The iP4000 photo printer features the Canon Think Tank System™, an intelligent ink-management system that uses individual ink tanks for each color. You replace only the color that runs out rather than an entire, expensive, multi-color cartridge.

This is the sight that greets you when you lift the cover on the iP4000 printer. Canon's new ContrastPLUS 5-color ink system consists of the usual cyan, magenta and yellow inks and adds a dye-based photo-grade black ink tank for photo printing which delivers improved image contrast and sharpness when used on photo paper. And a larger pigment-based black ink tank to produce crisp, fast, high-quality black text.

The iP4000 features a newly designed PIXMA printhead which employs Canon's FINE (Full-photolithography Inkjet Nozzle Engineering) technology. It has a total of 1,856 nozzles for exceptional speed and quality. The long printhead shown in the picture above is used with the pigment black ink for printing high-speed black text. The printhead on the right is used for color printing. This printhead uses Canon’s exclusive advanced MicroFine Droplet Technology™, which ejects consistent prescribed-volume ink droplets (as small as 2pl) for smooth gradations, accurate skin tones and rich, vibrant colors. The width of these printheads is the key to the printer's speed, a wider head means a larger area of coverage per pass is possible.

Not only can the user replace the individual ink tanks, you can also replace the entire print head if necessary. (Replacement print heads are available from Canon Service after it is determined that a replacement is necessary.)   Epson printers require a trip to the service center when they encounter a print head problem.

Optical ink sensors automatically monitor all ink color levels and communicate with your computer--giving you a pop-up message indicating exactly what colors are running low. You can also check the status of the ink tanks at any time using the Status Monitor of the driver as shown above.

Canon's optical low ink detection system prevents wasted printouts by notifying you via the Printer Status Monitor before any ink tank becomes empty, so you'll never unexpectedly run out of ink in the middle of a job again.

A light beam shines through a prism located at the bottom of each ink tank. When there is sufficient ink, the light is detected by the sensor. When only about 20% of ink is left in any of the ink tanks, the light beam is refracted, triggering the sensor which tells the printer driver to display a low ink tank notification for that ink tank.