Inkjet printer - AbsoluteAstronomy.com

An inkjet printer is a type of computer printer that creates a digital image

Digital image

A digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...

by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines that can cost up to thousands of dollars.

The concept of inkjet printing originated in the 19th century, and the technology was first extensively developed in the early 1950s. Starting in the late 1970s inkjet printers that could reproduce digital images generated by computers were developed, mainly by Epson, Hewlett-Packard

Hewlett-Packard

Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...

(HP), and Canon

Canon Inc.

is a Japanese multinational corporation that specialises in the manufacture of imaging and optical products, including cameras, camcorders, photocopiers, steppers and computer printers. Its headquarters are located in Ōta, Tokyo, Japan.-Origins:...

. In the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales: Canon, HP, Epson, and Lexmark

Lexmark

Lexmark International, Inc. is an American corporation which develops and manufactures printing and imaging products, including laser and inkjet printers, multifunction products, printing supplies, and services for business and individual consumers...

, a 1991 spin-off from IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

.

The emerging ink jet material deposition

Ink jet material deposition

Ink jet material deposition is an emerging manufacturing technique in which ink jet technology is used to deposit materials on substrates. The technique aims to eliminate fixed costs of production and reduce the amount of materials used.-Uses:...

market also uses inkjet technologies, typically printheads using piezoelectric crystals, to deposit materials directly on substrates.

Technologies

There are two main technologies in use in contemporary inkjet printers: continuous (CIJ) and Drop-on-Demand (DOD). Drop-on-demand is further divided into thermal DOD and piezoelectric DOD

Continuous inkjet (CIJ)

The continuous inkjet method is used commercially for marking and coding of products and packages. The idea was first patented in 1867 by Lord Kelvin

William Thomson, 1st Baron Kelvin

William Thomson, 1st Baron Kelvin OM, GCVO, PC, PRS, PRSE, was a mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging...

, and the first commercial devices (medical strip chart recorder

Chart recorder

A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper . Chart recorders may record several inputs using different color pens and may record onto strip charts or circular charts...

s) were introduced in 1951 by Siemens

Siemens

Siemens may refer toSiemens, a German family name carried by generations of telecommunications industrialists, including:* Werner von Siemens , inventor, founder of Siemens AG...

.

In continuous inkjet technology, a high-pressure pump directs liquid ink from a reservoir through a gunbody and a microscopic nozzle, creating a continuous stream of ink droplets via the Plateau-Rayleigh instability

Plateau-Rayleigh instability

The Plateau–Rayleigh instability, often just called the Rayleigh instability, explains why and how a falling stream of fluid breaks up into smaller packets with the same volume but less surface area. It is related to the Rayleigh–Taylor instability...

. A piezoelectric crystal creates an acoustic wave as it vibrates within the gunbody and causes the stream of liquid to break into droplets at regular intervals – 64,000 to 165,000 droplets per second may be achieved. The ink droplets are subjected to an electrostatic field created by a charging electrode as they form; the field varies according to the degree of drop deflection desired. This results in a controlled, variable electrostatic charge on each droplet. Charged droplets are separated by one or more uncharged “guard droplets” to minimize electrostatic repulsion between neighbouring droplets.

The charged droplets pass through an electrostatic field and are directed (deflected) by electrostatic deflection plates to print on the receptor material (substrate), or allowed to continue on undeflected to a collection gutter for re-use. The more highly charged droplets are deflected to a greater degree. Only a small fraction of the droplets is used to print, the majority being recycled.

Continuous ink jet is one of the oldest ink jet technologies in use and is fairly mature. The major advantages are the very high velocity (~50 m/s) of the ink droplets, which allows for a relatively long distance between print head and substrate, and the very high drop ejection frequency, allowing for very high speed printing. Another advantage is freedom from nozzle clogging as the jet is always in use, therefore allowing volatile

Volatility (chemistry)

In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...

solvents such as ketones and alcohols to be employed, giving the ink the ability to "bite" into the substrate and dry quickly.

The ink system requires active solvent regulation to counter solvent evaporation during the time of flight (time between nozzle ejection and gutter recycling), and from the venting process whereby air that is drawn into the gutter along with the unused drops is vented from the reservoir. Viscosity is monitored and a solvent (or solvent blend) is added to counteract solvent loss.

Thermal (thermal DOD inkjet)

Most consumer inkjet printers, from companies including Canon, Hewlett-Packard

Hewlett-Packard

, and Lexmark

Lexmark

(but not Epson), use print cartridges with a series of tiny chambers each containing a heater, all of which are constructed by photolithography

Photolithography

Photolithography is a process used in microfabrication to selectively remove parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate...

. To eject a droplet from each chamber, a pulse of current is passed through the heating element causing a rapid vaporisation of the ink in the chamber to form a bubble, which causes a large pressure increase, propelling a droplet of ink onto the paper (hence Canon's tradename of Bubble Jet). The ink's surface tension

Surface tension

Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...

, as well as the condensation and thus contraction of the vapor bubble, pulls a further charge of ink into the chamber through a narrow channel attached to an ink reservoir.

