ELECTRONIC DEVICE AND HAVING DISPLAY DEVICE, CONTROL DEVICE

The present invention provides an electronic device, capable of improving utilization efficiency of light by efficiently putting light, emitted from a light source unit, into a light guide plate, and a display apparatus and a control device having the same. A temperature controller (10) includes: a control substrate (21); LEDs (22); a reflective sheet (23); and a light guide plate (24). The LEDs (22a, 22b) are installed on the control substrate (21) and emit light to the surface of the control substrate (21) in a direction parallel to the surface. The reflective sheet (23) is installed in a location close to the LEDs (22a, 22b) on the control substrate (21) at a predetermined interval and reflects light in a direction crossing the control substrate (21). The light guide plate (24) is arranged on the reflective sheet (23) and has a protrusion unit (25) protruding into a gap between a cross section of a light emitting side and a cross section of the reflective sheet (23) on the opposite side thereof, on the LEDs (22a, 22b). The light guide plate (24) absorbs the light emitted from the LEDs (22a, 22b) from a side surface (24a) including the protrusion unit (25), and surface-emits the light from a front surface (24b).