GB2429618A

GB2429618A - Providing mouse button functions for a touch panel having both pointer and keyboard modes

Info

Publication number: GB2429618A
Application number: GB0616142A
Authority: GB
Inventors: William G Saich
Original assignee: VOLAMP Ltd
Current assignee: VOLAMP Ltd
Priority date: 2005-08-12
Filing date: 2006-08-14
Publication date: 2007-02-28
Also published as: GB0516584D0; GB0616142D0

Abstract

A user interface for a computer having a central processing unit and a monitor/visual display unit (4, fig 2) has a touch panel 3 separate from the display 4, the touch panel serving both as a keyboard 7 and as a pointer control device for a cursor displayed on the display 4. The touch panel is arranged to display or have printed a pattern of keys for a keyboard of a selected form, x and y co-ordinates of a position on the panel touched by a users finger or a pointer are identified as a particular key by a code converter (16, fig 2). The user may switch between a keyboard mode and a pointer mode in which a pointer control region 8 controls a cursor displayed on display 4, points on the pointer control region mapping to display 4. Many touch panels cannot accurately report simultaneous touches at different points on the panel, so one embodiment has buttons 11 or keys 14 located outside the pointer control region 8 that function as mouse buttons in the pointer mode; another embodiment interprets a sharp tap on the touch screen 4 in the pointer mode as operation of a mouse button at the tapped position. Keystroke orders in the keyboard mode are given to allow shifted keys or break codes to be input.

Description

1 2429618 USER iNTERFACE FOR A COMPIJTER This invention relates to user

interfaces for computers.

Examples of such interfaces include keyboards and computer mouses.

Conventional keyboards for computers are widely available and inexpensive.

They may be provided as stand-alone articles with some form of wireless or infrared connection with the central processing unit of a computer. They may be provided with a cable provided with a standard PS2, USB or other serial connector. They may be incorporated into the computer, for example in a laptop or notebook computer. WhiLe conventional standard keyboards with their alpha numeric keys and conventional function control keys are widely available and inexpensive, unconventional or special keyboards, for example for a language that does not employ conventional Latin characters or where only a small number of special function keys are required, are less readily available and are relatively more expensive.

Pointing controls in the form of the conventional computer mouse are also widely available and come in a number of different forms. Most computer mouses have a roller ball on the underside and one or two control buttons on the top and will either be connected to the central processing unit of the computer by a cable and PS2, USB or other serial connector or by an infrared connection.

Sometimes the pointer control is built into the keyboard. A typical laptop has three touch pads thereon, two of which correspond to the left and right mouse buttons of a conventional mouse, and movement of a finger across the third touch pad providing incremental control of a mouse cursor displayed on a visual display unit of the computer in substantially the same fashion that movement of a standard mouse roller ball provides such incremental control from wherever the cursor happens to be at the time the mouse is operated. Such touch pads are not easy to control and are not popular with users but are the best compromise currently available for laptop computers. In computers designed for military or industrial use a roller ball is commonly provided alongside the keyboard on the same unit whether provided as a separate unit coupled to the central processing unit by a cable or built into a laptop or similar device. The roller ball serves all the same functions as the roller ball on the underside of a conventional computer mouse. Separate left and right mouse buttons will also be provided adjacent the roller ball.

Because of the unnatural feel and difficulty of use of the conventional three panel touch pads on a laptop, many laptop users dispense with this control and simply plug a conventional mouse into their laptop even though this means that they must carry the mouse as well as their laptop, thereby reducing the advantages of portability possessed by a laptop.

All conventional keyboards whether provided as a separate unit from the central processing unit or combined with it as a laptop suffer the disadvantage that they include mechanically moveable parts. The inherent problems of mechanical parts are exacerbated by the fact that the laptop is exposed to dirt, dust and foreign matter such as biscuit crumbs, spilled coffee, etc. Touch screen technology is now well understood and used for a variety of uses, as for example in Stock Exchange or similar trading where touching parts of the visual display screen may effect electronic trading of financial instruments by controlling a computer or its software.

