Method and apparatus for determining toner level in electrophotographic print engines

• US 7,301,665 B2
• Filed: 05/02/2005
• Issued: 11/27/2007
• Est. Priority Date: 08/07/1995
• Status: Expired due to Term

• Current Assignee: T/R Systems, Inc. (Electronics For Imaging Incorporated)
• Original Assignee: Electronics For Imaging Incorporated
• Inventors: Rowe, Francis A., Zuber, Peter A., Barry, Michael W., Bartholmae, Jack N., Tompkins, E. Neal
• Primary Examiner(s): Lamb; Twyler
• Assistant Examiner(s): Milia; Mark R.
• Application Number:
  US11/120,006
• Publication Number:
  US 20050206933A1
• Time in Patent Office: 939 Days
• Field of Search: 358/1.15, 358/1.5, 358/1.9, 347/5, 347/7
• US Class Current: 358/1.15
• CPC Class Codes: G03G 13/08 using a solid developer, e.g. powder developer
• CPC Class Codes: G03G 15/0856 Detection or control means for the developer level
• CPC Class Codes: G03G 15/5087 for receiving image data
• CPC Class Codes: G03G 15/553 Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job
• CPC Class Codes: G03G 15/556 for toner consumption, e.g. pixel counting, toner coverage detection or toner density measurement
• CPC Class Codes: G03G 2215/0888 Arrangements for detecting toner level or concentration in the developing device
• CPC Class Codes: G06F 3/121 Facilitating exception or error detection and recovery, e.g. fault, media or consumables depleted
• CPC Class Codes: G06F 3/1235 caused by end of consumables, e.g. paper, ink, toner
• CPC Class Codes: G06F 3/1285 Remote printer device, e.g. being remote from client or server
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 15/12 by photographic printing , e.g. by laser printers
• CPC Class Codes: G06K 15/1823 for evaluating the resources needed, e.g. rasterizing time, ink, paper stock

Abstract

The toner in the toner cartridge is determined by taking each of the rasterized images output by the RIP and evaluating the pixel levels over the surface thereof. The average value is determined as a percentage of the maximum toner that can be applied to the page. This is then subtracted from a toner value and a remaining toner level determined. Further, all pages of the rasterized document can be evaluated to predetermine the toner level after printing. If this falls below a predetermined minimum, printing is inhibited for that document.

Claims

1. A method for printing a print job comprising a page, the page comprising a predetermined number of image pixels, each image pixel comprising a value between completely OFF to completely ON, the method comprising:

determining an initial amount of toner in a toner cartridge associated with a printer;

determining a maximum amount of toner required to print a page on the printer;

summing the pixel values to generate an accumulated pixel value;

dividing the accumulated pixel value by the predetermined number of image pixels to generate an average pixel value;

calculating an amount of toner required to print a print job on the printer by multiplying the average pixel value by the determined maximum toner amount; and

sending the print job to the printer for printing only if a difference between the calculated toner amount and the initial toner amount exceeds a minimum toner level.

2. The method of claim 1, further comprising sending a toner low command to a user if the difference is less than the minimum toner level.

3. The method of claim 1, further comprising sending the rasterized print job to an alternative printer if the difference is less than the minimum toner level.

4. The method of claim 1, wherein:

the image pixel values range from a minimum value to a maximum value; and

calculating comprises summing the image pixel values of all image pixels having values greater than the minimum value.

5. The method of claim 4, wherein the minimum value is zero.

6. The method of claim 4, wherein the maximum value is 255.

7. The method of claim 1, wherein calculating further comprises determining an average of substantially all pixel values of the rasterized print job.

8. The method of claim 7, further comprising calculating the average as a percentage of a black page.

9. The method of claim 8, further comprising multiplying the percentage by a maximum amount of toner required to print a black page.

10. Apparatus for printing a print job comprising a page, the page comprising a predetermined number of image pixels, each image pixel comprising a value between completely OFF to completely ON, the apparatus comprising:

means for determining an initial amount of toner in a toner cartridge associated with a printer;

means for determining a maximum amount of toner required to print a page on the printer;

means for summing the pixel values to generate an accumulated pixel value;

means for dividing the accumulated pixel value by the predetermined number of image pixels to generate an average pixel value;

means for calculating an amount of toner required to print a print job on the printer, wherein the means for calculating comprises means for multiplying the average pixel value by the determined maximum toner amount; and

means for sending the print job to the printer for printing only if a difference between the calculated toner amount and the initial toner amount exceeds a minimum toner level.

11. The apparatus of claim 10, further comprising means for sending a toner low command to a user if the difference is less than the minimum toner level.

12. The apparatus of claim 10, further comprising means for sending the rasterized print job to an alternative printer if the difference is less than the minimum toner level.

13. The apparatus of claim 10, wherein:

the image pixel values range from a minimum value to a maximum value; and

the means for calculating comprises means for summing the image pixel values of all image pixels having values greater than the minimum value.

14. The apparatus of claim 13, wherein the minimum value is zero.

15. The apparatus of claim 13, wherein the maximum value is 255.

16. The apparatus of claim 10, wherein the means for calculating further comprises means for determining an average of substantially all pixel values of the rasterized print job.

17. The apparatus of claim 16, further comprising means for calculating the average as a percentage of a black page.

18. The apparatus of claim 17, further comprising means for multiplying the percentage by a maximum amount of toner required to print a black page.