Inductive encoder

Abstract

[Problem] To provide an inductive encoder that can be miniaturized.　[Solution] An inductive encoder 10 is composed of a fixed-side substrate 5 and a rotation-side substrate 2. The fixed-side substrate 5 has: an exciting coil pattern 8 common to a shaft angle multiplier 1X and a shaft angle multiplier nX, where n is an integer equal to or greater than 2; a total of four output coil patterns 6, specifically a COS output coil pattern 7C1 and a SIN output coil pattern 7S1 of the shaft angle multiplier 1X, and a COS output coil pattern 7Cn and a SIN output coil pattern 7Sn of the shaft angle multiplier nX; and a signal processing circuit 9 for processing an output signal. The rotation-side substrate 2 has a detection pattern 3 for rotation angle detection, the detection pattern 3 being formed by using one or a plurality of basic patterns 4 that are fan-shaped patterns having electrical conductivity.

Description

Inductive Encoder

[0001] The present invention relates to an inductive encoder, and more particularly to an inductive encoder that can be miniaturized.

[0002] Patent applications have also been filed for inductive encoders. For example, Patent Document 1 listed below discloses an electromagnetic induction type rotation sensor and a shaft encoder with small outer dimensions that achieve high-quality signals even with a minimal structure, in which an excitation land pattern and a receiving land pattern are formed on a printed circuit board, the receiving land pattern has a first portion extending in a first plane and a second portion extending in a second plane, the electromagnetic induction type rotation sensor has graduation elements and a graduation track that rotate relative to the printed circuit board, the graduation track is made up of conductive graduation areas and non-conductive graduation areas arranged alternately, the receiving land pattern supplies an odd number of signal periods within one rotation of the graduation element, and the first portion of the receiving land pattern has a longer length than the second portion.

[0003] JP 2004-333478 A: "Electromagnetic induction type rotation sensor and shaft encoder equipped with this electromagnetic induction type rotation sensor"

[0004] However, the above-mentioned encoder also has a problem: when detecting rotation angles with a shaft angle multiplier of 1X and a shaft angle multiplier of nX, the fan-shaped conductive patterns on the rotating-side printed circuit board are separate for the shaft angle multiplier of 1X and the shaft angle multiplier of nX, making it difficult to reduce the outer diameter of the rotating-side printed circuit board (see Figures 1 and 2 of the above-mentioned document).

[0005] SUMMARY OF THE INVENTION In view of the problems of the prior art, the problem to be solved by the present invention is to provide an inductive encoder that can be made smaller.

[0006] As a result of studying the above problems, the inventors of the present application came up with the following configurations: - An encoder comprising a fixed-side printed circuit board and a rotating-side printed circuit board. - An encoder capable of detecting rotation angles for shaft angle multipliers 1X and nX. - The fixed-side printed circuit board has an excitation coil pattern common to shaft angle multipliers 1X and nX, a cosine output coil pattern and a sine output coil pattern for shaft angle multiplier 1X, a cosine output coil pattern and a sine output coil pattern for shaft angle multiplier nX, and a signal processing circuit for processing output signals. - The cosine and sine output coil patterns for shaft angle multiplier 1X and the cosine and sine output coil patterns for shaft angle multiplier nX are arranged on separate layers of the printed circuit board.

[0007] - The number of layers of the fixed-side printed circuit board is at least four. - The rotating-side printed circuit board has a sectorial conductive pattern, and since the sectorial conductive pattern is common to both the axial angle multiplier 1X and the axial angle multiplier nX, the central angle of the sector and the arrangement interval are 360 / (2n), and the number of sectorial conductive patterns is n / 2. - The number of layers of the rotating-side printed circuit board is at least one. Based on these configurations, further investigation led to the completion of the present invention. That is, the invention claimed in this application, or at least the invention disclosed therein, as a means for solving the above problems is as follows.

