Development process and apparatus

• US 4,368,970 A
• Filed: 09/21/1981
• Issued: 01/18/1983
• Est. Priority Date: 06/02/1980
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Hays, Dan A.
• Primary Examiner(s): Prescott, A. C.
• Application Number:
  US06/304,528
• Time in Patent Office: 484 Days
• Field of Search: 355/3 DD, 355/14 D, 355/16, 355/3 BE, 118/656, 118/651, 118/649, 118/657, 118/658, 430/122
• US Class Current: 399/167
• CPC Class Codes: G03G 15/09 using magnetic brush

Abstract

The present invention is directed to an electrostatographic imaging apparatus, and an electrostatographic imaging method utilizing such apparatus, wherein the apparatus is comprised of an imaging means, a charging means, an exposure means, a development means, and a fixing means, the improvement residing in the development means comprising in operative relationship a tensioned deflected flexible imaging means; a transporting means; a development zone situated between the imaging means and the transporting means; the development zone containing therein electrically insulating toner particles, and electrically insulating magnetic carrier particles, means for causing the flexible imaging means for causing the transporting member to move at a speed of from about 5 cm/sec, to about 50 cm/sec; means to move at a speed of from about 6 cm/sec to about 100 cm/sec, the means for imaging and the means for transporting moving at different speeds; and the means for imaging and the means for transporting having a distance therebetween of from about 0.05 millimeters to about 1.5 millimeters.

Claims

1. An electrostatographic imaging apparatus comprised of an imaging means, a charging means, an exposure means, a development means, and a fixing means, the improvement residing in the development means comprising in operative relationship a tensioned deflected flexible imaging means;

a transporting means;

a development zone situated between the imaging means and the transporting means;

the development zone containing therein electrically insulating toner particles, and electrically insulating magnetic carrier particles, means for causing the flexible imaging means to move at a speed of from about 5 cm/sec, to about 50 cm/sec, means for causing the transporting means to move at a speed of from about 6 cm/sec to about 100 cm/sec, the means for imaging and the means for transporting moving at different speeds; and

the means for imaging and the means for transporting having a distance therebetween of from about 0.05 millimeters to about 1.5 millimeters.

2. An electrostatographic imaging apparatus in accordance with claim 1 wherein there is further included in the development means, means for introducing a high electric field.

3. An electrostatographic imaging apparatus in accordance with claim 2 wherein the electrically insulating toner particles migrate from the electrically insulating magnetic particles in the direction of the deflected flexible imaging member, said migration resulting from the rotation of the electrically insulating carrier particles in one direction, and subsequently in another direction, whereby the electrically insulating toner particles are made continuously available immediately adjacent to the deflected flexible imaging means.

4. An electrostatographic imaging apparatus in accordance with claim 2 wherein said flexible imaging member means is deflected in an arc of from about 10 degrees to about 50 degrees.

5. An electrostatographic imaging apparatus in accordance with claim 2 wherein the tensioned deflected flexible imaging member and transporting member are moving in the same direction or in an opposite direction.

6. An electrostatographic imaging apparatus in accordance with claim 2 wherein the distance between the deflected flexible imaging member means and the transporting member means ranges from about 0.04 millimeters to about 1 millimeter, and the development zone length ranges from about 1 centimeter to about 2 centimeters.

7. An electrostatographic imaging apparatus in accordance with claim 2 wherein the electrically insulating toner particles contained in the developer composition are charged positively, and the electrically insulating magnetic carrier particles contained in the developer composition are charged negatively, and the flexible imaging member is charged negatively.

8. An electrostatographic imaging apparatus in accordance with claim 7 wherein there is added thereto a charge control additive for the purpose of imparting a positive charge to the toner resin.

9. An electrostatographic imaging apparatus in accordance with claim 8 wherein the charge control additive is a quaternary ammonium compound or an alkyl pyridinium halide.

10. An electrostatographic imaging apparatus in accordance with claim 2 wherein the deflected flexible imaging member is comprised of a photoresponsive member containing a substrate, a hole injecting layer, a hole transport layer, a charge generating layer, and an overcoated layer of an electrically insulating organic resin.

11. An electrostatographic imaging appartus in accordance with claim 2 wherein the deflected flexible imaging member contains a substrate, a charge generating layer, and a hole transport layer.

