| 摘要 |
PROBLEM TO BE SOLVED: To appropriately reduce distance error without increasing light emission power, using an optical filter, increasing the number of times of integration, or increasing a modulation frequency.SOLUTION: Making use of a phenomenon that, when a duty cycle of a light emission waveform is reduced to below 50%, high order harmonic component energy increases as decreasing duty cycle, a time-of-flight optical ranging device 1 is configured to: reduce the duty cycle of the light emission waveform to below 50%; control exposure of a photosensitive element 6 to have sensitivity for predetermined high-order harmonics; and linearly combine a fundamental wave component and high-order harmonic component. Since the high-order harmonic component is taken into account, distance error is appropriately reduced compared with distance calculation involving just the fundamental wave component.SELECTED DRAWING: Figure 1 |
