DESCRIPTION

MOBILE TERMINAL AND CONTROL METHOD THEREOF

Technical Field

[0001]
The present invention relates to a mobile terminal and a control method thereof, and more particularly, to a mobile terminal including a touch panel, and a control method thereof.

Background Art

[0002]
In recent years, a touch panel that senses a touch of a fingertip or a pen to perform an input operation is used as a UI (User Interface) of a mobile terminal. As systems for sensing a touch, a resistive system, an ultrasonic wave system, a capacitive system, and the like are proposed.

[0003]
Patent Literature 1 discloses a technique in which a contact area of a pen on a touch panel is detected and switching between an input mode and a delete mode is made according to the detected contact area. Specifically, the input mode is enabled when the touch panel is touched by a narrow pen tip, and the delete mode is enabled when the touch panel is touched by a large pen tip.

[0004]
Patent Literature 2 discloses a technique in which when a contact area on a touch panel is smaller than a predetermined value, it is determined that an input has been made by a pen, and when the contact area is equal to or larger than the predetermined value, it is determined that an input has been made by a finger.

[0005]
Meanwhile, Patent Literature 3 discloses a technique in which dot spacers are arranged at different pitches on a resistive touch panel. Specifically, on the touch panel, in a region where the dot spacers are arranged at a relatively long pitch, an input can be made by both a finger and a pen, and in a region where the dot spacers are arranged at a pitch smaller than the pitch, an input can be made only by a pen. Further, in a region where the arrangement pitch of the dot spacers is even smaller, both an input by a finger and an input by a pen are inhibited.

[0006]
On the other hand. Patent Literature 4 discloses a technique in which processing operations are correlated with a fingerprint pattern of a finger of a user or with a contact area pattern; the fingerprint pattern or the contact area pattern of the finger touching a touch panel is detected; and the processing operation allocated to the fingerprint pattern or the contact area pattern is executed.
Citation List Patent Literature

[0007]
[Patent Literature 1] Japanese Unexamined Patent Application
Publication No. 07-200133
[Patent Literature 2] Japanese Unexamined Patent Application
Publication No. 2008-108233
[Patent Literature 3] Japanese Unexamined Patent Application
Publication No. 2007-219737
[Patent Literature 4] Japanese Unexamined Patent Application
Publication No. 11-327727
Summary of Invention Technical Problem

[0008]
In the techniques disclosed in Patent Literatures 1 and 2, however, when a mobile terminal including a touch panel is gripped by a user, an unintended portion (for example, a finger pad, a palm, or the like of the user) touches the touch panel, which may lead to occurrence of the delete mode or an erroneous input as a finger input.

[0009]
Further, in the technique disclosed in Patent Literature 3, an unintended input by a finger or a pen can be inhibited by adjusting the arrangement pitch of the dot spacers. To achieve this, it is necessary to preliminarily determine the regions where the input is inhibited. However, it is difficult to predict the positions where an unintended input may be made and to determine the regions where the input is inhibited.

[0010]
Furthermore, in the technique disclosed in Patent Literature 4, the touch panel does not react to a touch of a non-registered fingerprint pattern or contact area pattern. For this reason, it is necessary to register all the fingerprint patterns or contact area patterns of fingers which may be used. This requires a troublesome operation for the user.

[0011]
The present invention has been made to solve the above-mentioned problems and has an object to provide a mobile terminal capable of preventing an unintended erroneous input to a touch panel, and a control method thereof.

Solution to Problem

[0012]
A mobile terminal according to an exemplary aspect of the present invention includes: a touch panel that receives an input through a touch of an object; contact area detection means for detecting a contact area of the object on the touch panel, when the object touches the touch panel; and input determination means for determining whether the input through the touch of the object on the touch panel is valid or not. The input determination means determines that the input through the touch of the object is invalid when the contact area detected by the contact area detection means is equal to or larger than a value corresponding to an upper limit of a contact area of a fingertip touching the touch panel.

[0013]
A mobile terminal control method according to another exemplary aspect of the present invention includes: detecting a contact area of an object on a touch panel that receives an input through a touch of the object, when the object touches the touch panel; and determining whether the input through the touch of the object on the touch panel is valid or not. The determination as to whether the input is valid or not includes determining whether the input through the touch of the object is valid or not when the contact area detected is equal to or larger than a value corresponding to an upper limit of a contact area of a fingertip touching the touch panel during a finger input.

Advantageous Effects of Invention

[0014]
According to the present invention, it is possible to provide a mobile terminal capable of preventing an unintended erroneous input to a touch panel, and a control method thereof.

Brief Description of Drawings

[0015]
Fig. 1 is a diagram showing a configuration example of a mobile terminal according to a first exemplary embodiment;

Fig. 2 is a diagram showing an example of use of the mobile terminal according to the first exemplary embodiment;

Fig. 3 is a flowchart showing an operation of the mobile terminal according to the first exemplary embodiment;

Fig. 4 is a diagram for explaining information notified to a control unit according to the first exemplary embodiment;

Fig. 5 is a diagram showing a configuration example of a mobile terminal according to a second exemplary embodiment;

Fig. 6 is a flowchart showing an operation of the mobile terminal according to the second exemplary embodiment;

Fig. 7 is a diagram showing a configuration example of a mobile terminal according to a third exemplary embodiment; and

Fig. 8 is a flowchart showing an operation of the mobile terminal according to the third exemplary embodiment.