[0008] [1] An inductive encoder comprising a fixed-side substrate and a rotating-side substrate, wherein the fixed-side substrate has four output coil patterns: an excitation coil pattern common to shaft angle multiplier 1X and shaft angle multiplier nX, a COS output coil pattern and a SIN output coil pattern for shaft angle multiplier 1X, and a COS output coil pattern and a SIN output coil pattern for shaft angle multiplier nX, where n is an integer of 2 or greater; and a signal processing circuit for processing output signals, wherein the rotating-side substrate has a detection pattern for detecting a rotation angle, wherein the detection pattern is configured using one or more basic patterns which are conductive sector-shaped patterns, and is a pattern capable of detecting the rotation angle for both shaft angle multiplier 1X and shaft angle multiplier nX. [2] The inductive encoder according to [1], wherein the number of basic patterns used to configure the detection pattern is 1 or greater and n-1 or less. [3] The inductive encoder according to [1], characterized in that the central angle and arrangement interval of the sectors of the detection patterns are approximately 360 / (2n) [°]. [4] The inductive encoder according to any one of [1], [2], and [3], characterized in that the fixed-side substrate has at least two layers on which the output coil patterns are provided.

[0009] [5] The inductive encoder according to any one of [1], [2], and [3], characterized in that the output coil pattern for shaft angle multiplier 1X and the output coil pattern for shaft angle multiplier nX are arranged on different layers on the fixed-side substrate. [6] The inductive encoder according to any one of [1], [2], and [3], characterized in that one output coil pattern is arranged on one or more layers on the fixed-side substrate. [7] The inductive encoder according to any one of [1], [2], and [3], characterized in that one or more output coil patterns are arranged on one layer on the fixed-side substrate.

[0010] Because the inductive encoder of the present invention is configured as described above, the outer diameter of the rotating substrate can be sized to match the outer diameter of the fixed substrate, or can be the same size as the outer diameter of the fixed substrate. In other words, the planar shape of the encoder can be reduced in the radial direction, thereby making the encoder more compact.

[0011] FIG. 1 is a conceptual diagram showing the basic configuration of an inductive encoder according to the present invention. FIG. 2 is an explanatory diagram conceptually showing a first example of a layer configuration of a fixed-side substrate of an inductive encoder according to the present invention. FIG. 3 is an explanatory diagram conceptually showing a second example of a layer configuration of a fixed-side substrate of an inductive encoder according to the present invention. FIG. 4 is an explanatory diagram conceptually showing a fourth example of a layer configuration of a fixed-side substrate of an inductive encoder according to the present invention. The following drawings are explanatory diagrams of embodiments. FIG. 1 is an explanatory diagram of an output coil pattern (1X) of a fixed-side substrate. FIG. 2 is an explanatory diagram of a SIN output coil pattern (1X) of a fixed-side substrate. FIG. 3 is an explanatory diagram of a COS output coil pattern (1X) of a fixed-side substrate. FIG. 4 is an explanatory diagram of an excitation coil pattern of a fixed-side substrate. FIG. 5 is an explanatory diagram of a rotating-side substrate according to the prior art. FIG. 6 is an explanatory diagram of an arrangement example (1X) when used as an inductive encoder. FIG. 7 is an explanatory diagram of an arrangement example (1X, prior art) when used as an inductive encoder. FIG. 8 is an explanatory diagram of an output coil pattern (4X) of a fixed-side substrate. FIG. 1 is an explanatory diagram of a SIN output coil pattern (4X) on a fixed side substrate. FIG. 2 is an explanatory diagram of a COS output coil pattern (4X) on a fixed side substrate. FIG. 3 is an explanatory diagram of an excitation coil pattern on a fixed side substrate. FIG. 4 is an explanatory diagram of a rotating side substrate of the prior art. FIG. 5 is an explanatory diagram of an example arrangement (4X) when used as an inductive encoder. FIG. 6 is an explanatory diagram of an example arrangement (4X, prior art) when used as an inductive encoder. FIG. 7 is an explanatory diagram showing the planar configuration of an inductive encoder. FIG. 8 is an explanatory diagram showing the side cross-sectional configuration of an inductive encoder. FIG. 9 is an explanatory diagram (part 1) showing a schematic example of a detection pattern on a rotating side substrate of an inductive encoder of the present invention. FIG. 10 is an explanatory diagram (part 2) showing a schematic example of a detection pattern on a rotating side substrate of an inductive encoder of the present invention.

