JP2008097220A - Character input device, character input method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To input characters without key operations for switching functions. <P>SOLUTION: A cellphone terminal 11 in which character input functions are switched according to the direction of inclination of a body detects the inclination using a camera 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for applying a rotation operation to a character input device body and changing the character input operation depending on the tilt direction of the body.

  A conventional character input method in a portable terminal device has a strict limit on the number of input keys. Therefore, in order to input a single kana character, an input method in which the same key is pressed a plurality of times is generally used.

  In addition, if a key operation is accidentally pressed, it is necessary to press a key other than the key assigned to input the character and press the same key more than once, which takes a lot of time and labor for input. There was an inconvenience.

  An example of a conventional character input method using tilt information of a portable terminal body is described in Patent Documents 1 and 2, for example. These technologies include a control unit that applies a rotation operation to the portable information device main body, detects acceleration associated with the tilt of the main body using an acceleration sensor, and displays information related to the input operation according to the tilt. Is.

Here, a plurality of input modes for changing the type of characters to be input are provided, an inclination angle detection unit for detecting the inclination angle of the own device, a storage unit for storing the inclination angle, and a character input operation by the operation unit After the inclination angle detected by the inclination angle detection unit is stored in the storage unit as the reference inclination angle, the inclination angle detected by the inclination angle detection unit changes, and this inclination angle and the reference inclination angle stored in the storage unit And a control unit that controls to switch the input mode when the inclination angle returns to the reference inclination angle after the relative angle becomes larger than a predetermined angle, thereby reducing the speed of character input. In addition, a technique has been proposed in which an operation for switching the type of characters to be input can be easily performed, and such an operation can be performed with only one hand (see, for example, Patent Document 3).
JP 2005-159470 A JP 2000-194893 A JP 2004-355229 A

  However, the prior art has the following problems. The first problem is that the user must always look at the display portion when inputting characters. The reason is that since the acceleration sensor reacts to all the operations applied to the terminal body, the user must always check the display portion for detecting the tilt information by mistake. This is a major obstacle when a user who is used to character input enters characters without checking the display unit.

  The second problem is that a special device such as an acceleration sensor is required.

  The present invention has been made to solve the above-described problems. The purpose is to input characters without performing key operations for switching functions.

In order to solve the above problem, the present invention is a character input device in which a character input function is switched according to the direction of inclination of the main body,
Provided is a character input device that detects tilt using a camera mechanism.

The present invention also includes a step of detecting an inclination using the camera mechanism of the character input device body,
Switching the character input function according to the direction of tilt of the main body,
A character input method having

  According to the present invention, it is possible to input characters without performing a key operation for switching functions.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure.

  In FIG. 1, a mobile phone terminal 11 as a character input device in the present embodiment includes a display device 12, a key input device unit 13, a CPU 14 (central processing unit; processor; data processing device) that operates by program control, and a camera 15. The memory 16 is configured.

  Each of these devices operates as follows. The display device 12 is an output device for displaying character input results and the like under the control of the CPU 14. The key input device unit 13 is an input device for inputting characters. The CPU 14 performs control of the display device 12, the key input device unit 13, the camera 15, and the memory 16, character conversion processing, and image processing. The camera 15 is attached to the side of the display device, and is used for photographing a user's face when using the terminal. The memory 16 is used for storing data relating to character input and data such as image estimation results.

  Next, the operation of the present embodiment will be described in detail with reference to the flowchart of FIG.

  First, an image used for tilt estimation is taken using a camera attached to the inside of the terminal (step 21). In addition, since the detection of the tilt is realized using a camera, only existing functions / parts do not cost.

  Next, feature points such as eyes and nose are extracted from the photographed image, and it is estimated whether or not a face region exists in the photographed image based on the information on the arrangement relation of the feature points and the appearance of the image (steps 22 and 23). ).

  If the face area does not exist in the image, the user has not confirmed the display unit, so it is determined that the apparatus body is not intentionally tilted, and tilt estimation is not performed. Instead, “no tilt” is stored as tilt information in the memory (step 24). By recognizing whether the user is looking at the display unit in this way, it is possible to prevent erroneous tilt detection.

  If there is a face area in the image, the inclination of the terminal body is estimated from the image information (step 25), and the estimation result is stored in the memory (step 26).

  After the inclination estimation is completed, the stored inclination information is checked (step 27), and the estimated inclination direction (or the corresponding function is in operation) is output to the display unit, and the result is displayed to the user. (Step 28).

