Display unit, display device, and method for manufacturing the display device

• US 20020050784A1
• Filed: 10/31/2001
• Published: 05/02/2002
• Est. Priority Date: 11/01/2000
• Status: Active Grant

• Current Assignee: OJI Paper Company Limited (Oji Holdings Corporation)
• Original Assignee: OJI Paper Company Limited (Oji Holdings Corporation)
• Inventors: Maeda, Shuichi
• Granted Patent: US 6,864,865 B2
• Time in Patent Office: Days
• US Class Current: 313/495
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

A display unit includes a transparent hollow tube member and at least one display element sealed in the transparent hollow tube member. The display element is capable of rotating independently in the hollow tube member. Also, the display element has a surface which is divided into a plurality of areas having different colors and is polarized to have at least two poles having a different electrification state. An image formed by a display device including the display units is kind to the eye in the same way as printed matter, and does not cause eyestrain due to flickering of emitted light.

Claims

1. A display unit, comprising:

a transparent hollow tube member; and

at least one display element sealed in said transparent hollow tube member, said display element being capable of rotating independently, wherein

said display element has a surface which is divided into a plurality of areas having different colors, and

said display element is polarized to have at least two poles having a different electrification state.

2. A display unit as set forth in claim 1, wherein

the shape of said display element is selected from the group consisting of a sphere, oval, and cylinder.

3. A display unit as set forth in claim 1, further comprising:

a liquid which is sealed in said hollow tube member, said liquid being present between said display element and said hollow tube member.

4. A display device comprising a display unit as claimed in claim 1, wherein

a plurality of said display units is arranged over substantially the entire display region of said display device.

5. A display device as set forth in claim 4, wherein

substantially all of said plurality of display units are arranged so as to be substantially parallel to each other.

6. A display device as set forth in claim 4, further comprising:

an electric field application device which applies an electric field to said display unit.

7. A method for displaying colors on a display by using a display device as claimed in claim 6, comprising the step of:

applying an electric field corresponding to an image signal to said display element.

8. A method for producing a display device including at least one display unit, comprising the steps of:

forming a hollow tube member;

introducing a liquid in which display elements have been dispersed into said hollow tube member;

sealing an end portion of said hollow tube member to form a display unit comprising said hollow tube member in which said display element is contained; and

arranging said display unit over a display region of said display device.

9. A method for producing a display device as set forth in claim 8, wherein

the specific gravity of said liquid is close to the specific gravity of said display element.

10. A method for producing a display device as set forth in claim 8, wherein

said liquid is of a two-liquid system formed by combining a first liquid having higher specific gravity than that of said display element and a second liquid having lower specific gravity than that of said display element.

11. A method for producing a display device as set forth in claim 8, wherein said hollow tube member is formed by a method comprising the steps of:

forming a fiber having a two-layer structure; and

removing an inner layer of said fiber to produce said hollow tube member.

12. A method for producing a display device as set forth in claim 11 wherein said inner layer of said fiber is made of a material which may be dissolved in a solvent.

14. A method for producing a display device as set forth in claim 13 wherein said intermediate layer is dissolved by a solvent or by an irradiation of light.

15. A method for producing a display device as set forth in claim 13 wherein

the specific gravity of said intermediate layer, after being dissolved, is substantially the same as the specific gravity of said display element.

16. A method for producing a display device as set forth in claim 13 wherein

said display element of said display unit is cut by using a laser beam, a rotary knife, or a straight knife.

13. A method for producing a display device including at least one display unit, comprising the steps of:

forming a fiber having a three-layer structure, an intermediate layer of said fiber being formed by a material to be dissolved;

dissolving said intermediate layer of said fiber;

sealing an end portion of said fiber to form a display unit comprising the innermost layer of said fiber freely rotatable in the outermost layer of said fiber; and

arranging said display unit over a display region of said display device, wherein said innermost layer of said fiber functions as a display element and said outermost layer of said fiber functions as a hollow tube member.