A light emission device comprising a light-emitting element, a transistor and a drive device for supplying an output voltage (Vo) to the light-emitting element, wherein the transistor is connected to the light emitting element and wherein the drive device comprises: a transistor control unit connected to the transistor, wherein the transistor control unit is adapted to drive and control said transistor; an output ground fault protection unit adapted to output an output ground fault detection signal (SCP_OH) corresponding to a voltage level (Vo) at a connection node between the light-emitting element and the transistor; a stop control unit adapted to stop driving of the transistor when the output ground fault detection signal (SCP_OH) indicates an output ground fault; a mask signal generation unit (21, 22) adapted to generate a mask signal (SCPM1_OH) for masking the output ground fault detection signal (SCP_OH); an abnormal state output unit adapted to output an abnormality flag signal (P bus) indicating an abnormal state when the output ground fault detection signal (SCP_OH) indicates the output ground fault, wherein the abnormal state output unit is capable of outputting the abnormality flag signal (P bus) indicating a normal state during a period in which the output ground fault detection signal (SCP_OH) is masked by the mask signal (SCPM1_OH); and a reference voltage generation unit adapted to generate a reference voltage (Vreg) from a power supply voltage, wherein the output ground fault protection unit is capable to start its operation when the reference voltage (V reg) has reached a predetermined under voltage lock out, UVLO, release voltage upon startup of the light emission device; wherein the light emission device is characterised in that the mask signal generation unit (21, 22) is adapted to generate the mask signal as a signal rising to a masking level, wherein the mask signal (SCPM1_OH) starts to rise as the reference voltage (Vreg) starts to rise upon startup of the light emission device, and wherein the masking level indicates a masking state such that the abnormal state output unit outputs the abnormality flag signal (Pbus) indicating the normal state during a period in which the output ground fault detection signal (SCP_OH) is masked by the mask signal (SCPM1_OH). a transistor control unit connected to the transistor, wherein the transistor control unit is adapted to drive and control said transistor; an output ground fault protection unit adapted to output an output ground fault detection signal (SCP_OH) corresponding to a voltage level (Vo) at a connection node between the light-emitting element and the transistor; a stop control unit adapted to stop driving of the transistor when the output ground fault detection signal (SCP_OH) indicates an output ground fault; a mask signal generation unit (21, 22) adapted to generate a mask signal (SCPM1_OH) for masking the output ground fault detection signal (SCP_OH); an abnormal state output unit adapted to output an abnormality flag signal (P bus) indicating an abnormal state when the output ground fault detection signal (SCP_OH) indicates the output ground fault, wherein the abnormal state output unit is capable of outputting the abnormality flag signal (P bus) indicating a normal state during a period in which the output ground fault detection signal (SCP_OH) is masked by the mask signal (SCPM1_OH); and a reference voltage generation unit adapted to generate a reference voltage (Vreg) from a power supply voltage, wherein the output ground fault protection unit is capable to start its operation when the reference voltage (V reg) has reached a predetermined under voltage lock out, UVLO, release voltage upon startup of the light emission device; wherein the light emission device is characterised in that the mask signal generation unit (21, 22) is adapted to generate the mask signal as a signal rising to a masking level, wherein the mask signal (SCPM1_OH) starts to rise as the reference voltage (Vreg) starts to rise upon startup of the light emission device, and wherein the masking level indicates a masking state such that the abnormal state output unit outputs the abnormality flag signal (Pbus) indicating the normal state during a period in which the output ground fault detection signal (SCP_OH) is masked by the mask signal (SCPM1_OH).