- High-Speed Printing
While the printing width of existing Bubble Jet printers remains between
9 mm and 13 mm, this advanced print head, a world's first for Canon,
includes a large printing width of 4 inches (about 10 cm) and features a
head carrying a great number of nozzles. It offers two classes of nozzle
density (ink jet density): 360 dpi and 600 dpi. The 360 dpi head comprises
1,360 nozzles laid at an interval of 70.5 micrometers, and the 600 dpi head
has 2,400 nozzles laid at an interval of 42.5 micrometers.
Printing large document on a serial printer, which performs printing
operation by the reciprocating motion of a small print head crosswise, is a
time-taking process. Provided with a printing width long enough to print the
equivalent of the short side of a postcard, the Canon long-line Bubble Jet
print head stays fixed while paper is moved. One postcard can be printed in
full color at an amazingly high speed of just one second. Using higher
numbers of this new print head, it will be possible to print even 60 or more
A4 pages per minute in full color.
- Ultraprecise Array of Nozzles and Heaters
by Exclusive Multichip Head System
The long-line Bubble Jet print head requires the printer nozzles to be
arranged very accurately along a long width of 100 mm, together with their
respective heaters. The number of nozzles/heaters required for this length
amounts to 1,360 (360 dpi). Canon first created a unit with 128
nozzles/heaters, and then invented its original multichip head system. Using
this system, we could array eleven 128-nozzle units very accurately at an
interval of 8 micrometers and a pitch of ñ2 micrometers.
The ink-feed path also posed problems. The aforementioned large number of
nozzles are built in the ink-feed path. The use of plastic could cause the
nozzles/heaters to be dislocated due to the potential difference of thermal
expansion that could occur along a lengthy path of 100 mm. A metal bar was
insertion-molded in the plastic to prevent the dislocation of
nozzles/heaters. In addition, the nozzles were wrought using an excimer
laser. (Canon took the lead in introducing excimer lasers in production
lines.) Various other problems were successfully solved, and the long-line
Bubble Jet print head was consummated.
- 600 dpi Long-Line Bubble Jet Print Head:
a More Microscopic Solution
Comprehensive and sophisticated technologies are required to produce the
long-line Bubble Jet print head, including solutions for mechanical,
electric and material factors. For achievement of a higher-resolution print
head, microscopic and micromachine technologies must also be integrated.
Canon has long been dedicated to research these fundamental technologies.
Canon's comprehensive power based on these steady and dedicated activities
are embodies by the long-line Bubble Jet print head.
The 600 dpi class 4 inch print head, which we developed more recently, lays
2,400 nozzles at an interval of 42.5 micrometers. The nozzle aperture's bore
diameter is 18 micrometers, equivalent to 1/5 the diameter of a human hair.
What was most difficult in this development was elaborating these
extraordinarily fine nozzles consistently and without defect at an accuracy
of ñ1 micrometer. With the nozzle material and machining processes in use
then, it was anticipated that their dimensional accuracy and pitch could not
be ensured throughout the length of 4 inches, and that dislocation from the
heaters would result. Also, they were so microscopic that contamination of
even a few micrometers of foreign matter could result in printing failure.
We started with an extensive analysis of materials in the search for the
right material for these nozzles. The result an exclusive state-of-the-art
photosensitive resin we previously developed for micromachines. A
fabrication process similar to that applied to produce semiconductors was
used to elaborate the nozzles. Finally, we achieved a 4 inch-long print head
with an extraordinarily fine 2,400 nozzles without contamination at an
accuracy of ñ1 micrometer.
In parallel, the head structure was made compact, and we achieved a
configuration of 6 heads in a line to create a high-speed photo-quality
color card printer.