[0012] The present invention will be described in detail below with reference to the drawings. FIG. 1 is a conceptual diagram showing the basic configuration of an inductive encoder 10 according to the present invention. As shown, this inductive encoder 10 comprises a fixed-side substrate 5 and a rotating-side substrate 2. The fixed-side substrate 5 has four output coil patterns 6: an excitation coil pattern 8 common to both 1X and nX shaft multipliers, a COS output coil pattern 7C1 and a SIN output coil pattern 7S1 for the 1X shaft multiplier, and a COS output coil pattern 7Cn and a SIN output coil pattern 7Sn for the nX shaft multiplier, where n is an integer greater than or equal to 2; and a signal processing circuit 9 for processing output signals. The rotating-side substrate 2 also has a detection pattern 3 for detecting the rotation angle. The detection pattern 3 is formed using one or more basic patterns 4, which are conductive fan-shaped patterns. This is the basic configuration of the inductive encoder 10. Printed circuit boards can be suitably used for the rotating-side substrate 2 and the fixed-side substrate 5.

[0013] In the inductive encoder 10 having such a configuration, the excitation coil pattern 8 on the fixed side substrate 5 excites the output coil patterns 6 of both the 1X axial angle multiplier and the nX axial angle multiplier, i.e., the COS output coil pattern 7C1 and SIN output coil pattern 7S1 of the 1X axial angle multiplier, and the COS output coil pattern 7Cn and SIN output coil pattern 7Sn of the nX axial angle multiplier.

[0014] Furthermore, the rotation angle is detected by the detection pattern 3 formed on the rotating substrate 2 using one or more basic patterns 4. That is, as the detection pattern 3 rotates, an output reflecting this is produced by each output coil pattern 6, and the output signal is processed by the signal processing circuit 9 and detected as the rotation angle. The inductive encoder 10 of the present invention can detect both a rotation angle with a shaft multiplier of 1X and a rotation angle with a shaft multiplier of nX. The embodiment described below is an example of a shaft multiplier of 4X, but shaft multipliers of 2X, 3X, or even shaft multipliers greater than 4X, such as 8X and 16X, are also possible.

[0015] In the inductive encoder 10 of the present invention that detects rotation angles with shaft angle multiplication factors 1X and nX, the number of basic patterns 4 used in the detection pattern 3 can be 1 to n-1 (n is an integer of 2 or greater). This will also be described in the explanation using Figure 23. The number of basic patterns 4 is n / 2 or greater.

[0016] Furthermore, in this inductive encoder 10, the central angle and spacing of the sector-shaped basic pattern 4 associated with the detection pattern 3 are approximately 360 / (2n)°. This is not strictly limited to 360 / (2n)°, and it is within the scope of the present invention to set the central angle and spacing to approximately ±5°. The central angle of the basic pattern 4 is 90° or less.

[0017] The number of layers in the rotation-side substrate 2 of this inductive encoder 10 is one or more. That is, at least one layer is required, but two or more layers are also acceptable. For example, if one layer of material such as copper foil that forms the detection pattern 3 is not thick enough, the detection pattern 3 may be configured with multiple layers, such as two or four layers.

[0018] 2 is an explanatory diagram conceptually showing a first example of the layer configuration of the fixed-side substrate of the inductive encoder of the present invention. As shown in the figure, the fixed-side substrate 25 of this inductive encoder 210 can be configured so that the layer on which the output coil pattern 26 is provided is formed of at least two layers.

[0019] 3 is an explanatory diagram conceptually showing a second example of the layer configuration of the fixed-side substrate of the inductive encoder of the present invention. As shown in the figure, this inductive encoder 310 can be configured such that the output coil patterns for the axial multiplier angle 1X, i.e., COS output coil pattern 37C1 and SIN output coil pattern 37S1, and the output coil patterns for the axial multiplier angle nX, i.e., COS output coil pattern 37Cn and SIN output coil pattern 37Sn, are arranged on different layers on the fixed-side substrate 35.

[0020] 4 is an explanatory diagram conceptually illustrating a third example of the layer configuration of the fixed substrate of the inductive encoder of the present invention. As shown in (i) of the figure, this inductive encoder 410a can be configured such that one output coil pattern 47a, i.e., at least one COS output pattern or one SIN output pattern, is arranged on one layer on its fixed substrate 45a. Also, as shown by 47b, 47c, 47d, and 47e in the inductive encoder 410b of (ii) of the figure, one output coil pattern, i.e., at least one COS output pattern or one SIN output pattern, can be arranged across two or more layers. Note that in this figure, output coil patterns other than those indicated as "47a," "47b," etc., as "one output coil pattern" are omitted.

