JP5014968B2 - Position sensor - Google Patents

Description

  The present invention relates to a position sensor that detects a designated two-dimensional position.

  As a conventional technique, a magnet plate that is displaced in conjunction with the displacement of a shift lever, a first yoke and a second yoke that have a pair of magnetic plates that are plate-like magnetic bodies arranged facing each other, and a magnet There is known a position sensor including a magnetic detection element for measuring a change in magnetic flux density generated from a magnet of a plate (for example, Patent Document 1).

  This magnet plate is formed of a substantially fan-like plate-like member in which non-magnetic portions that are non-magnetic bodies and magnet bodies that are magnetic bodies are alternately arranged in the circumferential direction. The first and second yokes include first and second bridge portions that hold the pair of magnetic plates in a state where the first and second gaps, which are predetermined gaps, are provided.

According to this position sensor, the magnet plate is displaced by the displacement of the shift lever, and the magnetic flux density detected by the magnetic detection element changes stepwise according to the number of magnet bodies accommodated in the first or second yoke. Therefore, it becomes possible to detect the shift position of the shift lever based on the detected magnetic flux density.
JP 2007-40722 A

  However, according to the conventional position sensor, the change width of the magnetic flux density detected by the magnetic detection element is small, and there is a possibility of malfunction due to the influence of the external magnetic field.

  Accordingly, an object of the present invention is to provide a position sensor that can stably detect a two-dimensional position by non-contact.

(1) In order to achieve the above object, the present invention provides an operation unit that indicates a two-dimensional position by performing a tilting operation, and is provided in the operation unit and is magnetized in a direction perpendicular to the direction in which the tilting operation is performed. The counter magnet and the first and second magnetoresistive elements whose magnetic sensing directions are orthogonal to each other, and the length direction of the first magnetoresistive element is relative to one direction of the two-dimensional position. A half bridge circuit that is inclined by 45 ° and the length direction of the second magnetoresistive element is inclined by −45 ° is arranged in the same direction as the first to fourth half bridges at each vertex of the cross, Based on the change in the direction of the magnetic field of the counter magnet based on the tilting operation, the first output voltage from the first and third half bridges facing each other, and the second and fourth half bridges facing each other. A magnetic sensor that outputs a second output voltage; and a detector that detects the two-dimensional position indicated by the tilting operation based on the first and second output voltages output from the magnetic sensor; A position sensor is provided.

  According to the configuration described above, a two-dimensional position can be stably detected by non-contact.

(2) In order to achieve the above object, the present invention provides an operation unit that indicates a two-dimensional position by performing a tilting operation, and is provided in the operation unit and is magnetized in a direction perpendicular to the direction in which the tilting operation is performed. The counter magnet and the surface facing the counter magnet are arranged so as to be the same pole as the corresponding counter magnet, and the first and The first magnetoresistive element is composed of a second magnetoresistive element, the length direction of the first magnetoresistive element is inclined by 45 ° with respect to one direction of the two-dimensional position, and the length direction of the second magnetoresistive element Are arranged in the same direction as the first to fourth half bridges at each vertex of the cross to change the direction of the bias magnetic field based on the tilting operation. And a magnetic sensor that outputs a first output voltage from the first and third half bridges facing each other and a second output voltage from the second and fourth half bridges facing each other, and the magnetic A position sensor comprising: a detection unit that detects the two-dimensional position instructed by the tilting operation based on a positive / negative combination of the first and second output voltages output from the sensor. provide.

  According to the configuration described above, a two-dimensional position can be detected more stably by non-contact.

  According to such a configuration, it is possible to provide a position sensor that can stably detect a two-dimensional position by non-contact.

  Hereinafter, embodiments of the position sensor of the present invention will be described in detail with reference to the drawings.

