Position detection device, optical device, position detection method, and position detection program

Abstract

To provide a position detection device for suppressing an influence on variation in characteristics and / or assembly accuracy.SOLUTION: A position detection device includes: a first sensor and a second sensor that are provided so as to face a magnet disposed at a reference position in a first direction and detect a magnetic flux generated by the magnet, the first sensor and the second sensor detecting a change in the magnetic flux based on a change in relative position between the first sensor and the magnet and between the second sensor and the magnet in a second direction intersecting the first direction; an adjustment unit that adjusts an amplification factor of a first detection signal detected by the first sensor and an amplification factor of a second detection signal detected by the second sensor in accordance with movement of the first sensor and the second sensor or the magnet; and a calculation unit that calculates either a ratio of the sum of the first detection signal and the second detection signal to the difference between the first detection signal and the second detection signal, or a ratio of the difference to the sum.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a position detection device, an optical device, a position detection method, and a position detection program. [Background technology]

[0002] Patent Document 1 states that "to provide a position detection device that suppresses the effects of variations in the characteristics of magnets and magnetic sensors and assembly precision." [Prior art document] [Patent documents] [Patent Document 1] JP 2004-348173 A Summary of the Invention

[0003] In a first aspect of the present invention, there is provided a position detection device comprising: a first sensor and a second sensor that are provided to face a magnet placed at a reference position in a first direction and detect a magnetic flux from the magnet, the first sensor and the second sensor detecting a change in the magnetic flux based on a change in the relative position between the first sensor and the second sensor and the magnet in a second direction intersecting the first direction, an adjustment unit that adjusts an amplification factor of a first detection signal detected by the first sensor and an amplification factor of a second detection signal detected by the second sensor in accordance with movement of the first sensor and the second sensor or the magnet, and a calculation unit that calculates a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal, or a ratio between the difference and the sum.

[0004] The adjustment unit may adjust the amplification factor based on relative positions in the first direction between the first sensor, the second sensor, and the magnet.

[0005] In any of the position detection devices described above, the difference between the first detection signal and the second detection signal may be the difference between the first detection signal amplified with an amplification factor adjusted by the adjustment unit and the second detection signal amplified with an amplification factor adjusted by the adjustment unit. The adjustment unit may adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal based on the difference between the first detection signal amplified with the adjusted amplification factor and the second detection signal amplified with the adjusted amplification factor. The calculation unit may calculate a ratio between the sum of the first detection signal and the second detection signal and the difference between the first detection signal and the second detection signal.

[0006] In any of the position detection devices described above, the adjustment unit may adjust the amplification factor based on the difference between the first detection signal amplified with the adjusted amplification factor and the second detection signal amplified with the adjusted amplification factor, and the current amplification factor in the adjustment unit.

[0007] In any of the position detection devices described above, the adjustment section may adjust the amplification factor based on a difference between the first detection signal and the second detection signal.

[0008] In any of the position detection devices described above, the sum of the first detection signal and the second detection signal may be the sum of the first detection signal amplified with an amplification factor adjusted by the adjustment unit and the second detection signal amplified with an amplification factor adjusted by the adjustment unit. The adjustment unit may adjust the amplification factor based on the sum of the first detection signal amplified with the adjusted amplification factor and the second detection signal amplified with the adjusted amplification factor. The calculation unit may calculate a ratio between a difference between the first detection signal and the second detection signal and the sum of the first detection signal and the second detection signal.

[0009] In any of the position detection devices described above, the adjustment unit may adjust the amplification factor based on the sum of the first detection signal amplified with the adjusted amplification factor and the second detection signal amplified with the adjusted amplification factor, and the current amplification factor in the adjustment unit.

[0010] In any of the position detection devices described above, the adjustment section may adjust the amplification factor based on the sum of the first detection signal and the second detection signal.

[0011] Any of the position detection devices described above may further include a third sensor that detects the relative position in the first direction.

[0012] In any of the position detection devices described above, the adjustment section may adjust the amplification factor based on a rate of change of the first detection signal or the second detection signal with respect to a change in the relative position in the second direction.

[0013] In any of the above position detection devices, the change in the relative position in the second direction may be the difference between a target position of the magnet relative to the first sensor and the second sensor in the second direction and a current position of the magnet relative to the first sensor and the second sensor in the second direction.

[0014] Any of the position detection devices described above may further include an AD converter that converts a first detection signal, the signal level of which is within a predetermined first range, into a first digital signal and converts a second detection signal, the signal level of which is within a predetermined second range, into a second digital signal. The adjustment unit may adjust the amplification factor based on the magnitude of the first range or the second range.

[0015] Any of the position detection devices described above may further include an amplifier that amplifies the first detection signal and the second detection signal. The adjustment unit may adjust the amplification factor of the amplifier to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal.

[0016] In any of the position detection devices described above, the adjustment section may adjust the amplification factor of the first sensor and the amplification factor of the second sensor to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal.

[0017] Any of the position detection devices described above may further include an AD converter that converts the first detection signal into a first digital signal and converts the second detection signal into a second digital signal. The adjustment unit may adjust the amplification factor of the AD converter to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal.

[0018] Any of the position detection devices described above may further include an AD converter that converts the first detection signal into a first digital signal and converts the second detection signal into a second digital signal. The adjustment unit may adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal by adjusting a reference voltage of the AD converter.

[0019] In a second aspect of the present invention, there is provided an optical device. The optical device includes a lens arranged in a relative position in the second direction relative to a first sensor and a second sensor, the lens being in the same relative position as the relative position in the second direction, a drive unit that drives the lens, and any one of the position detection devices described above. The first sensor and the second sensor detect the relative positions of the first sensor and the second sensor and the magnet in the second direction. The drive unit drives the lens based on the relative position of the magnet in the second direction detected by the first sensor and the second sensor.

[0020] In a third aspect of the present invention, there is provided a position detection method, comprising: an adjustment step in which an adjustment unit adjusts an amplification factor of a first detection signal detected by the first sensor that detects a change in magnetic flux based on a change in relative position between the first sensor, the second sensor, and the magnet in a second direction that intersects the first direction, and an amplification factor of a second detection signal detected by the second sensor that detects the change in magnetic flux, according to movement of the first sensor and the second sensor or the magnet; and a calculation step in which a calculation unit calculates a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal, or a ratio between the difference and the sum.

[0021] In a fourth aspect of the present invention, there is provided a position detection program, which causes a computer to execute an adjustment step of adjusting an amplification factor of a first detection signal detected by a first sensor that detects a change in magnetic flux based on a change in relative position between the first sensor and the second sensor and the magnet in a second direction that intersects the first direction, and an amplification factor of a second detection signal detected by the second sensor that detects the change in magnetic flux, in accordance with movement of the first sensor and the second sensor or the magnet, and a calculation step of calculating a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal, or a ratio between the difference and the sum.

[0022] The above summary of the invention does not list all of the features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0023] [Figure 1A] FIG. 1 illustrates an example of an optical device 200 according to an embodiment of the present invention. [Figure 1B] This is an example of a case where the distance d has changed from the distance d1 in the optical device 200 of FIG. 1A. [Diagram 2] 1B is a diagram showing the optical device 200 of FIG. 1A as viewed from the X-axis direction. [Diagram 3] FIG. 1 illustrates an example of a position detection device 100 according to an embodiment of the present invention. [Figure 4] 13 is a diagram showing an example of a first detection signal S1 when the distance d is a distance d1. FIG. [Diagram 5] 13 is a diagram showing an example of a first detection signal S1 when the distance d is a distance d2 (>distance d1). FIG. [Figure 6] 1 shows an example of measurement results of an input voltage Vin to the amplifier 40, noise N of the first sensor 10 and the second sensor 12, and a signal Sm amplified by the amplifier 40. [Figure 7]1 shows an example of measurement results of an input voltage Vin to the amplifier 40, noise N of the first sensor 10 and the second sensor 12, and a signal Sm amplified by the amplifier 40. [Figure 8] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 9] FIG. 9 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d1 (the case of FIG. 1A) in the example of FIG. 8. [Figure 10] FIG. 9 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d2 (>distance d1) (case of FIG. 1B) in the example of FIG. 8. [Figure 11] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 12] FIG. 12 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d1 (the case of FIG. 1A) in the example of FIG. 11. [Figure 13] FIG. 12 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d2 (>distance d1) (case of FIG. 1B) in the example of FIG. 11. [Figure 14] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 15] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 16] In the example of FIG. 8, this is a diagram showing an example of the relationship between the first detection signal S1' and the second detection signal S2' and the relative position in the second direction when the distance d is the distance d1 (the case of FIG. 1A). [Figure 17] 8, this is a diagram showing an example of the relationship between the first detection signal S1' and the second detection signal S2' and the relative position in the second direction when the distance d is distance d2 (>distance d1) (case of FIG. 1B). [Figure 18] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 19] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 20] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 21] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 22] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 23] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 24] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Diagram 25] 2 is a diagram illustrating a first range of the first AD converter 52. FIG. [Figure 26] FIG. 2 is a diagram illustrating another example of the position detection device 100 according to an embodiment of the present invention. [Figure 27] 4 is a flowchart illustrating an example of a position detection method according to an embodiment of the present invention. [Figure 28] 11 is a flowchart illustrating another example of a position detection method according to an embodiment of the present invention. [Figure 29] 11 is a flowchart illustrating another example of a position detection method according to an embodiment of the present invention. [Diagram 30] FIG. 22 illustrates an example of a computer 2200 in which a position detection device 100 according to an embodiment of the present invention may be implemented in whole or in part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] 1A is a diagram showing an example of an optical device 200 according to an embodiment of the present invention. The optical device 200 includes a position detection device 100, a lens 110, and a driving unit 130. The optical device 200 may include a magnet 120 and a lens support unit 140. The optical device 200 is, for example, a smartphone, a tablet, or the like. When the optical device 200 is a smartphone, a tablet, or the like, the smartphone, tablet, or the like has a built-in lens 110.

[0026] The optical device 200 may include a housing 160, a first member 162 of the housing 160, and a second member 164 of the housing 160. The first member 162 may be a plate-like member having a plate surface in the XZ plane. The second member 164 may be a plate-like member having a plate surface in the XY plane.

[0027] The position detection device 100 includes a first sensor 10 and a second sensor 12. In this example, the position detection device 100 is disposed on a plate surface of a plate-shaped first member 162. The drive unit 130 drives the lens 110 based on the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120.

[0028] The position detection device 100 may or may not include an image sensor 14. In the example of FIG. 1A, the position detection device 100 includes an image sensor 14. The image sensor 14 may be disposed at a position overlapping with the lens 110 when viewed from the Z-axis direction. The position of the image sensor 14 is indicated by a dashed line in FIG. 1A. When the position detection device 100 does not include the image sensor 14, the image sensor 14 may be disposed outside the position detection device 100. The image sensor 14 is, for example, a CMOS sensor or a CCD sensor.

[0029] In this specification, technical matters may be described using orthogonal coordinate axes of the X-axis, Y-axis, and Z-axis. In this specification, the direction from the position detection device 100 to the magnet 120 is defined as the Y-axis direction, and the direction from the second sensor 12 to the first sensor 10 is defined as the X-axis direction. The direction from the N pole to the S pole of the magnet 120 may be the X-axis direction. In this specification, the direction perpendicular to the XY plane is defined as the Z-axis direction. In this specification, the Y-axis direction is defined as the first direction, and the X-axis direction is defined as the second direction.

[0030] The first sensor 10 and the second sensor 12 detect a magnetic flux generated by the magnet 120. The first sensor 10 and the second sensor 12 are, for example, a Hall element or an MR (Magneto Resistive) element. The first sensor 10 and the second sensor 12 detect a change in the magnetic flux based on a change in the relative position between the first sensor 10 and the second sensor 12 and the magnet 120 in the second direction.

[0031] The lens support section 140 supports the lens 110. The optical device 200 may be provided with a recess 150. When the optical device 200 is a smartphone, the recess 150 may be a depression provided in a housing 160 of the smartphone, and may be a depression recessed in a direction from the surface of the housing 160 toward the inside (the Z-axis direction in the example of FIG. 1A ).

[0032] The first sensor 10 and the second sensor 12 are provided to face the magnet 120 in a first direction. The first sensor 10 and the second sensor 12 face the magnet 120 in the first direction means that the direction from the first sensor 10 to a position of the magnet 120 has a component in the first direction, and the direction from the second sensor 12 to a position of the magnet 120 has a component in the first direction. The first sensor 10 and the second sensor 12 may be arranged at a position overlapping at least a part of the magnet 120 when viewed from the first direction. The first sensor 10 may be arranged at a position overlapping at least a part of one of the S pole and the N pole of the magnet 120 when viewed from the first direction. The second sensor 12 may be arranged at a position overlapping at least a part of the other of the S pole and the N pole of the magnet 120 when viewed from the first direction.

[0033] The magnet 120 is disposed at a reference position. The reference position is a position where the position detection device 100 can detect the relative position between the magnet 120 and the first sensor 10 and the second sensor 12 by the first sensor 10 and the second sensor 12 detecting a change in magnetic flux caused by the magnet 120. As described later, the relative position between the magnet 120 and the first sensor 10 and the second sensor 12 can change in a first direction and can change in a second direction. In order for the position detection device 100 to detect the relative position between the magnet 120 and the first sensor 10 and the second sensor 12 in the second direction, it is preferable that the S pole and the N pole of the magnet 120 are disposed between the first sensor 10 and the second sensor 12 in the second direction. The magnet 120 may be a permanent magnet or an electromagnet.

[0034] The lens 110 is disposed at a relative position with respect to the first sensor 10 and the second sensor 12 that is the same as the relative positions in the second direction between the first sensor 10 and the second sensor 12 and the lens 110. That is, in the second direction, the relative positions between the first sensor 10 and the second sensor 12 and the lens 110 are the same as the relative positions between the first sensor 10 and the second sensor 12 and the magnet 120. When the magnet 120 moves in the second direction, the magnet 120 and the lens 110 move together in the second direction.

[0035] When the magnet 120 moves in the first direction, the amount of movement in the first direction of the magnet 120 and the first and second sensors 10 and 12 is the same as the amount of movement in the first direction of the lens 110 and the first and second sensors 10 and 12. When the magnet 120 moves in the first direction, the magnet 120 and the lens 110 move together in the first direction.

[0036] The driving unit 130 drives the lens 110. The first sensor 10 and the second sensor 12 detect the relative positions in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The driving unit 130 drives the lens 110 based on the relative positions in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The driving unit 130 may move the lens 110 to the relative position in the second direction. The driving unit 130 may move the lens 110 in the XZ plane based on the relative position. The driving unit 130 may move the lens 110 in the first direction based on a first detection signal S1 (described later) or a second detection signal S2 (described later).

[0037] The relative positions in the first direction between the magnet 120 and the lens 110 and the first sensor 10 and the second sensor 12 may change. Fig. 1A shows an example in which the distance d in the first direction between the magnet 120 and the lens 110 and the first sensor 10 and the second sensor 12 is distance d1.

