# The Computer Revolution/Peripherals/Printers
## The printer
### A bit of history

In 1938, Chester Carlson invented a dry printing process called electrophotography commonly called a Xerox, the foundation technology for laser printers to come. For years, nobody seemed to pay any interest to Carlson's invention. From 1939 to 1944 Carlson was turned down by more than 20 companies. Finally, in 1947 the inventor managed to facilitate a deal with a small, completely unknown photo-paper company Haloid (later renamed Xerox), giving them the right to develop a xerographic machine. In 1959, twenty years after Carlson invented xerography, the first Xerox office copier 914 was presented to the public.
In 1953, the first high-speed printer was developed by Remington-Rand.
According to Xerox, the original laser printer called EARS was developed at the Xerox Palo Alto Research Center beginning in 1969 and completed in November, 1971. Xerox Engineer, Gary Starkweather adapted Xerox copier technology adding a laser beam to it to come up with the laser printer.
According to IBM, "the very first IBM 3800 was installed in the central accounting office at F. W. Woolworth’s North American data center in Milwaukee, Wisconsin in 1976." The IBM 3800 Printing System was the industry’s first high-speed, laser printer. A laser printer that operated at speeds of more than 100 impressions-per-minute. It was the first printer to combine laser technology and electrophotography according to IBM.
In 1992, Hewlett-Packard released the popular LaserJet 4, the first 600 by 600 dots per inch resolution laser printer.
In 1962 Chuck Winston's electrostatic deflected droplets single nozzle inkjet patent 3,060,429 issued. This inkjet printer did not show up commercially until 1966 when AT&T's Long Lines Project 176 produced and delivered the Inktronic 100 WPM TTY printer. The wax ink had to be heated to achieve proper viscosity for jetting. It printed on paper but produced characters that lay on the paper. The paper could be heated to make the wax ink soak into the paper and make it impossible to see. This would have been considered early 3D printing if the concept of graphics or relief characters was imagined. This same technology tested Braille character printing but the wax separated from surface too easily.
In 1971 Johannes F Gottwald Liquid Metal Recorder using a low melting temperature alloy and magnetic deflected droplets single nozzle inkjet patent US3596285 issued. This inkjet patent was never commercially produced but it did prove actual metal characters were printed on a metal substrate and fell of onto the table. This was the first time liquid metal was jetted and it could be recognized as an example of the first 3D metal ink printing. The metal printed characters were intended to be used for displaying stock market data. One unique feature of this technology was the characters could be put back into the heated ink reservoir and melted for printing again.
In 1972 Steve Zoltan's Drop-On-Demand single nozzle inkjet patent 3,683,212 was issued. This allowed single drop ejection instead of the earlier continuous stream nozzles. This glass nozzle technology was installed on a Quip Inkjet facsimile printer at Exxon Office Systems in 1979 and then inspired the improved Teflon molded nozzle material use in Howtek, Inc., Pixelmaster full color Thermoplastic ink printer product introduced in 1986. It used 32 single nozzles in a rotary printhead and printed on standard office paper sheet. Accidental printing on paper multiple times produced raised characters. These raised print characters were jokingly named 'alphabet soup' and had been seen at Exxon Office Systems years before. The idea of using raised print technology was introduced at Howtek, Inc., by another inventor, Al Hock and it lead to but didn't produce a 3D patent idea until Richard R. Helinski 1992 patent US5136515A, Method and Means for Constructing Three-Dimensional Articles by Particle deposition. A company named C.A.D.-Cast, Inc., renamed to Visual Impact Corporation in New Hampshire was formed in 1989 to show "the Sculptor" idea but it dissolved in 1995. There is a video of this 3D printing technology at the 3dinkjetmuseum.com The Helinski patent was finally licensed to Sanders Prototype, Inc. and then later sold to 3D Systems, Inc. Single jet nozzle technology is poorly understood and not well known in the 3D Printing industry today. Inkjet printing has a rich history and there are a number of controversy's that could be discussed here.

