Projection display apparatus

A projection display apparatus, comprising:

• an image light emitter that emits image light in a first polarization state of one of P-polarized light and S-polarized light;
• an optical path separation element including a polarization separation coating that transmits the image light in the first polarization state incident from the image light emitter, and reflects light in a second polarization state of the other of the P-polarized light and the S-polarized light;
• a projection lens unit that enlarges and projects the image light transmitted through the optical path separation element on a projection target, and incidents external light including the image light reflected on the projection target;
• a ¼ wave plate that is disposed between the optical path separation element and the projection lens unit, converts the image light in the first polarization state into circularly polarized image light, and converts the circularly polarized image light reflected by the projection target into image light in the second polarized state;
• an imaging element that images the external light incident via the projection lens unit and the optical path separation element;
• a polarizing plate that is disposed between the optical path separation element and the imaging element, and transmits the external light in the second polarization state;
• and
• a reflected light attenuator that is disposed on a side opposite to the imaging element with respect to the optical path separation element, and attenuates the image light reflected within the optical path separation element.