Specialized Input Device Types
keyboards and mice are the most popular of the input devices for personal computers, there are some specialized input devices that you might encounter in your workplace.
1) Bar code reader : Bar codes provide a simple and inexpensive method of encoding text information that is easily read by inexpensive electronic readers. A bar code reader decodes a bar code by scanning a light source across the bar code and converting the pattern of reﬂected light to an electronic signal that is decoded back to the original data by electronic circuits. There are currently four different types of bar code readers available: pen-type readers (or bar code wands), laser scanners, Charge Coupled Device (CCD) readers, and camera-based readers. Bar code readers provide either keyboard wedge output or RS-232 output. The bar code readers with keyboard wedge output plug directly into the keyboard port on the PC, and they also provide a pigtail connector so that you can plug in a keyboard at the same time. An RS-232 or serial interface bar code reader is connected to an available serial port on the PC. A program called a software wedge is required to direct the data from the bar code reader to the application.
2) Touch screen : Touch screens enable users to enter input by touching areas on a monitor screen. Touch screens are composed of:
- Touch sensors. The sensors can be a panel that lays over a standard monitor or can be built into a special touch screen monitor where the user actually touches the glass on the monitor.
- A controller. If using an overlay panel, the controller connects to the panel and then to a PC port. Many use a COM or USB port, although there are special instances where the controller connects to a drive or other device or port. For touch screens with built-in touch sensors, the controller is built into the monitor. In this case, the monitor contains two cables—one to the monitor port and one to the COM or USB port (or other port).
- Device driver or specialized software. This enables the operating system to receive and interpret information from the touch screen device. Touch screens can gather input using technologies such as infrared, capacitive touch, resistive touch, or surface acoustic wave. They can be ﬁnger touch or stylus touch.
3) Stylus : A stylus is an input method commonly used with PDAs, tablet PCs, and other mobile computing devices. Styluses (or styli) are used either to select pre-deﬁned items on a touch screen, or to capture handwriting as the input information, such as signing a touch screen to authorize a credit card payment at a store. A stylus used for this purpose is usually a plastic inkless pen with a small, rounded tip, but other items with very small contact areas can be used, such as a pencap, a pencil eraser, or a ﬁngernail. The stylus itself has no electronics in it—it is simply used to press against a touch screen.
4) Interactive whiteboard : An interactive whiteboard looks similar to a traditional whiteboard; however, it connects to a computer using a wired USB cable, or connects wirelessly through a Bluetooth connection. A projector is typically used with it to display the computer’s desktop, and it can be used as an input device once the correct device drivers are installed on the computer. You can manipulate the computer directly on the whiteboard using a special stylus or by using your ﬁnger. Interactive boards are used in many schools today, and have become a very popular teaching tool.
—————— Thanks Everyone