### Printing technology

Printers are routinely classified by the underlying print technology they employ; numerous such technologies have been developed over the years.
The choice of print engine has a substantial effect on what jobs a printer is suitable for, as different technologies are capable of different levels of image/text quality, print speed, low cost, noise; in addition, some technologies are inappropriate for certain types of physical media (such as carbon paper or transparencies).
Another aspect of printer technology that is often forgotten is resistance to alteration: liquid ink such as from an inkjet head or fabric ribbon becomes absorbed by the paper fibers, so documents printed with a liquid ink sublimation printer are more difficult to alter than documents printed with toner or solid inks, which do not penetrate below the paper surface.
Checks should either be printed with liquid ink or on special "check paper with toner anchorage". For similar reasons carbon film ribbons for IBM Selectric typewriters bore labels warning against using them to type negotiable instruments such as checks. The machine-readable lower portion of a check, however, must be printed using MICR toner or ink. Banks and other clearing houses employ automation equipment that relies on the magnetic flux from these specially printed characters to function properly.

#### Speed

Print speed is how long it will take a document to print. It is usually measured as pages printed per minute (ppm). There are many factors that can depend on how long it takes for something to print. Some factors are selected print resolutions and the content being printed. For example, to print color documents takes longer than printing black-and-white pages. Also, printing images take longer than just printing a document with words. The average printer prints about 15 to 35 pages per minute and a photocopier prints about 40 to 100 ppm. When you are choosing a printer you really need to consider the speed that it prints at because you need one that will suite your use. For example, for a business you would want fast speeds but for personal use it depends on you.

#### Choosing the correct "paper"

It is important to use the adequate paper with the type of printer you are using. If you are using a laser printer, you want to use paper called laser paper, this way you will get the best possible quality out of your printer. Use toner efficiently. Likewise, if you are using an ink jet printer, you want to use ink jet paper. This paper is treated so that the ink stays on the surface, that way your ink should last longer than if you were just using regular copied paper. When using large format printers, be sure to select the right paper settings for the paper you are using. This will give you the best quality in your print, and use your ink more efficiently.

### Dot-matrix printer

The dot matrix printer, also known as a dot character printer, forms each character as a group of small dots, using a group of wires located in the printing element. It is usually used these days to print multipart forms (like carbon copies) and address labels. The tractor and sprocket mechanism in these types of printers can handle thicker media better than laser and ink jet printers.
The dot matrix printer uses one or two columns of dot hammers that move across the paper. The hammers hit the ribbon into the paper which causes the ink to be deposited, similarly to a typewriter. The more hammers in the printer the higher the resolution of the resulting image. Though those wishing to have any sort of resolution with anything other than text would do better to use one of the other varieties of printer since Dot matrix printers can be as expensive but not as multifunctional than the inkjet or laser printers. Another big disadvantage is the noise factor output of the dot matrix printers.
Since Inkjet and laser printers are quite fast with the printing, the print speeds are based on ppg (pages per minute), which is usually indicated on the specifications. Dot matrix printers are different in that the speed of the printer itself is based on cps (characters per second) and varies between 50 to 500 cps depending on the resolution desired. Dot matrix printers are able to print a few pages per minute but will not equal to the amount of pages that an inkjet and laser printers can print.