Description of Embodiments

[0016]
First Exemplary Embodiment
Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Fig. 1 shows a configuration example of a mobile terminal 1 according to this exemplary embodiment. The mobile terminal 1 includes a control unit 10, an LCD (Liquid Crystal Display) 20, a touch panel 30, and a general-purpose application unit 40.

[0017]
The control unit 10 includes a display unit 101 and an input determination unit 102. The display unit 101 displays screen information sent from the general-purpose application unit 40 on the LCD 20. In this case, when an object touches the touch panel 30, the general-purpose application unit 40 acquires coordinate information on the touch panel 30 which is notified from the control unit 10. Then, the general-purpose application unit 40 executes event processing based on the acquired coordinate information, and sends the execution result of the event processing to the display unit 101 to thereby update screen information. Examples of the contents of the application include a browser and a mailer which are recent well-known typical applications.

[0018]
When an object touches the touch panel 30, the input determination unit 102 determines whether an input through a touch on the touch panel 30 is valid or not. Specifically, when the area of the object touching the touch panel 30 is equal to or larger than a value (hereinafter referred to as a first threshold) corresponding to an upper limit of a contact area of a fingertip touching the touch panel 30 during a finger input operation, it is determined that the input through a touch with the object is invalid. Note that the first threshold can be arbitrarily set by a user, and desirably indicates an area larger than a fingertip and smaller than a finger pad.

[0019]
The touch panel 30 includes a contact coordinate acquisition unit 301 and a contact area detection unit 302. The contact coordinate acquisition unit 301 acquires the coordinate of the object touching the touch panel 30. Specifically, when the user touches the touch panel 30 with a pen, a finger, or the like, the contact coordinate acquisition unit 301 acquires coordinate information of the contact point, and sends the coordinate information to the control unit 10. When the object touches the touch panel 30, the contact area detection unit 302 detects the contact area of the object on the touch panel 30.

[0020]
An example of use of the mobile terminal 1 will now be described with reference to Fig. 2. As shown in Fig. 2, the user of the mobile terminal 1 grips the mobile terminal 1 with one hand, and performs an input operation while touching the touch panel 30 with a pen 91 in the other hand (or a fingertip of the other hand). At this time, when the user grips the mobile terminal 1 with one hand, the touch panel 30 has a size that allows a part of the fingers of the hand gripping the mobile terminal to touch the touch panel 30. More specifically, in the case where the mobile terminal 1 in which the region of the touch panel 30 occupies 80 to 90% of the area of a surface 50, on which the touch panel 30 of the mobile terminal is provided, is gripped, fingers are more likely to touch the touch panel 30. Therefore, the effect of applying the present invention is significant. Fig. 2 shows a use state where a thumb 92 of the hand gripping the mobile terminal 1 touches the touch panel 30.

[0021]
Subsequently, an operation example of the mobile terminal 1 according to this exemplary embodiment will be described with reference to the flowchart shown in Fig. 3. First, the touch panel 30 detects a touch of an object (step SlOl). Then, the contact area detection unit 302 detects a contact area W of the object touching the touch panel 30 and sends information on the contact area W to the control unit 10 (step S102). At this time, the contact coordinate acquisition unit 301 also sends the coordinate information of the acquired object contact position to the control unit 10. The input determination unit 102 determines whether the received contact area W is larger than a first threshold Wa (step S103).

[0022]
When the contact area W is smaller than the first threshold Wa (WWa), the input determination unit 102 determines that the input through the touch of the object is invalid. Accordingly, the control unit 10 does not send, to the general-purpose application unit 40, the coordinate information of the touch when the contact area W is equal to or larger than the first threshold Wa. That is, the general-purpose application unit 40 executes no processing for the touch of the object on the touch panel 30.

[0024]
The above-mentioned operation of the touch panel 30 will be described in more detail with reference to an example of use shown in Fig. 2. Fig. 4 is a diagram showing the information notified from the touch panel 30 to the control unit 10 in the example of use shown in Fig. 2. In Fig. 4, as for a portion 93 touching the touch panel 30 with the pen 91, the contact coordinate acquisition unit 301 acquires a coordinate (xl, yl) of the portion 93 and sends the coordinate information to the control unit 10. At this time, the contact coordinate acquisition unit 301 acquires the central coordinate of the contact portion. Further, the contact area detection unit 302 detects a contact area Wl and sends the information on the contact area Wl to the control unit 10. Similarly, the touch panel 30 sends a coordinate (x2, y2) of a contact portion 94 touched by the thumb 92 and a contact area W2 to the control unit 10.

[0025]
The input determination unit 102 determines whether the contact areas Wl and W2 sent from the contact area detection unit 302 are equal to or larger than the first threshold Wa. Assume in this embodiment that WlWa), the input determination unit 102 determines that the input through the touch of the object is invalid.

[0033]
On the other hand, when the contact area W is smaller than the first threshold Wa (WWa), the input determination unit 102 determines that the input through the touch of the object is invalid.

[0040]
On the other hand, when the contact area W is smaller than the first threshold Wa (W