Abstract: A position encoder for monitoring position of an object includes a target pattern, an illumination system, an image sensor, and a control system. The illumination system generates (i) a first illumination beam that is directed toward and impinges on the target pattern, the first illumination beam having a first beam characteristic; and (ii) a second illumination beam that is directed toward and impinges on the target pattern, the second illumination beam having a second beam characteristic that is different than the first beam characteristic. The image sensor is coupled to the object and is spaced apart from the target pattern. The image sensor senses a first set of information from the first illumination beam impinging on the target pattern and senses a second set of information from the second illumination beam impinging on the target pattern. The control system analyzes the first set of information and the second set of information to monitor the position of the object.

Abstract: A measuring device (233) for monitoring movement of a first object relative to a second object, the first object or the second object including a target surface (13), comprises a first image sensor combination (236), a second image sensor combination (237), and a control system (20A). The image sensor combinations (236, 237) capture first images and second images of the target surface (13) over time. The first image sensor combination (236) includes a first image sensor (236A) and a first lens assembly (236B). The second image sensor combination (237) includes a second image sensor (237A), and a second lens assembly (237B) having a second optical axis (237BX) that is at an angle of between thirty degrees and sixty degrees relative to normal to the target surface (13). The control system (20A) analyzes the first images and the second images to monitor movement of the first object relative to the second object.

Abstract: A position encoder for monitoring position of an object includes a target pattern, an illumination system, an image sensor, and a control system. The illumination system generates (i) a first illumination beam that is directed toward and impinges on the target pattern, the first illumination beam having a first beam characteristic; and (ii) a second illumination beam that is directed toward and impinges on the target pattern, the second illumination beam having a second beam characteristic that is different than the first beam characteristic. The image sensor is coupled to the object and is spaced apart from the target pattern. The image sensor senses a first set of information from the first illumination beam impinging on the target pattern and senses a second set of information from the second illumination beam impinging on the target pattern. The control system analyzes the first set of information and the second set of information to monitor the position of the object.

Abstract: A measuring device (233) for monitoring movement of a first object relative to a second object, the first object or the second object including a target surface (13), comprises a first image sensor combination (236), a second image sensor combination (237), and a control system (20A). The image sensor combinations (236, 237) capture first images and second images of the target surface (13) over time. The first image sensor combination (236) includes a first image sensor (236A) and a first lens assembly (236B). The second image sensor combination (237) includes a second image sensor (237A), and a second lens assembly (237B) having a second optical axis (237BX) that is at an angle of between thirty degrees and sixty degrees relative to normal to the target surface (13). The control system (20A) analyzes the first images and the second images to monitor movement of the first object relative to the second object.