Abstract: The invention discloses a mosaic structure of the electronic white board, including infra-red rectangular box and back board formed infrared matrix. The infra-red rectangular box is mainly composed of matching combination of infrared transmitter and infrared receiving unit connected and fixed to back board. The infrared transmitter includes several splicing of electrical infrared emission units, and the infrared emission units involve PCB and linear array of infrared emission heads. The infrared receiving unit includes several electrical splicing of infrared receiving modules. The infrared receiving module involves PCB and linear array of infrared receiving heads corresponding with emission heads. The electronic whiteboard rectangular box can be standardized in production, increasing efficiency and reduces costs. You can splice the corresponding size according to the projector requirements. It is convenient and practical.