[First embodiment]
(Configuration of joystick 1)
FIG. 1 is a schematic view of a joystick according to the first embodiment of the present invention. FIG. 2 (a) is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. These are equivalent circuit diagrams of the MR sensor according to the first embodiment of the present invention. A case where the position sensor of the present invention is used in a joystick 1 mounted on a vehicle (not shown) will be described. 2A shows the magnetic vector 8 when the counter magnet 2 is not provided, and FIGS. 2A and 2B are the same in the xy coordinate system directions. In (b), the display of the coordinate system is omitted.

  The joystick 1 includes a knob 10 as an operation unit, a lever 11, a first support unit 12, a first pin 13, a second support unit 14, a second pin 15 and a base 16, and a counter magnet 2 described later. , An MR (Magneto Resistance) sensor 3 to be described later, a bias magnet 4 to be described later, and a determination unit 5 as a detection unit to be described later are schematically configured. The determination unit 5 may be integrated with the MR sensor 3 as an IC (Integrated Circuit), and an ECU (Electronic Control Unit) 6 described later may have the function of the determination unit 5.

  The joystick 1 has a pair of convex portions 16a that rises in the vertical direction from the upper surface of the base 16 and faces each other. The second pin 15 inserted into the opening provided in the convex portion 16a is also inserted into the opening provided in the center of the corresponding two sides of the second support portion 14 having the B shape, and the second support portion. 14 is provided on the base 16 so as to be rotatable about the second pin 15 as a rotation axis.

  The second support portion 14 has an opening at the center of the other two sides, and the first pins 13 are inserted into openings provided at both ends corresponding to the U-shaped first support portion 12. Thus, the first support portion 12 is rotatably provided with the first pin 13 as the rotation axis.

  The lever 10 is provided perpendicular to the longitudinal direction of the first support portion 12, and the knob 10 is provided at the other end facing the end where the counter magnet 2 is provided. With such a configuration, the counter magnet 2 can be freely moved in the two-dimensional direction via the knob 10 and the lever 11 to indicate a two-dimensional position.

  In addition, an output voltage (described later) output from the MR sensor 3 of the joystick 1 is transmitted to the determination unit 5, and the determination unit 5 calculates the position instructed by the lever 11 based on the received output voltage. A signal representing the result is transmitted to the ECU 6 of the vehicle, and the ECU 6 controls the pointer displayed on the display unit 7 based on the received signal indicating the position as an example. In addition, the structure of the joystick 1 is not limited to this, You may use for the apparatus corresponded to a known joystick.

(Configuration of counter magnet 2)
The counter magnet 2 is magnetized in a direction perpendicular to the two-dimensional direction in which the tilting operation is performed. As an example, the counter magnet 2 has a cylindrical shape and is formed of a permanent magnet such as an alnico magnet, a ferrite magnet, or a neodymium magnet. The counter magnet 2 is arranged so that the N pole 21 side faces the MR sensor 3. The shape of the counter magnet 2 is not limited to this, and may be a shape that can change the direction of the bias magnetic field, such as a spherical shape and a rectangular shape. Further, the N pole 21 and the S pole 20 of the counter magnet 2 may be interchanged. At this time, it is necessary to change the magnetization direction of the bias magnet 4. This is because when the opposing magnetic poles are the same pole, the magnetic field 8 repels each other, so that the magnetic vector 8 has a component that is more parallel to the detection surface of the MR sensor 3 and detects the change in angle. It is easy.

(Configuration of MR sensor 3)
FIG. 3 is a schematic diagram of the MR element according to the first embodiment of the present invention. In the following, the angle θ represents an angle from the length direction of the first and second MR elements 35 and 36.

  The MR sensor 3 includes first to fourth half bridges 31 to 31 having first and second MR elements 35 and 36 made of a thin film mainly composed of a ferromagnetic metal such as NiFe permalloy, NiCo, and FeCo alloy. 34 is arranged on each vertex of the virtual cross and formed on the substrate 30. Further, the first half bridge 31 and the second half bridge 32 are arranged to face each other with the third half bridge 33 and the fourth half bridge 34 facing each other.

