A projector for selectively projecting patterns of light onto a remote object, one use of which is in conjunction with a system to establish measurements of the surface characteristics of the object, the projector including at least one light source and associated lens assembly mounted to project light onto the remote object, and a rotatable mask member having two or more segments, each segment a distinctive optical pattern, which mask can be rotated as to position a selected one of the segments between the light source and the projection lens assembly whereby when light is directed through the selected segment the light projected onto the remote object will be modified by the optical pattern on that segment. The projector may have two or more spaced light sources and associated projection lens assemblies, and the mark rotatable therebetween to produce distinctively different patterns of light impinging on the remote object when the respective light sources are illuminated, the patterns of light projected on the object when a selected mask segment is positioned in the path of one of the light sources when it is illuminated being angularly related to the pattern of images projected on the object when that same segment is positioned between a second light source and second lens and that second light source is illuminated.

A method for measuring a three-dimensional position of an object with a single camera and a multislit light, i.e., a source of multiplanar light beams. A surface of the object is irradiated with multislit lights, i.e., multiplanar light beams, having a plurality of slit light faces and also irradiated with a single standard slit light having a slit light face identical to one of the plurality of slit light faces of the multislit lights. A plurality of slit light photo images corresponding to a plurality of slit light projected images and a standard slit light photo image corresponding to a slit light projected image formed on the object are obtained. One of the slit light photo images which corresponds to the standard slit light photo image is specified and made to correspond, to compute a three-dimensional position of the object in a predetermined coordinate.

An interactive display system includes a pixel-based display surface and a light pen. A sequence of patterns is projected onto the display surface. The sequence of patterns has a unique sequence of light intensities for each location of the display surface. Intensities of light at an arbitrary location are sensed by the light pen while projecting the sequence of patterns. The intensifies of light are decoded to determine coordinates of the arbitrary location.

The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.

A system for producing data to represent the three-dimensional shape of a surface including a projector for projecting patterns onto the surface. A sensor for producing representations of selected imaged patterns as projected onto the surface, and a device containing data that represents the relative positions of the projector and the sensor for processing data produced by sensor to generate output data that is representative of the shape of the surface.