Group 1 – Google’s Responsive Claim Construction Brief 

(Civil Case Nos. 6:20-cv-00571-ADA, 6:20-cv-00578-ADA, 6:20-cv-00583-ADA, and 6:20-

cv-00584-ADA) 

EXHIBIT #1 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 1 of 13
(12) United States Patent 

Rainist0 

US007 777728B2 

US 7,777,728 B2 

Aug. 17, 2010 

(10) Patent No.: 

(45) Date of Patent: 

(54) MOBILE COMMUNICATION TERMINAL 

(75) Inventor: Roope Rainisto, Helsinki (FI) 

(73) Assignee: Nokia Corporation, Espoo (FI) 

(*) Notice: Subject to any disclaimer, the term of this 

patent is extended or adjusted under 35 

U.S.C. 154(b) by 1082 days. 

(21) Appl. No.: 11/384,206 

(22) Filed: Mar 17, 2006 

(65) Prior Publication Data 

US 2007/0216658A1 Sep. 20, 2007 

(51) Int. Cl. 

G06F 3/04 (2006.01) 

(52) U.S. Cl. ........................ 345/173; 34.5/169; 345/168 

(58) Field of Classification Search ................. 345/156, 

345/168, 169, 172-174, 178, 179 

See application file for complete search history. 

(56) References Cited 

U.S. PATENT DOCUMENTS 

5,748,512 A * 

6,614422 B1 

2004/0001.048 A1* 

5/1998 Vargas ........................ TO8,142 

9, 2003 Rafii et al. 

1/2004 Kraus et al. ................. 345,173 

1 OO 

110 - ABC 

is 2 

fight j k Tölä 

2004/0046744 A1* 

2004/O140956 A1* 

2004/O155869 A1* 

2006/0O28450 A1* 

2006, OO38789 A1* 

3/2004 Rafii et al. .................. 345,168 

7/2004 Kushler et al. ........ ... 345,168 

8/2004 Robinson et al. ... ... 345,168 

2/2006 Suraqui ............ ... 345,169 

2/2006 Ban et al. ................... 345/169 

* cited by examiner 

Primary Examiner—Amr Awad 

Assistant Examiner—John Morris 

(74) Attorney, Agent, or Firm—Alston & Bird LLP 

(57) ABSTRACT 

It is presented a text input method for an electronic apparatus with a touch sensitive display, the apparatus comprising a user 

interface, wherein a virtual keyboard is displayed on the 

display So as to facilitate input of an intended character for a 

user by touching keys of the virtual keyboard with a pointer, 

wherein the intended character is determined by considering: 

a plurality of candidate characters, the plurality of candidate 

characters being determined with regard to a raw distance, the 

raw distance being a distance between a first position, the first 

position being a position of a detected touch of the pointer, 

and a position corresponding to a character, and linguistic 

probabilities of each character of the plurality of candidate 

characters being an intended character. A corresponding elec 

tronic apparatus and computer program product are also pre 

sented. 

17 Claims, 6 Drawing Sheets 

seasis. Russex-searwater 

-102 

163 164 

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Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 2 of 13
U.S. Patent Aug. 17, 2010 Sheet 1 of 6 US 7,777,728 B2 

Fig 1 

 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 3 of 13
U.S. Patent Aug. 17, 2010 Sheet 2 of 6 US 7,777,728 B2 

 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 4 of 13
U.S. Patent Aug. 17, 2010 Sheet 3 of 6 US 7,777,728 B2 

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32 

Data communications network 

(e.g. WAN, LAN) 

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42 

Fig. 4 

 

 

 

 

 

 

 

 

 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 5 of 13
U.S. Patent Aug. 17, 2010 Sheet 4 of 6 US 7,777,728 B2 

: 56 : 

Virtual keyboard wil: ; 

intelligent char. : : 

Selection : functionality 0 e o O & O w v 0 . F. V. 

55 

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tra and, finally, the fourth one. 

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Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 6 of 13
U.S. Patent Aug. 17, 2010 Sheet 5 of 6 US 7,777,728 B2 

 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 7 of 13
U.S. Patent Aug. 17, 2010 Sheet 6 of 6 US 7,777,728 B2 

100 

was sealeisrara asa-Ya-yearwa-ax 

-102 

162 163 164 

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110 -Agca's figh KT8. 

