GB2122787A

GB2122787A - Single handed keyboard

Info

Publication number: GB2122787A
Application number: GB08218881A
Authority: GB
Inventors: Ian Andrew Noel Litterick
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1982-06-30
Filing date: 1982-06-30
Publication date: 1984-01-18

Abstract

A keyboard for operation by a single human hand comprises a plurality of keys positioned so as to be within the normal ambit of digits of a human hand and such as to be substantially symmetrically disposed about a plane of symmetry running from the front to the back of the keyboard. The keyboard has a first mode of operation in which operation of each key causes the production of a respective electrical signal, and a second mode of operation, in which production of each respective electrical signal is caused by operation of the respective mirror image key of that which produces it in the first mode to enable the keyboard to be used by a right-handed or left-handed operator. Means are provided either in hardware or software for switching between the first and second modes of operation. A pair of interchangeable overlays or a single reversible overlay may be provided bearing indicia identifying the function of the keys in the two modes. <IMAGE>

Description

SPECIFICATION Single handed keyboard This invention relates to keyboards operable by a single human hand. Such keyboards are becoming increasingly common in applications such as computer input and word processing, where it is desired that a hand of the operator should be free whilst inputing data or the like. A single handed keyboard of this kind is described for example in my European Patent Application No. 81900304.7 (derived from published International Application No. PCT/GB81/00013).

Conventional single handed keyboards are manufactured for use either by the right or the left hand, and this means that in general a manufacturer must produce a second version if both right-handed and left-handed operation is desired. If a layout is optimised for operation by the right hand, it would be less convenient for operation by the right.

According to the present invention, there is provided a keyboard for operation by a single human hand, comprising a plurality of keys positioned so as to be within the normal ambit of digits of a human hand, and such as to be symmetrically disposed about a plane of symmetry running from front to back of the keyboard, means for producing an electrical signal on operation of the keys, the keyboard having a first mode of operation in which operation of each key causes the production of a respective electrical signal, and a second mode of operation, in which production of each respective electrical signal is caused by operation of the respective mirror image key of that which produces it in the first mode, means being provided for switching between the said first and second modes of operation.In this way, the allocation of symbols to the keys is changed, and the left-handed layout becomes the mirror image of the right-handed one. To change from right-handed to left-handed operation can thus be achieved by operation of a simple switch.

The keyboard may be arranged as a conventional matrix, using conventional technology for scanning the matrix, and interpreting the signals produced. For example, a microprocessor may be used to strobe signals in turn along the Y lines of an X-Y matrix. The processor will then read the output from the X lines, and according to the pattern which it reads, interpret which key is depressed. This is used as the key to decoding a table, where the relevant character codes are stored. Thus, a signal corresponding to the desired key is generated.

Shift, Control, and Numbers keys may also be provided. These may be scanned in the same way, and are used to set flags, which cause the characters output to be changed accordingly.

The means providing the first and second modes of operation may take a variety of forms.

For example, means may be provided for setting a flag, either by means of a physical electrical switch, or under software control, to cause a similar change to that caused by a Shift or Control key. Thus, on setting of the flag, a different "Wook- up" table will be used to decode the bit sequence read on the X lines of the matrix.

In an alternative embodiment, the same character table may be used, and means may be provided for strobing the Y lines in the opposite order in the left hand mode of operation to that used for the right hand mode.

A pair of interchangeable overlays may be provided, bearing indicia identifying the functions of the keys, one of the overlays being substantially in the mirror image of the other. Alternatively, a single reversible overlay may be provided, bearing on one side thereof indicia identifying the function of the keys in the first mode of operation, and on the reverse side thereof indicia identifying the function of the keys in the second mode of operation. A switch may be provided to switch between the modes on location of the appropriate overlay. Thus, a cut-out may be provided in the overlay (or, when two interchangeable overlays are used, in one of the overlays) whereby a mode switch is depressed by the overlay when right hand operation is desired.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic block diagram of the circuitry used in an embodiment of a keyboard according to the invention; Figure 2 is a schematic diagram of circuitry used for scanning the keyboard; and Figure 3 shows a possible arrangement of key layout for a keyboard according to the invention.

Referring to Figure 1, a keyboard arrangement is scanned as a conventional 7 x 7 matrix, by a keyboard encoder 2. A look up table is provided in read-only memory (ROM) 3, to generate desired characters on depression of the keys. The character signals generated are passed to a parallel-to-serial converter 4, and from there to a standard (RS-232C) interface, from where they may be input to any standard device in a conventional way.

Also incorporated within the keyboard are Mode, Control, Numbers, and Shift keys or switches 5, which feed switching circuits 6, so as to vary the characters generated at the output interface. In the embodiment shown these keys are separately hard-wired to switching circuits 6, but in a preferred embodiment, they may be simply scanned as part of the keyboard matrix, and the signal decoded to emulate in software the separate hardware switching circuits. This method has the advantage that these keys, as well as the character keys, may be switched on change of mode.

A suitable key layout is shown in Figure 3. In the arrangement shown, keys are arranged in three major columns for operation by the index, middle, and ring fingers respectively, each major column incorporating with in it two sub-column.

Shift, Control, and Capitals Keys are provided in a conventional way, so as to enable a variety of characters to be produced by each key.

The keyboard is symmetrical about the centre line A-A of the "middle finger" column. A reversible overlay has letter and other indicia on the side shown, and on the reverse side has the same indicia in their mirror image reversed positions. The keyboard encoder is arranged so as to generate the indicated letters under normal operation, in upper or lower case, depending on whether the SHIFT key is depressed or not, the "shift lock" mode (operated by the "CAPS" key) is in operation; operation of one of the keys of the three control columns simultaneously with the NOS key gives the corresponding symbol indicated to the upper left of each letter. The NOS mode may be locked by means of the NOS LOCK key. When the NOS mode is operative simultaneously operation of SHIFT with a key gives access to the symbols indicated to the upper right of each letter. Direct access to this mode is provided by the SHIFT NOS key.

In the embodiment shown, a switch is provided on the rear panel of the device, to enable switching between a first mode of operation, in which the keys function as just described and a second mode of operation, in which each key takes on the function of the respective mirror image key in the first mode.

The keyboard according to the invention may be incorporated in computing, typewriting, or data processing equipment or the like, or may be provided as a stand-alone unit for use with such equipment.

Claims

1. A keyboard for operation by a single human hand comprising a plurality of keys positioned so as to be within the normal ambit of digits of a human hand and such as to be substantially symmetrically disposed about a plane of symmetry running from the front to the back of the keyboard, means for producing an electrical signal on operation of the keys, the keyboard having a first mode of operation in which operation of each key causes the production of a respective electrical signal, and a second mode of operation, in which production of each respective electrical signal is caused by operation of the respective mirror image key of that which produces it in the first mode, means being provided for switching between said first and second modes of operation.

2. A keyboard as claimed in Claim 1, having a pair of interchangeable overlays bearing indicia identifying the functions of the keys, one overlay being substantially the mirror image of the other.

3. A keyboard as claimed in Claim 1, having a reversible overlay bearing on one side thereof indicia identifying the function of the keys in the first mode of operation and on the reverse side thereof indicia identifying the function of the keys in the second mode of operation.

4. A keyboard as claimed in Claim 2 or Claim 3 wherein the switching means comprises a mechanical switch arranged to be operated on location of the identifying overlay.

5. A single handed keyboard substantially as hereinbefore described with reference to and as illustrated by Figure 1, Figure 2, or Figure 3 of the accompanying drawings.