GB2182179A - Whole-character keyboard - Google Patents

Abstract

The keyboard has a plurality of keys arranged in a matrix the centre part of the matrix being capable of identifying commonly used characters and other regions of the matrix being capable of identifying a relatively small number of less used characters selected (user-defined) from a large number of possible characters. Row and column integrated circuits C2 to C18 communicate with an integrated circuit C1. <IMAGE>

Description

SPECIFICATION Whole-character keyboard This invention relates to a whole-character keyboard for the entry of ideograms such as Chinesechar- acters.

Since these characters are required to appear on the screen of a computer, the problem of how to input Chinese characters has been tackled by special- ists all over the world. To adopt a Chinese characters coding technique is one of the common methods.

There exist various coding schemes including four- corner coding, three -corner coding, Romanized pronunciation 'pinyin' and basic strokes coding. However, the input methods based on these coding schemes rely on the employment of the 26 alphabetic and the 10 numeric keys of a standard English keyboard. Using these coding schemes, one needs at least on average of 2.7 keystrokes for the entry of a Chinese character. Using an English keyboard will, therefore, set a limit on the operational efficiency.

Since no one single method hasyetgained unanimous acceptance, operators sometimes have to memorize a few coding schemes in order to facilitate a smooth entry of Chinese characters. This complicates the problem of input of Chinese characters.

As regards membrane keyboards on the market, they require special input devices such as an electronic pen or an electrostatic stylus. These kind of membrane keyboards are relatively large in size, difficultto manufacture and high in cost.

An object of the present invention is to provide a whole-character membrane keyboard for the entry of ideograms which enables an operator to operate with both hands, which avoids the necessityforthe application of any coding schemes orthe memoriza tionofanycoding symbols and rules and which can be small in size and of low cost in manufacture.

The present invention therefor provides a keyboard having a plurality of keys arranged in a matrix the centre part of the matrix being capable of identifying commonly used characters and other regions of the matrix being capable of identifying a relatively small number of characters selected from a large number of possible characters.

The present invention also preferably provides a whole-character keyboard for the manual entry of ideograms comprising: a flexible character plate on which an array of key units are arranged in the form of a matrix, having a commonly-used-characters region and a user defined-characters region; a switch assembly disposed under said character plate comprising a plurality of parallel longitudinally disposed conductive strips and a plurality of parallel laterally disposed conductive strips occupying re spectively an area which is equivalent to the area occupied by said character plate;; a acircuit board disposed under said switch assembly comprising a plurality offirst integrated circuits and a second integrated circuit, said first in tegrated circuits being connected respectively to a prescribed number of said longitudinally and late rally disposed conductive strips forthetrans- mittanceofasignaltoandfromsaid membrane switch assembly and for receiving a recognition signal from said second integrated circuit, said second integrated circuit being connected to said first integrated circuits for sending out the recogniz- ing signal, for receiving the output signal from said first integrated circuits and converting said output signal to a zone position code.

Reference is now made to the accompanying drawings, wherein: Figure 1 shows a perspective view of an embodiment of a whole-character membrane keyboard, for the entry of Chinese characters, according to the present invention; Figure2 shows a block diagram of the circuitry of the embodiment; and Figure 3 shows a circuit diagram of the embodiment.

Referring to Figure 1, there is shown a wholecharacter keyboard 1 comprising a thin rectangular character plate 2 with each square unit on the character plate 2 representing a key unit 5. There are a total of 3360 key units 5 arranged on a 35 x 96 matrix. That is, there are 35 rows and 96 columns of key units. The character plate 2 has primarily Chinese characters imprinted thereon, is flexible and is made of plastics material.

The character plate 2 has a commonly-used Chinese characters region 3 being disposed at the centrethereofand user-defined characters in regions 4 being disposed at the sides thereof.

Chinese characters on the character plate 2 are grouped according to radicals. Chinese characters with a common radical are grouped into the same sub-region and are arranged in order according to the number of strokes ofthe remaining parts ofthe characters. Characters in the same region are packed closely together so as to restrict the sight area and hence to increase the speed of entry. Every subregion may be further distinguished by colours.

The user can write any desired characters or symbols on the key units 5 of the user-defined character region 4 by use of a pencil and erase it by means of an eraser when necessary. Character plate 2further comprises regions for seldomly-used characters, word phrases, characters of other languages and functions.

The character plate 2 overlays a membrane switch assembly 8 (Figure 3) with contacts 9 being arranged in the form of a matrix. Membrane switch assembly8 comprises a plurality of parallel longitudinally disposed conductive strips 10 and a plurality of parallel laterally disposed conductive strips 11. The spacing between each of the longitudinally disposed conductive strips 10 and the spacing between each ofthe laterally disposed conductive strips 11 is equivalent to the spacing of the key units 5. The laterally disposed conductive strips 11 are disposed perpendicularto and directly under the longitudinally disposed conductive strips 10. The longitudinally disposed conductive strips and the laterally disposed conductive strips 10, 11 occupy respectively an area which is equivalent to the area occupied by the character plate 2.The longitudinally disposed conductive strips and the laterally disposed conductive strips 10, 11 furthermore are supported and fixed into a prescribed position by their respective support means.

