Projector including phosphor

A projector comprising:

• a light source unit
• a spatial light modulator configured to control light from the light source unit for each pixel to form an optical image;
• and
• a projection optical system configured to project the optical image formed by the spatial light modulator onto a target, wherein:
• the light source unit includes a solid-state light source and a wavelength convertor,
• the solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive,
• the wavelength convertor contains at least a red phosphor including Ce as a luminescent center,
• the red phosphor is configured to emit second light upon receiving the green light,
• the second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive,
• the solid-state light source includes a blue laser that is configured to emit the blue light and a green laser that is configured to emit the green light, and
• the projector further includes a dichroic mirror by which the blue light and the green light are coaxially multiplexed to be incident on the wavelength convertor.

A projector comprising:

• a light source unit
• a spatial light modulator configured to control light from the light source unit for each pixel to form an optical image;
• and
• a projection optical system configured to project the optical image formed by the spatial light modulator onto a target, wherein:
• the light source unit includes a solid-state light source and a wavelength convertor,
• the solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive,
• the wavelength convertor contains at least a red phosphor including Ce as a luminescent center,
• the red phosphor is configured to emit second light upon receiving the green light,
• the second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive,
• the wavelength convertor includes a first phosphor layer containing the red phosphor and a second phosphor layer containing at least one selected from the group consisting of a yellow phosphor and a yellow-green phosphor,
• an excitation efficiency of the red phosphor is lower for the blue light than for the green light,
• the second phosphor is excited upon receiving the blue light, and
• the first phosphor layer in the wavelength convertor is closer to a light incident side of the wavelength convertor than the second phosphor layer.

A projector comprising:

• a light source unit;
• a spatial light modulator configured to control light from the light source unit for each pixel to form an optical image;
• a projection optical system configured to project the optical image formed by the spatial light modulator onto a target;
• and
• a control circuit configured to control the light source unit, wherein:
• the light source unit includes a solid-state light source and a wavelength convertor,
• the solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive,
• the wavelength convertor contains at least a red phosphor including Ce as a luminescent center,
• the red phosphor is configured to emit second light upon receiving the green light,
• the second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive,
• the light source unit further includes a transmission-type wheel,
• the transmission-type wheel includes a transmission region and a red phosphor region, the red phosphor region including the wavelength convertor,
• the solid-state light source includes a blue laser that is configured to emit the blue light and a green laser that is configured to emit the green light,
• the control circuit is configured to control the blue laser and the green laser to emit the blue light and the green light, respectively, in a time-divided manner in synchronism with rotation of the transmission-type wheel,
• the transmission region is configured to transmit at least the green light, and
• the spatial light modulator is configured to control the light including the blue light, the green light, and the second light emitted from the light source unit for each pixel.

A projector comprising:

• a light source unit
• a control circuit configured to control the light source unit;
• a spatial light modulator configured to control light from the light source unit for each pixel to form an optical image;
• and
• a projection optical system configured to project the optical image formed by the spatial light modulator onto a target, wherein:
• the light source unit includes a solid-state light source and a wavelength convertor,
• the solid-state light source is configured to emit first light, the first light including blue light with a peak wavelength in a range of 430 to 470 nm, inclusive, and green light with a peak wavelength in a range of 480 to 550 nm, inclusive,
• the wavelength convertor contains at least a red phosphor including Ce as a luminescent center,
• the red phosphor is configured to emit second light upon receiving the green light, the second light has a spectrum with a peak wavelength in a range of 600 to 700 nm, inclusive,
• the light source unit further includes a reflection-type wheel,
• the reflection-type wheel includes a red phosphor region including the wavelength convertor,
• the solid-state light source includes a blue laser that is configured to emit the blue light and a green laser that is configured to emit the green light,
• the red phosphor region has a first surface disposed such that the green light is incident on the first surface,
• the red phosphor region further has a second surface opposite the first surface,
• the reflection-type wheel further includes a reflective layer,
• the reflective layer includes a first region disposed on a second surface side of the red phosphor region and a second region different from the first region,
• the first region configured to reflect the second light when the second light is incident on the first region,
• the second region configured to reflect the green light when the green light is incident on the second region,
• the control circuit is configured to control the blue laser and the green laser to emit the blue light and the green light, respectively, in a time-divided manner in synchronism with rotation of the reflection-type wheel,
• the spatial light modulator controls the light including the blue light, the green light, and the second light emitted from the light source unit for each pixel,
• the reflection-type wheel further includes a scattering region containing a scatterer,
• the scattering region has a third surface disposed such that the green light and the blue light are incident on the third surface,
• the scattering region further has a fourth surface opposite the third surface,
• the second region of the reflective layer is disposed on a fourth surface side of the scattering region and configured to reflect the blue light when the blue light is incident on the second region, and
• the control circuit is configured to control the blue laser and the green laser to emit the blue light and the green light, respectively, in a time-divided manner in synchronism with rotation of the reflection-type wheel such that (a) in case of red projection, the green light is incident on the red phosphor region of the reflection-type wheel, (b) in case of blue projection, the blue light is incident on the scattering region of the reflection-type wheel, and (c) in case of green projection, the green light is incident on the scattering region of the reflection-type wheel.