The inks used are usually water-based (aqueous) and use either pigment

Pigment

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

s or dye

Dye

A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....

s as the colorant. The inks used must have a volatile component to form the vapor bubble, otherwise droplet ejection cannot occur. As no special materials are required, the print head is generally cheaper to produce than in other inkjet technologies. The thermal inkjet principle was discovered by Canon engineer Ichiro Endo in August 1977.

Thermal inkjet printers are not the same as thermal printer

Thermal printer

A thermal printer produces a printed image by selectively heating coated thermochromic paper, or thermal paper as it is commonly known, when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image...

s, which produce images by heating thermal paper, as seen on older fax machines, cash registers, ATM receipt printers, and lottery ticket printers.

Piezoelectric (piezoelectric DOD inkjet)

Most commercial and industrial inkjet printers and some consumer printers (those produced by Epson and Brother Industries

Brother Industries

is a diversified Japanese company that produces or imports a wide variety of products including printers, sewing machines, large machine tools, label printers, and typewriters, fax machines, and other computer-related electronics. It markets its multifunction printers as Multi-Function Centers...

) use a piezoelectric material

Piezoelectricity

Piezoelectricity is the charge which accumulates in certain solid materials in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure...

in an ink-filled chamber behind each nozzle instead of a heating element. When a voltage is applied, the piezoelectric material changes shape, which generates a pressure pulse in the fluid forcing a droplet of ink from the nozzle. Piezoelectric (also called Piezo) inkjet allows a wider variety of inks than thermal inkjet as there is no requirement for a volatile component, and no issue with kogation (buildup of ink residue), but the print heads are more expensive to manufacture due to the use of piezoelectric material (usually PZT, lead zirconium titanate). A drop-on-demand process uses software that directs the heads to apply between zero to eight droplets of ink per dot, only where needed.

Piezo inkjet technology is often used on production lines to mark products - for instance the "use-before" date is often applied to products with this technique; in this application the head is stationary and the product moves past. Requirements of this application are high speed, a long service life, a relatively large gap between the print head and the substrate, and low operating cost.

As of June 2009, the fastest cut-sheet inkjet printer on the market is the RISO ComColor 9050, which prints 146 USLetter and 150 A4 full-color pages per minute in both one-sided and two-sided printing modes.

Recent developments of piezo inkjet technology are extending the technique from printing into manufacturing processes. The newest of these technologies is to deposit layers of plastic material as digital embossing over the top of printed works.

Ink formulations

The basic problem with inkjet inks is the conflicting requirements for a coloring agent that will stay on the surface vs. rapid dispersement of the carrier fluid.

Desktop inkjet printers, as used in offices or at home, tend to use aqueous inks based on a mixture of water, glycol and dye

Dye

s or pigments. These inks are inexpensive to manufacture, but are difficult to control on the surface of media, often requiring specially coated media. HP inks contain sulfonated polyazo black dye (commonly used for dying leather

Leather

Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...

), nitrates and other compounds. Aqueous inks are mainly used in printers with thermal inkjet heads, as these heads require water to perform.

While aqueous inks often provide the broadest color gamut and most vivid color, most are not waterproof without specialized coating or lamination after printing. Most Dye

Dye

-based inks, while usually the least expensive, are subject to rapid fading when exposed to light. Pigment

Pigment

-based aqueous inks are typically more costly but provide much better long-term durability and ultraviolet

Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

resistance. Inks marketed as “Archival Quality” are usually pigment-based.

Some professional wide format printers use aqueous inks, but the majority in professional use today employ a much wider range of inks, most of which require piezo inkjet heads and extensive maintenance:

Solvent inks: the main ingredient of these inks are volatile organic compounds (VOCs)
Volatile organic compound
Volatile organic compounds are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and...

, organic chemical compounds that have high vapor pressure
Vapor pressure
Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system. All liquids have a tendency to evaporate, and some solids can sublimate into a gaseous form...

s. Color is achieved with pigments rather than dyes for excellent fade-resistance. The chief advantage of solvent inks is that they are comparatively inexpensive and enable printing on flexible, uncoated vinyl
Vinyl
A vinyl compound is any organic compound that contains a vinyl group ,which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group...

substrates, which are used to produce vehicle graphics, billboards, banners and adhesive decals. Disadvantages include the vapour produced by the solvent and the need to dispose of used solvent. Unlike most aqueous inks, prints made using solvent-based inks are generally waterproof and ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

-resistant (for outdoor use) without special over-coatings. The high print speed of many solvent printers demands special drying equipment, usually a combination of heaters and blowers. The substrate is usually heated immediately before and after the print heads apply ink. Solvent inks are divided into two sub-categories:
- Hard solvent ink offers the greatest durability without specialized over-coatings but requires specialized ventilation of the printing area to avoid exposure to hazardous fumes.
- Mild or "Eco" solvent inks, while still not as safe as aqueous inks, are intended for use in enclosed spaces without specialized ventilation of the printing area. Mild solvent inks have rapidly gained popularity in recent years as their color quality and durability have increased while ink cost has dropped significantly.
UV-curable inks: these inks consist mainly of acrylic monomer
Monomer
A monomer is an atom or a small molecule that may bind chemically to other monomers to form a polymer; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex...

