Monday, October 25, 2010

Other output devices



The Printer

An external hardware device responsible for taking computer data and generating a hard copy of that data. Printers are one of the most used peripherals on computers and are commonly used to print text, images, and/or photos. The image to the right is a visual example of the Lexmark Z605 Inkjet printer and is an example of what a printer may look like.
Types of printers
·        Dot Matrix printer
·        Inkjet printer
·        Laser printer
·        Thermal printer
·        LED printer


The Projector

A hardware device that enables an image, such as a computer screen, to be projected onto a flat surface. These devices are commonly used in meetings and presentations as they allow for a large image to be shown so everyone in a room can see. To the right is a View Sonic projector and an example image of what a projector may look like. As can be seen in this image the projector is a small device often a little bigger than a toaster and typically weigh a few pounds.

Sound card

Also known as a sound board or an audio card, a sound card is an expansion card or integrated circuit that provides a computer with the ability to produce sound that can be heard by the user either over speakers and/or headphones. Below is an image of the Creative Sound Blaster X-Fi Extreme Audio sound card and an example of what a sound card may look like.
To the right is an example of what a generic sound card may look like from the back of your computer and the connector symbols usually found next to each of the connections. With almost every sound card you'll have four connections: sound out or line out, sound in or line in, Microphone, and MIDI (Joystick).
You may also find that these ports are color coded as seen in the above picture of a computer sound card. If you're using speakers or other audio peripherals that are also color coded you can easily identify what port to use by matching the colors.
Below is a listing of some of the functions of a computer sound card.
Games
Audio CDs
Watch movies
Audio conferencing
Creating and playing Midi
Educational software
Business presentations
Record dictations
Voice recognition

The Video adapter

Also known as a graphics card, video card, video board, or a video controller, a video adapter is an internal circuit board that allows a display device such as a monitor to display a picture from the computer. Today video cards are most commonly connected to the AGP, PCI, or PCIe expansion slot on the motherboard, however, can also be found on-board.
Above is an example image of the ATI Radeon 9600 AGP video card; most video cards today resemble this picture. As can be seen this video card has three connections on the back, the standard VGA connector, S-Video connector, and the DVI connector. In this example the card connects into the AGP slot on the computer motherboard.



CD/DVD/Floppy Disc:

CD, DVD and floppy disc are output devices that can also be used as storage and input devices. The computer sends data to the disc, where it is embedded and can be later retrieved.
Compact disc, or CD, is an optical device that stores audio and visual data in a digital format. Data is placed on the disc, using a laser writer that embeds the data into the disc's coating.

Digital Versatile Disc, or DVD, is an optical device that stores visual data in a media format. DVDs feature a dual coating system that allows audio and visual data to be written at the same time by using a laser.

Floppy disc is a magnetic storage device. A layer of magnetized material is placed within a proactive plastic casing. The computer embeds the data into the magnetized material, using a writing head.

♥List of Prices of Input and output devices♥








Tuesday, October 19, 2010

video about input and output devices

video

Other output devices



The Printer

An external hardware device responsible for taking computer data and generating a hard copy of that data. Printers are one of the most used peripherals on computers and are commonly used to print text, images, and/or photos. The image to the right is a visual example of the Lexmark Z605 Inkjet printer and is an example of what a printer may look like.
Types of printers
·        Dot Matrix printer
·        Inkjet printer
·        Laser printer
·        Thermal printer
·        LED printer


The Projector

A hardware device that enables an image, such as a computer screen, to be projected onto a flat surface. These devices are commonly used in meetings and presentations as they allow for a large image to be shown so everyone in a room can see. To the right is a View Sonic projector and an example image of what a projector may look like. As can be seen in this image the projector is a small device often a little bigger than a toaster and typically weigh a few pounds.

Sound card

Also known as a sound board or an audio card, a sound card is an expansion card or integrated circuit that provides a computer with the ability to produce sound that can be heard by the user either over speakers and/or headphones. Below is an image of the Creative Sound Blaster X-Fi Extreme Audio sound card and an example of what a sound card may look like.
To the right is an example of what a generic sound card may look like from the back of your computer and the connector symbols usually found next to each of the connections. With almost every sound card you'll have four connections: sound out or line out, sound in or line in, Microphone, and MIDI (Joystick).
You may also find that these ports are color coded as seen in the above picture of a computer sound card. If you're using speakers or other audio peripherals that are also color coded you can easily identify what port to use by matching the colors.
Below is a listing of some of the functions of a computer sound card.


Games

Audio CDs

Watch movies
Audio conferencing
Creating and playing Midi
Educational software
Business presentations
Record dictations
Voice recognition

The Video adapter

Also known as a graphics card, video card, video board, or a video controller, a video adapter is an internal circuit board that allows a display device such as a monitor to display a picture from the computer. Today video cards are most commonly connected to the AGP, PCI, or PCIe expansion slot on the motherboard, however, can also be found on-board.
Above is an example image of the ATI Radeon 9600 AGP video card; most video cards today resemble this picture. As can be seen this video card has three connections on the back, the standard VGA connector, S-Video connector, and the DVI connector. In this example the card connects into the AGP slot on the computer motherboard.



