Hello fxfox,
The simple answer is inkjet printers shoot/spray tiny drops of ink
onto the paper, a bubblejet heats the drop before spraying, and a
laser printer, after numerous complicated steps of charging and
discharging a wire, rolling a drum, magnetizing the drum, it finally
heat fuses the toner (sometimes called ink-dust) onto the paper. Whew!
I?ll elaborate further.
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Inkjet:
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Inkjet printers became commonplace in the late 1980s, and work, simply
put, by spraying tiny droplets of ink from nozzles on the paper.
Earlier than the late 80?s, dot matrix printers were used. ?Dot matrix
printers use a series of small pins to strike a ribbon coated with
ink, causing the ink to transfer to the paper at the point of impact.?
http://www.howstuffworks.com/inkjet-printer.htm
A bit more about the old dot-matrix printers:
?An inked ribbon creates the image on the paper. Operation and Architecture:
A dot-matrix printer can use tractor-fed paper or friction rollers to
feed paper into the printer. Tractor feeds either push paper into the
printer or pull paper out of the printer to move paper. In a printer
using friction rollers, the feed mechanism usually pushes the paper
into the printer.
As paper is fed through the printer, it runs across a flat piece of
metal called a platen. A printhead fires an array of pins into an
inked ribbon that strikes the paper as it crosses the platen. The
array of pins is fired at precise times to form characters or pictures
on the paper.
http://www.windowsitlibrary.com/Content/175/11/1.html
?Another style is called a "dot matrix", because little pins would tap
out a lot of little dots in a grid to make letters and shapes. The
only reason they still exist, is because they can still fill out older
style forms with carbon or create brail transcripts; since they
actually strike something to the paper with some force. But now days
these are becoming very rare other than at old bureaucracies.?
http://www.igeek.com/articles/Hardware/Printers.txt
Back to inkjets!: You can see inside a print head assembly here:
http://computer.howstuffworks.com/inkjet-printer2.htm
?Print head stepper motor - A stepper motor moves the print head
assembly (print head and ink cartridges) back and forth across the
paper. Some printers have another stepper motor to park the print head
assembly when the printer is not in use. Parking means that the print
head assembly is restricted from accidentally moving, like a parking
brake on a car.?
http://computer.howstuffworks.com/inkjet-printer2.htm
Most inkjet cartridges have the print head built in. This makes the
price of the printer very cheap, while cartridges are quite costly!
?Another way that they have reduced costs is by incorporating much of
the actual print head into the cartridge itself. The manufacturers
believe that since the print head is the part of the printer that is
most likely to wear out, replacing it every time you replace the
cartridge increases the life of the printer.? You can see a photo
here:
http://computer.howstuffworks.com/inkjet-printer5.htm
On the page above, you will see an example of why you should use
inkjet paper (made especially for inkjet printers). The ink will
feather out, causing blurred printing if you use cheap or non-inkjet
paper.
?For most inkjet printers, the print head takes about half a second to
print the strip across a page. On a typical 8 1/2"-wide page, the
print head operating at 300 dpi deposits at least 2,475 dots across
the page. This translates into an average response time of about
1/5000th of a second. Quite a technological feat! In the future,
however, advances will allow for larger print heads with more nozzles
firing at faster frequencies, delivering native resolutions of up to
1200dpi and print speeds approaching those of current color laser
printers (3 to 4 pages per minute in color, 12 to 14ppm in
monochrome). In other words, declining costs for improving
technology.?
http://www.inkjetcartridges.com/_Info-How-Inkjet-Printers-Work.html
?Inkjets work by spitting, yes, I said spitting tiny dots of colored
ink onto a page. Most of this printing action takes place in the
nozzles of the print cartridge. What happens is a interface circuit in
the cartridge applies a charge. This is applied to a series of what is
called impulse drivers that correspond to the selected colors. Now
there are two ways to get the ink out of that cartridge. This is done
with by charging and heating up a small amount of ink till it is a
vapor ball and gets pushed onto the page. The other method is to apply
a charge to a piezoelectric driver(Big Word) that is made up of
synthetic quartz. The quartz expands and then pushes the ink onto the
paper. This is similar to fuel injector in a sense.?