s with an initiator package. After printing, the ink is cured by exposure to strong UV-light. The advantage of UV-curable inks is that they "dry" as soon as they are cured, they can be applied to a wide range of uncoated substrates, and they produce a very robust image. Disadvantages are that they are expensive, require expensive curing modules in the printer, and the cured ink has a significant volume and so gives a slight relief on the surface. Though improvements are being made in the technology, UV-curable inks, because of their volume, are somewhat susceptible to cracking if applied to a flexible substrate. As such, they are often used in large "flatbed" printers, which print directly to rigid substrates such as plastic, wood or aluminum where flexibility is not a concern.

UV Curable Ink Properties and Functions:

• Photoinitiators: Absorb the UV energy from the light source on the print head. Chemical reaction occurs that converts the liquid ink into a solid film.

• Monomers: Used as solvents because of their ability to reduce viscosity (thickness) and combine with other ink components. 100% percent solids and do not release VOCs (volatile organic compounds). Monomers also add improved film hardness and resistance properties.

• Oligomers: Determine the final properties of the cured ink film, including its elasticity, outdoor performance characteristics and chemical resistance.

• Colorants: Can be dye-based or pigment-based. Usually, pigment-based because of the greater light fastness and durability of pigments compared with dyes. Pigments used in outdoor advertising and display applications have similar requirements to those used in automotive paints. Consequently, there is some crossover of use. While a pigment is selected on the basis of the required application, size control and reduction along with dispersion technique are major components of ink formulation.

UV Ink Printing Process:

Ink is exposed to UV radiation where a chemical reaction takes place where the photo-initiators cause the ink components to cross-link into a solid.
Typically a shuttered mercury-vapor lamp is on either side of the print head, and produces a great amount of heat to complete the curing process (this lamp is used for free radical UV ink, which is what the majority of flatbed inkjet systems use).
UV inks do not evaporate, but rather cure or set as a result from this chemical reaction.
No material is evaporated or removed, which means about 100% of the delivered volume is used to provide coloration.
This reaction happens very quickly, which leads to instant drying that results in a completely cured graphic in a matter of seconds. This also allows for a very fast print process.
As a result of this instant chemical reaction no solvents penetrate the substrate once it comes off the printer, which allows for high quality prints.

Dye sublimation inks: these inks contain special sublimation dyes and are used to print directly or indirectly on to fabrics which consist of a high percentage of polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...

fibres. A heating step causes the dyes to sublimate into the fibers and create an image with strong color and good durability.

Head design

There are two main design philosophies in inkjet head design: fixed-head and disposable head. Each has its own strengths and weaknesses.

Fixed head

The fixed-head philosophy provides an inbuilt print head (often referred to as a gaiter- head) that is designed to last for the life of the printer. The idea is that because the head need not be replaced every time the ink runs out, consumable costs can be made lower and the head itself can be more precise than a cheap disposable one, typically requiring no calibration. On the other hand, if a fixed head is damaged, obtaining a replacement head can become expensive, if removing and replacing the head is even possible. If the printer's head cannot be removed, the printer itself will then need to be replaced.

Fixed head designs are available in consumer products, but are more likely to be found on industrial high-end printers and large format plotters. In the consumer space, fixed-head printers are manufactured primarily by Epson and Canon. Hewlett-Packard also offers a few fixed-head models, such as the HP Photosmart 3310. Industrial fixed-head print heads are manufactured by these companies: Kodak Versamark, Trident, Xaar, Spectra (Dimatix), Hitachi / Ricoh, HP Scitex, Brother, Konica Minolta, Seiko Epson, and ToshibaTec (a licensee of Xaar).

Disposable head

The disposable head philosophy uses a print head which is supplied as a part of a replaceable ink cartridge

Ink cartridge

An ink cartridge or inkjet cartridge is a replaceable component of an inkjet printer that contains the ink that is deposited onto paper during printing....

. Every time a cartridge is exhausted, the entire cartridge and print head are replaced with a new one. This adds to the cost of consumables and makes it more difficult to manufacture a high-precision head at a reasonable cost, but also means that a damaged or clogged print head is only a minor problem: the user can simply buy a new cartridge. Hewlett-Packard

Hewlett-Packard

has traditionally favoured the disposable print head, as did Canon in its early models. This type of construction can also be seen as an effort by printer manufacturers to stem third party ink cartridge assembly replacements, as these would-be suppliers don't have the ability to manufacture specialized print heads.

An intermediate method does exist: a disposable ink tank connected to a disposable head, which is replaced infrequently (perhaps every tenth ink tank or so). Most high-volume Hewlett-Packard inkjet printers use this setup, with the disposable print heads used on lower volume models. A similar approach is used by Kodak, where the printhead intended for permanent use is nevertheless inexpensive and can be replaced by the user. Canon now uses (in most models) replaceable print heads which are designed to last the life of the printer, but can be replaced by the user if they should become clogged. For Canon models with "Think Tank" technology, the ink tanks are separate for each ink color.

