This is done with a laser poin

The present invention, s p o t - I d entifizierungstechnologie laser beam and mehrbenutzerprojektor wireless control technology, especially in technical areas, wireless control laser user identification and pen and recognition system, and refers to multiple users can be used. Projectors and computers are now used in many conferences, economic experiments, multimedia education, military decision-making and so on. In these applications, the traditional computer-controlled keyboard and mouse can no longer meet human needs. Thinking is necessary because thinking is used for personal thinking. Users must work in front of a computer while using the devices. Like all known inventions and designs, these designs were designed for the use of the same person. With the popularization of computer communication technology, multi-loop switching technology has been developed rapidly. Interdependent control system means that different users can use their own conversion control devices to control the computer simultaneously in the same space without conflicting with each other. For example, many participants want to attend a game conference for several days. They use a Laser pointer on the one hand and a large projector on the other. During this period, the laser must be distinguished, so that the operations of each user do not affect the operations of other users.

https://www.htpow.com/ultra-powerful-laser-pointer-blue-10000mw-class-iv-445nm-p-1028.html

This screen connects to the desktop via a VGA port and shows the level of spending on the computer. The camera is connected to a computer through a USB port, and the computer receives real-time images from the camera device. The photograph is a grayscale image made from a two-dimensional model. 255 Fixed position of the camera in the room. The Angle of the camera covers the whole picture, and the pixels of the real-time image of the camera correspond to each pixel on the picture.

https://www.htpow.com/high-powered-30000mw-blue-laserpointer-445nm-worlds-brightest-p-1027.html