### Ink jet Printers

* Ink
The ink used in Ink jet printers may be in a liquid or solid form. The most common ink comes in small cartridges which are compatible for your printer. However the cartridges do vary, depending on your printer the manufacturer will designate a brand for your printer and continue on to explain the reason for purchasing a new cartridge. But not all cartridges need to be discarded, with a growing number of purchased ink jet printers across the world. People are turning to a more inexpensive way of refilling their ink. Through cartridges which are refillable and even in some cases, are permanently installed. These new techniques of refilling your printer have proven to be less expensive than purchasing a brand new cartridge and allow the same quality of printing. Although in some cases manufacturers have warned against this, since it could void your warranty. Solid inks must be melted to reach the liquid state. Wax was the ink of choice in the Inktronic printer manufactured in mid 1960's by AT&T, Teletype, Corp. A metal alloy ink composed of Bismuth, Tin, Lead and either Cadmium or Indium was later used in the Liquid Metal Recorder in 1971 also from AT&T, Teletype. Hot melt inks were used in the Howtek, Inc Pixelmaster and produced the first color images and text on plain paper in the mid 1980's. This same solid thermoplastic ink became the ink for the first production 3D inkjet printer manufactured by Sanders Prototype, Inc, Modelmaker 6 Pro in 1994 by mixing yellow and cyan inks to produce the popular green 3D color. This 3D Inkjet printer also used wax inks as easily removable support structures for it's 3D models.
* Print
Inkjet printers work in a sense that the printer distributes hundreds of thousands of ink droplets onto your paper or into your 3D model, eventually forming an image with high quality or a model with high precision. Each droplet comes from a nozzle (a printer can contain from one to many hundred nozzles) and is then sprayed down onto the page or model. An early drawback of this system, was that the ink is still wet when document is fed out and if touched immediately the ink swill smear blemishing the image. Faster drying inks and quick cooling solid inks rely on time delays to compensate for this problem.
* Quality and the right inkjet printer
Inkjet printers are the basic standard of quality, depending on what type of inkjet printer and purpose you’ll use your printer for. If the printer is used for office use then a multi-functional printer is capable of scanning and faxing, which should yield a good quality for printing. But if you’re a photographer and print high quality photos, than a snapshot printer is more practical, since it’s specially designed to print out high quality photos with good saturation of color. For the best quality relating to printing graphics or high quality text then a laser printer is the best candidate. However, laser printers do not incorporate the use of inkjet technology and are more expensive.
Inkjet became popular in 3D printers used by jewelry manufacturers in the 1990's because wax carvers were hard to find or were unreliable at times and couldn't produce exact replica's of a design. The precise placement of measured size drops that could print each 3D model exactly as designed and could be investment cast was cost priced perfectly. The 3D Inkjet technology eliminated the wax carver, automated the jewelry business and was right for a small mom and pop shop. The owner operator only had to learn CAD because the finished 3D models fit exactly into the work flow of investment casting. The 3D Inkjet printer was not always reliable but was serviceable by the shop owner who couldn't live without it. Customers could see the wax model and request design changes before the finished model was cast in some cases with gems in place. The price of finished jewelry allowed the jeweler to own a 3D printer and make a good profit.

### Laser Printer

A laser printer is a type of computer printer that quickly produces high quality text and graphics on plain paper; compare with other type of printers, such as impact printers. The first laser printer was called EARS, was developed by Xerox and was completed in November 1971. Laser printers can mix text and graphics, including different fonts, character sizes, and images. The laser printer uses drum and laser technology: the laser shoots shapes and letters onto the drum, from these images created from the lasers, the drum has knowledge of where to pick up the black powder, other wise known as toner. The light produced by the laser changes the electrical charge of the drum temporarily. Toner is used by laser printers rather than liquid ink. After the drum has picked up the powder it is applied to the paper still in a powder form. The final step of laser printing is the heat and pressure applied to the paper. By heating the paper the powder melts into an ink making permanent impressions on the paper in the form the laser mapped out. Advantages of laser printers over inkjet printers include faster print speed, no smearing, higher resolution,and lower cost . The resolution of laser printers ranges from 300dpi to 1200dpi which allows the resolution to be one of the major advantages of the laser printer. The low cost is only true for monochrome laser printers, those only using black toner, but when purchasing a laser printer with multiple toner ability the cost tends to skyrocket drastically. In terms of graphics and the laser jet printer, the quality is good but the amount of memory required by the printer is very large and without a high memory printer the graphics will lack quality. The speed of laser printer ranges from 4-20 pages per minute, with the average being on the lower end at 6 pages per minute
Laser printers have so many different components that a huge problem becomes the paper jams. The computer within tells you through a series of screens where the paper jam is or if the toner is low. It can also tell you what color is low, paper is low if it's time to do maintenance. You can report a problem via the printers computer.
Most laser printers use high quality slightly heavy paper in order to produce high quality printing. Printers can now hole punch, tri-fold and staple. Printers come with scanners. You can chose to scan to your desktop or an email address.

