VISIBLE LIGHT RECEPTION DEVICE AND VISIBLE LIGHT RECEPTION METHOD

A receiving device (10) includes a first conversion unit (11), an amplification unit (12), and a microcomputer (13). The microcomputer (13) includes: a second conversion unit (14) that performs, for each sampling time duration, AD conversion on a voltage signal into an AD-converted value; a first calculation unit (15) that calculates a difference digital value by difference calculation; a second calculation unit (16) that calculates a positive reference value and a negative reference value; a detection unit (17) that detects a rising point starting difference digital values greater than the positive reference value, and a falling point starting difference digital values smaller than the negative reference value; a third calculation unit (18) that calculates a first sample period and a second sample period; and a fourth calculation unit (19) that calculates a modulated signal for each symbol time period based on the first sample period and the second sample period.