JP2005331401A - Position detector, mechanism for compensating unintended movement of hands, and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a microcomputer from being damaged in a position detector using a Hall element. <P>SOLUTION: In this position detector 10A, a voltage regulation circuit 37 and a limiter part 34 function so as to prevent the microcomputer 5 from being impressed with a high voltage, in a usual time. When the voltage regulation circuit 37 and the limiter part 34 are under a nonactive condition, an upstream circuit between a sensor power source 71 and a sensor part 2 is interrupted by a switching circuit 39. By this manner, the high voltage such as a voltage in the sensor power source 71 is precluded in any case from being impressed to the microcomputer 5 to prevent the microcomputer 5 from being damaged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a position detection device that detects the relative position of two objects, and a camera shake correction mechanism and an imaging device that use the position detection device.

  There are various types of position detection devices (such as a linear encoder) that detect the relative positions of two objects.

  If there is a demand for downsizing, cost reduction, power consumption, etc., among various methods, a magnetic position detection device using a permanent magnet (magnetic force generator) and a Hall element (magnetic sensor) It is preferable to use it. In the magnetic position detection device, the relative position of the permanent magnet with respect to the Hall element is obtained in the processing circuit that processes the output signal of the Hall element. Then, a position signal indicating the obtained relative position is output from the processing circuit to a microcomputer or the like as a calculation circuit that performs calculation based on the position.

  As prior art documents disclosing techniques related to the present invention, there are the following documents.

JP 2001-86783 A Japanese Patent Laid-Open No. 10-213451

  By the way, the Hall element and the magnet have a large characteristic change depending on the temperature, and the sensitivity of the magnetic position detecting device is easily affected by the environmental temperature. For this reason, it is conceivable to reduce the influence of the environmental temperature by adjusting the sensitivity by adjusting the input voltage of the Hall element. In order to perform such voltage adjustment with high accuracy, it is desirable to arrange a transistor as an adjustment circuit between the Hall element and the ground.

  This transistor adjusts the input voltage of the Hall element according to the base voltage in an activated state (a state in which a base current flows). On the other hand, in a non-activated state (a state in which the base current does not flow), this transistor cuts off between the power supply terminal on the negative side of the Hall element and the ground. For this reason, the power supply voltage of the Hall element may be applied to the microcomputer through the processing circuit as it is. In general, the power supply voltage of the Hall element is higher than the driving voltage of the microcomputer. For this reason, if the power supply voltage of the Hall element is directly applied to the microcomputer, the microcomputer may be destroyed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a position detection device that can prevent the destruction of an arithmetic circuit to which a position signal is output.

  In order to solve the above-mentioned problem, the invention of claim 1 is a position detection device, comprising: a sensor unit for detecting magnetism from a magnetic force generator; and the magnetic force generator based on an output value from the sensor unit. Position deriving means for deriving a relative position with respect to the sensor unit and outputting a position signal indicating the relative position to an arithmetic circuit; and a power supply terminal of the sensor unit with a voltage larger than a driving voltage of the arithmetic circuit A sensor power supply to be applied to the sensor unit; an adjustment circuit that adjusts an input value of the sensor unit in an active state; and a circuit that shuts off a downstream circuit between the other power supply terminal of the sensor unit and the ground in an inactive state And a switching circuit that shuts off an upstream circuit between the sensor power supply and the one power supply terminal of the sensor unit when the circuit is in an inactive state.

  According to a second aspect of the present invention, in the position detection device according to the first aspect, an instruction to shift the active state between the active state and the inactive state of the adjustment circuit and an instruction to switch connection / disconnection of the upstream circuit And an instruction means for instructing the transition of the adjustment circuit from the active state to the inactive state after a lapse of a predetermined time after an instruction to switch the upstream circuit from connection to disconnection. .

  According to a third aspect of the present invention, in the position detection device according to the first aspect, an instruction to shift the active state between the active state and the inactive state of the adjustment circuit and an instruction to switch connection / disconnection of the upstream circuit Instructing means for performing switching, and after the predetermined time has elapsed after the instruction to shift the adjustment circuit from the inactive state to the active state, the instruction means instructs to switch the upstream circuit from shut-off to connection. .

  According to a fourth aspect of the present invention, in the position detection device according to any one of the first to third aspects, the sensor unit is configured by a pair of magnetic sensor pairs arranged to be separated from each other, and the position derivation is performed. Means derives the relative position based on each output value from the set of magnetic sensor pairs, and the adjustment circuit adjusts each voltage applied to the set of magnetic sensor pairs in an active state; The sum of the magnitudes of the output values from the pair of magnetic sensor pairs is a constant value.

  According to a fifth aspect of the present invention, in the position detection device according to the fourth aspect, the combination of the one set of magnetic sensor pair, the one position derivation means, and the one adjustment circuit is a detection unit. Then, the plurality of detection units are provided, and the arrangement of the pair of magnetic sensors included in each of the plurality of detection units is relatively fixed between the plurality of detection units.

  According to a sixth aspect of the present invention, in the position detection device according to the fifth aspect, one of the switching circuits is shared among the plurality of detection units.

  According to a seventh aspect of the present invention, in the position detection device according to any one of the first to third aspects, the sensor unit is configured by a single magnetic sensor, and the adjustment circuit is configured so that the magnetic sensor is in an active state. The supply current to the is adjusted to be constant.

  The invention according to claim 8 is a position detection device, comprising: a sensor unit that detects magnetism from a magnetic force generator; and an output value from the sensor unit, wherein the magnetic force generator and the sensor unit Position deriving means for deriving a relative position between them and outputting a position signal indicating the relative position to an arithmetic circuit; and a sensor power source for applying a voltage larger than a driving voltage of the arithmetic circuit to one power supply terminal of the sensor unit And an adjustment circuit that adjusts an input value of the sensor unit in an active state and shuts off an upstream circuit between the sensor power supply and the one power supply terminal of the sensor unit in an inactive state. .

  According to a ninth aspect of the present invention, in the position detection device according to the first or eighth aspect, the arithmetic circuit further includes a limiter circuit that limits a voltage of the position signal before input to a predetermined range.

  The invention according to claim 10 is the position detection device according to claim 9, wherein the limiter circuit is instructed to transition between the active state and the inactive state, and the upstream circuit is connected / disconnected. And an instruction means for instructing the transition of the limiter circuit from the active state to the inactive state after a lapse of a predetermined time after the instruction to switch the connection of the upstream side circuit to the cutoff state. .

  The invention according to claim 11 is the position detection device according to claim 9, wherein the limiter circuit is instructed to transition between an active state and an inactive state, and the upstream circuit is connected / disconnected. Instructing means to perform switching, and after the predetermined time has elapsed after the instruction to shift the limiter circuit from the inactive state to the active state, the instruction means instructs to switch the upstream circuit from being disconnected to being connected. .

  According to a twelfth aspect of the present invention, in the position detection device according to any one of the eighth to eleventh aspects, the sensor unit is configured by a pair of magnetic sensor pairs arranged apart from each other, and the position derivation is performed. Means derives the relative position based on each output value from the set of magnetic sensor pairs, and the adjustment circuit adjusts each voltage applied to the set of magnetic sensor pairs in an active state; The sum of the magnitudes of the output values from the pair of magnetic sensor pairs is set to a constant value.

  The invention according to claim 13 is the position detection device according to any one of claims 1 to 12, wherein the arithmetic circuit is a microcomputer.

  Further, the invention of claim 14 is a camera shake correction mechanism, and the position detection device according to any one of claims 1 to 13 and the relative position of two objects that move relatively to correct camera shake, Detection means for detecting using the position detection device, and drive means for correcting camera shake by performing relative driving of the two objects based on a detection result by the detection means.

  Further, the invention of claim 15 is an imaging device, wherein the relative position of the position detection device according to any one of claims 1 to 13 and two objects that move relative to each other to correct camera shake, Detection means that detects using a position detection device, and drive means that corrects camera shake by performing relative driving of the two objects based on the detection result of the detection means.

  The invention of claim 16 is an image pickup apparatus, the image pickup optical system including a focus lens, the position detection apparatus according to any one of claims 1 to 13, and the position detection apparatus. Lens position indicating means for detecting the position of the focus lens and controlling the position of the focus lens.

  The invention of claim 17 is an image pickup apparatus, which is an image pickup optical system including a zoom lens, the position detection apparatus according to any one of claims 1 to 13, and the position detection apparatus. Lens position indicating means for detecting the position of the zoom lens and controlling the position of the zoom lens.

  According to the first aspect of the invention, when the adjustment circuit is in an inactive state, the upstream circuit is blocked by the switching circuit. Thereby, a voltage larger than the drive voltage is not applied to the arithmetic circuit, and the arithmetic circuit can be prevented from being destroyed.

  According to the invention of claim 2, since the downstream circuit is shut off after the voltage is not completely applied to the one power supply terminal of the sensor unit, it is possible to effectively prevent the arithmetic circuit from being destroyed.

  According to the invention of claim 3, since the voltage is applied to one power supply terminal of the sensor section after the downstream circuit is completely connected, it is possible to effectively prevent the arithmetic circuit from being destroyed.

  According to the invention of claim 4, an error due to a temperature change can be compensated.

  According to the invention of claim 5, the relative position can be detected more accurately.

  According to the invention of claim 6, the configuration can be simplified.

  According to the seventh aspect of the invention, an error due to a temperature change can be compensated.

  According to the invention of claim 8, when the adjustment circuit is in an inactive state, the upstream circuit is shut off. Thereby, a voltage larger than the drive voltage is not applied to the arithmetic circuit, and the arithmetic circuit can be prevented from being destroyed.

  According to the ninth aspect of the invention, since the voltage of the position signal is limited to a predetermined range, a phenomenon in which a large voltage is applied to the arithmetic circuit can be effectively prevented.

  According to the invention of claim 10, since the limiter circuit is shifted to the inactive state after the voltage is not completely applied to one power supply terminal of the sensor unit, it is possible to effectively prevent the arithmetic circuit from being destroyed.

  According to the eleventh aspect of the present invention, since the voltage is applied to one power supply terminal of the sensor section after the limiter circuit is completely shifted to the active state, the arithmetic circuit can be effectively prevented from being destroyed.

  According to the invention of claim 12, an error due to a temperature change can be compensated.

  According to the invention of claim 13, destruction of the microcomputer can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<1-1. Outline of configuration>
In the first embodiment, a position detection apparatus 10A that detects a one-dimensional position will be described. This position detection device 10A is a magnetic linear encoder.

  FIG. 1 is a perspective view illustrating a physical arrangement of components included in the position detection device 10A, and FIG. 2 is a diagram schematically illustrating an electrical configuration of the position detection device 10A.

  As shown in FIG. 1, the position detection device 10 </ b> A includes a magnet 1 as one magnetic force generator and a sensor unit 2 that detects magnetism from the magnet 1. The sensor unit 2 includes two Hall elements (in other words, one Hall element pair (magnetic sensor pair)) 2a and 2b that are arranged apart from each other. The magnet 1 is composed of a prismatic permanent magnet. Both ends of the magnet 1 along the Z direction are magnetized with different polarities, and in the example shown in the figure, the upper surface side of the magnet 1 is an N pole and the lower surface side is an S pole.

  The Hall element pairs 2a and 2b are attached to a fixed-side object (fixed member) such as a device main body in which the position detection device 10A is employed. On the other hand, the magnet 1 is attached to a moving object (moving member) that moves relative to the fixed member. The magnet 1 attached to the moving member is movable in a predetermined direction (X direction in the drawing) with respect to the Hall element pair 2a, 2b attached to the fixed member. The X direction in which the magnet 1 can move coincides with the arrangement direction of the Hall element pairs 2a and 2b. The Hall element pair 2a, 2b may be attached to the moving member, and the magnet 1 may be attached to the fixed member. By attaching the magnet 1 that does not require electrical wiring to the moving member in this way, the wiring to the moving member is at least this element ( (Magnet) becomes unnecessary, and the degree of freedom in wiring design can be increased.

  In the position detection device 10 </ b> A, the relative position between the magnet 1 and the sensor unit 2 is detected. More specifically, the position (one-dimensional position) of the magnet 1 with respect to the Hall element pair 2a, 2b in the X direction as the arrangement direction of the pair of Hall element pairs 2a, 2b is derived.

  As shown in FIG. 2, the position detection device 10 </ b> A further includes a processing circuit 3 and a microcomputer 5. The processing circuit 3 performs arithmetic processing based on the output value from the sensor unit 2 to derive the position of the magnet 1, and outputs a position signal indicating the derived position of the magnet 1 to the microcomputer 5. The microcomputer 5 is an arithmetic circuit that performs an arithmetic operation based on the position of the magnet 1, and uses an input position signal for various controls and processes.

  Driving power is supplied from the three power supplies 71, 72, 73 to each part of the position detection apparatus 10 </ b> A. The drive voltage of the microcomputer 5 is 3.3V, and electric power is supplied from a 3.3V microcomputer power source 73. The Hall elements 2a and 2b are supplied with power from a 5V sensor power supply 71, which is higher than the driving voltage of the microcomputer 5, and the processing circuit 3 is also supplied with power from a 5V processing circuit power supply 72.

  The processing circuit 3 has the “position derivation function” for deriving the position of the magnet 1 described above, the “temperature compensation function” for eliminating the influence of changes in the environmental temperature, and the sensor unit 2 and each processing unit of the processing circuit 3. Are further provided with a “power control function” for performing control related to power supply from the power sources 71 and 72. Hereinafter, each of the three functions of the processing circuit 3 will be described in detail.

