Control circuit of mutual capacitance type electrostatic capacitive sensor and electronic device using the same
First Claim
1. A control circuit of an electrostatic capacitive sensor including a plurality of transmitter electrodes disposed in parallel in a first direction and a plurality of receiver electrodes disposed in parallel in a second direction, and spaced apart from the plurality of transmitter electrodes by specific intervals, the control circuit comprising:
- a transmitter circuit configured to apply a periodical transmission signal to each of the plurality of transmitter electrodes;
a receiver circuit configured to generate, based on a reception signal generated in each of the plurality of receiver electrodes in response to the transmission signal, a detection signal indicating a change in electrostatic capacitance formed at each of intersections of the plurality of transmitter electrodes and the plurality of receiver electrodes; and
a controller configured to control an operation mode of the transmitter circuit,wherein the transmitter circuit is configured to switch between a first mode, where the transmission signal is sequentially applied to the plurality of transmitter electrodes, and a second mode, where the plurality of transmitter electrodes are grouped and the same transmission signal is applied to a plurality of transmitter electrodes belonging to the same group, andwherein the controller switches between a first condition, where the transmitter circuit is fixedly set to the first mode in which one frame is scanned at a first predetermined time interval, and a second condition, where the transmitter circuit is set to alternate between the first mode and the second mode in which one frame is scanned at a second predetermined time interval, and a first repetition period in the first condition is shorter than a second repetition period in the second condition.
1 Assignment
0 Petitions
Accused Products
Abstract
An electrostatic capacitive sensor includes a plurality of transmitter electrodes, a plurality of receiver electrodes, and a control circuit. Further, the control circuit includes: a transmitter circuit configured to apply a periodical transmission signal to each of the plurality of transmitter electrodes; and a receiver circuit configured to generate, based on a reception signal generated in each of the plurality of receiver electrodes in response to the transmission signal, a detection signal indicating a change in electrostatic capacitance formed at each of intersections of the plurality of transmitter electrodes and the plurality of receiver electrodes, wherein the transmitter circuit is configured to switch between a first mode where the transmission signal is sequentially applied to the plurality of transmitter electrodes and a second mode where the plurality of transmitter electrodes are grouped and the same transmission signal is applied to a plurality of transmitter electrodes belonging to the same group.
15 Citations
10 Claims
-
1. A control circuit of an electrostatic capacitive sensor including a plurality of transmitter electrodes disposed in parallel in a first direction and a plurality of receiver electrodes disposed in parallel in a second direction, and spaced apart from the plurality of transmitter electrodes by specific intervals, the control circuit comprising:
-
a transmitter circuit configured to apply a periodical transmission signal to each of the plurality of transmitter electrodes; a receiver circuit configured to generate, based on a reception signal generated in each of the plurality of receiver electrodes in response to the transmission signal, a detection signal indicating a change in electrostatic capacitance formed at each of intersections of the plurality of transmitter electrodes and the plurality of receiver electrodes; and a controller configured to control an operation mode of the transmitter circuit, wherein the transmitter circuit is configured to switch between a first mode, where the transmission signal is sequentially applied to the plurality of transmitter electrodes, and a second mode, where the plurality of transmitter electrodes are grouped and the same transmission signal is applied to a plurality of transmitter electrodes belonging to the same group, and wherein the controller switches between a first condition, where the transmitter circuit is fixedly set to the first mode in which one frame is scanned at a first predetermined time interval, and a second condition, where the transmitter circuit is set to alternate between the first mode and the second mode in which one frame is scanned at a second predetermined time interval, and a first repetition period in the first condition is shorter than a second repetition period in the second condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification