US3591842A - Grid with graduation markings succeeding in nonequidistant spaces relative to each other - Google Patents

Grid with graduation markings succeeding in nonequidistant spaces relative to each other Download PDF

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US3591842A
US3591842A US665009A US3591842DA US3591842A US 3591842 A US3591842 A US 3591842A US 665009 A US665009 A US 665009A US 3591842D A US3591842D A US 3591842DA US 3591842 A US3591842 A US 3591842A
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graduation
markings
grid
cycle
succeeding
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Gerhard Seewald
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Firma Wenczler and Heidenhain
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/36—Forming the light into pulses
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B3/00—Measuring instruments characterised by the use of mechanical techniques
    • G01B3/002—Details
    • G01B3/004—Scales; Graduations

Definitions

  • the present invention relates to a grid with graduation markings succeeding in unequal or nonequidistant spaces relative to each other in general, and to such graduations, which have equal GlAs of the division markings.
  • This section is to be called below the sensing visual field, following the special case of the optically perceptive graduations. It is to be understoodthat it is desired to obtain a possibly high signal or a high signal variation already from a very small sensing visual field, in addition, however, to maintain, as much as possible, constantly small the disturbance signal, that is the signal outside of the preferred range, whereby mostly also the expansion of the mentioned preferred range in relation to the remaining displacement path should be maintained as small as possible.
  • the individual requirements contradict each other to a great extent, for which reason the solutions obtained until now did not bring about sufficient results for all applications.
  • the smallest distance between two graduation markings amounts to one unit and one can make wide, for instance, in optically perceptive graduations, the ranges constituting the individual graduation markings and contrasting relative to their surroundings up to the width of a complete unit. In this case the graduation markings engage each other with the distance I and at this point apparently a double or multiple as wide graduation marking is created.
  • FIGS. 1 and 2 are examples of cycles in accordance with the present invention.
  • FIG. 3 is an example of two superposed grids each corresponding to the cycle of FIG. 2 in a periodically repeating arrangement
  • FIG. 4 is an example of two superposed grids each corresponding to the cycle of FIG. I in a nonperiodic arrangement
  • FIGS. 5 and 6 are further examples ofcycles
  • FIGS. 7 and 8 are examples of superposed grids corresponding to the cycles of FIGS. 5 and 6, respectively, each in a nonperiodic arrangement;
  • n is the number of the division markings and k is frequency of the appearance of any selected interval.
  • P means the number of the smallest units which a cycle contains.
  • the period length P is given in multiples of its smallest unit.
  • the graduation markings are the slotlike elements illustrated in the figures. The symbols a and b appear within the same elements since they indicate two different markings which engage with their edges straight, so that they appear as single markings of their double width. In this case, the graduation markings engage each other with the distance 1 and at this point apparently a double or multiple wide graduation marking is created.
  • FIG. 1 is a diagrammatic representation of FIG. 1:
  • the division markings of lengthor circular-graduations are arranged such, that the centerline of the graduation markings succeed each other in distances, which correspond with such cycle of n graduation markings, which has the period length of .units and in which each full numbered multiple of a .unit appears as distance between two graduation rnarkings exactly k .times.
  • the entire graduation can comprise thereby afull numing point it could be assumed, that this fraction comprises at least (P-l /2 units and contains more than 2n/3 graduation characteristics.
  • FIGS. 3 and 4 show such examples.
  • FIG. 3 two superposed sliding graduations are shown in succeeding displacement steps.
  • the centerlines of the graduation markings follow in distances to each other, which correspond with those of the cycle of FIG. 2.
  • the section shown in FIG. 3 comprises twice the period length, while the graduations themselves can project selectively far beyond this shown section.
  • the resulting signal curve is applied, along the right image edge of FIG. 3.
  • the free opening amounts to 7 units per period, in the shown section 14 units, outside of the preferred range completely constant 3 units per period, in the shown section, 6 units.
  • FIG. 4 shows one such example, in which only one section of a full period is used. The section is taken from the cycle of FIG. 1.
  • the creating signal curve brings about outside of the preferred range a not completely but approximately constant disturbance signal level.
  • FIGS. 7 and 8 show further examples for graduations, which form a section of cyclic graduations of the art of the present invention.
  • the relative displacement of the graduations and the signal curve are shown only at the edge of the Figures due to their great length. One can easily convince oneself, that the signal curve does not increase any more outside the shown range.
  • L is determining for the dissolution capacity (the larger L, the smaller is the preferred range within which the steep fall of the signal from the top value n to no more the value In takes place, in comparison to the length of the graduation).
  • n/L is determining for the transparency of the graduation, also for the absolute height of the signal.
  • n/m is determining for the ratio usesignal/noise signal (signal to noise ratio)
  • FIG. 9 is shown in connection with the graduations T to T mentioned as examples, how a quantitative evaluation of such graduation can be performed.
  • the graduations in accordance with the present invention are disposed in the space L, n/L and n/m on a curved face, which can be placed by the points T to T indicated by crosses.
  • the area is, of course, not limited to the shown range and is particularly selectively extendable in the direction of rising L.
  • equally valued graduations are disposed on the same face as the latter.
  • Other graduations, which are disposed below this area must be characterized as less good.
  • FIG. 10 shows a simple arrangement with which signals are produced upon relative displacement of the graduations.
  • graduation carriers and 101 made of transparent material are lighted by a device which comprises a lamp 103 and condenser I04.
  • a lens 105 collects the light on a phototransformer l06 which emits an electrical signal to the conduit 107.
  • the desired signal is obtained by the cooperation of the graduation markings 109 and 109' (only shownschematically).
  • the graduations can, however, deviating from the example i of FIG. 10, also be sensed photoelectrically, for instance magnetically, capacitively or inductively.
  • the markings of the present invention may, for example, be
  • a grid system comprising a first grid with graduation markings of equal width relative to each other and succeeding one another in nonequidistant spacings and a second grid photoelectrically or optically cooperating scanningly with said first grid and adapted to produce a signal during their relative displacement,
  • said cycle having a period length of units and each full numbered multiple of a unit occurring as spacing between any two of said graduation markings exactly k times, n and k being integral number satisfying the relationship n23 and ngl ,respectively.