Previous attempts to provide a standard keyboard and/or mouse using conventional touch screen technology have not proved successful.

Thus, L G Electronics Inc. in EP 0725331 propose a touch panel which has three modes of operation, namely as a virtual keyboard, as a virtual mouse and as an extension of the visual display unit. In the keyboard mode a keyboard layout is displayed on the touch panel by use of a liquid crystal display and an infrared detection system is used for detecting the position on the touch screen in terms of its x and y co-ordinates which are touched, this being interpreted as operation of a particular key displayed on the virtual keyboard. In the mouse mode, in place of a keyboard, the liquid crystal display displays a conventional mouse with the conventional mouse buttons on the touch screen and the user must "pick up" this virtual mouse by touching it and then moving it across the screen in a continuous touching motion to provide corresponding incremental movement of a mouse cursor on the associated visual display unit. Touching the two mouse buttons displayed on the virtual mouse is interpreted by the system as the same operation as clicking a conventional mouse button on a conventional mouse, the position touched on the screen being interpreted as touching or clicking of the mouse button.

This system does not work at all satisfactorily because conventional touch screens are not readily capable of distinguishing positions when two or more positions are operated at the same time, which is something that would be unavoidable in operation of the virtual mouse of EP 072533 un the same way as a conventional mouse. As a consequence, to the best of Applicant's knowledge, no practical device employing the teaching of EP 0725331 has ever been provided commercially.

The present invention seeks to overcome the problems inherent in the disclosure of EP 0725331 and to provide a combined keyboard and pointing control device, which not only may be used in normal conditions, but which may be adapted for use in conditions where it may be exposed to dirt, dust or other foreign matter, for example in military use or in the construction and mining industries, or for use in circumstances in which surfaces of the user interface need to be cleaned, as for example in hospital use to avoid cross-infection between patients seen by the same consultant or in the processing of pharmaceuticals or other chemicals.

In accordance with a first aspect of the present invention, there is provided a user interface for a computer having a central processing unit and a monitor/visual display unit, the interface comprising: a touch panel separate from said monitor/visual display unit and adapted to serve both as a keyboard for controlling the computer and/or inputting data thereto and as a pointer controL device for a cursor displayed on the monitor/visual display unit; the touch panel being adapted to display a pattern of keys thereon for a keyboard of a selected form; position detection means associated with the touch panel and adapted to detect a position on the panel touched by a finger of a user or by a pointer in terms of x and y co-ordinates of that position; code converter means responsive to the position detection means to interpret the x and y coordinates of a position so touched as a detected key operated and to provide a keyboard output signal for the central processing unit of the computer corresponding to the key so detected; and means for switching between a keyboard mode in which the touch panel operates as a keyboard as defined above, and a pointer mode in which a pointer control region of the touch panel serves as a pointer control for a cursor displayed on a visual display unit of the computer, points on the visual display unit and on the pointer control region mapping to each other; the code converter means being responsive to the position detection means in the pointer mode of the touch panel to provide a signal for the central processing unit of the computer to control its monitor/visual display unit to display a cursor at the position on that monitor/visual display unit that corresponds to the touched position on the touch panel detected by the position detection means; and the user interface further including one or more keys located at positions outside the pointer control region and adapted to serve the same function as mouse button(s) of a conventional mouse when operated in the pointer mode of the touch panel.

These mouse button keys may be provided as separate buttons on the user interface alongside a mode control switch or button, or one or more of these switches/buttons may be effectively provided as keys displayed on the touch screen in a portion thereof separate from the region of the touch screen that maps to the visual display unit.

