Granted Patent B2

US 7,817,929 · App. 12/240,572 · Granted Oct 19, 2010

Abstract

Claims (25)

1. A system for adjusting selected operating parameters of an image forming device to improve color registration based on selected environmental conditions, said system comprising:

a first image forming station to print a first registration mark on a substrate;

a second image forming station having a photoconductive unit, a charging unit and a developer unit cooperable together so as to at least partially erase the first registration mark printed on the substrate by said first image forming station to form a registration pattern in a reverse transfer process of the color registration performed at said second image forming station;

a sensor mechanism for measuring selected environmental conditions of dry-bulb temperature and relative humidity;

a control mechanism for reading said sensor mechanism to adjust the voltage biases of said charging and developer units of said second image forming station based on a wet-bulb temperature value so as to maintain a predetermined potential difference between charged and uncharged areas of said photoconductive unit of said second image forming station that avoids Paschen breakdown and the development of toner at charged areas of said photoconductive unit during the reverse transfer process of the color registration; and

a memory connected to and accessible by said control mechanism and having stored therein lists of correlated values comprising a list of wet-bulb temperature values related to values of dry-bulb temperature and relative humidity measured by said sensor mechanism correlated with lists of voltage values related to voltage biases of said charging and developer units to maintain the predetermined potential difference between the charged and uncharged areas of said photoconductive unit during the reverse transfer process of the color registration.

2. The system of claim 1 wherein said sensor mechanism is electrically connected to said control mechanism.

3. The system of claim 1 wherein said control mechanism includes a controller.

4. The system of claim 3 wherein said sensor mechanism is disposed adjacent to said controller.

5. The system of claim 4 wherein said lists of correlated values are stored in a lookup table in said memory.

6. The system of claim 3 wherein said control mechanism also includes a high voltage power supply electrically connected to said controller.

7. The system of claim 6 wherein said sensor mechanism is electrically connected to said controller.

8. The system of claim 6 wherein said high voltage power supply is interposed and electrically connected between said controller and said charging and developer units.

9. The system of claim 8 wherein said sensor mechanism is electrically connected to said controller.

10. The system of claim 9 wherein said lists of correlated values are stored in a lookup table in said memory.

11. The system of claim 10 wherein said sensor mechanism includes a sensor for measuring dry-bulb temperature disposed adjacent to said controller.

12. The system of claim 10 wherein sensor mechanism includes a sensor for measuring relative humidity disposed adjacent to said controller.

13. The system of claim 8 wherein said lists of correlated values are stored in a lookup table in said memory.

14. A method for adjusting selected operating parameters of an image forming device to improve color registration based on selected environmental conditions, said method comprising:

at a first image forming station printing a first registration mark on a substrate;

at a second image forming station at least partially erasing the first registration mark printed on the substrate by the first image forming station to form a registration pattern in a reverse transfer process of the color registration performed at the second image forming station;

sensing selected environmental conditions of dry-bulb temperature and relative humidity so as to determine wet-bulb temperature values correlated with said dry-bulb temperature and relative humidity; and

adjusting voltage biases of charging and developer units of the second image forming station based on the wet-bulb temperature value so as to maintain a predetermined potential difference between charged and uncharged areas of a photoconductive unit of the second image forming station that avoids Paschen breakdown and the development of toner at charged areas of the photoconductive unit during the reverse transfer process of the color registration.

15. The method of claim 14 further comprising storing a lookup table in memory containing lists of correlated values comprising a list of wet-bulb temperature values related to values of sensed dry-bulb temperature and relative humidity correlated with lists of voltage values related to voltage biases of said charging and developer units to maintain the predetermined potential difference between the charged and uncharged areas of the photoconductive unit during the reverse transfer process of the color registration.

16. The method of claim 15 further comprising accessing said lookup table from memory with a wet-bulb temperature value to determine a value of voltage biases to apply to said charging and developer units.

Assignments (8)