Abstract

A grid with graduation-markings of equal width relative to each other and succeeding in nonequidistant spacings, wherein the graduation-markings define center lines which follow each other in distances corresponding with a cycle of n graduation markings. The cycle has a period length of UNITS AND WHEREIN EACH FULL NUMBERED MULTIPLE OF A UNIT OCCURS AS SPACING BETWEEN TWO GRADUATION MARKINGS EXACTLY K TIMES.

Description

United States Patent inventors Appl. No. Filed Patented Asslgnee Priority GRID WITH GRADUATION MARKINGS SUCCEEDING IN NONEQUIDISTANT SPACES Primary Examiner-John Kominski Assistant Examiner-V. LaFranchi Attorney-Ernest G. Montague ABSTRACT: A grid with graduation-markings of equal width relative to each other and succeeding in nonequidistant spacings, wherein the graduation-markings define center lines which follow each other in distances corresponding with a cycle ofn graduation markings. The cycle has a period length of n(n1) T units and wherein each full numbered multiple ofa unit occurs as spacing between two graduation markings exactly k times.
RELATIVE TO EACH OTHER 6 Claims, 10 Drawing Figs.
U.S. CL]. 250/237, 250/233, 340/347 Int. Cl H0lj 5/16, HOlj 39/l2,GO8c 9/06 no "1 t r PATENIEU JUL 6 IHYI 3,591,842
sum 01UF 10 re I 6 k= 7 [3:3, INVENTOR-v unlt [eay [6 Q BY GERHARD SEEWALD A T TORNE Y,
PATENTEDJUL 6mm 3.591; 842 SHEET UBUF 10 mm/m p GERHARD SEEWALD ATTORNEY.
PATENIEU JUL 6 IIIII GERHARD SEEWAL D ATTORNEY.
PATENTED JUL 6197! 3 591842 SHEET nu 0F 10 PATENTEUJUL 6l97| 3,591,842
SHEET 05 [1F 10 :1 if g, INVENTOR GERHARD SEEWALD uni! {907% BY WW AT TORNEY PATENTEU JUL BIS?! 3.591; 842
SHEET c7 0;" 10
u /0 f 5/ Fig. 7
ll l l' s n l I he I n I ll f; I
IN VI-JN 7'01. GERHARD SEEWALD ATTORNEY.
PATENTEUJUL BIB?! 8,591,842
SHEET 0811f 10 Fig. 8
' INVENTOR GERHARD SEE WALD WLKMX AT TORNEK PATENTED JUL 6 Ian SHEET 09 0F Fig. 9
ATTORNEY.
PATENTED JUL 6 I97! SHEET 10 OF ATTORNEY.
GRID WITH GRADUATION MARKINGS SUCCEEDING IN NONEQUIDISTANT SPACES RELATIVE TO EACH OTHER The present invention relates to a grid with graduation markings succeeding in unequal or nonequidistant spaces relative to each other in general, and to such graduations, which have equal GlAs of the division markings.
Such graduations are known and disclosed, for instance, in
US. Pat. No. 2,406,299, dated Aug. 20, 1946. Such divisions or graduations divisions adapted to deliver a signal during their displacement relative to a second similar or complementary graduation. Such a signal has in the vicinity of a predetermined relative position arrangement of the two divisions or graduations, namely in a preferred range, an appreciably steeper variation of its value than in other position arrangements. Divisions or graduations of this type can be characterized by the feature over what size of displacement path thepreferred range extends, how high the signal and its change, respectively, is arranged in the preferred range, how high these values are in the remaining range, and how large of a section of the two divisions of graduations must cooperate together, in order to obtain the mentioned values. This section is to be called below the sensing visual field, following the special case of the optically perceptive graduations. It is to be understoodthat it is desired to obtain a possibly high signal or a high signal variation already from a very small sensing visual field, in addition, however, to maintain, as much as possible, constantly small the disturbance signal, that is the signal outside of the preferred range, whereby mostly also the expansion of the mentioned preferred range in relation to the remaining displacement path should be maintained as small as possible. The individual requirements contradict each other to a great extent, for which reason the solutions obtained until now did not bring about sufficient results for all applications.
It is one object of the present invention to provide a grid with division markings succeeding in nonequidistant spaces, wherein the drawbacks of the mentioned divisionsor graduations are avoided.
