DISTANCE MEASUREMENT DEVICE, HEAD-MOUNTED DISPLAY DEVICE, MOBILE INFORMATION TERMINAL, IMAGE DISPLAY DEVICE, SURROUNDINGS MONITORING SYSTEM, AND DISTANCE MEASUREMENT METHOD

A distance measurement device includes an imaging optical system, an imaging device, and a distance measurement section which measures based on a plurality of images captured by the imaging device, a distance from the imaging device to the target to be imaged. The imaging optical system includes a polarization beam splitting section which splits a first polarization beam having a first polarization direction and a second polarization beam having a second polarization direction substantially orthogonal to the first polarization direction and allows the polarization beam splitting section to be incident on the imaging device. The imaging device receives the first polarization beam to capture a first polarization image and the second polarization beam to capture a second polarization image. The distance measurement section measures the distance to the target to be imaged on the basis of the first polarization image and the second polarization image.