[0038] Fig. 1B is an example of a case where the distance d has changed from the distance d1 in the optical device 200 of Fig. 1A. In the example of Fig. 2, the distance d in the first direction is a distance d2. The distance d2 is greater than the distance d1. The relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 in at least one of the first direction and the second direction may change when the magnet moves while the first sensor 10 and the second sensor 12 are fixed, or may change when the first sensor 10 and the second sensor 12 move while the magnet is fixed.

[0039] Fig. 2 is a view of the optical device 200 of Fig. 1A as viewed from the X-axis direction. In this example, the image sensor 14 is provided in a recess 150. In Fig. 2, the driving unit 130 shown in Fig. 1A is omitted. Light projected from the lens 110 is incident on the image sensor 14. Fig. 2 shows an example in which the distance d is distance d1, but the distance d can vary between distance d1 and distance d2 (see Fig. 1B).

[0040] When the relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 in at least one of the first direction and the second direction change due to the movement of the first sensor 10 and the second sensor 12 while the magnet is fixed, the image sensor 14 may generate information on the feature amount related to the relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 in at least one of the first direction and the second direction by performing image processing on the light projected from the lens 110. In the example of FIG. 2, the image sensor 14 generates an image of the object projected on the lens 110, and generates a feature amount related to the relative position based on the generated image. The feature amount related to the relative position is, for example, the brightness of light that changes depending on the relative position.

[0041] The position detection device 100 may detect the relative positions between the first sensor 10 and the second sensor 12 and the magnet 120 in at least one of the first direction and the second direction based on the information of the feature amount generated by the image sensor 14, and may correct the relative positions so that the feature amount is constant. When the position detection device 100 corrects the relative positions, the relative positions between the image sensor 14 and the position detection device 100 in the first direction and the second direction do not need to change. Even if the image sensor 14 is disposed outside the position detection device 100, the relative positions between the image sensor 14 and the position detection device 100 in the first direction and the second direction do not need to change.

[0042] Fig. 3 is a diagram showing an example of a position detection device 100 according to an embodiment of the present invention. In Fig. 3, the lens 110 in Figs. 1A, 1B, and 2 is omitted. The position detection device 100 includes a first sensor 10 and a second sensor 12, an adjustment unit 20, and a calculation unit 30. The position detection device 100 may include an amplifier 40 and a position acquisition unit 22.

[0043] As described above, the first sensor 10 and the second sensor 12 are provided to face the magnet 120 in the first direction. In the position detection device 100, the first sensor 10 and the second sensor 12 may be disposed closer to the magnet 120 in the first direction than the amplifier 40, the calculation unit 30, the adjustment unit 20, and the AD converter 50 (described later).

[0044] A part or the whole of the position detection device 100 may be realized by a computer. The calculation unit 30 may be a CPU (Central Processing Unit) of the computer. The calculation unit 30 and the adjustment unit 20 may be the CPU of the computer. When the position detection device 100 is realized by a computer, a position detection program for causing the computer to function as the position detection device 100 may be installed in the computer, and a position detection program for causing the computer to execute a position detection method described later may be installed in the computer.

[0045] In this example, the amplifier 40 includes a first amplifier 42 and a second amplifier 44. The specifications of the first amplifier 42 and the second amplifier 44 may be the same. The specifications being the same means that the amplification factor, voltage gain, etc. of the first amplifier 42 and the second amplifier 44 are the same.

[0046] The first sensor 10 detects a change in magnetic flux based on a change in the relative position between the first sensor 10 and the magnet 120 in the second direction. The detection signal detected by the first sensor 10 is referred to as a first detection signal S1. The second sensor 12 detects a change in magnetic flux based on a change in the relative position between the second sensor 12 and the magnet 120 in the second direction. The detection signal detected by the second sensor 12 is referred to as a second detection signal S2.

[0047] The amplifier 40 amplifies the first detection signal S1 and the second detection signal S2. In this example, the first amplifier 42 amplifies the first detection signal S1 and the second amplifier 44 amplifies the second detection signal S2. The amplification factor by which the first amplifier 42 amplifies the first detection signal S1 and the amplification factor by which the second amplifier 44 amplifies the second detection signal S2 may be the same or different. The amplified first detection signal S1 is referred to as a first detection signal S1'. The amplified second detection signal S2 is referred to as a second detection signal S2'.

[0048] The sum of the first detection signal S1 and the second detection signal S2 is the sum signal Sm. The difference between the first detection signal S1 and the second detection signal S2 is the difference signal Sd. The calculation unit 30 calculates the sum signal Sm and the difference signal Sd. In this example, the sum signal Sm is the sum of the first detection signal S1' and the second detection signal S2', and the difference signal Sd is the difference between the first detection signal S1' and the second detection signal S2'. The calculation unit 30 calculates a ratio signal Sr (=Sm / Sd) between the sum signal Sm and the difference signal Sd, or a ratio signal Sr' (=Sd / Sm) between the difference signal Sd and the sum signal Sm. The calculation unit 30 may output a signal obtained by multiplying the ratio signal Sr or the ratio signal Sr' by a predetermined coefficient α.

[0049] The relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 may change in the XZ plane. In the position detection device 100, the calculation unit 30 calculates the ratio signal Sr or the ratio signal Sr'. Compared to the sum signal Sm or the difference signal Sd, the ratio signal Sr and the ratio signal Sr' are less susceptible to the effect of the change in the relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 in the XZ plane. Therefore, in the position detection device, even if the relative positions of the first sensor 10 and the second sensor 12 and the magnet 120 in the XZ plane change, the calculation unit 30 can output a signal (the ratio signal Sr or the ratio signal Sr') in which the effect of the change in the relative positions is suppressed.

[0050] Fig. 4 is a diagram showing an example of the first detection signal S1 when the distance d is distance d1. Fig. 5 is a diagram showing an example of the first detection signal S1 when the distance d is distance d2 (>distance d1). Figs. 4 and 5 show examples of the measurement results when the first detection signal S1 is measured from time ts to time te while maintaining the distance d at distance d1 and distance d2, respectively.

[0051] When the first sensor 10 measures the first detection signal S1, the output of the first sensor 10 may include the first detection signal S1 and noise of the first sensor 10. The larger the distance d, the smaller the first detection signal S1 is likely to be. The noise of the first sensor 10 is less dependent on the distance d. For this reason, as shown in Figs. 4 and 5, the ratio of the noise of the first sensor 10 to the first detection signal S1 is likely to be larger as the distance d is larger. Although the above has been described using an example of the first detection signal S1, the same applies to the second detection signal S2.

[0052] The adjustment unit 20 (see FIG. 3) adjusts the amplification factor of the first detection signal S1 and the amplification factor of the second detection signal S2 in accordance with the movement of the first sensor 10 and the second sensor 12, or the magnet 120. The movement of the first sensor 10 and the second sensor 12, or the magnet 120 may refer to movement in a first direction.

[0053] In the optical device 200 (see FIGS. 1A, 1B, and 2), the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the first direction may change. The position acquisition unit 22 (see FIG. 3) may acquire the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the first direction. The position acquisition unit 22 may acquire the positions of the first sensor 10 and the second sensor 12 in the first direction, and may acquire the position of the magnet 120 in the first direction. The position acquisition unit 22 may acquire the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the first direction based on the positions of the first sensor 10 and the second sensor 12 in the first direction and the position of the magnet 120 in the first direction. The position acquisition unit 22 may acquire a distance d in the first direction (see FIGS. 1A, 1B, and 2).

