| 摘要 |
PROBLEM TO BE SOLVED: To provide a display device, a projection device, and a projection method, in which energy efficiency is increased in use for digital signage or the like.SOLUTION: A projection device 10 includes a light source, a display element 51 irradiated with light from the light source, to emit image light, image range acquisition means for acquiring a predetermined image range from an image to be projected by the display element 51, and a light guide optical system including range changing means (185a and 185b) changing a range where the light source irradiates the display element, according to the image range acquired by the image range acquisition means and irradiating the display element with light source light emitted from the light source. |