  Taking the first MR element 35 shown in FIG. 3 as an example, the first and second MR elements 35 and 36 have a plurality of magnetic sensing portions 3A having a folded shape. In FIG. 3, it is assumed that the horizontal axis is the x-axis, the vertical axis is the y-axis, and the magnetic sensitive part 3A of the first MR element 35 is perpendicular to the x-axis. When the magnetic vector 8 crosses from the direction (θ = 0) perpendicular to the magnetic sensing part 3A, the magnetoresistance value of the first MR element 35 is minimized. On the other hand, when the magnetic vector 8 crosses from a direction (θ = 90 °) parallel to the magnetic sensing part 3A, the magnetoresistance value of the first MR element 35 is maximized. Since the second MR element 36 has the same configuration and function as the first MR element 35, description thereof is omitted.

  In the first half bridge 31, as shown in FIG. 2B, the first MR element 35 and the second MR element 36 form a half bridge circuit with their magnetic sensing directions orthogonal to each other. The length direction of the first MR element 35 is inclined 45 ° with respect to the x-axis. (The length direction of the second MR element 36 is inclined by −45 ° with respect to the x-axis.) Midpoint potential of the first MR element 35 and the second MR element 36 in the first half bridge 31. Is output as an output voltage V1 based on the ratio of the respective magnetoresistance values. Like the first half bridge 31, the second to fourth half bridges 32 to 34 have first and second MR elements 35 and 36, and output output voltages V2, V3, and V4, respectively. .

As an example, as shown in FIG. 2B, the first to fourth half bridges 31 to 34 receive the applied voltage _{Vcc and} are electrically connected to a ground circuit (not shown).

  Detection of the movement of the counter magnet 2 in the horizontal direction (detection in the x-axis direction) is performed by the second and fourth half bridges 32 and 34 facing each other, and detection of the movement in the vertical direction is performed by the first and third facing each other. Half bridges 31 and 33.

(About the bias magnet 4)
The bias magnet 4 has a cylindrical shape and is formed of a permanent magnet such as an alnico magnet, a ferrite magnet, or a neodymium magnet. Further, as shown in FIG. 2A, the bias magnet 4 has a radial shape that extends outward from the center with respect to the detection surface of the MR sensor 3 (the surface on which the first to fourth half bridges 31 to 34 are disposed). The bias magnetic field is applied to the MR sensor 3. The magnetic vector 8 visualizes the direction and magnitude of the magnetic field lines of the magnetic field on the detection surface of the MR sensor 3. The joystick 1 may be configured without the bias magnet 4, and the shape of the bias magnet 4 is not limited to this.

(About judgment part 5)
For example, the determination unit 5 calculates (V3−V1) based on the output voltages V1 and V3 output from the first and third half bridges 31 and 33 facing each other. Similarly, the determination unit 5 calculates (V4−V2) based on the output voltages V2 and V4 output from the opposing second and fourth half bridges 32 and 34. The determination unit 5 stores the positive / negative combination of (V3-V1) and (V4-V2), and determines a plurality of positions based on the combination. Moreover, since the 1st-4th half bridges 31-34 are installed apart from MR sensor 3, the error of the output voltage resulting from position shift at the time of installation can be controlled. This is because the angle of the magnetic vector 8 with respect to the first and second MR elements 35 and 36 increases or decreases by the same angle even if a positional deviation occurs.

(Operation)
Hereinafter, the operation of the joystick 1 according to the first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3 and FIGS.

  FIG. 4 is a view showing positions for performing the tilting operation according to the first embodiment of the present invention, and FIGS. 5 and 6 are output waveforms of the MR sensor according to the first embodiment of the present invention. FIG. N and P <b> 1 to P <b> 8 shown in FIG. 4 represent an example of a two-dimensional position that can be designated with the joystick 1. FIG. 5 is a graph of (V3-V1) and (V4-V2) when the lever 11 is tilted from the position N in the x-axis direction. FIG. 6 is a graph showing the lever 11 at 30 ° in the x-axis direction. It is a graph of (V3-V1) and (V4-V2) when tilting in the y-axis direction while tilting. (V4-V2) is an output voltage in the x-axis direction, and (V3-V1) is an output voltage in the y-axis direction. Also, the following description is based on simulated results.