CD/DVD/Floppy Disc:

CD, DVD and floppy disc are output devices that can also be used as storage and input devices. The computer sends data to the disc, where it is embedded and can be later retrieved.
Compact disc, or CD, is an optical device that stores audio and visual data in a digital format. Data is placed on the disc, using a laser writer that embeds the data into the disc's coating.

Digital Versatile Disc, or DVD, is an optical device that stores visual data in a media format. DVDs feature a dual coating system that allows audio and visual data to be written at the same time by using a laser.




Floppy disc is a magnetic storage device. A layer of magnetized material is placed within a proactive plastic casing. The computer embeds the data into the magnetized material, using a writing head.

Monday, October 18, 2010

Some Output Devices

Computer speakers
Computer speakers, or multimedia speakers, are speakers external to a computer that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.175mm (1/8 inch) stereo jack plug often colour-coded lime green (following the PC 99 standard) for computer sound cards. A plug and socket for a two-wire (signal and ground) coaxial cable that is widely used to connect analog audio and video components. Also called a "phone connector," rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8" thick by 5/16" long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 500 milliamps provided by the USB port, allowing about 2.5 watts of output power.
Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small plastic boxes with mediocre sound quality. Some of the slightly better computer speakers have equalization features such as bass and treble controls, improving their sound quality somewhat.
The internal amplifiers require an external power source, known as a 'wall-wart'. More sophisticated computer speakers can have a 'subwoofer' unit, to enhance bass output, and these units usually include the power amplifiers both for the bass speaker, and the small 'satellite' speakers.
Some computer displays have rather basic speakers built-in. Laptops come with integrated speakers. Unfortunately the tight restriction on space inevitable in laptops means these speakers unavoidably produce low-quality sound.
For some users, a lead connecting computer sound output to an existing stereo system is practical. This normally yields much better results than small low-cost computer speakers. Computer speakers can also serve as an economy amplifier for MP3 player use for those who wish to not use headphones although some models of computer speakers have headphone jacks of their own.








The headphones:

Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of connecting them to a signal source such as an audio amplifier, radio or CD player. They are also known as stereo phones, headsets or, colloquially cans. The in-ear versions are known as earphones or ear buds. In the context of telecommunication, the term headset is used to describe a combination of headphone and microphone used for two-way communication, for example with a telephone.


The headphones







The monitor

Also called a video display terminal (VDT) a monitor is a video display screen and the hard shell that holds it. In its most common usage, monitor refers only to devices that contain no electronic equipment other than what is essentially needed to display and adjust the characteristics of an image.
Like most TVs, the computer monitor has a CRT (Cathode Ray Tube) that is found inside the computer monitor as illustrated in the picture to the right. The CRT is the main component and most expensive part within your computer monitor.

The monitor






Output Devices

video

This is a video about Output Devices 

♥Output devices♥




Output devices



Any device that outputs information from a computer is called, not surprisingly, an output device. Since most information from a computer is output in either a visual or auditory format, the most common output devices are the monitor and speakers. These two devices provide instant feedback to the user's input, such as displaying characters as they are typed or playing a song selected from a playlist.

While monitors and speakers are the most common output devices, there are many others. Some examples include headphones, printers, projectors, lighting control systems, audio recording devices, and robotic machines. A computer without an output device connected to it is pretty useless, since the output is what we interact with. Anyone who has ever had a monitor or printer stop working knows just how true this is. Of course, it is also important to be able to send information to the computer, which requires an
input device.


Tuesday, October 12, 2010

Input devices

Input devices 



The keyboard
A 'keyboard' is a human interface device which is represented as a layout of buttons. Each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or even projected keyboards.
Keyboards usually have the following:
  • Keys for the letters of the alphabet.
  • Keys for punctuation symbols.
  • Numbered keys or a numeric keypad (or both).
  •  Keys to move the typing cursor and other text controls, such as Tab, Insert, Delete, Backspace, Enter, and so on.
  • Keys which change the function of other keys, such as Shift, Caps Lock, Alt, and Ctrl.
  • Function keys numbered from F1 to F12. The function of these keys is set by whichever program is running.
                                                      

The Keyboard.

The pointing device
A pointing device is any human interface device that allows a user to input spatial data to a computer. In the case of mice and touch screens, this is usually achieved by detecting movement across a physical surface. Analog devices, such as 3D mice, joysticks, or pointing sticks, function by reporting their angle of deflection. Movements of the pointing device are echoed on the screen by movements of the cursor, creating a simple, intuitive way to navigate a computer's GUI.
  • A mouse is used by moving it across a mouse mat or other flat surface. This moves a ball on the bottom of the mouse. The movement of the ball sends a signal to the computer. Software interprets this signal and performs an operation, such as moving a cursor or drawing a line.
  • A mouse has two or more buttons on top of it, the function of which depend upon the software being used.