In a second and alternative aspect of this Invention, there is provided: a user interface for a computer having a central processing unit and a monitor/visual display unit, the interface comprising: a touch panel separate from said monitor/visual display unit and adapted to serve both as a keyboard for controlling the computer and/or inputting data thereto and as a pointer control device for a cursor displayed on the monitor/visual display unit; the touch panel being adapted to display a pattern of keys thereon for a keyboard of a selected form; position detection means associated with the touch panel and adapted to detect a position on the panel touched by a finger of a user or by a pointer in terms of x andy co-ordinates of that position; code converter means responsive to the position detection means to interpret the x and y coordinates of a position so touched as a detected key operated and to provide a keyboard output signal for the central processing unit of the computer corresponding to the key so detected; and means for switching between a keyboard mode in which the touch panel operates as a keyboard as defined above, and a pointer mode in which a pointer control region of the touch panel serves as a pointer control for a cursor displayed on a visual display unIt of the computer, points on the visual display unit and on the pointer control region mapping to each other; the code converter means being responsive to the position detection means in the pointer mode of the touch panel to provide a signal for the central processing unit of the computer to control its monitor/visual display unit to display a cursor at the position on that monitor/visual display unit that corresponds to the touched position on the touch panel detected by the position detection means; and the touch screen being adapted to recognise a sharp tap thereon by a User when in said pointer mode, and to interpret such tap as operation of a mouse button of a conventional mouse pointing to the position on said monitor/visual display unit to which the tapped position on said touch screen maps.

Position detection may be detected by infrared or by resistive or capacitive changes associated with touching of the screen. All three of these technologies have previously been employed for touch screens and can be applied with little or no change to the present invention.

Because the touch screen may be provided as a solid wipe clean element on its outer side, the whole keyboard/pointer control unit may be completely sealed preventing ingress of dirt, dust or other foreign matter and allowing its whole external surface to be wiped clean.

The invention is hereinafter more particularly described with reference to the accompanying drawings, in which:-.

Fig. I schematically illustrates the face/top panel of an embodiment of user interface for a computer constructed according to the present invention; Fig. 2 is a schematic circuit diagram of a computer system employing a user interface in accordance with the present invention; and Fig. 3 is a scrap view illustrating a variation of the system of Fig. 2.

Top panel 1 of user interface 2 includes a touch panel 3 which is adapted to serve both as a keyboard and as a pointer control for a cursor displayed on a visual display unit 4 of a computer 5 comprising a central processing unit 6, the visual display unit 4, user interface 2 and any other peripheral device. Touch panel 3 defines a keyboard area 7 and a pointer control area 8. These areas need not coincide though, to make best use of the area of the touch panel, they preferably substantially overlap. In a preferred arrangement, substantially the entire area of the touch panel that is visible serves as the pointer control area 8 while the keyboard area 7 comprises part only of the touch panel, in part because of the geometric arrangement of the keys. Suitably the keys 9 displayed in the keyboard area are in a conventional pattern with which a user is likely to be familiar from other keyboards.

For compactness, laptops commonly employ fewer keys than a conventional full PS2 keyboard, with the right hand numeric portion of the full PS2 keyboard often being omitted. Any of these keyboard variations may be employed in practical arrangements of the system described herein. The touch panel, at least in the keyboard area may be transparent so that a pattern of keys 9 may be provided as a printed underlay beneath the transparent area of the touch panel and visible therethrough. Alternatively, the pattern of keys 9 may be printed on the top or undersurface of the touch panel itself, in a further alternative, the pattern of keys 9 may be displayed through a transparent touch panel by providing a liquid crystal display 10 immediately beneath the touch panel, the pattern of keys 9 being displayed on the liquid crystal display 10 either whenever the user interface is in use or only when the user interface is operating in its keyboard mode.

In order to change the user interface 2 from its keyboard mode to its pointer control mode and vice-versa, one or more switches and buttons 11 are suitably provided alongside touch panel 3, together with LED or other indicators 12, which may indicate that the user interface is "on" and which mode is currently in operation.

In an alternative arrangement, a portion 13 of the touch panel 3 outside both the keyboard area 7 and the pointer control area 8 may be provided with one or more keys 14, in a manner similar to the display of the pattern of keys 9, the one or more keys 14 serving the same function as the one or more switches or buttons 11.