Cleaning mechanisms

The primary cause of inkjet printing problems is due to ink drying on the printhead's nozzles, causing the pigments and dyes to dry out and form a solid block of hardened mass that plugs the microscopic ink passageways. Most printers attempt to prevent this drying from occurring by covering the printhead nozzles with a rubber cap when the printer is not in use. Abrupt power losses, or unplugging the printer before it has capped the printhead, can cause the printhead to be left in an uncapped state. Even when the head is capped, this seal is not perfect, and over a period of several weeks the moisture (or other solvent) can still seep out, causing the ink to dry and harden. Once ink begins to collect and harden, the drop volume can be affected, drop trajectory can change, or the nozzle can completely fail to jet ink.

To combat this drying, nearly all inkjet printers include a mechanism to reapply moisture to the printhead. Typically there is no separate supply of pure ink-free solvent available to do this job, and so instead the ink itself is used to remoisten the printhead. The printer attempts to fire all nozzles at once, and as the ink sprays out, some of it wicks across the printhead to the dry channels and partially softens the hardened ink. After spraying, a rubber wiper blade is swept across the printhead to spread the moisture evenly across the printhead, and the jets are again all fired to dislodge any ink clumps blocking the channels.

Some printers use a supplemental air-suction pump, utilizing the rubber capping station to suck ink through a severely clogged cartridge. The suction pump mechanism is frequently driven by the page feed stepper motor

Stepper motor

A stepper motor is a brushless, electric motor that can divide a full rotation into a large number of steps. The motor's position can be controlled precisely without any feedback mechanism , as long as the motor is carefully sized to the application...

– it is connected to the end of the shaft. The pump only engages when the shaft turns backwards, hence the rollers reversing while head cleaning. Due to the built-in head design, the suction pump is also needed to prime the ink channels inside a new printer, and to reprime the channels between ink tank changes.

Professional solvent- and UV-curable ink wide-format inkjet printers generally include a "manual clean" mode that allows the operator to manually clean the print heads and capping mechanism and to replace the wiper blades and other parts used in the automated cleaning processes. The volume of ink used in these printers often leads to "overspray" and therefore buildup of dried ink in many places that automated processes are not capable of cleaning.

The ink consumed in the cleaning process needs to be collected to prevent ink from leaking in the printer. The collection area is called the spittoon

Inkjet spittoon

An inkjet spittoon is a component in modern-day electronic inkjet printers. Inkjet printers commonly experience a problem of drying out which blocks the flow of ink...

, and in Hewlett Packard printers this is an open plastic tray underneath the cleaning/wiping station. In Epson printers, there is typically a large absorption pad in a pan underneath the paper feed platen. For printers several years old, it is common for the dried ink in the spittoon to form a pile that can stack up and touch the printheads, jamming the printer. Some larger professional printers using solvent inks may employ a replaceable plastic receptacle to contain waste ink and solvent which must be emptied or replaced when full.
There is a second type of ink drying that most printers are unable to prevent. For ink to spray from the cartridge, air must enter to displace the removed ink. The air enters via an extremely long, thin labyrinth tube, up to 10 cm long, wrapping back and forth across the ink tank. The channel is long and narrow to reduce moisture evaporation through the vent tube, but some evaporation still occurs and eventually the ink cartridge dries up from the inside out. To combat this problem, which is especially acute with professional fast-drying solvent inks, many wide-format printer cartridge designs contain the ink in an airtight, collapsible bag that requires no vent. The bag merely shrinks until the cartridge is empty.

The frequent cleaning conducted by some printers can consume quite a bit of ink and has a great impact on cost-per-page determinations.

Clogged nozzles can be detected by printing a standard test pattern on the page. Some software workaround methods are known for re-routing printing information from a clogged nozzle to a working nozzle.

Advantages

Compared to earlier consumer-oriented color printers, inkjets have a number of advantages. They are quieter in operation than impact dot matrix

Dot matrix printer

A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter...

or daisywheel printers. They can print finer, smoother details through higher printhead resolution, and many consumer inkjets with photographic-quality printing are widely available.

In comparison to more expensive technologies like thermal wax

Thermal transfer printer

A thermal transfer printer is a printer which prints on paper by melting a coating of ribbon so that it stays glued to the material on which the print is applied. It contrasts with direct thermal printing where no ribbon is present in the process...

, dye sublimation

Dye-sublimation printer

A dye-sublimation printer is a computer printer which employs a printing process that uses heat to transfer dye onto medium materials such as a plastic card, paper, or fabric. The sublimation name is applied because the dye transitions between the solid and gas states without going through a...

, and laser printing

Laser printer

A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

, inkjets have the advantage of practically no warm up time, and lower cost per page. However, low-cost laser printers can have lower per-page costs, at least for black-and-white printing, and possibly for color.

