Optical switching element and photoaddressable display medium using the same

• US 20040105614A1
• Filed: 08/12/2003
• Published: 06/03/2004
• Est. Priority Date: 11/29/2002
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Hikichi, Takehito, Kobayashi, Hideo
• Granted Patent: US 7,903,324 B2
• Time in Patent Office: Days
• US Class Current: 385/16
• CPC Class Codes: G02F 1/1354 having a particular photoconducting structure or material

Abstract

An optical switching element including at least a multi-layered optical switching layer that includes a charge generation layer and a charge transport layer wherein, the charge transport layer contains a charge transporting material represented by the following general formula (1). The optical switching element is applicable in a device, a photoaddressable display medium and a display device. The optical switching element may alternatively include a mono-layered optical switching layer that has a charge generating function and a charge transporting function, wherein the mono-layered optical switching layer contains the charge transporting material represented by the following general formula (1).

Claims

1. An optical switching element, comprising:

a multi-layered optical switching layer that contains a charge generation layer and a charge transport layer;

or

a mono-layered optical switching layer that has a charge generating function and a charge transporting function,

wherein the charge transport layer or the mono-layered optical switching layer contains a charge transporting material represented by the following general formula (1);

 

wherein R¹ and R³ each independently represent CH₃ or C₂H₅, and R² and R⁴ each independently represent H, CH₃ or C₂H₅.

2. The optical switching element of claim 1, wherein the charge transporting material is contained in the charge transport layer at a concentration of 30% to 90% by weight.

3. The optical switching element of claim 1, wherein the charge transporting material is contained in the charge transport layer at a concentration of 45% to 80% by weight.

4. The optical switching element of claim 1, wherein the charge transporting material is contained in the charge transport layer at a concentration of 50% to 70% by weight.

5. A device, comprising:

the optical switching element of claim 1;

and

a functional element electrically connected to the optical switching element.

6. A photoaddressable display medium, comprising:

a pair of electrodes, at least one of which has optical transparency;

the optical switching element of claim 1;

and

a display element including a display layer having a memory effect, wherein

the optical switching element and the display element are laminated between the pair of electrodes.

7. The photoaddressable display medium of claim 6, wherein the display element is a color display element having a plurality of display layers, and each of the plurality of display layers is a cholesteric liquid crystal display layer that selectively reflects visible light beams of a color that is different from the color of the visible light beams selectively reflected by any other one of the plurality of display layers.

8. A display device, comprising:

the photoaddressable display medium of claim 7;

a unit for driving the display medium; and

a unit for optically writing to the display medium.

9. The optical switching element of claim 1, wherein the charge transporting material represented by general formula (1) is a charge transporting material represented by the following general formula (2):

10. A device, comprising:

the optical switching element of claim 9;

and

a functional element electrically connected to the optical switching element.

11. A photoaddressable display medium, comprising:

a pair of electrodes, at least one of which has optical transparency;

the optical switching element of claim 9;

and

a display element including a display layer having a memory effect, wherein

the optical switching element and the display element are laminated between the pair of electrodes.

12. The photoaddressable display medium of claim 11, wherein the display element is a color display element having a plurality of display layers, and each of the plurality of display layers is a cholesteric liquid crystal display layer that selectively reflects visible light beams of a color that is different from the color of the visible light beams selectively reflected by any other one of the plurality of display layers.

13. A display device, comprising:

the photoaddressable display medium of claim 12;

a unit for driving the display medium; and

a unit for optically writing to the display medium.

14. The optical switching element of claim 9, wherein R¹ and R³ each represent CH₃, and R² and R⁴ each represent C₂H₅.

15. A device, comprising:

the optical switching element of claim 14;

and

a functional element electrically connected to the optical switching element.

16. A photoaddressable display medium, comprising:

a pair of electrodes, at least one of which has optical transparency;

the optical switching element of claim 14;

and

a display element including a display layer having a memory effect, wherein

the optical switching element and the display element are laminated between the pair of electrodes.

17. The photoaddressable display medium of claim 16, wherein the display element is a color display element having a plurality of display layers, and each of the plurality of display layers is a cholesteric liquid crystal display layer that selectively reflects visible light beams of a color that is different from the color of the visible light beams selectively reflected by any other one of the plurality of display layers.

18. A display device, comprising:

the photoaddressable display medium of claim 17;

a unit for driving the display medium; and

a unit for optically writing to the display medium.