Touch panel 3 may operate with any of the conventional technologies for touch panels. Thus, the touch panel may be essentially resistive, the resistance of a material used on the surface of the touch panel changing when it is subject to pressure, for example when touched by the user's finger or by a pointer or stylus. In an alternative capacitive technology, an array of capacitive elements is provided in close association with a surface of the touch panel so that when a user's finger, or a pointer or stylus is brought close to a capacitive element, this causes the permitivity of an electrolyte to change slightly.

Scanning technologies may also be used in other alternative touch screens.

In these systems a beam of energy, which may be electromagnetic radiation at radio or infrared frequencies or may be a sonic signal, is used to scan the surface of the panel and a transducer is used to detect any obstacle such as the finger of a user, a pointer or stylus in the path of the beam.

The present invention is adaptable to any of these technologies.

In a typical arrangement (Fig. 2), the touch panel, whatever its technology, will be provided with or incorporate position detection means 15 adapted to determine x and y co-ordinates for a position touched and a code converter means 16 adapted to interpret the position so touched depending upon the functional mode of the touch screen at the time, and to provide a corresponding output signal.

Thus, when the touch screen is operating in its keyboard mode, the code converter 16 is responsive to the x and y co-ordinates determined by the position detection means 15 to interpret these as operation of a key defined by those co- ordinates and the code converter means provides a corresponding keyboard output signal to a keyboard output 17, the signal corresponding to the detected key.

Keyboard functionality is performed in accordance with the PS2 standard for keyboards and the keyboard output signal provided by the code converter means corresponds in all respects with the signal that would be produced by a normal electromechanical keyboard. However, touch screens cannot accurately report simultaneous touches at different points on the screen. This means that the keyboard cannot be operated satisfactorily where two keys are required to be pressed at once.

Thus, the use of key modifiers (namely "shift", "control" and "alt") - for example to get capital S by operating the "shift" and "s" keys - cannot be achieved with a keyboard as described herein in quite the same way as with a conventional keyboard, but apart from this minor variation in operation required when operating the keyboard, substantially all other keyboard functionality is possible. On a traditional electromechanical keyboard, in order to select capital S. the user will have to perform the four operations below * press "shift" * press "s" * release "s" * release "shift" In operation of the present keyboard the user must follow the following sequence of operations to produce the same result: * press "shift" * release "shift" * press "s" * release "s" Such a sequence of operations by the user may still result in the same sequence of signals being sent by the keyboard output 17 to the central processing unit 6 of the computer 5 if the code converter 16 buffers break codes for the key modifier keys. An example is given below for the sequence "control-shift-k." * 9 Using a conventional keyboard, the sequence of user operations and signals sent would be as follows: * user presses "control" keyboard sends make code for control * user presses "shift" * keyboard sends make code for shfl * user presses "k" * keyboard sends make code for k * user releases "k" * keyboard sends break code fork * user releases "shift" * keyboard sends break code for sh * user releases "control" * keyboard sends break code for control Using the present keyboard, the following sequence occurs: * user presses "control" * keyboard sends make code for control * user releases "control" * user presses "shift" * keyboard sends make code for shift * user releases "shift" * user presses "k" * keyboard sends make code for k * user releases "k" * keyboard sends break control for k * keyboard sends break code for sh/i * keyboard sends break code for control As can readily be seen, the same sequence of signals is actually sent even though the operator's key presses are slightly different, each press having to be released before the next is made.

In its pointer mode, the user interface 2 generates pointer control signals that are delivered by code converter 16 to pointer output 18 on the basis of x and y co- ordinates determined by position detection means 15.

A conventional computer mouse detects only relative movement. In other words, the resultant movement of a cursor is dependent on the starting position of the cursor, but independent of the absolute starting position from which the mouse is operated. The PS2 mouse standard reflects this incremental mouse operation.