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Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 8 of 13
US 7,777,728 B2 

1. 

MOBILE COMMUNICATION TERMINAL 

FIELD OF THE INVENTION 

Embodiments of the present invention generally relates to 5 

electronic equipment capable of text input, and more particu 

larly to a text input method for an electronic apparatus having 

a user interface with a touch sensitive display. 

BACKGROUND OF THE INVENTION 10 

Apparatuses with touch-sensitive display Screens often 

provide a virtual key-board feature in the user interface to 

facilitate text input. This works by displaying a virtual key 

board, often resembling a real-life keyboard, on the display 15 

screen. By tapping with a writing tool on individual buttons or 

keys of the virtual keyboard, the user may input Successive 

characters which aggregate to a text input shown in a text 

input field on the display Screen. 

Since text input with a writing tool on a touch-sensitive 20 

display screen by nature will be slower and more error prone 

than manual input on a hardware (physical) keyboard, it is 

generally desired to improve the accuracy and input speed. 

One approach in this regard known in the art is the provision 

of word completion functionality in the user interface for 25 

automatic presentation of full word candidates to what the 

user has currently inputted in the form of a partial word. 

For instance, if the user writes “wo' by tapping on the “w” 

key and then the “o' key of the virtual keyboard, the word 

completion functionality can predict full word candidates 30 

such as “word”, “world' and “wormhole' and present them 

on the display screen in a selectable manner. A desired one of 

these candidates may be selected by the user by tapping on it, 

and the full word thus selected will automatically replace the 

current partial word input on the display Screen. 35 

While word completion functionality certainly has its ben 

efits, some problems are associated therewith. In more par ticular, since the apparatus involved will typically be a small 

portable device such as a mobile terminal or a pocket com 

puter, the available display screen space will be a limited 40 

resource. Thus, displaying multiple full word candidates any 

where in the user interface may potentially block other rel 

evant information to be displayed (such as actual application 

contents). 

Another problem with this input method is that the user is 45 

dependent on what words are in the dictionary of the device. 

Another problem is that the user constantly has to check what 

Suggestions are provided to see if there is a matching word, 

whereby the user has to concentrate partly on finding the 

correct characters with the stylus and partly on checking 50 

Suggested words, leading to inefficient typing. Moreover, this 

Solution requires that dictionaries are stored locally in the 

device for all input languages that need to be supported, which requires a significant amount of storage space. 

Consequently, there is a need for a novel and improved 55 

method for a user to efficiently input text on a device with a 

touch sensitive display. 

SUMMARY OF THE INVENTION 

60 

In view of the above, an objective of certain embodiments 

of the invention is to solve or at least reduce the problems 

discussed above. 

According to a first aspect of the invention there has been 

provided a text input method for an electronic apparatus with 65 

a touch sensitive display, the apparatus comprising a user 

interface, wherein a virtual keyboard is displayed on the 

2 

display So as to facilitate input of an intended character for a 

user by touching keys of the virtual keyboard with a pointer, 

wherein the intended character is determined by considering: 

a plurality of candidate characters, the plurality of candidate 

characters being determined with regard to a raw distance, the 

raw distance being a distance between a first position, the first 

position being a position of a detected touch of the pointer, 

and a position corresponding to a character, and linguistic 

probabilities of each character of the plurality of candidate 

characters being an intended character. This method provides 

a novel and inventive way to reduce the risk of the user 

making mistakes when using a virtual keyboard to enter text. 

The plurality of candidate characters may be determined 

also with regard to a direction of movement of the pointer. This provides a better way to predict the intended character. 

The text input method may comprise the steps of detecting 

a touch on the touch sensitive display at a first position, 

calculating a tap distance and a tap direction between the first 

position and a second position, the second position being a 

position of a previously detected touch position, associating a 

key candidate area, the candidate area having a predetermined 

spatial extent, being associated with the first position, creat 

ing a candidate list of characters, each character in the can 

didate list having at least part of its respective key area over 

lapping the candidate area, for the each character in the 

candidate list, determining a raw distance between a position corresponding to the each character and the first position, determining a probability value for the each character in the 

candidate list, the probability value being the linguistic prob 

ability of the each character, for the each character in the 

candidate list, calculating a weighted distance, the weighted 

distance being calculated using the raw distance and the prob ability value, and determining the intended character, the 

intended character being determined as the character in the 

candidate list with a smallest weighted distance. 

