| 摘要 |
PROBLEM TO BE SOLVED: To provide an image projection device that suppresses a temperature distribution occurring by light absorption of a polarization beam splitter film, suppresses a variation of optical elasticity in which a phase difference occurs in polarization due to occurrence of birefringence accompanied by an internal stress arising from the temperature distribution, and enables improvement of a contrast characteristic of an image.SOLUTION: An image projection device has: a first optical system that illuminates an image display element with different color light and synthesizes different color light from the image display element; and a second optical system that projects an image of the image display element having the color synthesized on an irradiated surface. The first optical system has a polarization beam splitter in which a polarization beam splitter film transmitting first polarization light and reflecting second polarization light is sandwiched between the first optical element and the second optical element, and let an optical elasticity constant of the first optical element be denoted as k1, thermal conductivity thereof be denoted as a1, an optical elasticity constant of the second optical element be denoted as k2, and thermal conductivity thereof be denoted as a2, respective values fall within a predetermined range. |