In the present system there is a direct mapping between positions on the touch screen for the pointer control and positions on the monitor/visual display unit 4 of computer 5. This means that, following initial calibration, simply touching the touch panel in its pointer mode will result in the cursor instantly appearing at the corresponding position on the monitor/visual display unit 4 and continued movement of a finger across the touch screen from its initial touch position to a final touch position will result in a corresponding absolute movement of the cursor in the monitor/visual display unit. Thus, the pointer control adopted in the present system is an absolute control rather than an incremental control. In practice a user very quickly finds the position they want simply by placing their finger in approximately the right position on the touch screen and then moving it as necessary. The two mouse buttons conventional in an IBM- compatible computer system are here shown separately from the pointer control region 8 of the touch screen. They may either be provided as respective left and right mouse buttons in the buttons 11 or they may be provided as keys 14 displayed on a portion 13 of touch panel 3 outside the keyboard area 7 and the pointer control area 8. In either event, the equivalent control using this system to that for a conventional mouse requires two-handed operation with one hand providing the finger (or holding the pointer or stylus) that touches the screen and the other hand operating the corresponding switches or buttons 11 or keys 14.

Otherwise, the control provided by the pointer may be exactly the same as for a conventional mouse with the distinction, as noted above, that in the present system because of the mapping between pointer control area 8 of the touch screen 3 and the visual display unit of the computer, the user has absolute positioning rather than relative positioning of the cursor. Particularly in a military context, absolute positioning may result in faster operation, which is a significant advantage in

weapons control under battlefield conditions.

In some circumstances a third mouse button may be useful. It may be given a specific function, such as "Delete ", or it may be programmable by the User.

The mouse button function may also be provided in another fashion, namely by the touch screen interpreting a sharp tap on the screen as operation of the or a mouse button.

We have found a way of achieving absolute positioning using the relative movement PS2 mouse standard for communicating between the user interface and the central processing unit 6. In our arrangement, the moment the user touches the screen to begin a mouse movement a fast stream of movement commands is sent to pointer output 18 simply as a consequence of the screen being touched, wherever it is touched within the pointer control area 8, this fast stream of commands having the effect of sending the mouse cursor to the position on the monitor/visual display unit that corresponds to the x y co-ordinate origin on the pointer control area 8. The actual position on the pointer control area 8 of the touch panel 3 that is touched is then detected by the position detection means 15 as a position relative to the origin on pointer control area 8, and the conventional PS2 mouse standard movement packets are sent as if the pointer had been moved from the origin to the position actually touched by the user on the screen.

Interface 2 may include a speaker or buzzer as indicated at 19 providing an audible indication of a key being "pressed" by touching the corresponding position on the keyboard area 7. Change of mode from keyboard mode to pointer control mode and vice-versa may also be indicated by an audible signal which may differ depending on which mode is being made operational.

The arrangement described herein has the considerable advantage that no special drivers or software are required to be installed on the computer in order to make use of user interface 2 as central processing unit 6 simply sees the user interface 2 as if it were a conventional keyboard and a conventional mouse and the respective keyboard output 17 and pointer output 18 may be provided with conventional PS2 connectors adapted respectively for connection with respective PS2 keyboard inputs and mouse input on a central processing unit. In an alternative arrangement, the user interface may operate to the USB standard rather than the PS2 standard. Again no special software drivers on the host computer are required as the signals produced may be exactly the same as those that would be produced by a USB keyboard and a USB mouse. A single USB slot may be employed on the central processing unit by including a standard USB hub 20 within the user interface, the USB hub taking both the keyboard output 17 and the pointer output 18 as separate inputs (see scrap view of Fig. 3).

The system is particularly adaptable for use with less conventional keyboard layouts. Examples would be adaptation of a keyboard for languages that do not employ the standard Latin alphabet or where particular keys are to serve a particular function, as for example in a video editing system where function key "F 1" may be labelled "play". Another example would be a special touch panel keyboard provided in a shop window where some or all of the keys may be unconventional. One example would be the window of a Real Estate Agency in which a computer system is used to display property for sale or rent in which the keys are labelled with different types of property or different price bands and the pointer control is used to select between parts of what is then displayed on a computer screen within the shop visible through the window.