The step of determining a probability value may involve 

determining a probability value based on at least one previ ously input character. Previously input characters provide a 

readily available base for linguistic probabilities of new char 

acter entries. 

The step of determining a probability value may involve 

determining a probability value based on at least one previ 

ously input character and an input language. Using an input 

language enhances the accuracy of the method, as linguistic 

probabilities for the same letter combinations differ between 

languages. 

The step of associating a candidate area with the first posi 

tion may involve determining the candidate area with consid 

eration to the tap distance and the tap direction. Using the tap 

direction allows a more controlled candidate area, resulting in 

a better candidate list, eliminating highly unlikely candidates. 

The step of associating a candidate area with the first posi 

tion may involve determining the candidate area, the candi 

date area being relatively longer along a first axis and rela 

tively shorter along a second axis, the first axis being parallel 

to the tap direction and the second axis being perpendicular to 

the first axis. The candidate area may be of an elliptical or a 

teardrop shape. This improves accuracy, as there is a larger 

probability of missing the intended character along the tap 

direction. 

In the step of for the each character in the candidate list, calculating a weighted distance, the weighted distance may 

be proportional to both the raw distance and the difference 

between the constant one and the probability value. 

The step of detecting a touch on the touch sensitive display 

at the first position may involve detecting a duration of the 

touch, and the method may comprise the further step, after the 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 9 of 13
US 7,777,728 B2 

3 

step of determining an intended character, of conditionally 

determining the intended character to be a character directly corresponding to the first position, the condition comprising 

at least that the touch has a duration being longer than a 

threshold duration. This allows the user to insist on the 

intended character being the character having the activation 

area of the first position. This may be particularly useful while 

entering passwords, web addresses, text in a language differ 

ent from the input language, etc. 

A second aspect of the present invention is an electronic 

apparatus comprising a user interface with a touch sensitive 

display, and a controller coupled to the display, the user 

interface including a virtual keyboard which is presentable on 

the display so as to facilitate input of an intended character for 

a user by touching keys of the virtual keyboard with a pointer, 

each key being associated with a respective key area, the user 

interface including a character selection functionality for 

determining an intended character, the controller being adapted for determining the intended character considering: a 

plurality of candidate characters, the plurality of candidate 

characters being based on a direction of movement of the 

pointer, and linguistic probabilities of each character of the 

plurality of candidate characters being an intended character. 

This electronic apparatus provides a novel and inventive way 

to reduce the risk of the user making mistakes when using a 

virtual keyboard to enter text. 

The electronic apparatus may be in the form of a pocket 

computer. Virtual keyboards are commonly used in pocket 

computers and would benefit from increased text entry accu 

racy and speed. 

The electronic apparatus may be in the form of a mobile 

terminal for a mobile telecommunications network. Virtual 

keyboards are commonly used in pocket computers and 

would benefit from increased text entry accuracy and speed. 

A computer program product directly loadable into a 

memory of a processor, where the computer program product 

comprises program code for performing the method as 

defined in the first aspect when executed by the processor. 

Other objectives, features and advantages of the present 

invention will appear from the following detailed disclosure, 

as well as from the drawings. 

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, 

unless explicitly defined otherwise herein. All references to 

“a/an/the element, device, component, means, step, etc. are 

to be interpreted openly as referring to at least one instance of 

the element, device, component, means, step, etc., unless 

explicitly stated otherwise. The steps of any method disclosed 

herein do not have to be performed in the exact order dis 

closed, unless explicitly stated. 

BRIEF DESCRIPTION OF THE DRAWINGS 

Embodiments of the present invention will now be 

described in more detail, reference being made to the 

enclosed drawings. 

FIG. 1 is a perspective view of an electronic apparatus 

according to one embodiment, in the form of a pocket com 

puter which is shown in a typical operating position in the 

hands of a user. 

FIGS. 2 and 3 are different perspective views of the pocket 

computer of FIG. 1. 

FIG. 4 illustrates a computer network environment in 

which the pocket computer of FIGS. 1-3 advantageously may 

be used for providing wireless access for the user to network resources and remote services. 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

4 

FIG.5 is a schematic block diagram of the pocket computer according to the previous drawings. 

