Light emitting device array and light source device using the same

A light source device, comprising:

• a plurality of LED strings connected in parallel, each LED string including a plurality of light emitting devices connected in series,
• wherein each of the plurality of LED strings includes an impedance controlling pattern electrically connected to a corresponding plurality of light emitting devices, and is configured such that a level of a forward voltage applied to the corresponding plurality of light emitting devices included in at least one LED string among the plurality of LED strings is lower than a level of a forward voltage applied to the corresponding plurality of light emitting devices included in a different LED string, and the at least one LED string includes an impedance controlling pattern, different from an impedance controlling pattern of the different LED string and connected to the corresponding plurality of light emitting devices in series, and the impedance controlling pattern included in the at least one LED string is configured to compensate for a difference in forward voltage levels applied to the at least one LED string and to the different LED string.

A light emitting device array, comprising:

• a first light emitting diode (LED) string connected in parallel with a second LED string, each of the first and second LED strings including a plurality of light emitting devices connected in series,
• a voltage compensation unit connected in series to one of opposing ends of the plurality of light emitting devices included in the first LED string,
• wherein a sum of forward voltages (Vf) of the plurality of light emitting devices included in first LED string is less than a sum of forward voltages of the plurality of light emitting devices included in the second LED string, and the voltage compensation unit is configured to compensate for a difference in forward voltage levels between the first LED string and the second LED string.