The first line and the plurality of second lines are formed on the light-emitting diode substrate and on the connection substrate. The plurality of second lines are arranged, on the connection substrate, in the same direction as a direction in which the plurality of light-emitting diodes mounted on the light-emitting diode substrate are arranged. The first line is formed outside the plurality of second lines, on the connection substrate. The plurality of second lines are formed without intersecting with one another, on the light-emitting diode substrate. The first line is formed, on the light-emitting diode substrate, so that the first line extends along with a periphery of the light-emitting diode substrate from a connection part with respect to the connection substrate so as to come around to an opposite side of the connection part with respect to the connection substrate.