WO2006087724A2

WO2006087724A2 - Multilingual keyboard

Info

Publication number: WO2006087724A2
Application number: PCT/IL2006/000215
Authority: WO
Inventors: Daniel Bitran; Moshe Bitran
Original assignee: Daniel Bitran; Moshe Bitran
Priority date: 2005-02-21
Filing date: 2006-02-20
Publication date: 2006-08-24
Also published as: WO2006087724A3

Abstract

A system for loading data into an array of display circuits, each of which, is located on a key being part of an array of keys of an input device (see figure 2). The array comprises a power line and a common line for supplying power to all of the key displays; and a row circuit for serially transferring data to that row and for updating. Each key display circuit comprises an oscillator for timing the serial data transfer; a controller for controlling the access of the key display to its corresponding portion of the data and a memory for storing said corresponding portion. The circuits connected to a key are physically implemented on a special flexible printed circuit board placed under the keys above the rubber domes, The flexible printed circuit board placed under the keys has an appropriate cut patterns so as to allow free key movement and zebra connections between the lower part of the keys and the key displays.

Description

MULTILINGUAL KEYBOARD

Field of the Invention

The present invention relates to the field of kej^boards. More p articular Iy, the invention relates to a method and system for loading displays of different sets of characters on keys of a keyboard, such that each set corresponds to a desired language.

Background of the invention

Modern multinational companies and offices of today have a need to use more than one language, especially in countries that English is not an official language. Fortunately, many of the computer applications today are able to perform applications in multilingual environments. Nevertheless, a problem with the keyboard layout is apparent as a need arises for displaying multilingual characters. In some of the keyboards, the layout of each key consists of an English letter displayed next to another language letter, which is a sufficient solution for double language use, but not for more than two languages, due to the limited area of each key. Therefore, a solution is needed for multilingual environments that require tjφing in more than two languages.

Another problem is that standard kejHboards are restricted to a certain amount of keys, which is compatible for letter using languages. Other languages like Chinese and Japanese may need dozens of keys for symbolizing all the language characters.

For the sake of brevity, all reference to changes of letter systems in a keyboard layout, such as change from one language to another, or change from lower case to upper case letters, or change from one set of sjrmbols to another in the same language, or change from qwerty layout to dvorak layout, or change from letters to symbols, or any other change, are referred to as a change of language.

The basic keyboards that are used today are very popular due to their low price and their compatible human interface. The keyboard itself is a series of key controlling switches that connect row and column grid circuits, and a keyboard encoder, which monitors the state of these switches by discovering the path of current flow through them. The inner array of the keyboard consists of a matrix of row and column circuits that are located underneath the keys, whereas the columns circuits and rows circuits form break points, which are actually membrane switches under the keyboard keys. When a key is being pressed, a break point of a column conduction line and a row conduction line is being bridged, thereby allowing a tiny amount of current to flow through the explicit column conduction line and the explicit row conduction line. The encoder of the keyboard monitors the key matrix for signs of continuity at any point on the grid. When it finds a circuit that is closed (conductive), it compares the location of that circuit on the key matrix, by noting the location of the column conduction line and the location of the row conduction line, to the code map stored inside its memoiy. The code map, stored in the memory of the keyboard encoder, is basically a comparison chart for the processor for indicating the code representation of the row and column coordinates in the key matrix. Therefore, when a user changes a currently used language to a different selected language, the keyboard continues sending the same code representation for each key pressed as before the change, although the interpretation of the code by the computer differs, according to the selected language.

As explained above, it is apparent that a standard keyboard is capable of virtual typing in any language, as the keyboard sends the code identifying the pressed key, rather than the code identifying the letter inscribed on the key. The interpretation of the code, sent by the keyboard, to a displayed letter of the selected language is made by the computer itself. For example, the code sent by the keyboard to the computer for representing the uppercase "A" and the lowercase "a" will be the same code, although the computer may interpret the same code differently, depending on the predetermined requirements. Nevertheless, a problem arises of displaying, the computer interpretation of each key on the keyboard to the user, in different languages.

