WO2000057266A1

WO2000057266A1 - Computer input device

Info

Publication number: WO2000057266A1
Application number: PCT/GB2000/000973
Authority: WO
Inventors: Gary Keith Dalton
Original assignee: British Telecommunications Public Limited Company
Priority date: 1999-03-23
Filing date: 2000-03-15
Publication date: 2000-09-28
Also published as: AU3181800A

Abstract

A computer input device is formed from a touch-sensitive screen and flexible membrane over the screen. The flexible membrane is marked to indicate touch input locations.

Description

COMPUTER INPUT DEVICE

The present invention relates to a computer input device, using the term "computer" broadly to denote all sorts of systems that carry out processing functions in response to user input. The invention is relevant, for example, to dedicated computer systems, such as a desktop computer, or a handheld PDA (personal digital assistant), and also to other systems including embedded computer processors, such as multimedia information kiosks, an intelligent mobile phone, or an intelligent remote control module for an audio-visual system. For many years, the most commonly used computer input devices have been a typewriter-like keyboard, possibly supplemented by a pointing device such as a mouse, trackball or touchpad. Increasingly, however, there has been a need to find alternative input devices. For example, for a multimedia kiosk, such as BT's Touchpoint (trademark) kiosk, a touch-sensitive screen or "touchscreen" has been used as a combined display and input device. The touchscreen is more robust than a keyboard, and requires less skill on the part of the user. However, the graphical interface for the kiosk then has to be carefully designed to function with the relatively coarse control available via the touchscreen. In the field of portable computing devices such as sub-notebook personal computers, PDA's and intelligent mobile phones, a number of different approaches have been tried, including miniaturised keyboards, touchscreens, and handwriting recognition. These all suffer limitations: miniaturised keyboards are too small for touch-typing, small touchscreens require precision from the user if errors are not to be made, and handwriting recognition imposes a large processing overhead and offer only limited accuracy. According to a first aspect of the present invention, there is provided a computer input device comprising a touchscreen display; and a flexible membrane overlying the touchscreen display and including markings defining a plurality of touch input locations. The present invention provides a modification to conventional touchscreen input systems that significantly enhances their ease of use. This achieved by using a flexible membrane over the touchscreen and providing markings in or on the membrane that define touch input locations. It is found that this greatly reduces the problems of user mistakes arising from an adjacent location being touched instead of the intended location. As a result, input locations can be more closely spaced than hitherto, making it possible for the input device to be used with a conventional user interface such as the GUI's (graphic user interfaces) commonly used on desktop personal computers, with little or no modification of that interface being necessary. At the same time, the invention maintains the ergonomic advantages of the combined display/input offered by the touchscreen, by contrast with systems in which the input device is separate from the display.

Preferably the markings include modifications in the profile of the flexible membrane.

It is particularly advantageous if the markings include appropriate shaping of the profile of the membrane, since then, as well as indicating to the user the touch locations, the markings can also serve to modify the effective sensitivity of the combined touchscreen/membrane system so as to reduce the risk of the wrong area receiving a touch input. Alternatively, or in addition, the markings may include surface markings printed on the membrane.

Preferably the membrane is arranged to be releasably fitted to the touchscreen.

A further benefit of the present invention in its preferred implementation, is that the membrane may be changed, for example in order to tailor the user interface to different applications having different graphical interfaces running on the computer, or in order to replace a membrane that has become damaged or dirty through use. The user might purchase a package comprising a program, for example on a CD-ROM together with a corresponding membrane for fitting to the touchscreen. Preferably the membrane includes one or more keys formed integrally in the membrane

According to a second aspect of the present invention, there is provided a system comprising: a) a machine readable medium carrying a computer program, the computer program including a graphical user interface arranged to generate a display of graphical elements at predetermined locations on a display screen; b) a touchscreen display; and c) a flexible membrane arranged in use to overlie the touchscreen display and including, in positions corresponding to the said predetermined locations markings defining a plurality of touch input locations

The invention also encompasses computers incorporating input devices or systems in accordance with the first or second aspects

Systems embodying the present invention will now be described in further detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagram showing a multimedia kiosk including an input device embodying the invention;

Figures 2a to 2d illustrate alternative profiles for touch locations in a flexible membrane;

Figure 3 shows a layout for a keyboard in a flexible membrane;

Figures 4a and 4b show handheld computer terminals embodying the invention.

