IT Essentials - Chapter 8 Printers

Serial

- A serial connection can be used for dot matrix printers because the printers do not require high-speed data transfer. A serial connection for a printer is often referred to as COM. Serial ports are generally found on legacy computer systems. Has 9 pins.

Cloud Printing

- Cloud printing is sending a print job to a remote printer, as shown in the figure. -- The printer could be at any location within your organization's network. Some printing companies provide software that you can install and then send print jobs to their closest location for processing. - Another cloud printing example is Google Cloud Print, which allows you to connect your printer to the web. After it is connected, you can send print jobs to your printer from anywhere that has internet access.

Printer Output Options

- Color management - Print speed

Media Control Options

- Input paper tray selection - Output path selection - Media size and orientation - Paper weight selection

Virtual Printer Characteristics

- Print software either sends the job to a file or transmits the information to a remote destination in the cloud for printing. - Print to file - Originally, print to file saved your data in a file with the .prn extension. The .prn file then could be quickly printed at any time without opening the original document. Print to file can now save in other formats, as shown in the figure. - other formats, as shown in the figure. Print to PDF - Adobe's Portable Document Format (PDF) was released as an open standard in 2008. - Print to XPS - Introduced by Microsoft in Windows Vista, the XML Paper Specification (XPS) format was meant to be an alternative to PDF. - Print to image - To prevent others from easily copying the content in a document, you can choose to print to an image file format, such as JPG or TIFF.

Color

- The color printing process uses the primary colors cyan, magenta, and yellow (CMY). - For inkjet printing, the color black serves as the base or key color. -- Thus, the acronym CMYK refers to the inkjet color printing process.

Fuser Assembly - Laser Printers

- The paper is passed through a fuser assembly that is made up of hot rollers, which melt the toner into the paper.

Carriage/Belt - Inkjet Printer Parts

- The print head and ink cartridges are located on the carriage which is attached to a belt and motor. - The belt moves the carriage back and forth across the paper as the ink is sprayed on it.

Speed and Quality

- The speed of a printer is measured in pages per minute (PPM). - Speed is also affected by the complexity of the image and the quality desired by the user. - The quality of printing is measured in dots per inch (dpi). -- The quality of printing is measured in dots per inch (dpi).

Thermal Printer Preventive Maintenance

- Thermal printers use heat to create an image on special paper. - To extend the life of the printer, dampen a cotton swab with isopropyl alcohol to clean the heating element. -- Do this on a regular basis. -- The heating element is located near the slot where the printed paper emerges. - While the printer is open, use compressed air or a lint-free cloth to remove any debris.

Reliability and Total Cost of Ownership

- Warranty - Scheduled servicing: Servicing is based on expected usage. Usage information is in the documentation or on the manufacturer's website. - Mean time between failures (MTBF): The printer should work without failing for an average length of time. This information is in the documentation or on the manufacturer's website. The total cost of ownership (TCO) includes a number of factors: - Initial purchase price - Cost of consumable supplies, such as paper and ink - Pages per month - Price per page - Maintenance costs - Warranty costs When calculating the TCO, consider the amount of printing required and the expected lifetime of the printer.

Inkjet Printers Characteristics

- easy to use and usually less expensive than laser printers. - Some advantages of an inkjet printer are initial low cost, high resolution, and they are quick to warm up. - Some disadvantages of an inkjet printer are that the nozzles are prone to clogging, ink cartridges can be expensive, and the ink is wet for a few seconds after printing.

Hardware Print Servers

A hardware print server is a simple device with a network card and memory. It connects to the network and communicates with the printer to enable print sharing. - The print server in the figure is connected to the printer by a USB cable. A hardware print server may be integrated with another device, such as a wireless router. -- In this case, the printer would connect directly to the wireless router, most likely through a USB cable. Apple's AirPort Extreme is a hardware print server. - Through the AirPrint service, the AirPort Extreme can share a printer with any device on the network. A hardware print server can manage network printing through either wired or wireless connections. - An advantage of using a hardware print server is that the server accepts incoming print jobs from devices, thereby freeing the computers for other tasks. - A hardware print server is always available to users, unlike a printer shared from a user's computer.