<1-2. Position derivation function>
First, the position derivation function of the processing circuit 3 will be described.

  FIG. 3 is a diagram showing the principle of magnetic detection by a Hall element which is a magnetoelectric conversion element utilizing the Hall effect. As shown in the figure, a predetermined input voltage Vin is applied between the positive and negative power supply terminals e1 and e2 of the Hall element 2a (2b) to cause a current (charged particle) to flow, and the current flows in the flowing direction. When a magnetic field is applied in a vertical direction (a direction along the axis BD in the drawing), charged particles receive Lorentz force in the magnetic field and are unevenly distributed on one of the Hall elements 2a (2b). Therefore, a potential difference (hereinafter referred to as “Hall electromotive force”) Vh corresponding to the strength of the magnetism (magnetic field) along the axis BD is generated in the Hall element 2a (2b). Therefore, by using the Hall electromotive force as an output value, the Hall element 2a (2b) functions as a magnetic sensor for measuring the magnetic strength along the axis BD.

  In the present embodiment, the position of the magnet 1 is detected using such a property of the Hall element. That is, in the arrangement state shown in FIG. 1, the magnetic strength detected by the two Hall elements 2 a and 2 b of the sensor unit 2 changes according to the relative position between the magnet 1 and the sensor unit 2. To do. Therefore, the position of the magnet 1 is detected based on the output values (Hall electromotive force) of these two Hall elements 2a and 2b.

  Hereinafter, a state in which the center position of the magnet 1 is exactly at the center position between the two Hall elements 2a and 2b is referred to as a “reference state”, and the position of the magnet 1 in this reference state is referred to as a “reference position”. The axis BD on which the Hall elements 2a and 2b detect magnetism is referred to as “detection axis” BD. Each Hall element 2a and 2b shown in FIG. 1 detects the magnetic flux density along the detection axis BD, and outputs Hall electromotive forces Vha and Vhb corresponding to the detected magnetic flux density.

  Here, it is assumed that the magnet 1 has moved in the + X direction from the reference position. In this case, the magnetic flux density distribution around the sensor unit 2 changes as the magnet 1 moves, and the Hall electromotive force Vha (more precisely, the absolute value) of one Hall element 2a is smaller than the reference state. The Hall electromotive force Vhb (more precisely, the absolute value) of the other Hall element 2b is larger than the reference state. Conversely, assuming that the magnet 1 moves in the −X direction from the reference position, the Hall electromotive force of one Hall element 2a is larger than the reference state, and the Hall electromotive force of the other Hall element 2b is the reference. The value is smaller than the state. Although the sign (positive / negative) of the Hall electromotive force is reversed depending on the direction of the detection axis BD of the Hall elements 2a and 2b, in this embodiment, as shown in FIG. 1, the detection axes BD of the Hall elements 2a and 2b are reversed. It is assumed that they are installed so that their directions are the same.

  Then, as shown in the following expression (1), if a difference (subtraction value) ΔV between the hall electromotive forces Vha and Vhb of the two Hall elements 2a and 2b is derived, this value ΔV is obtained as the Hall element pair 2a, The value represents the position of the magnet 1 with respect to 2b.

  That is, there is a one-to-one correspondence between the value ΔV and the position x of the magnet 1 (position in the X direction). If the position x is within a predetermined range, the position x is between the value ΔV and the position x. Has a relatively good linearity. Therefore, deriving the value ΔV substantially corresponds to deriving the position of the magnet 1 relative to the Hall element pair 2a, 2b.

  Even if the magnet 1 moves in any direction of the X direction, the increase in the Hall electromotive force of one Hall element is the same as the decrease in the Hall electromotive force of the other Hall element. The sum of the electromotive forces Vha and Vhb is a constant value.

  The position deriving function of the processing circuit 3 derives the relative position of the magnet 1 using the above principle. Among the processing units of the processing circuit 3 illustrated in FIG. 2, the differential amplification unit 31 (31a, 31b) and the subtraction unit 32 realize a position derivation function.

  That is, in the differential amplifier 31a, a Hall electromotive force Vha which is a difference between the output potentials Va1 and Va2 of one Hall element 2a is obtained, and in the differential amplifier 31b, the output potential Vb1 of the other Hall element 2b is obtained. The Hall electromotive force Vhb, which is the difference of Vb2, is obtained. Then, the subtractor 32 derives the difference ΔV (= Vha−Vhb) between these Hall electromotive forces Vha and Vhb, that is, the relative position of the magnet 1. The signal having the value ΔV from the subtracting unit 32 becomes a position signal Ls indicating the relative position of the magnet 1.

  The processing circuit 3 includes a filter unit 33 and a limiter unit 34 as a processing unit that implements an incidental function of the position derivation function. The position signal Ls output from the subtracting unit 32 passes through the filter unit 33 and the limiter unit 34, and then is output from the signal output terminal e4 of the processing circuit 3 to the microcomputer 5. The filter unit 33 is a low-pass filter and removes a noise component from the position signal Ls. Moreover, the limiter unit 34 limits the voltage of the position signal Ls to a predetermined range. That is, the voltage of the position signal Ls before being input to the microcomputer 5 is limited by the limiter unit 34 so as not to become larger than a predetermined value.

<1-3. Temperature compensation function>
Next, the temperature compensation function of the processing circuit 3 will be described. In general, the sensitivity (Hall element sensitivity) of the Hall elements 2a and 2b changes under the influence of the environmental temperature. On the other hand, the residual magnetic flux density of the magnet 1 also changes due to the environmental temperature. Therefore, the detection accuracy of the position derivation function of the processing circuit 3 is affected by the environmental temperature, and if the environmental temperature fluctuates, an error occurs in the value ΔV of the position signal Ls.

  In order to eliminate the influence of such environmental temperature changes, the temperature compensation function of the processing circuit 3 adjusts the input voltage to the sensor unit 2 (Hall elements 2a and 2b), and the above two Hall electromotive forces Vha and Vhb are Control is performed so that the sum (added value) is always the same. The Hall electromotive force changes depending on the magnitude of the input voltage as well as the magnetic strength. Therefore, the adjustment of the input voltage of the Hall elements 2a and 2b corresponds to the sensitivity adjustment of the Hall elements 2a and 2b.

  As shown in FIG. 2, the + side power terminal e1 and the − side power terminal e2 of the sensor unit 2 are common between the two Hall elements 2a and 2b, and the two Hall elements 2a and 2b are sensors. The power supply system from the power source 71 is electrically arranged in parallel. Therefore, the potential difference between these power supply terminals e1 and e2 becomes the input voltage Vin applied to each of the two Hall elements 2a and 2b. The temperature compensation function of the processing circuit 3 adjusts this input voltage Vin.

