ILLUMINATION DEVICE AND PROJECTOR

Japanese Patent JP2021189390

A

To achieve an illumination device excellent in light utilization efficiency.SOLUTION: An illumination device comprises: a first light emitting element that emits first light; a second light emitting element that emits second light; a wavelength conversion element that has a first surface on which the first light and the second light are incident, and a second surface; a first optical element that reflects one of the first light and second light and third light and transmits the other; a first condensing optical system that is provided between the light emitting elements and the first optical element and has a positive power; and a second condensing optical system that is provided between the first optical element and the wavelength conversion element. The second condensing optical system has a focal point between a principal point of the second condensing optical system and the second surface of the wavelength conversion element. When C1 and D1 are the size in a longitudinal direction and the size in a short direction of light emission surfaces, and A1 and B1 are the size in the longitudinal direction and the size in the short direction of a cross section perpendicular to a principal ray of a light beam including the first light and the second light between the light emitting elements and the first optical element, the formula (1) is satisfied. (1) D1/C1