Abstract: A measuring system is described which includes a scale which defines a measuring graduation and an array of reference marks. The reference marks are positioned at predetermined absolute positions with respect to the graduation and are used to generate reproduceable electric reference control pulses. In order to identify each of the reference marks a serially allocated code mark is provided which is made up of at least one nonzero code mark segment. Each nonzero code mark segment agrees in spatial pattern with the nonzero associated reference mark in the measuring direction. In order to distinguish nonzero code mark segments from reference marks, the width of the nonzero code mark segments perpendicular to the measuring direction is made less than the width of the reference marks.

Abstract: A measuring system includes reference marks provided in the measuring direction alongside the graduation of the scale. These reference marks are absolutely allocated to the graduation and are used to generate reproduceable control pulses. For the identification of each reference mark there is serially allocated to each reference mark a code mark which is made up of code mark segments. The code mark segments follow one upon the other without gaps in the measuring direction, and each includes a homogeneously continuous surface or zone. These code mark segments are arranged in correspondence to their coded information, offset parallel to one another transversely to the measuring direction and are scanned by a scanning field which is integrated in the scanning field used to scan the reference marks. This gapless arrangement of the code mark segments prevents interference with the scanning of the reference marks.

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.

Abstract: A digital electronic length or angle measuring instrument includes an arrangement for error correction. A signal generator delivers periodic analog reference signals R.sub.S1, R.sub.S2 which are compared in a comparator with scanning signals S.sub.1, S.sub.2 generated by the measuring instrument. In accordance with the result of the comparison in the comparator, the reference signals R.sub.S1, R.sub.S2 are altered as a function of correction data for symmetry, amplitude ratio, phase angle, and signal form, which correction data are determined in a correction component and are supplied to setting members included in the signal generator. In this way, an in dependence on the correction data, improved reference signals are generated which then form a basis for the next comparison in the comparator.

Abstract: An incremental length measuring instrument generates analog scanning signals S.sub.1, S.sub.2 with a certain period P which are applied to a comparator in conjunction with two reference signals R.sub.S1, R.sub.S2. The measuring instrument causes the scanning signals S.sub.1, S.sub.2 to change as a function of relative displacement to two components of the measuring instrument. The comparator generates an analog control signal S.sub.D as a function of the difference of the momentary values of the signals applied as inputs to the comparator. The analog control signal S.sub.D is applied as an input to a signal generator which includes an oscillator. The oscillator generates a number of pulses in dependence on the momentary value of the analog control signal S.sub.D. These pulses cause the reference signals R.sub.S1, R.sub.S2 to be modified by the signal generator. In addition, the pulses are fed in a direction dependent manner into an incremental counter which includes a numerical display.

Abstract: A speed monitoring circuit is disclosed for an automatic positioning system. This speed monitoring circuit composes a measurement of the actually present speed determined from measurement signals generated by an incremental position measuring device with the desired speed commanded by the positioning system. The difference between the actual and commanded speed is detected and, in the event of an excessive deviation, a warning or an automatic termination of operation of the positioning system is provided. In the disclosed system, the desired speed is determined by a controller in which a digital computer calculates the difference between the instantaneous position of one relatively movable machine component and the desired position of the movable component as established by programmed data.

Abstract: An incremental path measuring instrument is disclosed which includes a plurality of reference marks R.sub.1 . . . R.sub.n which are interposed between respective code marks C.sub.1 . . . C.sub.n. The reference marks and code marks are applied alternately and serially to the reference track included on the measuring scale. A scanning unit is included in the measuring device for scanning in series the reference marks and the code marks. Each of the code marks is unique, and only one of the two adjacent code marks and the respective reference mark must be scanned by the scanning unit in order to identify the reference mark unambiguously. When absolute position values are allocated to respective individual reference marks, the incremental path measuring device can operate in a quasi-absolute mode of operation, since then the position of each of the reference marks is established with respect to a predetermined zero point.

Abstract: A measuring system for measuring the relative position of two objects, which includes a transducer for converting a mechanical input into an analog electrical signal, is provided with a trigger stage and a reference signal stage. An analog electrical signal generated by the transducer is applied to one input of the trigger stage and to the input of the reference signal stage. The reference signal stage operates to generate a reference signal which is dependent upon the analog signal and is applied to the second input of the trigger stage. The trigger stage generates a trigger signal at its output in response to a change in the analog signal resulting from a change in the mechanical input magnitude.