FIG. 6 is a front view of the pocket computer, demonstrat 

ing a typical display Screen layout of its user interface. 

FIG. 7 illustrates a typical disposition of the display screen 

layout, including a home view. 

FIG. 8 illustrates a display screen layout for text input into 

a text handling application in the pocket computer. 

FIGS. 9a and 9b are display screen snapshots that illustrate 

the intelligent character selection functionality according to one embodiment. 

DETAILED DESCRIPTION OF PREFERRED 

EMBODIMENTS 

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in 

which certain embodiments of the invention are shown. This 

invention may, however, be embodied in many different 

forms and should not be construed as limited to the embodi 

ments set forth herein; rather, these embodiments are pro vided by way of example so that this disclosure will be thor 

ough and complete, and will fully convey the scope of the 

invention to those skilled in the art. Like numbers refer to like 

elements throughout. 

With reference to FIGS. 1 to 3, an electronic apparatus according to an embodiment of the present invention will now 

be described. The pocket computer 1 of the illustrated 

embodiment comprises an apparatus housing 2 and a rela 

tively large touch-sensitive display screen 3 provided at a 

front side 2f of the apparatus housing 2. Next to the display 

screen 3 a plurality of hardware keys 5a-d are provided, as 

well as a speaker 6. 

More particularly, key 5a is a five-way navigation key, i.e. 

a key which is depressible at four different peripheral posi 

tions to command navigation in respective orthogonal direc 

tions (“up”, “down”, “left”, “right”) among information 

shown on the display Screen 3, as well as depressible at a 

center position to command selection among information 

shown on the display screen 3. Key 5b is a cancel key, key 5c 

is a menu or options key, and key 5d is a home key. 

In addition, a second plurality of hardware keys 4a-care 

provided at a first short side 2u of the apparatus housing 2. 

Key 4a is a power on/off key, key 4b is an increase? decrease 

key, and key 4c is for toggling between full-screen and normal 

presentation on the display screen 3. 

At a second short side 21 of the apparatus housing 2. 

opposite to said first short side 2u, there are provided an 

earphone audio terminal 7a, a mains power terminal 7b and a 

wire-based data interface 7c in the form of a USB port. Being touch-sensitive, the display screen 3 will act both as 

a visual output device 52 and as an input device 53, both of 

which are included in a user interface 51 to a user 9 (see FIG. 

5). More specifically, as seen in FIG.1, the user 9 may operate the pocket computer 1 by pointing/tapping/dragging with a 

pointer 9c such as a stylus or pen, held in one hand 9a, on the 

surface of the touch-sensitive display screen 3 and/or by actuating any of the hardware keys 4a-c, 5a-d (which also are 

included as input devices in the user interface 51) with the 

thumb and index finger of the other hand 9b. It is to be noted 

that a finger of the user may also be used as a pointer. 

As seen in FIG. 5, the pocket computer 1 also has a con 

troller 50 with associated memory 54. The controller is 

responsible for the overall operation of the pocket computer 1 

and may be implemented by any commercially available CPU 

(Central Processing Unit), DSP (Digital Signal Processor) or 

any other electronic programmable logic device. The associ 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 10 of 13
US 7,777,728 B2 

5 

ated memory may be internal and/or external to the controller 

50 and may be RAM memory, ROM memory, EEPROM 

memory, flash memory, hard disk, or any combination 

thereof. The memory 54 is used for various purposes by the 

controller 50, one of them being for storing data and program 

instructions for various pieces of software in the pocket com 

puter 1. The software may include a real-time operating sys 

tem, drivers e.g. for the user interface 51, as well as various applications. 

At least Some of these applications may be text handling applications 57, for instance in the form of a notes application 

(further shown in FIGS. 8, 9a, 9b), a messaging application 

(e.g. SMS, MMS, email), a contacts application, a word pro cessing application, etc. To facilitate text input, the user inter 

face 51 includes a virtual keyboard module 56 with intelligent character selection functionality, having the general purpose 

which has already been explained above. In addition to this, 

the user interface may include other text input means, such as 

a handwriting input module with a handwriting recognition engine. 

