Touch panel and display device with a built-in touch panel
View Patent ↗Provided is a touch panel including: a plurality of scanning electrodes formed on a display panel; a plurality of detecting electrodes intersecting with the plurality of scanning electrodes, the plurality of detecting electrodes being formed on the display panel; a first unit for sequentially connecting a constant current source to each of the plurality of scanning electrodes for each one scanning period; and a second unit for detecting a touch position on the display panel based on a variation of a current detected at each of the plurality of detecting electrodes. One of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed on the display panel surface on a viewer side, and another of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed inside the display panel.
1. A touch panel, comprising:
a plurality of scanning electrodes;
a plurality of detecting electrodes intersecting with the plurality of scanning electrodes;
a detection signal source which sequentially connects a constant current source to each of the plurality of scanning electrodes for each one scanning period; and
a detection circuit which detects a touch position on the touch panel based on a variation of a current detected at each of the plurality of detecting electrodes;
wherein, even in a case where a new current passage occurs, the constant current source operates to generate a total current amount which is constant; and
wherein the detection circuit detects a touch position by detecting the detecting electrode to which an amount of current flowing is reduced due to the new current passage.
2. The touch panel according to claim 1 , wherein the plurality of scanning electrodes and the plurality of detecting electrodes are formed on different surfaces.
3. The touch panel according to claim 1 , wherein the plurality of scanning electrodes and the plurality of detecting electrodes are formed on different surfaces across an insulating member.
4. The touch panel according to claim 1 , wherein the plurality of scanning electrodes and the plurality of detecting electrodes each comprise a stripe-type electrode.
5. The touch panel according to claim 4 , wherein an electrode interval between the plurality of scanning electrodes and an electrode interval between the plurality of detecting electrodes are each at least 20 μm and no greater than 30 μm.
6. The touch panel according to claim 1 , further comprising a frequency adjustor which adjusts a frequency of the constant current source.
7. A display device with a built-in touch panel, comprising:
a display panel; and
a touch panel built into the display panel,
wherein the touch panel comprises:
a plurality of scanning electrodes formed on the display panel;
a plurality of detecting electrodes intersecting with the plurality of scanning electrodes, the plurality of detecting electrodes being formed on the display panel;
a detection signal source which sequentially connects a constant current source to each of the plurality of scanning electrodes for each one scanning period; and
a detection circuit which detects a touch position on the display panel based on a variation of a current detected at each of the plurality of detecting electrodes;
wherein, even in a case where a new current passage occurs, the constant current source operates to generate a total current amount which is constant; and
wherein the detection circuit detects a touch position by detecting the detecting electrode to which an amount of current flowing is reduced due to the new current passage.
8. The display device with a built-in touch panel according to claim 7 , wherein the plurality of scanning electrodes and the plurality of detecting electrodes are formed on different surfaces.
9. The display device with a built-in touch panel according to claim 7 ,
wherein one of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed on a surface of the display panel on a viewer side, and
wherein another of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed inside the display panel.
10. The display device with a built-in touch panel according to claim 7 ,
wherein the display panel comprises a liquid crystal display panel comprising:
a first substrate;
a second substrate; and
a liquid crystal layer sandwiched between the first substrate and the second substrate,
wherein the second substrate is arranged on a viewer side,
wherein one of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed on a surface of the second substrate on a side opposite to the liquid crystal layer, and
wherein another of the each of the plurality of scanning electrodes and the each of the plurality of detecting electrodes is formed on a surface of the first substrate on the liquid crystal layer side.
11. The display device with a built-in touch panel according to claim 7 , wherein the plurality of scanning electrodes and the plurality of detecting electrodes each comprise a stripe-type electrode.
12. The display device with a built-in touch panel according to claim 11 , wherein an electrode interval between the plurality of scanning electrodes and an electrode interval between the plurality of detecting electrodes are each at least 20 μm and no greater than 30 μm or less.
13. The display device with a built-in touch panel according to claim 7 , further comprising a frequency adjustor which adjusts a frequency of the constant current source.