초록 ▼

Apparatus for evaluating signals generated by first and second spatially separated rows of photoconductors positioned with respect to a measuring plane. The outputs of the photoconductors in each of the rows is scanned by a sampling circuit at a predetermined rate, and the outputs of each sampling c

Apparatus for evaluating signals generated by first and second spatially separated rows of photoconductors positioned with respect to a measuring plane. The outputs of the photoconductors in each of the rows is scanned by a sampling circuit at a predetermined rate, and the outputs of each sampling circuit coupled to at least one evaluation circuit. Each of the evaluation circuits includes an analog-to-digital converter coupled to the output of the associated sampling circuit, and a pair of digital delay circuits having their inputs alternately coupled to the output of the A/D converter. A comparator is provided for comparing a threshold signal generated by a reference generator with the outputs of the digital delay circuits, the comparator generating a digital signal having a value corresponding to the difference between the ratio of the signals at the outputs of the delay circuits and the threshold signal. A computer coupled to the outputs of the comparators in each of the evaluation circuits determines the coordinates of an object traversing the measuring plane.

대표청구항 ▼

In a device for determining the point of passage of a moving object through a measuring plane, the device including (1) two mutually inclined cameras arranged at a distance from one another, each being provided with a row of n photodetectors which are scanned successively in a fast rhythm to provide

In a device for determining the point of passage of a moving object through a measuring plane, the device including (1) two mutually inclined cameras arranged at a distance from one another, each being provided with a row of n photodetectors which are scanned successively in a fast rhythm to provide sampled signals from each row of photodetectors; (2) an evaluation circuit including two portions to which are fed the sampled signals from a respective row of photodetectors, each portion of the evaluation circuit including a delay device for delaying the signals derived from the n photodetectors of the respective row as well as a comparison circuit which compares output signals derived from the same photodetectors but offset in time and emits a 0 or 1 signal depending on the difference between the signals; and (3) a computer which receives the output signals from the comparison circuit of both portions of the evaluation circuit for determining the coordinates of the point of passage, the improvement wherein: each portion of the evaluation circuit includes at its input an analog/digital converter; the delay devices comprise digital double memories in which are stored those signals which are derived from the signals of the respective photodetector rows during the last two sampling cycles; and the comparison circuits receive the signal just derived from a photodetector and the corresponding signal derived two sampling cycles earlier, said comparison circuits forming the quotients of these signals and comparing them with a threshold value.