| 摘要 |
PCT No. PCT/GB92/00221 Sec. 371 Date Aug. 10, 1993 Sec. 102(e) Date Aug. 10, 1993 PCT Filed Feb. 6, 1992.The sensor comprises a structured light source (5, 6, 7) which is adjustable so as to interchange the positions of contrasting areas of the pattern it provides, a detector (1) which comprises an array of detector elements having dimensions matched to the pattern produced by the light source, an optical system (2, 8) for projecting a primary image of the light source pattern onto an object (3) that is to be sensed and for forming a secondary image on the detector (1) of the primary image thus formed on the object (3), positioning means (4) for moving at least part (2) of the optical system so as to vary the focussing of the primary image on the object (3) and processing means (12) for analyzing signals produced by the detector (1) in conjunction with information on the adjustment of the optical system (2, 8). The optical arrangement is 'confocal' so that, when the primary image is in focus on the object (3), the secondary image on the detector (1) is also in focus. The processing means (12) is arranged to analyse the images received by the detector (1) with the contrasting areas thereof in the interchanged positions to determine which parts of the images are in focus and hence determine the range of the corresponding parts of the object being viewed. |