http://www.waterwheel.com/Guides/printers/printers.htm
You can see an illustration of a droplet being sprayed out here.
http://www.inkjetcartridges.com/_thermo-technology.html
?Inkjet printing has two chief benefits over laser printers: lower
printer cost and color-printing capabilities. But while inkjet
printers are priced much less than laser printers, they are actually
more expensive to use and maintain. Cartridges need to be changed more
frequently and the special coated paper required to produce
high-quality output is very expensive. At a cost per page level,
inkjet printing costs about 10 times more than laser printing.?
http://www.inkjetcartridges.com/_Info-How-Inkjet-Printers-Work.html
?Because the paper does not pass through an area where a print head
strikes the paper, paper jams do not occur as often in inkjet printers
as they can in dot matrix printers. The paper feed mechanism pushes
the paper into the device via paper pickup rollers, which pull the top
sheet of paper from a stack and feed it into the print mechanism.
Troubleshooting
---------------
Inkjet printers rely on a minute nozzle to spray ink in a controlled
burst onto the printer. Some of the typical inkjet printer problems
include:
·Light or poor print quality ? Can be caused by the a low level of ink
in the ink reservoir. You should replace the ink cartridge and run
several test pages. If the test appears to smear, the printer may be
dispensing too much ink, or the quality of paper may be inferior.
·Paper feeds multiple sheets at a time ? Typically caused by dirty
paper pickup rollers. Clean or replace the rollers as specified by the
manufacturer.
Almost all print-quality problems in inkjet printers are caused by a
defective print head. Fortunately, most inkjet printers have a
combination head/ink reservoir, so replacing the ink cartridge and
running several test prints through the printer usually clears the
problem.?
http://www.windowsitlibrary.com/Content/175/11/1.html
Additionally, a similar technique is known as ?Piezoelectric? and was
invented by Epson. ?This technology uses piezo crystals. A crystal is
located at the back of the ink reservoir of each nozzle. The crystal
receives a tiny electric charge that causes it to vibrate. When the
crystal vibrates inward, it forces a tiny amount of ink out of the
nozzle. When it vibrates out, it pulls some more ink into the
reservoir to replace the ink sprayed out.
http://computer.howstuffworks.com/inkjet-printer3.htm
?Because the Piezo process can deliver small and perfectly formed dots
with extreme accuracy, Epson is able to offer an enhanced resolution
of 1440 by 720dpi (although this is achieved by the print-head making
two passes, with a consequent reduction in print speed). The inks that
Epson has developed for use with its Piezo technology are
solvent-based and extremely quick drying. They penetrate the paper and
maintain their shape rather than spreading out on the surface and
causing dots to interact with one another. The result is extremely
fine print quality, especially on coated or glossy paper.?
http://www.inkjetcartridges.com/_piezo-electric-technology.html
A little known use of inkjet printers is for tissue engineering.
Scientists are actually laying down cell layers (printing!) thin
sheets of tissue! Since I read this about a year ago, it is the first
thing I think of whenever I hear about inkjet printers. (I spent 25
years in the health care field!)
http://www.futurepundit.com/archives/000899.html
http://www.eurekalert.org/pub_releases/2001-03/PNNL-Pghp-2803101.php
http://www.newscientist.com/news/news.jsp?id=ns99993292
=========
BubbleJet
=========
BubbleJet is a proprietary brand name of printers manufactured by
Canon. HP also uses the same method, ?Thermal Bubble? in some models.
Canon says that they invented this technology in 1977 when a
technician heated, by accident, an ink-filled syringe, with a
soldering iron. The heated ink was forced out of the needle and gave
rise to the idea of heating the ink.
http://www.pctechguide.com/13inkjets.htm
?In a thermal inkjet printer, tiny resistors create heat, and this
heat vaporizes ink to create a bubble. As the bubble expands, some of
the ink is pushed out of a nozzle onto the paper. When the bubble
"pops" (collapses), a vacuum is created. This pulls more ink into the
print head from the cartridge. A typical bubble jet print head has 300
or 600 tiny nozzles, and all of them can fire a droplet
simultaneously.?