For some inkjet printers, monochrome ink sets are available either from the printer manufacturer or from third-party suppliers. These allow the inkjet printer to compete with the silver-based photographic papers traditionally used in black-and-white photography, and provide the same range of tones – neutral, "warm" or "cold". When switching between full-color and monochrome ink sets, it is necessary to flush out the old ink from the print head with a cleaning cartridge. Special software or at least a modified device driver

Device driver

In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....

are usually required, to deal with the different color mapping

Color mapping

Color mapping is a function that maps the colors of one image to the colors of another image. A color mapping may be referred to as the algorithm that results in the mapping function or the algorithm that transforms the image colors...

Disadvantages

Inkjet printers may have a number of disadvantages:

The ink is often very expensive. (For a typical OEM
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...

cartridge priced at $15, containing 5 mL of ink, the ink effectively costs $3000 per liter, or $8000 per gallon.) According to the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

(2003), "The cost of ink has been the subject of an Office of Fair Trading
Office of Fair Trading
The Office of Fair Trading is a not-for-profit and non-ministerial government department of the United Kingdom, established by the Fair Trading Act 1973, which enforces both consumer protection and competition law, acting as the UK's economic regulator...

investigation. Which? magazine
Which?
Which? is a product-testing and consumer campaigning charity with a magazine, website and various other services run by Which? Ltd ....

has accused manufacturers of a lack of transparency about the price of ink and called for an industry standard for measuring ink cartridge performance".
Many "intelligent" ink cartridges contain a microchip
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

that communicates the estimated ink level to the printer; this may cause the printer to display an error message, or incorrectly inform the user that the ink cartridge is empty. In some cases, these messages can be ignored, but some inkjet printers will refuse to print with a cartridge that declares itself empty, to prevent consumers from refilling cartridges. For example, Epson embeds a chip which prevents printing when the chip claims the cartridge is empty, although a researcher who over-rode
Manual override
A manual override is a mechanism wherein control is taken from an automated system and given to the user. For example, a manual override in photography refers to the ability for the human photographer to turn off the automatic aperture sizing, automatic focusing, or any other automated system on...

the system found that in one case he could print up to 38% more good quality pages, even though the chip stated that the cartridge was empty.
The lifetime of inkjet prints produced by inkjets using aqueous inks is limited; they will eventually fade and the color balance may change. On the other hand, prints produced from solvent-based inkjets may last several years before fading, even in direct sunlight, and so-called "archival inks" have been produced for use in aqueous-based machines which offer extended life.
Because the ink used in most consumer inkjets is water-soluble, care must be taken with inkjet-printed documents to avoid even the smallest drop of water, which can cause severe "blurring" or "running." Similarly, water-based highlighter
Highlighter
A highlighter is a felt-tip pen which is used to draw attention to sections of documents by marking them with a vivid, translucent colour.A typical highlighter is fluorescent yellow, coloured with pyranine.-History:...

markers can blur inkjet-printed documents.
The very narrow inkjet nozzles are prone to clogging. The ink consumed cleaning them - either during cleaning invoked by the user, or in many cases, performed automatically by the printer on a routine schedule - can account for a significant proportion of the ink used in the machine.

These disadvantages have been addressed in a variety of ways:

Third-party ink suppliers sell ink cartridges at significant discounts (at least 10%−30% off OEM cartridge prices, sometimes up to 80%), and also bulk ink and cartridge self-refill kits at even lower prices.
Many vendors' "intelligent" ink cartridges have been reverse-engineered. It is now possible to buy inexpensive devices to reliably reset such cartridges to report themselves as full, so that they may be refilled many times.
Print lifetime is highly dependent on the quality and formulation of the ink as well as the paper chosen. The earliest inkjet printers, intended for home and small office applications, used dye-based inks. Even the best dye-based inks are not as durable as pigment-based inks, which are now available for many inkjet printers.
Many inkjet printers now utilize pigment based ink which is water insoluble.
Inkjet nozzles sometimes may be cleaned and unclogged by soaking in shallow water or another solvent for 1 minute.

Third-party ink and cartridges

The high cost of OEM ink cartridges and the intentional obstacles to refilling them have been addressed by the growth of third-party ink suppliers. Many printer manufacturers discourage customers from using third-party inks, stating that they can damage the print heads due to not being the same formulation as the OEM inks, cause leaks, and produce inferior-quality output (e.g. of incorrect color gamut). Consumer Reports
Consumer Reports
Consumer Reports is an American magazine published monthly by Consumers Union since 1936. It publishes reviews and comparisons of consumer products and services based on reporting and results from its in-house testing laboratory. It also publishes cleaning and general buying guides...

has noted that some third-party cartridges may contain less ink than OEM cartridges, and thus yield no cost savings, while Wilhelm Imaging Research

Wilhelm Imaging Research

Wilhelm Imaging Research, run by Henry Wilhelm, is an image testing company that provides contract testing to clients on the stability and preservation of traditional and digital color photographs and motion pictures. The company publishes brand name-specific permanence data for desktop and...

claims that with third-party inks the lifetime of prints may be considerably reduced. However, an April 2007 review showed that, in a double-blind

Double-blind

A blind or blinded experiment is a scientific experiment where some of the people involved are prevented from knowing certain information that might lead to conscious or subconscious bias on their part, invalidating the results....

test, reviewers generally preferred the output produced using third-party ink over OEM ink. In general, OEM inks have undergone significant system reliability testing with the cartridge and print-head materials, whereas R&D efforts on third-party ink material compatibility is likely to be significantly less. Some inkjet manufacturers have tried to prevent cartridges being refilled using various schemes including fitting smart chips to the cartridges that can detect when the cartridge has run out of ink and prevent the operation of a refilled cartridge.

