Screen, display module, mobile terminal and display device

The embodiment of the invention discloses a screen. The screen comprises a first optical plate, a reflecting piece and a second optical plate. The first optical plate is provided with a light-in face, a light-out face and a side face, wherein the light-in face and the light-out face are oppositely arranged, the side face is connected between the light-in face and the light-out face and is a slope, and the included angle between the side face and the light-in face is an obtuse angle. The reflecting piece is located between the second optical plate and the side face. The reflecting piece is attached to the surface of the side face to form a reflecting surface, and the reflecting surface is used for reflecting light shot in from the light-in face. According to the screen, the included angle between the side face and the light-in face is set to be the obtuse angle, and the reflecting piece is attached to the side face, so that the reflecting surface is formed on the side face; although the area of the light-in face is smaller than that of the light-out face, the light can be reflected out when the light on the light-in face is shot into the side face, in other words, the region, corresponding to the side face, of the light-out face is turned into a user visual region visually, and therefore the screen with the large visual region is provided.