As stated before, many computer applications today are capable of performing applications in multilingual environments of more than two languages, while the problem lies within the keyboard layout. Some of the solutions used today involve switching kej^boards, which can be tiresome, or connecting more than one keyboard to a computer, which can be very confusing. Other solutions, such as masking of the kejώoard with different layouts for different languages have been found unpractical. All the above suggestions offer only a partial solution to a user wishing to use a minimal number of languages and symbols. One existing solution that is not restricted to a minimal number of languages is implementing a virtual keyboard on a display by using a touch screen, touch panels or similar devices. However, this solution lacks the tactile comfort of keyboards.

USP 4,551,717 discloses a system for a programmable keyboard for use on a terminal, where each key on the keyboard has an LCD that displays the indicated programmed function of the key. However, this patent does not disclose an efficient system for addressing the keys for the purpose of loading the bitmaps in each key, and requires a dedicated enable signal for each key.

It is an object of the present invention to provide a system which is capable of quickly loading a displayed pattern for each key in a keyboard. It is another object of the present invention to provide an inexpensive sjrstem, capable of efficiently loading a displayed pattern for each key in a keyboard.

It is still another object of the present invention to provide a system which is capable of quickly loading a displayed pattern for each key in a kejώoard without compromising the tactile comfort of kej^boards, and without burdening each key with many electrical connections.

It is still another object of the present invention to provide a system which is capable of loading an individual displaj^ed pattern for each key, even though all keys have the same kejr circuit.

It is still another object of the present invention to provide a system which is capable of dynamically loading the displays on keys and to inform the user which tjφe of chai-acters he is using.

It is still another object of the present invention to provide a system that can be manufactured in mass production, using automated assembly techniques.

Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention

The present invention relates to a system for loading data into an array of display circuits, each of which is located on a key being part of an array of keys of an input device, that comprises: (a) at least one power line, connected to a first contact of a power supply, for supplying power from said power supply, to all of said key displays; and (b) at least one line for connecting all of said key displays to a common connection being the second contact of said power supply; (c) at least one row circuit for serially transferring data to said row, for updating, whenever desired, each key display in said row. Each key display circuit comprises an oscillator for timing said serial data transfer, a controller for controlling the access of said key display to its corresponding portion of said data, a memory for storing said corresponding portion. Each key display circuit in each row is updated by accessing its corresponding portion in a different timing, according to its location within a row, and storing said corresponding portion in its memory.

Preferably, the system further comprises at least one column circuit for applying current to a selected column of key display circuits, to be updated, and for allowing key display circuits in said selected column to receive their corresponding portion of said data transferred by their corresponding row circuit(s), wherein the column circuit is used for determining which key is pressed.

Preferably, the row circuit is a group of daisy-chained circuits and each key receives the serial data from the preceding key, modifies the serial data and transfers the modified serial data to the next key, whereby the first key of a group receives the serial data from the keyboard encoder.

The serial data may comprise a start sequence and a multitude of bitmaps, each of which targeted to a key of said group, whereby each key copies the targeted bitmap. Preferably, the data is transferred concurrently to all rows.

Preferably, the system further comprises at least one row circuit for indicating a closed switch on the array of keys, such that the switch is external to, or inside the key. Preferably, the row circuit and the row data circuit are capable of indicating a closed switch on the array of keys, wherein the switch is inside the key.

The serial bitmap signal may be transferred in data blocks, wherein the data blocks start with a start bit.

Preferably, the display circuit is identical in all keys, without any programmed identity or address. The updating data may be transferred from, an external source or from an internal source. Preferably, the displays are updated from a memory of an encoder within the system.

Preferably, a zebra rod is placed between the key circuit and the flexible PCB at the bottom of the key to provide electrical connections between them.

The invention also relates to an input device that includes: a. an array of keys for inputting data; b. a system for loading data into an array of display circuits, each of which is located on a key of the array, the system comprises: cat least one power line, connected to a first contact of a power supply, for supplying power from the power supply, to all of the key displa3^s; d. at least one line for connecting all of the key displays to a common connection being the second contact of the power supply; and e. at least one row circuit for serially transferring data to the row, for updating, whenever desired, each key display in the row, wherein each key display circuit comprises an oscillator for timing the serial data transfer, a controller for controlling the access of the key display to its corresponding portion of the data, a memory for storing the corresponding portion and wherein each key display circuit in each row is updated by accessing its corresponding portion in a different timing, according to its location witliin a row, and storing the corresponding portion in its memory.

