Display device, method for driving display device, and electronic equipment

• US 8,872,783 B2
• Filed: 04/06/2012
• Issued: 10/28/2014
• 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
• Primary Examiner(s): PATEL, PREMAL R
• Application Number:
  US13/984,338
• Publication Number:
  US 20130314360A1
• Time in Patent Office: 935 Days
• Field of Search: 345173-179, 178 1801- 1809
• 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

A display device; a method for driving the display device; and electronic equipment, each enabling a detection device to perform detection with a frequency higher than a refresh frequency of the display device and with improved accuracy are provided. The display device 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 a detection instructing circuit configured to output detection operation control signals corresponding to touch panel detection periods to the detection device in at least one pause frame. The detection instruction signal instructs the detection device to detect at least one of detection targets which are input by touching or approaching the screen and a radio wave coming from outside the display device.

Claims

1. A display device comprising:

a screen including a plurality of pixels,

a detection device configured to perform a detection operation for the screen, the detection operation includes detecting a position of an input made by an object touching or approaching the screen; and

a detection instructing circuit configured to output a detection operation control signal to the detection device;

wherein

the screen repeatedly alternates 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 detection operation control signal includes a plurality of pulses which occur during at least one of the non-scanning periods, each of the plurality of pulses correspond to the detection operation, the detection operation control signal is a signal which instructs the detection device to perform the detection operation on detection targets which are the input made by the object touching or approaching the screen; and

the detection device determines a timing for each of the detections 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 a corresponding one of the scanning periods.

2. The display device as set forth in claim 1, wherein the non-scanning periods are longer than the scanning periods.

3. The display device as set forth in claim 2, wherein

the display device holds:

Ts≧

Ttp×

2+Tint

wherein Ts represents the at least one of the non-scanning periods, 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.

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

the non-scanning periods are equivalent to an integer multiple of the scanning periods,

the non-scanning periods are equivalent to twice the scanning-periods, 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.

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

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

in the non-scanning periods, 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.

6. A display device, comprising:

a screen including a plurality of pixels,

a detection device configured to perform a detection operation for the screen, the detection operation includes detecting a position of an input made by an object touching or approaching the screen; and

a detection instructing circuit configured to output a detection operation control signal to the detection device;

wherein

the screen repeatedly alternates 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 detection operation control signal includes a plurality of pulses which occur during at least one of the non-scanning periods, each of the plurality of pulses correspond to the detection operation, the detection operation control signal is a signal which instructs the detection device to perform the detection operation on detection targets which are the input made by the object touching or approaching the screen,

the detection device is a touch panel provided on the screen of the display device,

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 operation control signal at a number of times which number is determined in accordance with the velocity information.

7. A method for driving a display device including:

a screen with a plurality of pixels;

a detection device configured to perform a detection operation for the screen, the detection operation includes detecting a position of an input made by an object touching or approaching the screen; and

a detection instructing circuit configured to output a detection operation control signal to the detection device;

wherein

the screen repeatedly alternates 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, and

the detection device determines a timing for each of the detections 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 a corresponding one of the scanning periods,

the method comprising the step of;

outputting the detection operation control signal which includes a plurality of pulses which occur during at least one of the non-scanning periods, each of the plurality of pulses correspond to the detection operation, the detection operation control signal is a signal which instructs the detection device to perform the detection operation on detection targets which are the input made by the object touching or approaching the screen.