| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method for a pupil detection light source apparatus, capable of keeping a pupil's brightness constant by coping with a variation in distance between a subject and a light source when the distance between the subject and the light source has varied.SOLUTION: A control method for a light source comprising a first light-emitting element for making a subject's pupil be bright and a second light-emitting element for making the subject's pupil be dark in comparison with the case that the first light-emitting element is used includes: a step S1 of supplying pulse current to the first light-emitting element while acquiring a bright pupil image; a step S2 of supplying pulse current to the second light-emitting element while acquiring a dark pupil image; a step S3 of calculating a difference image; a step S4 of acquiring a pupil brightness level from the difference image; a step S5 of multiplying the light source's light emission amount by a value obtained by dividing a pupil brightness level target value by the acquired pupil brightness level to determine the light source 3's light emission amount at the time of the next image acquisition; and a step S6 of supplying pulse current for making the light source emit light with the determined light emission amount, to the light source.SELECTED DRAWING: Figure 4 |