Laser Printers

A laser printer is a high-quality, fast printer that uses a laser beam to create an image. - advantages of a laser printer are low cost per page, high ppm, high capacity, and prints come out dry. - Some disadvantages of a laser printer are high cost of startup, and that toner cartridges can be expensive.

Automatic Document Feeder

An automatic document feeder (ADF) can be found on some laser and inkjet printers which also have the capabilities of copy machines. - These are called multi-function devices (MFDs). - When started, the ADF pulls one page of the document onto the glass surface of the platen, where it is scanned and copies are made.

Axis - 3D printer Parts

An axis is one of several bars on which the hotend nozzle travels to dispense filament. - Axis are vertical or horizontal so that the hotend nozzle can be located within a specified location in a 3D environment to "print" the object.

Toner Cartridge/Paper - Laser Printers

As the drum rotates, the laser beam draws an electrostatic image upon the drum. - This undeveloped image is passed by a supply of toner. - The toner is a negatively charged combination of plastic and metal particles. - The electrostatic charge attracts toner to the image. The drum turns and brings the exposed image in contact with the paper, which attracts the toner from the drum. - The toner cartridge and paper are the primary consumable items in a laser printer. Other parts may also be contained in the toner cartridge.

Ethernet

Connecting a printer to the network requires cabling that is compatible with both the network and the network port installed in the printer. Most network printers use an RJ-45 interface to connect to a network

Filament - 3D printer Parts

Filament is the material used in 3D printers to create objects. - Common types of filament are plastic-based: ABS, PLA, and PVA. There are even filaments made of nylon, metal, or wood.

Firewire

FireWire, also known as i.LINK or IEEE 1394, is a high-speed communication bus that is platform independent. - FireWire connects digital devices such as printers, scanners, cameras, and hard drives.

Dedicated Print Servers

For larger networking environments with multiple LANs and many users, a dedicated print server is needed to manage printing services, as shown in the figure. - A dedicated print server is more powerful than a hardware print server. -- It handles client print jobs in the most efficient manner and can manage more than one printer at a time. A dedicated print server must have the following resources to meet the requests of print clients: - Powerful processor: Because the dedicated print server uses its processor to manage and route printing information, it must be fast enough to handle all incoming requests. - Adequate storage space - A dedicated print server captures print jobs from clients, places them in a print queue, and sends them to the printer in a timely manner. This process requires the computer to have enough storage space to hold these jobs until completed. - Adequate memory - The processor and RAM handle sending print jobs to a printer. If there is not enough memory to handle an entire print job, the document is stored on the drive in the print server and printed from there. This is generally is slower than printing directly from memory.

Impact Printer Preventive Maintenance

If a consistent flaw is produced in all characters, the print head, shown in the next figure, is stuck or broken and needs to be cleaned or even replaced. - Search for procedures on dot matrix printhead cleaning to learn about this.

Impact Printer Characteristics

Impact printers have print heads that strike an inked ribbon, causing characters to be imprinted on the paper. - Dot matrix and daisy wheel are examples of impact printers. An advantage of impact printers is that the ribbon is less expensive than inkjet cartridges or laser printer toner cartridges. - They can use continuous feed or normal sheets of paper and can print carbon copies. - Disadvantages include the fact that they are noisy, the graphics are low-resolution, and they have limited color-printing capabilities. - A dot matrix printer has a print head containing pins that are surrounded by electromagnets. When energized, the pins push forward onto the ink ribbon, creating a character on the paper. - The number of pins on a print head, 9 or 24, determines the quality of the print. The highest quality of print that is produced by the dot matrix printer is referred to as near letter quality (NLQ). - Most dot matrix printers use continuous-feed paper, also known as tractor feed. - The paper has perforations between each sheet, and perforated strips on the side are used to feed the paper and to prevent skewing or shifting. - Sheet feeders that print one page at a time are available for some higher quality printers. A large roller, called the platen, applies pressure to keep the paper from slipping. - If a multiple-copy paper is used, you can adjust the platen gap to the thickness of the paper.

