According to the inquiry of official website Zhihu, Hubert obtained the American invention patent 1903 for flashlight on August 26th, which is a portable lighting tool that assembles light bulb, battery and switch in a cylinder, and the first flashlight was born in the world, so 1920 led to the flashlight in the United States, and 1920 led to the Wen Zhen flashlight factory in Guangzhou.