(Position N detection operation)
FIG. 7A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 7B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position N shown in FIG. 4 is shown.

  When the counter magnet 2 is in the position N, the first and third half bridges 31 and 33 have a magnetic vector 8 parallel to the x axis, and the second and fourth half bridges 32 and 34 have a y axis. A magnetic vector 8 parallel to is traversed. As shown in FIG. 5 (b), the angles of the first and second MR elements 35, 36 and the magnetic vector 8 are 45 °, and the magnetoresistance values are the same. Therefore, the output voltages V1, V2, V3 and V4 are zero.

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Are both zero (hereinafter referred to as (0, 0)), the ECU 6 determines that the counter magnet 2 is in the position N and receives a signal indicating the position from the determination unit 5. Performs processing to keep the displayed pointer in its current state.

(Position P1 detection operation)
FIG. 8A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 8B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P1 shown in FIG. 4 is shown. The length of the magnetic vector 8 represents the approximate strength of the detection surface component.

  When the lever 11 is tilted to the position P1, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity of the fourth half bridge 34. As a result, the detection surface component of the magnetic vector 8 becomes small in a strong place. The direction of the magnetic vector 8 changes as shown in FIG.

  The output voltage from the half bridge is represented by a ratio of resistance values, and in this embodiment, is proportional to the magnetoresistance value of the second MR element 36. Therefore, in the first half bridge 31, the magnetic vector 8 crosses perpendicularly to the magnetic sensing part 3A of the second MR element 36 (low magnetic resistance value), and in the third half bridge 33, Since the magnetic vector 8 crosses in parallel (the magnetic resistance value is large), (V3-V1) is positive (+). Hereafter, the magnetoresistance value when the angle between the bias magnetic field and the magnetic sensing part 3A is 45 ° is “middle magnetoresistance value”, and the magnetoresistance value is larger than this with “middle magnetoresistance value” as a reference. "Magnetic resistance value" is sometimes described as small, and "Magnetic resistance value is small" when small.

  On the other hand, since the magnetic vector 8 crosses the second and fourth half bridges 32 and 34 at about 45 ° with respect to the magnetic sensing portion 3A, (V4−V2) becomes zero, and the combination of (+, 0) and Become.

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (+, 0), it is determined that the counter magnet 2 is in the position P1, and a predetermined process is performed via the ECU 6.

(Position P2 detection operation)
FIG. 9A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 9B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P2 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P2, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity between the first half bridge 31 and the fourth half bridge 34. As a result, the magnetic vector 8 is The direction changes as shown in 9 (a).

  The first half bridge 31 crosses the magnetic vector 8 at a near-perpendicular angle with respect to the magnetic sensing portion 3A of the second MR element 36 (small magnetic resistance value), and the third half bridge 33 Since the magnetic vector 8 crosses at an angle close to parallel (large magnetoresistance value), (V3−V1) is positive (+).

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at an angle close to parallel to the magnetic sensing portion 3A (large magnetic resistance value), and the fourth half bridge 34 has an angle near vertical. Since the magnetic vector 8 crosses (small magnetic resistance value), (V4−V2) becomes negative (−) and becomes a combination of (+, −).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (+, −), it is determined that the counter magnet 2 is in the position P2, and predetermined processing is performed via the ECU 6.

(Detection operation for position P3)
FIG. 10A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 10B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P3 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P3, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity of the first half bridge 31, and as a result, the magnetic vector 8 has a direction as shown in FIG. Changes.