The invention further relates to a method for loading data into an array of display circuits, each of which is located on a key being part of an array of keys of an input device. At least one row circuit is provided for serially transferring data for updating each key display in that row, whenever desired. An oscillator for timing said serial data transfer, a controller for controlling the access of said key display to its corresponding portion of said data, and a memory for storing said corresponding portion are provided for each key display circuit. Key displays are allowed to receive their corresponding portion of said data transferred by their corresponding row circuit. Whenever desired, each key display is updated in a different timing according to its location within a row.

Brief Description of the Drawings

In the drawings:

Fig. 1 is a block diagram schematically illustrating a portion of the inside of a prior art mechanical keyboard;

- Fig. 2 illustrates a side view of a keyboard key in one of the embodiments of the invention;

- Fig. 3 is a block diagram schematically illustrating a portion of an embodiment of the invention;

Fig. 4 is a timing graph according to an embodiment of the invention.

- Fig. 5 is a block diagram generally illustrating the main blocks of a key circuit according to an embodiment of the invention;

- Fig. 6 illustrates a side view of a keyboard key according to another embodiment of the invention;

- Fig. 7 is a block diagram schematically illustrating a portion of another embodiment of the invention; - Fig. 8 is a block diagram schematically illustrating a portion of yet another embodiment of the invention;

Fig. 9 is a block diagram generally illustrating the main blocks of a key circuit according to another embodiment of the invention;

- Fig. 10 is a block diagram generally illustrating a portion of yet another embodiment of the invention;

- Fig. 11 is a timing diagram according to another embodiment of the invention;

- Fig. 12 is a timing diagram according to yet another embodiment of the invention; and

Fig. 13 is a block diagram generally illustrating the main blocks of a key circuit according to yet another embodiment of the invention.

Detailed Description of Preferred Embodiments

In a prior art mechanical keyboard there are many switches which are controlled by keys, however, for the sake of brevity, Fig. 1 and the following explanation deal with a portion of the

consisting of a small amount of switches. When a user presses a key in the keyboard, the key pressures the switch to connect and to switch into its closed (conductive) position, and when the user stops pressing the key, the key springs back, thereby releasing the pressure on the switch and causing the switch to disconnect and switch into its open (nonconductive) position. In Fig. 1 Keyboard Encoder (KE) 10 scans for closed switches by supplying a small amount of current through the column circuits (101, 102, 103, ...), one after another rapidty, and waiting to receive the current from one of the rows. For example, if switch 332 is closed because the user pressed the key above it, column 102 is shorted to row 230, thus when KE 10 supplies a current to column 102 it receives the flow of current from row 230. When KE 10 receives the flow of current from one of the rows it automatically notes the number of column and number of row that the current flows through. The row number and column number are compared to a chart that is pre-stored in the memory of KE 10 and a code symbolizing the pressed key is sent to the connecting computer via communication line 11, which connects between the keyboard and the computer, informing it which key has been pressed. KE 10 will continue sending a current through the columns one after another searching for closed switches.

Fig. 2 illustrates a side diagram of a key in the proposed keyboard, according to one of the embodiments. The plastic key 504, which is held in place by the keyboard upper cover 503 and above an elastic dome 506, comprises a display 501 which may be a small LCD or any other form of display, a small circuit 502 controlling the display 501, flexible wires 505 connected to display 501 and circuit 502 on one side and connected to flexible conductors located in a first flexible PCB 509 on the other side. The elastic dome 506 is located on top of a second flexible membrane switch PCB 507. The data comprising a letter or sign for display of a selected language, is referred to hereinafter as a bitmap. The bitmap designated for key 504 is sent through flexible PCB 509 and flexible wires

505 to circuit 502, which sorts the data received and loads the display 501 with the designated bitmap. Therefore, the user will be able to see on display 501 of each key in the keyboard the letter or symbol the key refers to. Upon pressing key 504 the elastic dome 506 flattens on flexible membrane switch PCB 507 switching the membrane switch 508 to its close position until the pressure on key 504 is lifted, and the elastic dome

506 springs back up switching switch 508 to its open position. When switch 508 is in its closed position, the corresponding column and row circuits are shorted, allowing current to flow from column to row causing the KE to identify the pressed key.

