摘要 |
A lighting device comprising a hermetically sealed vessel having a light transmissive property, a gas filled in the hermetically sealed vessel and configured to emit a first light having wavelength when excited by electron, the wavelength of the first light has a range from vacuum ultraviolet to visual light, an electron source disposed within the hermetically sealed vessel, the electron source configured to emit the electron when an operation voltage is applied, anode electrode disposed within the hermetically sealed vessel, a phosphor configured to emit the second light when excited by the first light. The electron source is configured to emit the electron having energy distribution when the electron source receives the emission voltage. The energy distribution having a peak energy. The peak energy is higher than an excitation energy of the gas. The peak energy is lower than an ionization energy of the gas. |