Patent ID: 8803423

Claim:
A fluorescent lamp comprising: a front substrate and a back substrate facing each other; a container configured of walls surrounding the front substrate and the back substrate; an electron source placed on a front substrate side of the back substrate and emitting hot electrons; a fluorescent material placed on a back substrate side of the front substrate, absorbing ultraviolet rays, and performing visible light emission; a noble gas or a molecular gas enclosed in the container; and electrodes provided on the front substrate and the back substrate, wherein the hot electrons emitted into the noble gas or the molecular gas are collected by applying an anode voltage between the electrodes, and a current luminous efficiency obtained by dividing a luminance L of the visible light emission by an anode current density is proportional to a value of an anode electric field obtained by dividing the anode voltage by a substrate distance between the front substrate and the back substrate, wherein the noble gas or the molecular gas has a pressure equal to or higher than 10 kPa, the anode voltage is equal to or lower than 240 V, and the substrate distance is equal to or smaller than 0.4 mm.