WO2003029950A2

WO2003029950A2 - Input device for electronic equipment

Info

Publication number: WO2003029950A2
Application number: PCT/GB2002/004452
Authority: WO
Inventors: Ilan Zadik Samson
Original assignee: Ilan Zadik Samson
Priority date: 2001-10-04
Filing date: 2002-10-02
Publication date: 2003-04-10
Also published as: GB0123916D0; GB2380583A; WO2003029950A3

Abstract

An input device for electronic equipment is described which comprises a display screen (16). Objects (18), which may be smaller in size than a fingertip, are displayed on the screen (16) for selection by the user. A touch pad detects the position of a fingertip which is used to point at one of the displayed objects. The object at which the user is currently pointing is highlighted (22) to distinguish it from the other objects (18) available for selection. To avoid incorrect data entry, after its selection, the highlighted object can inputted into the electronic equipment under the control of the same fingertip without the need for the fingertip to be removed from the screen.

Description

INPUT DEVICE FOR ELECTRONIC EQUIPMENT

This invention relates to the manual inputting, without additional aids, of data into devices that are too small to have a keyboard and/or where items that need to be displayed on the screen for individual manual selection (selectable items) are smaller than a fingertip, that is, devices such as calculators, palm top computers, mobile communication devices, wrist instruments, controllers, special purpose equipment, and other electronic equipment.

Mobile phones utilise a keypad having upwards of twelve protruding keys, each suitable for fingertip actuation (throughout the present specification, the word "fingertip" is used to include the tip of the thumb as well as a finger) . These keys relate to digits 0 - 9 and some further keys for performing other specific functions. Text entry may be accomplished by assigning to each numeric key three alphabetical characters. The user is required to press the same numerical key repeatedly until the correct character is inputted. This may be confusing and is time consuming. Methods of avoiding this delay have been proposed in the form of predictive text messaging which attempts to predict the word the user is in the process of entering based on the letters already chosen. Although far quicker, it is not intuitive to use and it suffers from the disadvantages that unknown words often require tedious corrections and the user must constantly be on the lookout for incorrect predictions.

Palm top computers and personal organisers use a stylus. This is a pointer that behaves like a pen and writes on. a touch sensitive screen creating an electronic mark on the (normally LCD) screen. These may be combined with character recognition, so that handwriting ("graffiti") may be "read" by the device. Alternatively, a selection of small alphanumeric characters is provided on screen, and the user is required to use the stylus in order to select the desired character. This is disadvantageous in that it requires two hands to operate and also the stylus is awkward to use and may be easily lost.

In mobile telephones, as described in EP 0689 122, it has been proposed in addition to the usual keys, which are numbered 0 to 9 and can also be used to select alphabetic characters, to provide a touch pad that is associated with a keyboard and to display on a screen the currently selected character. This proposal is intended to teach users to use keypads without looking at the keys, i.e. the user is taught to rely on touch and visual confirmation is given on the screen of the key being touched before it is depressed. The present invention is not concerned with devices having separate keyboard and screens, it is intended only for devices having touch sensitive screens. In such devices, the user must look at and point to the screen to select an object and it is important that the user should not have to look at two different parts of the screen to determine if the correct selection is being made.

With progress in chip manufacture, electronic devices are becoming ever smaller, their si2e eventually being limited by the size of the data input device. There is therefore a need to facilitate data entry by means of a small input device which comprises a touch sensitive screen without a separate keyboard.

EP 1 191 403 which is believed to represent to closest prior art to the present invention discloses a graphical user interface for devices having small touch sensitive displays. In an apparatus, such as a PDA (personal digital assistant) , a touch sensitive screen is used to display objects that can be selected by means of the user's finger. A cursor is displayed on the screen in front of the point of contact of the user's finger and when the position of the cursor coincides with the desired object it can be selected by tapping twic-j with the finger on the screen. The first tap serves to define the position of the cursor and the second serves to enter the position of the cursor as input into the apparatus .

In the latter proposal, it is important that the position on the screen where the finger is tapped, at least the first time, should correspond to the previously displayed position of the cursor. Because the user must remove his finger to tap on the screen, there is a chance that a wrong selection may be made and for this reason the apparatus carries out a check to ensure that the position defined by the first tap matches the position of the cursor before the finger was lifted from the display. If the positions to do not match, the selection process has to be repeated, which is tedious and frustrating to the user.

With a view to mitigating the foregoing disadvantage, the present invention provides an input device for electronic equipment comprising a display screen, means for driving the screen to display a choice of selectable objects, the size and/or separation of the displayed objects being smaller than a fingertip, a touch pad associated with the display screen for detecting the position of a fingertip pointing at one of the displayed objects, means for determining which of the displayed objects is the selected object which corresponds to the currently sensed fingertip position, and means for highlighting the selected object to distinguish the selected object visually from the other objects available for selection, characterised by means enabling the currently selected object to be inputted into the electronic equipment under the control of the same fingertip without the need for the fingertip to be removed from the screen after the desired object has been selected.