Software Print Servers

In some instances, the computer sharing the printer is running an operating system that is not Windows, such as Mac OS. In this case, you can use print server software. - One example is Apple's free - Bonjour Printer Server, which is a built-in service in Mac OS. It is automatically installed on a Windows computer if you install the Apple Safari Browser. -- You can also download the Bonjour Printer Server for Windows, as shown in the figure, for free from the Apple website. --- When it is downloaded and installed, the Bonjour Printer Server operates in the background, automatically detecting any compatible printers connected to the network.

Print Head - Inkjet Printer Parts

Inkjet printers use ink cartridges that spray ink onto a page through tiny holes. The tiny holes are called nozzles and are located in the print head. There are two types of inkjet nozzles: - Thermal - A pulse of electrical current is applied to heating chambers around the nozzles. The heat creates a bubble of steam in the chamber. The steam forces ink out through the nozzle and onto the paper. - Piezoelectric - Piezoelectric crystals are located in the ink reservoir at the back of each nozzle. A charge is applied to the crystal, causing it to vibrate. This vibration of the crystal controls the flow of ink onto the paper.

Wireless

Many printers come with built-in wireless capability which enables them to be connected to a Wi-Fi network. Some come equipped with the ability to connect to devices through Bluetooth pairing.

Thermal Printer Characteristics

Many retail cash registers and some older fax machines contain thermal printers. - Thermal paper is chemically treated and has a waxy quality. Thermal paper becomes black when heated. - After a roll of thermal paper is loaded, the feed assembly moves the paper through the printer. - Electrical current is sent to the heating element in the print head to generate heat. The heated areas of the print head make the image on the paper. - advantages of thermal printers are that they last a long time because there are few moving parts, their operation is quiet and there is no cost for ink or toner. However, thermal paper is expensive, it must be stored at room temperature and can degrade over time. Thermal printer images are poor quality, and color printing is not available.

Characteristics of Printers

Most printers available today are usually either laser printers using imaging drums - or inkjet printers using electrostatic spray technology. - Dot matrix printers using impact technology are used in applications that require carbon copies. - Thermal printers are commonly found in retail. Many are used to print receipts. - 3D printers are used in design and manufacturing. - Inkjet Printer - Impact Printer - 3D Printer - Thermal Printer - Laser Printer

Pickup Rollers - Laser Printers

Pickup rollers may be located in multiple areas of a printer. They move the sheet of paper out of the tray or cassette, then through the printer during the printing process.

Roller - Inkjet Printer Parts

Rollers pull paper in from the feeder.

Duplexing Assembly - Inkjet Printer Parts

Some inkjet printers can print on both sides of a page. This requires a duplexing assembly which turns a printed page over and feeds it back through the printer to be printed on the other side.

Hardware Optimization

Some printers can be upgraded to print faster and to accommodate more print jobs by adding hardware. - The hardware may include additional paper trays, sheet feeders, network cards, and expansion memory. Firmware: The procedure to upgrade firmware is similar to installing printer drivers. - Because firmware updates do not take place automatically, visit the home page of the printer manufacturer to check the availability of new firmware. Printer Memory: All printers have RAM, such as the chips shown in the figure. - Printers usually arrive from the factory with enough memory to handle jobs that involve text. -- However, print jobs involving graphics, and especially photographs, run more efficiently if the printer memory is adequate to store the entire job before it starts. -- Upgrading the printer memory increases the printing speed and enhances complex print job performance. Print Job Buffering: is when a print job is captured in the internal printer memory. - Buffering is a common feature in laser printers and plotters, as well as in advanced inkjet and dot matrix printers. -- If you receive low memory errors, this can indicate that the printer is out of memory or has a memory overload. --- In this instance, you may need more memory.

