Graphic Communication. Input, Output & Storage

Transcription

1 Graphic Communication Input, Output & Storage

2 Terms Within the field of computer aided design (CAD) and computer aided graphics (CAG) there are three types of device that are used. Input devices These are devices that are used to put in commands to a computer or a piece of software by the user. Output devices These are pieces of hardware or software that display and show information to the user. Storage devices These are pieces of equipment that store work, files and information electronically to be used by the user. It is important that you have a good understanding of what group certain pieces of equipment is categorized in.

3 Input Devices As mentioned previously, Input devices are pieces of hardware, software and equipment that are used to enter commands or information into a computer by the user. QWERTY Keyboard. The most commonly used input device. Computer keyboards have the function to enter letters and numbers on to the screen and can send commands to the computer. Each key has a switch which sends a particular code to the computer Mouse. The mouse is used to guide the pointer around the screen on a computer. Functions are selected by clicking one of the two buttons on the mouse. The mouse detects movement optically (beam of light) or by a ball moving against sensors inside the mouse. The mouse is the most commonly used device for Graphics work. Trackerball. This is very similar in operation to a mouse. The difference is that the actual body of the device does not move around, but fingers are placed on the large ball and used to move the pointer around this way. This device requires very little desk space and no mouse mat. Graphics Tablet. This is quick to use and can provide pinpoint accuracy. It is used as an electronic way to transfer sketches and drawings directly into a computer device. The user uses a stylus, similar to a pen, and draws directly on to the tablet just as they would on paper.

4 Input Devices Continued Joystick. Computer joysticks are very similar in shape and function to aircraft control joysticks. They are most commonly used for computer gaming on PC s and provide the user with a very realistic feel of control. This device is rarely used for computer aided graphics work. Digital Camera. This device takes still photographs in a digital form. These images can then be transferred or downloaded on to a computer, where they can be manipulated and altered using an image editing program. These cameras do not use or require film and can take and store hundreds of images on an internal memory card which can be viewed on the device at any time. Some digital cameras have a secondary function to record videos as well as images. Flatbed Scanner. A flatbed scanner electronically converts paper based images and information into a computer file. Photographs, information, text and drawings can be scanned in full colour. This process is known as digitising.

5 Output Devices Output devices are pieces of equipment which display information and allow the user to visualise and complete work on a computer device. Monitor. The monitor is perhaps the most vital part of a common computer system. It acts as the interface between the user and the computer device, as it displays the processes that the computer is doing to the user. It can be used to view videos or images, write out text or complete graphical work. Flatbed Plotter. A flatbed plotter has a mechanical arm which can move in four directions, left to right, forward and backward over a fixed sheet of stationary paper. This arm has a nib which acts as a pen or pencil to transfer an image from the computer on to the paper, much like a printer. Flatbed plotters tend to be quite large and bulky pieces of equipment. Drum Plotter. Drum plotters are more like printers than flatbed plotters are. The paper moves through the drum where a nib or pen like instrument plots the image on to the paper. Drum plotters are restricted to line art. Ink-Jet Printer. An inkjet printer is a type of computer printer that creates a digital image by propelling variable-sized 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.

6 Storage Devices Storage devices are instruments which store electronic files, ranging from text, images, video and information. These files can then be easily transferred and accessed by the user at any computer device. USB Flash Drive. A small storage device which can store electronic files. This device is usually very small and can plug directly into a USB port, making it very handy. These devices are often limited to a much smaller capacity than hard drives. CD. CD s can be read by almost every common computer device. They require a special type of drive in a computer to have information put on to them, which is often time consuming also. They have a fairly small storage capacity. DVD. DVD s work in the same way as CD s and also require a special type of driver in a computer to put information and files on to them. This storage device is normally associated with video files. DVD s usually have a slightly larger capacity than CD s. Internal and External Hard Drives. A hard drive provides the memory for computers and laptops and cannot be removed. This is known as an internal hard drive. There are also external hard drives which work in the same manner as a USB flash drive except they have a much larger capacity. Portable hard drives can reach up to 1TB of file capacity!

7 Storage Devices Continued As with any device or piece of software, there are advantages and disadvantages found with the storage devices that were mentioned. Advantages: Storing files electronically rather than on paper saves a lot of space within an office environment. It also cuts out a lot of the paper usage which can save money. The files are easily transferred from computer to computer. This can be done by over the internet. Also most of the common storage devices fit easily into a bag or even a pocket. It is a lot easier to edit electronic files, simply by opening them up, changing what is needed then saving. Rather than having to re-write a paper copy. Files on these storage devices can be duplicated with ease. This saves the need to photocopy or re-write paper copies. Disadvantages: Buying these storage devices can be very expensive initially. Viruses and bugs can infect the storage device, which can ruin every file contained within it. Electronic files can be accidentally deleted or corrupted which again ruins the work of the user. Since some of the devices are quite small, they can be easily lost or stolen. The user would then lose all of their files if they did not have them backed up somewhere else. Not all storage devices have a large capacity, this means that a user may have to buy more than one to store all of their files.