Light-emitting element driving device

A light-emitting element driving device having connection terminals for a plurality of channels, the light-emitting element driving device being configured to be operable, for each channel, to supply a light-emitting unit provided between a wire to which a driving voltage is applied and a connection terminal with a driving current for the light-emitting unit via the connection terminal,

• the light-emitting element driving device comprising:
• a voltage generation circuit configured to generate, based on the driving voltage, a first voltage at a first node and a second voltage at a second node;
• and
• a fault detection circuit configured to execute a fault detection process in a period in which each light-emitting unit is not supplied with the driving current,
• wherein
• for each channel, a switch circuit is provided between the connection terminal and the voltage generation circuit,
• the first and second voltages are lower than the driving voltage and, with each connection terminal cut off from the first and second nodes, the second voltage is lower than the first voltage,
• the fault detection circuit controls a state of each switch circuit and, in the fault detection process, brings into an evaluation state two switch circuits corresponding to, among a plurality of connection terminals, two adjacent connection terminals,
• in the evaluation state, of the two connection terminals, one connection terminal is connected to the second node and another connection terminal is connected to the first node, and
• in the fault detection process, the fault detection circuit detects a resistance value abnormality between the two connection terminals based on a voltage at the one connection terminal in the evaluation state.