  Here, the principle of temperature compensation for compensating the error of the value ΔV according to the environmental temperature will be described. In this description, it is assumed that the magnet 1 exists at a certain position x1 and does not move from this position x1 because only the environmental temperature T is a variable element.

  First, the Hall electromotive forces Vha and Vhb are regarded as functions of the environmental temperature T and are expressed as Vha (T) and Vhb (T), respectively. Hall electromotive forces Vha (T) and Vhb (T) can be expressed by the following equations (2) and (3).

  Here, Va0 represents the output value per unit input voltage of the Hall element 2a under the condition that the ambient temperature T is a standard temperature (reference temperature) T0 and the magnet 1 exists at the position x1, and Vb0 Represents an output value per unit input voltage of the Hall element 2b under the same conditions. Vin (T) represents the input voltage Vin as a function of the environmental temperature T, and α (T) represents a Hall element sensitivity coefficient (ratio of the Hall element sensitivity to the reference temperature T0 as a function of the environmental temperature T). ) And β (T) represents the residual magnetic flux density coefficient of the magnet 1 as a function of the ambient temperature T (ratio of the residual magnetic flux density with respect to the reference temperature T0).

  The temperature compensation function of the processing circuit 3 is controlled so that the added value (Vha + Vhb) of the two Hall electromotive forces Vha and Vhb becomes a constant value. Therefore, the following expression (4) is established.

  Substituting the right-hand side of equations (2) and (3) into each term of equation (4) and rearranging results in the following equation (5).

  Further, the value ΔV of the position signal Ls is expressed as ΔV (T) as a function of the environmental temperature T. The value ΔV (T1) at the environmental temperature T1 and the value ΔV (T2) at the environmental temperature T1 are expressed by the following equations (6) and (7) in consideration of the equations (2) and (3), respectively. It is expressed.

  Then, when the right side of Expression (5) is substituted into Vin (T2) of Expression (7) and Expression (6) is considered, the following Expression (8) is established.

  That is, the value ΔV (T1) of the position signal Ls at the environmental temperature T1 is equal to the value ΔV (T2) of the position signal Ls at the environmental temperature T2. That is, even if the environmental temperature T changes from T1 to T2, the value ΔV (T1) of the position signal Ls is constant. Further, in this description, it is assumed that the magnet 1 exists at a certain position x1, but the equation (8) is similarly established regardless of the position x of the magnet 1.

  As described above, when the added value (Vha + Vhb) of the two hall electromotive forces Vha and Vhb is controlled to be a constant value, even if the environmental temperature T changes, the value ΔV of the position signal Ls is a change in the environmental temperature T. It turns out that it is not influenced. The temperature compensation function of the processing circuit 3 uses this principle to compensate for an error in the value ΔV due to a change in environmental temperature. Among the processing units of the processing circuit 3 illustrated in FIG. 2, the addition unit 35, the adjustment calculation unit 36, and the voltage adjustment circuit 37 implement a temperature compensation function.

  The voltage adjustment circuit 37 is a circuit disposed between the negative power supply terminal e2 of the sensor unit 2 and the ground, and includes an NPN transistor 37t. The collector of the transistor 37t is connected to the negative power supply terminal e2 of the sensor unit 2, and the emitter is connected to the ground via a resistor. Therefore, if the base voltage of the transistor 37t is adjusted, Vce (collector-emitter voltage) fluctuates, whereby the input voltage Vin applied to the two Hall elements 2a and 2b is adjusted.

  As described above, the input voltage Vin is adjusted so that the sum of the two Hall electromotive forces Vha and Vhb becomes a constant value. That is, first, the addition unit 35 obtains an added value (Vha + Vhb) of the two Hall electromotive forces Vha and Vhb. Next, the obtained addition value (Vha + Vhb) is compared with a predetermined value Vct by the adjustment calculation unit 36. This value Vct is a value at which the added value (Vha + Vhb) should be constant.

  Then, the adjustment signal As based on the comparison result between the added value (Vha + Vhb) and the constant value Vct is output from the adjustment calculation unit 36 to the voltage adjustment circuit 37. With this adjustment signal As, the base voltage of the transistor 37t of the voltage adjustment circuit 37 is adjusted, and as a result, the input voltage Vin is adjusted. Specifically, when the added value (Vha + Vhb) is larger than the constant value Vct, an adjustment signal As that lowers the base voltage (in order to increase Vce) is output from the adjustment calculation unit 36 in order to reduce the input voltage Vin. Is done. Conversely, when the added value (Vha + Vhb) is smaller than the constant value Vct, an adjustment signal As that increases the base voltage (in order to reduce Vce) is output from the adjustment calculation unit 36 in order to increase the input voltage Vin. Is done. By such processing, the temperature compensation function of the processing circuit 3 controls the added value of the two Hall electromotive forces Vha and Vhb to a constant value.

<1-4. Power control function>
Next, the power control function of the processing circuit 3 will be described. Of the processing units of the processing circuit 3 shown in FIG. 2, the power control unit 38 and the switching circuit 39 realize the power control function. This power control function controls the power supply states of the processing units 31 to 36 of the processing circuit 3 and the Hall elements 2a and 2b.

  As shown in the figure, the power supply control unit 38 includes two output lines Pv and Sv. The power supply line Pv that is one output line is connected to each of the processing units 31 to 36 of the processing circuit 3, and the signal supply line Sv that is the other output line is connected to the switching circuit 39.

  The power supply line Pv is connected to the processing circuit power supply 72 via a switch inside the power supply control unit 38. Accordingly, power from the processing circuit power supply 72 is supplied to the processing units 31 to 36 of the processing circuit 3 via the power supply line Pv. This power supply / stop is switched by the power supply control unit 38.

  The switching circuit 39 is a circuit disposed between the sensor power supply 71 and the power supply terminal e1 on the + side of the sensor unit 2, and includes a PNP transistor 39t. The emitter of the transistor 39t is connected to the sensor power source 71, and the collector is connected to the power terminal e1 on the + side of the sensor unit 2.

  The signal supply line Sv described above is connected to the base of the transistor 39t. The switching signal Ss is output from the power supply control unit 38 to the base of the transistor 39t via the signal supply line Sv. This switching signal Ss connects / disconnects a circuit (hereinafter referred to as “upstream circuit”) between the emitter and collector of the transistor 39t, that is, between the sensor power supply 71 and the power supply terminal e1 on the + side of the sensor unit 2. (Closed / Open) is switched. Specifically, when the switching signal Ss is output, the upstream circuit is connected to supply power to the Hall elements 2a and 2b. At this time, 5 V, which is the voltage of the sensor power supply 71, is applied to the power supply terminal e1 on the + side of the sensor unit 2. On the contrary, when the switching signal Ss is not output, the upstream circuit is cut off, and the power to the Hall elements 2a and 2b is stopped.

