Brother HL-5440D Service Manual page 277

Life of toner cartridge
<Method of detecting toner volume>
Toner volume is monitored by the toner sensor and by the number of rotations of the
developer roller. When the toner sensor detects that the toner has run out or when the
number of rotations of the developer roller reaches the limit, "Replace Toner" is displayed for
LCD models, or the Toner LED and Error LED light for LED models.
• Detection by toner sensor
The machine is equipped with a function to detect the remaining toner by checking the
level at which the toner in the cartridge obstructs light from the transmission light sensor.
• Detection by number of rotations of developer roller
The machine is equipped with a function to detect the limit of the number of rotations of the
developer roller before the roller becomes abraded and unusable.
<Relationship between printable pages of toner cartridge and remaining toner>
Toner life
Full
High-duty
Low
Empty
Memo:
• When the number of rotations of the developer roller reaches the limit, a message
prompting the user to replace the toner cartridge appears even if some toner
remains.
The table below shows the life of toner cartridges, assuming that the print pattern specified by
ISO/IEC 19752 is printed. (Point 2 in the figure above)
Toner cartridge
Starter
Standard
High
Super high
Normal-duty
(ISO/IEC19752)
Toner Empty Toner Empty
Printable pages
2,000
3,000
8,000
12,000
5-52
Low-duty
Cartridge Life End
pages
Confidential