MID-FRAME BLANKING

• US 20150355762A1
• Filed: 06/04/2014
• Published: 12/10/2015
• Est. Priority Date: 06/04/2014
• Status: Abandoned Application

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tripathi, Brijesh, Agarwal, Manu, Holland, Peter F.
• Application Number:
  US14/296,105
• Publication Number:
  US 20150355762A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 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 3/04166 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: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 3/24 Blanking circuits

Abstract

Systems, apparatuses, and methods for performing mid-frame blanking. A first portion of a frame is driven to a display and then a first mid-frame blanking interval is generated. Following this first mid-frame blanking interval, a second portion of the frame is driven to the display, followed by a second mid-frame blanking interval, followed by a third portion of the frame, and so on. Any number of mid-frame blanking intervals may be introduced in a given frame. During each mid-frame blanking interval, touch sensing is performed to detect touch events on the screen for in-cell touch type displays. For displays with touch sensors electrically separated from the display common voltage layer, special sense scan steps are performed during mid-frame blanking intervals. By performing touch sensing or special sense scan steps during a frame rather than only at the end of a frame, the performance of touch sensing is improved.

Claims

1. An apparatus comprising:

a touch sensitive display; and

circuitry configured to drive frames to the display;

wherein the apparatus is configured to;

drive a portion of a given frame to the display, said portion representing less than all of the given frame;

insert a first mid-frame blanking interval subsequent to driving said portion and prior to driving the entire given frame;

enable touch sensing on the display during the first mid-frame blanking interval; and

resume driving the given frame.

2. The apparatus as recited in claim 1, wherein touch sensing is disabled while driving frames to the display, and wherein the display circuitry is configured to insert a plurality of mid-frame blanking intervals for each frame of a plurality of frames driven to the display.

3. The apparatus as recited in claim 1, wherein touch scans are enabled while driving frame data to the display, and wherein a stylus scan is enabled during the first mid-frame blanking interval.

4. The apparatus as recited in claim 1, wherein the apparatus is configured to insert said mid-frame blanking interval responsive to detecting a first mode of operation.

5. The apparatus as recited in claim 4, wherein the apparatus is configured to enable touch sensing only during periods between entire frames responsive to detecting a second mode of operation.

6. The apparatus as recited in claim 5, wherein for a given frame rate the apparatus is configured to:

generate a first vertical blanking interval with a first duration while operating in the second mode; and

generate a second vertical blanking interval and one or more mid-frame blanking intervals while operating in the first mode, wherein a cumulative duration of the second vertical blanking interval and the one or more mid-frame blanking intervals is equal to the first duration.

7. The apparatus as recited in claim 1, wherein the circuitry comprises one or more pixel processing pipelines, and wherein the circuitry is configured to:

stall the one or more pixel processing pipelines during the first mid-frame blanking interval;

generate dummy pixels during the first mid-frame blanking interval; and

discard or ignore the dummy pixels prior to the dummy pixels reaching the display.

8. A device comprising:

a touch sensitive display; and

logic configured to drive frames to the display;

wherein the device is configured to;

insert a first mid-frame blanking interval in an active period for a given frame; and

perform touch sensing on the display during the first mid-frame blanking interval.

9. The device as recited in claim 8, wherein the logic is configured to:

drive a first portion of the given frame to the display prior to the first mid-frame blanking interval; and

drive a second portion of the given frame to the display after the first mid-frame blanking interval.

10. The device as recited in claim 8, wherein the logic is configured to insert a plurality of mid-frame blanking intervals in the active period for each frame of a plurality of frames driven to the display.

11. The device as recited in claim 10, wherein each mid-frame blanking interval of the plurality of mid-frame blanking intervals is defined by a location and a width, wherein the location specifies where in the given frame the mid-frame blanking interval should be inserted, wherein the width specifies a duration of the mid-frame blanking interval, and wherein the location and width of each mid-frame blanking interval are programmable.

12. The device as recited in claim 10, wherein the logic is further configured to increase a number of mid-frame blanking intervals which are inserted in the active period in response to an indication that the device is running an application which would benefit from an increase in a frequency of touch sensing.

13. The device as recited in claim 8, wherein the logic is configured to drive frames to the display at a first frequency, wherein touch sensing is performed on the display at a second frequency, and wherein the second frequency is a multiple of the first frequency.

14. The device as recited in claim 8, wherein the logic comprises one or more pixel processing pipelines, wherein the logic is configured to:

stall the one or more pixel processing pipelines during the first mid-frame blanking interval; and

generate dummy pixels during the first mid-frame blanking interval.

15. A method comprising:

driving a portion of a given frame to a display, said portion representing less than all of the given frame;

inserting a first mid-frame blanking interval subsequent to driving said portion and prior to driving the entire given frame;

enabling touch sensing on the display during the first mid-frame blanking interval; and

resuming driving the given frame.

16. The method as recited in claim 15, further comprising disabling touch sensing on the display during the active period

17. The method as recited in claim 15, further comprising inserting a plurality of mid-frame blanking intervals for each frame of a plurality of frames driven to the display.

18. The method as recited in claim 17, further comprising inserting said mid-frame blanking interval responsive to detecting a first mode of operation.

19. The method as recited in claim 18, further comprising enabling touch sensing only during periods between entire frames responsive to detecting a second mode of operation.

20. The method as recited in claim 15, further comprising:

generating a first vertical blanking interval with a first duration while operating in the second mode; and

generating a second vertical blanking interval and one or more mid-frame blanking intervals while operating in the first mode, wherein a cumulative duration of the second vertical blanking interval and the one or more mid-frame blanking intervals is equal to the first duration.