As shown in Figure 1 , a multimedia kiosk 1 includes a touch-sensitive cathode ray display screen 2. Such a display screen is termed a "touchscreen". The screen 2 is connected to a microcomputer 3 mounted within the kiosk housing, out of sight from the user. The microcomputer 3 in this example has a Pentium II microprocessor and runs a commercially available operating system such as Windows NT (trademark) or LINUX (trademark). A transparent elastomer membrane 4 is releasably fixed to the screen 2 and overlies the screen 2. The membrane 4 includes markings 5 defining touch input locations. The markings may be, for example, rectangular ridges in the membrane that outline buttons for the user to push. The markings are at predetermined locations with respect to the screen 2, and a program running on the microcomputer 3 generates and displays graphical elements at those locations. The markings guide the user both visually and by touch to ensure that the user touches the screen with a finger in the appropriate location. For ease of illustration, the computer-generated display in the example of Figure 1 is shown as comprising a pair of triangular buttons. The computer detects any touch input from the user in these locations and responds accordingly, for example by moving forwards or backwards through a sequence of web pages shown on the display. The membrane in this example is a formed from a transparent polyurethane elastomer with a thickness of around 2mm. It includes a pair of apertures towards one edge. In use these apertures locate on lugs fixed on the screen housing at its edge so as to hold the membrane in a fixed position with respect to the screen. The membrane may also be held, for example, by a spring-loaded along one or more of the edges of the screen. Other materials may be used for the membrane. For example, it may be formed from a largely transparent silicon rubber, or from a silicon rubber/polyurethane laminate.

In this example, the touchscreen is a resistive device. Such devices are available commercially from a number of manufacturers including KDS Pixel Touch. The touchscreen has a top, outer layer formed from a hard polyester material. An inside layer is provided by a transparent conductive coating. A bottom layer is formed from a glass substrate with a uniform conductive coating. The conductive layers are held apart by separator dots. When the screen is touched, light pressure on the screen is sufficient to produce localised contact between the conductive layers, and the position of the contact can be determined from the resistance of the resulting circuit. The touchscreen has a resolution of 100,000 touch points per square inch.

Figures 2a to 2b show a number of alternative forms for buttons in the membrane. The buttons are shown both in plan and in cross section. Figure 2a shows rectangular bordered touch areas as already described. Figure 2b shows a button formed as a key with a small localised touch region on its underside that makes contact with the touch sensitive screen, and a larger button on the side offered to the user. Figure 2c shows a flexible rocker button with a snap-over action. Keys such as those shown in 2b and 2c are moveable and provide tactile feedback to the user. Figure 2d shows "zebra stripe" progressive scale buttons. These might be used to implement an analogue-type control function, for example a volume control. One possible use for the overlay is to provide an on-screen keyboard. Figure 3 shows the format of an overlay used for this purpose. It includes alphanumeric keys, such as that referenced 31 , and function keys such as that referenced 32. The overlay also includes borders for regions such as that referenced 33 that correspond to a field of touch locations rather than an individual location. This might be used, for example, as a touchpad to control a pointer. The raised boundary facilitates accurate use of the touchpad and helps to prevent inadvertent operation of adjacent controls. The labels for the keys are generated by the computer and displayed on the screen and are visible to the user through the transparent membrane. The keys may be in a conventional layout, for example the QWERTY layout. The layout may be changed under the control of the computer software, for example to the DVORAK layout, or to a layout for a different alphabet, for example with Greek characters. Figures 4a and 4b show the overlays of the present invention in use on a handheld wireless terminal used, in this example, in conjunction with a wireless LAN. In the example of Figure 4a, the overlay is the keyboard illustrated in Figure 3 and might be used, for example, for a note-taking application. In the example shown in Figure 4b, another overlay has been substituted. In this case the overlay is for use in conjunction with a computer game and includes directional control buttons. The program may have been purchased by the user on a CDROM 42 that is loaded into the terminal via a workstation of the wireless LAN. An overlay designed for use with the game is supplied with the CDROM and is fitted by the user to the terminal. As for the keyboard, the terminal generates a display of an appropriate graphical element at the location corresponding to the button. For such an application, piezoelectric elements may be integrated into the membrane and are used to provide tactile effects to the user. The portions of the overlay containing the piezoelectric elements, and strip connectors linking the elements to the terminal, are made opaque, for example sby overprinting.

Claims

1 A computer input device comprising a) a touchscreen display, and b) a flexible membrane overlying the touchscreen display and including markings defining a plurality of touch input locations

2. A computer input system comprising a) a machine readable medium carrying a computer program, the computer program including a graphical user interface arranged to generate a display of graphical elements at predetermined locations on a display screen, b) a touchscreen display, and c) a flexible membrane arranged in use to overlie the touchscreen display and including, in positions corresponding to the said predetermined locations markings defining a plurality of touch input locations

3 A device or system according to claim 1 or 2, in which the markings include modifications in the profile of the flexible membrane.

4. A device or system according to any one of the preceding claims, in which the membrane is arranged to be releasably fitted to the touchscreen

5. A device or system according to any one of the preceding claims, in which the membrane includes one or more keys formed integrally in the membrane.

6. A device or system according to claim 5, in which a plurality of keys are laid out in the membrane as a keyboard for typing

7 A device or system according to any one of the preceding claims, in which at least part of the membrane is generally transparent.

8. A device or system according to claim 7, in which substantially all of the membrane is generally transparent

9. A computer including an input device or input system according to any one of the preceding claims

10. A handheld computer including an input device or input system according to any one of the preceding claims,

11. A multimedia kiosk including an input device or input system according to any one of the preceding claims