The warranty on a printer may not apply if the printer is damaged by the use of non-approved supplies. In the US the Magnuson–Moss Warranty Act is a federal law which states that warrantors can not require that only brand name parts and supplies be used with their product, as some printer manufacturers imply. However, this would not apply if non-approved items cause damage.

Overall expense

Most inkjet printers cost less than laser printer

Laser printer

s to purchase, but their cost per page printed is usually significantly higher. If the number of prints produced over the life of a printer is not very small, the total cost of ownership

Total cost of ownership

Total cost of ownership is a financial estimate whose purpose is to help consumers and enterprise managers determine direct and indirect costs of a product or system...

—purchase price, consumables, maintenance, and all other costs—may be higher for an inexpensive inkjet than a laser printer.

Particularly for printers not used frequently, there are additional costs due to ink wastage in cleaning required with intermittent use, and possible replacement of cartridges which are clogged due to lack of use although not empty.

Inkjet printers are often preferred, particularly for home use, due to their low purchase price and relatively small size. The best photo-quality inkjet printers may produce better quality output than colour laser printers. Laser printers are usually preferred in an office environment with higher printing volume.

Underlying business model

A common business model for inkjet printers involves selling the actual printer at or below production cost, while dramatically marking up the price of the (proprietary) ink cartridges (a profit model called "Freebie marketing

Freebie marketing

Freebie marketing, also known as the razor and blades business model, is a business model wherein one item is sold at a low price in order to increase sales of a complementary good, such as supplies or software...

"). All current inkjet printers attempt to enforce this product tying using microchips

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

in the cartridges to hinder the use of third-party or refilled ink cartridges. The microchips monitor usage and report the ink remaining to the printer. Some manufacturers also impose "expiration dates". When the chip reports that the cartridge is empty (or out of date) the printer stops printing. Even if the cartridge is refilled, the microchip will indicate to the printer that the cartridge is depleted. For many models (especially from Canon), the 'empty' status can be overridden by entering a 'service code' (or sometimes simply by pressing the 'start' button again). For some printers, special circuit "flashers" are available that reset the quantity of remaining ink to the maximum. Some manufacturers, most notably Epson and Hewlett Packard, have been accused of indicating that a cartridge is depleted while a substantial amount of ink remains. A 2007 study found that most printers waste a significant quantity of ink when they declare a cartridge to be empty. Single-ink cartridges were found to have on average 20% of their ink remaining, though actual figures range from 9% to 64% of the cartridge's total ink capacity, depending on the brand and model of printer. This problem is further compounded with the use of one-piece multi-ink cartridges, which are declared empty as soon as one color runs low. Of great annoyance to many users are those printers that will refuse to print documents requiring only black ink, just because one or more of the color ink cartridges is depleted.

In recent years, many consumers have begun to challenge the business practices of printer manufacturers, such as charging up to $8,000 per gallon for printer ink. Alternatives for consumers are cheaper copies of cartridges, produced by third parties, and the refilling of cartridges, using refill kits. Due to the large differences in price caused by OEM markups, there are many companies selling third-party ink cartridges. Most printer manufacturers discourage refilling disposable cartridges or using aftermarket copy cartridges, and say that use of incorrect inks may cause poor image quality due to differences in viscosity, which can affect the amount of ink ejected in a drop, and color consistency, and can damage the printhead. Nonetheless, the use of alternative cartridges and inks has been gaining in popularity, threatening the business model of printer manufacturers. Printer companies such as HP, Lexmark

Lexmark

, and Epson have used patents and the DMCA to launch lawsuits against third-party vendors. An anti-trust class-action lawsuit was launched in the US against HP and office supply chain Staples Inc., alleging that HP paid Staples $100 million to keep inexpensive third-party ink cartridges off the shelves.

In Lexmark Int'l v. Static Control Components

Lexmark Int'l v. Static Control Components

Lexmark International, Inc. v. Static Control Components, Inc., 387 F.3d 522 , was an American legal case involving the computer printer company Lexmark, which had designed an authentication system using a microcontroller so that only authorized toner cartridges could be used...