The signal inputted into the computer will of course not comprise the selected object, it will merely consist of a position of the fingertip on the touch sensitive screen from which the electronic equipment can infer which object has been selected.

As is the case in E? 1 191 403, the area on the screen to which the user must point in he present invention to select a given object is smaller than the area of a fingertip. This is made possible by the fact that though the entire fingertip contact area may be large, it is only necessary to compare a predetermined part of the contact area or imprint, such as its centre, with the positions of the displayed objects. The input device then provides visual feedback to advise the user of the currently selected object, thereby avoiding risk of an incorrect position of the fingertip being inputted into the electronic equipment. Because the fingertip is not moved between the selection of an object and the inputting of the data into the electronic equipment, there is little risk of the data inputted into the electronic equipment being different from that intended.

The objects displayed on the screen may correspond to an alphanumeric character, a function key, a cursor key or an icon to initiate operation of a program or to instruct the electronic equipment to perform any task, such as enlarging an area of an image .

The object that corresponds to the current fingertip position may be distinguished from the other objects available for selection by changing its brightness or its size or font, or by having it flash. The feedback to the user might even be an audible signal. The method most suitable to a small LCD display is to change from a positive to a negative image of the object, i.e. reversing the foreground and background colours. For simplicity, all such methods of visually distinguishing one object from the others will hereinafter be referred to as highlighting, An advantage of using a virtual (or 'soft') keyboard is that the order cf the characters can be rearranged, e.g. alphabetical, QWERTY etc., and letters of different language can be accommodated.

Entering of the currently highlighted object may be effected by increasing the pressure applied by the fingertip. The increase in pressure can be detected by means of a dedicated pressure sensitive switch disposed beneath the touch sensitive display. The switch may comprise a pair of contacts that complete a circuit when they touch one another, or it may be formed of two spaced plates the capacitance between which changes when pressure is applied. As a further alternative, materials are known which change conductivity when pressure is applied to them.

Alternatively, increased pressure may be detected by analysing the imprint of the fingertip. The increased pressure will result in contact being sensed over a larger area of the touch sensitive display. The equipment, which already analyses the imprint to determine, for example, its centre of gravity, may be programmed to detect a change in the total area of the imprint.

It is desirable to take steps to ensure that an undesired object is not accidentally inputted as a result of a slight movement of the finger while applying additional pressure. This can be achieved by holding the currently highlighted object in a temporary memory for a predetermined length of time and if the pressure is increased during that time or while the object is still highlighted then it is the contents of the memory that area inputted to the equipment.

It is also desirable to require an object to be selected for a fixed length of time before it is highlighted. In this way, if a user rapidly scans over the displayed objects, none of them will be highlighted until the fingertip hovers over the selected objected for a fixed length of time. Such a mode of operation is less confusing and distracting to the user and gives greater reassurance that the correct object has been inputted.

As an alternative to the application of increased pressure to input the highlighted object, the object may be automatically inputted if highlighted for more than a predetermined length of time. This embodiment of the invention is not currently preferred because it limits the speed at which data can be inputted.

It is desirable to provide audible feedback to the user to indicate that an object has been inputted to the electronic equipment. This will ensure that data is always inputted when so intended and will avoid the same data from being inputted repeatedly as a result of multiple application of pressure or prolonged holding of a fingertip in the same place.

If the input device is being used to enter text into a document or database that is being edited, then the text entry will itself provide visual feedback making the audible feedback unnecessary. It is therefore desirable to provide a means to enable the user to disable or attenuate the sound output .

The invention will now be descried further by way of example and with reference to the accompanying drawings in which:

Figure 1 shows a conventional mobile phone utilising an alphanumeric keypad as is common in the art,

Figure 2 shows a conventional calculator also utilising a keypad as is common in the art, Figure 3 shows a calculator of the invention which is physically smaller yet has more functions than the calculator shown in Figure 2 , and Figure 4 shows a PDA of the invention being used for word processing.

Figure 1 shows a conventional mobile phone 10 which comprises a keypad 12 with protruding keys. Data inputted via the keypad is displayed on an LCD screen 14. As well as keeping a database of phone numbers, it is nowadays common for mobile phones to be used for text messaging and for several other applications that require the keying in of alphanumeric data, such as the inputting of text. It is not therefore sufficient for the keypad 12 to simply provide for numerical input. Instead, in existing mobile telephones, the number keys on the key pad can each also be used to input additional characters, three or four different alphabetical characters being associated with each of the numbers 2 to 9. In order to input one of these additional characters, when the telephone is in text entry mode, the number key needs to be pressed repeatedly until the required letter appears on screen 14.

