Patent ID: 7535182

Claim:
A flat panel display device comprising: an electron emission substrate; an image forming substrate spaced apart from the electron emission substrate; a spacer disposed between the electron emission substrate and the image forming substrate; a measuring device including a measuring line formed in a displaying region on the electron emission substrate concurrently with a cathode line, and a first measuring pad formed on a first side and a second measuring pad formed on a second side of a non-displaying region concurrently with a cathode pad; a power supply connected to the first measuring pad to supply a voltage or current thereto; a detector connected to the second measuring pad to detect the voltage or current supplied from the power source; a temperature controlling part for converting the voltage or current detected by the detector into a temperature value and for controlling a temperature of the electron emission substrate; and a cooler for cooling the flat panel display device to be at the temperature controlled by the temperature controlling part.