As may be understood by a person skilled in the art, the first flexible PCB 509 and second flexible membrane switch PCB 507 may be composed of a number of flexible layers. In addition, flexible PCB 509 connects to key 504 in a loose manner that allows the key to shift freely without degrading the tactile feeling of the key. Flexible wires 505 may be a "zebra" rod, which is a rod of elastic insulating material, comprising a large number of thin vertical conductors or conductive elastomers embedded within, where the conductors can be contacted at both sides of the rod. The zebra rod may be connected to the flexible PCB 509 with a plug 510 clamped to the bottom of the key.

Fig. 3 schematically illustrates an embodiment of the invention, showing a portion of the inside of the proposed keyboard while enhancing one of the switches. The embodiment of the invention is different from the prior art described in Fig. 1 in the additional memory block 20 with data line 21, key circuit 502, and the additional circuits 410, 411, 510, 511, 610 and 611. Circuit 410 is in fact a communication bus connected to all the key circuits in the row, therefore when a communication signal is transmitted by KE 10 over bus 410, all key circuits in the row connected to bus 410 may receive the data. Nevertheless, in an embodiment of the invention, each key circuit is configured to accept the communication from the bus only when receiving a current from its column circuit. Therefore in Fig. 3, circuit 502 receives the bitmap intended for ke}' 504, through bus 410 and circuit 411, only when a current is provided by column circuit 101 and circuit 111. Circuits 510 and 610 provide the Power (Vcc) and Ground (Grnd), by circuits 511 and 611 accordingly, to key circuit 502 as well as to all other keys.

As described before, in Fig. 3 communication line 11 connects the keyboard and the computer for transferring data, and can be used for transfer of all bitmaps of the selected language from computer to keyboard. Therefore, when a user requests the computer to change language, all the bitmaps of the requested language are transferred through line 11 from the computer to KE 10 where it transfers the data through communication lines 21 to Bitmap Memory (BM) 20 for data storage. While storing all the bitmaps in BM 20, KE 10 continues supplying current to the columns, one after another, for detecting closed switches as described before. In one of the embodiments, after storing all the bitmaps in BM 20, KE 10 loads from BM 20 a string of bitmaps for the keys in the row connected to bus 410, simultaneously with loading all the other strings to the other rows (not shown in the drawing). The loaded string, designated for bus 410, is transmitted on bus 410 in perfect timing with the current supplied to the columns. In other words, the data designated for display on key 504 is transmitted on bus 410 when a current is supplied on column 101, whereas each bitmap is transmitted for the designated key when a current is supplied to the column attached to that key.

It should be noted that all bitmaps may be loaded into the keys periodically in case one of the bitmaps dissolved due to power supply malfunctions.

In one of the embodiments each key circuit has its own oscillator for timing the data received instead of connecting another clock bus to all keys. The key circuit uses the oscillator for determining when to sample the data received, which is calculated to be at the middle of each bit.

In Fig. 4 a time table of one of the embodiments is shown for illustrating the bitmap load rate to each key. In one of the embodiments, the key display is a 16*12=192 dot matrix which means that each key has to be loaded with approximately 200 bits. Since the key circuit uses an internal oscillator, a lag in bitmap receiving time may occur when loading a full bitmap in one string. Therefore, each bitmap may be divided into packets with start bits and packets separating bits, so as to allow the key circuit to synchronize the oscillator every packet period. This permits a low precision oscillator to be used in the key circuit, as it is synchronized periodically. The figure illustrates that while current flows from the column circuit 111, data packets are being received from bus 411.

