A light source lighting device includes: a laser light source unit; a converging lens that converges a plurality of light beams emitted from the laser light source unit; a diffuser plate that diffuses a plurality of light beams converged by the converging lens; and a second collimating lens that collimates a light beam diffused by the diffuser plate. The converging lens has an aspherical surface, the second collimating lens has a spherical surface, the aspherical surface of the converging lens has an aspherical surface coefficient that is set to cancel a positive spherical aberration of the second collimating lens. A luminous flux density in a proximity of an optical axis is lower than a luminous flux density in a peripheral part away from the optical axis, the optical axis being an axis of a light beam emitted from the second collimating lens.

A projection display system includes a light source assembly, a wavelength adjusting assembly, and a modulation assembly. The light source assembly is configured to emit projected light. The wavelength adjusting assembly is disposed on an optical path of the projected light for adjusting spectrum of the projected light, and a ratio of luminous efficacy of adjusted projected light to luminous efficacy of monochromatic light corresponding to a dominant wavelength of the projected light is greater than a preset ratio, and color gamut of the adjusted projected light satisfies a preset color gamut coverage. The modulation assembly is disposed on a light exiting path of the wavelength adjusting assembly and configured to modulate light emitted by the wavelength adjusting assembly and output corresponding image light to form projection image.

A projection display system includes a light source assembly, a wavelength adjusting assembly, and a modulation assembly. The light source assembly is configured to emit projected light. The wavelength adjusting assembly is disposed on an optical path of the projected light for adjusting spectrum of the projected light, and a ratio of luminous efficacy of adjusted projected light to luminous efficacy of monochromatic light corresponding to a dominant wavelength of the projected light is greater than a preset ratio, and color gamut of the adjusted projected light satisfies a preset color gamut coverage. The modulation assembly is disposed on a light exiting path of the wavelength adjusting assembly and configured to modulate light emitted by the wavelength adjusting assembly and output corresponding image light to form projection image.

A projector includes a main body and a projection lens. The main body includes a light source, liquid crystal panels that modulate light outputted from the light source, and a lens holder to and from which the projection lens is attachable and detachable. The projection lens projects the light modulated, and the lens holder includes a first lens holding mechanism and a second lens holding mechanism that hold the projection lens.

An illuminator includes a light emitting apparatus which outputs first light belonging to a first wavelength band, a wavelength converter which converts part of the first light into second light belonging to a second wavelength band and causes the second and remainder of the first light to exit, a first optical system with positive power and which the first light enters, an optical element which the remaining first light enters and which reflects either the first or second light and transmits the other, a second optical system with positive power and which the first from the optical element and second light from the converter enter, a third optical system with positive power and causes the first light from the second optical system to enter the converter, and a fourth optical system with positive power and which the second light from the second optical system enters.

An illuminator includes a light emitting apparatus which outputs first light belonging to a first wavelength band, a wavelength converter which converts part of the first light into second light belonging to a second wavelength band and causes the second and remainder of the first light to exit, a first optical system with positive power and which the first light enters, an optical element which the remaining first light enters and which reflects either the first or second light and transmits the other, a second optical system with positive power and which the first from the optical element and second light from the converter enter, a third optical system with positive power and causes the first light from the second optical system to enter the converter, and a fourth optical system with positive power and which the second light from the second optical system enters.

A wavelength conversion element according to the present disclosure includes a substrate, a dichroic layer provided to a first surface of the substrate, an intermediate layer disposed so as to be opposed to the substrate via the dichroic layer, and a wavelength conversion layer disposed so as to be opposed to the dichroic layer via the intermediate layer, and configured to convert light in a first wavelength band into light in a second wavelength band. The dichroic layer has two or more types of refractive index layers having respective refractive indexes different from each other.

A wavelength conversion element according to the present disclosure includes a substrate, a dichroic layer provided to a first surface of the substrate, an intermediate layer disposed so as to be opposed to the substrate via the dichroic layer, and a wavelength conversion layer disposed so as to be opposed to the dichroic layer via the intermediate layer, and configured to convert light in a first wavelength band into light in a second wavelength band. The dichroic layer has two or more types of refractive index layers having respective refractive indexes different from each other.

A light engine includes an image surface, a projected light surface, a projection lens assembly, and a plurality of folding elements. The image surface has three image areas. The projected light surface has three light sources that provide light with different wavelengths. The plurality of folding elements are arranged along a light emitting axis. The image surface and the projected light surface are substantially in parallel with the light emitting axis, and there is an air gap located between the image surface and the projected light surface. The three light sources respectively correspond to the plurality of folding elements and respectively correspond to the three image areas, and the light emitting axis and the projection lens assembly are disposed on the same optical path.

A method includes receiving collimated light from an optical imaging system and dividing the received light into multiple bands of wavelength. Each band is refocused onto a corresponding diffraction grating having an amplitude function matched to a point spread function (PSF) of the optical imaging system. The light that is not filtered out by the diffraction grating is transmitted onto a corresponding pixel array. An image is reconstructed from data provided by the pixel arrays for each band. The intensity of light scattered by each diffraction grating may be detected, with the image being reconstructed as a function of an average value of detected intensity of scattered light used to scale the known zero-order mode profile, which is added to the image on the pixel array.