Touch screen device with normal and sleep modes and method for driving the same

• US 9,696,883 B2
• Filed: 05/22/2015
• Issued: 07/04/2017
• Est. Priority Date: 12/26/2014
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Oh, Jun Seok, Lee, Sun Young, Song, Shi Cheol
• Primary Examiner(s): Snyder, Adam J
• Application Number:
  US14/720,094
• Publication Number:
  US 20160188142A1
• Time in Patent Office: 774 Days
• Field of Search: 345174, 178 1806
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04113 Peripheral electrode pattern in resistive digitisers, i.e. electrodes at the periphery of the resistive sheet are shaped in patterns enhancing linearity of induced field
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/0484 for the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a parameter value or selecting a range
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A touch sensitive display device and a method for driving the same capable of increasing the touch recognition rate of the touch sensitive display device in the sleep mode are disclosed. The touch sensitive display device supports a normal mode and a sleep mode. The display device includes touch driving lines and a touch driver to supply one or more touch driving signals to the touch driving lines. The touch driver supplies the one or more touch driving signals at a first frequency during the normal mode of the touch sensitive display device, supplies the one or more touch driving signals at a second frequency during a first portion of the sleep mode of the touch sensitive display device, and supplies the one or more touch driving signals at a third frequency during a second portion of the sleep mode of the touch sensitive display device.

Claims

1. A method of operation in a touch sensitive display device supporting a normal mode and a sleep mode, the touch sensitive display device comprising data lines coupled to pixels of the touch sensitive display device, the method comprising:

supplying one or more touch driving signals to touch driving lines at a first frequency during the normal mode of the touch sensitive display device, the data lines of the touch sensitive display device supplied with data voltages during the normal mode;

supplying the one or more touch driving signals to the touch driving lines at a second frequency lower than the first frequency during a first portion of the sleep mode immediately following the normal mode, the data lines of the touch sensitive display device not being supplied with data voltages during the sleep mode;

generating first raw touch data based on the one or more touch driving signals supplied at the second frequency during the first portion of the sleep mode;

sensing touch by comparing the first raw touch data to a first reference;

responsive to expiration of a predetermined number of frame periods in the first portion of the sleep mode without the first touch data indicating a touch, supplying the one or more touch driving signals to the touch driving lines at a third frequency lower than the second frequency during a second portion of the sleep mode;

generating second raw touch data based on the one or more touch driving signals supplied at the third frequency during the second portion of the sleep mode; and

sensing touch by comparing the second raw touch data to a second reference different than the first reference.

2. The method of claim 1, wherein the second reference is lower than the first reference.

3. The method of claim 1, further comprising:

waking the touch sensitive display device to return to the normal mode responsive to the first raw touch data exceeding the first reference during the first portion of the sleep mode.

4. The method of claim 3 further comprising:

responsive to the second raw touch data exceeding the second reference, again supplying the one or more touch driving signals to the touch driving lines at the second frequency during a third portion of the sleep mode.

5. The method of claim 4, further comprising:

responsive to third raw touch data sensed during the third portion of the sleep mode exceeding the first reference, waking the touch sensitive display device to return to the normal mode.

6. A touch sensitive display device supporting a normal mode and a sleep mode, comprising:

pixels and data lines coupled to the pixels;

touch driving lines;

a touch driver to supply one or more touch driving signals to the touch driving lines, the touch driver to;

supply the one or more touch driving signals at a first frequency during the normal mode of the touch sensitive display device, the data lines supplied with data voltages during the normal mode;

supply the one or more touch driving signals at a second frequency lower than the first frequency during a first portion of the sleep mode immediately following the normal mode, the data lines of the touch sensitive display device not being supplied with data voltages during the sleep mode,

generate first raw touch data based on the one or more touch driving signals supplied at the second frequency during the first portion of the sleep mode;

sense touch by comparing the first raw touch data to a first reference;

responsive to expiration of a predetermined number of frame periods in the first portion of the sleep mode without the first touch data indicating a touch, supply the one or more touch driving signals to the touch driving lines at a third frequency lower than the second frequency during a second portion of the sleep mode;

generate second raw touch data based on the one or more touch driving signals supplied at the third frequency during the second portion of the sleep mode; and

sense touch by comparing the second raw touch data to a second reference different than the first reference.

7. The touch sensitive display device of claim 6, wherein the second reference is lower than the first reference.

8. The touch sensitive display device of claim 6,

wherein the touch controller wakes the touch sensitive display device to return to the normal mode responsive to the first raw touch data sensed during the first portion of the sleep mode exceeding the first reference.

9. The touch sensitive display device of claim 8, wherein the touch driver again supplies the touch driving signals to the touch lines at the second frequency during a third portion of the sleep mode responsive to the second raw touch data exceeding the second reference.

10. The touch sensitive display device of claim 9, wherein the touch controller wakes the touch sensitive display device to return to the normal mode responsive to third raw touch data sensed during the third portion of the sleep mode exceeding the first reference.

11. A driver circuit to drive touch driving lines of a display device that supports a normal mode and a sleep mode, the touch sensitive display device comprising data lines coupled to pixels of the touch sensitive display device, the driver circuit comprising:

first circuitry to supply one or more touch driving signals to the touch driving lines, the first circuitry to;

supply the one or more touch driving signals at a first frequency during the normal mode of the touch sensitive display device, the data lines of the touch sensitive display device supplied with data voltages during the normal mode;

supply the one or more touch driving signals at a second frequency lower than the first frequency during a first portion of the sleep mode immediately following the normal mode, the data lines of the touch sensitive display device not being supplied with data voltages during the sleep mode, touch being sensed;

generate first raw touch data based on the one or more touch driving signals supplied at the second frequency during the first portion of the sleep mode;

sense touch by comparing the first raw touch data to a first reference;

responsive to expiration of a predetermined number of frame periods in the first portion of the sleep mode without the first touch data indicating a touch, supply the one or more touch driving signals to the touch driving lines at a third frequency lower than the second frequency during a second portion of the sleep mode; and

generate second raw touch data based on the one or more touch driving signals supplied at the third frequency during the second portion of the sleep mode; and

sense touch by comparing the second raw touch data to a second reference different than the first reference.

12. The driver circuit of claim 11 wherein the second circuitry wakes the touch sensitive display device to return to the normal mode responsive to the first touch data sensed during the first portion of the sleep mode exceeding the first reference.

13. The driver circuit of claim 12, wherein the first circuitry again supplies the touch driving signals to the touch lines at the second frequency during a third portion of the sleep mode responsive to the second raw touch data exceeding the second reference.

14. The driver circuit of claim 13, wherein the second circuitry wakes the touch sensitive display device to return to the normal mode responsive to third raw touch data sensed during the third portion of the sleep mode exceeding the first reference.