That's not necessarily toner left in the cartridge. It could be developer. Laser printers have 2 separate forms of powder inside of them. One being toner, and the other being developer.
The developer has fine metal particulates inside that "charge" the toner, enabling the toner to be pulled off of the drum, and onto the page.
Larger copiers have the Developer, and toner separate. However, the cartridge pictured is the full process unit.
The developer has fine metal particulates inside that "charge" the toner, enabling the toner to be pulled off of the drum, and onto the page.
Larger copiers have the Developer, and toner separate. However, the cartridge pictured is the full process unit.