Patent attributes
According to an embodiment, a distance measuring device includes a light source, a reflection device, a first photodetector and a calculation unit. The reflection device includes a reflection surface configured to scan an object to be measured with light by reflecting the light, and configured to reflect scattered light of the light scattered on the object to be measured. The first photodetector detects the scattered light. The calculation unit calculates a distance from the reflection surface to each of positions on the object to be measured based on a detection result of the first photodetector. The first photodetector includes a photoelectric conversion element including a plurality of detection regions each having different detection sensitivity of the light. The detection regions are arranged in order according to an incident position of the scattered light from the object to be measured at each of positions having the different distance.