Light source device, test system including the same, and operation method thereof

A light source device comprising:

• a plurality of light sources including a first light source configured to radiate a first light toward a chart changer;
• a plurality of neutral-density (ND) filters including a first ND filter attached to the first light source and configured to adjust the first light;
• an aperture unit including a plurality of apertures configured to adjust the first light received from the first ND filter;
• and
• a diffuser configured to diffuse the first light received from the aperture unit and to radiate the first light for testing an image sensor,
• wherein an illuminance of the first light is adjusted based on a transmittance of the first ND filter and an aperture ratio of each aperture of the plurality of apertures,
• wherein, while the first light having a first color temperature is adjusted, a magnitude of a power supplied to the light source device is uniformly maintained,
• wherein the light source device is further configured to be movable in a first direction toward the chart changer or in a second direction opposite to the first direction,
• wherein the illuminance of the first light increases as the light source device moves closer to the chart changer,
• wherein each of the plurality of light sources is rotatable individually,
• wherein the first ND filter is one of the plurality of ND filters, is disposed at a first position where the first light is radiated toward the chart changer,
• wherein the first light source comprises a plurality of portions and is rotatable around a first axis,
• wherein each of the plurality of ND filters is attached to a corresponding one of the portions of the plurality of portions,
• wherein the first light source is further configured to rotate, based on the first control signal, to locate one of the plurality of ND filters at the first position as the first ND filter, and
• wherein each of the plurality of ND filters have a different transmittance.

A method of operating a test system, which includes a light source device radiating a test light toward a chart charger, the method comprising:

• activating a first light source to radiate a first light among a plurality of light sources included in the light source device, based on a target color temperature;
• placing a first neutral-density (ND) filter among a plurality of ND filters attached to the first light source at a first position where the test light is radiated, based on a target illuminance;
• adjusting an aperture ratio of each of a plurality of apertures included in the light source device, based on the target illuminance;
• and
• adjusting a position of the light source device, based on the target illuminance,
• wherein, while the first light source radiates the test light of the target color temperature, a magnitude of a power supplied to the first light source is uniformly maintained,
• wherein the adjusting the position of the light source device comprises moving the light source device in a first direction toward the chart changer or in a second direction opposite to the first direction,
• wherein an illuminance of the test light increases as the light source device moves closer to the chart changer,
• wherein the first light source comprises a plurality of portions,
• wherein each ND filter of the plurality of ND filters has a different transmittance and is respectively attached to one of the portions of the plurality of portions,
• wherein the placing of the first ND filter at the first position where the test light is radiated includes:
• rotating the first light source to align a portion of the first light source to which the first ND filter is attached with the first position, and
• wherein the illuminance of the test light is adjusted based on the transmittance of the first ND filter.