  Supply / stop of power through the power supply line Pv by the power supply control unit 38 and output / non-output of the switching signal Ss through the signal supply line Sv are switched in response to an instruction signal from the microcomputer 5. . The microcomputer 5 outputs two instruction signals Cs1 and Cs2 to the power supply control unit 38. Then, the power supply control unit 38 switches power supply / stop according to the level (H / L) of the first instruction signal Cs1, and switches the signal according to the switching of the level (H / L) of the second instruction signal Cs2. Switch Ss output / non-output.

  When the first instruction signal Cs1 is at the H level, power is supplied through the power supply line Pv, whereby the processing units 31 to 36 of the processing circuit 3 are in an active state (on state). Conversely, when the first instruction signal Cs1 is at the L level, the supply of power through the power supply line Pv is stopped. Thereby, each process part 31-36 of the processing circuit 3 will be in an inactive state (off state). That is, the switching of the level of the first instruction signal Cs1 by the microcomputer 5 corresponds to a transition instruction between the active state and the inactive state of each of the processing units 31 to 36 including the limiter unit 34.

  Incidentally, in the active state of the adjustment calculation unit 36, the adjustment signal As is output from the adjustment calculation unit 36 to the voltage adjustment circuit 37. For this reason, the base current of the transistor 37t flows, the collector-emitter becomes conductive, and a circuit (hereinafter referred to as "downstream circuit") between the negative side power supply terminal e2 of the sensor unit 2 and the ground is connected. Is done. On the contrary, since the adjustment signal As is not output in the non-active state of the adjustment arithmetic unit 36, the base current of the transistor 37t does not flow, the collector-emitter of the transistor 37t is non-conductive, and the downstream circuit is shut off. . That is, the transistor 37t adjusts the input voltage Vin as described above in a state where the base current flows (hereinafter referred to as “active state”), and conversely, the state where the base current does not flow (hereinafter referred to as “inactive state”). In this case, the input voltage Vin is not adjusted and the downstream circuit is shut off.

  Thus, the active state / inactive state of the adjustment calculation unit 36 and the active state / inactive state of the voltage adjustment circuit 37 are linked. Therefore, the switching of the level of the first instruction signal Cs1 by the microcomputer 5 corresponds to an instruction to shift the voltage adjustment circuit 37 between the active state and the inactive state.

  When the second instruction signal Cs2 is at the H level, the switching signal Ss is output through the signal supply line Sv, and the upstream circuit is connected by the switching circuit 39. Conversely, when the second instruction signal Cs2 is at the L level, the switching signal Ss is not output, and the upstream circuit is blocked by the switching circuit 39. Therefore, the switching of the level of the second instruction signal Cs2 by the microcomputer 5 corresponds to a switching instruction of energization / cutoff of the upstream circuit.

<1-5. Cut off upstream circuit in inactive state>
By the way, in the position detection device 10A, when the first instruction signal Cs1 is set to the L level and the processing units 31 to 37 of the processing circuit 3 are inactivated, the second instruction signal Cs2 is always set to the L level. The upstream circuit is shut off by 39. This is to prevent destruction of the microcomputer 5.

  Here, it is assumed that the upstream circuit connection is maintained in the inactive state of the processing units 31 to 37 of the processing circuit 3. In this case, since the upstream circuit is connected, the voltage 5 V of the sensor power supply 71 is applied to the power supply terminal e1 on the + side of the sensor unit 2. On the other hand, since the voltage adjustment circuit 37 is in an inactive state, the downstream circuit is blocked. For this reason, current does not flow from the + side power supply terminal e1 to the − side power supply terminal e2, but current tends to flow to the terminal e3 for outputting the Hall electromotive force of the Hall elements 2a and 2b.

  An equivalent circuit of the Hall elements 2a and 2b between the positive-side power supply terminal e1 and the terminal e3 is a resistor. Further, the differential amplifier 31, subtractor 32, filter 33, and limiter 34 in the inactive state function as resistors. Therefore, the power supply terminal e1 on the + side of the sensor unit 2 to the signal output terminal e4 of the processing circuit 3 functions as a simple resistor. The value of this resistance is very small compared to the internal resistance value of the microcomputer 5.

  As a result, the voltage applied to the + side power supply terminal e1 of the sensor unit 2 is applied to the signal output terminal e4 of the processing circuit 3 almost as it is. That is, the voltage 5 V of the sensor power supply 71 is applied to the microcomputer 5. As described above, the drive voltage of the microcomputer 5 is 3.3V, and the voltage 5V of the sensor power supply 71 is larger than this drive voltage. For this reason, when the voltage of the sensor power supply 71 is applied in this way, the microcomputer 5 may be destroyed.

  On the other hand, if the upstream circuit is always cut off in the inactive state of the processing units 31 to 37 of the processing circuit 3 as in the position detection device 10A of the present embodiment, the power supply on the + side of the sensor unit 2 Since no voltage is applied to the terminal e1, such destruction of the microcomputer 5 can be prevented.

  In the active state of the processing units 31 to 37 of the processing circuit 3, since the voltage adjustment circuit 37 is in an active state and the downstream circuit is connected, the positive side power supply terminal e1 of the sensor unit 2 is connected to the negative side. Current flows to the power supply terminal e2. Therefore, the voltage of the sensor power supply 71 is not directly applied to the microcomputer 5. Even if the voltage (ΔV) of the position signal Ls becomes a relatively large value due to some influence, this voltage is limited by the limiter unit 34 so as not to become larger than a predetermined value. Therefore, in the active state of the voltage adjustment circuit 37 and the limiter unit 34, there is no possibility that a voltage higher than the drive voltage is applied to the microcomputer 5.

<1-6. Instruction signal switching timing>
As described above, in the position detection device 10A, when the first instruction signal Cs1 is set to L level, the second instruction signal Cs2 is always set to L level. However, they are not switched at the same timing.

  FIG. 4 is a time chart showing changes in the levels of the instruction signals Cs1 and Cs2 when the instruction signals Cs1 and Cs2 are switched from the H level to the L level (for example, when the power of the position detection device 10A is turned off). As shown in the figure, first, the second instruction signal Cs2 is switched from the H level to the L level (time point Tp1). Then, after elapse of a predetermined time Wt1 from this time point Tp1, the first instruction signal Cs1 is switched from the H level to the L level (time point Tp2). That is, after an instruction for switching from connection to disconnection of the upstream circuit is made in advance, after the elapse of a predetermined time Wt1, an instruction to shift the voltage adjustment circuit 37 and the limiter unit 34 from the active state to the inactive state is issued. It will be.

  Since the switching circuit 39 mainly composed of bipolar transistors has a low response speed, the upstream circuit is energized for a while after the second instruction signal Cs2 is switched to the L level. Therefore, if the instruction signals Cs1 and Cs2 are simultaneously switched to the L level, the voltage of the sensor power supply 71 is applied to the power supply terminal e1 on the + side of the sensor unit 2 regardless of the voltage adjustment circuit 37 and the limiter unit 34 being inactive. May be applied and the microcomputer 5 may be destroyed.