[0054] 6 and 7 are examples of measurement results of the input voltage Vin to the amplifier 40, the noise N of the first sensor 10 and the second sensor 12, and the signal Sm amplified by the amplifier 40. The input voltage Vin corresponds to the voltages of the first detection signal S1 and the second detection signal S2. The signal Sm corresponds to the first detection signal S1' and the second detection signal S2'. FIG. 6 shows an example in which the amplification factor A of the amplifier 40 is fixed. FIG. 7 shows an example in which the amplification factor A of the amplifier 40 is adjusted as described below.

[0055] The adjustment unit 20 (see FIG. 3) may adjust the amplification factors of the first detection signal S1 and the second detection signal S2 based on the relative positions in the first direction between the first sensor 10, the second sensor 12, and the magnet 120. The relative positions may be acquired by the position acquisition unit 22 (see FIG. 3). In the example of FIG. 3, the adjustment unit 20 adjusts the amplification factor of the amplifier 40 to adjust the amplification factor of the first detection signal S1 and the amplification factor of the second detection signal S2.

[0056] The adjustment unit 20 (see FIG. 3) may increase the amplification factor as the distance d increases. FIG. 7 shows an example in which the adjustment unit 20 increases the amplification factor at the distance d2 (>distance d1) more than the amplification factor at the distance d1. The input voltage Vin at the distance d2 is smaller than the input voltage Vin at the distance d1. Therefore, in the example of FIG. 6, the signal Sm at the distance d1 is smaller than the signal Sm at the distance d2. Therefore, the SN ratio at the distance d2 is worse than the SN ratio at the distance d1. In the example of FIG. 7, the amplification factor A at the distance d2 is larger than the amplification factor A at the distance d1. Therefore, the signal Sm at the distance d2 is larger than the signal Sm at the distance d1. Therefore, in the example of FIG. 7, as shown by the thick line frame, the SN ratio at the distance d2 is improved more than the SN ratio at the distance d1.

[0057] The adjustment unit 20 (see FIG. 3) may reduce the amplification factor as the distance d becomes smaller. As the distance d becomes smaller, the first detection signal S1 and the second detection signal S2 tend to become larger. Therefore, the first detection signal S1' obtained by amplifying the first detection signal S1 and the second detection signal S2' obtained by amplifying the second detection signal S2 tend to become larger. Therefore, the magnitudes of the first detection signal S1' and the second detection signal S2' may exceed the allowable range of the magnitude of the input signal in the calculation unit 30. By the adjustment unit 20 reducing the amplification factor as the distance d becomes smaller, the position detection device 100 can easily prevent the magnitudes of the first detection signal S1' and the second detection signal S2' from exceeding the allowable range of the magnitude of the input signal in the calculation unit 30.

[0058] When the distance d changes, the adjustment unit 20 (see FIG. 3) may adjust the amplification factor so that the magnitudes of the first detection signal S1' and the second detection signal S2' are the same regardless of the change in the distance d. The adjustment unit 20 may adjust the amplification factor when the distance d is distance d2 (>distance d1) to be larger than the amplification factor when the distance d is distance d1.

[0059] 8 is a diagram showing another example of a position detection device 100 according to an embodiment of the present invention. In this example, the position detection device 100 does not include a position acquisition unit 22. In this example, the adjustment unit 20 adjusts the amplification factor of the amplifier 40 based on a difference signal Sd between the first detection signal S1' and the second detection signal S2'. This example differs from the position detection device 100 in FIG. 3 in these respects. In this example, the direction from the N pole to the S pole of the magnet 120 is the second direction.

[0060] FIG. 9 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d1 (FIG. 1A) in the example of FIG. 8. FIG. 10 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d2 (>distance d1) (FIG. 1B) in the example of FIG. 8. The signals include the first detection signal S1', the second detection signal S2', the sum signal Sm, the difference signal Sd, and the ratio signal Sr. The relative position in the second direction is the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The scales on the axes of the output values ​​of each signal in FIG. 9 and FIG. 10 are the same.

[0061] As is clear from Fig. 9 and Fig. 10, in the example of Fig. 8, the difference signal Sd is less dependent on the relative position in the second direction. The difference signal Sd changes according to the distance d. Fig. 10 shows the difference signal Sd in Fig. 9. The greater the distance d, the smaller the difference signal Sd. Therefore, the adjustment unit 20 can calculate the distance d based on the difference signal Sd. Therefore, the adjustment unit 20 can adjust the amplification factor of the amplifier 40 based on the difference signal Sd.

[0062] When the adjustment section 20 adjusts the amplification factor of the amplifier 40 based on the difference signal Sd between the first detection signal S1' and the second detection signal S2', the calculation section 30 may calculate a ratio signal Sr between the sum signal Sm and the difference signal Sd.

[0063] In the example of FIG. 8, the adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on a difference signal Sd between the first detection signal S1' and the second detection signal S2' and a current amplification factor in the adjustment unit 20. The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the magnitude relationship between the difference signal Sd and the current amplification factor. The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the magnitude relationship between the difference signal Sd and a threshold value of the amplification factor. The threshold value of the amplification factor may be determined in advance. The threshold value of the amplification factor may be stored in the adjustment unit 20.

[0064] A plurality of thresholds of the amplification factor may be predefined. For example, in a case where a threshold th1, a threshold th2 (>threshold th1), and a threshold th3 (>threshold th2) are predefined as three thresholds th, and the adjustment unit 20 adjusts the amplification factor according to the distance d, if the current amplification factor adjusted according to the distance d exceeds the threshold th1, the adjustment unit 20 may adjust the amplification factor of the amplifier 40 to the threshold th2. Similarly, if the current amplification factor of the amplifier 40 exceeds the threshold th2, the adjustment unit 20 may adjust the amplification factor of the amplifier 40 to the threshold th3.

[0065] 9 and 10, in the example of Fig. 8, the ratio signal Sr (=Sm / Sd) is unlikely to change according to the distance d. Therefore, in the example of Fig. 8, the position detection device 100 detects the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the second direction based on the ratio signal Sr.

[0066] The input signal to the first sensor 10 is In1, and the input signal to the second sensor 12 is In2. The amplification factor of the first amplifier 42 and the second amplifier 44 is A. The noise after the first amplifier 42 in the signal path from the first sensor 10 and the second sensor 12 to the amplifier 40, the calculation unit 30, the adjustment unit 20, and the amplifier 40 is N1, and the noise after the second amplifier 44 is N2. The position signal indicating the relative position of the first sensor 10 and the second sensor 12 to the magnet 120 in the second direction is Sp. The position signal Sp is expressed by the following equation 1.

number

[0067] As is clear from formula 1, the influence of noise N1 and noise N2 on position signal Sp decreases as the amplification factor A increases, which makes it easier for the position detection device 100 to accurately detect the relative position in the second direction.

[0068] 11 is a diagram showing another example of a position detection device 100 according to an embodiment of the present invention. In this example, the direction from the north pole to the south pole of the magnet 120 is the first direction. In this example, the adjustment unit 20 adjusts the amplification factor of the amplifier 40 based on the sum signal Sm of the first detection signal S1' and the second detection signal S2'. This example differs from the position detection device 100 in FIG. 8 in these respects.

[0069] FIG. 12 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d1 (FIG. 1A) in the example of FIG. 11. FIG. 13 is a diagram showing an example of the relationship between each signal and the relative position in the second direction when the distance d is distance d2 (>distance d1) (FIG. 1B) in the example of FIG. 11. The signals include a first detection signal S1', a second detection signal S2', a sum signal Sm, a difference signal Sd, and a ratio signal Sr'. The relative position in the second direction is the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The scales on the axis of the signal output in FIG. 12 and FIG. 13 are the same.

