[Advanced Intellectual Property]: Erhu is a traditional musical instrument, and the musical instrument itself belongs to the existing technology, so there is no patent dispute. However, the improvement technology of the existing erhu still exists.

For example, an applicant in Canada obtained the corresponding patent right, mainly by changing the direction of the sound window at the drum end of the erhu, so that the pronunciation of the erhu can be reflected upwards (or in other directions), thereby improving the sound quality of the erhu sound, increasing the volume of the erhu, and enabling the erhu player to hear his performance more clearly. At the same time, in the actual performance of the concert hall, the sound window reflecting upwards or in other directions directly sends the sound to the reflecting plate or reflector in other directions on the stage of the concert hall and passes through the top of the stage.