  The magnetic vector 8 crosses the first half bridge 31 at 45 ° with respect to the magnetic sensing portion 3A of the second MR element 36 (middle magnetoresistance value), and the third half bridge 33 has 45 Since the magnetic vector 8 crosses (in the magnetic resistance value) at (°), (V3-V1) becomes zero.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 in parallel to the magnetic sensing part 3A (large magnetic resistance value), and the magnetic vector 8 crosses the fourth half bridge 34 vertically ( Therefore, (V4−V2) becomes negative and becomes a combination of (0, −).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (0, −), it is determined that the counter magnet 2 is in the position P3, and a predetermined process is performed via the ECU 6.

(Detection operation for position P4)
FIG. 11A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 11B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P4 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P4, the magnetic field generated by the counter magnet 2 becomes stronger in the vicinity between the first half bridge 31 and the second half bridge 32. As a result, the magnetic vector 8 is The direction changes as shown in FIG.

  The first half bridge 31 crosses the magnetic vector 8 at a near-parallel angle with respect to the magnetic sensing part 3A of the second MR element 36 (large magnetic resistance value), and the third half bridge 33 Since the magnetic vector 8 crosses at an angle close to perpendicular (small magnetic resistance value), (V3-V1) is negative.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at an angle close to parallel to the magnetic sensing portion 3A (large magnetic resistance value), and the fourth half bridge 34 has an angle near vertical. Since the magnetic vector 8 crosses (small magnetic resistance value), (V4−V2) becomes negative and becomes a combination of (−, −).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (−, −), it is determined that the counter magnet 2 is in the position P4, and a predetermined process is performed via the ECU 6.

(Detection operation for position P5)
FIG. 12A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 12B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P5 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P5, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity of the second half bridge 32, and as a result, the magnetic vector 8 has a direction as shown in FIG. Changes.

  The first half bridge 31 crosses the magnetic vector 8 in parallel with the magnetic sensing part 3A of the second MR element 36 (large magnetic resistance value), and the third half bridge 33 is perpendicular to the magnetic sensing part 3A. Since the magnetic vector 8 crosses (small magnetic resistance value), (V3-V1) becomes negative.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at 45 ° with respect to the magnetic sensing portion 3A (middle magnetoresistance value), and the magnetic vector 8 crosses the fourth half bridge 34 at 45 °. Since it crosses (in the magnetoresistance value), (V4−V2) becomes zero, which is a combination of (−, 0).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (−, 0), it is determined that the counter magnet 2 is in the position P5, and a predetermined process is performed via the ECU 6.

(Detection operation for position P6)
FIG. 13A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 13B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P6 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P6, the magnetic field generated by the counter magnet 2 becomes stronger in the vicinity between the second half bridge 32 and the third half bridge 33. As a result, the magnetic vector 8 is The direction changes as shown in FIG.

  The first half bridge 31 crosses the magnetic vector 8 at a near-parallel angle with respect to the magnetic sensing part 3A of the second MR element 36 (large magnetic resistance value), and the third half bridge 33 Since the magnetic vector 8 crosses at an angle close to perpendicular (small magnetic resistance value), (V3-V1) is negative.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at a near-perpendicular angle with respect to the magnetic sensing part 3A (small magnetic resistance value), and the fourth half-bridge 34 has a near-parallel angle. Since the magnetic vector 8 crosses (the magnetic resistance value is large), (V4−V2) becomes positive and becomes a combination of (−, +).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (−, +), it is determined that the counter magnet 2 is in the position P6, and a predetermined process is performed via the ECU 6.

(Detection operation for position P7)
FIG. 14A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 14B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P7 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P7, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity of the third half bridge 33, and as a result, the magnetic vector 8 has a direction as shown in FIG. Changes.

  The magnetic vector 8 crosses the first half bridge 31 at 45 ° with respect to the magnetic sensing portion 3A of the second MR element 36 (middle magnetoresistance value), and the third half bridge 33 has 45 Since the magnetic vector 8 crosses (in the magnetic resistance value) at (°), (V3-V1) becomes zero.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at a near-perpendicular angle with respect to the magnetic sensing part 3A (small magnetic resistance value), and the fourth half-bridge 34 has a near-parallel angle. Since the magnetic vector 8 crosses (the magnetic resistance value is large), (V4−V2) becomes positive and becomes a combination of (0, +).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (0, +), it is determined that the counter magnet 2 is in the position P7, and a predetermined process is performed via the ECU 6.

