Electro-optic device and electronic instrument

• US 7,605,798 B2
• Filed: 01/13/2006
• Issued: 10/20/2009
• Est. Priority Date: 02/21/2005
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Komatsu, Yuko
• Primary Examiner(s): Dharia; Prabodh M
• Application Number:
  US11/332,869
• Publication Number:
  US 20060187189A1
• Time in Patent Office: 1,376 Days
• Field of Search: 345/89, 345/90, 345 96- 98, 345/100, 345/103, 345/107, 345/208, 345/209, 359/566, 359/569, 359/35, 359/296, 347/239, 385/16, 385/130, 385/142, 349/201
• US Class Current: 345/107
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1676 Electrodes
• CPC Class Codes: G02F 1/16766 for active matrices
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• 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

An electro-optic device includes spaced apart pixel electrodes in respective unit areas arranged in a plane defined by dividing the plane into common shapes without gaps, and an electro-optic layer facing the pixel electrodes. In response to an applied first electric potential to the pixel electrodes, the electro-optic layer expresses a first grayscale, and in response to an applied second electric potential, it expresses a second grayscale. The distance between adjacent pixel electrodes is selected so that a boundary between an area expressing the first grayscale and an area expressing the second grayscale is substantially identical to a boundary between the unit area provided with one of the adjacent pixel electrodes and the unit area provided with another of the adjacent pixel electrodes.

Claims

1. An electro-optic device, comprising:

a plurality of pixel electrodes each formed for respective unit areas with a distance between one of the pixel electrodes and another of the pixel electrodes adjacent to the one of the pixel electrodes, the unit areas being arranged in a plane and defined by dividing the plane into the same shapes without a gap; and

an electro-optic layer that faces each of the pixel electrodes, and in response to application of a first electric potential to each of the pixel electrodes, expresses a first grayscale in an area corresponding to each of the pixel electrodes, in response to application of a second electric potential different form the first electrical potential to each of the pixel electrodes, expresses a second grayscale different from the first grayscale in an area corresponding to each of the pixel electrodes,

wherein the distance between one of the pixel electrodes and another of the pixel electrodes adjacent to the one of the pixel electrodes is selected so that a boundary between an area expressing the first grayscale in response to application of the first electric potential to the one of the pixel electrodes and an area expressing the second grayscale in response to application of the second electric potential to the another of the pixel electrodes adjacent to the one of the pixel electrodes is substantially identical to a boundary between the unit area provided with the one of the pixel electrodes and the unit area provided with the another of the pixel electrodes.

2. The electro-optic device according to claim 1, wherein

the electro-optic layer includes charged particles and a dispersion medium dispersing the charged particles.

3. An electronic instrument comprising the electro-optic device according to claim 1.

4. An electro-optic device comprising:

a plurality of pixel electrodes arranged in a plane with a distance from an adjacent one of the pixel electrodes; and

an electro-optic layer that faces each of the pixel electrodes, and in response to application of a first electric potential to each of the pixel electrodes, expresses a first grayscale in an area corresponding to each of the pixel electrodes, in response to application of a second electric potential different form the first electrical potential to each of the pixel electrodes, expresses a second grayscale different from the first grayscale in an area corresponding to each of the pixel electrodes,

wherein the distance from an adjacent one of the pixel electrodes is selected so that a boundary between an area expressing the first grayscale in response to application of the first electric potential to one of the pixel electrodes and an area expressing the second grayscale in response to application of the second electric potential to another of the pixel electrodes adjacent to the one of the pixel electrodes is substantially identical to a boundary between an area expressing the second grayscale in response to application of the second electric potential to the one of the pixel electrodes and an area expressing the first grayscale in response to application of the first electric potential to the another of the pixel electrodes adjacent to the one of the pixel electrodes.

5. An electro-optic device, comprising:

a plurality of unit electrode group each including a predetermined number of pixel electrodes arranged in a plane with a distance from an adjacent one of the pixel electrodes; and

an electro-optic layer that faces each of the pixel electrodes, and in response to application of a first electric potential to each of the pixel electrodes, expresses a first grayscale in an area corresponding to each of the pixel electrodes, in response to application of a second electric potential different form the first electrical potential to each of the pixel electrodes, expresses a second grayscale different from the first grayscale in an area corresponding to each of the pixel electrodes,

wherein the first grayscale, the second grayscale, and a intermediate grayscale between the first grayscale and the second grayscale are expressed for each of the unit electrode groups by applying the first electric potential to the number of pixel electrodes out of the predetermined number of the pixel electrodes forming the unit electrode group corresponding to a grayscale value designated to the unit electrode group while applying the second electric potential to the remaining pixel electrodes in the unit electrode group, and

the distance from an adjacent one of the pixel electrodes is selected so that the whole of one of the unit electrode groups including the pixel electrodes and a gap between the pixel electrodes expresses the first grayscale in response to designation of specific grayscale to the one of the unit electrode groups, and a ratio of the total area expressing the first grayscale and the total area expressing the second grayscale is in proportion to the grayscale value designated to the one of the unit electrode groups.

6. An electro-optic device, comprising:

a plurality of pixel electrodes arranged in a matrix, the plurality of pixel electrodes including a first pixel electrode and a second pixel electrode disposed adjacent to each other, a space being formed between the first pixel electrode and the second pixel electrode;

an electro-optic layer placed over the first pixel electrode, second pixel electrode and the space, the electro-optic layer including a plurality of charged particles; and

an opposed electrode placed over the electro-optic layer and facing the first pixel electrode, the second pixel electrode and the space,

wherein d/G is equal to or greater than 1/10, and is equal to or smaller than 3/10 when a distance between the first pixel electrode and the second pixel electrode is d, and a gap formed between the opposed electrode and at least one of the first pixel electrode and the second pixel electrode is G.

7. The electro-optic device according to claim 6,

wherein the electro-optic layer expresses a first grayscale in an area corresponding to one of the first pixel electrode and the second pixel electrode in response to application of a first electric potential to the one of the first pixel electrode and the second pixel electrode, and expresses a second grayscale different from the first grayscale in an area corresponding to one of the first pixel electrode and the second pixel electrode in response to application of a second electric potential different from the first electrical potential to the one of the first pixel electrode and the second pixel electrode, and

wherein a boundary between an area expressing the first grayscale in response to application of the first electric potential to the first pixel electrode and an area expressing the second grayscale in response to application of the second electric potential to the second pixel electrode is substantially identical to a boundary between an area expressing the second grayscale in response to application of the second electric potential to the first pixel electrode and an area expressing the first grayscale in response to application of the first electric potential to the second pixel electrode.

8. The electro-optic device according to claim 6, wherein the electro optic layer includes a dispersion medium dispersing the charged particles.

9. An electronic instrument comprising the electro-optic device according to claim 6.