A wavelength conversion element includes a turntable, a first spoiler structure and a second spoiler structure. The turntable has a supporting surface and a back surface opposite to the supporting surface. The first spoiler structure is disposed on the supporting surface and arranged along a first track surrounding a center of the turntable. The second spoiler structure is disposed on the back surface and arranged along a second track surrounding the center. A centroid of at least one of the first spoiler structure and the second spoiler structure is deviated from the center. A projection device adopting the aforementioned wavelength conversion element is also provided. The wavelength conversion element of the invention can reduce the initial unbalance and the projection device of the invention can improve the durability.

A projection system includes a light source unit, a spatial light modulation unit, and a projection optical system. Light source unit includes an optical fiber, a first light source part, and a second light source part. Optical fiber includes a light incident portion, a light emerging portion and a wavelength-converting portion. Wavelength-converting portion is disposed between light incident portion and light emerging portion. Wavelength-converting portion includes wavelength-converting elements. Wavelength-converting elements are able to be excited by excitation light to produce spontaneous emission of light having a longer wavelength than excitation light, and also excited by amplified spontaneous emission of light. First light source part makes excitation light incident on light incident portion. Second light source part makes seed light incident on light incident portion. Seed light causes wavelength-converting elements excited by excitation light or amplified spontaneous emission of light to produce stimulated emission of light.

A projection device, including an illumination light source, an electrochromic module, at least one light valve, and a projection lens, is provided. The illumination light source provides an illumination beam. The electrochromic module is disposed on a transmission path of the illumination beam. The electrochromic module includes at least one electrochromic element, and sequentially maintains or changes a wavelength of the illumination beam penetrating the at least one electrochromic element. The at least one light valve is disposed on the transmission path of the illumination beam transmitted by the electrochromic module to convert the illumination beam into an image beam. The projection lens is disposed on a transmission path of the image beam to project the image beam out of the projection device. The projection device and the use method thereof provided by the disclosure may change the color light output or the color space of a display image.

A wavelength converter includes a base having a first surface, a wavelength conversion part that has a second surface facing the first surface and converts first light that belongs to a second wavelength band into fluorescence that belongs to a second wavelength band different from the first wavelength band, junctions that join the wavelength conversion part and the base to each other, and an air layer located in a region that the first light enters and surrounded by the wavelength conversion part, the base, and the junctions. The first surface of the base has a first region curved in a direction, and the second surface of the wavelength conversion part has a second region facing the first region and curved in the same direction.

A light source apparatus includes a first light source that includes a plurality of first light emitters arranged in a row along a first direction and emits a first luminous flux, a second light source that includes a plurality of second light emitters arranged in a row along a second direction and emits a second luminous flux in a direction in which the first luminous flux is emitted, and a combiner that combines the first and second luminous fluxes with each other to produce combined light and outputs the combined light to an irradiated region. The combined light has a combined light intensity distribution in which a first region where a light intensity of the first luminous flux is maximized and a second region where a light intensity of the second luminous flux is maximized do not overlap with each other.

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.

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 light source apparatus according to an aspect of the present disclosure includes a light emitter that outputs first light, a wavelength conversion member that converts the first light into second light, an output section that outputs the second light, and a light collection member. The output section includes a first end section that faces the wavelength conversion member, a second end section that is located at the side opposite from the first end section along a center axis, and a tapering section that has a cross-sectional area that is perpendicular to the center axis and gradually decreases from the first end section toward the second end section, and the tapering section has a light output surface which inclines with respect to the center axis and via which the second light exits. The light collection member includes a third end section that is relatively close to the wavelength conversion member, a fourth end section that is located at the side opposite from the third end section, and a reflection surface that faces the light output surface and reflects the second light. At least a portion of the reflection surface of the light collection member, the portion facing the fourth end section, is separate from the light output surface at the side facing the second end section of the output section.

A light guiding unit of the present disclosure includes a light guiding member, an angle conversion member, and an adhesive. The light guiding member has an output end surface crossing longitudinal directions of the light guiding member and a side surface crossing the output end surface. The angle conversion member has an incident end surface entered by the light output from the output end surface. In a sectional view orthogonal to the output end surface, a dimension of the incident end surface is larger than a dimension of the output end surface. A part of the adhesive is provided between the output end surface and the incident end surface and another part of the adhesive is provided to cover a part of the side surface. In the sectional view orthogonal to the output end surface, a dimension of the adhesive provided to cover the part of the side surface is equal to or larger than the dimension of the output end surface and equal to or smaller than the dimension of the incident end surface, and the dimension of the adhesive is gradually larger from the side surface toward the incident end surface.

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.