Electrostatic capacitance-type sensor-equipped display device and method of driving the same

1. An electrostatic capacitance-type sensor-equipped display device comprising:

a display panel with a display surface which displays an image; and

an electrostatic capacitance-type sensor provided on the display panel,

the electrostatic capacitance-type sensor including:

a plurality of detection electrodes disposed in a matrix that includes M rows and N columns, where M is greater than 1 and N is greater than 1,

each of the detection electrodes being arranged so as to not be in physical contact with each other, being mutually electrically independently provided from each other above the display surface and being configured to detect a variation in electrostatic capacitance; and

a plurality of lead lines provided above the display surface, the lead lines being M×N in number, the lead lines being respectively connected to the detection electrodes in a one-to-one correspondence, and formed of a metal,

wherein

each of the detection electrodes is formed of an aggregate of a transparent electrode which is formed of a transparent, electrically conductive material, and a plurality of branch lines which are branched from each of the lead lines,

the branch lines are located immediately below the transparent electrode, and

each of the branch lines is in contact with the transparent electrode.

2. The electrostatic capacitance-type sensor-equipped display device of claim 1 , further comprising:

a control module connected to the lead lines, wherein

the control module is configured to write a write signal in each of the detection electrodes, to read a read signal, which is indicative of a variation in electrostatic capacitance occurring in each of the detection electrodes in which the write signal has been written, and to determine input position information, based on the variation in electrostatic capacitance.

3. The electrostatic capacitance-type sensor-equipped display device of claim 2 , further comprising:

a plurality of detectors; and a multiplexer connected between the electrostatic capacitance-type sensor and the detectors, wherein

the multiplexer is configured to distributively write the write signal, which is transmitted from the detectors, in the detection electrodes, and to transmit the read signal, which is selectively read from the detection electrodes, to the detectors.

4. The electrostatic capacitance-type sensor-equipped display device of claim 1 , wherein

the electrostatic capacitance-type sensor further includes a plurality of dummy lines formed above the display surface of the display panel and formed of a metal.

5. The electrostatic capacitance-type sensor-equipped display device of claim 4 , wherein

a first pitch, a second pitch and a third pitch are identical,

the first pitch is a pitch of the lead lines,

the second pitch is a pitch of the dummy lines, and

the third pitch is a pitch of a lead line and a dummy line neighboring each other, among the lead lines and the dummy lines.

6. The electrostatic capacitance-type sensor-equipped display device of claim 4 , wherein

the display panel further includes a plurality of pixels disposed in a matrix,

each of a first pitch, a second pitch and a third pitch is an integer-number of times of a pixel pitch,

the first pitch is a pitch of the lead lines,

the second pitch is a pitch of the dummy lines, and

the third pitch is a pitch of a lead line and a dummy line neighboring each other, among the lead lines and the dummy lines.

7. The electrostatic capacitance-type sensor-equipped display device of claim 1 , wherein

the electrostatic capacitance-type sensor further includes a plurality of dummy electrodes provided above the display surface of the display panel, located between a plurality of the transparent electrodes of the detection electrodes, and formed of a transparent, electrically conductive material.

8. A method of driving an electrostatic capacitance-type sensor-equipped display device comprising a display panel and an electrostatic capacitance-type sensor provided on the display panel, the display panel including a first substrate, a second substrate which includes a display surface for displaying an image and is disposed opposite to the first substrate with a gap, a plurality of pixels, and a common electrode provided on the first substrate or the second substrate and shared by the pixels, each of the pixels including a pixel switching element formed on the first substrate and connected to a gate line and a source line, and a pixel electrode formed on the first substrate and connected to the pixel switching element, and the electrostatic capacitance-type sensor including a plurality of detection electrodes disposed in a matrix, the detection electrodes being arranged so as to not be in physical contact with each other, being mutually electrically independently provided above the display surface, being opposed to the common electrode, and being configured to detect a variation in electrostatic capacitance, and a plurality of lead lines provided above the display surface, connected to the detection electrodes in a one-to-one correspondence, and formed of a metal, the method comprising:

delivering a control signal to the gate line and a video signal to the source line, in a display operation period, thereby driving the display panel,

stopping an input of the control signal and the video signal to the display panel, and driving the electrostatic capacitance-type sensor, in an input position information detection period that does not overlap the display operation period; and

writing a potential adjustment signal, which has the same waveform as a write signal which is written in each of the detection electrodes of the electrostatic capacitance-type sensor, in the common electrode in synchronism with the write signal, in the input position information detection period.