[0070] As is clear from Fig. 12 and Fig. 13, in the example of Fig. 11, the sum signal Sm is less dependent on the relative position in the second direction. The sum signal Sm changes according to the distance d. Fig. 13 shows the sum signal Sm in Fig. 12. The larger the distance d, the smaller the sum signal Sm. Therefore, the adjustment unit 20 can calculate the distance d based on the sum signal Sm. Therefore, the adjustment unit 20 can adjust the amplification factor of the amplifier 40 based on the sum signal Sm.

[0071] When the adjustment section 20 adjusts the amplification factor of the amplifier 40 based on the sum signal Sm of the first detection signal S1' and the second detection signal S2', the calculation section 30 may calculate a ratio signal Sr' between the difference signal Sd and the sum signal Sm.

[0072] 11, the adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on a sum signal Sm of the first detection signal S1' and the second detection signal S2' and the current amplification factor of the adjustment unit 20. The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the magnitude relationship between the sum signal Sm and a threshold value of the amplification factor. As in the example of FIG. 8, multiple threshold values ​​of the amplification factor may be determined in advance.

[0073] 12 and 13, in the example of Fig. 11, the ratio signal Sr' (=Sd / Sm) is unlikely to change according to the distance d. Therefore, in the example of Fig. 11, the position detection device 100 detects the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the second direction based on the ratio signal Sr'.

[0074] 14 is a diagram showing another example of the position detection device 100 according to an embodiment of the present invention. The position detection device 100 of this example includes a third sensor 24. The third sensor 24 detects the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the first direction. The third sensor 24 of this example is an example of the position acquisition unit 22 in the position detection device 100 of FIG.

[0075] The third sensor 24 may be a magnetic sensor. When the third sensor 24 is a magnetic sensor, the third sensor 24 detects the magnetic flux caused by the magnet 120. The third sensor 24 may be fixed in the first direction. The third sensor 24 may detect a change in the magnetic flux caused by the magnet 120 moving in the first direction. The third sensor 24 may detect the relative positions of the first sensor 10 and the second sensor 12, and the magnet 120 in the first direction by detecting the change in the magnetic flux.

[0076] Fig. 15 is a diagram showing another example of a position detection device 100 according to an embodiment of the present invention. The position detection device 100 of this example differs from the position detection device 100 of Fig. 3 in that it does not include the position acquisition unit 22 in the position detection device 100 of Fig. 3, but includes a position acquisition unit 26 and a change rate calculation unit 28.

[0077] The position acquisition unit 26 acquires the relative positions in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The position acquisition unit 26 may acquire the positions in the second direction of the first sensor 10 and the second sensor 12, and may acquire the position of the magnet 120 in the second direction. The position acquisition unit 26 may acquire the relative positions in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120 based on the positions in the second direction of the first sensor 10 and the second sensor 12 and the position of the magnet 120 in the second direction.

[0078] The change rate calculation unit 28 calculates the change rate of the first detection signal S1 or the second detection signal S2 with respect to the change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. In this example, the change rate calculation unit 28 calculates the change rate of the second detection signal S2 with respect to the change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. The change rate of the first detection signal S1 or the second detection signal S2 with respect to the change in the relative position in the second direction in FIG. 9 is different from the change rate in FIG. 10. The change rate when the distance d in the first direction is distance d1 (in the case of FIG. 9) is larger than the change rate when the distance d is distance d2 (in the case of FIG. 10). Therefore, the change rate calculation unit 28 can detect the relative position in the first direction between the first sensor 10 and the second sensor 12 and the magnet 120 by calculating the change rate.

[0079] The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the rate of change of the first detection signal S1 or the second detection signal S2 with respect to the change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. As described above, the change rate calculation unit 28 can detect the relative position in the first direction between the first sensor 10 and the second sensor 12 and the magnet 120 by calculating the change rate of the first detection signal S1 or the second detection signal S2 with respect to the change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. Therefore, the adjustment unit 20 can adjust the amplification factor of the amplifier 40 based on the change rate of the first detection signal S1 or the second detection signal S2 with respect to the change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120.

[0080] FIG. 16 is a diagram showing an example of the relationship between the first detection signal S1' and the second detection signal S2' and the relative position in the second direction when the distance d is distance d1 (FIG. 1A) in the example of FIG. 8. FIG. 17 is a diagram showing an example of the relationship between the first detection signal S1' and the second detection signal S2' and the relative position in the second direction when the distance d is distance d2 (>distance d1) (FIG. 1B) in the example of FIG. 8. The relative position is the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120. FIG. 16 and FIG. 17 are diagrams in which the sum signal Sm, the difference signal Sd, and the ratio signal Sr in FIG. 9 and FIG. 10 are deleted, respectively.

[0081] A target position of the magnet 120 in the second direction relative to the first sensor 10 and the second sensor 12 is set as a target position Pa. The target position Pa may be determined in advance. In the examples of Fig. 16 and Fig. 17, the target position Pa of the magnet 120 is the midpoint between the first sensor 10 and the second sensor 12 in the second direction.

[0082] In the second direction, the current position of the magnet 120 relative to the first sensor 10 and the second sensor 12 is assumed to be a current position Pb. The change in the relative position of the magnet 120 in the second direction between the first sensor 10 and the second sensor 12 and the first sensor 10 may be the difference between the target position Pa and the current position Pb.

[0083] The signal Sa may be the signal value of the first detection signal S1' or the second detection signal S2' when the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120 is the target position Pa. The signal Sb may be the signal value of the first detection signal S1' or the second detection signal S2' when the relative position is the current position Pb. In the examples of Fig. 16 and Fig. 17, the signals Sa and Sb are the signal value of the first detection signal S1'.

[0084] The change rate calculation unit 28 may calculate a ratio of the difference between the signal Sb and the signal Sa to the difference between the target position Pa and the current position Pb. As is clear from Figs. 16 and 17, this ratio depends on the distance d. Therefore, the change rate calculation unit 28 can detect the relative positions in the first direction between the first sensor 10 and the second sensor 12, and the magnet 120, based on the calculated ratio. The adjustment unit 20 may adjust the amplification factor of the amplifier 40, based on the relative positions in the first direction detected by the change rate calculation unit 28.

[0085] 18 and 19 are diagrams showing another example of the position detection device 100 according to an embodiment of the present invention. In the example of Fig. 18, the direction from the N pole to the S pole of the magnet 120 is the second direction. In the example of Fig. 19, the direction from the N pole to the S pole of the magnet 120 is the first direction.

[0086] The adjustment unit 20 may adjust the amplification factor of the first detection signal S1 and the amplification factor of the second detection signal S2 by adjusting the amplification factor of the first sensor 10 and the amplification factor of the second sensor 12. When the first sensor 10 and the second sensor 12 are Hall elements, the adjustment unit 20 may adjust the amplification factor of the electromagnetic conversion unit of the Hall elements. The first detection signal S1 and the second detection signal S2 amplified by the amplification factor adjusted by the adjustment unit 20 are respectively set as the first detection signal S11 and the second detection signal S21. In this example, the first sensor 10 outputs the first detection signal S11, and the second sensor 12 outputs the second detection signal S21.

[0087] In the example of Fig. 18, the adjustment unit 20 adjusts the amplification factor of the first sensor 10 and the amplification factor of the second sensor 12 based on the difference signal Sd between the first detection signal S1' and the second detection signal S2'. As described in the example of Fig. 8, when the direction from the north pole to the south pole of the magnet 120 is the second direction, the difference signal Sd changes according to the distance d. Therefore, the adjustment unit 20 can adjust the amplification factor of the first sensor 10 and the amplification factor of the second sensor 12 based on the difference signal Sd.

