Touch screen driving device including multiplexer with cross-coupled switches

• US 9,405,416 B2
• Filed: 09/24/2014
• Issued: 08/02/2016
• Est. Priority Date: 09/25/2013
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kang, Hyeongwon
• Primary Examiner(s): BLANCHA, JONATHAN M
• Application Number:
  US14/495,163
• Publication Number:
  US 20150084923A1
• Time in Patent Office: 678 Days
• Field of Search: 345/174
• US Class Current: 1/1
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch screen driving device includes a touch screen including Tx channels, Rx channels, and sensor nodes formed at crossings of the Tx channels and the Rx channels, a Tx driving circuit supplying a Tx driving pulse to the Tx channels, sensing units sampling voltages of the sensor nodes supplied through the Rx channels, a multiplexer (mux) array including mux switches, each of which is cross-coupled with output terminals of the sensing units adjacent to each mux switch, an analog-to-digital converter converting an analog sampling signal received from the mux array into digital data, an average unit which averages the digital data and removes noise included in the digital data, and a touch controller which analyzes the digital data, in which the noise is removed, using a touch recognition algorithm and outputs touch data including coordinate information of a touch position.

Claims

1. A touch screen driving device, comprising:

a touch screen including Tx channels, Rx channels crossing the Tx channels, and sensor nodes at crossings of the Tx channels and the Rx channels;

a Tx driving circuit to supply a Tx driving pulse to the Tx channels;

a plurality of sensing units to sample voltages of the sensor nodes supplied through the Rx channels in response to an Rx sampling clock;

a multiplexer (mux) array including a plurality of mux switches with one of the plurality of mux switches corresponding to one each of the plurality sensing units, respectively, each of which is simultaneously cross-coupled with output terminals of the sensing units adjacent to each mux switch, wherein each mux switch outputs data for the corresponding sensing unit and an adjacent sensing unit;

an analog-to-digital converter to convert an analog sampling signal sequentially received from the mux array into digital data;

an average unit to average the digital data received from the analog-to-digital converter and remove noise included in the digital data; and

a touch controller to analyze the digital data, in which the noise is removed, using a previously determined touch recognition algorithm and output touch data including coordinate information of a touch position.

2. The touch screen driving device of claim 1, further comprising an integrator to integrate and accumulate the digital data, in which the noise is removed, and supply the accumulated digital data to the touch controller.

3. The touch screen driving device of claim 1, wherein a kth mux switch among the plurality of mux switches is simultaneously connected to an output terminal of a kth sensing unit, an output terminal of a (k−

1)th sensing unit, and an output terminal of a (k+1)th sensing unit, where k is a positive integer,

wherein the kth mux switch outputs an output signal including a kth analog sampling signal received from the kth sensing unit, a (k−

1)th analog sampling signal received from the (k−

1)th sensing unit, and a (k+1)th analog sampling signal received from the (k+1)th sensing unit.

4. The touch screen driving device of claim 1, wherein the average unit sequentially latches the digital data received from the analog-to-digital converter and then averages the latched digital data.