Light-emitting device and method of driving light-emitting device

A light-emitting device comprising:

• first to Nth light-emitting panels, wherein N is a natural number larger than 1;
• first to Nth DC/DC converters, wherein the ith DC/DC converter is electrically connected to the ith light-emitting panel where i is a natural number arbitrarily selected from 1 to N;
• a power control circuit electrically connected to the first to Nth DC/DC converters;
• and
• a photosensor electrically connected to the power control circuit,
• wherein the power control circuit is configured to control a current which is output from the ith DC/DC converter to the ith light-emitting panels.

A method for driving a light-emitting device, the method comprising the steps of:

• sequentially supplying a reference current to first to Nth light-emitting panels, wherein N is a natural number larger than 1;
• sequentially measuring illuminances of the first to Nth light-emitting panels at the reference current;
• and
• supplying each of the first to Nth light-emitting panels with a respective corrected current on the basis of the measured illuminances of the first to Nth light-emitting panels at the reference current.