Abstract: An improved apparatus for powering electrical components in an absolute position measuring device of the type including a coded scale and a scanning unit for reading the coded scale, wherein the scanning unit contains a code generator having a plurality of electrical components such as light-emitting diodes. The disclosed apparatus includes a capacitor connected in parallel with the components and a switching element, such as a transistor, connected in series with the components and in parallel with the capacitor. The switching element is responsive to a switching pulse of defined duration and voltage and it selectively applies a supply voltage to and interrupts the supply voltage from the electrical components.

Abstract: A switching apparatus for an absolute position measuring device of the type including a coded scale and a scanning unit for reading the coded scale, wherein the scanning unit includes a plurality of electrical components. The disclosed switching apparatus includes a capacitor connected in parallel with the electrical components and a switching element, such as a transistor, connected in series with the electrical components and in parallel with the capacitor. The switching element is responsive to a switching signal to selectively apply a supply voltage to and interrupt the supply voltage from the electrical components, all without charging or discharging the capacitor.

Abstract: A digital photoelectric angle or length measuring instrument, of the type having a scale with at least one division, a scanning unit for scanning the division to generate a scanning signal, and an evaluating unit having a trigger circuit for evaluating the scanning signal, is provided with means for generating at least one test signal and means for selectively applying the test signal either to the trigger circuit or to a light source such that the trigger threshold of the trigger circuit is temporarily varied by a selected amount, thereby providing a simple, reliable check of the trigger threshold of the trigger circuit, without requiring external equipment or disassembly of the measuring instrument.

Abstract: A frequency-to-voltage converter for a digital tachometer is disclosed which is responsive to two measured signals generated by a rotational transducer. These two measured signals are applied to a direction discriminator which generates multiple pulse trains in response to the transducer. Each of these pulse trains has a frequency no less than that of the measured signals and the pulse trains are offset with respect to one another in phase angle. Each of the pulse trains is applied to a separate switching circuit which acts to generate a respective sequence of constant energy pulses. These sequences of constant energy pulses are summed in a summation amplifier and passed via a low pass filter to one input of a differential amplifier. The other input of the differential amplifier is coupled to the direction discriminator by a similar sequence of switching circuits, a summation amplifier, and a low pass filter.

Abstract: An improved digital photoelectric position measuring device of the type comprising a scale, a scanning unit for generating scanning signals, and an evaluating circuit for evaluating the scanning signals, wherein the scanning unit includes at least one photoelectric circuit comprising a pair of photosensitive elements for generating counterphase scanning signals, and wherein the evaluating circuit includes at least one pulse forming circuit response to the difference of the counterphase scanning signals. The measuring device includes at least one photosensitive element for generating a direct flux signal and a light source for illuminating the photosensitive element. The direct flux signal is applied to at least one photoelectric circuit in order to balance the pair of photosensitive elements independently of the evaluating unit.

Abstract: A balancing circuit for a digital, photoelectric length or angle measuring system which includes a measuring scale, first and second light sources for illuminating the scale, and photosensitive scanning elements for measuring light modulated by the scale. The disclosed balancing circuit includes a separate balancing branch for each of the light sources. Each balancing branch is separately adjustable, and each balancing branch serves to provide an equal light signal use to compensate for the average intensity of the respective light source. Preferably, only one of the two light sources is activated at any given time, and the two balancing branches are arranged so that the balancing branch associated with the activated light source is not adversely influenced by the balancing branch associated with the non-activated light source.

Abstract: An incremental measuring instrument having a series of fixed reference marks along one edge of the grid scale is disclosed in which a series of movable magnets or occluding screens are located along the opposite edge of the grid scale so that any subset of the total set of reference marks may be designated for control purposes. A scanning unit is provided to scan the scale, and this scanning unit includes a first photosensitive element responsive to the fixed reference marks, and a second photosensitive element mounted in anti-parallel with the first photosensitive element. This second photosensitve element is illuminated by light which varies in intensity according to whether or not the respective reference mark has a magnet or occluding screen associated therewith.

Abstract: A photoelectric circuit is provided with a differential amplifier having two inputs. First and second photosensitive elements and resistors are connected in parallel to each of the two inputs of the differential amplifier, respectively. A second amplifier is provided with its input coupled in parallel to a third resistor and a third photosensitive element. The output of the second amplifier is applied as a bias voltage to each of the three photosensitive elements in parallel.

Abstract: An apparatus for detecting the passage of a moving object such as a truncated stern projectile includes a laser light screen, a photo sensor, and a signal processor. The intensity signal produced by the photo sensor is processed to generate an output pulse at the instant when the first time derivative of the intensity is greatest. For truncated stern projectiles this occurs when the projectile exits the light screen.