(Detection operation for position P8)
FIG. 15A is a top view of the MR sensor according to the first embodiment of the present invention, and FIG. 15B is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. The case where the lever 11 is operated to the position P8 shown in FIG. 4 is shown.

  When the lever 11 is tilted to the position P8, the magnetic field generated by the counter magnet 2 becomes strong in the vicinity between the third half bridge 33 and the fourth half bridge 34. As a result, the magnetic vector 8 is The direction changes as shown in FIG.

  The first half bridge 31 crosses the magnetic vector 8 at a near-perpendicular angle with respect to the magnetic sensing portion 3A of the second MR element 36 (small magnetic resistance value), and the third half bridge 33 Since the magnetic vector 8 crosses at an angle close to parallel (large magnetoresistance value), (V3-V1) is positive.

  On the other hand, the magnetic vector 8 crosses the second half bridge 32 at a near-perpendicular angle with respect to the magnetic sensing part 3A (small magnetic resistance value), and the fourth half-bridge 34 has a near-parallel angle. Since the magnetic vector 8 crosses (the magnetic resistance value is large), (V4−V2) becomes positive and becomes a combination of (+, +).

  The determination unit 5 determines the difference between the output voltages from the first and third half bridges 31, 33 (V3-V1) and the difference between the output voltages from the second and fourth half bridges 32, 34 (V4-V2). ) Is a combination of (+, +), it is determined that the counter magnet 2 is at the position P7, and a predetermined process is performed via the ECU 6.

  As shown in FIG. 5, the detection of the plurality of positions described above can be performed stably by obtaining the detection result in the x-axis direction and the detection result in the y-axis independently, in other words, by reducing crosstalk. . As an example, when the lever 11 is tilted by about 30 ° in the x-axis direction and then tilted by about 30 ° in the y-axis direction, the output voltage in the x-axis direction and the y-axis direction as shown in FIG. The output voltage can be obtained with little crosstalk. In addition to the position detection described above, the output signal from the joystick 1 is analog output for the tilting operation as shown in FIGS. 5 and 6 and so on, so that an arbitrary two-dimensional position (position) can be obtained. Since it can be detected, the joystick 1 is not limited to the above positions (N, P1 to P8), and can be used as a continuously variable controller such as a game controller or a pointing device. It can also be used for multidirectional switches.

(effect)
According to the first embodiment described above, since the joystick 1 can detect the movement of the counter magnet 2 in the x-axis direction and the y-axis direction with little crosstalk, the two-dimensional position can be stabilized. Can be detected. Further, the joystick 1 has a high durability because it can instruct the position and the like without contact.

[Second Embodiment]
(Configuration of joystick 1)
FIG. 16 is an equivalent circuit diagram of the MR sensor according to the second embodiment of the present invention, and FIG. 17 is an angle converted from the angle of the lever in the x direction according to the second embodiment of the present invention. It is a figure showing the relationship.

  This embodiment is different from the above-described first embodiment in the configuration of the MR sensor 3. The MR sensor 3 includes a fifth half bridge 31a obtained by rotating the first half bridge 31 by 90 ° counterclockwise to a position where the directions of the magnetic vectors 8 across the first half bridge 31 are approximately equal to each other. A magnetic vector 8 crossing the third half bridge 33 and a sixth half bridge 32a obtained by rotating the second half bridge 32 by 90 ° counterclockwise to a position where the directions of the magnetic vectors 8 crossing the half bridge 32 are approximately equal. The seventh half bridge 33a obtained by rotating the third half bridge 33 by 90 ° in the clockwise direction at a position where the directions of the magnetic vectors 8 are approximately equal to each other and the direction of the magnetic vector 8 crossing the fourth half bridge 34 are approximately equal to the fourth direction. And an eighth half bridge 34a obtained by rotating the half bridge 34 clockwise by 90 °. The output voltages output from the fifth to eighth half bridges 31a to 34a are V5 to V8.

