DISPLAY DEVICE, METHOD FOR DRIVING DISPLAY DEVICE, AND ELECTRONIC EQUIPMENT

• US 20130314360A1
• Filed: 04/06/2012
• Published: 11/28/2013
• Est. Priority Date: 04/15/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Saitoh, Kohji, Fujioka, Akizumi, Ozaki, Masami, Yanagi, Toshihiro
• Granted Patent: US 8,872,783 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general

Abstract

Provided are a display device (2); a method for driving it; and electronic equipment (1), each enabling a detection device (3) to make detection with a frequency higher than a refresh frequency of the display device (2) and with improved accuracy. The display device (2) has a screen including pixels and repeatedly alternates between a scanning frame during which the pixels are scanned to be sequentially brought into a selected state and a pause frame during which the pixels are not scanned, and includes detection instructing means for outputting detection instruction signals corresponding to touch panel detection periods Ttp to the detection device (3) in at least one pause frame. The detection instruction signal instructs the detection device (3) to make detections of at least one of detection targets which are input made by touching or approaching the screen and a radio wave coming from outside the display device (2).

Claims

1. A display device having a screen including a plurality of pixels, the display device repeatedly alternating between (a) each of scanning periods during which the plurality of pixels are scanned in such a manner that the plurality of pixels are sequentially brought into a selected state and (b) each of non-scanning periods during which the plurality of pixels are not scanned at all,

the display device comprising:

detection instructing means for outputting a detection instruction signal to a detection device plural times in at least one of the non-scanning periods, the detection instruction signal being a signal for instructing the detection device to make detections of at least one of detection targets which are (i) an input made by a touch of the screen or an approach to the screen and (ii) a radio wave coming from outside the display device.

2. The display device as set forth in claim 1, wherein the detection device determines a timing for each of the detection in such a manner as to minimize a difference between (i) an interval between two consecutive detections, of the detections, made in a corresponding one of the non-scanning periods and (ii) an interval between two consecutive detections, of the detections, made in a period including corresponding one of the scanning periods.

3. The display device as set forth in claim 2, wherein the non-scanning period is longer than the scanning period.

4. The display device as set forth in claim 3, wherein

the display device holds:

Ts≧

Ttp×

2+Tint

wherein Ts represents the non-scanning period, Ttp represents a period required for the detection, and Tint represents the interval between the two consecutive detections in the corresponding one of the non-scanning periods.

5. The display device as set forth in claim 1, wherein

the plurality of pixels are provided in such a manner as to respectively correspond to intersections between a plurality of scanning signal lines extending in one direction and a plurality of data signal lines extending in other direction,

the display device further comprises:

a scanning line driving circuit that sequentially applies, on the plurality of scanning signal lines, a selection signal which is a signal for switching the scanning signal line to a selected state;

a signal line driving circuit that supplies an image data signal to each of the data signal lines; and

a control circuit that outputs the selection signal to the scanning line driving circuit in accordance with a vertical sync signal supplied from outside and outputs, to the signal line driving circuit, a supply instruction signal for instructing

the signal line driving circuit to supply the image data signal, in accordance with a horizontal sync signal supplied from outside,

the signal line driving circuit includes signal line driving sections, the number of which is set according to the number of the data signal lines, and

one of the signal line driving sections includes the detection instructing means.

6. The display device as set forth in claim 1, wherein the non-scanning period is equivalent to an integer multiple of the scanning period.

7. The display device as set forth in claim 6, wherein

the non-scanning period is equivalent to a double of the scanning-period, and

each of the detections which is made in a former half of a corresponding one of the non-scanning periods is started earlier than each of the detections which is made in a latter half of the corresponding one of the non-scanning periods.

8. The display device as set forth in claim 1, wherein

the non-scanning period is a period equivalent to an odd multiple of the scanning period, and

in the non-scanning period, each of the detections is started at a same time in each of odd-numbered periods which are each equivalent in length to the scanning period, and each of the detections is ended at a same time in each of the odd-numbered periods.

9. The display device as set forth in claim 1, wherein

the plurality of pixels are provided in such a manner as to respectively correspond to intersections between a plurality of scanning signal lines extending in one direction and a plurality of data signal lines extending in other direction,

the display device further comprises:

a scanning line driving circuit that sequentially applies, on the plurality of scanning signal lines, a selection signal which is a signal for switching the scanning signal line to a selected state;

a signal line driving circuit that supplies an image data signal to each of the data signal lines; and

a control circuit that outputs the selection signal to the scanning line driving circuit in accordance with a vertical sync signal supplied from outside and outputs, to the signal line driving circuit, a supply instruction signal for instructing the signal line driving circuit to supply the image data signal, in accordance with a horizontal sync signal supplied from outside, and

the control circuit includes the detection instructing means.

10. The display device as set forth in claim 1, wherein

the plurality of pixels are provided in such a manner as to respectively correspond to intersections between a plurality of scanning signal lines extending in one direction and a plurality of data signal lines extending in other direction,

the display device further comprises:

a scanning line driving circuit that sequentially applies, on the plurality of scanning signal lines, a selection signal which is a signal for switching the scanning signal line in a selected state;

a signal line driving circuit that supplies an image data signal to each of the data signal lines;

a control circuit that outputs the selection signal to the scanning line driving circuit in accordance with a vertical sync signal supplied from outside and outputs, to the signal line driving circuit, a supply instruction signal for instructing the signal line driving circuit to supply the image data signal, in accordance with a horizontal sync signal supplied from outside; and

a centralized control section that supplies the vertical sync signal and the horizontal sync signal, and

the control circuit outputs the detection instruction signal to the detection device via the centralized control section.

11. The display device as set forth in claim 5, wherein

the scanning line driving circuit, the signal line driving circuit, and the control circuit invert a polarity of a voltage to be applied to each of the pixels during the scanning period.

12. The display device as set forth in claim 1, wherein the display device is a liquid crystal display device.

13. The display device as set forth in claim 1, wherein the display device is an organic electroluminescence display device.

14. The display device as set forth in claim 1, wherein the detection device is a touch panel provided on the screen of the display device.

15. The display device as set forth in claim 14, wherein

the detection device generates velocity information on a velocity of movement of the detection target on the screen, and

in at least one of the non-scanning periods, the display device outputs the detection instruction signal at a number of times which number is determined in accordance with the velocity information.

16. The display device as set forth in claim 1, wherein the detection device is an RF reception device for (i) detecting a radio wave coming from outside and (ii) receiving a signal included in the radio wave.

17. The display device as set forth in claim 1, wherein

the pixels of the display device each include a TFT, and

the TFT includes a semiconductor layer made of an oxide semiconductor.

18. The display device as set forth in claim 17, wherein the oxide semiconductor is In—

Ga—

Zn—

O.

19. Electronic equipment, comprising:

a display device as set forth in claim 1; and

the detection device.

20. A method for driving a display device having a screen including a plurality of pixels, the display device repeatedly alternating between (a) each of scanning periods during which the plurality of pixels are scanned in such a manner that the plurality of pixels are sequentially brought into a selected state and (b) each of non-scanning periods during which the plurality of pixels are not scanned at all,

the method comprising the step of:

outputting a detection instruction signal to a detection device plural times in at least one of the non-scanning periods, the detection instruction signal being a signal for instructing the detection device to make detections of at least one of detection targets which are (i) an input made by a touch of the screen or an approach to the screen and (ii) a radio wave coming from outside the display device.