| 摘要 |
The invention relates to the simple and low-cost production of an electronic measuring tape ( 10 ) comprising an external housing ( 12 ) provided with a tape exit opening ( 14 ), a tape winding-up device ( 20 ), a tape ( 30 ) which is wound up in the tape winding-up device ( 20 ) and is withdrawable from the external housing ( 12 ) through the tape exit opening ( 14 ), wherein said tape is provided with first and second surfaces. A radiation source ( 50 ) is arranged between the tape exit opening ( 14 ) and the tape winding-up device ( 20 ) for sending a beam to the first surface of the tape ( 30 ). A detecting device ( 60 ) is placed at the side of the second surface of the tape ( 30 ) for receiving the beam and transmitting data representing the received radiation to an evaluation device ( 70 ) for determining, from these data, the length of the tape ( 30 ) extracted through the tape exit opening ( 14 ). According to said invention, the tape ( 30 ) is radiation-permeable and provided with a biunique code ( 40 ) on one of the two surfaces thereof. Said code represents the length of the tape ( 30 ) extracted through the tape exit opening ( 14 ) and consists of elements influencing the radiation-transmitting capacity of the tape ( 30 ). Said invention also relates to an electronic length-measuring device provided with display and evaluation means for determining a length according to received data and for generating visual data according to said length on the display means, wherein said measuring tape ( 10 ) is connected to the evaluation unit.
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