9. The method of claim 8 , wherein the common electrode includes a plurality of divisional electrodes which are divided from each other, and

the potential adjustment signal is written, only in a divisional electrode which is opposed to the detection electrode in which the write signal is written, among the plurality of divisional electrodes, during the input position information detection period.

10. The method of claim 9 , wherein

the potential adjustment signal is written, not only in the divisional electrode, but also in another divisional electrode neighboring one side of the divisional electrode or in two other divisional electrodes neighboring both sides of the divisional electrode, during the input position information detection period.

11. The method of claim 8 , wherein,

during the input position information detection period, the potential adjustment signal is further written in the source line.

12. The method of claim 8 , wherein the display panel further includes a first control switching element which is formed on the first substrate, is connected to the gate line, and permits, by being turned on, write of the control signal in the gate line, and a second control switching element which is formed on the first substrate, is connected to the source line, and permits, by being turned on, write of the video signal in the source line, and

the first control switching element and the second control switching element are turned off during the input position information detection period, thereby switching the gate line and the source line to an electrically floating state.

13. The method of claim 8 , wherein the common electrode includes a plurality of divisional electrodes extending in a first direction and arranged at intervals in a second direction crossing the first direction,

switching is effected to either a self-capacitive sensing method or a mutual-capacitive sensing method, and input position information is determined based on the variation in electrostatic capacitance,

a write signal is written in each of the detection electrodes, and a read signal, which is indicative of a variation in electrostatic capacitance occurring in each of the detection electrodes in which the write signal has been written, is read, when the input position information is determined by the self-capacitive sensing method, and

a write signal is written in each of the divisional electrodes, and a read signal, which is indicative of a variation in electrostatic capacitance occurring in each of the detection electrodes, is read, when the input position information is determined by the mutual-capacitive sensing method.

14. The method of claim 13 , wherein

the detection electrodes form a plurality of detection electrode groups each including a plurality of detection electrodes arranged in the second direction, the detection electrode groups being arranged in the first direction, and

after the read signal has been read by the mutual-capacitive sensing method, a plurality of the read signals, which have been read from each of the detection electrode groups, are bundled into one signal.

15. The electrostatic capacitance-type sensor-equipped display device of claim 1 , wherein each of the detection electrodes is quadrangular.

16. The electrostatic capacitance-type sensor-equipped display device of claim 1 , wherein

the branch lines are in contact with the transparent electrode in a whole region in which the branch lines are opposed to the transparent electrode.

17. The electrostatic capacitance-type sensor-equipped display device of claim 1 , wherein the branch lines have a shape of wavy lines.

18. An electrostatic capacitance-type sensor-equipped display device comprising:

a display panel with a display surface which displays an image; and

an electrostatic capacitance-type sensor provided on the display panel,

the electrostatic capacitance-type sensor including:

a plurality of detection electrodes disposed in a matrix,

each of the detection electrodes arranged so as to not be in physical contact with each other, mutually electrically independently provided from each other above the display surface, and configured to detect a variation in electrostatic capacitance; and

a plurality of lead lines provided above the display surface, respectively connected to the detection electrodes in a one-to-one correspondence, and formed of a metal,

wherein

each of the detection electrodes is formed of an aggregate of a transparent electrode which is formed of a transparent, electrically conductive material, and a metal line which is electrically connected to each of the lead lines,

the metal line is located immediately below the transparent electrode,

the metal line extends from one end portion of the transparent electrode to another end portion of the transparent electrode, in a region which is opposed to the transparent electrode, and

the metal line is in contact with the transparent electrode in a whole region in which the metal line is opposed to the transparent electrode.

19. The electrostatic capacitance-type sensor-equipped display device of claim 18 , further comprising:

a control module connected to the lead lines,

wherein

the control module is configured to write a write signal in each of the detection electrodes, to read a read signal, which is indicative of a variation in electrostatic capacitance occurring in each of the detection electrodes in which the write signal has been written, and to determine input position information, based on the variation in electrostatic capacitance.

20. The electrostatic capacitance-type sensor-equipped display device of claim 18 , wherein each of the detection electrodes is quadrangular.