To allow portable use, the pocket computer 1 has a 

rechargeable battery. The pocket computer also has at least one interface55 for wireless access to network resources on at 

least one digital network. More detailed examples of this are 

given in FIG. 4. Here, the pocket computer 1 may connect to 

a data communications network 32 by establishing a wireless 

link via a network access point 30, such as a WLAN (Wireless 

Local Area Network) router. The data communications net 

work32 may be a wide area network (WAN), such as Internet 

or some part thereof, a local area network (LAN), etc. A 

plurality of network resources 40-44 may be connected to the 

data communications network.32 and are thus made available 

to the user 9 through the pocket computer 1. For instance, the 

network resources may include servers 40 with associated 

contents 42 such as www data, wap data, ftp data, email data, 

audio data, video data, etc. The network resources may also 

include other end-user devices 44. Such as personal comput CS. 

A second digital network 26 is shown in FIG. 4 in the form 

of a mobile telecommunications network, compliant with any 

available mobile telecommunications standard such as GSM, 

UMTS, D-AMPS or CDMA2000. In the illustrated exempli fying embodiment, the user 9 may access network resources 

28 on the mobile telecommunications network 26 through the 

pocket computer 1 by establishing a wireless link 10b to a 

mobile terminal 20, which in turn has operative access to the 

mobile telecommunications network 26 over a wireless link 

22 to a base station 24, as is well known perse. The wireless 

links 10a, 10b may for instance be in compliance with Blue 

toothTM, WLAN (Wireless Local Area Network, e.g. as speci 

fied in IEEE 802.11), HomeRF, WIMAX or HIPERLAN. 

Thus, the interface(s) 55 will contain all the necessary hard 

ware and software required for establishing Such links, as is 

readily realized by a man skilled in the art. 

FIG. 6 shows a front view of the pocket computer and 

indicates a typical display Screen layout of its user interface. 

A typical disposition of the display Screen layout, presenting 

a view of a home application (i.e., a start or base view that the 

user 9 may return to whenever he likes), is shown in more 

detail in FIG. 7. In FIG. 6, the hardware keys 5a-dare shown 

at their actual location to the left of the display screen 3 on the 

front Surface 2f of the apparatus housing 2, whereas, for 

clarity reasons, the hardware keys 4a-care illustrated as being 

located above the display screen 3 on the front surface 2feven 

while they actually are located at aforesaid first short side 2u 

(FIG. 2). 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

6 

With reference to FIG. 7, the layout of the display screen 3 

is divided into four main areas: a task navigator 60, a title area 

70, a status indicator area 74 and an application area 80. 

The application area 80 is used by a currently active appli 

cation to present whatever information is relevant and also to 

provide user interface controls such as click buttons, scrol 

lable list, check boxes, radio buttons, hyper links, etc., which 

allow the user 9 to interact with the currently active applica tion by way of the stylus 9c. One example of how a currently 

active application, in the form of a notes application, uses the 

application area 80 in this manner is shown in FIG.8. A name 

or other brief description of the currently active application 

(e.g. the notes application) and a current file or data item (e.g. 

the currently open text file) is given at 72 in the title area 70 

(e.g. “Notes—Report 1). In addition, by tapping in the title 

area 70, the user 9 may access a menu structure of the cur 

rently active application. 

The status indicator area 74 contains a plurality of icons 76 

that provide information about System events and status, typi cally not associated with any particular active application. As 

seen in FIG. 7, the icons 76 may include a battery charge indicator, a display brightness control, a Volume control as 

well as icons that pertain to the network interface(s) 55 and 

the ways in which the pocket computer connects to the net 

work(s) 32, 26. 

The task navigator 60, title area 70 and status indicator area 

74 always remain on screen at their respective locations, 

unless full screen mode is commanded by depressing the 

hardware key 4c. In Such a case, the currently active applica 

tion will use all of the display 3 and the areas 60 and 70 will 

thus be hidden. 

The task navigator 60 has an upper portion 62 and a lower 

portion 66. The upper portion 62 contains icons 63-65 which 

when selected will open a task-oriented, context-specific 

menu to the right of the selected icon. The context-specific 

menu will contain a plurality of task-oriented menu items, 

and the user 9 may navigate among these menu items and 

select a desired one either by the navigation key 5a or by 

pointing at the display screen 3. As seen in FIG. 7, the lower 

portion 66 represents an application Switcher panel with 

respective icons 67 for each of a plurality of launched appli 

cations. 