It is another object of the present invention to provide a grid with graduation markings succeeding in nonequidistant spaces, which are based on the surprising finding that it is possible to form cycles of n graduation markings, which have the period length units, and in which each full numbered multiple of a unit appears as distance between two graduation markings exactly k times. The smallest distance between two graduation markings amounts to one unit and one can make wide, for instance, in optically perceptive graduations, the ranges constituting the individual graduation markings and contrasting relative to their surroundings up to the width of a complete unit. In this case the graduation markings engage each other with the distance I and at this point apparently a double or multiple as wide graduation marking is created.
With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:
FIGS. 1 and 2 are examples of cycles in accordance with the present invention;
FIG. 3 is an example of two superposed grids each corresponding to the cycle of FIG. 2 in a periodically repeating arrangement;
FIG. 4 is an example of two superposed grids each corresponding to the cycle of FIG. I in a nonperiodic arrangement;
FIGS. 5 and 6 are further examples ofcycles;
FIGS. 7 and 8 are examples of superposed grids corresponding to the cycles of FIGS. 5 and 6, respectively, each in a nonperiodic arrangement;
multiple part of part of a full cycle if n is the number of the division markings and k is frequency of the appearance of any selected interval. For the individualexamples n, k and the length of. the period P, are given below in form of tables, and furthermore the pairs of division markings which result in a predetermined interval. P means the number of the smallest units which a cycle contains. The period length P is given in multiples of its smallest unit. The graduation markings are the slotlike elements illustrated in the figures. The symbols a and b appear within the same elements since they indicate two different markings which engage with their edges straight, so that they appear as single markings of their double width. In this case, the graduation markings engage each other with the distance 1 and at this point apparently a double or multiple wide graduation marking is created.
FIG. 1:
Interval FIG. 2:
Interval The corresponding tables for the examples of FIGS. 5 and 6 are not particularly stated in order to save space. It can be, however, also simply shown there that within a graduation all graduation intervals appear at equal frequency.
In accordance with the present invention the division markings of lengthor circular-graduations are arranged such, that the centerline of the graduation markings succeed each other in distances, which correspond with such cycle of n graduation markings, which has the period length of .units and in which each full numbered multiple of a .unit appears as distance between two graduation rnarkings exactly k .times. The entire graduation can comprise thereby afull numing point it could be assumed, that this fraction comprises at least (P-l /2 units and contains more than 2n/3 graduation characteristics.
FIGS. 3 and 4 show such examples.
In FIG. 3 two superposed sliding graduations are shown in succeeding displacement steps. The centerlines of the graduation markings follow in distances to each other, which correspond with those of the cycle of FIG. 2. The section shown in FIG. 3 comprises twice the period length, while the graduations themselves can project selectively far beyond this shown section. The resulting signal curve is applied, along the right image edge of FIG. 3. Upon complete overlapping, the free opening amounts to 7 units per period, in the shown section 14 units, outside of the preferred range completely constant 3 units per period, in the shown section, 6 units.
FIG. 4 shows one such example, in which only one section of a full period is used. The section is taken from the cycle of FIG. 1. One recognizes, that the creating signal curve brings about outside of the preferred range a not completely but approximately constant disturbance signal level.
FIGS. 7 and 8 show further examples for graduations, which form a section of cyclic graduations of the art of the present invention. The relative displacement of the graduations and the signal curve are shown only at the edge of the Figures due to their great length. One can easily convince oneself, that the signal curve does not increase any more outside the shown range.
The following table reflects the characteristic values for the nonperiodic examples of FIGS. 1 and 4, FIGS. and 7, and FIGS. 6 and 8:
Nomination Soown in Section 11 m L mL n/m FIG. 6 .l 2 26 0. 346 4,5 FIG. 5 l0 1 56 0.170 FIG. 1 6 1 18 0.333 6 L Length of the graduation (in multiples ofa field width) n Number ofthe open fields m Maximum of the signal curve outside of the preferred range (in multiples ofa field width) For the characterization of the individual graduations (compare FIG. 9).
L is determining for the dissolution capacity (the larger L, the smaller is the preferred range within which the steep fall of the signal from the top value n to no more the value In takes place, in comparison to the length of the graduation).
n/L is determining for the transparency of the graduation, also for the absolute height of the signal.
n/m is determining for the ratio usesignal/noise signal (signal to noise ratio) In FIG. 9 is shown in connection with the graduations T to T mentioned as examples, how a quantitative evaluation of such graduation can be performed. The graduations in accordance with the present invention are disposed in the space L, n/L and n/m on a curved face, which can be placed by the points T to T indicated by crosses. The area is, of course, not limited to the shown range and is particularly selectively extendable in the direction of rising L. With the graduations according to the present invention, equally valued graduations are disposed on the same face as the latter. Other graduations, which are disposed below this area, must be characterized as less good. The curve h/m== is drawn furthermore in FIG. 9, which values of n/L and L with a single slot can be obtained (which of course is part of the status of the prior art). For the individual slot a ratio n/m== can be obtained. The present invention aims to obtain with values of L and n/L. which deviate from the shown curve nlm=== to achieve as much as possible high values of-nlm, all. and L.
FIG. 10 shows a simple arrangement with which signals are produced upon relative displacement of the graduations. The
graduation carriers and 101 made of transparent material are lighted by a device which comprises a lamp 103 and condenser I04. A lens 105 collects the light on a phototransformer l06 which emits an electrical signal to the conduit 107. Upon movement of the graduation carrier 100 and 101 in the direction of the arrow 108, the desired signal is obtained by the cooperation of the graduation markings 109 and 109' (only shownschematically).
The graduations can, however, deviating from the example i of FIG. 10, also be sensed photoelectrically, for instance magnetically, capacitively or inductively.
Also a plain optically visual observation is possible. In this case advantageously periodic graduations are used. By the absolutely equal gray value between. the signal tops, a reading possibility very safe for the eye results, when the narrow signal points find use as optical fine indicator or similar element.
The markings of the present invention may, for example, be
used in the device of U.S. Pat. No. 2,406,299 instead of the units and each full numbered multiple ofa unit occurring as spacing between any two of said graduation markings exactly k times, n and k being integral numbers satisfying the relationship 3 and 5 respectively.
2. The grid, as set forth in claim 1, wherein said individual graduation-markings comprise ranges, contrasting relative to their surrounding, of a width at the most of one unit.
3. The grid, as set forth in claim 1, wherein the total graduation comprises a full numbered multiple of the period length.
4. The grid, as set forth in claim 1, wherein the total graduation comprises a nonfull numbered multiple of the period length.
5. The grid, as set forth in claim 1, wherein the total graduation comprises a fraction of a full period extending over at least Pl )/2 units and containing more than 2n/3 graduation characteristics.
6. A grid system comprising a first grid with graduation markings of equal width relative to each other and succeeding one another in nonequidistant spacings and a second grid photoelectrically or optically cooperating scanningly with said first grid and adapted to produce a signal during their relative displacement,
said graduation markings defining centerlines,
said centerlines of such graduation markings following each other in spaced distances corresponding with a cycle of n graduation markings, and
said cycle having a period length of units and each full numbered multiple of a unit occurring as spacing between any two of said graduation markings exactly k times, n and k being integral number satisfying the relationship n23 and ngl ,respectively.

