2001.
Background technology: There are currently many types of magnetic writing boards on the market. These magnetic writing boards use magnetic pens to write or draw on the writing board core. The magnetic powder is adsorbed to the upper surface of the writing board core, thereby displaying text or pictures on the upper surface of the writing board core. When it is necessary to remove the text or pictures on the upper surface of the writing board core, the degaussing mechanism is used under the writing board core. Just scratch the surface, so that the magnetic powder that was originally adsorbed to the upper surface of the writing board core can fall back to the lower surface of the writing board core, thereby achieving the purpose of erasing the words or pictures originally written with the magnetic pen. For example, the Chinese patent published on October 5, 2011, with the publication number CN201998666U, discloses a magnetic adsorption environmentally friendly writing board with a backing plate installed in the frame, and upper rollers and upper rollers installed at the upper and lower parts of the frame respectively. The lower drum is equipped with annular magnetic curtains on the upper drum and the lower drum. A driving device is installed on the lower drum and a storage tank is provided. The storage tank is filled with ferrotitanium particles. There are scrapers and brush strips; a constant force tensioning device is installed on the upper roller, and a control switch is provided on the surface of one side of the frame. The control switch is connected to a controller installed in the inner cavity of the frame. The controller is connected to the driving device through wires. , the upper limit switch and the lower limit switch are connected. The magnetic adsorption environmentally friendly writing board has a complex structure, inconvenient operation, and high production cost. For another example, the Chinese patent with publication number CNMM021, published on March 21, 2001, discloses a magnetically controlled writing board, which consists of a writing board, a board eraser, a fixed frame, and a magnetic writing pen. It consists of: the writing board is mounted on the base plate, and the upper and lower sides of the base plate are equipped with slideways. The wiper sliding arm is clamped by the slideways on the upper and lower wheel boxes, and is clamped on the lower slide of the baseboard. The board wiper is mounted on the U-shaped slide rod. , both ends of the U-shaped sliding rod are fixed on the upper and lower wheel boxes respectively, and there are control buttons on the panel. The hand-held part of the panel wiper in this magnetically controlled writing board is exposed outside the fixed frame, resulting in an unsightly appearance of the writing board, and the resetting of the panel wiper is inconvenient, making the use of the magnetically controlled writing board inconvenient. Although there are many types of existing magnetic writing boards, existing magnetic writing boards usually have the following shortcomings: 1. The shell of the writing board is usually an injection-molded plastic shell, and a mold is required for each style. Production costs are quite high. 2. The degaussing structure mainly includes a sliding rod with a magnetic strip. The hand-held part of the sliding rod is exposed outside the casing. When in use, the sliding rod slides from one side of the writing board to the other side, thereby achieving the purpose of degaussing the writing board. , on the one hand, the hand-held part of the slide bar is exposed to the outside of the casing, resulting in an unsightly appearance of the writing board. On the other hand, there is no reset device in the degaussing mechanism, making it inconvenient to reset the degaussing mechanism. In addition, it is difficult to slide the slide by hand. When sliding the rod, the force mainly acts on one end of the sliding rod. Since the sliding rod itself is long, the sliding rod will often get stuck when sliding, and the operation is not very flexible, thus greatly reducing the quality of the writing board. 3. The magnetic writing board is mainly used for writing or drawing, and its functions are not concentrated enough, which brings inconvenience to users and reduces its applicable scope. 4. The writing board core may leak oil during use, and there is no effective sealing structure between the writing board core and the plastic shell. Once the writing board core leaks oil, it will cause the magnetic writing board to leak. Oil, thus greatly affecting the use of magnetic writing boards, and leaked oil stains may cause harm to children. 5. The overall appearance is not beautiful, and the back of the magnetic writing board is uneven, which can easily cause harm to the human body. In addition, plastic products have a short service life and can easily break and injure children. Because there is currently no magnetic writing board with simple structure, reasonable design, reliable performance, simple operation, convenient use and low production cost.