(Operation)
The MR sensor is known to change its resistance value not only by a magnetic field but also by temperature. In addition, the output voltage may be affected by the difference in sensitivity due to the manufacturing error of the MR sensor. Therefore, in order to obtain a relationship between an angle closer to linearity (the angle between the magnetic field and the magnetic sensing portion 3A) and the output voltage, it is necessary to perform temperature correction and sensitivity variation correction.

  The determination unit 5 is based on output voltages V2, V4, V6, and V8 output from the second, fourth, sixth, and eighth half bridges 32, 34, 32a, and 34a that detect movement of the counter magnet 2 in the x-axis direction. As an example, angle conversion described later is performed on X1 (= V4−V2) and X2 (= V8−V6) to calculate an angle formed by the magnetic sensing portion 3A and the bias magnetic field. For example, the determination unit 5 calculates [Arctan (X2 / X1)] / 2 as angle conversion based on X1 and X2, and calculates the angle of the magnetic vector 8 with respect to the x-axis.

  The determination unit 5 outputs the output voltages V1, V3, V5, and V7 output from the first, third, fifth, and seventh half bridges 31, 33, 31a, and 33a that detect the movement of the counter magnet 2 in the y-axis direction. As an example, angle conversion is performed on Y1 (= V3-V1) and Y2 (= V7-V5). The determination unit 5 calculates [Arctan (Y2 / Y1)] / 2 as an example based on Y1 and Y2, and calculates the angle of the magnetic vector 8 with the y-axis. The magnetic resistance value depends on the magnetic vector 8 and the angle θ of the magnetic sensing portion 3A, but does not depend on the direction of the direction when the angle θ is the same, and therefore the angle-converted value is divided by two. The relationship between the angle converted by the above method and the angle of tilting operation of the lever 11 in the x-axis direction is close to linear as shown in FIG. And the movement of the counter magnet 2 in the y-axis direction can be detected.

  As described above, angle conversion is performed by combining the output voltages of the first to eighth half bridges 31 to 34, 31a to 34a, and the installation angle of each half bridge, that is, the phase of the output voltage is changed. The reason for this is to suppress detection errors due to variations in installation positions, errors due to changes in magnetoresistance values due to temperature, and errors due to differences in sensitivity. The function whose angle has been converted by the determination unit 5 is a function representing a circle, and the error thereof corresponds to the size of the radius of the circle, and therefore does not affect the angle. Therefore, the MR sensor 3 can detect the position stably by having the above-described configuration, and, as shown in the first embodiment, a plurality of positions can be obtained even when the half bridge is arranged. Since it can be detected, redundancy can be ensured.

(effect)
According to the second embodiment described above, the joystick 1 can detect the movement of the counter magnet 2 in the x-axis direction and the y-axis direction with little crosstalk, so the two-dimensional position can be stabilized. Can be detected. In addition, the joystick 1 can ensure redundancy.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from or changing the technical idea of the present invention.