The longitudinally disposed conductive strips 10 of the membrane switch assembly Bare connected to five CMOS integrated circuits TYPE-U PD4051 ,with reference Nos. C14, Cis, C16, C17, C18 on the circuit board (as shown in the circuit of Figure 3) where each of the four integrated circuits UPD4051 (C1 5, C16, Cl 7, Cl B) is connected to eight ofthe longitudinally disposed conductive strips 10 and one integrated circuit UPD4051 (C14)isconnectedtotheremaining three longitudinally disposed conductive strips 10.

The laterally disposed conductive strips 11 are con- nected to twelve CMOS integrated circuits UPD4051 ; (C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13)on the circuit board, each of then being connected to eight of the laterally disposed conductive strips 11.

The circuit board further comprises a CMOS circuit C1 (UPD7507) which is connected to the abovementioned seventeen integrated circuits C2 to C1 8).

When a key unit 5 is pressed by the finger of an operator, a longitudinally disposed conductive strip 10 is pressed onto a corresponding laterally disposed conductive strip 11, thereby generating an input signal corresponding to the selected character imprinted on the key unit being pressed. The input signal is then transmitted to a corresponding integra- ted circuit C2 - C18.Atthe same time, integrated cir- cuit C1 is continuously sending recognition signals to each ofthe integrated circuits UPD4051. Whenever an integrated circuit C2 - C18 receives an input signal from the membrane switch assembly Sand a recognition signal from the integrated circuit C1 simultaneously, an output signal will be sent to the in tegrated circuit C1 where the outputsignal is converted into a zone position code which is then transmitted to the hostcomputerthrough a cable 6 and an RS232 interface 7.

Figure 2 shows a system diagram. The zone position codes are transmitted from the whole character membrane keyboard 1 to the central processing unit 15 ofthe host computerthrough the cable 6. The characters corresponding to the zone position codes are retrieved from a character library 16 and are eventually displayed on a display unit 18 through a display controller 17. The character library 16 is stored on a floppy disk and consists of a Chinese characters library having approximately 7,000 Chinese characters from the China's National Standard Character Set Gob231 2-80. The user can apply software program to store any desired Chinese character strings of unlimited length. Atotal of 128,000Chinese characters can be stored (with the installation of a 512KB RAM memory system). Retrieval is realized by way of one-touch entry.

The whole-character membrane keyboard adopts a compact keyboard with a width of 63 cm, a depth of 28 cm and a height of 2 cm. Spacing of the adjacent key units is 6 mm.

The operator can operate with both hands. With a light touch ofthe key units of the membrane keyboard, sound generating means 13 generates an audible signal informing the operator of an effective input.

Operation is easy and the system is practical. Entry of Chinese characters is direct with one touch per character. Applying entry of Chinese characters by strings, several characters can be entered by just one touch.

The whole-character membrane keyboard isa stand-alone component. It does not occupy any storage space of the host computer. It need not rely on any external power sources. With the presence of its built-in DCpowersupply unit 14,cable6and RS232 interface 7, it is operable as soon as it is connected to the host computer. Electronic components ofthe membrane keyboard are of high integration level CMOS microcontrollers and CMOS integrated circuits. The keyboard possesses all the advantages of space efficiency, lightweight, low powerconsumption and low cost in manufacture.

Claims (8)

1. Awhole-character keyboard for the manual entry of ideograms comprising: a flexible character plate on which an array of key units are arranged in the form of a matrix, having a commonly-used-characters region and a userdefined-characters region; A switch assembly disposed under said character plate comprising a plurality of parallel longitudinally disposed conductive strips and a plurality of parallel laterally disposed conductive strips occupying re spectively an area which is equivalentto the area occupied by said character plate;; a circuit board disposed under said switch assembly comprising a plurality offirst integrated circuits and a second integrated circuit, said first in tegrated circuits being connected respectively to a prescribed number of said longitudinally and laterally disposed conductive strips for the tra nsmittance of a signal to and from said membrane switch assembly and for receiving a recognition signal from said second integrated circuit, said second integrated circuit being connected to said first integrated circuits for sending outthe recognizing signal, for receiving the output signal from said first integrated circuits and converting said output signal to a zone position code.

2. Awhole-character keyboard as claimed in Claim 1 including a sound generating meansconnec- ted to said second integrated circuit for the gener- ation of an audible signal in response to each effective switch contact.

3. Awhole-character keyboard as claimed in Claim 1 orClaim 2 including a DC powersupplyunit being disposed inside the membrane keyboard for the supply of direct current.

4. Awhole-character keyboard as claimed in any one of Claims 1 to 3 including a cable and an interface being connected to said first integrated circuitforthe transmittance of said zone position code to a host computer by means of a standard digitally coded signal.

5. Awhole-character keyboard as claimed in Claim 4wherein the character plate has characters of foreign languages and notations offunctions imprin- ted thereon, and in which the user may furtherwrite any desired characters or symbols on said user defined characters region by means of a pencil and erase them by means of an eraserwhenever necessary the characters being accessible from a large store of characters stored in the host computer.

6. Awhole-character keyboard as claimed in Claim 1 forthe entry of Chinese characters by hand, wherein each key unit is 6x6 mm in diameter.

7. Awhole-character keyboard as claimed in any one of Claims 1 to 6 in which the first integrated cir cuitisoftype UPD4051 and the second isoftype UPD7507.

8. Awhole-character keyboard substantially as described with reference to the accompanying drawings.