A computer mouse


The scanner

A scanner is a device that uses light to read an image or text and turn it into a digital message. This media can then be used to store, change and send the image or text. There are various types of scanners. The three most common are Drum, flatbed and hand. Drum scanners use photomultiplier tubes (PMT). Flatbed scanners use a glass pane and a bright light. Hand scanners are dragged across the image manually.

  • Hand-held scanners are dragged across the paper to scan it.
  • Flatbed scanners have the paper placed on top of them, in a similar way to a photocopier. These are more expensive than hand-held scanners but they are usually able to produce higher resolution images.
  • Companies needing to store paper records can transfer them to microfilm. A microfilm is a series of page images, miniaturised onto 35mm film. Special scanners are available to prepare and read microfilm using a computer.
  • If a scanner is used to scan a page of text, Optical Character Recognition (OCR) software can be used to convert the scanned image into text data that can be edited using word processing software.
                                               



The scanner




The trackball:

A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor. Large tracker balls are common on CAD workstations for easy precision. Before the advent of the touchpad, small trackballs were common on portable computers, where there may be no desk space on which to run a mouse. Some small thumb balls clip onto the side of the keyboard and have integral buttons with the same function as mouse buttons. The trackball was invented by Tom Cranston and Fred Long staff as part of the Royal Canadian Navy's DATAR system in 1952, eleven years before the mouse was invented. This first trackball used a Canadian five-pin bowling ball.
  • A trackball can be used as an alternative to a mouse. It has buttons, like a mouse, but the pointer is moved using a rotating ball set into the top of the device (basically an upside-down mouse).
  • Some people find a trackball easier to use than a mouse. One advantage is that it does not need a flat area to use it. For this reason, trackballs are sometimes included on laptop computers.

                                           





The TrackBall



The touchpad

A touchpad (also track pad) is a pointing device consisting of specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. They are a common feature of laptop computers and also used as a substitute for a computer mouse where desk space is scarce. Touchpad vary in size but are rarely made larger than 40 square centimeters (6.3 x 6.3 cm or about 6 inch²). They can also be found on personal digital assistants (PDAs) and some portable media players, such as the iPod using the click wheel.


  • A touch pad is another device for moving the pointer. In this case, you use your finger or a pen-like instrument (or stylus) on a sensitive pad to move the screen pointer.
  • Because a touch pad is flat and does not require the user to push down a specific key (as with a keyboard) or grasp it (as with a mouse), it is often used as an input device for people with particular disabilities. Touch pads are also used on laptops and palmtop computers.
  • Another form of touch pad is the graphics tablet. This enables the user to create an image on the computer by drawing on the pad with a specially designed pen. Graphics tablets are used by graphic design artists and for children's drawing software.



The touchpad



The joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick.
  • A joystick consists of a base and a stick perpendicular to the base. The stick can be moved in any direction, enabling the user to move an object around the computer screen. A joystick can perform a similar function to a mouse or trackball, but is only commonly used for playing games.



The joystick


The microphone
The microphone converts audio signals to electrical waves and these can be converted by electronic circuitry in the computer to digital from. What is difficult is the recognition by the computer, of the signal, so that it can be handle it in the same way as if it had been typed. Highly sophisticated speech-recognition software is required to be able to match the sound uttered by the user with a vocabulary of sound signals stored in the computer and to display the words on the screen as though they had been entered at the keyboard.

The microphone

The Digital Camera

Digital cameras take pictures in electronic format, providing convenience for users who want to preview, modify and delete photos immediately. A digital camera hooks up to your computer as an input device--typically via a USB cable. Drivers and digital camera software applications installed on your computer make it possible to transfer the digital photos to your system.

  • Digital cameras work in much the same way as normal cameras, except that the exposure from the subject is recorded onto light sensitive diodes not photographic film. The image is saved to a flash memory card (CompactFlash for example). Images can often be printed directly to a printer or displayed on a television or can be transferred to a computer (either by connecting the camera to a suitable port (such as a USB port) or by inserting the memory card into a card reader.
  • There are also devices to capture moving images. Web Cams can record low resolution video images. High resolution digital video cameras are available, but are still quite expensive. Some filmmakers are starting to record motion pictures entirely on digital video.

The Digital Camera


The Webcam

A web camera, or webcam, is an input imaging device that typically connects to a USB port on a computer. The device inputs live picture and image feeds, which can be connected to the Internet in real-time. Webcams have many uses, including connecting people to video conferences and displaying live weather and traffic conditions over the Internet.
                                                               






Light pen
  • A light pen is a hand-held device (very similar to a standard ballpoint pen) that has a device at the tip, which either emits light or is light sensitive. The user is able to send information to the computer by touching the pen onto certain areas of a specially designed screen.
  • Light pens are not widely used because they require a lot of arm movement, making them tiring and uncomfortable to use.
  • Possible uses include engineering production lines and science laboratories where dirt or other environmental factors make the use of a keyboard or mouse impractical.

 

Light pen