Flexible printed circuit for connecting touch screen and liquid crystal display device using the same

• US 9,426,882 B2
• Filed: 03/15/2013
• Issued: 08/23/2016
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kwon, Sujin, Kim, SungChul
• Primary Examiner(s): Nguyen, Chanh
• Assistant Examiner(s): Shen, Yuzhen
• Application Number:
  US13/839,540
• Publication Number:
  US 20130241873A1
• Time in Patent Office: 1,257 Days
• Field of Search: 345/173
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means
• 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
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes

Abstract

Discussed is a Flexible Printed Circuit (FPC). The FPC includes a plurality of touch lines respectively connected to a plurality of touch electrode lines, a first film adhered to the touch lines, a second film overlapping the first film at an upper end surface of the first film and covering the touch lines, and a feedback compensation signal electrode adhered to a lower end surface of the first film, and receiving a feedback compensation signal for removing noise.

Claims

1. A Flexible Printed Circuit (FPC) for connecting a touch screen, comprising:

a plurality of touch lines respectively connected to a plurality of touch electrode lines;

a first film adhered to the touch lines;

a second film overlapping the first film at an upper end surface of the first film and covering the touch lines; and

a feedback compensation signal electrode adhered to a lower end surface of the first film, and receiving a feedback compensation signal for removing noise,

wherein the feedback compensation signal electrode is provided as a plurality of lines disposed under and respectively corresponding to the touch lines in a one-to-one manner, and

wherein the feedback compensation signal electrode receives the feedback compensation signal that inverts a feedback common voltage from a display panel.

2. The FPC of claim 1, wherein,

a plurality of touch line pads respectively connected to a plurality of touch line pins of a touch board connector are disposed at respective distal ends of the touch lines, and

a feedback compensation signal electrode pad connected to a feedback compensation signal electrode pin of the touch board connector is disposed at a distal end of the feedback compensation signal electrode.

3. The FPC of claim 2, wherein,

the touch lines are respectively connected to a plurality of driving electrode lines receiving a noise driving signal having noise among the touch electrode lines, and

the touch line pads are respectively connected to a plurality of touch line pins connected to a touch driver of a touch IC among a plurality of pins arranged in the touch board connector.

4. The FPC of claim 2, wherein,

the touch lines are respectively connected to a plurality of receiving electrode lines receiving a noise sensing signal having noise among the touch electrode lines, and

the touch line pads are respectively connected to a plurality of touch line pins connected to a touch sensing unit of a touch IC among a plurality of pins arranged in the touch board connector.

5. A Liquid Crystal Display (LCD) device, comprising:

a panel, a plurality of data lines and a plurality of gate line being arranged in the panel;

a touch screen comprising a plurality of touch electrodes for sensing a touch;

a plurality of touch electrode lines respectively connected to the touch electrodes;

a touch IC determining whether the touch electrodes are touched using a sensing signal generated by a driving signal applied to the touch electrodes;

a touch board connector mounted on the touch board with the touch IC mounted thereon, and connected to the touch IC;

a Flexible Printed Circuit (FPC) connecting the touch electrode lines to the touch board connector;

a common voltage generator supplying a common voltage to a plurality of common electrodes disposed in the panel; and

a compensation signal generator inverting a noise signal fed back from a feedback common voltage from the panel to generate a feedback compensation signal, and transferring the feedback compensation signal to the touch board connector,

wherein a feedback compensation signal electrode receiving the feedback compensation signal through the touch board connector and a plurality of touch lines respectively connected to the plurality of the touch electrode lines are disposed in the FPC,

the touch lines are adhered to an upper end surface of a first film and the feedback compensation signal electrode is adhered to a lower end surface of the first film, and

the feedback compensation signal electrode is provided as a plurality of lines disposed under and respectively corresponding to the touch lines in a one-to-one manner, and

wherein the feedback compensation signal electrode receives the inverted noise signal fed back from the panel.

6. The LCD device of claim 5, wherein,

the noise signal is a feedback common voltage which is applied from the common voltage generator to the panel and fed back from the panel with noise being added into the feedback common voltage, and

the feedback compensation signal is generated by inverting the feedback common voltage.

7. The LCD device of claim 5, wherein,

the FPC is a driver FPC that transfers a driving signal applied to the touch screen, or

the FPC is a sensor FPC that applies a sensing signal, applied from the touch screen, to the touch IC.

8. The LCD device of claim 5, wherein,

the touch screen is a capacitive touch screen using a mutual type, or

the touch screen is a capacitive touch screen using a self-cap type.

9. The LCD device of claim 5, wherein,

the touch screen and the panel are provided as one body, or

the touch screen is adhered to an upper glass substrate configuring the panel.