Types of interactive whiteboard (What are the types of interactive electronic whiteboards classified by principle)
Jan 24, 2025
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Introduction
As an advanced educational auxiliary human-computer interaction device, interactive electronic whiteboard has been widely used around the world. It not only changes the teaching method of traditional blackboards, but also provides multiple functions such as dust-free writing, free writing, and remote communication. Interactive electronic whiteboards achieve seamless connection with computers, projectors and other devices by combining large-screen projection technology, precise positioning test technology, etc. This article will discuss in detail the types of interactive electronic whiteboards classified by principle, covering their working principles, basic structures and their respective characteristics.
Basic principles and classification of interactive electronic whiteboards
Interactive electronic whiteboards can be divided into many types according to their working principles, mainly including electromagnetic induction, infrared induction, resistive pressure sensing, ultrasonic induction and CCD optical scanning. Each type has its own unique working principle and application scenario.
1. Electromagnetic induction electronic whiteboard
The working principle of electromagnetic induction electronic whiteboard is to use the propagation characteristics of electromagnetic waves in the air or in insulating objects. This electronic whiteboard consists of a receiving coil film arranged in two directions horizontally and vertically, and the size of the film is the same as the display area. The positioning principle is to use a pen that emits electromagnetic waves to emit electromagnetic waves in an intermittent manner. When the pen is close to the receiving coil film, the electromagnetic waves emitted by the pen will be sensed on the coil. The higher the electromotive force induced by the coil group closest to the pen, the X and Y coordinates of the pen can be obtained by calculation.
The characteristics of electromagnetic induction electronic whiteboards are relatively accurate positioning and pressure sensation during writing, that is, the thickness of the handwriting will be different depending on the weight of the writing. In addition, the uniformity of the display area is good, and the board surface is made of hard wood, with a lifespan of more than 10 years. However, electromagnetic induction electronic whiteboards must be written with a special pen, cannot be touched, and have a relatively slow response speed.
2. Infrared induction electronic whiteboard
The working principle of infrared induction electronic whiteboards is to cover the touch screen with infrared receiving tubes and infrared transmitting tubes. These infrared tubes are arranged in a one-to-one corresponding position relationship on the surface of the touch screen to form an infrared light network. When an object enters the infrared light network and blocks the infrared transmission and reception at a certain point, the intensity of the infrared received by the receiving infrared tubes in the horizontal and vertical directions of this point will change. The device can know where the touch is made by understanding the changes in the infrared reception.
Infrared sensing electronic whiteboards do not require special pens, and can be written or touched with fingers, pointers, etc., without fear of scratches. Even if there are any scratches in the board, it will not affect the operation. In addition, it has a long service life, fast response speed, and low cost. However, infrared sensing electronic whiteboards may be affected by strong infrared light, are more affected by the environment, and have no pressure response.
3. Resistive pressure-sensitive electronic whiteboards
The working principle of resistive pressure-sensitive electronic whiteboards is to achieve positioning through the pressure change of the resistor film. The basic structure of the electronic whiteboard is composed of multiple layers of film, including horizontal line resistor film, insulating grid, conductive film, insulating grid, vertical resistor film, etc. A fixed voltage is applied to the resistor film. In the absence of external force, the conductive film does not contact the resistor film, no voltage is measured, and no positioning information is reflected. When a hard object is pressed on a certain point of the resistive film, the current is read by the test circuit through the conductive film. This voltage is related to the position of the touch point. According to the voltage read from the horizontal and vertical directions, it can be converted into the X and Y direction positions of the touch point.
The resistive pressure-sensitive electronic whiteboard has relatively accurate positioning, does not require a special pen, and can be operated by touch. However, writing is more laborious, and the handwriting cannot be displayed if the force is not enough; the board surface is relatively soft and easy to scratch. Once scratched, it cannot be used; the reaction speed is slow, and it cannot be used for a large area.
4. Ultrasonic induction electronic whiteboard
The working principle of the ultrasonic induction electronic whiteboard is to locate through the reflection and reception of ultrasonic waves. Ultrasonic transmitters and receivers are placed around the electronic whiteboard. The transmitter emits ultrasonic waves. The ultrasonic waves are reflected back after encountering an object. The receiver receives the reflected ultrasonic waves and determines the position of the object by calculating the propagation time of the ultrasonic waves. Ultrasonic induction electronic whiteboards have the characteristics of accurate positioning and high precision. However, the market share of ultrasonic induction electronic whiteboards is relatively low, and its technical principles and application scenarios are relatively limited.
5. CCD light scanning electronic whiteboard
The working principle of CCD light scanning electronic whiteboard is to use CCD (charge coupled device) for light scanning and positioning. Two CCD linear array detectors and infrared emitters with fixed distances are set on one side of the display area, and reflective films that can reflect light are set on the other three sides. The CCDs distributed in the two corners detect the corresponding areas of the blocked area and reflect the linear array CCD respectively, and calculate the position of the object in the display area. The production process of CCD light scanning electronic whiteboard is relatively simple, with good stability and accurate positioning. However, it also has no pressure response, and its technical principles and application scenarios are relatively limited.
The basic structure and function of interactive electronic whiteboard
The basic structure of interactive electronic whiteboard includes core components such as electronic induction whiteboard, induction pen, computer and projector. The electronic induction whiteboard is a large induction screen with normal blackboard size and working under the support of computer hardware and software. Its function is equivalent to computer display and replaces the traditional blackboard. The induction pen has the dual functions of electronic whiteboard writing pen and computer mouse, and its function replaces the traditional chalk.
The interactive electronic whiteboard has very powerful functions. In addition to the projection function of a general computer screen, it also includes direct blackboard writing, electronic notes, and mouse replacement.
Direct blackboard writing
Using an electronic induction pen, you can write directly on the electronic whiteboard, just like writing on the blackboard with chalk. If necessary, you can also save the blackboard content at any time, which is convenient for teachers to organize, package and recycle after class. At the same time, calling different colors on the electronic whiteboard for blackboard writing can enhance the teaching process and teaching effect.
Electronic notes
The electronic whiteboard has a note function. During the teacher's teaching process, you can annotate the electronic documents, software interfaces, multimedia courseware, teaching pictures, etc. All of these (including blackboard writing) form electronic documents, and the teaching process can be clearly shown through playback. Teachers can also dynamically process the content of the specified area, highlight or enlarge the content of the area, and emphasize the teaching focus.
Replace the mouse
The tip of the electronic pen is equivalent to the left button of the mouse, and the pen body button is equivalent to the right button of the mouse. The electronic pen can be used to perform mouse functions such as single-click, double-click, select, drag, and right-click, just like using a mouse to operate a computer.