  On the other hand, as shown in FIG. 4, the timing at which the first instruction signal Cs1 is set to the L level is delayed by a predetermined time Wt1 from the timing at which the second instruction signal Cs2 is set to the L level. After the voltage is no longer applied to the power supply terminal e1, the voltage adjustment circuit 37 and the limiter unit 34 can be shifted to the inactive state. For this reason, destruction of the microcomputer 5 can be effectively prevented. The delay time Wt1 is set to, for example, about 5 μs in accordance with the response speed of the switching circuit 39.

  Even when the instruction signals Cs1 and Cs2 are switched from the L level to the H level (for example, when the position detection device 10A is turned on), the first instruction signal Cs1 and the second instruction signal Cs2 are set to the H level. The timing for switching is different.

  FIG. 5 is a time chart showing changes in the levels of the instruction signals Cs1 and Cs2 in this case. As shown in the figure, first, the first instruction signal Cs1 is switched from the L level to the H level (time point Tp3). Then, after the elapse of a predetermined time Wt2 from this time point Tp3, the second instruction signal Cs1 is switched from the L level to the H level (time point Tp4). That is, after the voltage adjustment circuit 37 and the limiter unit 34 are instructed to shift from the inactive state to the active state in advance, after the elapse of the predetermined time Wt2, the upstream circuit is instructed to be switched to being disconnected. It will be.

  Since the voltage adjustment circuit 37 and the limiter unit 34 are mainly composed of bipolar transistors (or operational amplifiers using the same), the response speed is low. For this reason, even if the first instruction signal Cs1 is switched to the H level, they are not instantaneously activated. Therefore, if the instruction signals Cs1 and Cs2 are simultaneously switched to the H level, the voltage of the sensor power supply 71 is applied to the power supply terminal e1 on the + side of the sensor unit 2 even though the voltage adjustment circuit 37 and the limiter unit 34 are inactive. If applied, the microcomputer 5 may be destroyed.

  On the other hand, as shown in FIG. 5, the voltage adjustment circuit 37 and the limiter are delayed by delaying the timing at which the second instruction signal Cs2 is at the H level by a predetermined time Wt2 from the timing at which the first instruction signal Cs1 is at the H level. The voltage can be applied to the power terminal e1 on the + side of the sensor unit 2 after the unit 34 has completely shifted to the active state. For this reason, destruction of the microcomputer 5 can be effectively prevented. The delay time Wt2 is set to about 5 μs, for example, in accordance with the response speeds of the voltage adjustment circuit 37 and the limiter unit 34.

  As described above with respect to the first embodiment, in the position detection device 10A, the upstream circuit between the sensor power supply 71 and the sensor unit 2 is always used when the voltage adjustment circuit 37 and the limiter unit 34 are inactive. Is cut off by the switching circuit 39. As a result, a voltage larger than the drive voltage is not applied to the microcomputer 5, and the microcomputer 5 can be prevented from being destroyed.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. The second embodiment is a modification of the first embodiment. In the present embodiment, one voltage adjustment circuit is used for both the purpose of adjusting the input voltage Vin and shutting off the upstream circuit. Below, it demonstrates centering on difference with 1st Embodiment.

  FIG. 6 is a diagram schematically illustrating an electrical configuration of the position detection apparatus 10B according to the present embodiment. In the present embodiment, the voltage adjustment circuit 61 is arranged in the upstream circuit between the sensor power supply 71 and the positive power supply terminal e1 of the sensor unit 2. Further, the downstream circuit between the negative power supply terminal e2 of the sensor unit 2 and the ground is directly connected.

  The voltage adjustment circuit 61 includes a PNP-type transistor 61t, the emitter of which is connected to the sensor power supply 71, and the collector of which is connected to the power supply terminal e1 on the + side of the sensor unit 2. The adjustment signal As is output from the adjustment calculation unit 36 to the base of the transistor 61t. With this adjustment signal As, the base current of the transistor 61t flows, the base voltage is adjusted, and the input voltage Vin of the Hall elements 2a and 2b is adjusted. That is, the voltage adjustment circuit 61 functions as a part of the temperature compensation function of the processing circuit 3 in the active state.

  In this embodiment, since the PNP transistor 61t is employed, the base of the transistor 61t is pulled up so as to have the same voltage as the sensor power supply 71 when the adjustment signal As is not output. The magnitude relationship of the base voltage with respect to the adjustment of the input voltage Vin is opposite to that of the first embodiment. Specifically, when the added value (Vha + Vhb) is larger than the constant value Vct, the base voltage is raised in order to reduce the input voltage Vin (in order to increase Vce). Conversely, when the added value (Vha + Vhb) is smaller than the constant value Vct, the base voltage is lowered to increase the input voltage Vin (to decrease Vce).

  Further, in the state where the adjustment signal As is not output from the adjustment calculation unit 36, the base circuit does not flow, and therefore the upstream circuit is shut off. That is, the voltage adjustment circuit 61 blocks the upstream circuit in the inactive state. Therefore, the voltage adjustment circuit 61 according to the present embodiment is used for both functions of the voltage adjustment circuit 37 and the switching circuit 39 according to the first embodiment.

  Thus, in the present embodiment, since the voltage adjustment circuit 61 is arranged in the upstream circuit, the upstream circuit is always cut off when the voltage adjustment circuit 61 is in an inactive state. For this reason, no voltage is applied to the positive-side power supply terminal e1 of the sensor unit 2, and the destruction of the microcomputer 5 is prevented.

  Meanwhile, even if the voltage (ΔV) of the position signal Ls becomes a relatively large value due to some influence in the active state of the voltage adjustment circuit 61, this voltage is limited by the limiter unit 34. For this reason, even when the voltage adjustment circuit 61 is in an active state, there is no possibility that a voltage higher than the drive voltage is applied to the microcomputer 5.

  The power control unit 38 of the present embodiment also includes two output lines Pva and Pvb, both of which are power supply lines for supplying power from the processing circuit power supply 72. The first supply line Pva is connected to the processing units 31 to 35 of the processing circuit 3. Therefore, the active state and the inactive state of the processing units 31 to 35 of the processing circuit 3 including the limiter unit 34 are switched by the supply / stop of the power through the first supply line Pva.

  On the other hand, the second supply line Pvb is connected only to the adjustment calculation unit 36. Also in the present embodiment, the active state / inactive state of the adjustment calculation unit 36 and the active state / inactive state of the voltage adjustment circuit 61 are linked. Therefore, the adjustment calculation unit 36 and the voltage adjustment circuit 61 are switched between the active state and the inactive state by supplying / stopping the power through the second supply line Pvb.

