Abstract: A phosphor according to the present disclosure includes a first crystal phase added with an activator agent, a second crystal phase higher in thermal conductivity than the first crystal phase, and a third crystal phase which is disposed between the first crystal phase and the second crystal phase, and is same in crystal structure as the first crystal phase, and is smaller in additive amount of the activator agent than the first crystal phase.

Abstract: A ceramic composite according to the present disclosure has a phosphor phase containing an activator and a phosphor and a matrix phase containing MgO as a light transmissive ceramic material. The ceramic composite is made of an inorganic material, and the content of the phosphor phase is so set that the volume ratio of the phosphor phase to the entire phase including the matrix phase and the phosphor phase is lower than or equal to 20 vol %.

Abstract: A wavelength converter according to the present disclosure includes a wavelength conversion layer that has a first surface and a second surface different from the first surface and converts excitation light that belongs to a first wavelength band into fluorescence that belongs to a second wavelength band different from the first wavelength band, a first light transmissive member that has a third surface on which the excitation light is incident and a fourth surface different from the third surface and transmits at least the excitation light, and a first layer provided between the first surface of the wavelength conversion layer and the fourth surface of the first light transmissive member, which are surfaces facing each other. The refractive index of the first light transmissive member is greater than the refractive index of the wavelength conversion layer, and the first layer transmits the excitation light and reflects the fluorescence.

Abstract: A ceramic composite according to the present disclosure has a phosphor phase containing an activator and a phosphor and a matrix phase containing MgO as a light transmissive ceramic material. The ceramic composite is made of an inorganic material, and the content of the phosphor phase is so set that the volume ratio of the phosphor phase to the entire phase including the matrix phase and the phosphor phase is lower than or equal to 20 vol %.

Abstract: A wavelength converter according to the present disclosure includes a wavelength conversion layer that has a first surface and a second surface different from the first surface and converts excitation light that belongs to a first wavelength band into fluorescence that belongs to a second wavelength band different from the first wavelength band, a first light transmissive member that has a third surface on which the excitation light is incident and a fourth surface different from the third surface and transmits at least the excitation light, and a first layer provided between the first surface of the wavelength conversion layer and the fourth surface of the first light transmissive member, which are surfaces facing each other. The refractive index of the first light transmissive member is greater than the refractive index of the wavelength conversion layer, and the first layer transmits the excitation light and reflects the fluorescence.

Abstract: A wavelength converter according to an aspect of the present disclosure includes a wavelength conversion layer that converts excitation light in terms of wavelength to generate fluorescence, and a first reflection member that reflects the fluorescence and is so provided as to incline with respect to a light exiting surface which is a surface of the wavelength conversion layer and via which the fluorescence exits.

Abstract: A phosphor according to the present disclosure includes a first crystal phase added with an activator agent, a second crystal phase higher in thermal conductivity than the first crystal phase, and a third crystal phase which is disposed between the first crystal phase and the second crystal phase, and is same in crystal structure as the first crystal phase, and is smaller in additive amount of the activator agent than the first crystal phase.

Abstract: A light source apparatus according to an aspect of the present disclosure includes an excitation light source and a wavelength converter including a transparent phosphor and a base. The wavelength converter has a light incident area, a first area, and a second area, and the wavelength converter includes a second reflector (angle changer) provided in a portion corresponding to the second area.

Abstract: A wavelength converter according to an aspect of the present disclosure includes a wavelength conversion layer that converts excitation light in terms of wavelength to generate fluorescence, and a first reflection member that reflects the fluorescence and is so provided as to incline with respect to a light exiting surface which is a surface of the wavelength conversion layer and via which the fluorescence exits.

Abstract: A light source apparatus according to an aspect of the present disclosure includes an excitation light source and a wavelength converter including a transparent phosphor and a base. The wavelength converter has a light incident area, a first area, and a second area, and the wavelength converter includes a second reflector (angle changer) provided in a portion corresponding to the second area.

Abstract: A wavelength conversion element includes a wavelength conversion layer having a first surface on which excitation light is incident and a second surface provided on the side opposite the first surface, the wavelength conversion layer wavelength-converting the excitation light into converted light having a wavelength longer than the wavelength of the excitation light, a scattering element contained in the wavelength conversion layer and having a size smaller than or equal to the wavelength of the excitation light, and an incident angle changing section that changes the angle of incidence of the converted light with respect to the first surface or the second surface.

