Character recognition and character input apparatus using touch screen and method thereof

A character input method using a touch screen, in which one or more areas requiring user input is defined in the touch screen, pre-recognized information is defined for each of the defined areas, character information is received by a user in one or more user desired areas among the defined areas, the character information is recognized using a character recognizer, and the recognized character information is updated in the user desired areas.

PRIORITY

This application claims priority under 35 U.S.C. §119(a) to a Korean Patent Application filed in the Korean Intellectual Property Office on Jul. 31, 2009 and assigned Serial No. 10-2009-0070657, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a handwriting recognition and automatic character input method, and more particularly, to an apparatus for allowing a user to handwrite desired information in a defined area on a touch screen and automatically recognizing the information, and a method thereof.

2. Description of the Related Art

Mobile terminals include enhanced features along with the development of all related technologies, including a wired/wireless communication technology, a multimedia technology, a technology for manufacturing hardware such as Central Processing Units (CPUs) and memories, and a power charging technology. Because the conventional mobile terminals have been used mainly for calls, users have felt little inconvenience even though the terminals have only numeric keypad buttons corresponding to phone numbers. However, owing to the increasingly widespread use of text messages, users may be inconvenienced by having to input various types of languages and characters.

Due to the development of mobile terminal-related technology, the existing products such as Personal Digital Assistants (PDAs) and laptop computers, and also many new-concept products including smart phones, Netbooks, Mobile Internet Devices (MIDs) and Ultra Mobile PCs (UMPCs) have been launched. Thanks to the advances in such technologies, it is possible to run a variety of applications in the mobile terminals, which requires a quick and convenient character input method.

The current representative character input methods include a character input method using physical keypad buttons, a character input method using a virtual keypad on a touch screen, and a character input method of recognizing information handwritten on a touch screen. The three different character input methods will be described in detail below.

FIG. 1illustrates the conventional character input method using physical keypad buttons.

Referring toFIG. 1, a screen for inputting text messages by a user can be displayed on an information display area101. The mobile terminal includes a key button area103with multiple key buttons capable of inputting information, the information display area101for outputting a variety of information such as input characters or numbers and special characters, and multiple menu key buttons105and107. A function capable of selecting Hangul, English, numbers and special characters may be included not only in a menu key button but also in a preset button, and the user can input desired characters by pressing associated keys with characters printed on them in the key button area103. The user can compose desired text messages using the above structures.

FIG. 2illustrates the conventional character input method using a virtual keypad on a touch screen.

Referring toFIG. 2, the touch screen can display a particular screen or an input screen with a virtual keypad by user input. A message input screen displayed on a touch screen201includes a key button area203with multiple key buttons capable of inputting information, a special key area205with multiple key buttons capable of selecting Hangul, English, numbers and special characters, an information display area207for outputting a variety of information such as characters or numbers and special characters being input by touches, and multiple menu key buttons209and211.

In the case of the message input screen shown inFIG. 2, the same environment as the environment of composing messages using the physical keypad buttons shown inFIG. 1may be implemented on the touch screen. Hence, the user can compose messages in the same way as the method of composing messages using the physical keypad buttons, with use of the key button area203, the special key area205and the information display area207, all of which are displayed on the touch screen201.

FIG. 3illustrates the conventional character input method using handwriting recognition on a touch screen.

Referring toFIG. 3, a touch screen301can display a particular screen by user input, i.e., can display an input screen different from the input screen with a virtual keypad shown inFIG. 2. A message input screen displayed on the touch screen301includes special key areas303with multiple key buttons capable of selecting Hangul, English, numbers and special characters, a handwriting recognition area305for directly inputting information using a finger or a stylus pen, an information display area307for outputting a variety of information such as characters or numbers and special characters being input by touch, and multiple menu key buttons309and311.

In the message input screen shown inFIG. 3, the handwriting recognition area305includes three single-recognition areas for recognizing one character or number and special character at a time, and user desired information is displayed on the information display area307in the order that the information is input by an input tool, e.g. a finger or a stylus pen. To switch from Hangul to English, or from Hangul to other characters or numbers and special characters, the user may choose a predefined button in the special key areas303and then enter desired characters. Thus, the user may compose messages as if writing on a notebook by hand, using the information display area307, the menu key buttons309and311, and the handwriting recognition area305displayed on the touch screen301.

However, in the case of the character input method using physical keypad buttons, to change specific settings of the mobile terminal or to set application information through character entry, the user must navigate to a pertinent input window by pressing particular menu or search buttons. Due to the limited number of keypad buttons, multiple characters are assigned to each button even for the same language to allow the user to enter various characters, so the user must enter the buttons selectively or in combination. This character input method inconveniences users who want fast text input.