  Also in this embodiment, the microcomputer 5 outputs two instruction signals Cs 1 and Cs 2 to the power supply control unit 38. Then, the power supply control unit 38 switches the supply / stop of power via the first supply line Pva according to the level (H / L) of the first instruction signal Cs1, and the level (H / L) of the second instruction signal Cs2. ) Is switched to supply / stop electric power via the second supply line Pvb.

  When the instruction signals Cs1, Cs2 are switched from the H level to the L level, the levels of the instruction signals Cs1, Cs2 are switched as shown in FIG. Therefore, after a predetermined time Wt1 has elapsed after the instruction to switch the upstream circuit from connection to disconnection (instruction to shift the voltage adjustment circuit 61 from the active state to the inactive state) is made in advance, the limiter unit 34 is activated. A transition instruction from the state to the inactive state is performed.

  Further, when the instruction signals Cs1, Cs2 are switched from the L level to the H level, the levels of the instruction signals Cs1, Cs2 are switched as shown in FIG. Therefore, after the limiter unit 34 is instructed to shift from the inactive state to the active state in advance, after the elapse of the predetermined time Wt2, the upstream circuit is disconnected and switched to the connection instruction (the voltage adjustment circuit 61 is inactive). (Transition instruction from state to active state) is performed. Thereby, also in this Embodiment, destruction of the microcomputer 5 is prevented effectively.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described. The third embodiment is a modification of the first embodiment. In the present embodiment, the sensor unit 2 has only one Hall element. Below, it demonstrates centering on difference with 1st Embodiment.

  FIG. 7 is a diagram schematically illustrating an electrical configuration of the position detection device 10C according to the present embodiment. In the present embodiment, the sensor unit 2 is composed of only one Hall element 2c, and the Hall electromotive force Vhc, which is the difference between the output potentials Vc1 and Vc2, is set as the relative position of the magnet 1 with respect to the Hall element 2c. . That is, the Hall electromotive force Vhc is directly used as the value of the position signal Ls indicating the relative position of the magnet 1.

  Therefore, the processing circuit 3 includes only one differential amplifying unit 31 for obtaining the Hall electromotive force Vhc as a position derivation function, and does not include the subtracting unit 32. The position signal Ls output from the differential amplifying unit 31 passes through the filter unit 33 and the limiter unit 34, and then is output from the signal output terminal e4 of the processing circuit 3 to the microcomputer 5.

  In the present embodiment, the supply current from the sensor power supply 71 to the Hall element 2c is adjusted to a constant value in order to eliminate the influence of changes in the environmental temperature. Therefore, the processing circuit 3 includes a constant current circuit 62 as a temperature compensation function.

  The constant current circuit 62 is disposed in a downstream circuit between the negative power supply terminal e2 of the sensor unit 2 and the ground, and is mainly composed of an operational amplifier 62a, a transistor 62t, and a resistor R1. The collector of the transistor 62t is connected to the negative side power supply terminal e2 of the sensor unit 2, and the emitter is connected to the ground via a resistor R1. The current flowing between the emitter and the collector is adjusted to a constant value defined by the voltage Vref of the + input terminal of the operational amplifier 62a and the resistor R1. That is, the current supplied to the Hall element 2c is adjusted to a constant value.

  The constant current circuit 62 shifts between an active state and an inactive state according to the power supplied to the operational amplifier 62a. The constant current circuit 62 adjusts the current supplied to the Hall element 2c to a constant value as described above in the active state, but shuts down the downstream circuit in the inactive state.

  The configurations of the power controller 38 and the switching circuit 39 are the same as those in the first embodiment. However, the power supply line Pv is connected to the differential amplifier 31, the filter 33, the limiter 34, and the operational amplifier 62 a of the constant current circuit 62 of the processing circuit 3. Therefore, the active state and the inactive state of the differential amplifier unit 31, the filter unit 33, the limiter unit 34, and the constant current circuit 62 are switched by supplying / stopping the power via the power supply line Pv.

  Also in the present embodiment, when the connection of the upstream circuit is maintained in the inactive state of the limiter unit 34 and the constant current circuit 62, the microcomputer 5 may be destroyed. Therefore, the upstream circuit is always cut off by the switching circuit 39 when the limiter unit 34 and the constant current circuit 62 are inactive.

  Also in the present embodiment, the microcomputer 5 outputs two instruction signals Cs 1 and Cs 2 to the power supply control unit 38. Then, the power supply control unit 38 switches power supply / stop according to the level (H / L) of the first instruction signal Cs1, and switches the signal according to the switching of the level (H / L) of the second instruction signal Cs2. Switch Ss output / non-output.

  When the instruction signals Cs1, Cs2 are switched from the H level to the L level, the levels of the instruction signals Cs1, Cs2 are switched as shown in FIG. Therefore, after the instruction for switching from the connection of the upstream circuit to the disconnection is made in advance, and after the elapse of the predetermined time Wt1, an instruction to shift the constant current circuit 62 and the limiter unit 34 from the active state to the inactive state is issued. It will be.

  Further, when the instruction signals Cs1, Cs2 are switched from the L level to the H level, the levels of the instruction signals Cs1, Cs2 are switched as shown in FIG. Accordingly, after the constant current circuit 62 and the limiter unit 34 are instructed to shift from the inactive state to the active state in advance, after the elapse of the predetermined time Wt2, the upstream circuit is instructed to be switched from being disconnected to being connected. It will be. Thereby, also in this Embodiment, destruction of the microcomputer 5 is prevented effectively.

<4. Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described. The fourth embodiment is a modification of the first embodiment. In the present embodiment, the two-dimensional relative position of the magnet 1 is derived. Below, it demonstrates centering on difference with 1st Embodiment.

  FIG. 8 is a perspective view showing a physical arrangement of components included in the position detection device 10D of the present embodiment, and FIG. 9 is a diagram schematically showing an electrical configuration of the position detection device 10D. is there.

  As shown in FIG. 8, the position detection device 10D includes one magnet 1 and four Hall elements 2a, 2b, 2c, 2d, in other words, two Hall element pairs (magnetic sensor pairs) (2a , 2b), (2c, 2d). The arrangement of these Hall element pairs is relatively fixed. One set of Hall element pairs 2a and 2b are arranged apart from each other in the X direction, and another set of Hall element pairs 2c and 2d are arranged apart from each other in the Y direction. That is, the arrangement direction (X direction) of the Hall element pairs 2a and 2b and the arrangement direction (Y direction) of the Hall element pairs 2c and 2d are orthogonal to each other.

  The hall element pairs 2a and 2b function as one sensor unit 2, and the hall element pairs 2c and 2d function as another sensor unit 2. The magnet 1 is movable in both directions of the X direction and the Y direction with respect to these two sets of sensor units 2 fixed relatively. In the position detection device 10D, a two-dimensional relative position of the moving magnet 1 with respect to the two sets of sensor units 2 is detected.