http://computer.howstuffworks.com/inkjet-printer3.htm
Canon?s site states: ?Ink is heated by running an instantaneous
electric current through the micro-heater, so that ink droplets jet
out of the nozzle under the pressure of the heat. This technology has
enabled us to offer much more affordable and high-quality printers
than standard ink-jet printers using piezoelectric devices. The Canon
Bubble Jet system is an unprecedented ink-jet printing method, born
from the uncompromising desire of our engineers to create an ideal
printer that makes everyone's dreams of imaging come true.?
http://www.canon.co.uk/about_us/about_canon/canon_technology/bubble_jet_technology.asp
?Most inkjets use thermal technology, whereby heat is used to fire ink
onto the paper. There are three main stages in this process. The
squirt is initiated by heating the ink to create a bubble until the
pressure forces it to burst and hit the paper. The bubble then
collapses as the element cools, and the resulting vacuum draws ink
from the reservoir to replace the ink that was ejected. Canon and
Hewlett-Packard favor this method?
http://www.inkjetcartridges.com/_thermo-technology.html
For detailed steps on how a printer works, from clicking the ?Print?
button, to the finished product, read this page:
http://computer.howstuffworks.com/inkjet-printer4.htm
====================================
LaserJet printers vs. Laser printers
====================================
It?s all about the uniformly shaped particles! LaserJet is HP?s
proprietary name and technology for laser printing. ?Did you know that
70% of the printer imaging system is contained in the HP LaserJet
print cartridges? Because print cartridges are the central piece of HP
LaserJet technology, HP takes them very seriously. Every HP LaserJet
cartridge is specially designed and custom engineered to work
flawlessly with its HP LaserJet printer to provide clear, sharp output
over the life of the cartridge.
HP LaserJet ultraprecise print cartridges set the standard for print
quality and reliability by delivering breakthrough newtechnologies for
more consistent output, smooth grayscales, fine details and optimum
quality graphics throughout the life of the cartridge. And best of all
no more cartridge leaks thanks to a new magnetic seal!
Receive optimum printing results from your HP LaserJet 2200 Series
printer? use HP LaserJet ultraprecise print cartridges to deliver
output that is always clear, always sharp.?
http://www.laser-life.com/HP/LaserJet_2200.html
HP claims their Laserjet toner is more precise than conventional
toners. ?There's a lot more to HP toner than meets the eye. Unlike
conventional mechanically ground toners, the polymerized toner used in
the latest HP Color LaserJet printers is formed through precisely
controlled chemical reactions. Each spherical particle is grown in
layers designed to interact with the printing system. These particles
transfer to paper with the highest precision for consistently accurate
images.
Chemical toner is designed for the exacting process of color printing.
Conventional toner has irregularly shaped particles, whereas chemical
toner has smooth, spherically shaped particles. The uniform spherical
toner particles allow consistent charging and flow of toner for
accurate color images. A soft wax core in each particle melts as the
toner is fused to the paper, ensuring fast, even fusing. Improved,
patented pigments are another key ingredient in HP toner. They have
been modified to achieve the most lifelike images, improved print
quality in overhead transparencies, and broader color range in photo
images.?
http://www.hp.com/sbso/product/supplies/color_laserjet_express.html
?HP Color LaserJet printing supplies are key components of the in-line
architecture that brings reliable performance and highly accurate
color registration to selected new HP Color LaserJet printers. Four
individual cartridges are aligned in fixed positions to apply toner
directly to paper in one pass through the printer. New all-in-one
cartridges combine numerous components into one user-replaceable
cartridge for each color. And all essential process-related components
subject to wear are replaced each time a new cartridge is installed.
It all adds up to fast, reliable quality.?
http://www.hp.com/sbso/product/supplies/color_laserjet_explore.html
?The toner cartridge is the engine that makes all HP laser printers
hum, so we never stop in our pursuit of the perfect cartridge. It all
starts with the toner itself. Did you know that the HP toner particles
are so fine that 5 trillion particles fit into a single toner
cartridge? HP toner is chemically grown, which allows us to precisely
control the size and shape of the toner particles. Small, uniform
particle size translates to better color trueness and uniform
pigmentation, while the spherical shape of the particles means that
you?ll get more consistent color printing. This toner is then packed
into a toner cartridge that can do a lot of smart things, like tell
you when it?s time to reorder or replace.?
http://h30015.www3.hp.com/hp_printing_system/home_printing/toner_cartridges.asp
Laser printers are quite a bit more complex. However, while the
initial cost of a laser toner cartridge is costly, it is a real
bargain in the long run. They are also faster and quieter! (I have a
small home laser printer ($150), and I get thousands of prints from on
$60 toner cartridge. In fact, I have had the same cartridge for over a
year, and I print at least 2 prints a day, often 15-30 a day).
