Display medium driving method

• US 20020033784A1
• Filed: 09/06/2001
• Published: 03/21/2002
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Machida, Yoshinori, Shigehiro, Kiyoshi, Sakamaki, Motohiko, Matsunaga, Takeshi, Yamaguchi, Yoshiro
• Granted Patent: US 7,230,604 B2
• Time in Patent Office: Days
• US Class Current: 345/84
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• 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 drive method for a display medium containing two particle types can drive the display medium with a low voltage and thereby achieve high image resolution, downsize the drive circuit, and lower the cost while improving the durability of the display medium. The display medium has a pair of substrates, at least one of which is transparent, disposed with a gap therebetween, and two types of particles of different color and charge characteristics sealed between the pair of substrates. To change the displayed image, the drive method applies a voltage pulse to at least one of the pair of substrates to pull particles that are to move to the substrate to which the particles that are to move adhere, and then applies a voltage pulse to move the particles that are to move to the substrate opposite the substrate to which the particles that are to move adhere.

Claims

1. A drive method for a display medium comprising a pair of substrates, at least one of which is transparent, disposed with a gap therebetween, and two types of particles of different color and charge characteristics sealed between the pair of substrates, the method comprising the steps of:

applying a voltage pulse to at least one of the pair of substrates to pull particles that are to move to the substrate to which the particles that are to move adhere when changing an image displayed on the madium; and

applying a voltage pulse to move the particles that are to move to the substrate opposite to the substrate to which the particles that are to move adhere, thereby changing a displayed image.

2. The display medium drive method as described in claim 1, wherein a total voltage pulse apply time in a cycle for applying a voltage pulse to at least one of the pair of substrates to pull the particles that are to move to the substrate to which the particles that are to move adhere, and then applying a voltage pulse to move the particles that are to move to the substrate opposite to the substrate to which the particles that are to move adhere, is 0.1 msec to 40 msec.

3. The display medium drive method as described in claim 1, wherein the cycle for applying a voltage pulse to at least one of the pair of substrates to pull particles that are to move to the substrate to which the particles that are to move adhere, and then applying a voltage pulse to move the particles that are to move to the substrate opposite to the substrate to which the particles that are to move adhere, is performed two or more times.

4. The drive method for a display medium comprising a transparent display substrate, a back substrate opposite the display substrate with a gap therebetween, and two types of particles of different color and charge characteristics sealed between the display substrate and back substrate, the method comprising the steps of:

applying a voltage pulse to the display substrate and back substrate to move particles adhering to the back substrate toward the display substrate when changing an image displayed on the medium; and

applying next a voltage pulse to move particles, which moved for pixels other than pixels for which particles should move, to the back substrate.

5. The display medium drive method as described in claim 4, wherein a cycle for applying a voltage pulse to the display substrate and back substrate to move particles adhering to the back substrate toward the display substrate, and then applying a voltage pulse to move particles, which moved for pixels other than pixels for which particles should move, to the back substrate, is performed two or more times.

6. A drive method for a display medium comprising a pair of substrates, at least one of which is transparent, disposed with a gap therebetween, and two types of particles of different color and charge characteristics sealed between the pair of substrates, the method comprising the step of:

applying a voltage pulse gradually increasing from a start voltage to a peak voltage to at least one of the pair of substrates.

7. The display medium drive method as described in claim 6, wherein the voltage pulse is applied two or more times.

8. A drive method for a display medium comprising a pair of substrates, at least one of which is transparent, disposed with a gap therebetween, and two types of particles of different color and charge characteristics sealed between the pair of substrates, the method comprising the step of:

applying a rectangular wave voltage pulse two or more times with a pulse width of 0.1 msec to 20 msec to at least one of the pair of substrates.