Touch detecting circuit and semiconductor integrated circuit using the same
First Claim
1. A touch detecting circuit comprising:
- a charging circuit;
a detecting circuit; and
a calibration circuit,wherein the charging circuit and the detecting circuit are configured to be connected via a terminal to a sensing capacitor that is disposed on a touch panel,wherein the calibration circuit includes a calibration capacitor that is coupled to the terminal,wherein the charging circuit is configured to charge the sensing capacitor during a first period,wherein the detecting circuit is configured to discharge the sensing capacitor during a second period after the first period,wherein the calibration capacitor is configured to be charged by a first portion of electric charge that is discharged from the sensing capacitor during a third period included in the second period,wherein a second portion of the electric charge that is discharged from the sensing capacitor is discharged via a current source, during a fourth period included in the second period, andwherein a remaining portion of the electric charge discharged from the sensing capacitor is input to the detecting circuit during the second period.
5 Assignments
0 Petitions
Accused Products
Abstract
A touch detecting circuit includes a discharging circuit, a detecting circuit, and a calibration circuit that is configured with a calibration capacitor connected to a terminal and a current source which is connected to the terminal and can be controlled so as to be on and off, that can be connected via the terminal to a sensing capacitor which is disposed on a touch panel, is provided. In the beginning, the sensing capacitor is charged to a predetermined voltage by the charging circuit, thereafter, in a process of discharging, a portion of charge amount that is discharged is used to charge the calibration capacitor, and another portion is discharged via the current source, and the rest is input to the detecting circuit. The detecting circuit measures the charge amount that is input.
-
Citations
20 Claims
-
1. A touch detecting circuit comprising:
-
a charging circuit; a detecting circuit; and a calibration circuit, wherein the charging circuit and the detecting circuit are configured to be connected via a terminal to a sensing capacitor that is disposed on a touch panel, wherein the calibration circuit includes a calibration capacitor that is coupled to the terminal, wherein the charging circuit is configured to charge the sensing capacitor during a first period, wherein the detecting circuit is configured to discharge the sensing capacitor during a second period after the first period, wherein the calibration capacitor is configured to be charged by a first portion of electric charge that is discharged from the sensing capacitor during a third period included in the second period, wherein a second portion of the electric charge that is discharged from the sensing capacitor is discharged via a current source, during a fourth period included in the second period, and wherein a remaining portion of the electric charge discharged from the sensing capacitor is input to the detecting circuit during the second period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A touch detecting circuit comprising:
-
a discharging circuit, a detecting circuit, and a calibration circuit that includes a calibration capacitor that is connected to a terminal and that is configured to be coupled via the terminal to a sensing capacitor which is disposed on a touch panel, wherein the discharging circuit is configured to discharge the sensing capacitor during a first period, wherein the detecting circuit is configured to charge the sensing capacitor during a second period after the first period, wherein the calibration capacitor is configured to be discharged by a first portion of electric charge that is charged to the sensing capacitor during a third period included in the second period, wherein a second portion of the electric charge that is charged to the sensing capacitor is supplied from a current source during a fourth period included in the second period, and wherein a remainder of the electric charge charged to the sensing capacitor during the second period is input to the detecting circuit as a negative charge amount. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A semiconductor integrated circuit comprising:
-
a single semiconductor substrate on which a charging circuit, a detecting circuit, and a calibration circuit are disposed, wherein the charging circuit and the detecting circuit are configured to be connected via a terminal to a sensing capacitor that is disposed on a touch panel, wherein the calibration circuit includes a calibration capacitor that is coupled to the terminal, wherein the charging circuit is configured to charge the sensing capacitor during a first period, wherein the detecting circuit is configured to discharge the sensing capacitor during a second period after the first period, wherein the calibration capacitor is configured to be charged by a first portion of electric charge that is discharged from the sensing capacitor, during a third period included in the second period, wherein a second portion of the electric charge that is discharged from the sensing capacitor is discharged via a current source, during a fourth period included in the second period, and wherein a remaining portion of the electric charge discharged from the sensing capacitor is input to the detecting circuit, during the second period. - View Dependent Claims (20)
-
Specification