Reducing visual artifacts and reducing power consumption in electrowetting displays

Patent metadata

Field	Value
Publication number	US-9659534-B2
Application number	US-201414583994-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Dec 29, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

Subject matter disclosed herein relates to addressing schemes that reduce visual artifacts and power consumption in electrowetting display devices. The electrowetting display comprises a first substrate and a second substrate opposite to the first substrate, wherein a plurality of pixel regions are defined between the first substrate and the second substrate. The electrowetting display further comprises a first fluid within the pixel regions and a second fluid on the first fluid, wherein the second fluid is immiscible with the first fluid. The electrowetting display also comprises a timing controller that includes a memory. The timing controller is configured to drive the plurality of pixel regions with one or more addressing schemes that control rates of driving the plurality of pixel regions.

First claim

What is claimed is:

1. An electrowetting display comprising:
a first support plate and a second support plate opposite to the first support plate;
a plurality of pixel walls that intersect to separate a plurality of pixel regions, wherein the plurality of pixel regions is arranged in a grid of rows and columns, wherein an individual one of the pixel regions comprises:
a hydrophobic surface on the first support plate;
an oil on the hydrophobic surface between the first support plate and the second support plate;
a fluid that includes an electrolyte, wherein the fluid is disposed on the electrowetting oil; and
a pixel electrode, wherein when a voltage is applied to the pixel region via the pixel electrode in conjunction with a common electrode, a portion of the oil is displaced by the fluid on the hydrophobic surface;
a row driver to provide signals to rows of pixel regions and a column driver to provide signals to columns of pixel regions;
a timing controller, wherein the timing controller is configured to control the row driver and the column driver to drive pixel regions; and
a memory within the timing controller to store image data from a host system,
wherein the timing controller is configured to control, based upon the image data stored in the frame memory, the row driver and the column driver to drive the plurality of pixel regions, and
wherein the timing controller is further configured to drive the plurality of pixel regions using an addressing scheme

that reduces a rate of driving the plurality of pixel regions by omitting images within the image data from the host system.

2. The electrowetting display of claim 1 , further comprising:
a still image detector within the timing controller to detect whether new incoming image data from the image source is identical or substantially identical to previous image data received from an image source of the host system,
wherein when image data received from the image source is identical or substantially identical to previous image data received from the image source, the timing controller informs the image source to enter a sleep mode, and wherein the timing controller refreshes pixel regions using the image data stored in the memory.

3. The electrowetting display of claim 1 , wherein the individual one of the pixel regions comprises a capacitor, and wherein the timing controller controls luminance of the electrowetting display by recharging each pixel region capacitor to an original data value immediately after a reset of the pixel regions, wherein a reset sets the capacitor of the pixel region value to zero.

4. The electrowetting display of claim 1 , wherein the timing controller is further configured to pseudo-randomly address individual rows of pixel regions to drive pixel regions to brightness levels having a random distribution along columns of the pixel regions.

5. An electronic device comprising an electro wetting display, the electrowetting display comprising:
a first support plate and a second support plate opposite to the first support plate, wherein a plurality of pixel regions are defined between the first support plate and the second support plate;
a first fluid within the pixel regions;
a second fluid on the first fluid, wherein the second fluid is substantially immiscible with the first fluid; and
a timing controller that includes a memory, wherein the memory stores image data received from an image source;
wherein the timing controller drives the plurality of pixel regions, based at least in part upon image data stored within the memory, with an scheme that reduces a rate of driving the plurality of pixel regions by omitting images within the image data from the image source.

6. The electronic device of claim 5 , wherein the memory comprises a codec configured to compress the image data received from the image source.

7. The electronic device of claim 5 , wherein the timing controller is configured to interlace addressing of source image sequences with repeat sequences or refresh sequences.

8. The electronic device of claim 5 , wherein the electrowetting display further comprises a still image detector within the timing controller,
wherein when image data received from the image source is identical or substantially identical to previous image data received from the image source, the timing controller informs the image source to enter a sleep mode, and wherein the timing controller refreshes pixel regions using the image data stored in the memory.

9. The electronic device of claim 5 , wherein the timing controller is further configured to pseudo-randomly address individual rows of pixel regions to drive pixel regions to have brightness levels in a random distribution along columns of the pixel regions.

10. A method of driving an electrowetting display comprising a plurality of pixel regions arranged in a grid of columns and rows, the method comprising:
receiving image data from an image source at a first addressing rate;
detecting that the image data corresponds to image data for a still image or image data for a moving image;
resetting rows of pixel regions with a reset pulse that sets a capacitor of a pixel region value to zero;
after resetting the rows of pixel regions, addressing rows of pixel regions with the image data at a second addressing rate; and
reducing the second addressing rate by omitting frames of image data within the image data from the image source.

11. The method of claim 10 , wherein the second addressing rate is controlled independently of the first addressing rate.

12. The method of claim 10 , further comprising storing the image data within memory of a timing controller.

13. The method of claim 12 , further comprising compressing the image data stored within the memory.

14. The method of claim 10 , further comprising progressively addressing rows of pixel regions after a reset pulse.

15. The method of claim 10 , further comprising pseudo-randomly addressing rows of pixel regions after a reset pulse.

16. The method of claim 10 , further comprising alternating reset pulses with recharging of rows of pixel regions.

17. The method of claim 10 , further comprising controlling luminance of the electrowetting display by recharging a capacitor of a pixel region after resetting the capacitor of the pixel region.

18. The method of claim 10 , further comprising detecting if the image data corresponds to image data for a still image.

Assignees

• Amazon Tech Inc

Inventors

• De Greef Petrus Maria

Classifications

• G09G2300/08

  Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements · CPC title

• G09G2360/18

  Use of a frame buffer in a display terminal, inclusive of the display panel · CPC title

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• G09G2330/022

  in absence of operation, e.g. no data being entered during a predetermined time · CPC title

• G09G2320/103

  Detection of image changes, e.g. determination of an index representative of the image change · CPC title