To clearly understand how interactive whiteboards can enhance the teaching environment, you need to understand the sensing technologies used to track the interaction on the screen surface. These are resistive, laser, infrared, camera-based and ultra sonic optics. Of all these technologies, the most successful in commercial interactive whiteboards use electromagnetic and resistive technology.
Resistive touch screens consist of two flexible sheets each with a layer of resistive material and separated by a layer of micro-air space. In operation, the two screens squeeze together, recording the exact location where the screen was touched. With this technology, one can use a finger, a stylus or any other pointing device. Thanks to electromagnetic technology, the card has a network of wires embedded under the surface of the card. These interact with the tip of the stylus to give the exact location using the X and Y coordinates.
The type of stylus varies. You can use an active pen that uses the battery or that is hardwired to the whiteboard. There are also passive styli that rely on electrical signals produced by the whiteboard, so no external power source is needed. Simply put, the electromagnetic whiteboard can be described as having magnetic sensors that react and send messages to the computer when the board is activated using a magnetic pen.
Besides the two major technologies, other technologies are also gaining momentum in the interactive whiteboard market and therefore should not be ignored. With optical infrared technology, you have to press on the surface of the card so that the infrared light is visible. This allows the assistive software to triangulate the location of the stylus or marker. With this technology, the whiteboard can be made from any material.
Laser interactive whiteboard technology uses an infrared laser located in the top corners of the whiteboard. Laser beams work by scanning the surface of the whiteboard using rotating mirrors. The marker or stylus used to write on the board reflects the laser beams back to the source thus allowing triangulation of the X and Y coordinates. This technology works well with a hard surface such as steel or ceramic which also has the advantage easy to clean.
Along with ultrasound and infrared, the stylus emits ultrasonic sound as well as infrared light when pressed to the surface of the card. The board has two ultrasonic microphones that receive sound and calculate the time of arrival differences. This helps in the triangulation of the X and Y coordinates. This technology also allows the whiteboard to be made from any material. However, a suitable suitable stylus or an active dry erase marker is required.
Besides these technologies, there are also other less important technologies such as frustrated internal reflection, ultrasound only, and the IWB Wii Remote. Although interactive whiteboards are technologically advanced, there are some issues that are common to most types. For example, using permanent markers on whiteboards can cause problems. Another common problem is the risk of dents, punctures and other damage to the surface that is not encountered with normal boards.
Source by Thomas Radcliff