[0021] FIG. 4-2 is an explanatory diagram conceptually illustrating a fourth example of the layer configuration of the fixed-side substrate of the inductive encoder of the present invention. As shown in (i) of the figure, this inductive encoder 410f can be configured such that one output coil pattern (COS output pattern) 47a and one output coil pattern (SIN output pattern) 47a' are each arranged on a single layer on its fixed-side substrate 45f. Also, as shown in (ii) of the figure, inductive encoder 410g, one output coil pattern (COS output pattern) can be arranged on two or more layers, as indicated by 47g, 47h, 47j, and 47k, or one output coil pattern (SIN output pattern) can be arranged on two or more layers, as indicated by 47g', 47h', 47j', and 47k'. Although not shown, this inductive encoder can also be configured such that one or more output coil patterns are arranged on a single layer on its fixed-side substrate.

[0022] Below, examples of the present invention will be described, but the present invention is not limited to these. Note that the present invention is an inductive encoder that can detect both rotation angles with a shaft multiplier of 1X and rotation angles with a shaft multiplier of nX, where n is an integer greater than or equal to 2. Therefore, the shaft multiplier nX can be set to 8X, 16X, or any other appropriate rotation angle as a shaft multiplier that can be detected along with the shaft multiplier of 1X, but in the examples, an example will be described where n=4, i.e., a shaft multiplier of 4X.

[0023] Example — Inductive Encoder for Detecting Rotation Angle with 1X and 4X Shaft Angle Multipliers and Reduced Outer Diameter This inductive encoder 510 is an inductive encoder for detecting angles, which combines a fixed-side substrate 55 combining a 1X shaft angle multiplier output coil pattern 501 shown in Fig. 5 and a 4X shaft angle multiplier output coil pattern 504 shown in Fig. 13 with a rotating-side substrate 52 shown in Fig. 9. Printed circuit boards are used for the rotating-side substrate 52 and the fixed-side substrate 55. Note that the dotted lines in each diagram showing the coil patterns indicate portions that are formed on a different layer of the substrate to avoid interference with other coil patterns.

[0024] The 1X shaft angle multiplier output coil pattern 501 shown in Fig. 5 is formed by combining multiple coil patterns. That is, the SIN output coil pattern 57S1 shown in Fig. 6, the COS output coil pattern 57C1 shown in Fig. 7, and the excitation coil pattern 581 shown in Fig. 8. These are combined to form the 1X shaft angle multiplier output coil pattern 501. Each of the coil patterns 57C1, 57S1, and 581 extending from the fixed-side substrate 55 is connected to a corresponding location in the signal processing circuit 59. Note that the excitation coil pattern 581 and the excitation coil pattern 584 (Fig. 16) of the 4X shaft angle multiplier output coil pattern 504 (Fig. 13), which will be described later, can be formed into the same pattern.

[0025] Fig. 9 shows the configuration of the rotation-side substrate 52 of the inductive encoder 510 of the present invention. Fig. 10 shows the configuration of the rotation-side substrate 921 of the prior art. As shown in the figure, the central angle of the sector of the 1X shaft angle multiplier detection pattern 931 of the prior art is 180°, i.e., it is a semicircular arc. On the other hand, the detection pattern 53 of the inductive encoder 510 of the present invention is formed by two sector-shaped basic patterns 54 with a central angle of approximately 45°, arranged at an interval of approximately 45°.

[0026] In the present invention, not only the axial multiplier of 1X but also the axial multiplier of 4X (described later) can be detected using a single detection pattern 53. On the other hand, in the prior art, a separate pattern for detecting the axial multiplier of 4X is required (see FIG. 17 below).