17. An electrostatographic imaging apparatus in accordance with claim 1 wherein there is further included an idler roller.

12. An electrostatographic imaging apparatus comprised in operative relationship of a tensioned deflected flexible imaging member, a transporting roller means containing magnets therein attached to the transporting roller core, said roller containing thereon insulative developer particles comprised of electrically insulating toner particles, and electrically insulating magnetic carrier particles, whereby toner particles are transferred to the deflected flexible imaging member with the further provision that there is provided a low magnetic field means in a development zone encompassed by the deflected flexible imaging member, and the transporting roller means, and high magnetic fields at the entrance and exit regions of said development zone.

13. An electrostatographic imaging apparatus in accordance with claim 12, wherein the tensioned deflected flexible imaging members is in an arc of from about 10 degrees to about 50 degrees.

14. An electrostatographic imaging apparatus in accordance with claim 12 wherein the deflected flexible imaging member is comprised of a substrate, a hole injecting layer, a hole transport layer, a charge generating layer, and an overcoated layer of an electrically insulating organic resin.

15. An electrostatographic imaging apparatus in accordance with claim 12 wherein the deflected flexible imaging member is comprised of a substrate, a hole transport layer, and a charge generating layer.

16. An electrostatographic imaging apparatus in accordance with claim 12 wherein there is maintained a distance of from about 0.05 millimeters to about 1.5 millimeters between the deflected flexible imaging member and the transporting roller.

20. An electrostatographic imaging member in accordance with claim 12 wherein the deflected flexible imaging member is comprised of a substrate, a hole injecting layer, a hole transport layer, a charge generating layer, and an overcoating layer of an insulating organic resin.

18. An electrostatographic imaging method which comprises forming an electrostatic image on a tensioned deflected flexible imaging member contained in an electrostatographic imaging apparatus comprised of an imaging means, a charging means, an exposure means, a development means, a transfer means, and a fixing means, the improvement residing in the development means comprised in operative relationship of a deflected flexible imaging means, and a transporting means, means for causing the transporting means to move at a speed of from about 6 cm/sec to about 100 cm/sec, means for causing the deflected flexible imaging member means to move at a speed of from about 5 cm/sec to about 50 cm/sec, the means for transporting and the means for imaging moving at different speeds, said deflected flexible imaging member means and said transporting means having a distance therebetween of from about 0.05 millimeters to about 1.5 millimeters, the deflection of the flexible imaging member means caused by electrically insulating developer particles comprised of electrically insulating toner particles, and electrically insulating magnetic carrier particles situated in a development zone encompassed by said deflected flexible imaging member means, and said transporting means, said deflection and said relative movement of the deflected flexible imaging member means and transporting means providing sufficient force so as to cause agitation of said developer particles, means for introducing a high electric field into the development means, wherein said electrically insulating toner particles migrate from said electrically insulating magnetic carrier particles, the migration being in the direction of the deflected flexible imaging member means, said migration resulting from the rotation of the electrically insulating carrier particles in one direction and subsequently in another direction, whereby said electrically insulator toner particles are made continuously available immediately adjacent the deflected flexible imaging member means, and wherein agitation and the presence of an electrical field in a development zone causes toner particles to migrate and deposit on the electrostatic latent image, followed by transferring the developed image to a substrate, and permanently fixing the image thereto.

19. A method of imaging in accordance with claim 18 wherein the deflected flexible imaging member is in an arc of from about 10 degrees to about 50 degrees.

21. An electrostatographic imaging method in accordance with claim 18 wherein deflected flexible imaging member is comprised of a substrate, a hole transport layer, and a charge generating layer.

22. An electrosatographic imaging method in accordance with claim 18 wherein the deflected flexible imaging member and transporting member are moving in the same direction, or said members are moving in opposite directions.

23. An electrostatographic imaging method in accordance with claim 18 wherein the toner particles are comprised of a styrene butylmethacrylate copolymer resin, and carbon black.

24. An electrostatographic imaging method in accordance with claim 18 wherein there is added to the developer composition a charge enhancing additive.

25. An electrostatographic imaging method in accordance with claim 24 wherein the charge enhancing additive is a quaternary ammonium compound, or an alkyl pyridinium halide.