In one of the embodiments, as shown in Fig. 4, the bitmap of 200 bits is divided into twenty packets of ten bits each, where two predetermined start bits are added at the beginning of each packet and another bit is added at the end of the packet, totaling thirteen bits for each packet. In one of the embodiments the bit rate is calculated to be 2 microseconds for each bit (i.e. 500 kbps.). Therefore, the sending of a full bitmap may take 520 usec (2 usec * (20 blocks * (10+3) bits) = 520 usec). It should be noted that the switches of a standard prior art keyboard, as described above, are organized in eight rows and sixteen columns. Therefore, if the total scan time is 9.2 msec, each column is scanned for (9200:16=575) 575 usec. Therefore, it can be seen from the timing diagram in Fig. 4 and the calculations above that a hey may be fully loaded in less time than the column scan time. Moreover, the time needed to fully load the keyboard is 9.2 msec (16 columns * 575 usec), which is not noticeable by the user. Furthermore, as described above, each key will be periodically loaded, in packets, with the current bitmap, in case one of the bitmaps dissolved due to power supply malfunctions.

As may be understood by a person skilled in the art, the bitmap may consist of any number of bits, packets may consist of any number of bits, and any kind of start or end bits is possible according to the practical needs of the design.

Fig. 5 is a block diagram illustrating the key circuit 502 in one of the embodiments where Serial Bitmap Signal Decoder (SBSD) 551 receives the serial signal from circuit 411 only when a signal from circuit 111 is present. The SBSD 551 uses the key circuit oscillator 552 for receiving the incoming bitmap, which it transfers to the Bitmap Memory 553 and to the Display Drive Logic 556 through bus 554. The Display Drive Logic 556 can use the same key circuit oscillator 552 or another hey circuit oscillator 555 to load the bitmap into the Y drivers 557 and X drivers 558 which control the Display 501.

In one of the automatic assembly embodiments, with reference to Fig. 2, the key display together with key circuit, are inserted into the designated keyboard keys, where each key has the same key circuit. A zebra rod 505 is then inserted through the key shaft, as illustrated in Fig. 2. At this point, an upper cover of the keyboard case 503 is placed upside-down where all of the designated keys are inserted in the appropriate manner. Upon inserting all the keys, the first flexible PCB 509 is placed on the keys and each of the connection strips of the PCB 509 is inserted into the keys and contacted to the zebra rod 505 of the key with the aid of a plastic plug 510. A rubber dome plastic 506 is then placed on the keys. Then, another flexible membrane switch PCB 507 is placed before the bottom part of the keyboard case (not shown) and the whole assembly is held by means of screws (not shown).

Fig. 6 illustrates another embodiment similar to the embodiment of Fig. 2. Nevertheless, in Fig. 6 the two flexible PCBs are unified. The membrane switch 508 is part of the unified PCB 509 and clamped inside the key 504 above a hole in the clamping plug 510 and a hole in the rubber dome. Therefore, when the key 504 is pressed, the rubber dome flattens allowing the bulge 522 to pressure the membrane switch 508, which is now located inside key 504. In the described embodiment, flexible membrane 509, which may be composed of a number of flexible foils, is capable of transmitting the bitmap data to circuit 502 and detect when the key has been pressed. Fig. 7 is a block diagram describing the keyboard embodiment corresponding to the key embodiment described in Fig. 6, showing a portion of the inside of the proposed keyboard while enhancing one of the switches. Fig. 7 is different from Fig. 3 in the location of switch 311. In Fig. 7 the switch 311 is located inside the key and not under the key. Therefore, as shown in the drawing, wire 211 is extended into the key 504, where it connects to switch 311. As before switch 311 is capable of connecting wire 211 and wire 111 for signaling to KB 10 that the kejr is pressed.

Fig. 8 describes another embodiment corresponding to the key described in Fig. 6, where the switch is located inside the key similar to Fig. 7. However, in the proposed embodiment bus 410 is capable of transmitting the bitmap to the key and sensing when the key is pressed without the need for circuit 210, thus reducing the number of contacts to key 504. As described before, KE 10 sends through 410 bitmap data continuously to all keys of the row in periodic cycle. However, when the ke3_^ 504 is pressed and switch 311 is closed, circuit 101 is in fact connected to circuit 410 through circuits 111 and 411. In this embodiment circuit 101 has low impedance to the ground and circuit 410 has limited impedance in high logical state. When KE 10 detects that the high signal transmitted on bus 410 is low, it automatically notes the number of the column supplying the current and the number of bus for comparison to the chart, pre inserted in the memory of KE 10, and transmits the key code to the computer through communication line 11. After transmitting the code to the computer, KE 10 may transmit the same bitmap block again on bus 410, as it had not been received by the key circuit 502.