[0027] Fig. 11 is a diagram in which the 1X shaft angle multiplier output coil pattern 501 of the inductive encoder 510 is superimposed on the rotating-side substrate 52. The rotating-side substrate 52 rotates over the 1X shaft angle multiplier output coil pattern 501 provided on the fixed-side substrate 55. Fig. 12 is a diagram in which the 1X shaft angle multiplier output coil pattern 501 shown in Fig. 5 is superimposed on the rotating-side substrate 921 of the prior art shown in Fig. 10.

[0028] The 4X shaft angle multiplier output coil pattern 504 shown in Fig. 13 is formed by combining multiple coil patterns. That is, the SIN output coil pattern 57S4 shown in Fig. 14, the COS output coil pattern 57C4 shown in Fig. 15, and the excitation coil pattern 584 shown in Fig. 16. These are combined to form the 4X shaft angle multiplier output coil pattern 504. Each of the coil patterns 57C4, 57S4, and 584 extending from the substrate 55 is connected to a corresponding location in the signal processing circuit 59. Note that the excitation coil pattern 584 and the excitation coil pattern 581 (Fig. 8) of the 1X shaft angle multiplier output coil pattern 501 (Fig. 5) described above can be formed into the same pattern.

[0029] The configuration of the rotation-side substrate 52 of the present inductive encoder 510 is as shown in Figure 9 above. Figure 17 shows the configuration of a rotation-side substrate 924 of the prior art. As shown in the figure, the central angle of the sector of the 4X shaft angle multiplier detection pattern 934 in the prior art is 45°, and four of these are arranged at equal intervals of 45°. This results in a point-symmetrical pattern as a whole. On the other hand, the detection pattern 53 of the inductive encoder 510 of the present invention is formed by two sector-shaped basic patterns 54 with a central angle of approximately 45° arranged at intervals of approximately 45°, as described above, and is not formed in a point-symmetrical pattern as a whole.

[0030] In the present invention, not only the axial multiplier angle of 1X but also the axial multiplier angle of 4X can be detected using a single detection pattern 53. On the other hand, in the prior art, a separate pattern for detecting the axial multiplier angle of 1X is required (see FIG. 10 above).

[0031] Fig. 18 is a diagram in which the 4X shaft angle multiplier output coil pattern 504 of the inductive encoder 510 is superimposed on the rotating-side substrate 52. The rotating-side substrate 52 rotates over the 4X shaft angle multiplier output coil pattern 504 provided on the fixed-side substrate 55. Fig. 19 is a diagram in which the 4X shaft angle multiplier output coil pattern 504 shown in Fig. 13 is superimposed on the rotating-side substrate 924 of the prior art shown in Fig. 17.

[0032] FIG. 20 is an explanatory diagram showing the planar configuration of an inductive encoder 510. However, the rotating-side substrate is not shown. FIG. 21 is an explanatory diagram showing the side cross-sectional configuration of the inductive encoder 510. As shown in the figure, a single rotating-side substrate 52 is used as the rotating-side substrate. The rotating-side substrate 52 is provided with a 1X shaft multiplier output coil pattern 501 and a 4X shaft multiplier output coil pattern 504, both of which are provided on a fixed-side substrate 55, and with detection patterns 53 corresponding to both of them. Unlike conventional technologies such as the technology disclosed in the above-mentioned document 1, in which the inner diameter side of the substrate is configured as a 1X pattern and the outer diameter side is configured as a 16X pattern, the rotating-side substrate 52 and the fixed-side substrate 55 are arranged three-dimensionally rather than being arranged in a planar direction, so that the outer diameter of the rotating-side substrate 52 can be reduced to match the outer diameter of the fixed-side substrate 55.

[0033] In other words, in the technology disclosed in the above document, when printing the fan-shaped conductive pattern and the coil pattern, the outer diameter of the substrate must be large because they are arranged on the same substrate. However, in the present inductive encoder 510, the outer diameter of the rotating-side substrate 52 can be sized to match the outer diameter of the fixed-side substrate 55, and can even be made the same size as the outer diameter of the fixed-side substrate 55. This allows the planar shape of the encoder to be reduced in the radial direction, making the encoder more compact.

[0034] The fixed-side substrate 55 of the inductive encoder of the present invention can be configured to have four or more layers, and each output coil pattern can be provided on a different layer. As shown in Figure 21, in the inductive encoder 510 of this embodiment, a 1X shaft angle multiplier output coil pattern 501 is formed on the first and second layers of the four-layer fixed-side substrate 55, and a 4X shaft angle multiplier output coil pattern 504 is formed on the third and fourth layers.

