Patent ID: 8976159
Filing Date: 2015-03-10
Classification: G06F

Abstract:
1. A variable size sensing system comprising: a first element; a second element; a third element; a fourth element, the first, second, third and fourth elements being consecutively connected and thereby forming a first frame, the first element and the third element being capable of increasing their lengths in a predetermined direction so that the size of the first frame can be adjusted and forms a second frame, the inner edge of the first frame defining a sensing area that has a parallelogram shape, surfaces of the second, the third and the fourth elements facing the sensing area being applied with a reflective material; at least one image sensing device configured for sensing images reflected by the second and third elements; and a mark disposed on a surface of the third element facing the sensing area and apart from the fourth element by a fixed distance that equals to the length of the first element; wherein the image sensing device is capable of sensing a location of the mark, so that the change in the length of the third element can be calculated based on the fixed distance and the location of the mark in the images reflected by the second and third elements.