Blackboard without powder

Abstract

The invention provides a blackboard without powders. The blackboard comprises a pressure sensing switch (1), a powder eruption device (2), an air circulation system (3), and a thin board (4) which is hollow inside. A blackboard pen touches a pressure sensor on the surface of the blackboard. When the sensor receives a signal and generates static electricity on a handwriting position on the inner surface of a front board of the blackboard, the signal is transmitted to the powder eruption device (2) which is inlaid on a corresponding position on the rear board of the blackboard. After the powder eruption device (2) receives the signal, the powder eruption device (2) sprays powders, and the powders are absorbed on the inner surface of the front board because of static electricity, and part of unabsorbed powders fall in a groove under the blackboard and wait to be recycled after use ends. When the pressure sensor on the front surface of the blackboard senses pressure for the second time, a power switch on a corresponding position is turned off, and the static electricity disappears, the attached powders fall off, so as to ensure convenience of modification. After one time use, the power supply on the surface of the blackboard is turned off, and the powders fall in the groove on the lower part of the back board.

Description

technical field [0001] The invention relates to a blackboard, in particular to a powder-free blackboard. Background technique [0002] With the progress of the times, people pay more and more attention to education, and blackboards play an indispensable role in campus teaching. Traditional blackboards will cause a lot of dust when they are erased and corrected. Teachers who have been working on the podium for many years often inevitably inhale the chalk dust raised, which poses a hidden danger to their health. Although dust-free chalk has been released one after another, its effect is still not very good. Although there are inventions such as projectors and touch screens, projectors cannot meet the requirements of some teachers for blackboard writing. Although touch screens are a good alternative to modern blackboards, they are expensive compared to traditional blackboards. The price makes it not very popular. [0003] Most of the dust-free blackboards now use water spray...

AI Technical Summary

Problems solved by technology

Although there are inventions such as projectors and touch screens, projectors cannot meet the requirements of some teachers for blackboard writing. Although touch screens are a good alternative to modern blackboards, they are expensive compared to traditional blackboards. The price makes it not well popularized

[0003] Most of the dust-free blackboards now use water spray instead of wiping the blackboard with chalk. Although this reduces the rise of chalk dust to a limited extent, the surface of the blackboard after being wet will affect the writing effect of the chalk. The evaporation of water on the surface will waste valuable classroom time and affect the teaching progress

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