In some computer systems, dragging the mouse into the corner of the screen is used as a method for triggering particular actions. Initial movement of the mouse into the corner as a means of calibration could theoretically lead to false triggering in such systems but this may be readily avoided by the calibration point chosen being offset from the "hot corner", perhaps by a set distance in the x direction.

A touch screen is inherently thin. Accordingly, adoption of a user interface of the kind described hereinabove in a laptop in place of a conventional electromechanical keyboard has the merit that it enables the laptop to be thinner and possess less weight. Additionally, the user interface described hereinabove provides all the utility of a conventional mouse (with the added advantage of absolute rather than relative pointer positioning) without the need for the ancillazy small mouse pads currently common in laptops which users find difficult to operate.

In general the touch screen may have lower power requirements than a conventional keyboard and mouse. Modem laptop screens (visual display units) also have low power requirements. As a consequence, it is possible to fully seal a laptop utilising an interface as described above, so that the only openings are those for a power supply and for coupling external ancillary equipment via serial, parallel or USB ports and card reader slots, and none of these openings need provide any route to the interior space within the laptop casings. The resultant laptop may thus be usable in hostile (dirt, dust, moisture, chemical or biological exposure) conditions. Such laptops are especially useful for medical use, because the entire surface of the laptop can be disinfected between patients when used, for example, by a Consultant making his rounds with the laptop, thereby avoiding risks of cross- infection.