, Case No. 03-5400 (6th Cir. Oct. 26, 2004) (Sutton, J.) the United States Court of Appeals for the Sixth Circuit

United States Court of Appeals for the Sixth Circuit

The United States Court of Appeals for the Sixth Circuit is a federal court with appellate jurisdiction over the district courts in the following districts:* Eastern District of Kentucky* Western District of Kentucky...

ruled that circumvention of this technique does not violate the Digital Millennium Copyright Act

Digital Millennium Copyright Act

The Digital Millennium Copyright Act is a United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization . It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures that control access to...

. The European Commission

European Commission

The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....

also ruled this practice anticompetitive: it will disappear in newer models sold in the European Union. While the DMCA case dealt with copyright protection, companies also rely on patent protection to prevent copying and refilling of cartridges. For example, if a company devises all of the ways in which their microchips can be manipulated and cartridges can be refilled and patents these methods, they can prevent anyone else from refilling their cartridges. Patents protecting the structure of their cartridges prevent the sale of cheaper copies of the cartridges. For some printer models (notably those from Canon) the manufacturer's own microchip can be removed and fitted to a compatible cartridge thereby avoiding the need to replicate the microchip (and risk prosecution). Other manufacturers embed their microchips deep within the cartridge in an effort to prevent this approach.

In 2007 Eastman Kodak

Eastman Kodak

Eastman Kodak Company is a multinational imaging and photographic equipment, materials and services company headquarted in Rochester, New York, United States. It was founded by George Eastman in 1892....

entered the inkjet market with its own line of All-In-One printers based on a marketing model that differed from the prevailing practice of selling the printer at a loss while making large profits on replacement ink cartridges. Kodak claimed that consumers could save up to 50 percent on printing by using its lower cost cartridges filled with the company’s proprietary pigmented colorants while avoiding the potential problems associated with off-brand inks.http://www.businessweek.com/magazine/content/07_08/b4022048.htm

Professional inkjet printers

In addition to the widely-used small inkjet printers for home and office, there are professional inkjet printers, some for "page-width" format printing and many for wide format printing. Page-width format means that the print width ranges from about 8.5" to 37" (about 20 cm to 100 cm). "Wide format" means print width ranging from 24" up to 15' (about 75 cm to 5 m). The most common application of page-width printers is in printing high-volume business communications that do not need high-quality layout and color. Particularly with the addition of variable data

Variable Data Printing

Variable-data printing is a form of digital printing, including on-demand printing, in which elements such as text, graphics and images may be changed from one printed piece to the next, without stopping or slowing down the printing process and using information from a database or external file...

technologies, the page-width printers are important in billing, tagging, and individualized catalogs and newspapers. The application of most wide format printers is in printing advertising graphics; a lower-volume application is printing of design documents by architects or engineers.

Another specialty application for inkjets is producing prepress

Prepress

Prepress is the term used in the printing and publishing industries for the processes and procedures that occur between the creation of a print layout and the final printing...

color proofs for printing

Printing

Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....

jobs created digitally. Such printers are designed to give accurate color rendition of how the final image will look (a "proof") when the job is finally produced on a large volume press such as a four-colour offset lithography press. An example is an Iris printer

Iris printer

An IRIS printer is a large-format color inkjet printer introduced in 1987 by IRIS Graphics of Bedford, Massachusetts and currently manufactured by the Graphic Communications Group of Eastman Kodak, designed for prepress proofing...

, whose output is commonly called "iris proofs" or just "irises".

The largest-volume supplier is Hewlett-Packard

Hewlett-Packard

, which supply over 90 percent of the market for printers for printing technical drawings. The major products in their Designjet series are the Designjet 500/800, the Designjet T Printer series (including the T1100 & T610), the Designjet 1050 and the Designjet 4000/4500. They also have the HP Designjet 5500, a six-color printer that is used especially for printing graphics as well as the new Designjet Z6100 which sits at the top of the HP Designjet range and features an eight colour pigment ink system .

Epson, Kodak and Canon

Canon Inc.

also manufacture wide-format printers, sold in much smaller numbers than standard printers. Epson has a group of 3 Japanese companies around it that predominantly use Epson piezo printheads and inks: Mimaki, Roland, and Mutoh

Mutoh Europe nv

-Business Summary:*EMEA Headquarters*Established August 1990*Located in Oostende, Belgium*Core business: digital Wide-format printer , sign cutting Plotters and CAD...

.

Scitex Digital Printing developed high-speed, variable-data

Variable Data Printing

, inkjet printers for production printing, but sold its profitable assets associated with the technology to Kodak in 2005 who now market the printers as Kodak Versamark(tm) VJ1000, VT3000, and VX5000 printing systems. These roll-fed printers can print at up to 1000 feet per minute.

Professional high-volume inkjet printers are made by a range of companies. These printers can range in price from US$35,000 to $2 million. Carriage widths on these units can range from 54" to 192" (about 1.4 to 5 m), and ink technologies tend toward solvent, eco-solvent and UV-curing as opposed to water-based (aqueous) ink sets. Major applications where these printers are used are for outdoor settings for billboards, truck sides and truck curtains, building graphics and banners, while indoor displays include point-of-sales displays, backlit displays, exhibition graphics and museum graphics.

