For quite some time, most mobile phones incorporate video outputs in high definition. This output is HDMI and may occur in 3 or more different variants. The HDMI can be normal and that is too large for a phone. Size Micro HDMI that connects to the phone and the other end has HDMI standard to connect to the projector. Or via USB with MHL adapter or with its own adapter. It does connect to your phone, because what interests us is that all end in HDMI.
If we have a projector in HD, that is, with a minimum resolution of 1280 × 720, you can connect your phone via cable type that leads to HDMI and already have a portable player that is our phone and a screen with our projector, since we can project that any wall.
In theory it should leave the screen of your phone first. If not, you may you may have to enter the display settings and activate the video output.
With this done, we can see movies, photos or whatever we want.