Stereo projection screen and stereo projection system

A stereo projection system, comprising:

• a polarized projector, adapted to project a first image light beam having a first polarization state and a second image light beam having the first polarization state;
• a stereo projection screen, disposed on a transmission path of the first image light beam and the second image light beam, and having a first display area and a second display area, wherein the stereo projection screen comprises:
• a scattering screen, wherein a scattering structure layer is disposed on a side of the scattering screen facing the polarized projector;
• a phase retardation layer, disposed between the scattering screen and the polarized projector;
• and
• a metal reflection layer, covering at least a part of the scattering structure layer, and adapted to reflect the first image light beam from the phase retardation layer back to the phase retardation layer,
• wherein the first image light beam has a second polarization state after being transmitted to the first display area and leaving the stereo projection screen, the second image light beam still has the first polarization state after being transmitted to the second display area and leaving the stereo projection screen, and the second polarization state is orthogonal to the first polarization state;
• and
• a pair of polarizing glasses, having a left-eye lens and a right-eye lens, wherein one of the left-eye lens and the right-eye lens is adapted to allow the first image light beam having the second polarization state to pass through and absorb the second image light beam having the first polarization state, and the other of the left-eye lens and the right-eye lens is adapted to allow the second image light beam having the first polarization state to pass through and absorb the first image light beam having the second polarization state.