Electroluminescent cell and electroluminescent particle
An electroluminescent cell of dispersion type-like construction includes a pair of electrodes and an electroluminescent layer arranged between the electrodes. A plurality of electroluminescent particles, including a dielectric core and a phosphor-covering layer formed on the outside of said dielectric core, are dispersed in a dielectric binder of the electroluminescent layer. When a voltage is applied across the electroluminescent cell, an average electric-field intensity applied to the phosphor-covering layers of the electroluminescent particles is 1.5 or more times an average electric-field intensity applied to the entire electroluminescent layer.
1 . An electroluminescent cell comprising:
a pair of electrodes; and
an electroluminescent layer, arranged between said pair of electrodes, in which a plurality of electroluminescent particles, including a dielectric core and a phosphor-covering layer formed on the outside of said dielectric core, are dispersed in a dielectric binder;
wherein, when a voltage is applied across said electroluminescent cell, an average electric-field intensity applied to the phosphor-covering layers of said plurality of electroluminescent particles is 1.5 or more times an average electric-field intensity applied to the entire electroluminescent layer.
2 . The electroluminescent cell as set forth in claim 1 , wherein an average core diameter of the dielectric cores of said plurality of electroluminescent particles is 1.2 μm or greater and a layer thickness of said electroluminescent layer is 100 μm or less.
3 . The electroluminescent cell as set forth in claim 1 , wherein an average layer thickness r 1 of the phosphor-covering layers of said plurality of electroluminescent particles and an average radius r 2 of the dielectric cores have a relationship of r 2 /r 1 ≧1.0.
4 . The electroluminescent cell as set forth in claim 2 , wherein an average layer thickness r 1 of the phosphor-covering layers of said plurality of electroluminescent particles and an average radius r 2 of the dielectric cores have a relationship of r 2 /r 1 ≧1.0.
5 . The electroluminescent cell as set forth in claim 1 , wherein a dielectric constant ε 1 of said phosphor-covering layer and a dielectric constant ε 2 of said dielectric core have a relationship of ε 2 /ε 1 >2.0.
6 . The electroluminescent cell as set forth in claim 2 , wherein a dielectric constant ε 1 of said phosphor-covering layer and a dielectric constant ε 2 of said dielectric core have a relationship of ε 2 /ε 1 >2.0.
7 . The electroluminescent cell as set forth in claim 3 , wherein a dielectric constant ε 1 of said phosphor-covering layer and a dielectric constant ε 2 of said dielectric core have a relationship of ε 2 /ε 1 >2.0.
8 . An electroluminescent cell comprising:
a pair of electrodes; and
an electroluminescent layer, arranged between said pair of electrodes, in which a plurality of electroluminescent particles, including a dielectric core, a phosphor-covering layer formed on the outside of said dielectric core, and a dielectric-covering layer formed on the outside of said phosphor-covering layer, are dispersed in a dielectric binder;
wherein, when a voltage is applied across said electroluminescent cell, an average electric-field intensity applied to the phosphor-covering layers of said plurality of electroluminescent particles is 1.5 or more times an average electric-field intensity applied to the entire electroluminescent layer.
9 . The electroluminescent cell as set forth in claim 8 , wherein an average core diameter of the dielectric cores of said plurality of electroluminescent particles is 1.2 μm or greater and a layer thickness of said electroluminescent layer is 100 μm or less.
10 . The electroluminescent cell as set forth in claim 8 , wherein an average layer thickness r 1 of the phosphor-covering layers of said plurality of electroluminescent particles, an average radius r 2 of the dielectric cores, and an average layer thickness r 3 of the dielectric-covering layers have a relationship of r 2 /r 1 ≧1.0 and r 3 /(r 1 +r 2 )<0.50.
11 . The electroluminescent cell as set forth in claim 9 , wherein an average layer thickness r 1 of the phosphor-covering layers of said plurality of electroluminescent particles, an average radius r 2 of the dielectric cores, and an average layer thickness r 3 of the dielectric-covering layers have a relationship of r 2 /r 1 ≧1.0 and r 3 /(r 1 +r 2 )<0.50.
12 . The electroluminescent cell as set forth in claim 8 , wherein a dielectric constant ε 1 of said phosphor-covering layer, a dielectric constant ε 2 of said dielectric core, and a dielectric constant ε 3 of said dielectric-covering layer have a relationship of ε 2 /ε 1 >2.0 and ε 3 /ε 1 <20.
