| 摘要 |
<p>An optical sensor improved in dynamic range of optical sensing, S/N ratio, and speed. In a photodiode (PDm,n), charge the amount of which depends on the intensity of input light is produced and accumulated in a junction capacitive portion. The charge amount level determining circuit (10m,n) determines the level of the amount of charge accumulated. The capacitance of an integrating capacitive portion (21) of an integrating circuit (20m) is determined according to the result of the charge amount level determination. The charge received from the photodiode (PDm,n) through a switch (SW1m,n) is accumulated in the integrating capacitive portion (21), and a voltage value (V20) depending on the accumulated amount of charge is outputted from the integrating circuit (20m). A voltage value (Vinp) is inputted into a noninverting input terminal of an amplifier (A) of the integrating circuit (20m). The voltage value (Vinp) during the first period of time during which the junction capacitive portion of the photodiode (PDm,n) holds the charge is higher than that during the second period of time during which the integrating capacitive portion (21) of the integrating circuit (20m) holds the charge.</p> |
