Scanning signal balancing circuit
First Claim
1. In a digital position measuring system of the type comprising a measuring scale, a scanning unit including at least one scanning element positioned to scan the scale and to generate in response thereto a scanning signal, and an evaluating circuit coupled to the at least one scanning element to evaluate the scanning signal, the improvement comprising:
- a balancing circuit coupled to the measuring system and comprising;
at least one bridge circuit; and
at least one balancing element for balancing at least one signal parameter of the scanning signal, said balancing element included in the bridge circuit;
said bridge circuit defining a first pair of diagonal nodes circuited parallel to the at least one scanning element in the scanning unit.
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Accused Products
Abstract
A digital electric length or angle measuring system includes a scanning unit for scanning a measuring scale and an evaluating circuit for evaluating scanning units generated by a plurality of scanning elements of the scanning unit. The scanning elements are connected to differential amplifiers included in the evaluating circuit. In order to balance faulty signal parameters of the scanning signals of the scanning elements, a balancing circuit is provided which includes bridge circuits. In each case, one diagonal of the bridge circuit is circuited in parallel to the scanning elements in the scanning unit and is connected to the inputs of the differential amplifier of the evaluating arrangement. Furthermore, each of the bridge circuits includes at least one balancing element such as a photosensor.
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Citations
13 Claims
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1. In a digital position measuring system of the type comprising a measuring scale, a scanning unit including at least one scanning element positioned to scan the scale and to generate in response thereto a scanning signal, and an evaluating circuit coupled to the at least one scanning element to evaluate the scanning signal, the improvement comprising:
a balancing circuit coupled to the measuring system and comprising; at least one bridge circuit; and at least one balancing element for balancing at least one signal parameter of the scanning signal, said balancing element included in the bridge circuit; said bridge circuit defining a first pair of diagonal nodes circuited parallel to the at least one scanning element in the scanning unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a digital position measuring system of the type comprising a measuring scale, a scanning unit including at least one scanning element positioned to scan the scale and to generate in response thereto a scanning signal, and an evaluating circuit coupled to the at least one scanning element to evaluate the scanning signal, the improvement comprising:
means for balancing at least one signal parameter, of the scanning signal, said balancing means comprising; a four node bridge circuit; means for connecting a first pair of diagonal nodes of the bridge circuit in parallel with the at least one scanning element; and at least one balancing element included in the bridge circuit, said balancing element operative to generate a balancing signal which is applied to the bridge circuit to correct the at least one signal parameter. - View Dependent Claims (12, 13)
Specification