[0088] 19, the adjustment unit 20 adjusts the amplification factor of the first sensor 10 and the amplification factor of the second sensor 12 based on the sum signal Sm of the first detection signal S1' and the second detection signal S2'. As described in the example of FIG. 11, when the direction from the north pole to the south pole of the magnet 120 is the first direction, the sum signal Sm changes according to the distance d. Therefore, the adjustment unit 20 can adjust the amplification factor of the first sensor 10 and the amplification factor of the second sensor 12 based on the sum signal Sd.

[0089] Fig. 20 is a diagram showing another example of the position detection device 100 according to an embodiment of the present invention. In this example, the calculation unit 30 calculates a difference signal Sd' between the first detection signal S1 and the second detection signal S2, in addition to the difference signal Sd (the difference between the first detection signal S1' and the second detection signal S2') in the example of Fig. 8. The first detection signal S1 and the second detection signal S2 are the first detection signal S1 and the second detection signal S2, respectively, before being amplified by the amplifier 40. The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the difference signal Sd'.

[0090] Fig. 21 is a diagram showing another example of the position detection device 100 according to an embodiment of the present invention. In this example, the calculation unit 30 calculates a sum signal Sm' of the first detection signal S1 and the second detection signal S2, in addition to the sum signal Sd (the sum of the first detection signal S1' and the second detection signal S2') in the example of Fig. 11. The adjustment unit 20 may adjust the amplification factor of the amplifier 40 based on the sum signal Sm'.

[0091] 22 and 23 are diagrams showing another example of a position detection device 100 according to an embodiment of the present invention. The position detection device 100 in FIG. 22 differs from the position detection device 100 in FIG. 8 in that it further includes an AD converter 50. The position detection device 100 in FIG. 23 differs from the position detection device 100 in FIG. 11 in that it further includes an AD converter 50. The first detection signal S1 and the second detection signal S2 are analog signals. The AD converter 50 converts the first detection signal S1 into a first digital signal and converts the second detection signal S2 into a second digital signal. In this example, the AD converter 50 converts the first detection signal S1' into a first digital signal S1'', and converts the second detection signal S2' into a second digital signal S2''.

[0092] 22 and 23, the AD converter 50 includes a first AD converter 52, a second AD converter 54, and a reference voltage Vref supplier 56. The first AD converter 52 converts the first detection signal S1 into a first digital signal. The second AD converter 54 converts the second detection signal S2 into a second digital signal. The reference voltage Vref supplier 56 supplies a reference voltage Vref for AD conversion.

[0093] The specifications of the first AD converter 52 and the second AD converter 54 may be the same. The specifications being the same means that the conversion time, conversion delay, etc. of the first AD converter 52 and the second AD converter 54 are the same.

[0094] In the example of FIG. 22, the adjustment section 20 adjusts the amplification factor of the AD converter 50 based on a difference signal Sd between the first detection signal S1'' and the second detection signal S2''. In the example of FIG. 23, the adjustment section 20 adjusts the amplification factor of the first AD converter 52 and the amplification factor of the second AD converter 54 based on a sum signal Sm of the first detection signal S1'' and the second detection signal S2''. In the examples of FIG. 22 and FIG. 23, the adjustment section 20 may adjust the amplification factor of the first detection signal S1 and the amplification factor of the second detection signal S2 by adjusting the amplification factor of the AD converter 50. In the examples of FIG. 22 and FIG. 23, the adjustment section 20 adjusts the amplification factor of the first detection signal S1' and the amplification factor of the second detection signal S2' by adjusting the amplification factor of the first AD converter 52 and the amplification factor of the second AD converter 54.

[0095] Fig. 24 is a diagram showing another example of the position detection device 100 according to an embodiment of the present invention. In this example, an adjustment unit 20 adjusts the amplification factor of an amplifier 40. This example differs from the position detection device 100 in Fig. 22 in this respect.

[0096] The AD converter 50 may convert the first detection signal S1', which has a signal level within a predetermined first range, into a first digital signal S1'', and may convert the second detection signal S2', which has a signal level within a predetermined second range, into a second digital signal S2''. The predetermined first and second ranges may be the AD conversion ranges specified in the first and second AD converters 52 and 54, respectively. When the specifications of the first AD converter 52 and the second AD converter 54 are the same, the first and second ranges may be the same.

[0097] FIG. 25 is a diagram showing a schematic diagram of the first range of the first AD converter 52. The lower limit and upper limit of the first range are defined as lower limit Rmin and upper limit Rmax, respectively. The center of the first range is defined as center Rc. When the magnitude of the input signal to the first AD converter 52 (the first detection signal S1' in the example of FIG. 24) is within the first range, the first AD converter 52 can convert the input signal into a digital signal. The above also applies to the second range.

[0098] FIG. 25 shows the setting range in the first range. The setting range is included in the first range. The lower limit and upper limit of the setting range are the lower limit Dmin and the upper limit Dmax, respectively. The lower limit Dmin may be larger than the lower limit Rmin. The upper limit Dmax may be smaller than the upper limit Rmax. The center of the setting range may be the same as the center R, or may be different. The above also applies to the second range.

[0099] The set range may be a range of a predetermined ratio to the first range. The ratio may be 60%, 70%, or 80%. An input signal near the lower limit Rmin or near the upper limit Rmax may not be AD converted according to the specifications of the first AD converter 52. For this reason, it is preferable that the first AD converter 52 does not AD convert an input signal near the lower limit Rmin or near the upper limit Rmax. The above also applies to the second AD converter 54.

[0100] The adjustment section 20 may adjust the amplification factor of the first detection signal S1 based on the magnitude of the first range, and may adjust the amplification factor of the second detection signal S2 based on the magnitude of the second range. In this example, the adjustment section 20 adjusts the amplification factor of the amplifier 40 based on the magnitude of the first range or the second range. The adjustment section 20 may adjust the amplification factor of the first detection signal S1 so that the magnitude of the first detection signal S1' falls within the set range of FIG. 25, and may adjust the amplification factor of the second detection signal S2 so that the magnitude of the second detection signal S2' falls within the set range of FIG. 25. This allows the first detection signal S1' and the second detection signal S2' amplified by the amplifier 40 to be reliably AD converted by the AD converter 50.

[0101] 26 is a diagram showing another example of the position detection device 100 according to an embodiment of the present invention. The adjustment unit 20 may adjust the amplification factor of the first detection signal S1 and the amplification factor of the second detection signal S2 by adjusting the reference voltage Vref of the AD converter 50. In this example, the adjustment unit 20 adjusts the amplification factor of the first detection signal S1'' and the amplification factor of the second detection signal S2'' by adjusting the reference voltage Vref of the AD converter 50.

[0102] 27 is a flowchart showing an example of a position detection method according to an embodiment of the present invention. The position detection method includes an adjustment step S100 and a calculation step S104. The position detection method may include a detection step S90 and an amplification step S102. The position detection method according to an embodiment of the present invention will be described using the position detection device 100 shown in FIG. 3 as an example.

[0103] The detection step S90 is a step in which the first sensor 10 and the second sensor 12, which are arranged to face the magnet 120 placed at a reference position in a first direction, detect a change in magnetic flux based on a change in the relative position in the second direction between the first sensor 10 and the second sensor 12 and the magnet 120.

[0104] The adjustment step S100 is a step in which the adjustment unit 20 adjusts the amplification factor of the first detection signal S1 detected by the first sensor 10 in the detection step S90 and the amplification factor of the second detection signal S2 detected by the second sensor 12 in accordance with the movement of the first sensor 10 and the second sensor 12, or the magnet 120.