The character input method using a virtual keypad on the touch screen also suffers from space limitations similar to those of the character input method using the physical keypad buttons, since the virtual keypad must be placed in the touch screen. This character input method is not so different from the character input method using physical keypad buttons in terms of the inconvenience to the user. In addition, to change a type of characters (numbers, uppercase English, lowercase English, Hangul, special characters, etc.) in the input window, the user needs to press particular keys for the character type change, which inevitably decreases the input speed.

Compared with the character input method using keypad buttons, the character input method using handwriting recognition on the touch screen is advantageous in that it can input characters by recognizing patterns of handwriting the user has entered without using keypad buttons, contributing to saving the keypad space. However, this method also needs additional setting tasks to change the character type, and in order to correct some of the input information, the user must choose the information to be corrected on the touch screen, delete the selected information, and then input the desired information.

SUMMARY OF THE INVENTION

An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to resolve the difficulties a user may suffer when entering characters in a mobile terminal.

Another aspect of the present invention is to provide an apparatus and method for inputting characters by allowing a user to directly handwrite the characters in a desired input field using an input tool, for example a stylus pen, without complex moving and/or setting processes.

In accordance with one aspect of the present invention, there is provided a character input method using a touch screen, in which one or more areas requiring user input is defined in the touch screen, pre-recognized information is defined for each of the defined areas, character information is received by a user in one or more user desired areas among the defined areas, the character information is recognized using a character recognizer, and the recognized character information is updated in the desired areas.

In accordance with another aspect of the present invention, there is provided a character input apparatus using a touch screen, in which the touch screen receives character information desired by a user and outputs the character information, a communication unit exchanges call-related voice signals and multimedia data with other mobile terminals over a mobile communication network, a controller receives the character information from the touch screen, recognizes the character information, and provides the recognized character information to the touch screen, and a storage unit stores one or more character recognizers for recognizing the character information received from the touch screen.

In accordance with a further another aspect of the present invention, there is provided a character input method using a touch screen, in which one or more areas requiring user input is displayed on the touch screen, character information is received from a user through defined areas, the received character information is recognized based on pre-recognized information predetermined for each of the defined areas, and the recognized character information is displayed on the defined areas.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings. The embodiments described herein and structures shown in the drawings are merely illustrative and do not cover every technical spirit of the invention. Therefore, it will be understood that various modifications which can substitute for the embodiments can be made at the time of filing the present application.

FIG. 4illustrates an internal structure of a mobile terminal with a touch screen according to an embodiment of the present invention. The mobile terminal includes a touch screen401, a communication unit403, a controller405, and a storage unit407.

Referring toFIG. 4, the touch screen401is used to receive information and/or control commands and transmit the received information and/or control commands to the controller405through user input. The touch screen401may also receive user input information from the controller405and display the received input information.

As mentioned above, the touch screen401may include input areas for receiving handwritten information that the user has entered in a touch manner using an input tool, e.g. a finger or a stylus pen, and output areas for displaying patterns or recognized results (or recognized characters) of the received handwritten information. The input areas and the output areas are provided on the touch screen401, and can overlap each other.

The communication unit403exchanges call-related voice signals and multimedia data with other mobile terminals over the mobile communication network, and provides the information to the controller405. The communication unit403may also receive information to be transmitted to other terminals from the controller405, and transmit the information to the mobile communication network.

The controller405receives desired information from the user, and displays it on the touch screen401. To be more specific, the controller405receives handwritten information from the input areas on the touch screen401, selects a proper handwritten-character recognizer, recognizes the user handwritten information using the selected handwritten-character recognizer, and then displays the recognized results on the output areas of the touch screen401.

The storage unit407includes (or stores) one or more handwritten-character recognizers for recognizing information entered through the touch screen401. In addition, the storage unit407may store an Operating System (OS) needed to drive the mobile terminal, and may also store various types of images and icons. Also, the storage unit407may store preset gestures. In this regard, if the user handwrites characters corresponding to user preset gestures, the controller405receives the associated results from the storage unit407and displays them on the touch screen401.

A process of recognizing user handwritten characters and automatically inputting the recognized characters using the aforementioned block diagram will be described with reference to the following flowchart.

FIG. 5illustrates a process of inputting and outputting information using a touch screen in a mobile terminal according to an embodiment of the present invention.

Referring toFIG. 5, a controller determines in step501whether entry of new information or correction of old information is required, and if so, the controller runs a pertinent application. In step503, the controller defines the number of areas requiring user input in the application. For example, to simply correct the current time, it is possible to separate an hour displaying area and a minute displaying area, with the current time displayed on the touch screen. In this case, the entire area is divided into two areas. A process of defining the number of areas may be determined differently depending on the type or use environment of the application.

