Light source device and display apparatus

A light source device which includes a light guide plate configured to emit light entered through one side surface from a front surface thereof, a light source disposed opposing the one side surface of the light guide plate, and a housing body configured to house the light guide plate and the light source, the light source device comprising:

• a heat transfer unit configured to hold the light guide plate and the light source and transfer heat generated by the light source to a bottom surface of the housing body,
• wherein the heat transfer unit has a plate part which is interposed between the rear surface of the light guide plate and the bottom surface of the housing body,
• the heat transfer unit is adhered to the light guide plate by the plate part by a double-sided tape interposed between the light guide plate and the plate part,
• the heat transfer unit is configured to slide on the bottom surface of the housing body in a facing direction in which the one side surface of the light guide plate and the light source face each other, the heat transfer unit is configured to be prevented from being separated from the bottom surface of the housing body and includes a long hole formed in the plate part with the facing direction as a major axis direction, and an engaging pin which is penetrated through the long hole of the plate part, and has one end which is fixed to the bottom surface of the housing body and the other end which is provided with a head portion having a larger diameter than a minor axis of the long hole.