Abstract: A wavelength conversion element includes a base material and a phosphor layer that contains a phosphor emitting fluorescence upon incidence of excitation light and is provided on the base material, in which the phosphor layer includes a first surface on which excitation light (blue light) is incident and a second surface facing the base material, and a plurality of regions with different absorption coefficients of the excitation light between the first surface and the second surface.

Abstract: A wavelength conversion element includes a base material and a phosphor layer that contains a phosphor emitting fluorescence upon incidence of excitation light and is provided on the base material, in which the phosphor layer includes a first surface on which excitation light (blue light) is incident and a second surface facing the base material, and a plurality of regions with different absorption coefficients of the excitation light between the first surface and the second surface.

Abstract: A wavelength conversion device according to an aspect of the invention includes a rotary device having a rotary part rotating around an axis, a base member rotated around the axis by the rotary device, an inorganic wavelength conversion element provided to the base member, and a heat radiation member fixed to the base member, the heat radiation member has a ring-like shape surrounding the axis, and spreads outward in a radial direction of the axis beyond the base member, and the heat radiation member and the base member are formed separately from each other.

Abstract: A light source device includes a phosphor layer having a side surface, a bottom surface, and an upper surface opposed to the bottom surface, a substrate disposed on the bottom surface side of the phosphor layer, and a reflecting member disposed outside the phosphor layer. The phosphor layer generates fluorescence in response to irradiation with excitation light. The fluorescence generated in the phosphor layer is emitted from the upper surface and the side surface. The fluorescence emitted from the side surface enters the reflecting member.

Abstract: A light source device includes a phosphor layer having a side surface, a bottom surface, and an upper surface opposed to the bottom surface, a substrate disposed on the bottom surface side of the phosphor layer, and a reflecting member disposed outside the phosphor layer. The phosphor layer generates fluorescence in response to irradiation with excitation light. The fluorescence generated in the phosphor layer is emitted from the upper surface and the side surface. The fluorescence emitted from the side surface enters the reflecting member.

Abstract: An image forming apparatus includes a fusing unit with a heating member arranged to fuse toner to a printing paper, a heat source arranged to heat the heating member, a thermal sensor arranged to measure a surface temperature of the heating member, an electricity controlling unit arranged to control electricity supplied to the heat source based on a temperature measured by the thermal sensor, a first temperature controlling unit arranged to control the surface temperature of the heating member in STANDBY mode to gradually rise to an upper limit temperature by turning on/off electricity to the heat source with an electricity controlling unit, and a second temperature controlling unit arranged to control the surface temperature of the heating member in STANDBY mode to gradually fall to a lower limit temperature by turning on/off electricity to the heat source with the electricity controlling unit.

Abstract: A screen in which observation distance may be adjusted while maintaining image brightness and a projection system using the screen. In a light control layer of a screen, a first angle region that determines a diffusion distribution of a reflected light is different according to the screen position in a control direction in which light diffusion control is performed. Accordingly, a diffusion distribution of image light emitted from a screen surface is adjusted to be tilted downward by an upper end and upward by a lower end according to the screen position. Thus, for example, a size of a diffused angle range is maintained to be 30°, and a direction in which the image light is diffusion-emitted corresponds to an assumed position of an observer. The projection image can be observed while maintaining brightness of an image and the observation distance L can be adjusted to be short.

Abstract: A screen which reflects light emitted from a projector includes a light diffusion layer through which light incident from a specific angular region is diffused and transmitted and through which light incident from the other angular region is transmitted straight; area pairs having a mirror forming area and a non-mirror forming area; a light transmissive layer having a back surface, on which the area pairs are disposed, and an opposite surface being bonded to a back side of the light diffusion layer; and a specular reflection film formed on a back surface of each mirror forming area. An inclination of the mirror forming area with respect to a normal line of the screen close to the projector becomes larger than the inclination of the mirror forming area far from the projector within a cross section perpendicular to the mirror forming areas inside the screen.

Abstract: A fusing unit includes a heat roller and a press roller, which fuse a toner image fused to a recording sheet; a first separating pawl contacting a circumferential surface of the heat roller and separating the recording sheet from the heat roller; second separating pawls that are spaced from the first separating pawl in an axial direction to contact the circumferential surface of the heat roller and separate the recording sheet from the heat roller; a first rotatable guide in the first separating pawl that guides the recording sheet to a sheet discharge guide of an exit feed path while changing its orientation; a second rotatable guide provided in each of the second separating pawls which guides the recording sheet to a sheet discharge guide of an exit feed path while changing an orientation of the recording sheet; and a fusing feed path that reaches the sheet discharge guide.