Solution: Consumable Usage Calculations Based on Usage Profile

INFORMATION

Phaser 7750 consumable life ratings are based on certain standard parameters, which are:

1. 5% coverage of each individual color (CMYK), in an 8” x 10” printed area, on letter or A4 size plain paper.
2. 4 prints per job (one PRINT is one side of an 8 ½” x 11” or A4 sized page).
3. The difference between PRINTS and SHEETS in usage profile:
   1. A SHEET is a physical piece of paper of any size and a PRINT is an 8” x 10” imaged area on a SHEET. A duplexed letter/A4 sized SHEET will have 2 PRINTS, 1 on each side. A B sized SHEET will have the equivalent imaged area of 2 PRINTS on each side; so a duplexed B sized SHEET will have 4 PRINTS of equivalent letter / A4 coverage.

Any variation in these parameters will affect the actual yield of all consumables. For example, jobs less than 4 prints can decrease Image Unit life (See Chart 1: Image Unit Life). Usage Profile can be used as an analysis tool to determine if a customer is achieving the rated life on their individual consumable.

CAUSE

Algorithms designed to maximize life, while providing defect free print quality, determine life ratings on consumables and CRUs’ (Customer Replaceable Units) according to the tables and graph below.

Table 1: Fuser Life Rating

Setting	Sizes or Sides	Decrement per Print Single-Sided	Decrement per Print Duplexed
Plain Paper / Letterhead	Letter or A4	1	2
Heavy Plain Paper	Letter or A4	1	2
Thin / Thick Cardstock & Photo Paper	Letter or A4	2	4
Phaser 45 Series Transparency	Letter or A4	2	N/A
Any of the types listed	A3 or B Size	2 times Letter or A4 rate	2 times Letter or A4 rate

Examining Table 1 (fuser life rating) shows that the absolute minimum fuser life will occur when duplexing B sized Thin/Thick Cardstock. Printing this type of job will decrement fuser life by 8 equivalent Letter/A4 size prints for every print made. Under these circumstances Fuser life would be 60,000 prints/8 pages per print or 7,500 prints. Swapping fusers can also severely degrade the reported life of any fuser because the printer makes an assumption about the amount of life left based on the configuration of the fuses. See the Phaser 7750 Service Manual for a complete comprehensive explanation of fuser fuses.

Table 2: Imaging unit Life Rating

Imaging Unit Algorithm	Rotation	Pixels Imaged
Life is determined by a combination of rotations and pixels printed. The factor that is dominant during the life of an Imaging Unit, rotations or pixels counted, will control life counting. (See Chart 1)	Imaging Unit rotations are counted on all units during color printing, black and white printing (when the printer is in Optimize for Speed mode) and when the printer is initializing in preparation for a print job.  When printing more than 10 black and white pages in a row, in the Optimize for Economy mode, the color imaging units are disengaged. In this mode the Imaging Units rotate and decrement at a significantly slower rate.  Jobs over 4 pages minimize the effects of rotations on life.	Print coverage higher than 5% per color generate higher pixel imaging counts. At higher densities, pixels imaged will be the dominant factor driving life counting. Rotations are the dominant driving factor with low toner coverage.

Toner Cartridge life is inversely proportional to the coverage rate As an example, the Cyan Cartridge is rated for 22,000 prints, at 5% coverage, in an 8” x 10” area of the page. When coverage is doubled to 10% toner cartridge life is cut in half, to 11,000 prints. You can quickly calculate the life based on the ratio of rated life at 5% compared to the percent coverage the customer is using. For example, at 20% coverage the life will be [5%/20%]*{22,000] or ¼ of its rated capacity, which is 5500 prints. So at 20% coverage, the expected life of a Color Toner (Cyan, Magenta, Yellow) Cartridge will be approximately 5500 prints. See chart 1 for more details.

From examining Chart 1 you can see that, as an extreme example, at 50% coverage, a toner cartridge will last for approximately 2200 Letter/A4 sized prints. However if a customer is making duplex prints on 11”x17” with 50% coverage, a Toner Cartridge would be consumed in 550 prints. 

WHAT TO DO

Print a Service Usage Profile from the Troubleshooting > Service Tools > Service Usage Profile; menu on the control panel. Careful examination of the Usage Profile by a knowledgeable reviewer will reveal many clues about a usage pattern and how consumable life is affected. See table 3 below for specific Usage Profile line items and the secrets they reveal.

 

Table 3: Usage Profile token secrets

Token #	Name	Information
108	Average Coverage%	Average coverage from print #1 to now
109	Coverage-Last 30 days %. From Pages 1 (calendar day, the first day of a month) to pages 31 (the 31st of the calendar month)	How much toner have they been using recently. If they are printing at high coverage rates, their toner cartridges won’t last as long.
141	1-sided vs. 2-sided sheets	2-sided sheets count for 2 prints.
143 144	MP Tray Media Cassette Tray Media	This will tell you how much plain paper, heavy plain paper, letterhead, thin/thick cardstock, photo paper, envelopes and transparencies have been through the fuser, which will degrade its life according to the algorithm in table 1.
162	Jobs by Document Length	This will tell you if a lot of 1-page jobs have been run or if the average job is more than 4 pages. Less than 4 page jobs will put more rotations on the Print Cartridges.
207	Imaging Unit Installation Date	This tells how many equivalent letter/A4 pages have been printed and the date when the Imaging Unit was installed. The pages printed may not be an accurate representation of the life left because life is decremented by rotations and pixels printed. Also the install date will change to the current date if Imaging Units are swapped.
209	Image Unit Remaining %	This is an accurate representation of the life remaining on the Imaging Unit as it is a reflection of rotations and pixels imaged
218	Fuser Installation	This token tracks how many letter/A4 equivalent pages have been through the fuser and tells us when the Fuser was installed. However, this tells us nothing about the paper type going through the fuser or how much life is left.
225	Fuser Remaining %	This is an accurate representation of the fuser life remaining because this percentage has taken into account what paper types and sizes have gone through the fuser.
232	Supplies Replaced	This is not an accurate representation of how many times an actual consumable has been replaced. This is just a count of the number of times a particular message has appeared in the front panel. Although an accurate minimum representation is the number of Toner Empty or Waste Cartridge Full messages because the customer is forced to replace the consumable at the empty point. But if a customer is replacing a consumable sometime during the multiple times that the Toner-Low or Waste Cartridge-Almost Full message is appearing before it goes to empty, there is no way to correlate the number of consumables used to the number of times the Low message has appeared.
243	Toner Installation date	This will tell you when a new toner cartridge was installed and how many pages have been printed since installation. But, if used toner cartridges are swapped between printers, this token is no longer accurate.
611	Number of Toner Cartridges Installed	This is an accurate indication of the actual number because the 7750 can detect a new Xerox toner cartridge. Used or non-Xerox cartridges cannot be detected as new though.
612	Number of Imaging Units Replaced	This is based on CRUM data and is accurate unless Imaging Units area swapped.
615	Number of Waste Cartridges Installed	This number assumes the waste cartridge is replaced at the end of life message. If the waste cartridge is replaced when the near end of life message appears, this will not be accurate.
616	Number of Fusers Installed	Whenever the printer sees a fuser installed with all 3 fuses intact this number is incremented.