In order to provide touch based interaction for surfaces without touch function, Apple has proposed a set of patent ideas based on projection. On Tuesday, the U.S. patent and Trademark Office granted the company a patent for a self mixing 2D / 3D user input detection and laser scanning system. For educational institutions, teachers can show more interactive content to students on the projection wall instead of using expensive and laborious large touch screen equipment. It is reported that the patent mainly focuses on the transmission and reflection of light, such as which part of the projection plane (or path) is blocked by objects. The so-called shelter can be the user’s finger or pointer. < / P > < p > for this purpose, the projector needs to emit the detection beam through the laser diode, such as the vertical cavity surface emitting laser (VCSEL) used by apple on the face ID sensor. < / P > < p > the patent mentions the “self mixing interferometric sensor” to collect this part of information, which is characterized by the ability to mix multiple light sources together to create interference patterns to measure distance and other data points, and then analyze their displacement changes. In addition, through interferometry, the system can determine the distance between the object and the projection surface, and then track the moving object interaction. For example, one finger is pointing at the picture (touch interaction), while the other hand is hanging in the air (non touch gesture). < / P > < p > finally, the inventors of this patent, Mehmet Mutlu and Ahmet Fatih Cihan, were initially submitted on May 9, 2019. As for when it can be used in actual products, it still needs time to test. [image] Google secretly tests 6GHz networks in 17 states of the United States