?Laser printers tend to be more expensive than inkjet printers, but it
doesn't cost as much to keep them running -- toner powder is cheap and
lasts a long time, while you can use up expensive ink cartridges very
quickly. This is why offices typically use a laser printer as their
"work horse," their machine for printing long text documents. In most
models, this mechanical efficiency is complemented by advanced
processing efficiency. A typical laser-printer controller can serve
everybody in a small office.?
http://computer.howstuffworks.com/laser-printer12.htm
?One of the distinguishing features of laser printers is their
resolution. The ready resolutions extent from 300 dpi (dots per inch)
at the bottom end to 1,200 dpi at the top end. If you compare, offset
printing normally prints at 1,200 or 2,400 dpi. Some laser printers
achieve higher resolutions with distinguish techniques generally known
as resolution enhancement.?
http://www.cartridgesave.co.uk/laser-toner-uk.html
?A type of printer that utilizes a laser beam to produce an image on a
drum. The light of the laser alters the electrical charge on the drum
wherever it hits. The drum is then rolled through a reservoir of
toner, which is picked up by the charged portions of the drum.
Finally, the toner is transferred to the paper through a combination
of heat and pressure. This is also the way copy machines work.?
http://www.webopedia.com/TERM/L/laser_printer.html
?Initially, the drum is given a total positive charge by the charge
corona wire, a wire with an electrical current running through it.
(Some printers use a charged roller instead of a corona wire, but the
principle is the same.) As the drum revolves, the printer shines a
tiny laser beam across the surface to discharge certain points. In
this way, the laser "draws" the letters and images to be printed as a
pattern of electrical charges -- an electrostatic image. The system
can also work with the charges reversed -- that is, a positive
electrostatic image on a negative background.?
?With the powder pattern affixed, the drum rolls over a sheet of
paper, which is moving along a belt below. Before the paper rolls
under the drum, it is given a negative charge by the transfer corona
wire (charged roller). This charge is stronger than the negative
charge of the electrostatic image, so the paper can pull the toner
powder away. Since it is moving at the same speed as the drum, the
paper picks up the image pattern exactly.?
The paper then passes through heated rollers that fuse the toner onto the paper.
http://computer.howstuffworks.com/laser-printer2.htm
See an illustration of inside a laser printer.
http://computer.howstuffworks.com/laser-printer1.htm
The assembly
http://computer.howstuffworks.com/laser-printer7.htm
Laser toner is not ink at all, but a mixture of plastic and pigment.
This mixture is heated and bonded onto the paper, producing a crisp
image that won?t smudge or bleed.
http://computer.howstuffworks.com/laser-printer9.htm
?A laser print engine is made up of several components. Only two or
three print engines are used in all the major brands of laser printers
available today, and most work in a similar manner. The major
components in a laser printer and the role of each is explained below.
·Cleaning stage ? A photosensitive drum known as an Environmental
Photocell (EP) cartridge is exposed to an erasure lamp to evenly
charge the drum and prepare it to accept data.
·Writing stage ? The data received from the PC fires a laser into a
mirror, which reflects the beam to a photosensitive drum. The the
image that will be transferred to the paper is drawn on the
photosensitive drum.
·Developing stage ? Toner is attracted to the areas of the
photosensitive drum that have been struck by the laser.
·Transferring stage ? Paper running through the print mechanism is
charged to a greater potential than the photosensitive drum by a
transfer corona wire. As the paper passes near the photosensitive
drum, the toner is transferred to the paper.
·Fusing stage ? The paper is fed into a fuser assembly that is heated
to more than 600 degrees, which melts or ?fuses? the toner to the
paper.
