FLUORESCENT PLATE, WAVELENGTH CONVERSION MEMBER, AND LIGHT SOURCE DEVICE
A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, and a plurality of voids. The plurality of voids include a plurality of particular voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller. In a cross section of the fluorescent plate, the ratio of the number of the particular voids having a circularity greater than 0.6 and 1 or less to the total number of the plurality of particular voids is 50% or greater.
1 . A fluorescent plate comprising:
a fluorescent phase which emits fluorescence by excitation light, and
a plurality of voids, wherein
the plurality of voids include a plurality of particular voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller, and,
in a cross section of the fluorescent plate, a ratio of the number of the particular voids having a circularity greater than 0.6 and 1 or less to the total number of the plurality of particular voids is 50% or greater.
2 . The fluorescent plate according to claim 1 , wherein
the ratio of the number of the particular voids having a circularity greater than 0.6 and 1 or less to the total number of the plurality of particular voids 70% or greater.
3 . The fluorescent plate according to claim 1 , wherein
the ratio of the number of the particular voids having a circularity less than 0.4 to the total number of the plurality of particular voids is 8% or less.
4 . The fluorescent plate according to claim 3 , wherein
the ratio of the number of the particular voids having a circularity less than 0.4 to the total number of the plurality of particular voids is 3% or less.
5 . The fluorescent plate according to claim 1 ,
which further includes a light-transmitting phase which allows passage of the excitation light, and
in a cross section of the fluorescent plate including cross sections of the voids, a ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate is 95% or lower.
6 . A wavelength conversion member comprising:
the fluorescent plate as recited in claim 1 , and
a reflection member which is attached to the fluorescent plate and which reflects the excitation light and the fluorescence.
7 . The wavelength conversion member according to claim 6 ,
which further includes a heat radiation member for radiating heat of the fluorescent plate to an outside atmosphere.
8 . A light source device comprising:
the wavelength conversion member as recited in claim 6 , and
a light source which radiates the excitation light to the fluorescent plate.
9 . The fluorescent plate according to claim 2 , wherein
the ratio of the number of the particular voids having a circularity less than 0.4 to the total number of the plurality of particular voids is 8% or less.
10 . The fluorescent plate according to claim 9 , wherein
the ratio of the number of the particular voids having a circularity less than 0.4 to the total number of the plurality of particular voids is 3% or less.
11 . The fluorescent plate according to claim 2 ,
which further includes a light-transmitting phase which allows passage of the excitation light, and
in a cross section of the fluorescent plate including cross sections of the voids, a ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate is 95% or lower.
12 . The fluorescent plate according to claim 3 ,
which further includes a light-transmitting phase which allows passage of the excitation light, and
in a cross section of the fluorescent plate including cross sections of the voids, a ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate is 95% or lower.
13 . The fluorescent plate according to claim 4 ,
which further includes a light-transmitting phase which allows passage of the excitation light, and
in a cross section of the fluorescent plate including cross sections of the voids, a ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate is 95% or lower.
14 . A wavelength conversion member comprising:
the fluorescent plate as recited in claim 2 , and
a reflection member which is attached to the fluorescent plate and which reflects the excitation light and the fluorescence.
15 . A wavelength conversion member comprising:
the fluorescent plate as recited in claim 3 , and
a reflection member which is attached to the fluorescent plate and which reflects the excitation light and the fluorescence.
16 . A wavelength conversion member comprising:
the fluorescent plate as recited in claim 4 , and
a reflection member which is attached to the fluorescent plate and which reflects the excitation light and the fluorescence.
17 . A wavelength conversion member comprising:
the fluorescent plate as recited in claim 5 , and
a reflection member which is attached to the fluorescent plate and which reflects the excitation light and the fluorescence.
18 . The wavelength conversion member according to claim 14 ,
which further includes a heat radiation member for radiating heat of the fluorescent plate to an outside atmosphere.
19 . The wavelength conversion member according to claim 15 ,
which further includes a heat radiation member for radiating heat of the fluorescent plate to an outside atmosphere.
20 . A light source device comprising:
the wavelength conversion member as recited in claim 7 , and
a light source which radiates the excitation light to the fluorescent plate.