Contact detecting device, display device, and contact detecting method

A contact detecting device comprising:

• n driving electrodes that are arranged in a scanning direction at a fixed pitch;
• plural detection electrodes, between which and the respective n driving electrodes capacitors are formed;
• a detection drive scanning unit that performs driving operation for simultaneously AC-drives m (2≦m<n) driving electrodes continuous in the scanning direction and repeats, with size in the scanning direction of the driving electrodes smaller in number than m set as an amount of shift for one time, shift operation for changing a combination of the simultaneously-driven m driving electrodes in the scanning direction;
• and
• plural detection circuits that are connected to the plural detection electrodes in a one-to-one relation and compare potentials of the detection electrodes corresponding thereto with a predetermined threshold every time the detection drive scanning unit performs the shift operation.

A display device comprising:

• plural pixel electrodes that are provided for the respective pixels and planarly arranged in a matrix;
• n counter electrodes that are planarly arranged to be opposed to the pixel electrodes, have pitch length natural number times as large as pitch length of an array of the pixel electrodes in a scanning direction, which is one arranging direction of the pixel electrodes, and are arranged at equal intervals in the scanning direction;
• plural detection electrodes, between which and the respective n counter electrodes capacitors are formed;
• a display function layer that shows an image display function according to signal voltage applied between the pixel electrodes and the counter electrodes opposed to each other;
• a detection drive scanning unit that selects continuous m (2≦m<n) counter electrodes out of the n counter electrodes, simultaneously AC-drives the selected m counter electrodes, and repeats shift operation for changing selection targets of the m counter electrodes in the scanning direction such that one or more driving electrodes common before and after the shift operation performed each time are included in the selection targets;
• and
• plural detection circuits that are connected to the plural detection electrodes in a one-to-one relation and compare potentials of the detection electrodes corresponding thereto with a predetermined threshold every time the detection drive scanning unit performs the shift operation.

A display device comprising:

• plural pixel electrodes that are provided for the respective pixels and planarly arranged in a matrix;
• n counter electrodes that are planarly arranged to be opposed to the pixel electrodes, have pitch length natural number times as large as pitch length of an array of the pixel electrodes in a scanning direction, which is one arranging direction of the pixel electrodes, and are arranged at equal intervals in the scanning direction;
• plural detection electrodes, between which and the respective n counter electrodes capacitors are formed;
• a display function layer that shows an image display function according to signal voltage applied between the pixel electrodes and the counter electrodes opposed to each other;
• a detection drive scanning unit that performs driving operation for simultaneously AC-driving m (2≦m<n) counter electrodes continuous in the scanning direction and repeats, with size in the scanning direction of the counter electrodes smaller in number than m set as an amount of shift for one time, shift operation for changing a combination of the simultaneously-driven m counter electrodes in the scanning direction;
• and
• plural detection circuits that are connected to the plural detection electrodes in a one-to-one relation and compare potentials of the detection electrodes corresponding thereto with a predetermined threshold every time the detection drive scanning unit performs the shift operation.

A contact detecting method comprising the steps of:

• selecting continuous m (2≦m<n) driving electrodes out of n driving electrodes arranged in a scanning direction;
• simultaneously AC-driving the selected m driving electrodes and repeating shift operation for changing selection targets of the m driving electrodes in the scanning direction such that one or more driving electrodes common before and after the shift operation performed each time are included in the selection targets;
• comparing potentials of the respective driving electrodes with a predetermined threshold every time the shift operation is performed;
• and
• determining, from an obtained comparison result, at least one of position and size of a changing area in which applied voltage of capacitors formed between the n driving electrodes and the respective detection electrodes changes because of influence of an external capacity.

A contact detecting method comprising the steps of:

• performing driving operation for simultaneously AC-driving continuous m (2≦m<n) driving electrodes out of n driving electrodes arranged in the scanning direction and repeating, with size in the scanning direction of the driving electrodes smaller in number than m set as an amount of shift for one time, shift operation for changing a combination of the simultaneously-driven m driving electrodes in the scanning direction;
• comparing potentials of the respective driving electrodes with a predetermined threshold every time the shift operation is performed;
• and
• determining, from an obtained comparison result, at least one of position and size of a changing area in which applied voltage of capacitors formed between the n driving electrodes and the respective detection electrodes changes because of influence of an external capacity.