| 摘要 |
Position sensing apparatus comprising two coil arrangements (10, 11) movable relative to each other, the first arrangement (11) being a side-by-side array of elongate coils defining a writing area (21) and the second coil arrangement (10) being a single or multiple coil loose coupled with the coils in the array. The coils in the side-by-side array have phase-shifting units (12) between them so that they give an output which is unambiguously phase-characterised dependent upon the position of the second coil arrangement on the writing area in the direction of the array. Two layers (11, 11,) of the elongate coils can be provided so that the coils in one layer are at right angles to those in the other to give "x" or "y" co-ordinate positioning. The phase shift over the writing area may be less than 360 DEG , or greater than 360 DEG with the use of an ambiguity eliminating circuit. The second coil arrangement (10) may comprise two coils (10A, 10B) carried on a pen (30) and spaced from the pen tip and connected so that indefiniteness does not arise as the pen is tilted. Apparatus according to the invention may have its output processed for line transmission for stock ordering and accounting purposes or for signature verification. |