### 3D printer

A 3D printer, unlike a normal 2D printer that prints on paper, prints a slice or cross-section of a CAD designed 3D model one layer at a time on a surface using molten plastic or other materials. This process adds the material until the 3D version is formed. Another name for this process is called Additive Manufacturing. There are a number of technologies that can produce 3D models. One technology is "fused deposition modeling (FDM)". This type of 3D printing is normally used when a prototype of a new product is under development or for creating a 3D version of an architectural vision. This process is extremely easy compared to cutting boards and gluing them together to create a small model of a building. More advanced 3D printers are able to use different colors and different materials and in larger sizes. Some only print in one color and the output would then have to be painted. This process is not fast for mass production yet since individual models are printed in layers. But it is so advanced that if you have interlocking parts in a output you desire and still want it to be functional, it can print that. An example could be a wrench with a tightening grip. A link is provided for the process and the output of a 3D printer that is producing this type of wrench. http://www.youtube.com/watch?v=WmDz7Q9_h6c

### UV printer

Xerox is working on an inkless printer which will use a special reusable paper coated with a few micrometres of UV light sensitive chemicals. The printer will use a special UV light bar which will be able to write and erase the paper. As of early 2007 this technology is still in development and the text on the printed pages can only last between 16–24 hours before fading.
Barcode Label and Postage Printers -
Barcode printers enable businesses and other organizations to print custom barcode on price tags, shipping labels, and other documents for identification or pricing purposes. Most barcode printers can print labels in a variety of barcode standards such as RFID tags embedded in labels. There are other types of labels for examples envelopes, packages, file folders use regular label printers and that can be printed from personal computers. There is also another type of printers that can be use for postage printers and that can print electronic postage also called e-stamps. E-stamps are valid postage stamps that can be printed once a postage allotment has been purchased via the Internet or from e-stamp services from a vendor. Postage values can be deducted from your allotment as you print the e-stamps. Some e-stamps allow stamps to be printed directly onto shipping labels and envelopes using laser or ink-jet printers.

### Uses
#### Photo printer

A photo printer is colored printers that are designed to print photographs. Photo printers allow you to plug the camera directly into the printer so that you are able to print right from your camera; no downloading necessary! Using photo printers allows you to still make any necessary changes needed. Choosing pictures sizes, editing, and cropping are all some of the changes that can still be made. Printing your photos through your house saves a lot of money for you.
Photo printers mean you can finally produce true photo quality, you can print your precious memories with confidence. You can't distinguish their output from photos that were printed from film in the conventional process. There are essentially three categories of photo printers and they are ink jet photo printers, second is dedicated photo printers and lastly is the professional photo printers.
* Inkjet photo printers
These offer at least one photo feature but can also function as all-purpose printers. They print from business applications reasonably well, though often at a very slow pace. This is the category to consider if you want a single, all- purpose printer. You should also consider it if you want a second printer just for photos.
* Dedicated photo printers
These are typically limited to printing on special-purpose—usually glossy—paper. They may also print only on relatively small paper sizes, often 4 by 6 inches. To date, you can find these in both ink jet and thermal-dye varieties.
* Professional photo printers
These printers may also be dedicated photo printers, but their key characteristic is that they offer at least tabloid-size output (11 by 17 inches). Some can print photos at much larger sizes.

## References

* ↑ Abagnale, Frank (2007). "Protection Against Check Fraud" (PDF). abagnale.com. Retrieved 2007-06-27.
* ↑ Xerox Inkless Printer - TFOT
* HP printer
* Here is a link that lists some of the more important features when buying a photo printer: http://www.pcmag.com/article2/0,1895,1645744,00.asp