Claims

Claims 1. A user interface for a computer having a central processing unit

and a monitor/visual display unit, the interface comprising: a touch panel separate from said monitor/visual display unit and adapted to serve both as a keyboard for controlling the computer and/or inputting data thereto and as a pointer control device for a cursor displayed on the monitor/visual display unit; the touch panel being adapted to display a pattern of keys thereon for a keyboard of a selected form; position detection means associated with the touch panel and adapted to detect a position on the panel touched by a finger of a user or by a pointer in terms of x and y co-ordinates of that position; code converter means responsive to the position detection means to interpret the x and y coordinates of a position so touched as a detected key operated and to provide a keyboard output signal for the central processing unit of the computer corresponding to the key so detected; and means for switching between a keyboard mode in which the touch panel operates as a keyboard as defined above, and a pointer mode in which a pointer control region of the touch panel serves as a pointer control for a cursor displayed on a visual display unit of the computer, points on the visual display unit and on the pointer control region mapping to each other; the code converter means being responsive to the position detection means in the pointer mode of the touch panel to provide a signal for the central processing unit of the computer to control its monitor/visual display unit to display a cursor at the position on that monitor/visual display unit that corresponds to the touched position on the touch panel detected by the position detection means; and the user interface further including one or more keys located at positions outside the pointer control region and adapted to serve the same function as mouse button(s) of a conventional mouse when operated in the pointer mode of the touch panel.
2. An interface according to Claim I, wherein the mouse button key(s) is(are) provided as separate button(s) on the user interface, and the means for switching between a keyboard mode and a pointer mode comprises at least one mode control switch or button provided alongside said mouse button key(s).
3. An interface according to Claim 1, wherein the mouse button key(s) is(are) displayed on the touch screen in a portion thereof separate from the region of the touch screen that maps to the visual display unit.
4. An interface according to any preceding Claim, wherein, in addition to one or more mouse button keys serving the function of conventional mouse button(s), an additional mouse button key is provided, serving a dedicated function.
5. An interface according to any preceding Claim, wherein, in addition to one or more mouse button keys serving the function of conventional mouse button(s), an additional mouse button key is provided, the function attributed to said additional mouse button key being User programmable.
6. A user interface for a computer having a central processing unit and a monitor/visual display unit, the interface comprising: a touch panel separate from said monitor/visual display unit and adapted to serve both as a keyboard for controlling the computer and/or inputting data thereto and as a pointer control device for a cursor displayed on the monitor/visual display unit; the touch panel being adapted to display a pattern of keys thereon for a keyboard of a selected form; position detection means associated with the touch panel and adapted to detect a position on the panel touched by a finger of a user or by a pointer in terms of x and y co-ordinates of that position; code converter means responsive to the position detection means to interpret the x and y coordinates of a position so touched as a detected key operated and to provide a keyboard output signal for the central processing unit of the computer corresponding to the key so detected; and means for switching between a keyboard mode in which the touch panel operates as a keyboard as defined above, and a pointer mode in which a pointer control region of the touch panel serves as a pointer control for a cursor displayed on a visual display unit of the computer, points on the visual display unit and on the pointer control region mapping to each other; the code converter means being responsive to the position detection means in the pointer mode of the touch panel to provide a signal for the central processing unit of the computer to control its monitor/visual display unit to display a cursor at the position on that monitor/visual display unit that corresponds to the touched position on the touch panel detected by the position detection means; and the touch screen being adapted to recognise a sharp tap thereon by a User when in said pointer mode, and to interpret such tap as operation of a mouse button of a conventional mouse pointing to the position on said monitorMsual display unit to which the tapped position on said touch screen maps.
7. An interface according to any preceding Claim, wherein the position detection means comprises a scanning system adapted to scan the area of the touch screen with a beam of electromagnetic radiation at infra-red or radio frequency or a sonic beam, and a transducer adapted to detect interruption of said beam by an obstacle.
8. An interface according to any of Claims I to 6, wherein the position detection means comprise sensors for resistive changes associated with touching of the screen.
9. An interface according to any of Claims I to 6, wherein the position detection means comprise sensors for capacitive changes associated with touching of the screen.
10. An interface according to any preceding Claim, wherein the touch panel has a solid wipe clean element on its outer side.
ii. An interface according to any preceding Claim, completely sealed to prevent ingress of dirt, dust or other foreign matter and allowing its whole external surface to be wiped clean.
12. An interface according to any preceding Claim, wherein substantially the entire area of the touch panel that is visible serves as the pointer control area, and wherein the touch panel is adapted to display said pattern of keys in a keyboard area that comprises part only of the touch panel.
13. An interface according to Claim 12, wherein the touch panel is transparent at least in the keyboard area, the pattern of keys being defined visually as a printed underlay beneath the transparent area of the touch panel and visible therethrough.
14. An interface according to Claim 12, wherein the pattern of keys is defined visually as printing on the top or undersurface of the touch panel.
15. An interface according to Claim 12, wherein the touch panel is transparent at least in the keyboard area, the pattern of keys being defined visually by a liquid crystal display located immediately beneath the touch panel. * 17
16. An interface according to Claim 15, wherein the liquid ciystal display is adapted to display the pattern of keys only when the mterface is operating in its keyboard mode.
17. An interface according to any preceding Claim, wherein said means for switching between a keyboard mode and a mouse mode comprises one or more switches or buttons provided alongside the touch panel, together with LED or other * indicators adapted to indicate that the user interface is "on" and which mode is currently in operation.
18. An interface according to any of Claims I to 16, wherein the pattern of keys for the keyboard is displayed in a keyboard area of said touch screen, and wherein said means for switching between a keyboard mode and a mouse mode comprises one or more additional keys located in a portion of the touch panel outside both the keyboard area and the pointer control area.
19. An interface according to any preceding Claim, including means adapted to IS communicate an absolute pointer position in the pointer mode, in which points on the visual display unit and on the pointer control region map to each other, to the central processing unit, which means are adapted to employ the PS2 or USB mouse standards for relative mouse movements by detecting every detected position as a relative displacement from an origin both on the touch screen and on the monitor/visual display unit or from a point close to such origin.
20. A computer comprising a central processing unit, a monitor/visual display unit and an interface according to any preceding Claim.
21. A computer according to Claim 20, wherein at least said touch screen is provided as part of a shop front window.

22. A laptop computer comprising an interface according to Claim 11, in which the entire surface of the laptop is completely physically sealed, with connections for power supply and for connection to peripheral devices through said physical seal.
22. A user interface for a computer having a central processing unit and a monitor/visual display unit, the interface being substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
23. A computer substantially as hereinbefore described with reference to and as shown in the accompanying drawings.