It is the schematic of the joystick which concerns on the 1st Embodiment of this invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. 1 is a schematic diagram of an MR element according to a first embodiment of the present invention. It is the figure shown about the position which performs tilting operation which concerns on the 1st Embodiment of this invention. It is a figure showing the output waveform of MR sensor concerning a 1st embodiment of the present invention. It is a figure showing the output waveform of MR sensor concerning a 1st embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. (A) is a top view of the MR sensor according to the first embodiment of the present invention, and (b) is an equivalent circuit diagram of the MR sensor according to the first embodiment of the present invention. FIG. 6 is an equivalent circuit diagram of an MR sensor according to a second embodiment of the present invention. It is a figure showing the relationship between the angle of the lever of the x direction which concerns on the 2nd Embodiment of this invention, and the angle which carried out angle conversion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Joystick, 2 ... Counter magnet, 3 ... MR sensor, 3A ... Magnetosensitive part, 4 ... Bias magnet, 5 ... Judgment part, 6 ... ECU, 7 ... Display part, 8 ... Magnetic vector, 10 ... Knob, 11 ... Lever, 12 ... 1st support part, 13 ... 1st pin, 14 ... 2nd support part, 15 ... 2nd pin, 16 ... Base, 16a ... Convex part, 20 ... S pole, 21 ... N pole , 30 ... substrate, 31-34 ... first to fourth half bridges, 31a to 34a ... fifth to eighth half bridges, 35 ... first MR element, 35a ... third MR element, 36 ... th 2 MR elements, 36a ... 4th MR element, 40 ... N pole, 41 ... S pole, V1-V8 ... output voltage, _Vcc ... applied voltage, θ ... angle, N, P1-P8 ... position

Claims (4)

An operation unit for instructing a two-dimensional position by performing a tilting operation;
A counter magnet provided in the operation unit and magnetized in a direction perpendicular to a direction in which the tilting operation is performed;
The first magnetoresistive element is composed of first and second magnetoresistive elements that are perpendicular to each other in the magnetosensitive direction, and the length direction of the first magnetoresistive element is inclined by 45 ° with respect to one direction of the two-dimensional position. The half-bridge circuit in which the length direction of the magnetoresistive element 2 is inclined by −45 ° is arranged in the same direction as the first to fourth half-bridges at each vertex of the cross, and the above-described tilt operation is performed. Based on the change in the direction of the magnetic field of the counter magnet, the first output voltage is output from the first and third half bridges facing each other, and the second output voltage is output from the second and fourth half bridges facing each other. A magnetic sensor
A detector that detects the two-dimensional position instructed by the tilting operation based on the first and second output voltages output from the magnetic sensor;
A position sensor comprising:   The position sensor according to claim 1, wherein the detection unit detects the two-dimensional position based on a positive / negative combination of the first and second output voltages output from the magnetic sensor. An operation unit for instructing a two-dimensional position by performing a tilting operation;
A counter magnet provided in the operation unit and magnetized in a direction perpendicular to a direction in which the tilting operation is performed;
A bias magnet that generates a bias magnetic field, and is disposed so that a surface facing the counter magnet is the same as the corresponding pole of the counter magnet;
The first magnetoresistive element is composed of first and second magnetoresistive elements that are perpendicular to each other in the magnetosensitive direction, and the length direction of the first magnetoresistive element is inclined by 45 ° with respect to one direction of the two-dimensional position. The half-bridge circuit in which the length direction of the magnetoresistive element 2 is inclined by −45 ° is arranged in the same direction as the first to fourth half-bridges at each vertex of the cross, and the above-described tilt operation is performed. Magnetism for outputting a first output voltage from the first and third half bridges facing each other and a second output voltage from the second and fourth half bridges facing each other based on a change in the direction of the bias magnetic field. A sensor,
A detection unit for detecting the two-dimensional position indicated by the tilting operation based on a positive / negative combination of the first and second output voltages output from the magnetic sensor;
A position sensor characterized by comprising The magnetic sensor forms a first full bridge together with the first half bridge using a fifth half bridge obtained by rotating the first half bridge by 45 ° counterclockwise, and the second half bridge. A second half bridge was formed together with the second half bridge using a sixth half bridge having the bridge rotated 45 ° counterclockwise, and the third half bridge was rotated 45 ° clockwise. A third full bridge is formed with the third half bridge using a seventh half bridge, and the fourth half bridge is rotated by 45 ° clockwise using the eighth half bridge. With the other half bridge to form a fourth full bridge,
Detector, the position according to claim 3, characterized in Rukoto issuing test the pre SL 2-dimensional positions by performing angle converter based on the output voltage output from the first to fourth full bridge Sensor.

Images