The major suppliers for professional wide- and grand-format printers include: Agfa Graphics, LexJet

LexJet

LexJet Corporation is a manufacturer and direct provider of materials and equipment utilized in wide-format inkjet printing. LexJet's primary markets are wide-format commercial print-for-pay companies, companies and organizations with in-house printing departments and digital photographers. LexJet...

, Grapo, Inca, Durst, Océ

Océ

Océ N.V. is a Netherlands-based company that develops, manufactures and sells printing and copying hardware and related software. The offering includes office printing and copying systems; production printers and wide format printing systems for both technical documentation and color display...

, NUR (now part of Hewlett-Packard

Hewlett-Packard

), Lüscher, VUTEk, Zünd, Scitex Vision

Scitex Vision

Scitex Vision, was part of Scitex Corporation Ltd. It was an Israel-based company that specialized in producing equipment for large- and very-large-format printing on both paper and specialty materials...

(now part of Hewlett-Packard

Hewlett-Packard

), Mutoh

Mutoh Europe nv

-Business Summary:*EMEA Headquarters*Established August 1990*Located in Oostende, Belgium*Core business: digital Wide-format printer , sign cutting Plotters and CAD...

, Mimaki, Roland DG], Seiko I Infotech, Sun Innovations, Leggett and Platt, Agfa, Raster Printers, DGI and MacDermid ColorSpan (now part of Hewlett-Packard

Hewlett-Packard

)

Printing of functional materials

Three-dimensional printing
3D printing
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is...

constructs a prototype by "printing" appreciably thick cross-sections of material on top of one another.
U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

Patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

6,319,530 describes a "Method of photocopying an image onto an edible web for decorating iced baked goods". In other words, this invention
Invention
An invention is a novel composition, device, or process. An invention may be derived from a pre-existing model or idea, or it could be independently conceived, in which case it may be a radical breakthrough. In addition, there is cultural invention, which is an innovative set of useful social...

enables one to inkjet print a food-grade color photograph
Photograph
A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...

on a birthday cake
Birthday cake
The birthday cake has been an integral part of the birthday celebrations in Western cultures since the middle of the 19th century. Certain rituals and traditions, such as singing of birthday songs, associated with birthday cakes are common to many Western cultures. The Western tradition of adding...

's surface. Many bakeries now carry these types of decorations, which are printable using edible inks and dedicated inkjet printers. Edible ink printing
Edible ink printing
Edible ink printing, is the process of creating preprinted images with edible food colors on to various confectionery products such as cookies, cakes, or pastries. Edible Image designs can either be preprinted, or created with an edible printer, a specialty device which transfers an image onto a...

can be done using normal home use inkjet printers like Canon Bubble Jet printers with edible ink cartridges installed, and using rice paper or frosting sheets.
Inkjet printers and similar technologies are used in the production of many microscopic items. See Microelectromechanical systems
Microelectromechanical systems
Microelectromechanical systems is the technology of very small mechanical devices driven by electricity; it merges at the nano-scale into nanoelectromechanical systems and nanotechnology...

.
Inkjet printers are used to form conductive traces for circuits, and color filters in LCD and plasma displays.
Inkjet printers, especially models produced by Dimatix (now part of Fujifilm), Xennia Technology and Pixdro, are in fairly common use in many labs around the world for developing alternative deposition methods that reduce consumption of expensive, rare, or problematic materials. These printers have been used in the printing of polymer, macromolecular, quantum dot, metallic nanoparticles, carbon nanotubes etc. The applications of such printing methods include organic thin-film transistors, organic light emitting diodes, organic solar cells, sensors, etc.
Inkjet technology is used in the emerging field of bioprinting.

Alternative trade names

Images produced on inkjet printers are sometime sold under other names since the term is associated with words like "digital", "computers", and "everyday printing", which can have negative connotations in some contexts. These trade names or coined names are usually used in the fine arts reproduction field. They include:

Digigraph
Iris prints
Iris printer
An IRIS printer is a large-format color inkjet printer introduced in 1987 by IRIS Graphics of Bedford, Massachusetts and currently manufactured by the Graphic Communications Group of Eastman Kodak, designed for prepress proofing...
Giclée
Giclée
Giclée , is a neologism coined in 1991 by printmaker Jack Duganne for fine art digital prints made on ink-jet printers. The name originally applied to fine art prints created on IRIS printers in a process invented in the late 1980s but has since come to mean any high quality ink-jet print and is...
Cromalin

External links

Article: Printing Enters The Jet Age
Inkjet Printing of Ceramic Tiles
Large Format Review Highly regarded wide format inkjet print industry News website - Updated daily

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Technologies

Continuous inkjet (CIJ)

Thermal (thermal DOD inkjet)

Piezoelectric (piezoelectric DOD inkjet)

Ink formulations

Head design

Fixed head

Disposable head

Cleaning mechanisms

Advantages

Disadvantages

Third-party ink and cartridges

Overall expense

Underlying business model

Professional inkjet printers

Printing of functional materials

Alternative trade names

See also

External links