In FIG. 8, a text handling application in the form of a notes 

application is active, as indicated at 72 in the title area 70, and 

has control of the application area 80 of the display screen 

layout 100. The application area is divided into a text input 

field 102 and a virtual keyboard 110. Currently, there is no 

text input shown in the text input field 102. 

The virtual keyboard 110 is divided into four main groups 

of logical keys or buttons 120, 130, 140 and 150. Each such 

key has an activation area delimited by borders 153 which is 

indicated as a grey box having a icon or symbol representing 

the meaning of the key in question. In a well known manner, 

by pointing with the stylus 9c within the activation area, the 

user 9 may select the key. Alternatively or additionally, text 

input may be performed e.g. by handwriting with the stylus 

within the text input field 102. 

If the selected key is an alphanumeric key included in a 

character key group 130 or numeric key group 140, Such as a 

'd key 152, the corresponding alphanumeric character will 

be directly displayed in the text input field 102, as is well 

known perse. If, on the other hand, the selected key belongs 

to a control key group 120 or 150, a corresponding function 

will instead be performed, such as backSpace, carriage return, 

tabulation, Switch of character set, caps lock, etc. 

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US 7,777,728 B2 

7 

Referring now to FIGS. 9a and 9b, the virtual keyboard 

module 56 with its intelligent character selection functional 

ity will be described in more detail. 

The intelligent character selection is based on a method for 

automatically favoring likely characters in an input language 

when entering text by means of a virtual keyboard, while still 

allowing for the input of any type of text. Both language 

character frequency and human hand movement patterns are 

taken into account. 

To illustrate the method, an example where the user 9 

wishes to input the text dove will now be described in detail. 

In FIG. 9a, the user 9 has pressed stylus 9c on the screen at 

the position 161 for the letter d’. Accordingly, in the text 

input field 102, the text 104 'd' is displayed. A cursor 107 

indicates the position for Subsequent text entry. To input the 

next letter, 'o', the user 9 then lifts and moves the stylus along 

a path 162, and presses down the stylus at a new position 163. 

In the attempt to input text with a high speed, the user actually 

misses the intended letter and the new position of the stylus is 

just on the other side of the border 153 (see FIG. 8) within the 

activation area associated with the letter p, which is to the 

right of the letter o’. This type of mistake is unfortunate, but 

easy to make in this type of text entry. With virtual keyboards 

in the prior art, the letter p would have been registered, 

requiring the user 9 to recognize that the incorrect letter has 

been entered, and to correct the entry by erasing the incorrect 

entry and entering the correct letter. However, in this embodi 

ment of the present invention, the intended letter, o, would 

still be recognized. 

The method works as follows: 

The distance and angle between the new position 163 and 

the previous position 161 is calculated and a candidate area 

164 is calculated. 

The characters that fall sufficiently inside the candidate area 164 will be added to a candidate list of characters to be 

considered. Sufficiently inside can for example be that the 

center position of the character is inside the candidate area 

164, or that a certain percentage of the character area is within 

the candidate area 164. The candidate area 164 is longer along 

an axis of movement 162. Such as the depicted elliptical shape 

of the candidate area 164, or rectangular. One shape that has 

proven useful is a teardrop shape. The shape is longer along 

the axis of movement 162 due to there being a larger prob ability of missing the intended character along the axis of 

10 

15 

25 

30 

35 

40 

movement 162. In this example, for simplicity and clarity of 45 

the description, only characters o' and p make up the can 

didate list. 

For each of the characters in the candidate list, a probability 

that the character would appear after the previous character/ 

phrase/part of word is retrieved from memory, such as 

memory 54 in FIG. 5. In this example, using English, the 

probability of an o' appearing after a 'd may for example be 

0.1, and the probability of a p’ appearing after a 'd may for 

example be 0.001. The probabilities are based on language 

statistics, and may be based on the previous character, on two 

previously entered characters, on all previously entered char 

acters in the same word, etc. It is to be noted that the values of 

the probabilities mentioned here are mere illustrative 

examples. If the probability is based on one or two previous 

characters, this requires significantly less data to be stored in 

memory 54 than if a full dictionary would have to be stored. 

Consequently, the pocket computer 1 may support many 

more languages in a specific amount of memory. 

