture to flatten any fringing electrostatic field, resulting in an electrostatic field configuration which causes secondary emitted electrons to collide with the same side of the channel.

Electron multipliers having tapered channels

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East Grinstead, United Kingdom

Roger Pook