If the number of areas requiring user input is defined, the controller defines pre-recognized information for each of the defined areas in step505. The pre-recognized information associated with each area includes information about a location occupied by the area on the touch screen, and information about a character recognizer that is used for the area and recognizes user handwriting patterns. The area-specific character recognizer information is information linked to a handwritten character recognizer for recognizing handwriting patterns in the pertinent input area. For example, in the case of entering a phone number, since the characters to be recognized are limited to numbers, only a low-capacity, high-performance handwritten-character recognizer capable of recognizing only numbers may be used without the need to use a general-purpose handwritten-character recognizer capable of recognizing all types of characters, including Hangul, English, and Chinese characters. In this manner, in many cases, different types of characters may be entered depending on the features of the areas. Therefore, if a proper handwritten-character recognizer is used for each area, the accuracy of handwritten-character recognition can be increased.

In step507, the controller receives user desired characters through input areas on the touch screen, for the respective areas. Regarding an input method, if the user handwrites characters in pertinent areas on the touch screen using a finger or a stylus pen, the controller receives a series of handwritten coordinate data, or handwriting patterns, from the input areas on the touch screen. In step509, the controller recognizes the received information using a character recognizer. Since different character recognizes are defined for the respective areas, the controller recognizes the input handwriting patterns without the process of selecting a character recognizer. The recognized characters are updated in their output areas on the touch screen in step511. If characters are already displayed in the user desired areas, new characters may be pre-displayed in the associated output areas. In the present invention, because the input areas and the output areas are provided overlapping with each other, old characters and new characters may be different in color or shading level to distinguishing the different characters.

If a predetermined time has elapsed after the user handwriting is input, the controller determines the midpoint of the handwritten coordinate data, and compares the midpoint with location information of each area to determine to which input area the input action corresponds. The user handwriting patterns are recognized by the character recognizer linked to the input areas where the input action has occurred, and the recognized characters are displayed on the output areas of the touch screen, replacing the old input information. In this process, since the old characters are updated (or replaced) with the new characters by simply inputting the new characters, the user does not need to delete the old input characters.

A process of updating characters based on the above flowchart will be described with reference to the following drawings.

FIG. 6illustrates an example of displaying pre-entered information and dividing input areas according to an embodiment of the present invention. While an alarm setting application is considered inFIG. 6, the present invention may be applied to other applications.

Referring toFIG. 6, the touch screen is divided into five input areas: a Year area, a Month area, a Date area, an Hour area, and a Minute area. Although the areas are partitioned by dotted lines in the drawing, the dotted lines can be displayed or removed depending on user choice. If the five input areas are defined, pre-recognized information is defined for each of the areas. Since the alarm setting application needs only a character recognizer for recognizing only the numbers, all of the five input areas have the same character recognizer.

FIGS. 7A to 8Billustrate updating areas requiring user input and correction according to an embodiment of the present invention.FIGS. 7A and 7Billustrate updating a character by directly handwriting a different character in a pertinent area, andFIGS. 8A and 8Billustrate updating a character by handwriting a preset gesture.

Referring toFIGS. 7A and 7B, if a user wants to correct an Hour-related character, the user handwrites a character “9” in the area on which a character “7” was originally displayed, as shown inFIG. 7A. If the handwritten character is provided to the controller through an input area associated with the area, the character recognizer linked to the area recognizes the handwritten character “9.” The handwritten character “9” is displayed in a different color on the old character “7,” and the Hour data is updated from “7” to “9” upon user input, as shown inFIG. 7B. Depending on setting of the update process, the Hour data may be automatically updated upon recognition of the handwritten character, without the user input.

Referring toFIGS. 8A and 8B, if a user wants to correct a Minute-related character, the user handwrites a preset simple gesture in the area on which characters “27” were originally displayed, as shown inFIG. 8A. The handwritten gesture is provided to the controller through an input area associated with the area, and the controller analyzes a preset gesture pattern in the area, and updates the old characters with an output value corresponding to the analyzed gesture pattern as shown inFIG. 8B. In an embodiment of the present invention, if a horizontal line is handwritten, the controller performs a gesture of inputting an initial value.

As is apparent from the foregoing description, according to embodiments of the present invention, a touch screen is divided into areas requiring user input, and input areas and output areas can overlap with each other in the respective areas. Thus, the user may directly handwrite characters only in the required areas without using a user interface requiring complex and troublesome input processes, thereby ensuring an intuitive input method.

In addition, pre-recognized environmental information is defined for each area, thus eliminating the need to change character type setting, and character recognizers specific to input areas are pre-selected, thereby improving recognition performance.

According to the present invention, the user can directly handwrite characters in required input areas without the various and troublesome input processes including moving and character type changing provided as a user interface to input characters in input areas requiring user input or correction, thus ensuring an intuitive and convenient character input method and a high character input speed.