DEVICE FOR IMPARTING DISTANCE INFORMATION

摘要

A device (40) for imparting distance information to a human subject, comprising a hand-holdable housing (42) having a front end (44) and an axis (46), configured so when said housing (42) is held in a human hand with said front end (44) forwards, said axis (46) points straight ahead; physically associated with said housing (42), a light-source (24) configured for projecting a beam of light through a light- source aperture (28) in a direction not more than 4° divergent from parallel to said axis (46); physically associated with said housing (42), a light - detector (26) configured to detect light projected by said light-source (24), reflected from a reflecting object located at a distance from said front end (44) between a minimum distance and a maximum distance and entering through a light - detector aperture (30), at a frame rate where a detection location of said light reflected from a reflecting object on an epipolar line of said light - detector (26) is dependent on said distance to the reflecting object; and functionally associated with said light - detector (26), a distance reporter (56, 68) configured to produce a signal perceptible to a human subject, said perceptible signal modulated as a function of said detection location at a reporting rate; wherein said light-source aperture (28) and said light - detector aperture (30) are separated by an inter- aperture separation of not more than about 5 cm, wherein along said epipolar line between said detection location of light reflected from a reflecting object at said minimum distance and said detection location of light reflected from a reflecting object at said maximum distance there are at least about 20 distinct detection locations, and wherein said perceptible signal is modulated differently for each of said at least about 20 distinct detection locations.