Projection image display device

A projection image display device, comprising:

• a light source that illuminates light;
• an image forming element that includes a first image forming element that forms a first image, and a second image forming element that forms a second image;
• a color separating and combining unit that includes a first dichroic filter that separates the light from the light source into first illumination light and second illumination light having a wavelength band different from a wavelength band of the first illumination light, the color separating and combining unit emitting the first illumination light to the first image forming element, emitting the second illumination light to the second image forming element, and combining first projection light reflected by the first image forming element and second projection light reflected by the second image forming element;
• and
• a notch filter that is disposed between the light source and the color separating and combining unit, wherein
• the first dichroic filter reflects the first illumination light and the first projection light,
• a first incident angle of the first illumination light with respect to the first dichroic filter is different from a second incident angle of the first projection light with respect to the first dichroic filter,
• the notch filter attenuates light in a first wavelength band including a boundary between the wavelength band of the first illumination light and the wavelength band of the second illumination light,
• when λDM1 is smaller than λDM2, the notch filter satisfies λDM3>λNF2 and λDM1+λDM3/4≤λNF1≤λDM2−λDM3/4,
• when λDM1 iS larger than λDM2, the notch filter satisfies λDM3>λNF2 and λDM2+λDM3/4≤λNF1≤λDM1−λDM3/4,
• λDM1 is a wavelength at which a transmittance of the first dichroic filter with respect to light incident on the first dichroic filter at the first incident angle is 50%,
• λDM2 is a wavelength at which a transmittance of the first dichroic filter with respect to light incident on the first dichroic filter at the second incident angle is 50%,
• λDM3 is a wavelength width between λDM1 and λDM2,
• λNF1 is a center wavelength of the first wavelength band of the notch filter, and
• λNF2 is a full width at half maximum (FWHM) of the first wavelength band of the notch filter.