[0105] The amplifying step S102 is a step in which the amplifier 40 amplifies the first detection signal S1 and the second detection signal S2 with the amplification factor adjusted in the adjusting step S100.

[0106] The calculation step S104 is a step in which the calculation unit 30 calculates the ratio (ratio signal Sr(=Sm / Sd)) of the sum (sum signal Sm) of the first detection signal S1 (first detection signal S1') and the second detection signal S2 (second detection signal S2') amplified in the amplification step S102 to the difference (difference signal Sd) between the first detection signal S1 (first detection signal S1') and the second detection signal S2 (second detection signal S2'), or the ratio (ratio signal Sr(=Sd / Sm)) of the difference signal Sd and the sum signal Sm.

[0107] Fig. 28 is a flowchart showing another example of a position detection method according to an embodiment of the present invention. The position detection method of this example differs from the position detection method of Fig. 27 in that it further includes an amplification step S92. The position detection method of this example differs from the position detection method of Fig. 27 in that it includes a calculation step S96 instead of the calculation step S106. The position detection method of this example will be described using the position detection device 100 shown in Figs. 8 and 11 as an example. In the position detection method of this example, the detection step S90 and the amplification step S102 are the same as the position detection method of Fig. 27, so their description will be omitted.

[0108] The amplifying step S92 is a step in which the amplifier 40 amplifies the first detection signal S1 detected by the first sensor 10 and the second detection signal S2 detected by the second sensor 12 in the detecting step S90.

[0109] In the case of the position detection method in the position detection device 100 of Fig. 8, the calculation step S96 is a step in which the calculation unit 30 calculates a ratio (ratio signal Sr (=Sm / Sd)) between the sum (sum signal Sm) of the first detection signal S1 (first detection signal S1') and the second detection signal S2 (second detection signal S2') amplified in the amplification step S92 and the difference (difference signal Sd) between the first detection signal S1 (first detection signal S1') and the second detection signal S2 (second detection signal S2'). In the case of the position detection method in the position detection device 100 of Fig. 11, the calculation step S96 is a step in which the calculation unit 30 calculates the ratio signal Sr' (=Sd / Sm).

[0110] The adjustment step S100 is a step in which the adjustment unit 20 adjusts the gain of the amplifier 40 based on the difference signal Sd calculated in the calculation step S96. The amplification step S102 is a step in which the amplifier 40 amplifies the first detection signal S1 and the second detection signal S2 with the gain adjusted in the adjustment step S100.

[0111] Fig. 29 is a flowchart showing another example of a position detection method according to an embodiment of the present invention. The position detection method of this example differs from the position detection method of Fig. 28 in that it further includes an AD conversion step S94. The position detection method of this example differs from the position detection method of Fig. 28 in that it includes an AD conversion step S106 instead of the amplification step S102. The position detection method of this example will be described using the position detection device 100 shown in Figs. 22 and 23 as an example. In the position detection method of this example, the detection step S90 and the amplification step S92 are the same as the position detection method of Fig. 28, so their description will be omitted.

[0112] The AD conversion step S94 is a step of converting the first detection signal S1 (first detection signal S1') amplified in the amplification step S92 into a first digital signal S1'', and converting the first detection signal S2 (first detection signal S2') into a second digital signal S2''.

[0113] In the case of the position detection method in the position detection device 100 of FIG. 22, the calculation step S96 is a step in which the calculation unit 30 calculates the ratio (ratio signal Sr (=Sm / Sd)) of the sum (sum signal Sm) of the first detection signal S1 (first digital signal S1'') and the second detection signal S2 (second digital signal S2'') converted in the AD conversion step S94 to the difference (difference signal Sd) between the first detection signal S1 (first digital signal S1'') and the second detection signal S2 (second digital signal S2''). In the case of the position detection method in the position detection device 100 of FIG. 23, the calculation step S96 is a step in which the calculation unit 30 calculates the ratio signal Sr (=Sd / Sm).

[0114] The adjustment step S100 is a step in which the adjustment section 20 adjusts the amplification factor of the AD converter 50 based on the difference signal Sd calculated in the calculation step S96. The AD conversion step S106 is a step in which the AD converter 50 converts the first detection signal S1 (first detection signal S1') into a first digital signal S1" and converts the first detection signal S2 (first detection signal S2') into a second digital signal S2" with the amplification factor adjusted in the adjustment step S100.

[0115] FIG. 30 is a diagram showing an example of a computer 2200 in which the position detection device 100 according to an embodiment of the present invention may be embodied in whole or in part. A program installed in the computer 2200 can cause the computer 2200 to function as an operation associated with the position detection device 100 according to an embodiment of the present invention, or one or more sections of the position detection device 100, or can cause the computer 2200 to execute the operation or one or more sections, or can cause the computer 2200 to execute each step (see FIGS. 27 to 29) associated with the position detection method of the present invention. The program can be executed by the CPU 2212 to cause the computer 2200 to execute specific operations associated with some or all of the blocks in the flowcharts (FIGS. 27 to 29) and block diagrams (FIGS. 3, 8, 11, 14, 15, 18 to 24, and 26) described in this specification.

[0116] A computer 2200 according to an embodiment of the present invention includes a CPU 2212, a RAM 2214, a graphic controller 2216, and a display device 2218. The CPU 2212, the RAM 2214, the graphic controller 2216, and the display device 2218 are connected to each other by a host controller 2210. The computer 2200 further includes input / output units such as a communication interface 2222, a hard disk drive 2224, a DVD-ROM drive 2226, and an IC card drive. The communication interface 2222, the hard disk drive 2224, the DVD-ROM drive 2226, and the IC card drive are connected to the host controller 2210 via an input / output controller 2220. The computer further includes legacy input / output units such as a ROM 2230 and a keyboard 2242. The ROM 2230, the keyboard 2242, and the like are connected to the input / output controller 2220 via an input / output chip 2240.

[0117] The CPU 2212 controls each unit by operating according to programs stored in the ROM 2230 and the RAM 2214. The graphic controller 2216 acquires image data generated by the CPU 2212 into a frame buffer or the like provided in the RAM 2214 or into the RAM 2214, thereby causing the image data to be displayed on the display device 2218.

[0118] The communication interface 2222 communicates with other electronic devices via a network. The hard disk drive 2224 stores programs and data used by the CPU 2212 in the computer 2200. The DVD-ROM drive 2226 reads programs or data from the DVD-ROM 2201 and provides the read programs or data to the hard disk drive 2224 via the RAM 2214. The IC card drive reads programs and data from an IC card or writes programs and data to an IC card.

[0119] The ROM 2230 stores a boot program or the like that is executed by the computer 2200 upon activation, or a program that depends on the hardware of the computer 2200. The input / output chip 2240 may connect various input / output units to the input / output controller 2220 via a parallel port, a serial port, a keyboard port, a mouse port, or the like.

[0120] The programs are provided by a computer-readable medium such as a DVD-ROM 2201 or an IC card. The programs are read from the computer-readable medium, installed in the hard disk drive 2224, the RAM 2214, or the ROM 2230, which are also examples of computer-readable media, and executed by the CPU 2212. Information processing described in these programs is read by the computer 2200, and brings about cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be constructed by implementing information manipulation or processing according to the use of the computer 2200.

[0121] For example, when communication is performed between the computer 2200 and an external device, the CPU 2212 may execute a communication program loaded in the RAM 2214 and instruct the communication interface 2222 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 2212, the communication interface 2222 reads transmission data stored in a transmission buffer processing area provided in the RAM 2214, the hard disk drive 2224, the DVD-ROM 2201, or a recording medium such as an IC card, and transmits the read transmission data to a network, or writes reception data received from the network to a reception buffer processing area or the like provided on the recording medium.

