Capacitance-type transducer for measuring positions

Claim 2

(2) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (1), the second receiving electrodes and second transmitting electrodes are positioned so that the amount of deflection of the second scale is set at zero at the center of the second scale, and the deflection increases in the opposite direction, towards the plus or minus side, as both ends of the scale are approached.

Claim 3

(3) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (1) and (2), the adjacent groups of the first transmitting electrodes form blocks one after another, and A.C. signals with different phases are supplied to the first transmitting electrodes in each group, so that, if the pitch of this block is taken as the transmitting wavelength pitch, the aforesaid deflection will not exceed the aforesaid transmitting wavelength pitch within the measurable scale range.

Claim 4

(4) A capacitance type transducer for measuring positions characterized by the fact that, in the device described in Claim (3), the first receiving electrodes consist of a group of two types of electrodes for outputting signals of two different phases, and if the receiving wavelength pitch is Wr1, the aforesaid transmitting wavelength pitch is Wt1, the second receiving electrode pitch is Pr2, and the second transmitting electrode pitch is Pt2, the pitch of the group of first receiving electrodes is set at: Wr1 = Wt1 × Pt2/Pr2

Claim 5

(5) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (4), the first receiving electrodes consist of two electrodes with mutually reversed shapes.

Claim 6

(6) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (5), the aforesaid mutually reversed shapes of the aforesaid second receiving electrodes consist of sinusoidal shapes.

Claim 7

(7) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (5), the aforesaid mutually reversed shapes of the aforesaid second receiving electrodes consist of triangular wave shapes.

Claim 8

(8) A capacitance type transducer for measuring positions characterized by the fact that it has a first scale and a second scale which are positioned close to each other in a manner so that they can be displaced relatively to each other, the aforesaid first scale is provided with first transmitting electrodes to which A.C. signals are supplied and first receiving electrodes which are positioned in an insulated state with respect to the aforesaid first transmitting electrodes and to which a measuring circuit is connected, the aforesaid second scale is provided with second receiving electrodes which consist of groups of electrodes positioned along the relative displacement direction at positions where they can face towards the aforesaid first transmitting electrodes and which are coupled capacitively with the first transmitting electrodes, and second transmitting electrodes which consist of groups of electrodes positioned along the relative displacement direction at positions where they can face towards the first receiving electrodes and which are coupled capacitively with the first receiving electrodes, the second receiving electrodes and the second transmitting electrodes are connected electrically with each other by coupling electrodes, the connected second receiving electrodes and second transmitting electrodes are each given different deflections along the relative displacement direction, coarse absolute measurements can be carried out along the entire measuring range by means of the aforesaid deflections which are specified for each relative displacement position, the aforesaid second receiving electrodes consist of a number of electrodes having an equally spaced pitch equal to the transmitting wavelength pitch of the aforesaid group of first transmitting electrodes divided by a specific integer, and the aforesaid coarse dimensions can be measured finely with a scale precision equal to the aforesaid second receiving electrode pitch divided by the number of transmitting electrodes within the aforesaid group of first transmitting electrodes.

Claim 9

(9) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (8), the second receiving electrodes and the second transmitting electrodes are positioned so that the amount of deflection of the second scale is set at zero at the center of the second scale, and the deflection increases in the opposite direction, towards the plus or minus side, as both ends of the scale are approached.

Claim 10

(10) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (8) and (9), the adjacent groups of the first transmitting electrodes form blocks one after another, and A.C. signals with different phases are supplied to the first transmitting electrodes in each group, so that, if the pitch of this block is taken as the transmitting wavelength pitch, the aforesaid deflection will not exceed the aforesaid transmitting wavelength pitch within the measurable scale range.

Claim 11

(11) A capacitance type transducer for measuring positions characterized by the fact that, in the device described in Claim (10), the first receiving electrodes consist of a group of two types of electrodes for outputting signals of two different phases, and if the receiving wavelength pitch is Wr1, the aforesaid transmitting wavelength pitch is Wt1, the second receiving electrode pitch is Pr2, and the second transmitting electrode pitch is Pt2, the pitch of the group of first receiving electrodes is set at: Wr1 = Wt1 × Pt2/Pr2

Claim 12

(12) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (11), the first receiving electrodes consist of two electrodes with mutually reversed shapes.

Claim 13

(13) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (12), the aforesaid mutually reversed shapes of the aforesaid first receiving electrodes consist of sinusoidal shapes.

Claim 14

(14) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (12), the aforesaid mutually reversed shapes of the aforesaid first receiving electrodes consist of triangular wave shapes.

Claim 15

(15) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (8), the second receiving electrodes consist of a number of electrodes having an equally spaced pitch equal to the transmitting wavelength pitch of the aforesaid group of first transmitting electrodes divided by an integer less than the number of transmitting electrodes within the group of first transmitting electrodes.

Claim 16

(16) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (8) and (14), the first transmitting electrodes have an unequally spaced pitch.

Claim 17

(17) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (8) and (15), on the second scale are provided two sets of second receiving electrodes and second transmitting electrodes, on the first scale are provided two first receiving electrodes which face towards the aforesaid two second transmitting electrodes and are coupled capacitively with them, and measuring operations can be performed by combining the two receiving signals.

Claim 18

(18) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (17), the aforesaid two second receiving electrodes are both coupled capacitively with a single first transmitting electrode on the first scale side.