Fig. 9 is a block diagram illustrating the inside of a key circuit 502 illustrated in Fig. 8. When the key is pressed, switch 311 is closed thus connecting circuit 111, which has low impedance to the ground, and circuit 411 which has limited impedance in high logical state. As described before when KE 10 detects that the high state signal transmitted to circuit 411 is low, it automatically notes the number of the column supplying the current and the number of bus supplying circuit 411 for comparison to the pre inserted chart in the memory of KE 10, and transmits the key code to the computer through communication line 11. In other aspects, elements of Fig. 9 are similar to elements of Fig. 5 and functions as described above.

In one of the assembly embodiments where the two PCBs are unified, as described in Fig. 6, the key display 501 together with key circuit 502, are inserted into the designated keyboard keys, where each key has the same key circuit 502. A zebra rod 505 is then inserted through the key shaft, as illustrated in Fig. 6, and contacted with the display 501 and key circuit 502 in each key. At this point, an upper cover of the keyboard 503 is placed upside-down where all of the designated keys are inserted in the appropriate manner. Upon inserting all the keys, the flexible membrane board 509 is placed on the keys and each of the connection strips of the membrane is inserted into the keys and contacted to the zebra rod 505 of the key with the help of a plastic plug 510. A rubber dome plastic 506 is then placed on the keys after which the bottom part of the keyboard (not shown) is placed, and the whole assembly is held by means of screws (not shown).

Fig. 10 schematically illustrates another aspect of the invention, similar to the one described in Fig. 3. However, in this embodiment, data bus 410 is connected solely to key circuit 502. Data bus 410 transfers the bitmaps of all keys in the row from KE 10 to key circuit 502. At this point key circuit 502 copies the specific bitmap to key memory within (not shown), and sends the bitmaps on data bus 411 to the next key circuit (not shown). Every key in the row copies its specific bitmap and sends the bitmaps to the next key circuit until the last key in the row receives its bitmap. Therefore, instead of one data bus transferring all the data to the keys there are many daisy chained circuits, between the keys, which transfer the data from one key to another.

In Fig. H a time table of one of the embodiments is shown for illustrating the bitmap load rate to each key. In one of the embodiments, the key display is a 16*12=192 dot matrix which means that each key has to be loaded with approximately 200 bits. Therefore, if a row of a standard keyboard has 16 keys, the Serial Bitmap Signal (SBS) which stores the bitmaps of all the keys in the row will be approximately 16*200=3200 bits. The SBS is transmitted by KE 10 on bus 410 to key circuit 502. In one of the embodiments, the SBS includes a start sequence and an index number before the bitmaps. The index number indicates to the key circuit 502 which bitmap from the SBS it should read and copy. Therefore, when key circuit 502 receives the SBS, it automatically copies the bitmap referred to by the index, after which it increases the index number by one before transmitting the SBS to the next circuit. The next circuit performs the same operations as the first circuit and copies the bitmap referred by the new index after which it increases the index number by one and transmits the string further. This process continues until the last key circuit in the row receives its designated bitmap. As described above, although all key circuits may be identical, each key circuit loads its unique bitmap from the SBS, according to the index it receives.

In Fig. 12 another embodiment is illustrated where the SBS has a start sequence without the index number. Therefore when the key circuit receives the SBS, it automatically copies the first bitmap after the start sequence and deletes it from the SBS. The new SBS, excluding the copied bitmap, is then transmitted to the next key circuit. The process continues until the last key circuit receives the last SBS which has a start sequence and one last bitmap designated to that circuit. As explained before, although all key circuits are identical, each key circuit loads the first bitmap it receives from the SBS, which is the unique bitmap designated for that circuit.