[0035] The excitation coil pattern of the inductive encoder 510 can be formed on only one layer of the four-layer fixed substrate 55, or on any number of layers from the first to fourth layers, or on all layers (not shown). In this way, when the fixed substrate has multiple layers, there is no limit to the number of layers on which the excitation coil pattern is provided. A configuration in which excitation coil patterns are provided on multiple layers is significant in meeting the demand for optimization depending on the number of elements corresponding to the number of coil turns in each output coil pattern 57C1, for example.

[0036] 21 is configured with four layers, such as a coil pattern 57C1 made of copper foil, provided at each boundary between three insulators 550. However, it goes without saying that the present invention is not limited to this. In other words, the number of layers, the number of insulators used to form the layers, and the number of layers forming the coil patterns for each axial angle multiplier (1X, nX) can be designed as appropriate.

[0037] For example, a configuration in which only one insulator is used and the coil pattern is in two layers is also possible, or a configuration in which the output coil pattern for nX, including the axial angle multiplier of 4X, is divided into four layers is also possible. This degree of freedom in design makes it possible to respond to requests for optimization depending on the number of elements corresponding to the number of coil turns in each output coil pattern 57C1, etc. However, a configuration with more than eight layers is not necessary.

[0038] 22 and 23 are explanatory diagrams schematically showing examples of detection patterns on a rotation-side substrate in an inductive encoder according to the present invention. In the figures, a rotation-side substrate 622 is an example of a configuration in which shaft angle multiplication factors of 1X and 2X can be detected using a single substrate. On this rotation-side substrate 622, a detection pattern 632 is formed using a single basic pattern 642. The central angle of the sector is approximately 90°.

[0039] The rotation-side substrate 623 is an example of a configuration that can detect shaft angle multiplication factors of 1X and 3X using a single substrate. The rotation-side substrate 623 has a detection pattern 633 formed by two basic patterns 643. The central angle of the sector and the distance between adjacent basic patterns 643-643 are approximately 60°.

[0040] The rotation-side substrate 624a is an example of a configuration in which the substrate alone can detect shaft angle multiplication factors of 1X and 4X. The rotation-side substrate 624a has a detection pattern 634a formed by two basic patterns 644. The central angle of the sector and the spacing between adjacent basic patterns 644-644 are approximately 45°.

[0041] The rotation-side substrate 624b is an example of a configuration in which the substrate alone can detect shaft angle multiplication factors of 1X and 4X. The rotation-side substrate 624b has a detection pattern 634b formed by three basic patterns 644. The central angle of the sector and the spacing between adjacent basic patterns 644-644 are approximately 45°.

[0042] The rotation-side substrate 625a is an example of a configuration that can detect shaft angle multiplication factors of 1X and 5X using a single substrate. The rotation-side substrate 625a has a detection pattern 635a formed by two basic patterns 645. The central angle of the sector and the distance between adjacent basic patterns 645-645 are approximately 36°.

[0043] The rotation-side substrate 625b is an example of a configuration in which this substrate alone can detect shaft angle multiplication factors of 1X and 5X. This rotation-side substrate 625b has a detection pattern 635b formed by three basic patterns 645. The central angle of the sector and the spacing between adjacent basic patterns 645-645 are approximately 36°.

[0044] The rotation-side substrate 625c is an example of a configuration in which the substrate alone can detect shaft angle multiplication factors of 1X and 5X. The rotation-side substrate 625c has a detection pattern 635c formed by four basic patterns 645. The central angle of the sector and the spacing between adjacent basic patterns 645-645 are approximately 36°.

[0045] The rotation-side substrate 626a is an example of a configuration that can detect shaft angle multiplication factors of 1X and 6X using a single substrate. The rotation-side substrate 626a has a detection pattern 636a formed by two basic patterns 646. The central angle of the sector and the spacing between adjacent basic patterns 646-646 are approximately 30°.

