Light source device and projection apparatus

Alight source device comprising:

• a first light source section including one or more first light emitters to emit first light;
• a second light source section including one or more second light emitters to emit second light;
• a light-transmissive member having a central axis to transmit the first light and the second light therethrough to emit the first light and the second light from the light-transmissive member;
• and
• circuitry configured to:
• cause the one or more first light emitters to individually reduce first amount of the first light and cause the one or more second light emitters to individually reduce second amount of the second light;
• or
• individually turn off the one or more first light emitters and the one or more second light emitters;
• and
• alternately switchable, at a switching cycle, between:
• a first state where both the first light and the second light enter the light-transmissive member at a positive angle relative to the central axis of the light-transmissive member in a view in a direction orthogonal to the central axis of the light-transmissive member;
• and
• a second state where both the first light and the second light enter the light-transmissive member at a negative angle relative to the central axis of the light-transmissive member in the view in the direction orthogonal to the central axis.