Liquid crystal display device

• US 10,437,115 B2
• Filed: 11/13/2017
• Issued: 10/08/2019
• Est. Priority Date: 05/13/2015
• Status: Active Grant

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: Kimura, Yukihiro, Fukuyoshi, Kenzo
• Primary Examiner(s): Balaoing, Ariel A
• Application Number:
  US15/810,658
• Publication Number:
  US 20180067366A1
• Time in Patent Office: 694 Days
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13712 the liquid crystal having negative dielectric anisotropy
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/122 having a particular pattern
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2202/10 semiconductor
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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

Abstract

A liquid crystal display device includes a display-device substrate having a transparent electrode; an array substrate having a pixel electrode, a source line, a gate line, and a conductive line; a liquid crystal layer sandwiched between the display-device substrate and initially aligned vertically; and a controller that drives the liquid crystal layer by supplying an image signal to the source line and applying a liquid crystal driving voltage across the transparent electrode and the pixel electrode in synchronization with the image signal, the controller applying a voltage to the conductive line after the liquid crystal driving voltage is applied to the pixel electrode and while the liquid crystal driving voltage is not applied to the pixel electrode, thereby generating an electric field oriented in a direction intersecting the source line in a plan view between the conductive lines.

Claims

1. A liquid crystal display device, comprising:

a display-device substrate including a transparent substrate, a transparent resin layer formed on the transparent substrate, and a transparent electrode formed on the transparent resin layer;

an array substrate including a source line, a gate line, a pixel electrode positioned in each of pixel openings defined by the source and gate lines, a first insulation layer formed between the source line and the pixel electrode in a cross-sectional view, and a conductive line parallel to the source line and formed on the first insulation layer in a portion where pixel electrodes are divided in a plan view;

a liquid crystal layer sandwiched between the display-device substrate and the array substrate and including liquid crystal molecules having negative dielectric anisotropy and initially aligned vertically; and

a controller configured to drive the liquid crystal layer by supplying an image signal to the source line and applying a liquid crystal driving voltage across the transparent electrode and the pixel electrode in synchronization with the image signal,

wherein the controller is configured to apply a voltage to the conductive line after the liquid crystal driving voltage is applied to the pixel electrode and while the liquid crystal driving voltage is not applied to the pixel electrode, such that an electric field oriented in a direction traversing the source line in the plan view is generated between conductive lines.

2. The liquid crystal display device according to claim 1, wherein the controller is configured such that a voltage applied to the conductive line includes a positive voltage and a negative voltage, and that the voltage is inverted to be positive or negative for each fixed period of an image display.

3. The liquid crystal display device of claim 1, further comprising:

a backlight unit formed on a rear or a side surface of the array substrate and configured such that light emission of the backlight unit is stopped during application of the voltage to the conductive line.

4. The liquid crystal display device of claim 1, wherein the transparent electrode has, in a portion where the gate line is located, a stripe pattern in which slits parallel in the plan view are formed, and the source and gate lines are orthogonal to each other in the plan view and form a matrix pattern along a side of the pixel opening.

5. The liquid crystal display device of claim 4, further comprising:

a touch sensing line formed at an interface between the transparent substrate and the transparent resin layer, at a position corresponding to a location of a slit of the transparent electrode in the plan view.

6. The liquid crystal display device of claim 5, wherein the touch sensing line comprises a black layer formed on the transparent substrate and a first metal layer formed on the black layer.

7. The liquid crystal display device of claim 5, wherein the controller includes a touch sensing function of detecting a change in electrostatic capacitance between the touch sensing line and the conductive line, and the controller is configured to apply a touch sensing driving voltage to one of the touch sensing line and the conductive line after the liquid crystal driving voltage is applied to the pixel electrode and while the liquid crystal driving voltage is not applied to the pixel electrode, such that a touch sensing signal is detected through the other of the touch sensing line and the conductive line.

8. The liquid crystal display device of claim 6, wherein the controller includes a touch sensing function of detecting a change in electrostatic capacitance between the touch sensing line and the conductive line, and the controller is configured to apply a touch sensing driving voltage to one of the touch sensing line and the conductive line after the liquid crystal driving voltage is applied to the pixel electrode and while the liquid crystal driving voltage is not applied to the pixel electrode, such that a touch sensing signal is detected through the other of the touch sensing line and the conductive line.

9. The liquid crystal display device of claim 7, wherein the controller is configured to control the touch sensing driving voltage to be applied to the conductive line, and the touch sensing line detects the touch sensing signal.

10. The liquid crystal display device of claim 1, wherein the conductive line includes a second metal layer.

11. The liquid crystal display device of claim 10, further comprising:

an active element that is a thin film transistor including a source electrode electrically connected to the source line, a gate electrode electrically connected to the gate line, and a channel layer comprising a semiconductor,

wherein the second metal layer has a portion that forms a light shielding layer covering the channel layer.

12. The liquid crystal display device of claim 11, wherein the channel layer includes an oxide semiconductor.

13. The liquid crystal display device of claim 1, wherein the array substrate includes a second insulation layer formed under the first insulation layer, and a common electrode formed between the second insulation layer and the pixel electrode, and the common electrode has a portion overlapping with the pixel electrode and a portion protruding from an end of the pixel electrode in the plan view.

14. The liquid crystal display device of claim 1, wherein the display-device substrate has at least one of a red filter, a green filter, and a blue filter formed thereon at a location corresponding to the pixel opening.

15. The liquid crystal display device of claim 5, further comprising:

a black matrix layer formed at a location from a position of the touch sensing line to a position of the transparent electrode in a thickness direction of the display-device substrate such that the black matrix layer defines the pixel opening.

16. The liquid crystal display device of claim 6, wherein the first metal layer is a copper-containing layer, and the touch sensing line has a structure in which the copper-containing layer is sandwiched between conductive metal oxide layers.

17. The liquid crystal display device of claim 10, wherein the second metal layer is a copper-containing layer, and the conductive line has a structure in which the copper-containing layer is sandwiched between conductive metal oxide layers.

18. The liquid crystal display device of claim 16, wherein the conductive metal oxide layers each comprises a composite oxide including zinc oxide, indium oxide, and tin oxide.

19. The liquid crystal display device of claim 17, wherein the conductive metal oxide layers each comprise a composite oxide including zinc oxide, indium oxide, and tin oxide.

20. The liquid crystal display device of claim 1, wherein each of pixels corresponding to the pixel opening includes a first active element and a second active element, the first active element has a source electrode electrically connected to a source line to which an image signal is supplied as a negative voltage, and the second active element has a source electrode electrically connected to a source line to which an image signal is supplied as a positive voltage.