Electronic device, control method, and integrated circuit

1. An electronic device comprising:

a detector configured to detect a region touched on a touch panel;

a memory; and

a processor coupled to the memory, configured to:

approximate, to a first ellipse, a first touched region detected by the detector at a first time, the first ellipse is approximated based on first coordinates of first grids included in the first touched region;

approximate, to a second ellipse, a second touched region detected by the detector at a second time, the second ellipse is approximated based on second coordinates of second grids included in the second touched region,

calculate a first angle formed between a first major axis of the first ellipse and a reference axis of the touch panel;

calculate a first reference point of the first ellipse based on a first center of gravity of the first ellipse;

calculate a second angle formed between a second major axis of the second ellipse and the reference axis of the touch panel;

calculate a second reference point of the second ellipse based on a second center of gravity of the second ellipse;

determine an angle difference between the first angle and the second angle;

determine a location difference between the first reference point and the second reference point;

calculate an area of the second touched region;

determine a touch state of the touch panel based on the area; and

control to enlarge or reduce an image displayed on the touch panel based on the determined touch state, the angle difference, and the location difference, wherein a rate of the enlarging or reducing corresponds to the angle difference and the location difference.

2. A control method comprising:

detecting a region touched on a touch panel;

approximating, to a first ellipse, a first touched region detected at a first time, the first ellipse is approximated based on first coordinates of first grids included in the first touched region;

approximating, to a second ellipse, a second touched region detected at a second time, the second ellipse is approximated based on second coordinates od second grids included in the second touched region;

calculating a first angle formed between a first major axis of the first ellipse and a reference axis of the touch panel;

calculating a first reference point of the first ellipse based on a first center of gravity of the first ellipse;

calculating a second angle formed between a second major axis of the second ellipse and the reference axis of the touch panel;

calculating a second reference point of the second ellipse based on a second center of gravity of the second ellipse;

determining an angle difference between the first angle and the second angle;

determining a location difference between the first reference point and the second reference point;

calculating an area of the second touched region;

determining a touch state of the touch panel based on the area; and

controlling to enlarge or reduce an image displayed on the touch panel based on the determined touch state, the angle difference, and the location difference, wherein a rate of the enlarging or reducing corresponds to the angle difference and the location difference.

3. An integrated circuit comprising:

a detector configured to detect a region touched on a touch panel;

a calculator configured to:

approximate, to a first ellipse, a first touched region detected by the detector at a first time, the first ellipse is approximated based on first coordinates of first grids included in the first touched region;

approximate, to a second ellipse, a second touched region detected by the detector at a second time, the second ellipse is approximated based on second coordinates of second grids included in the second touched region;

calculate a first angle formed between a first major axis of the first ellipse and a reference axis of the touch panel;

calculate a first reference point of the first ellipse based on a first center of gravity of the first ellipse;

calculate a second angle formed between a second major axis of the second ellipse and the reference axis of the touch panel;

calculate a second reference point of the second ellipse based on a second center of gravity of the second ellipse;

calculate an angle difference between the first angle and the second angle;

calculate an area of the second touched region; and

output the calculated results; and

a processor controller configured to:

determine a touch state of the touch panel based on the area; and

control to enlarge or reduce an image displayed on the touch panel based on the determined touch state, the angle difference, and the location difference, wherein a rate of the enlarging or reducing corresponds to the angle difference and the location difference.

4. The electronic device according to claim 1 ,

wherein the processor is configured to determine at least one of a first state in which a large region is touched, a second state in which a small region is touched, and an untouched state as the touch state of the touch panel.

5. The electronic device according to claim 4 ,

wherein the processor is configured to determine the first state when the area is larger than a first determination threshold, the second state when the area is equal to or smaller than the first determination threshold and larger than a second determination threshold, and the untouched state when the area is equal to or smaller than the second determination threshold.

6. The electronic device according to claim 4 , wherein the processor is configured to determine to control to enlarge or reduce the image in response to determining that the touch state is the first touch state.