Key with selective symbol display

Claim 2

A key for introducing data, comprising a display (31) defined by a matrix of electrically activatable areas (36) for displaying a symbol representative of the data, characterised by a control microcircuit (40) provided with output conductors (41, 42) connected to the areas (36) of the matrix for activation thereof and input conductors (45, 46) which can be connected to a selector circuit (50) for modifying the symbol displayed by the matrix.

Claim 3

A key according to claim 1, characterised by a base plate (27), a movable part (24) which is activatable by means of finger operation and fixing elements fixing the display (31) to the movable part.

Claim 4

A key for introducing data, comprising a support means (23, 27), a switch (29, 28) actuable to connect two conductors of the support means and a part (24) which is movable with respect to the support means and which can be finger-operated to actuate the switch and define an item of data associated with the actuated key, characterised by a display (31) having a matrix of areas (36) which is carried by the movable part of the key and a microcircuit (40) which is also carried by the movable part, in which the areas of the display have an electrically switchable optical state and in which the microcircuit comprises output conductors (41, 42) connected to the display for selective switching of the areas and input conductors (45, 46) connected to the support means (23, 22) and actuable by a selector circuit (50) to define a symbol represented by matrix and associated with the item of data which can be introduced by the key.

Claim 5

A key for introducing data, comprising a support means (23, 27), a switch (29, 28) actuable to connect two conductors of the support means and a part (24) which is movable with respect to the support means and which can be finger-operated to actuate the switch and define an item of data associated with the actuated key, characterised by a display (31) having a matrix of areas (36) which is carried by the movable part of the key and a microcircuit (40) which is also carried by the movable part, in which the areas of the display have an electrically switchable optical state and in which the microcircuit comprises output conductors (41, 42) connected to the display for selective switching of the areas and input conductors (45, 46) connected to the support means (23, 22) and actuable by a selector circuit (50) to define a symbol represented by matrix and associated with the item of data which can be introduced by the key.

Claim 6

A key according to claim 3, characterised in that the display (31) comprises a flat support means of which an upper part (32) can be observed and in which the microcircuit (40) is carried by the lower part (33) of the flat support means and the output conductors (41, 42) of the microcircuit are integrated on the flat support means.

Claim 7

A key according to any of the preceding claims, characterised in that the input conductors (45, 46) define the symbol to be displayed by means of serialised date.

Claim 8

A key according to any of the preceding claims, characterised in that the selector circuit (50) generates data signals of autosynchronous type and the microcircuit (40) comprises a decoder for extracting the clock signals from the data signals.

Claim 9

A key according to claim 5 or 6, characterised in that the microcircuit (40) receives its feed voltage by means of a circuit element (Fig. 7) connected to a single data conductor (CK/D).

Claim 10

A key according to any of the preceding claims, characterised in that the optical state of the areas (36) of the display (31) is provided with a memory effect.

Claim 11

A key according to any of claims 1 to 7, characterised in that the microcircuit (40) comprises a memory (80) having locations for storing signals associated with the states of activation of the display areas (36) and a circuit for storing the signals associated with a fresh state of activation of the areas in an initialisation phase for the key.

Claim 12

A key according to claim 1, 2 or 3, characterised by a flat cable (234) having input cable conductors (236) to receive selection information and feed signals , and display output cable conductors (233) to be connected with the display (231), and in that the microcircuit (246) is supported by cable and the input conductors of the microcircuit are electrically connected with the display output cable conductors.

Claim 13

A key according to claim 10, characterised in that the flat cable (234) comprises an upper portion (248) supporting the micro­circuit (246) and an intermediate bent portion (242) deformable upon depression of the key, and by means (251, 252) which prevent the upper portion being deformed upon depression of the key.

Claim 14

A key according to claim 5, characterised in that each microcircuit (246) comprises an output control circuit (292) and a data output conductor (274) connected with the output control circuit and in that, for the displaying of the characters, the input conductor (273) of a first microcircuit (246-A1) is directly connected with a common controller circuit (261) and the input conductor of each other microcircuit (246-A2...An) is connected with the data output conductor of the preceding microcircuit.

Claim 15

A key according to claim 12, characterised in that the microcircuits (246) are all alike and the output control circuit (292) of each microcircuit is settable to transmit the received serialised data with associated information to the input conductor (273) of the following microcircuit, and in that each microcircuit comprises setting mean (287, 290) to enable the storing of a predetermined number of items of information for the selection of a character in the associated display (231) and the simultaneous controlling of the output control circuit (292) to stop the trans­mission of the serialised data with associated information to the following microcircuit and then to condition the output control circuit to transmit unchanged the received serial data with associated information to the following microcircuit once the predetermined number of items of information has been stored.

Claim 16

A keyboard for a data entry system, comprising a plurality of keys (220), each with a symbol display member (231) having a set of electrically activatable terminals (232) for displaying a matrix of areas representative of an associated symbol, and a controlling circuit (261) for generating selection information for sequentially actuating the activatable terminals of the plurality of keys, characterised in that each display member (231) is driven by an associated driver microcircuit (246), the driver microcircuits are connected in series, and each driver micro­circuit comprises display control circuit means (289) connected with the terminals of the display member (231) for displaying the matrix of areas of the associated symbol; an input conductor (273) and an output conductor (274), the input conductor of the first microcircuit (246-A1) being connected to the controlling circuit (261) and the input conductor of each other driver microcircuit (246 A2...An) being connected to the data output conductor of the preceding driver microcircuit; each microcircuit further compris­ing an output control circuit (292) feeding the data output conductor, means (286) for storing a predetermined number of selection information for the selective actuation of all the areas of the associated display; and means (287, 290) conditioning the output control circuit (292) for causing the output control circuit not to feed the selection information to the following driver microcircuit until it has stored the said predetermined number of items of selection information.

Claim 17

A keyboard for a data entry system, comprising a plurality of keys (220), each with a symbol display member (231) having a set of electrically activatable terminals (232) for displaying a matrix of areas representative of an associated symbol, and a controlling circuit (261) for generating selection information for sequentially actuating the activatable terminals of the plurality of keys, characterised in that each display member (231) is driven by an associated driver microcircuit (246), the driver microcircuits are connected in series, and each driver micro­circuit comprises display control circuit means (289) connected with the terminals of the display member (231) for displaying the matrix of areas of the associated symbol; an input conductor (273) and an output conductor (274), the input conductor of the first microcircuit (246-A1) being connected to the controlling circuit (261) and the input conductor of each other driver microcircuit (246 A2...An) being connected to the data output conductor of the preceding driver microcircuit; each microcircuit further compris­ing an output control circuit (292) feeding the data output conductor, means (286) for storing a predetermined number of selection information for the selective actuation of all the areas of the associated display; and means (287, 290) conditioning the output control circuit (292) for causing the output control circuit not to feed the selection information to the following driver microcircuit until it has stored the said predetermined number of items of selection information.

Claim 18

A keyboard according to claim 14, characterised in that the selection information comprise a given number of pulses and each microcircuit (246) comprises timing and decoding means (288, 289) responsive to these pulses for the actuation of the display member (231).

Claim 19

A keyboard according to claim 15, characterised in that each driver microcircuit (246) comprises a memory (286) to store the display information for the character to be displayed, and a circuit (284) to derive from the input conductor (273) refresh information to be transmitted to the following microcircuit through the output control circuit (292) during the storing of the said predetermined number of items of selection information in the driver microcircuit.