13 . The electroluminescent cell as set forth in claim 9 , wherein a dielectric constant ε 1 of said phosphor-covering layer, a dielectric constant ε 2 of said dielectric core, and a dielectric constant ε 3 of said dielectric-covering layer have a relationship of ε 2 /ε 1 >2.0 and ε 3 /ε 1 <20.
14 . The electroluminescent cell as set forth in claim 10 , wherein a dielectric constant ε 1 of said phosphor-covering layer, a dielectric constant ε 2 of said dielectric core, and a dielectric constant ε 3 of said dielectric-covering layer have a relationship of ε 2 /ε 1 >2.0 and ε 3 /ε 1 <20.
15 . The electroluminescent cell as set forth in claim 1 , wherein said phosphor-covering layer of each of said plurality of electroluminescent particles comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
16 . The electroluminescent cell as set forth in claim 2 , wherein said phosphor-covering layer of each of said plurality of electroluminescent particles comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
17 . The electroluminescent cell as set forth in claim 8 , wherein said phosphor-covering layer of each of said plurality of electroluminescent particles comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
18 . The electroluminescent cell as set forth in claim 9 , wherein said phosphor-covering layer of each of said plurality of electroluminescent particles comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
19 . The electroluminescent cell as set forth in claim 1 , wherein a volume filling ratio for said plurality of electroluminescent particles in said electroluminescent layer is 40% or greater.
20 . The electroluminescent cell as set forth in claim 2 , wherein a volume filling ratio for said plurality of electroluminescent particles in said electroluminescent layer is 40% or greater.
21 . The electroluminescent cell as set forth in claim 8 , wherein a volume filling ratio for said plurality of electroluminescent particles in said electroluminescent layer is 40% or greater.
22 . The electroluminescent cell as set forth in claim 9 , wherein a volume filling ratio for said plurality of electroluminescent particles in said electroluminescent layer is 40% or greater.
23 . An electroluminescent particle comprising:
a dielectric core with a core diameter of 1.2 μm or greater; and
a phosphor-covering layer formed on the outside of said dielectric core.
24 . The electroluminescent particle as set forth in claim 23 , wherein a layer thickness r 1 of the phosphor-covering layer and a radius r 2 of the dielectric core have a relationship of r 2 /r 1 ≧1.0.
25 . The electroluminescent particle as set forth in claim 23 , wherein a dielectric constant ε 1 of said phosphor-covering layer and a dielectric constant ε 2 of said dielectric core have a relationship of ε 2 /ε 1 >2.0.
26 . The electroluminescent particle as set forth in claim 24 , wherein a dielectric constant ε 1 of said phosphor-covering layer and a dielectric constant ε 2 of said dielectric core have a relationship of ε 2 /ε 1 >2.0.
27 . An electroluminescent particle comprising:
a dielectric core with a core diameter of 1.2 μm or greater;
a phosphor-covering layer formed on the outside of said dielectric core; and
a dielectric-covering layer formed on the outside of said phosphor-covering layer.
28 . The electroluminescent particle as set forth in claim 27 , wherein a layer thickness r 1 of said phosphor-covering layer, a radius r 2 of said dielectric core, and a layer thickness r 3 of said dielectric-covering layer have a relationship of r 2 /r 1 ≧1.0 and r 3 /(r 1 +r 2 )<0.50.
29 . The electroluminescent cell as set forth in claim 27 , wherein a dielectric constant ε 1 of said phosphor-covering layer, a dielectric constant ε 2 of said dielectric core, and a dielectric constant ε 3 of said dielectric-covering layer have a relationship of ε 2 /ε 1 >2.0 and ε 3 /ε 1 <20.
30 . The electroluminescent cell as set forth in claim 28 , wherein a dielectric constant ε 1 of said phosphor-covering layer, a dielectric constant ε 2 of said dielectric core, and a dielectric constant ε 3 of said dielectric-covering layer have a relationship of ε 2 /ε 1 >2.0 and ε 3 /ε 1 <20.
31 . The electroluminescent particle as set forth in claim 23 , wherein said phosphor-covering layer comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
32 . The electroluminescent particle as set forth in claim 24 , wherein said phosphor-covering layer comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
33 . The electroluminescent particle as set forth in claim 27 , wherein said phosphor-covering layer comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.
34 . The electroluminescent particle as set forth in claim 28 , wherein said phosphor-covering layer comprises a phosphor including an electroluminescent center that collides with and is excited by a hot electron.