[0122] The CPU 2212 may cause all or a necessary portion of a file or database stored in an external recording medium such as the hard disk drive 2224, the DVD-ROM drive 2226 (DVD-ROM 2201), an IC card, etc. to be read into the RAM 2214. The CPU 2212 may perform various types of processing on the data on the RAM 2214. The CPU 2212 may then write back the processed data to the external recording medium.

[0123] Various types of information, such as various types of programs, data, tables, and databases, may be stored in the recording medium and processed. The CPU 2212 may execute various types of processing on the data read from the RAM 2214, including various types of operations, information processing, conditional decisions, conditional branches, unconditional branches, information searches or replacements, etc., specified by the instruction sequences of the programs described in this disclosure. The CPU 2212 may write back the results to the RAM 2214.

[0124] CPU2212 may search for information in a file, database, etc. in the recording medium. For example, when a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, CPU2212 may search for an entry that matches a condition in which the attribute value of the first attribute is specified from among the plurality of entries, read the attribute value of the second attribute stored in the entry, and obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition by reading the second attribute value.

[0125] The above-mentioned program or software module may be stored on the computer 2200 or in a computer-readable medium of the computer 2200. A recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer-readable medium. The program may be provided to the computer 2200 by the recording medium.

[0126] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0127] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0128] REFERENCE SIGNS LIST 10 first sensor, 12 second sensor, 14 image sensor, 20 adjustment section, 22 position acquisition section, 24 third sensor, 26 position acquisition section, 28 rate of change calculation section, 30 calculation section, 40 amplifier, 42 first amplifier, 44 second amplifier, 50 AD converter, 52 first AD converter, 54 second AD converter, 56 reference voltage Vref supplier, 100 position detection device, 110 lens, 120 magnet, 130 drive section, 140 lens support section, 150 recessed section, 160 Housing, 162···first member, 164···second member, 200···optical device, 2200···computer, 2201···DVD-ROM, 2210···host controller, 2212···CPU, 2214···RAM, 2216···graphic controller, 2218···display device, 2220···input / output controller, 2222···communication interface, 2224···hard disk drive, 2226···DVD-ROM drive, 2230···ROM, 2240···input / output chip, 2242···keyboard

Claims

1. a first sensor and a second sensor that are provided to face a magnet arranged at a reference position in a first direction and detect a magnetic flux generated by the magnet, the first sensor and the second sensor detecting a change in the magnetic flux based on a change in a relative position between the first sensor and the second sensor and the magnet in a second direction that intersects with the first direction; an adjustment unit that adjusts an amplification factor of a first detection signal detected by the first sensor and an amplification factor of a second detection signal detected by the second sensor in accordance with movement of the first sensor and the second sensor, or movement of the magnet; a calculation unit that calculates a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal, or a ratio between the difference and the sum; A position detection device comprising:

2. The position detection device according to claim 1 , wherein the adjustment unit adjusts the amplification factor based on relative positions of the first sensor, the second sensor, and the magnet in the first direction.

3. the difference is a difference between the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor, The adjustment unit adjusts the amplification factor based on the difference between the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor, The calculation unit calculates a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal. The position detection device according to claim 1 .

4. 4. The position detection device according to claim 3, wherein the adjustment unit adjusts the amplification factor based on the difference between the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor and a current amplification factor in the adjustment unit.

5. The position detection device according to claim 1 , wherein the adjustment unit adjusts the amplification factor based on the difference between the first detection signal and the second detection signal.

6. the sum is a sum of the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor, The adjustment unit adjusts the amplification factor based on the sum of the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor; The calculation unit calculates a ratio between a difference between the first detection signal and the second detection signal and a sum of the first detection signal and the second detection signal. The position detection device according to claim 1 .

7. 7. The position detection device according to claim 6, wherein the adjustment unit adjusts the amplification factor based on the sum of the first detection signal amplified by the amplification factor and the second detection signal amplified by the amplification factor and a current amplification factor in the adjustment unit.

8. The position detection device according to claim 1 , wherein the adjustment unit adjusts the amplification factor based on the sum of the first detection signal and the second detection signal.

9. The position detection device according to claim 2 , further comprising a third sensor that detects the relative position in the first direction.

10. The position detection device according to claim 1 , wherein the adjustment unit adjusts the amplification factor based on a rate of change of the first detection signal or the second detection signal with respect to a change in the relative position in the second direction.

11. 11. The position detection device of claim 10, wherein the change in the relative position in the second direction is a difference between a target position of the magnet relative to the first sensor and the second sensor in the second direction and a current position of the magnet relative to the first sensor and the second sensor in the second direction.

12. an AD converter that converts the first detection signal, the signal level of which is within a first predetermined range, into a first digital signal, and converts the second detection signal, the signal level of which is within a second predetermined range, into a second digital signal; The adjustment unit adjusts the amplification factor based on the magnitude of the first range or the second range. The position detection device according to claim 1 .

13. an amplifier that amplifies the first detection signal and that amplifies the second detection signal; the adjustment unit adjusts the amplification factor of the amplifier to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal. A position detection device according to any one of claims 1 to 12.

14. 13. The position detection device according to claim 1, wherein the adjustment unit adjusts the amplification factor of the first detection signal and the amplification factor of the second detection signal by adjusting the amplification factor of the first sensor and the amplification factor of the second sensor.

15. an AD converter that converts the first detection signal into a first digital signal and the second detection signal into a second digital signal; the adjustment unit adjusts an amplification factor of the AD converter to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal. A position detection device according to any one of claims 1 to 11.

16. an AD converter that converts the first detection signal into a first digital signal and the second detection signal into a second digital signal; the adjustment unit adjusts a reference voltage of the AD converter to adjust the amplification factor of the first detection signal and the amplification factor of the second detection signal. A position detection device according to any one of claims 1 to 11.

17. a lens disposed at the same relative position in the second direction as the relative position in the second direction relative to the first sensor and the second sensor; A drive unit that drives the lens; A position detection device according to any one of claims 1 to 12, Equipped with the first sensor and the second sensor detect the relative positions of the first sensor and the second sensor and the magnet in the second direction; the driving unit drives the lens based on the relative position in the second direction with respect to the magnet detected by the first sensor and the second sensor. optical equipment.

18. an adjustment step in which an adjustment unit adjusts an amplification factor of a first detection signal detected by the first sensor that detects a change in the magnetic flux based on a change in relative position between the first sensor and the second sensor and the magnet in a second direction that intersects the first direction, and an amplification factor of a second detection signal detected by the second sensor that detects the change in the magnetic flux, in accordance with a movement of the first sensor and the second sensor or the magnet; a calculation step in which a calculation unit calculates a ratio of a sum of the first detection signal and the second detection signal to a difference between the first detection signal and the second detection signal, or a ratio of the difference to the sum; A position detection method comprising:

19. On the computer, a first sensor and a second sensor are provided to face a magnet placed at a reference position in a first direction and detect a magnetic flux from the magnet, and an adjustment step is performed to adjust an amplification factor of a first detection signal detected by the first sensor that detects a change in the magnetic flux based on a change in relative position between the first sensor and the second sensor and the magnet in a second direction that intersects the first direction, and an amplification factor of a second detection signal detected by the second sensor that detects the change in the magnetic flux, in accordance with movement of the first sensor and the second sensor or the magnet; a calculation step of calculating a ratio between a sum of the first detection signal and the second detection signal and a difference between the first detection signal and the second detection signal, or a ratio between the difference and the sum; A location detection program that executes the following:

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