For example, in order to input the letter "k" the 5 key must be pressed twice when the phone is expecting a letter entry. Similarly, to input the letter "y", the 9 key must be pressed twice. Obviously this will be time consuming when a long name is to be keyed in.

The difficulty of keying in data into a small piece of electronic equipment is not restricted to a mobile telephone. Figure 2 shows a typical electronic calculator. Here a large number of keys is required to allow a range of different operators and functions to be inputted by the user. Scientific calculators become unwieldy on account of the number of keys require and it is ultimately the size of the keyboard that is the limiting factor in the design of an electronic calculator. The problem of data entry is of course also experienced with other compact forms of electronic equipment ranging from PDA's, to cameras to wrist mounted electronic equipment such as watches. The invention is applicable to any compact piece of equipment that requires manual data entry for any reason.

As an example of a data input device of the present invention, there is shown in Figure 3 a calculator capable of performing all the functions of the calculator in

Figure 2, if not more, yet being considerably smaller in size. The calculator has a touch sensitive screen 16 that replaces the numerous number and function keys of the calculator in Figure 2. When required, the screen shows a list of selectable objects 18. In this example the list comprises the digits 0 to 9, and various other switches, operators and functions, as normally found on a complex calculator.

Of course in applications where alphanumeric data is to be keyed in to the electronic equipment, then the displayed objects will include the letters of the alphabet. Thus in Figure 4, there is shown a PDA being used as a word processor. The objects 18 available for selection in this case are those one would expect to find on a standard keyboard and may if desired (though not shown) include cursor control keys and function keys . The entered text appears on a different part of the screen.

The objects 18 displayed on the touch sensitive screen 16 are all those that can be currently selected and the display of selectable objects may change under program control depending on the mode of operation of the equipment. The precise nature of the objects 18 and the purpose that they serve is not strictly material to the present invention. The purpose of the invention is to enable a large number of such objects to be displayed close to one another on the touch sensitive screen 16 yet to permit an individual object to be selected using a fingertip as opposed to a pen or a dedicated stylus.

To select an object, the user is required to point slightly beneath it with the tip of a finger 24 or a thumb. When,, as in the case of a keyboard, a large number of objects is available for selection, the imprint of the fingertip on the screen will be larger than the individual objects and the separation between them. When a fingertip is sensed by the touch sensitive screen and the fingertip remains stationary for a given length of time, then the position of the centre of gravity of the imprint (or some other geometrically defined point) is calculated and correlated with the positions of the displayed objects to identify the closest object. Because the fingertip is slightly beneath the selected object, its image is not obscured by the pointing finger 24 and it is possible therefore to provide feedback to the user regarding the currently selected object by highlighting it. In the case of Figures 3 and 4, a cursor square 22 is drawn around the selected object but any other form of highlighting as described earlier may be employed.

Though an object has been selected and its image has been highlighted to confirm the selection, no data has yet been entered into the electronic equipment. To effect data entry, the user is not required to use any other digit and data entry is carried out under the control of the fingertip that is being used for pointing.

In a first embodiment of the invention, the user is required to maintain the same object highlighted for more than a predetermined length of time. At the end of this time, an audible signal is preferably produced to indicate that data input has occurred and that the equipment is ready to receive another input. Such an embodiment is not costly to implement because it requires no further hardware but it has the disadvantage that it slows down the rate at which data can be keyed in. It is preferred instead to require the user to increase the fingertip pressure to cause the current selection to be inputted into the electronic equipment. In all embodiments of the invention, it is important to note that data entry is effected without the need to remove the fingertip from the display after an object has been selected.

Additional pressure may be detected by placing a separate switch beneath the entire touch sensitive screen 16. The switch may have contacts that are closed when additional pressure is applied or it may consist of two spaced conductive plates the capacitance between which is increased when the gap between the plates is reduced by the application of increased pressure. As a further possibility, a material can be used that changes its conductance under pressure. Such a separate switch provides a simple method of sensing the increase in applied pressure but of course adds to the cost of the equipment.

Instead, the increased pressure can be detected by sensing an increase in the area of the imprint of the fingertip. As the imprint is in any event analysed to ascertain its centre of gravity, the sensing of the increased pressure may be effected in software in the same analysis sub-routine.

Once again in this embodiment, once data has been entered into the electronic equipment, it is desirable for the equipment to provide audible feedback. This can be used to confirm that data has been entered and also avoids unintentional multiple entry.

The data that has been keyed in may now be displayed on a separate part of the screen. For example, in the case of - li ¬

the calculator of Figure 3 the highlighted digit 9 appears in the calculation window 20 after it has been keyed in and in the case of text entry into the word processor of Figure 4, the last entered character will be added to che previously entered text at the position of the cursor. Because this too provides feedback to the user that data has been entered, it may be desirable in some instances to suppress or attenuate the audible feedback, which can prove a nuisance in some situations.