[0046] The rotation-side substrate 626b is an example of a configuration that can detect shaft angle multiplication factors of 1X and 6X using a single substrate. This rotation-side substrate 626b has a detection pattern 636b formed from three basic patterns 646. The central angle of the sector and the spacing between adjacent basic patterns 646-646 are approximately 30°.

[0047] The rotation-side substrate 626c is an example of a configuration in which the substrate alone can detect shaft angle multiplication factors of 1X and 6X. The rotation-side substrate 626c has a detection pattern 636c formed of four basic patterns 646. The central angle of the sector and the spacing between adjacent basic patterns 646-646 are approximately 30°.

[0048] The rotation-side substrate 626d is an example of a configuration that can detect shaft angle multiplication factors of 1X and 6X using a single substrate. This rotation-side substrate 626d has a detection pattern 6326d formed from five basic patterns 646. The central angle of the sector and the spacing between adjacent basic patterns 646-646 are approximately 30°.

[0049] The inductive encoder of the present invention allows the encoder to be miniaturized, and is therefore an invention with high industrial applicability in the fields of encoder manufacturing, use, and all related fields.

[0050] 2, 22, 32, 42a, 42b, 42f, 42g, 52, 622, 623, 624a, 624b, 625a, 625b, 625c, 626a, 626b, 626c, 626d... Rotating side substrate 3, 53, 632, 633, 634a, 634b, 635a, 635b, 635c, 636a, 636b, 636c, 636d... Detection patterns 4, 54, 642, 643, 644, 645, 646... Basic patterns 5, 25, 35, 45a, 45b, 45f, 45g, 55... Fixed side substrate 6, 26, 27, 47a, 47b, 47c, 47d, 47e, 47f, 47f', 47g, 47g', 47h, 47h', 47j, 47j', 47k, 47k'...output coil patterns 7C1, 37C1, 57C1...COS output coil pattern with shaft multiplier angle 1X 7S1, 37S1, 57S1...SIN output coil pattern with shaft multiplier angle 1X 7Cn, 37Cn...COS output coil pattern with shaft multiplier angle nX 7Sn, 37Sn...SIN output coil pattern with shaft multiplier angle nX 8, 581, 584...excitation coil patterns 9, 59...signal processing circuit 10, 210, 310, 410a, 410b, 410f, 410g, 510...inductive encoder 57C4...COS output coil pattern for 4X shaft multiplier 57S4...SIN output coil pattern for 4X shaft multiplier 501...1X shaft multiplier output coil pattern 504...4X shaft multiplier output coil pattern 550...insulator 921, 924...rotation side substrate of prior art 931...1X shaft multiplier detection pattern in prior art 934...4X shaft multiplier detection pattern in prior art

Claims

1. An inductive encoder comprising a fixed-side substrate and a rotating-side substrate, wherein the fixed-side substrate has four output coil patterns: an excitation coil pattern common to shaft multiplier angle 1X and shaft multiplier angle nX, where n is an integer of 2 or greater; a COS output coil pattern and a SIN output coil pattern for shaft multiplier angle 1X; and a COS output coil pattern and a SIN output coil pattern for shaft multiplier angle nX; and a signal processing circuit for processing output signals; and the rotating-side substrate has a detection pattern for detecting the rotation angle, which is configured using one or more basic patterns that are conductive fan-shaped patterns, and is a pattern that can detect the rotation angle of both shaft multiplier angle 1X and shaft multiplier angle nX.

2. The inductive encoder according to claim 1, wherein the number of basic patterns used that make up the detection pattern is 1 or more and n-1 or less.

3. The inductive encoder according to claim 1, wherein the central angle and spacing of the sectors of the detection patterns are approximately 360 / (2n) [°].

4. An inductive encoder according to any one of claims 1, 2 and 3, wherein the fixed substrate has at least two layers on which the output coil pattern is provided.

5. An inductive encoder according to any one of claims 1, 2 and 3, characterized in that on the fixed side substrate, the output coil pattern with axial multiplier 1X and the output coil pattern with axial multiplier nX are arranged on different layers.

6. The inductive encoder according to any one of claims 1, 2 and 3, wherein on the fixed substrate, one of the output coil patterns is arranged on one or more layers.

7. The inductive encoder according to any one of claims 1, 2 and 3, wherein one or more of the output coil patterns are arranged on one layer of the fixed substrate.

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