Light source system and light-emitting device

A light-emitting device, comprising a light source system, wherein the light source system comprises:

• an array of light-emitting diodes, wherein the light-emitting diodes comprise light-emitting diode chips;
• a collimating lens group located on a light path of light emitted by the array of the light-emitting diodes, wherein the collimating lens group is configured to collimate light beams emitted by the light-emitting diode chips;
• and
• a fly-eye lens arranged on a light path of light outputted from the collimating lens group, wherein the fly-eye lens comprises micro lens units corresponding to the light-emitting diode chips, and for at least one light-emitting diode chip of the light-emitting diode chips, an image formed by each of the at least one light-emitting diode chip on surfaces of the micro lens units is completely within a surface of one of the micro lens units,
• wherein the fly-eye lens comprises a front fly-eye lens sub-unit and a back fly-eye lens sub-unit, wherein the back fly-eye lens sub-unit is located at a focal plane of the front fly-eye lens sub-unit.