Projection display apapratus

A projection display apparatus comprising:

• a light source;
• a wavelength conversion element configured to convert a wavelength of light from the light source;
• a driver configured to rotate the wavelength conversion element;
• an image generator configured to generate an image by using light from the light source and light wavelength-converted by the wavelength conversion element;
• and
• a controller configured to control the light source, the driver, and the image generator,
• wherein the controller is configured to:
• in a first mode to project an image with the light source turned on, rotate the wavelength conversion element at the first number of rotations per unit time,
• in a second mode to supply the light source with power which is smaller than that supplied to the light source in the first mode, rotate the wavelength conversion element with the second number of rotations per unit timewhich is smaller than the first number of rotations per unit time, and
• in a third mode to supply the light source with power which is smaller than that supplied to the light source in the first mode and to supply the image generator with power that is smaller than that supplied to the image generator in the first mode, rotate the wavelength conversion element with the third number of rotations per unit timewhich is smaller than the second number of rotations per unit time.