Abstract: A night vision device with distance measurement function is configured to obtain a distance between a target object and the night vision device with distance measurement function by inputting a size of the target object and by using a focal length of an objective lens unit, a pixel information of an image sensing module, and a resolution of a display unit. In this way, a simple, fast and inexpensive distance measurement can be achieved without the conventional laser rangefinder.

Abstract: A night-viewing device for use in an environment lacking light source, comprising a first image capturing module, a second image capturing module, a first light source illumination module and a second light source illumination module. The focal ranges of both image capturing modules are different. Meanwhile, the light output angles of both light source illumination modules are also different. When one of the image capturing modules is activated, a control module may select, in accordance with the change of the focal range of both image capturing modules, one of the light source illumination modules whose light output angle is greater than the focal range to drive it in operation such that the generated infrared light may cover the current focal range. In this way, when in observation at a large angle, it can effectively prevent the problem of the excessive darkness around the image capturing angle.