| abstract |
A phosphorescence pigment 18 applied to a surface of a reticle 11 contains at least one of a phosphorescence phosphor selected from SrAl 2 O 4 : Eu, Dy; Sr 4 Al 14 O 25 : Eu, Dy; and CaAl 2 O 4 : Eu, Nd. The phosphorescence pigment applied to the surface of the reticle 11 emits light over a long period of time after being excited and ensures satisfactory visibility over a long period of time even in dark places. The particle diameter of the phosphorescence pigment 18 is no smaller than 1.5 μm and no greater than 10 μm at D 50 . The phosphorescence pigment 18 is applied with a microscopic and sharp shape and thus improves visibility even in dark places. The phosphorescent pigment is applied in an amount that is no less than 1.2 mg/cm 2 and no more than 50 mg/cm 2 This obtains appropriate luminance and improves visibility even in dark places. |