Claims (6)

1. A grid with graduation-markings of equal width relative to each other and succeeding one another in nonequidistant spacings, said graduation-markings defining centerlines, said centerlines of such graduation-markings following each other in spaced distances corresponding with a cycle of n graduation markings, and said cycle having a period length of units and each full numbered multiple of a unit occurring as spacing between any two of said graduation markings exactly k times, n and k being integral numbers satisfying the relationship n 3 and 1 k (n-1)/2, respectively.
2. The grid, as set forth in claim 1, wherein said individual graduation-markings comprise ranges, contrasting relative to their surrounding, of a width at the most of one unit.
3. The grid, as set forth in claim 1, wherein the total graduation comprises a full numbered multiple of the period length.
4. The grid, as set forth in claim 1, wherein the total graduation comprises a nonfull numbered multiple of the period length.
5. The grid, as set forth in claim 1, wherein the total graduation comprises a fraction of a full period extending over at least P-1)/2 units and containing more than 2n/3 graduation characteristics.
6. A grid system comprising a first grid with graduation markings of equal width relative to each other and succeeding one another in nonequidistant spacings and a second grid photoelectrically or optically cooperating scanningly with said first grid and adapted to produce a signal during their relative displacement, said graduation markings defining centerlines, said centerlines of such graduation markings following each other in spaced distances corresponding with a cycle of n graduation markings, and said cycle having a period length of units and each full numbered Multiple of a unit occurring as spacing between any two of said graduation markings exactly k times, n and k being integral number satisfying the relationship n 3 and l k (n-1)/2, respectively.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4716534A (en) * 1984-10-31 1987-12-29 Baucom D Michael Microprocessor based level and angle finder
US4827249A (en) * 1984-06-29 1989-05-02 Texas Instruments Incorporated Video system with combined text and graphics frame memory
US4988865A (en) * 1988-03-22 1991-01-29 Frankl & Kirchner Gmbh & Co Kg Fabrik Fur Elektromotoren U. Elektrische Apparate Device for determining the angular position of the drive shaft in a sewing machine
US20090041479A1 (en) * 2005-07-21 2009-02-12 Jeon Jun-Bae Image forming apparatus and method of detecting home position error

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187187A (en) * 1962-01-24 1965-06-01 Wayne George Corp Photoelectric shaft angle encoder

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187187A (en) * 1962-01-24 1965-06-01 Wayne George Corp Photoelectric shaft angle encoder

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4827249A (en) * 1984-06-29 1989-05-02 Texas Instruments Incorporated Video system with combined text and graphics frame memory
US4716534A (en) * 1984-10-31 1987-12-29 Baucom D Michael Microprocessor based level and angle finder
US4988865A (en) * 1988-03-22 1991-01-29 Frankl & Kirchner Gmbh & Co Kg Fabrik Fur Elektromotoren U. Elektrische Apparate Device for determining the angular position of the drive shaft in a sewing machine
US20090041479A1 (en) * 2005-07-21 2009-02-12 Jeon Jun-Bae Image forming apparatus and method of detecting home position error

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