Claim 19

(19) A capacitance type transducer for measuring positions characterized by the fact that it has a first scale and a second scale which are positioned close to each other in a manner so that they can be displaced relatively to each other, the aforesaid first scale is provided with first transmitting electrodes to which A.C. signals are supplied as well as first coarse/fine receiving electrodes and first medium/fine receiving electrodes which are each positioned in an insulated state with respect to the aforesaid first transmitting electrodes and to which a measuring circuit is connected, the aforesaid second scale is provided with second receiving electrodes which consist of groups of electrodes positioned along the relative displacement direction at positions where they can face towards the aforesaid first transmitting electrodes and which are coupled capacitively with the first transmitting electrodes, and second coarse/fine transmitting electrodes and second medium/fine receiving electrodes which consist of groups of electrodes positioned along the relative displacement direction at positions where they can face towards the first coarse/fine receiving electrodes and the first medium/fine receiving electrodes and which are each coupled capacitively with the first coarse/fine receiving electrodes and the first medium/fine receiving electrodes, the second receiving electrodes and the second coarse/fine transmitting electrodes are connected electrically with each other by coupling electrodes, the connected second receiving electrodes and second coarse/fine transmitting electrodes are each given different coarse deflections within the entire measuring range along the relative displacement direction, coarse absolute measurements can be carried out along the entire measuring range by means of the aforesaid coarse deflections which are specified for each relative displacement position, the aforesaid second receiving electrodes and second medium/fine transmitting electrodes are connected electrically with each other by coupling electrodes, and the connected second receiving electrodes and second medium/fine transmitting electrodes are each given different medium deflections along the relative displacement direction within the medium measuring range equal to the aforesaid entire measuring range divided into specified fractions, medium absolute measurements can be made within the medium measuring range by means of the aforesaid medium deflections specified for each relative displacement position, the aforesaid second receiving electrodes consist of a number of electrodes having an equally spaced pitch equal to the transmitting wavelength pitch of the aforesaid group of first transmitting electrodes divided by a specific integer, and the aforesaid medium dimensions can be measured finely with a scale precision equal to the aforesaid second receiving electrode pitch divided by the number of transmitting electrodes within the aforesaid group of first transmitting electrodes.

Claim 20

(20) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (19), the second receiving electrodes and the second coarse/fine transmitting electrodes are positioned so that the amount of coarse deflection of the second scale is set at zero at the center of the second scale, and the deflection increases in the opposite direction, towards the plus or minus side, as both ends of the scale are approached.

Claim 21

(21) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (19) and (20), the adjacent groups of the first transmitting electrodes form blocks one after another, and A.C. signals with different phases are supplied to the first transmitting electrodes in each group, so that, if the pitch of this block is taken as the transmitting wavelength pitch, the aforesaid two deflection will not exceed the aforesaid transmitting wavelength pitch within the measurable scale range.

Claim 22

(22) A capacitance type transducer for measuring positions characterized by the fact that, in the device described in Claim (21), the first coarse/fine receiving electrodes and first medium/fine receiving electrodes consist of groups of two types of electrodes for outputting signals each of two different phases, if the coarse/fine receiving wavelength pitch is Wr1, the aforesaid transmitting wavelength pitch is Wt1, the second receiving electrode pitch is Pr2, and the second coarse/fine transmitting electrode pitch is Pt2, the pitch of the group of first coarse/fine receiving electrodes is set at: Wr1 = Wt1 × Pt2/Pr2, if the medium/fine receiving wavelength pitch is Wmr1 and the aforesaid first medium/fine transmitting electrode pitch is Pmt2, the pitch of the group of first medium/fine receiving electrodes is set at: Wmr1 = Wt1 × Pmt2/Pr2

Claim 23

(23) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (22), the first receiving electrodes each consist of two electrodes with mutually reversed shapes.

Claim 24

(24) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (23), the aforesaid mutually reversed shapes of the aforesaid first receiving electrodes consist of sinusoidal shapes.

Claim 25

(25) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (23), the aforesaid mutually reversed shapes of the aforesaid first receiving electrodes consist of triangular wave shapes.

Claim 26

(26) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (19), the second receiving electrodes consist of a number of electrodes having an equally spaced pitch equal to the transmitting wavelength pitch of the aforesaid group of first transmitting electrodes divided by an integer less than the number of transmitting electrodes within the group of first transmitting electrodes.

Claim 27

(27) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (19) and (26), the first transmitting electrodes have an unequally spaced pitch.

Claim 28

(28) A capacitance type transducer for measuring positions characterized by the fact that, in either one of the transducers described in Claims (19) and (26), on the second scale are positioned, in a state electrically insulated from each other, the second coarse/fine receiving electrodes and second medium/fine receiving electrodes in positions where they can be coupled capacitively with the first transmitting electrodes, and the second coarse/fine transmitting electrodes or second medium/fine transmitting electrodes are electrically connected to the second receiving electrodes through coupling electrodes with the prescribed coarse deflection or medium deflection.

Claim 29

(29) A capacitance type transducer for measuring positions characterized by the fact that, in the transducer described in Claim (28), the aforesaid second coarse/fine receiving electrodes and second medium/fine receiving electrodes consist of a half-wave sinusoidal shape positioned in mutually reversed shapes with electrical phase differences of 180 degrees.