The Six Steps of the Troubleshooting Process

Step 1 - Identify the Problem Step 2 - Establish a theory of probable cause. Step 3 - Test the theory of probable cause. Step 4 - Establish a plan of action to resolve the problem and implement the solution. Step 5 - Verify full system functionality and if applicable, implement preventive measures. Step 6 - Document finding, actions, and outcomes.

Imaging Drum - Laser Printers

The central part of the laser printer is its imaging drum. - The drum is a metal cylinder that is coated with a light-sensitive insulating material. - When a beam of laser light strikes the drum, it becomes a conductor at the point where the light hits it.

1. Processing - How Laser Printing Works

The data from the source must be converted into a printable form. - The printer converts data from common languages, such as Adobe PostScript (PS) or HP Printer Command Language (PCL), to a bitmap image stored in the printer's memory. - Some laser printers have built-in Graphical Device Interface (GDI) support. - GDI is used by Windows applications to display printed images on a monitor so there is no need to convert the output to another format such as PS or PCL.

Parallel

The data transfer path is wider than the serial data transfer path, allowing data to move more quickly to or from the printer. - IEEE 1284 is the standard for parallel printer ports. - Enhanced Parallel Port (EPP) and Enhanced Capabilities Port (ECP) are two modes of operation within the IEEE 1284 standard that allow bidirectional communication. - A parallel connection for a printer is often referred to as LPT. Parallel ports are generally found on legacy computer systems. Has 25 Pins

Duplexing Assembly - Laser Printers

The duplexing assembly turns a page that is already printed on one side so that it can be printed on the other side.

Feeder - Inkjet Printer Parts

The feeder may hold blank paper in a tray or cassette. Some inkjet printers are also copiers. - They may have an Automatic Document Feeder (ADF). - The ADF holds documents which are fed page by page onto the scanner bed for copying.

Feeder - 3D printer Parts

The feeder takes filament from a feed tube that is placed into the extruder. The feeder pulls it down to be heated and exits through the hotend nozzle.

2. Charging - How Laser Printing Works

The image on the drum is removed and the drum is conditioned for the new image. - A wire, grid, or roller receives a charge of approximately -600 volts DC uniformly across the surface of the drum. - The charged wire or grid is called the primary corona. - The roller is called a conditioning roller.

Test Printer Functions

The installation of any device is not complete until you have successfully tested all its functions. - Depending on the printer you have, functions might include: -- Print double-sided documents. -- Use different paper trays for different paper sizes. -- Change the settings of a color printer so that it prints in black and white or grayscale. -- Print in draft mode. -- Use an optical character recognition (OCR) application. -- Print a collated document. Note: Collated printing is ideal when you need to print several copies of a multiple page document. The Collate setting will print each set, in turn, as shown in the figure. Some printers will even staple each printed set.

How Laser Printing Works

The laser printing process involves seven steps to print information onto a single sheet of paper.

4. Developing - How Laser Printing Works

The toner is applied to the image on the drum. A control blade holds the toner at a microscopic distance from the drum. - The toner then moves from the control blade to the more positively charged image on the drum.

6. Fusing - How Laser Printing Works

The toner is permanently fused to the paper. - The printing paper is rolled between a heated roller and a pressure roller. - As the paper moves through the rollers, the loose toner is melted and fused with the fibers in the paper. - The paper is then moved to the output tray as a printed page. Laser printers with duplex assemblies can print on both sides of a sheet of paper.

5. Transferring - How Laser Printing Works

The toner, attached to the image, is transferred to the paper. - The corona wire places a positive charge on the paper. - Because the drum was charged negatively, the toner on the drum is now attracted to the paper. - The image is now on the paper and is held in place by the positive charge. - Because color printers have three cartridges of toner, a colored image must go through multiple transfers to be complete. - To ensure precise images, some color printers write multiple times onto a transfer belt that transfers the complete image to paper.

Transfer Roller - Laser Printers

The transfer roller assists in transferring the toner from the imaging drum to the paper.