Furthermore, for each character in the candidate list, the 

distance from the current stylus position and the centerpoint 

of the character is determined. In this example, the distance 

from the new position 163 to the center of character 'o' is 2.8 

50 

55 

60 

65 

8 

millimeters, while the distance from the new position 163 to 

the center of the character p is 2.6 millimeters. Distance is 

typically measured in geometrical distance, not in pixels, as 

pixels are not necessarily perfectly square. 

Thena weighted distance is calculated for each characterin 

the candidate list. The weighted distance is based on the 

actual, or raw, distance and the probability of each character. 

One formula that may be used to calculate the weighted 

distance is as follows: 

D=(1-p)* D. (1) 

where D is the weighted distance, p is the probability and 

D, is the raw distance. With the formula (1), the weighted distances D, for 'o' and p, equates to 2.520 and 2.597, 

respectively (rounded off to three decimals). The character 

with the lowest weighted distance in the calculation will be 

initially indicated to be pressed down. Selection of this can 

didate is done by lifting up the stylus, as is usual. In this 

example, when the user 9 lifts the stylus, 'o' is therefore 

selected as the next character, since 'o' has the Smallest 

weighted distance, even though the new position is within the 

area for p. 

If the indicated candidate was not the character intended by the user 9, the user 9 can keep the stylus pressed down, for a 

short delay (e.g. about 0.8 seconds), whereby the target will 

move to the exact point where the stylus is pressed down. 

Alternatively or additionally, the user 9 corrected selection 

can be made by the user 9 moving the stylus/finger slightly 

while pressing down, whereby the current position of the 

stylus/finger should be used instead of the predicted candi 

date. In other words, exact input can be performed in an input 

style where the user 9 moves the stylus ever so slightly with 

each down press, for the pocket computer to consider the 

position by itself without considering probabilities. With 

these methods, the user 9 can still enter text where the letters 

are not the most probable letters, which in particular may be 

the case for passwords, web addresses, text input in a lan 

guage different from the input language, etc. 

FIG.9b illustrates how the user 9 continues to type, press ing the stylus at a new position 165 to type the letter v. The 

text input field 102 now shows the previously entered text 

104' ‘do’, with the cursor 107 positioned after this text 104". 

This time, the new position 165 is more accurate, and with no 

characters within the candidate Zone 166 having a probability being much higher than 'v'succeeding 'o', the letter v is 

selected. The user 9 then continues in the same manner to 

input 'e' to make up the intended word dove' (not shown). 

The invention has mainly been described above with ref 

erence to a few embodiments. However, as is readily appre 

ciated by a person skilled in the art, other embodiments than 

those disclosed above are equally possible within the scope of 

the invention, as defined by the appended patent claims. 

What is claimed is: 

1. A text input method for an electronic apparatus with a 

touch sensitive display, wherein a virtual keyboard is dis 

played on said display So as to facilitate input of an intended 

character for a user by touching keys of said virtual keyboard with a pointer, wherein the method comprises: 

detecting a touch of a first key on the touch sensitive dis 

play at a first position; 

defining a candidate area that has a configuration that is 

dependent upon a tap direction that extends between the 

first position and a second position, wherein the second 

position is a position of a previously detected touch of a 

second key of the touch sensitive display, and wherein 

said candidate area being relatively longer along a first 

axis and relatively shorter along a second axis, said first 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 12 of 13
US 7,777,728 B2 

axis being parallel to said tap direction and said second 

axis being perpendicular to said first axis; and 

determining said intended character by considering: 

a plurality of candidate characters disposed at least par 

tially within the candidate area, said plurality of can 

didate characters being determined with regard to a 

raw distance, said raw distance being a distance 

between said first position and a position correspond 

ing to a character, and 

linguistic probabilities of each character of said plurality 

of candidate characters being an intended character. 

2. The text input method according to claim 1, wherein 

each key is associated with a respective key area, said method 

comprising: 

calculating a tap distance and the tap direction between 

said first position and a second position, associating a candidate area with said first position, the 

candidate area having a predetermined spatial extent, 

creating a candidate list of characters, each character in 

said candidate list having at least part of its respective 

key area overlapping at least part of said candidate area, 

for said each character in said candidate list, determining said raw distance between a position corresponding to 

said each character and said first position, determining a probability value p for said each character in 

said candidate list, said probability value being said 

linguistic probability of said each character, 

for said each character in said candidate list, calculating a 

weighted distance, said weighted distance being calcu 

lated using said raw distance and said probability value, 

and 

determining said intended character, said intended charac 

ter being determined as the character in said candidate 

list with a smallest weighted distance. 

