A jitter measurement method using a down-mixing or down-converting topology in a jitter measurement system preserves the jitter UI rather than the jitter seconds. Content which includes a content body and rights information indicating a use condition given to the content body is acquired. Suitable chromophore components generally fluoresce blue, red, violet, or purple color when exposed to ultraviolet light, or they may absorb light to reflect these same shades. The guiding tilt surface extends toward a direction of protruding the light-emitting surface.