  Subsequently, it is checked whether or not the key is pressed (step 29). If the key is pressed, the process assigned according to the tilt information is started (step 210). Finally, it is confirmed whether or not there is an end request. These processes are repeated until an end request is received.

  An example of tilt estimation using image information is shown in the flowchart of FIG.

  First, feature points are extracted from the image at time t (step 31).

  Next, the optical flow (velocity field at each point on the screen) is estimated from the feature point information at time t and the feature point information detected up to time t-1 using various methods such as gradient method and block matching method. (Step 32).

  Then, threshold processing is performed on the estimated size of the optical flow, and it is determined whether the terminal body has moved since the previous time (step 33).

  If there is no movement, it is determined that there is no rotation operation on the terminal body, and the inclination is the same as the previous time (step 34).

  In addition, when there is movement, for example, when the terminal body is rotated in the left direction as shown in FIG. 4, the optical flow of the entire image is in the right direction. Therefore, by examining which direction the optical flow of the entire image is directed, it is estimated to which direction the rotation operation has been performed (step 35).

  Further, in order to reduce the influence of the estimation error, the estimation result is verified using the pre-registered image at each inclination. (Step 36). For example, as shown in FIG. 5, an image when rotated in the left direction in advance and an image when there is no rotation are taken in advance, and the positions of feature points between the image at time t and the image at each inclination are determined. By comparing and calculating the error, the estimation result is verified. If the difference between the estimated inclination and the registered image corresponding to the inclination is larger than a certain threshold, it is assumed that there is no inclination from the viewpoint of fail-safe.

  Finally, the operation of this embodiment will be described using a specific example. For example, it is assumed that the terminal body is assigned to perform kana input when rotation is not applied and the alphabetical input is performed when left rotation operation is applied to the terminal body. At this time, when “Aka ad” is input without using the present embodiment, as shown in FIG. 6, the A line key, the line key, the character input mode change key, the a key, and the d key are totaled 5 times. Must be entered. On the other hand, when this embodiment is used, it is possible to reduce the number of times the key is input because it is sufficient to input four times in total: the a-row key, the row key, the left rotation, the a-key, and the d-key. Become.

  According to the above-described embodiment, since characters can be input with a small number of key presses, the input speed can be improved. The reason is that by inputting a plurality of functions to one key using the tilt information, it is possible to input characters without performing a key operation for performing function switching.

  Moreover, it is realizable only with the general apparatus currently mounted in the mobile telephone terminal, without using special apparatuses, such as an acceleration sensor. The reason is that only an image taken from a camera installed inside is used for detecting the tilt.

  Each of the above-described embodiments is a preferred embodiment of the present invention, and various modifications can be made without departing from the scope of the present invention. For example, a process for realizing the function of the device may be performed by causing the device to read and execute a program for realizing the function of the character input device. Further, the program is transmitted to another computer system by a transmission wave via a computer-readable recording medium such as a CD-ROM or a magneto-optical disk, or via a transmission medium such as the Internet or a telephone line. Also good.

  In each of the above-described embodiments, the configuration in which the character input device is realized as one computer system has been described. However, it is needless to say that the embodiments can be applied to a configuration in which a plurality of devices are added for each function. .

  Further, the present invention can be applied to applications such as a character input device and a program for controlling them in a portable information device such as a mobile phone terminal or a PDA.

It is a figure which shows the structure of the mobile telephone terminal in embodiment of this invention. It is a flowchart which shows the processing operation in embodiment of this invention. It is a flowchart which shows the processing operation | movement of the inclination estimation using the image information in embodiment of this invention. It is a figure which shows the case where rotation of the left direction is added with respect to the terminal main body in embodiment of this invention. It is a figure which shows an example in the case of calculating the error in embodiment of this invention. It is a figure which shows the specific example in embodiment of this invention.

Explanation of symbols

11 Mobile phone terminal 12 Display device 13 Key input device section 14 CPU
15 Camera 16 Memory

Claims (6)

A character input device whose character input function is switched depending on the direction of tilt of the main body,
A character input device that detects tilt using a camera mechanism.   The character input device according to claim 1, wherein erroneous detection of tilt is prevented by recognizing whether or not the display unit is viewed based on a user's face image. Detecting the tilt using the camera mechanism of the character input device body;
Switching the character input function according to the direction of tilt of the main body,
The character input method characterized by having.   The character input method according to claim 3, further comprising a step of preventing erroneous tilt detection by recognizing whether or not the display unit is viewed based on a face image of the user.   A program for causing a computer to realize the function according to claim 1.   A program for causing a computer to realize the function according to claim 2.

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