Printer Sharing Privacy and Security Issues

There are potential data privacy and security issues when sharing printers: - Hard drive caching - Cached print files pose a privacy and security risk because someone with access to the device could recover this files and have access to confidential or personal information. - User authentication - To prevent unauthorized use of a network or cloud-based printer, permissions and user authentication methods can be used to control access to the printer. - Data privacy - Print jobs sent over a network could be intercepted and read, copied, or modified.

Network Scanning

There are three popular places to direct these scans: - Scan to cloud - The scan is uploaded to a storage location in the cloud such as Google Drive or Apple iCloud. - Scan to folder - The scan is sent to a network folder on the LAN. The scanning prompts should ask for the path to the folder to which you wish the scan to be saved. -Scan to email -The scan will be created as a file attachment in an email. The scanning prompts will ask for the hostname or IP address of the SMTP server and, often, the email account credentials.

Print Bed - 3D Printer Parts

This is the platform onto which the heated filament will form the object.

3. Exposing - How Laser Printing Works

To write the image, the photosensitive drum is exposed with the laser beam. Every portion of the drum that is scanned with the light has the surface charge reduced to about -100 volts DC. This electrical charge has a lower negative charge than the rest of the drum. As the drum turns, an invisible image is created on the drum.

3D Printer Characteristics

Traditionally, machines cut or drilled pieces out of raw material (e.g., stone, metal, wood) to create an object. -- This is known as subtractive manufacturing. -3D printers add the material used to create objects in layers or even small bits; therefore, they are known as additive manufacturing machines.

Printer Connection Types

Typically, printers connect to home computers using a USB or wireless interface. - However, printers may also connect directly to a network using a network cable or a wireless interface. - Serial

USB

USB is a common interface for printers and other devices. When a USB device is added to a computer system that supports plug-and-play, the device is automatically detected and starts the driver installation process.

Configuring Printer Sharing

Users who cannot connect to the shared printer might not have the required drivers installed. - They might also be using different operating systems than the computer that is hosting the shared printer. Windows can automatically download the correct drivers to these users. - Click the Additional Drivers button to select operating systems that the other users are using. - When you close that dialog box by clicking OK, Windows will ask to obtain those additional drivers. - If the other users are also using the same Windows OS, you do not need to click the Additional Drivers button.

7. Cleaning - How Laser Printing Works

When an image has been deposited on the paper and the drum has separated from the paper, the remaining toner must be removed from the drum. A printer might have a blade that scrapes the excess toner. Some printers use an AC voltage on a wire that removes the charge from the drum surface and allows the excess toner to fall away from the drum. The excess toner is stored in a used toner container that is either emptied or discarded.

Hotend Nozzle - 3D printer Parts

When the filament is heated to the correct temperature, it is extruded from this nozzle.

Wireless Printer Connections

Wireless printers enable hosts to connect and print wirelessly using Bluetooth or a Wi-Fi connection. - Wireless Bluetooth printers also allow for printing from mobile devices. - Wireless printers that use Wi-Fi connect directly to a wireless router or access point. - Setup is completed by connecting the printer to the computer with the supplied software or using the printer display panel to connect to the wireless router. - The printer's wireless adapter will support an 802.11 standard. -- The devices connecting to the printer must also support the same standard. - In wireless infrastructure mode, the printer is configured to connect to an access point. - Client connections to the printer go through the access point. - In wireless ad-hoc mode, client devices connect directly to the printer. -- NOTE: Ad-hoc mode is a mode of connecting wireless devices to one another without the use of a central device like a router.

Software Optimization

With printers, most optimization is completed through the software that comes with the drivers. - The following tools optimize performance: -- Print spool settings - Cancel or pause current print jobs in the printer queue. -- Color calibration - Adjust settings to match the colors on the screen to the colors on the printed sheet. -- Paper orientation - Select landscape or portrait image layout. - Printers are calibrated using the printer driver software. - Calibration makes sure that the print heads are aligned and that they can print on different kinds of media, such as cardstock, photographic paper, and optical discs. - Some inkjet print heads are fitted to the ink cartridge, so you might have to recalibrate the printer each time you change a cartridge.