Inkjet Printers

By-Harshita VedVini GargNeerav MahadaneAnkit Gadwe

Printer-

•A Printer is an electromechanical device which converts the text and graphical documents from electronic form to the physical form and gives output.

A. Based on to the Printing Speed Serial printers- • Prints the characters one by one.• Speed is expressed in characters per second • Can reach a few hundreds of characters per

second. Line printers-• Prints all the characters in a line simultaneously. • Speed is expressed in lines per minute.• Can reach several thousands of lines per minute. Page printers- • Contains buffer memories for one or more pages.• Printing is done by preparing the image to be

printed for an entire page in memory, after which the paper is advanced continuously during printing.

• Their speed may reach 50,000 lines per minute.

CLASSIFICATION OF PRINTERS

B. Based on to the Printing Quality• There are three quality levels of the printed

documents: Low or draft quality- • Saves ink.• Allow the user to see what the print job would look

like before printing the final copy. Medium or near-letter quality- • Able to print with the quality typically expected from

a business typewriter such as an ibm selectric.• Letters are clearer and less jagged than a low

quality printer. High or letter-quality- • High quality output

in printed from a printer linked to a word processor.• Better than above both in quality of printing.

C . BASED ON THE OPERATING PRINCIPLE

There are two important categories: Impact printers –• Work by striking head or needle against

an ink ribbon to make a mark on the paper.

• This includes dot-matrix printers, daisy-wheel printers, and line printers.

• Advantage: allow to make several copies simultaneously.

• Drawback: relatively slow and are noisy.

2. Non-impact printers-• Have fewer moving parts• No direct physical contact between the

printing mechanism and the paper. • Examples of non-impact printers are

thermal, inkjet printers.• Advantages: high speed, high quality of

the printed text or image, and low level of noise,• Disadvantage: cannot create several

copies simultaneously.

Inkjet Introduction

Inkjet printing: • Type of computer printing that recreates

a digital image by propelling droplets of ink onto paper, plastic, or other substrates.

• Most commonly used type of printer.• Ranges from small inexpensive consumer models

to very large professional machines that can cost tens of thousands of dollars.

• Came into existence in about late 1980’s.• These have become the replacement printer for

the serial dot matrix in the home cause of two main reasons:

Low PriceMore Color capabilities

Inkjet Introduction

• An Inkjet printer is any printer that places extremely small droplets of ink onto paper to create an image. 

• It produces characters by squirting a precisely controlled amount of ink onto the paper.

• Dots are extremely small usually 50-60 microns in diameter (Human Hair approx 70 microns).

• Dots are placed very precisely on the paper in a pattern up to 1440 x 720 dots per inch(dpi).

• Dots can be of different colors combined together to create photo-quality images.

Inside an INKJET PRINTERParts of typical Inkjet

Printer include:Print Head Assembly: Print Head: The core of an

inkjet printer, the print head contains a series of nozzles that are used to spray drops of ink.

Interface Ports: USB port or Serial Port like Small Computer System Interface(SCSI) port are used as Interface Ports.

Inside an inkjet printer

Paper Feed Assembly: Paper Tray/Feeder: Most Inkjet

Printers have a tray that you load the paper into. The Feeder typically snaps open at an angle on the back of the printer, allowing you to place paper in it.

Power Supply: Earlier Printers often had an external transformer, most printers sold today use a standard power supply that is incorporated into printer itself.

Inside an inkjet printer

Ink Cartridge:There are variety of cartridges

depending on the manufacturer of the printer. Eg. Multi color in one cartridge or Single color in one cartridge.

Control Circuitry: The mechanical operation of the printer is controlled by a small circuit board containing a Microprocessor and Memory.

Inkjet printer Working: A typical inkjet receives control

info from your printer driver/PC.

Either way, rollers advance a page from your paper tray (1) under a sliding print head/cartridge assembly (2).

Then, the print head stepper motor (3) kicks in, drawing the assembly on a sliding rod (4) to its starting position, usually via a belt(5).

The head's microscopic nozzles (8) —anywhere from dozens to literally thousands—are outlets for incredibly tiny ink chambers (9), which are fed by the cartridge's reservoirs.

Inkjet printer Working:

Microscopic droplets (10), measured in millionths of a millionth of a liter, fired through the nozzles.

Instead, most inkjets use "thermal" technology in which a tiny resistor (11) in an ink chamber is pulsed, as needed, with intense current, superheating the ink and vaporizing part of the droplet. The result: Terrific pressure blasts it out the nozzle and onto your page.

Features of INKJET PRINTER:

• They can print from two to four pages per minute.

• Resolution is about 360 dots per inch, therefore better printing quality is achieved.

• The operating cost is quite low, the only part that needs replacement is Ink Cartridge.

• Color inkjet printers have four ink nozzles with colors Cyan ,Magenta ,Yellow and Black, because it is possible to combine these colors to create any color in visible spectrum.

•DEPENDING ON THE DROP GENERATION METHOD:

• Three types of inkjet printers are used:

1. Continuous jet- The droplet generation head is continuously supplied with ink under pressure by a pump.

2. Intermittent jet-These printers use an ink charged electrostatically, which is supplied at a low pressure.

3. Drops-on-demand-This method is the most used on common inkjet printers. The droplets are generated individually with the help of an electric pulse that determines deformation of the nozzles’ chambers or heating of the ink.

Heat vs Vibration There are several technologies that are used for building

inkjet printers. Most common are:• Thermal: Most inkjets use thermal technology,

whereby heat is used to fire ink onto the paper. Droplet generation is achieved by very rapidly heating up the ink, with a few hundreds of Celcius per μs.

• Piezoelectric: uses a Piezo crystal at the rear of the ink reservoir. This is rather like a loudspeaker cone that flexes when an electric current flows through it. So whenever a dot is required, a current is applied to the Piezo element which then flexes and, in so doing, forces a drop of ink out of the nozzle.

Advantages:1. Initial Cost

Ink-Jet printers are one of the lowest cost products on the market.

2. QualityToday you can create images or documents with high quality by Inkjet printers.

3. SpaceCompare to laser printers, the ink jet printers have suitable size to put on the desk on your office or a small room in your home

4. TimeDifferent from laser printer, the inkjet printer do not require time to heat the machine system before print.

Disadvantages:1. Cartridge Cost

You can buy a cheap inkjet printer first but with the replacement of the cartridges in a long time, the cartridge cost can exceed the machine cost.

2. SpeedYou can only use ink-jet printer to create little volumes of documents only because inkjet printer is slower than laser one.

3. MoistureAfter creating images or documents, we must wait until those dry. Sometimes it can delay our delivery process.

4. InkThe replacement of cartridges causes some unexpected problems the printers like cartridges clogged with ink.