LIQUID CRYSTAL DISPLAY DEVICE

• US 20160202820A1
• Filed: 12/29/2015
• Published: 07/14/2016
• Est. Priority Date: 01/09/2015
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: ITO, Daisuke, MIZUHASHI, Hiroshi, HAYASHI, Makoto, TERANISHI, Yasuyuki, KATSUTA, Tadayoshi
• Granted Patent: US 10,168,808 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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: G09G 3/3674 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A liquid crystal display device includes: a liquid crystal element array including liquid crystal display elements arranged in a matrix form; scan lines arranged in each row of the liquid crystal element array and configured to supply scan signals to the liquid crystal display elements arranged in a corresponding row; signal lines arranged in each column of the liquid crystal element array and configured to supply image signals to the liquid crystal display elements arranged in a corresponding column; a plurality of driving electrodes arranged in the liquid crystal element array and supplied with driving signals for detecting an external proximity object; a first voltage line of a first voltage; a second voltage line of a second voltage; and a third voltage line of a third voltage.

Claims

1. A liquid crystal display device comprising:

a liquid crystal element array including a plurality of liquid crystal display elements arranged in a matrix form;

a plurality of scan lines arranged in each row of the liquid crystal element array and configured to supply scan signals to the plurality of liquid crystal display elements arranged in a corresponding row;

a plurality of signal lines arranged in each column of the liquid crystal element array and configured to supply image signals to the plurality of liquid crystal display elements arranged in a corresponding column;

a plurality of driving electrodes arranged in the liquid crystal element array and supplied with driving signals for detecting an external proximity object;

a first voltage line configured to supply a first voltage;

a second voltage line configured to supply a second voltage different from the first voltage; and

a third voltage line being a voltage line different from the first voltage line and the second voltage line and configured to supply a third voltage,

wherein in a period of detecting the external proximity object, a selected driving electrode among the plurality of driving electrodes is alternately electrically connected to the first voltage line and the second voltage line, and the selected driving electrode is supplied with the driving signal, and

unselected driving electrodes among the plurality of driving electrodes are electrically connected to the third voltage line.

2. The liquid crystal display device according to claim 1,

wherein the second voltage and the third voltage have the same voltage value.

3. The liquid crystal display device according to claim 2,

wherein the liquid crystal display device includes a low-pass filter, and

the second voltage line, the third voltage line, and the low-pass filter are electrically connected to one another in an outside of the liquid crystal element array.

4. The liquid crystal display device according to claim 2,

wherein a line width of the third voltage line is narrower than a line width of the second voltage line.

5. The liquid crystal display device according to claim 4,

wherein the liquid crystal display device includes a first driving circuit connected to the plurality of driving electrodes, the first voltage line, the second voltage line, and third voltage line, and

the first driving circuit electrically connects unselected driving electrodes to the third voltage line in a period of detecting the external proximity object, and periodically connects a selected driving electrode to the second voltage line instead of the third voltage line.

6. The liquid crystal display device according to claim 5,

wherein the first driving circuit includes a plurality of determination circuits respectively corresponding to the plurality of driving electrodes, and

the plurality of determination circuits determine whether or not a corresponding driving electrode is a selected driving electrode, based on received selection signals in a period of detecting the external proximity object.

7. The liquid crystal display device according to claim 6,

wherein the plurality of driving electrodes are the first electrodes of the plurality of liquid crystal display elements, and

in a period of performing display corresponding to the image signals, the second voltage line and the third voltage line are electrically connected to the driving electrodes.

8. The liquid crystal display device according to claim 7,

wherein the plurality of driving electrodes are arranged in a column of the liquid crystal element array, and

the first driving circuit is arranged along one side of the liquid crystal element array along a row of the liquid crystal element array.

9. The liquid crystal display device according to claim 8,

wherein the liquid crystal display device includes a second driving circuit arranged along the other side of the liquid crystal element array along the row of the liquid crystal element array, and

the second driving circuit receives a selection signal through a predetermined signal line among the plurality of signal lines in a period of detecting the external proximity object, alternately electrically connects a driving electrode, which is determined as a driving element selected by the selection signal, to the first voltage line and the second voltage line, and connects unselected driving electrodes to the third voltage line.

10. The liquid crystal display device according to claim 7,

wherein the liquid crystal display device includes an amplification unit configured to amplify a change in voltages of the driving electrodes in a period of detecting the external proximity object.

11. A liquid crystal display device comprising:

a liquid crystal element array including a plurality of liquid crystal display elements arranged in a matrix form;

a plurality of driving electrodes arranged in the liquid crystal element array and supplied with driving signals for detecting an external proximity object;

a voltage line configured to supply a voltage in a period of detecting the external proximity object;

a driving signal forming circuit configured to form a plurality of driving signals respectively corresponding to the plurality of driving electrodes; and

a determination circuit configured to determine a selected driving electrode among the plurality of driving electrodes, based on the plurality of driving signals in a period of detecting the external proximity object, supply a driving signal formed by the driving signal forming circuit to a driving electrode determined as the selected driving electrode, and electrically connect driving electrodes, which are determined as unselected electrodes, to the voltage line.

12. The liquid crystal display device according to claim 11,

wherein the determination circuit determines a driving electrode corresponding to a driving signal, whose voltage is periodically changed, as the selected driving electrode, in a period of detecting the external proximity object, and supplies the driving signal, whose voltage is periodically changed, to the selected driving electrode.