A projector comprising: a blue light source configured to emit blue illumination light; an infrared light source configured to emit infrared illumination light; a phosphor configured to convert a part of the blue illumination light into yellow illumination light and to reflect the yellow illumination light and another part of the blue illumination light; a first dichroic mirror configured to reflect the blue illumination light and to allow penetration of the yellow illumination light; a second dichroic mirror configured to allow penetration of the blue illumination light and the yellow illumination light and to reflect the infrared illumination light to synthesize the blue illumination light, the yellow illumination light, and the infrared illumination light with one another; a third dichroic mirror configured to separate the blue illumination light, the yellow illumination light, and the infrared illumination light, which are synthesized with one another by the second dichroic mirror, into the blue illumination light, the yellow illumination light, and the infrared illumination light; a fourth dichroic mirror configured to separate the yellow illumination light and the infrared illumination light into red illumination light, the infrared illumination light, and green illumination light, a light source controller configured to switch on and off of each of the blue light source and the infrared light source in such a way that the blue light source and the infrared light source are alternately turned on and off; a first image display element configured to modulate first illumination light in which red illumination light and infrared illumination light are alternately switched, based on an image signal for a visible light image and an image signal for an infrared light image, respectively, and to emit first image light in which red image light and infrared image light are alternately switched; a second image display element configured to modulate green illumination light based on a green image signal, and to emit green image light, a third image display element configured to modulate blue illumination light based on a blue image signal, and to emit blue image light; a synthesizer configured to synthesize the first image light, the green image light, and the blue image light with one another, and to obtain synthesized image light; and a projection unit configured to project the synthesized image light. a blue light source configured to emit blue illumination light; an infrared light source configured to emit infrared illumination light; a phosphor configured to convert a part of the blue illumination light into yellow illumination light and to reflect the yellow illumination light and another part of the blue illumination light; a first dichroic mirror configured to reflect the blue illumination light and to allow penetration of the yellow illumination light; a second dichroic mirror configured to allow penetration of the blue illumination light and the yellow illumination light and to reflect the infrared illumination light to synthesize the blue illumination light, the yellow illumination light, and the infrared illumination light with one another; a third dichroic mirror configured to separate the blue illumination light, the yellow illumination light, and the infrared illumination light, which are synthesized with one another by the second dichroic mirror, into the blue illumination light, the yellow illumination light, and the infrared illumination light; a fourth dichroic mirror configured to separate the yellow illumination light and the infrared illumination light into red illumination light, the infrared illumination light, and green illumination light, a light source controller configured to switch on and off of each of the blue light source and the infrared light source in such a way that the blue light source and the infrared light source are alternately turned on and off; a first image display element configured to modulate first illumination light in which red illumination light and infrared illumination light are alternately switched, based on an image signal for a visible light image and an image signal for an infrared light image, respectively, and to emit first image light in which red image light and infrared image light are alternately switched; a second image display element configured to modulate green illumination light based on a green image signal, and to emit green image light, a third image display element configured to modulate blue illumination light based on a blue image signal, and to emit blue image light; a synthesizer configured to synthesize the first image light, the green image light, and the blue image light with one another, and to obtain synthesized image light; and a projection unit configured to project the synthesized image light.