The SBS sequence must be sent by the KE at each change of the keyboard layout but may also be sent periodically, to refresh the existing bitmaps. The start sequence, which may be a high auto-correlative sequence, enables the key circuits to recognize the beginning of an SBS sequence. The KE has multiple outputs to send SBS sequences to all kejr rows simultaneously.

Since the key circuit uses an internal oscillator, a deviation in bitmap receiving clock timing may occur when loading a full bitmap in one string. Therefore, each bitmap may be divided into packets with start bits and packets separating bits, so as to allow the key circuit to synchronize the oscillator every packet period. This permits a low precision oscillator to be used in the key circuit, as it is synchronized periodically.

Fig. 13 is a block diagram illustrating the Key Circuit 502 of Fig. 10, according to one of the embodiments, where Serial Bitmap Signal Decoder (SBSD) 551 receives the SBS from circuit 410 and resends it to circuit 411 after incrementing the index bits as, explained earlier in one of the embodiments or after deleting the first bitmap of the SBS according to a second embodiment. In other aspects, elements of Fig. 13 are similar to elements of Fig. 5 and function as described above. In one of the automatic assembly embodiments, the key display together with key circuit, are inserted into the designated keyboard keys, where each key has the same key circuit. A zebra rod 505 is then inserted through the key shaft, as illustrated in Fig. 2. At this point, an upper cover of the keyboard case 503 is placed upside-down where all of the designated kej^s are inserted in the appropriate manner. Upon inserting all the keys, the first flexible PCB 509 is placed on the keys and each of the connection strips of the PCB 509 is inserted into the keys and contacted to the zebra rod 505 of the key with the aid of a plug. A rubber dome 506 is then placed on the keys. Then the flexible membrane switch PCB 507 is placed before the bottom part of the keyboard case (not shown) and the whole assembly is held by means of screws (not shown).

For the sake of brevity all the descriptions of circuits and busses refer to each row of keys individually, nevertheless a person skilled in the art may be well aware that the circuits and busses may connect any group of keys.

As may be understood by a person skilled in the art the invention may relate to other embodiments besides computer keyboard, such as musical instruments or any other digitally controlled machine tools, or to avionic equipment control panels or anjr other device or equipment comprising key input devices.

In another embodiment, the data of key bitmaps for many languages or configurations may be located initially in a non-volatile memory inside the keyboard, without loading them from the computer. In this case, the computer can cause the keyboard to change the language or configuration by sending a short command.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried into practice with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention or exceeding the scope of the claims.

Claims

1. A system for loading data into an array of display circuits, each of which is located on a key being part of an array of keys of an input device, comprising: a. at least one power line, connected to a first contact of a power supply, for supplying power from said power supply, to all of said key displays; b. at least one line for connecting all of said key displays to a common connection being the second contact of said power supply; and c. at least one row circuit for serially transferring data to said row, for updating, whenever desired, each key display in said row, wherein each key display circuit comprises an oscillator for timing said serial data transfer, a controller for controlling the access of said key display to its corresponding portion of said data, a memory for storing said corresponding portion and wherein each key display circuit in each row is updated by accessing its corresponding portion in a different timing, according to its location within a row, and storing said corresponding portion in its memory.

2. A system according to claim 1, further comprising at least one column circuit for applying current to a selected column of key display circuits, to be updated, and for allowing key display circuits in said selected column to receive their corresponding portion of said data transferred by their corresponding row circuit(s), wherein said column circuit is used for determining which key is pressed.

3. A system according to claim 1, wherein the row circuit is a group of daisy-chained circuits and wherein each key receives the serial data from the preceding key, modifies said serial data and transfers the modified serial data to the next key, whereby the first key of a group receives said serial data from the keyboard encoder.

4. A system according to claim 3 wherein the serial data comprises a start sequence and a multitude of bitmaps, each of which targeted to a key of said group, whereby each key copies said targeted bitmap.

5. A system according to claim 1, in which the data is transferred concurrently to all rows.

6. A system according to claim 1, further comprising at least one row circuit for indicating a closed switch on the array of keys, wherein said switch is external to the key.

