Control device, display device and method for controlling display device

• US 8,723,858 B2
• Filed: 08/30/2011
• Issued: 05/13/2014
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yamada, Yusuke
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Ritchie, Darlene M
• Application Number:
  US13/220,784
• Publication Number:
  US 20120062547A1
• Time in Patent Office: 987 Days
• Field of Search: 345/87, 345/107, 345/94, 345/530, 345/672, 345/560, 345204-215, 345690-699, 345/100
• US Class Current: 345/214
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

A control device includes a writing device that writes an image according to image data, through a plurality of frame periods, to a plurality of pixels that compose a display section, and a refresh processing device that performs refreshing a group of pixels that is subject to refreshing among the plurality of pixels when a value concerning the number of times of image writing performed by the writing device since the last refreshing is equal to or greater than a threshold value. While the refresh processing device is performing refreshing, the writing device does not perform image writing with respect to the group of pixels that is subject to the refreshing, but performs image writing with respect to a group of pixels that is not subject to the refreshing.

Claims

1. A control device comprising:

a writing device that writes an image according to image data to a plurality of pixels that compose a display section, each of the plurality of pixels assuming one of a plurality of display states including at least a first display state and a second display state by the writing device;

a specifying device that specifies a group of pixels that is subject to refreshing among the plurality of pixels; and

a refresh processing device that performs refreshing for the group of pixels when a count of the number of times of image writing performed by the writing device with respect to the group of pixels specified by the specifying device since the last refreshing is equal to or greater than a threshold value,

wherein the threshold value is representative of a predetermined count representing the number of times that writing is performed, with respect to at least one pixel among the group of pixels specified by the specifying device, from the first display state to the second display state, and the number of times that writing is performed, with respect to at least one pixel among the group of pixels specified by the specifying device, from the second display state to the first display state,

wherein, while the refresh processing device is performing refreshing, the writing device does not perform image writing with respect to the group of pixels that is subject to the refreshing, but performs image writing with respect to a group of pixels that is not subject to the refreshing.

2. A control device according to claim 1, wherein the writing device includes:

a rewrite judging device that judges as to whether or not a new write instruction occurs with respect to one pixel of the plurality of pixels;

a write state judging device that judges, when it is judged that the new write instruction occurs, as to whether or not an image write operation is in progress with respect to the one pixel; and

a write control device that, when the write state judging device judges that a write operation is not in progress with respect to the one pixel, stores first write data indicative of the number of times of drive voltage application to change the display state of the pixel from the first display state to the second display state, or second write data indicative of the number of times of drive voltage application to change the display state of the pixel from the second display state to the first display state in a first memory region, and performs a write control of applying a drive voltage a plurality of times to the one pixel based on the first write data or the second write data stored in the first memory region, and, when the write state judging device judges that a write operation is in progress with respect to the one pixel, continues the write operation in progress, and performs the write control upon completion of the write operation.

3. A display device comprising the control device recited in claim 1.

4. A control device comprising:

a writing device that writes an image according to image data to a plurality of pixels that compose a display section, each of the plurality of pixels being given one of a plurality of display states including at least a first display state and a second display state by writing performed by the writing device;

a specifying device that specifies a group of pixels that is subject to refreshing among the plurality of pixels; and

a refresh processing device that performs refreshing for the group of pixels when a count determined since the last refreshing is equal to or greater than a threshold value,

wherein the threshold value is representative of a predetermined count representing the number of pixels with which writing is performed among the group of pixels specified by the specifying device from the first display state to the second display state, and the number of pixels with which writing is performed among the group of pixels specified by the specifying device from the second display state to the first display state,

wherein, while the refresh processing device is performing refreshing, the writing device does not perform image writing with respect to the group of pixels that is subject to the refreshing, but performs image writing with respect to a group of pixels that is not subject to the refreshing.

5. A control device comprising:

a writing device that writes an image according to image data to a plurality of pixels that compose a display section, each of the plurality of pixels being given one of a plurality of display states including at least a first display state and a second display state by writing performed by the writing device;

a specifying device that specifies a group of pixels that is subject to refreshing among the plurality of pixels; and

a refresh processing device that performs refreshing for the group of pixels when a count determined since the last refreshing is equal to or greater than a threshold value,

wherein the threshold value is representative of a predetermined count representing the number of pixels with which writing is performed among the group of pixels specified by the specifying device from the first display state to the second display state, the number of pixels with which writing is performed among the group of pixels specified by the specifying device from the second display state to the first display state, the number of pixels with which overwriting is performed among the group of pixels specified by the specifying device from the first display state to the first display state, and the number of pixels with which overwriting is performed among the group of pixels specified by the specifying device from the second display state to the second display state,

wherein, while the refresh processing device is performing refreshing, the writing device does not perform image writing with respect to the group of pixels that is subject to the refreshing, but performs image writing with respect to a group of pixels that is not subject to the refreshing.

6. A control method for a display device equipped with a display section composed of a plurality of pixels, the control method comprising:

a specifying step of specifying a group of pixels that is subject to refreshing among the plurality of pixels, each of the plurality of pixels assuming one of a plurality of display states including at least a first display state and a second display state;

a refresh processing step of refreshing the group of pixels when a count of the number of times of image writing according to image data with respect to the group of pixels specified by the specifying step since the last refreshing is equal to or greater than a threshold value,

wherein the threshold value is representative of a predetermined count representing the number of times that writing is performed, with respect to at least one pixel among the specified group of pixels, from the first display state to the second display state, and the number of times that writing is performed, with respect to at least one pixel among the specified group of pixels, from the second display state to the first display state; and

a writing step of, while the refresh processing step is performing refreshing, not performing image writing according to image data with respect to the group of pixels that is subject to the refreshing, but performing image writing according to image data with respect to a group of pixels that is not subject to the refreshing.