Even though the invention avoids the need to remove the fingertip from the display to effect data entry, there may remain a risk of the fingertip moving slightly while the applied pressure is being increased. If this should occur, the entered object will be different from the one that was selected and highlighted. To avoid this risk, it is preferred to store the highlighted object in a memory for a brief time after it has been highlighted and if increased pressure is sensed during this time then it is the object stored in the memory that is used as input into the electronic equipment. In other words, if the fingertip should slip from one object to another while the pressure is being increased, the newly selected objected will only have been selected for a very short time before the fingertip pressure is increased, and in such an event the previously highlighted object is used for data input rather than the currently selected object.

It is further desirable to suppress the highlighting of any object if it has not been selected for more than a predetermined time. This is to avoid a confusing profusion of highlighted objects as the finger is slid from one location to another.

It is envisaged that in use, the user will be able immediately to move rapidly from one object to another, without any object being highlighted. Very soon (typically less than one tenth of a second) after the finger comes to rest on any object, that object will be highlighted. If it is not the desired object, then small movements of the finger, by sliding or rolling, will result in one of the adjacent objects being highlighted. As soon as the desired object is highlighted the user will increase the fingertip pressure and the highlighted object will be used for data input into the equipment even if the finger should move slightly while it is being depressed.

The input device may also be used in apparatus to edit text which has previously been entered. Again, a character that needs to be edited (for example, for deletion, moving or replacement) would be selected by pointing at it, it would then be highlighted and a possible correction in identifying the item to be edited would be made by shifting/rolling the finger, the correct selection then confirmed by pressing harder or by sustaining the highlighting by the continued presence of the finger for a given duration.

Selecting a passage could be performed by keeping the finger in touch with the screen after the first selection and sliding the finger to the end-character which is entered in the same way as above. Lifting the finger and touching any point in the highlighted passage, and then sliding the finger, would drag the passage to a location which, again, is identified as above. 'Cursor positioning' between two characters could be afforded by back-and- forth selection of two neighbouring characters.

The top surface of the screen could have a relief, to provide tactile feedback to the user, which would be particularly useful for mobile phones if the soft keypad were used in place of a mechanical keypad.

Claims

1. An input device for electronic equipment comprising a display screen (16), means for driving the screen to display a choice of selectable objects (18) , the size and/or separation of the displayed objects being smaller than a fingertip, a touch pad associated with the display screen (16) for detecting the position of a fingertip pointing at one of the displayed objects (18), means for determining which of the displayed objects (18) is the selected object which corresponds to the currently sensed fingertip position, and means (22) for highlighting the selected object to distinguish the selected object visually from the other objects available for selection, characterised by means enabling the currently selected object to be inputted into the electronic equipment under the control of the same fingertip without the need for the fingertip to be removed from the screen after the desired object has been selected.

2. An input device as claimed in claim 1, wherein the objects displayed on the screen correspond to one or more of alphanumeric characters, function keys, cursor keys and program execution icons .

3. An input device as claimed in claim 1 or 2, wherein the selected corresponding to the current fingertip position is distinguished from the other objects available for selection by reversing the foreground and background colours .

4. An input device as claimed in any preceding cLaim, wherein an object is inputted into the equipment if highlighted for more than a predetermined length of time.

5. An input device as claimed in any of claim 1 to 3 , wherein means are provided for sensing the application of increased fingertip pressure to input the currently highlighted objected into the electronic equipment.

6. Ar. input device as claimed in claim 5, wherein the means for sensing the application of increased fingertip pressure comprises a separate switch.

7. An input device as claimed in claim 6, wherein the separate switch comprises contacts that complete an electrical circuit when increased pressure is applied.

8. An input device as claimed in claim 6, wherein the separate switch comprises a pair of plates and means for measuring the capacitance between the two plates.

9. An input device as claimed in claim 6, wherein the separate switch comprises a material of which the conductance changes in response to the application of pressure .

10. An input device as claimed in claim 5, wherein the means for sensing the application of increased fingertip pressure comprise means for analysing the area of the fingertip imprint .

11. An input device as claimed in any of claims 5 to 10, further comprising a memory for storing the currently highlighted object for a predetermined length of time after it has ceased to be selected and means for inputting the contents of the memory into the electronic equipment if increased fingertip pressure is sensed during said predetermined length of time.

12. An input device as claimed in any preceding claim, wherein an object is only highlighted after it has been selected for more than a predetermined time.

13. An input device as claimed in any preceding claim, further comprising a sound generator to provide the user with audible feedback each time data input occurs.

14. An input device as claimed in claim 12, wherein means are provided for switching off or attenuating the sound output of the sound generator.

15. An input device as claimed in any preceding claim, wherein the top surface of the display screen has a relief.