7. A sj^stem according to claim 2, in which the row circuit is capable of indicating a closed switch on the array of keys, wherein said switch is inside the key.

8. A system according to claim 1, in which the row data circuit is capable of indicating a closed switch on the array of keys, wherein said switch is inside the key.

9. A system according to claims 1 to 8, wherein the array of keys is the array of keys of a keyboard or of a keypad.

10. A system according to claim 1, wherein the data is a serial bitmap signal.

11. A system according to claim 10, wherein the serial bitmap signal is transferred in data blocks.

12. A system according to claim 11, wherein the data blocks start with a start bit.

13. A system according to claim 1, wherein said array of keys is a keyboard of a musical instrument.

14. A system according to claim 1, wherein the array of keys is an interface of an avionics control unit.

15. A system according to claim 1, wherein said array of keys is a control panel of a machine tool.

16. A sjrstem according to claim 1, wherein the display circuit is identical in all keys, without any programmed identity or address.

17. A system according to claim 1, wherein the updating data is transferred from an external source.

18. A system according to claim 1, wherein said updating data is transferred from an internal source.

19. A system according to claim 1, wherein the displays are updated from a memory of an encoder within the system.

20. A system according to claim 19, wherein the memory of the encoder is updated from a non volatile memory within the system.

21. A system according to claim 19, wherein the memory of the encoder is updated from an external entity.

22. A system according to claim 1, wherein the displays are capable of displaying patterns of letters or symbols of any language.

23. A system according to claim 1, wherein the displays are capable of displaying patterns of symbols of any kind including phonetic, numeric, or musical symbols.

24. A system according to claim 1 and 6, wherein the row circuit for serially transferring data is located on a flexible PCB, which is different than the row circuit, used for indicating a closed switch.

25. A sj^stem according to claim 1 and 7, wherein the row circuit for serially transferring data is located on the same flexible PCB of the row circuit, used for indicating a closed switch.

26. A system according to claim 25, wherein the membrane switch in the flexible PCB clamped under the key is pressed by a bulge located under it, on the bottom cover of the keyboard.

27. A system according to claims 24 to 26 wherein a zebra-rod is placed between the key circuit and the flexible PCB at the bottom of the key, so as to provide electrical connections between them.

28. A system, according to claim 27, wherein a strip of the flexible PCB which provides the connections to the key is held in place under said key and pressed against the zebra rod using a plastic plug clamped to the bottom of said key.

29. A system, according to any one of claims 24 to 28, where the keys and the array of keys is assembled automatically.

30. A system according to claim 3, in which the serial data includes an index determining the bitmap to be copied by the key circuit and in which the modification of the data includes changing said index, so that the following key circuit copies its targeted bitmap.

31. A system according to claim 3, in which the modification of the data includes removing the bitmap copied by the key circuit, so that the following key circuit copies the subsequent bitmap.

32. An input device that includes: a. an array of keys for inputting data; b. a system for loading data into an array of display circuits, each of which is located on a key of said array, said system comprises: cat least one power line, connected to a first contact of a power supply, for supplying power from said power supply, to all of said key displays; d. at least one line for connecting all of said key displays to a common connection being the second contact of said power supply; and e. at least one row circuit for serially transferring data to said row, for updating, whenever desired, each key display in said row. wherein each key display circuit comprises an oscillator for timing said serial data transfer, a controller for controlling the access of said key display to its corresponding portion of said data, a memory for storing said corresponding portion and wherein each key display circuit in each row is updated by accessing its corresponding portion in a different timing, according to its location within a row, and storing said corresponding portion in its memoiy.

33. A method for loading data into an array of display circuits, each of which is located on a key being part of an array of kej^s of an input device, comprising: a. providing at least one row circuit for serially transferring data for updating, whenever desired, each key display in said row; b. providing, for each key display circuit, an oscillator for timing said serial data transfer, a controller for controlling the access of said key display to its corresponding portion of said data, and a memory for storing said corresponding portion; c. allowing key

to receive their corresponding portion of said data transferred by their corresponding row circuit(s); and d. whenever desired, updating each key display in a different timing according to its location within a row.