Claims
- 1. DC pin scorotron charging apparatus for charging a photoreceptor to a final voltage, the DC pin scorotron charging apparatus comprising a first DC pin scorotron charging device for initially charging the photoreceptor to an intermediate overshoot voltage and a second DC pin scorotron charging device for thereafter uniformly charging the photoreceptor to the final voltage, the first DC pin scorotron charging device comprising a first control grid with a first grid percent open area that is generally high, the second DC pin scorotron charging device comprising a second control grid with a second grid percent open area that is generally low.
- 2. The DC pin scorotron charging apparatus of claim 1, the first grid percent open area being at or above 70 percent.
- 3. The DC pin scorotron charging apparatus of claim 1, the second grid percent open area being less than 70 percent.
- 4. The DC pin scorotron charging apparatus of claim 1, wherein the first DC pin scorotron charging device acts as a high-slope device and has a high intermediate overshoot voltage and is used to charge-up the photoreceptor to the intermediate overshoot voltage that is close to the target final voltage.
- 5. The DC pin scorotron charging apparatus of claim 1, wherein the second DC pin charging device has a low slope with a low overshoot and is used to charge the photoreceptor up slightly to the final voltage while leveling any charging non-uniformity.
- 6. DC pin scorotron charging apparatus for charging a photoreceptor to a final voltage, the DC pin scorotron charging apparatus comprising a first DC pin scorotron charging device for initially charging the photoreceptor to an intermediate overshoot voltage and a second DC pin scorotron charging device for thereafter uniformly charging the photoreceptor to the final voltage, the first DC pin scorotron charging device comprising a first control grid with a first grid percent open area that is generally high, the second DC pin scorotron charging device comprising a second control grid with a second grid percent open area that is generally low, the first DC pin scorotron charging device comprising a first charge-generating emitter with a first emitter dl/dV (“slope”) that is generally high, the second DC pin scorotron charging device comprising a second charge-generating emitter with a second emitter slope that is generally low.
- 7. The DC pin scorotron charging apparatus of claim 6, the first emitter slope exceeding 2.0 micro-Ampere per volt-meter.
- 8. The DC pin scorotron charging apparatus of claim 6, the second emitter slope being less than 2.0 micro-Ampere per volt-meter.
- 9. The DC pin scorotron charging apparatus of claim 6, the distance between the first and second control grids' surfaces and the photoreceptor surface being maintained at a constant value of about 1.5-2.0 mm.
- 10. The DC pin scorotron charging apparatus of claim 6, the first charge-generating emitter comprising a first pair of pin arrays, each pin thereof emitting a first pin current that is generally high, the second charge-generating emitter comprising a second pair of pin arrays, each pin thereof emitting a second pin current that is generally low.
- 11. The DC pin scorotron charging apparatus of claim 10, the first pin current being greater than 7.5 micro-Ampere per pin.
- 12. The DC pin scorotron charging apparatus of claim 10, the second pin current being equal to or less than 7.5 micro-Ampere per pin.
- 13. The DC pin scorotron charging apparatus of claim 6, wherein the first DC pin scorotron charging device acts as a high-slope device and has a high intermediate overshoot voltage and is used to charge-up the photoreceptor to the intermediate overshoot voltage that is close to the target final voltage.
- 14. The DC pin scorotron charging apparatus of claim 6, wherein the second DC pin charging device has a low slope with a low overshoot and is used to charge the photoreceptor up slightly to the final voltage while leveling any charging non-uniformity.
- 15. A printing machine comprising DC pin scorotron charging apparatus for charging a photoreceptor to a final voltage, the DC pin scorotron charging apparatus comprising a first DC pin scorotron charging device for initially charging the photoreceptor to an intermediate overshoot voltage and a second DC pin scorotron charging device for thereafter uniformly charging the photoreceptor to the final voltage, the first DC pin scorotron charging device comprising a first control grid with a first grid percent open area that is generally high, the second DC pin scorotron charging device comprising a second control grid with a second grid percent open area that is generally low.
- 16. The printing machine of claim 15, the first grid percent open area being at or above 70 percent.
- 17. The printing machine of claim 15, the second grid percent open area being less than 70 percent.
- 18. The printing machine of claim 15, wherein the first DC pin scorotron charging device acts as a high-slope device and has a high intermediate overshoot voltage and is used to charge-up the photoreceptor to the intermediate overshoot voltage that is close to the target final voltage.
- 19. The printing machine of claim 15, wherein the second DC pin charging device has a low slope with a low overshoot and is used to charge the photoreceptor up slightly to the final voltage while leveling any charging non-uniformity.
- 20. A printing machine comprising DC pin scorotron charging apparatus for charging a photoreceptor to a final voltage, the DC pin scorotron charging apparatus comprising a first DC pin scorotron charging device for initially charging the photoreceptor to an intermediate overshoot voltage and a second DC pin scorotron charging device for thereafter uniformly charging the photoreceptor to the final voltage, the first DC pin scorotron charging device comprising a first control grid with a first grid percent open area that is generally high, the second DC pin scorotron charging device comprising a second control grid with a second grid percent open area that is generally low, the first DC pin scorotron charging device comprising a first charge-generating emitter with a first emitter dl/dV (“slope”) that is generally high, the second DC pin scorotron charging device comprising a second charge-generating emitter with a second emitter slope that is generally low.
- 21. The printing machine of claim 20, the first emitter slope exceeding 2.0 micro-Ampere per volt-meter.
- 22. The printing machine of claim 20, the second emitter slope being less than 2.0 micro-Ampere per volt-meter.
- 23. The printing machine of claim 20, the distance between the first and second control grids' surfaces and the photoreceptor surface being maintained at a constant value of about 1.5-2.0 mm.
- 24. The printing machine of claim 20, the first charge-generating emitter comprising a first pair of pin arrays, each pin thereof emitting a first pin current that is generally high, the second charge-generating emitter comprising a second pair of pin arrays, each pin thereof emitting a second pin current that is generally low.
- 25. The printing machine of claim 24, the first pin current being greater than 7.5 micro-Ampere per pin.
- 26. The printing machine of claim 24, the second pin current being equal to or less than 7.5 micro-Ampere per pin.
- 27. The printing machine of claim 20, wherein the first DC pin scorotron charging device acts as a high-slope device and has a high intermediate overshoot voltage and is used to charge-up the photoreceptor to the intermediate overshoot voltage that is close to the target final voltage.
- 28. The printing machine of claim 20, wherein the second DC pin charging device has a low slope with a low overshoot and is used to charge the photoreceptor up slightly to the final voltage while leveling any charging non-uniformity.
INCORPORATION BY REFERENCE OF ANOTHER U.S. PATENT
The applicant hereby incorporates by reference the disclosure of U.S. Pat. No. 4,725,732 to Joseph H. Lang et al., entitled “Pin corotron and scorotron assembly,” issued Feb. 16, 1988, verbatim and with the same effect as though such disclosure were fully and completely set forth herein.
The applicant hereby incorporates by reference the disclosure of U.S. Pat. No. 5,537,198 to Mark S. Jackson, “Double split recharge method and apparatus for color image formation,” issued Dec. 12, 1994, verbatim and with the same effect as though such disclosure were fully and completely set forth herein.
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