3. The method according to claim 2, wherein said step of 

determining a probability value involves determining a prob 

ability value based on at least one previously input character. 

4. The method according to claim 2, wherein said step of 

determining a probability value involves determining a prob 

ability value based on at least one previously input character 

and an input language. 

5. The method according to claim 2, wherein said step of 

associating a candidate area with said first position involves 

determining said candidate area with consideration to said tap 

distance and said tap direction. 

6. The method according to claim 2, wherein said step of 

associating a candidate area with said first position involves 

determining said candidate area. 

7. The method according to claim 1, wherein said candidate 

area is of an elliptical shape. 

8. The method according to claim 1, wherein said candidate 

area is of a teardrop shape. 

9. The method according to claim 2, wherein said step of 

for said each character in said candidate list, calculating a 

weighted distance, said weighted distance is proportional to 

both said raw distance and (1-p). 

10. The method according to claim 2, wherein said step of 

detecting a touch on said touch sensitive display at said first 

position involves detecting a duration of said touch, 

and said method comprises the further step, after said step of determining an intended character, of: 

conditionally determining said intended character to be a 

character directly corresponding to said first position, 

said condition comprising at least that said touch has a 

duration being longer than a threshold duration. 

11. An electronic apparatus comprising a user interface 

with a touch sensitive display, and a controller coupled to said 

display, said user interface including a virtual keyboard 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

10 

which is presentable on said display so as to facilitate input of 

an intended character for a user by touching keys of said 

virtual keyboard with a pointer, each key being associated 

with a respective key area, said user interface including a 

character selection functionality for determining an intended 

character, said controller being configured to: 

detect a touch on a first key of the touch sensitive display at 

a first position; 

define a candidate area that has a configuration that is 

dependent upon a tap direction that extends between the 

first position and a second position, wherein the second 

position is a position of a previously detected touch of a 

second key of the touch sensitive display and wherein 

said candidate area being relatively longer along a first 

axis and relatively shorter along a second axis, said first 

axis being parallel to said tap direction and said second 

axis being perpendicular to said first axis; and 

determine said intended character by considering: 

a plurality of candidate characters disposed at least par 

tially within the candidate area, said plurality of can 

didate characters being determined with regard to a 

raw distance, said raw distance being a distance 

between said first position and a position correspond 

ing to a character, and 

linguistic probabilities of each character of said plurality 

of candidate characters being an intended character. 

12. The electronic apparatus according to claim 11, in the 

form of a pocket computer. 

13. The electronic apparatus according to claim 11, in the 

form of a mobile terminal for a mobile telecommunications 

network. 

14. An apparatus comprising a memory of a processor and 

program code stored in the memory and configured to per 

form the method as defined in claim 1 when executed by said 

processor. 

15. The electronic apparatus according to claim 11, 

wherein said candidate area is an elliptical shape or a teardrop shape. 

16. An apparatus comprising a controller and a memory 

storing executable instructions that in response to execution 

by the controller cause the apparatus to at least perform the 

following: 

detect a touch of a first key on a touch sensitive display at 

a first position; 

define a candidate area that has a configuration that is 

dependent upon a tap direction that extends between the 

first position and a second position, wherein the second 

position is a position of a previously detected touch of a 

second key of the touch sensitive display and wherein 

said candidate area being relatively longer along a first 

axis and relatively shorter along a second axis, said first 

axis being parallel to said tap direction and said second 

axis being perpendicular to said first axis; and 

determine said intended character by considering: 

a plurality of candidate characters disposed at least par 

tially within the candidate area, said plurality of can 

didate characters being determined with regard to a 

raw distance, said raw distance being a distance 

between said first position and a position correspond 

ing to a character, and 

linguistic probabilities of each character of said plurality 

of candidate characters being an intended character. 

17. The electronic apparatus according to claim 16, 

wherein said candidate area is an elliptical shape or a teardrop shape. 

Case 6:20-cv-00571-ADA Document 38-1 Filed 02/12/21 Page 13 of 13