·Final stage ? Export rollers receive the paper from the fuser
assembly and push the paper out of the printer.
The drum is made of a fragile material that can be damaged by light or
dirt, so you should never touch the photosensitive drum or expose it
to light for extended periods of time.?
Troubleshooting:
·Poor print quality ? The most common cause of poor print quality is
the toner cartridge. If possible, replace the toner cartridge and
print several test pages. Rebuilt toner cartridges can be newly
installed and still print poor-quality pages. Look at the fuser and
make sure the roller is free of dirt and is not marred. Look at the
mirror in the lid and make sure it is free of oil, dirt, and debris.
·Paper jams ? First, you need to determine whether the paper is
jamming at the entrance or while exiting. The fuser assembly can be
considered the midway point. Make sure the pickup rollers are free of
dirt or oil and are not worn or cracked. Make sure the paper path is
free of paper and debris. If the paper is jamming during exit, make
sure the gears on the fuser assembly aren?t damaged.
http://www.windowsitlibrary.com/Content/175/11/1.html
Laser Speed
------------
Laser printer speed, PPM (pages per minute) is one of the most
important factors when purchasing a laser printer. Laser Printers are
divided into different segments, depending upon usage.
1 - 4 PPM
Laser printers in this category are low end printers that are normally
personal laser printers. The most common uses include: simple word
processing, infrequent use of special fonts and simple documents.
Prices for these speed range from $300 to $600
6 - 10 PPM
This class of printers are office printers. These are the most common
printers people see today. Prices range from $500 to $1500 for these
printers.
12 - 20 PPM
Printers in the 12 - 20 PPM range are high end network printers. Price
vary from $1500 - $3000. These printer exist in a department or
network environment.
http://www.morelaser.com/info/printerwork.htm
Inside an HP LaserJet printer
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=bpl07726
Color Lasers
------------
?Essentially, color printers work the same way as monochrome printers,
except they go through the entire printing process four times -- one
pass each for cyan (blue), magenta (red), yellow and black. By
combining these four colors of toner in varying proportions, you can
generate the full spectrum of color.?
http://computer.howstuffworks.com/laser-printer11.htm
Dye Sublimation Printers - an expensive alternative color printer.
?In dye-sublimation printing, colors are not laid down as individual
dots, as is done in inkjet printers. Individual dots can be
distinguished at a relatively close distance, making digital pictures
look less realistic.
If you looked inside a dye-sublimation printer, you would see a long
roll of transparent film that resembles sheets of red, blue, yellow,
and gray colored cellophane stuck together end to end. Embedded in
this film are solid dyes corresponding to the four basic colors used
in printing: cyan, magenta, yellow and black. The print head heats up
as it passes over the film, causing the dyes to vaporize and permeate
the glossy surface of the paper before they return to solid form.
So the main difference between this and other types of printing has to
do with heat. The vaporized colors permeate the surface of the paper,
creating a gentle gradation at the edges of each pixel, instead of the
conspicuous border between dye and paper produced by inkjets. And
because the color infuses the paper, it is also less vulnerable to
fading and distortion over time.?
http://www.howstuffworks.com/question583.htm
?A dye sublimation printer creates color on the printed page by
vaporizing inks, which then solidify (or "sublimate") on the page. The
ink combines into a smoothly mixed color dot, allowing the printer to
accurately reproduce the color of the original image. By comparison,
other printer technologies use small dots of fixed colors to fool the
eye into seeing smooth color ("dithering").?
http://peripherals.about.com/library/glossary/bldefdyesublimationprinter.htm
http://businessweek.com.com/Olympus_P_440/4505-3167_7-30565142.html?subj=Olympus+P-440&tag=feed&part=businessweek
To summarize, inkjet and BubbleJet printers are cheaper to buy than
lasers, but cost more to maintain.Lasers are faster and quieter, and
produce crisp, clear text. Color laser is highly expensive, and out of
reach for most home users at this time. If you want to print in color,
but are printing a large amount in black ink, having a home laser AND
a color inkjet may be cheaper for you.
Hope this helps. If any part of my answer is unclear, please request
an Answer Clarification, before rating. This will allow me to assist
you further, if possible.
Regards,
crabcakes
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