A light emitting device, comprising: a plurality of scan lines (S1 to S4) in a first direction; a plurality of data lines (D1 to D4) in a second direction different from the first direction; a panel having a plurality of pixels (E11 to E44) formed on emitting areas that the data lines (D1 to D4) and the scan lines (S1 to S4) cross; a control circuit which detects a gray scale of a first display data and a second display data inputted from outside in sequence and generates a plurality of control signals (CS1 to CS4) for controlling a discharge level according to the detected gray scales of the second display data; characterized in that the light emitting device further comprises a discharging circuit including a plurality of zener diodes (ZD1 to ZD4) and a plurality of variable resistors (R1 to R4) connected between the data lines (D1 to D4) and a ground in serial, wherein the variable resistors (R1 to R4) discharge the data lines (D1 to D4) to a different discharging level according to the control signal transmitted from the control circuit during the discharging time, and wherein the zener diodes (ZD1 to ZD4) discharge the data lines (D1 to D4) to a predetermined discharge level independently of the gray scale of the second display data; and a pre-charge circuit which provides a pre-charge current to the data lines (D1 to D4) according to the second display data received from the control circuit during a pre-charging time after the discharge time, wherein the control circuit provides the variable resistors (R1 to R4) with the control signal instructing to decrease resistance values of the variable resistors (R1 to R4) so that the discharging level corresponds to the second display data, when the second display data is high gray scale data, wherein the control circuit provides the variable resistors (R1 to R4) with the control signal instructing to increase resistance values of the variable resistors (R1 to R4) so that the discharging level corresponds to the second display data, when the second display data is low gray scale data, wherein the discharging level is a first discharging level when the second display data is high gray scale data, wherein the discharging level is a second discharging level when the second display data is low gray scale data, wherein a gray scale of the low gray scale data is lower than a gray scale of the high gray scale data, and wherein the second discharging level is higher than the first discharging level. a plurality of scan lines (S1 to S4) in a first direction; a plurality of data lines (D1 to D4) in a second direction different from the first direction; a panel having a plurality of pixels (E11 to E44) formed on emitting areas that the data lines (D1 to D4) and the scan lines (S1 to S4) cross; a control circuit which detects a gray scale of a first display data and a second display data inputted from outside in sequence and generates a plurality of control signals (CS1 to CS4) for controlling a discharge level according to the detected gray scales of the second display data; characterized in that the light emitting device further comprises a discharging circuit including a plurality of zener diodes (ZD1 to ZD4) and a plurality of variable resistors (R1 to R4) connected between the data lines (D1 to D4) and a ground in serial, wherein the variable resistors (R1 to R4) discharge the data lines (D1 to D4) to a different discharging level according to the control signal transmitted from the control circuit during the discharging time, and wherein the zener diodes (ZD1 to ZD4) discharge the data lines (D1 to D4) to a predetermined discharge level independently of the gray scale of the second display data; and a pre-charge circuit which provides a pre-charge current to the data lines (D1 to D4) according to the second display data received from the control circuit during a pre-charging time after the discharge time, wherein the control circuit provides the variable resistors (R1 to R4) with the control signal instructing to decrease resistance values of the variable resistors (R1 to R4) so that the discharging level corresponds to the second display data, when the second display data is high gray scale data, wherein the control circuit provides the variable resistors (R1 to R4) with the control signal instructing to increase resistance values of the variable resistors (R1 to R4) so that the discharging level corresponds to the second display data, when the second display data is low gray scale data, wherein the discharging level is a first discharging level when the second display data is high gray scale data, wherein the discharging level is a second discharging level when the second display data is low gray scale data, wherein a gray scale of the low gray scale data is lower than a gray scale of the high gray scale data, and wherein the second discharging level is higher than the first discharging level.