  As shown in FIG. 9, in the position detection device 10D, two processing circuits 30 are provided so as to be compatible with two sets of sensor units 2. In one processing circuit 30, the position x in the X direction of the magnet 1 is derived based on the output values of the Hall element pairs 2a and 2b, and in the other processing circuit 30, the position y in the Y direction of the magnet 1 is derived. Is done. That is, the position detection device 10D includes two sets of detection units U1 and U2 that each detect the one-dimensional position of the magnet 1.

  Unlike the processing circuit 3 of the first embodiment, the processing circuit 30 does not have a “power supply control function” but has only a “position derivation function” and a “temperature compensation function”. Therefore, the configuration of the processing circuit 3 is a configuration obtained by removing the switching circuit 39 and the power supply control unit 38 from the configuration of the processing circuit 3 shown in FIG. That is, one detection unit includes one sensor unit 2 (one set of Hall elements), one position deriving function (including the limiter unit 34), and one temperature compensation function (including the voltage adjustment circuit 37). It will be comprised including.

  Therefore, the position signal Ls indicating the relative position is output to the microcomputer 5 from the processing circuit 30 of each of the detection units U1 and U2. Specifically, the processing circuit 30 of the detection unit U1 including the Hall element pair 2a and 2b outputs a position signal Ls1 indicating the relative position of the magnet 1 in the X direction, and the processing of the detection unit U2 including the Hall element pair 2c and 2d. The circuit 30 outputs a position signal Ls2 indicating the relative position of the magnet 1 in the Y direction. That is, the two-dimensional relative position of the magnet 1 is input to the microcomputer 5. The input voltage Vin is adjusted by the voltage adjustment circuit 37 so that the added value of the output values of the sensor units 2 (Hall element pairs) of the units U1 and U2 becomes a constant value.

  Further, in the position detection device 10D, the switching circuit 39 and the power supply control unit 38 responsible for the “power supply control function” are configured independently of the detection units U1 and U2. The configuration of these “power control functions” is substantially the same as that of the first embodiment, and operates based on the instruction signals Cs1 and Cs2 from the microcomputer 5 as in the first embodiment. However, the power supply line Pv of the power supply control unit 38 is connected to the processing circuits 30 of both of the two detection units U1 and U2, and the switching circuit 39 includes both sensor units 2 of the detection units U1 and U2. Is connected to the power terminal e1 on the + side.

  That is, in the present embodiment, one switching circuit 39 and one power supply control unit 38 are shared by both detection units U1 and U2. Thereby, the configuration can be simplified and control can be facilitated as compared with the case where each of the detection units U1 and U2 is provided with a “power control function”.

  In addition, although the position detection apparatus 10D of this Embodiment has two detection units, you may have three or more detection units. Regardless of the number of detection units, the relative position of the magnet 1 with respect to the sensor unit 2 can be obtained with high accuracy by relatively fixing the arrangement of the sensor units 2 (Hall element pairs) among the plurality of detection units. .

  In addition, the arrangement direction of the Hall element pairs may be different among the plurality of detection units, or may be parallel. When the arrangement direction of the Hall element pair is made different between the plurality of detection units, the relative position of the magnet 1 can be obtained in a plurality of dimensions. On the other hand, when the arrangement direction of the Hall element pair is parallel between the plurality of detection units, the position of the magnet 1 in the arrangement direction can be accurately measured.

  Further, the position detection device 10D according to the present embodiment includes two detection units each for adjusting the input voltage Vin of the sensor unit 2. However, each of the position detection devices 10D includes a sensor unit as in the third embodiment. Two detection units that adjust the supply current to 2 to a constant value may be provided.

<5. Fifth embodiment>
Next, a fifth embodiment of the present invention will be described. In the present embodiment, a specific usage form of the position detection device is illustrated. Here, the case where the position detection device as described above is used for the camera shake correction mechanism of the imaging device will be described in detail. Note that the present invention can be applied to both an imaging device (such as a digital still camera) that captures still images and an imaging device (such as a digital movie camera) that captures moving images.

  FIG. 10 is a diagram illustrating an image pickup apparatus (here, a digital still camera) 300A having a camera shake correction function. The imaging apparatus 300 </ b> A includes a camera body 60, a lens barrel 70 in which a plurality of lenses 40 are incorporated, a gyro sensor 50 fixed to a side surface portion of the lens barrel 70, and a camera shake correction device 100 attached to an end surface of the lens barrel 70. And is configured.

  The camera shake correction apparatus 100 is provided with an image pickup device 16 such as a CCD. The image pickup device 16 is placed in an XY plane perpendicular to the optical axis L in accordance with the shake of the image pickup device 300A detected by the gyro sensor 50. The camera shake is corrected by moving the lens with. For example, when the imaging apparatus 300A is shaken during the photographing by the imaging apparatus 300A and the optical axis L incident on the lens barrel 70 is deviated as indicated by an arrow D1 in FIG. The shift of the optical axis L is corrected by moving as indicated by the arrow D2. The camera shake correction device 100 has a function as a position detection device. At the time of camera shake correction, the position detection function detects the current position of the image sensor 16 in the XY plane, and the position information is used as the image sensor 16. Is used as feedback information for controlling the position of the head with high accuracy.

  FIG. 11 is an exploded perspective view of the camera shake correction apparatus 100. As shown in FIG. 11, the camera shake correction apparatus 100 mainly includes a base plate 12 fixed to an end surface of a lens barrel 70, a first slider 14 that moves in the X-axis direction with respect to the base plate 12, and a first slider. The three members of the second slider 13 moving in the Y-axis direction with respect to 14 are combined.

  The base plate 12 is formed using an annular metal frame 122 having an opening 121 at the center as a base material, and the metal frame 122 is fixed to the lens barrel 70. The base plate 12 has a configuration in which a metal frame 122 is provided with a first actuator 123 extending in the X-axis direction and a magnetic sensor unit 22 configured by incorporating a plurality of Hall elements. . In addition, a first spring hook 124 is formed at a predetermined position on the periphery of the metal frame 122, and L-shaped substrate holders 125 are formed at a plurality of locations on the periphery.

  The second slider 13 includes a resin-made frame 132 having an opening 131 that can accommodate and fix the image sensor 16 at the center thereof, and the second slider 13 extends in the Y-axis direction to the frame 132. The actuator 133, the hard ball receiver 134 that loosely fits the hard ball 19 on both sides in the Z-axis direction, and the magnet support portion 21 for supporting the magnet are provided. The magnet support portion 21 is formed on the outer side of the second actuator 133 with respect to the opening 131 and at a position facing the magnetic sensor unit 22 provided on the base plate 12.

  FIG. 12 is an enlarged view of a main part when the magnet support portion 21 is viewed from the front. As shown in FIG. 12, the magnet support portion 21 is formed by a plate-like magnet support arm 212 extending outward from a wall surface 211 formed outside the second actuator 133, and the magnet support arm 212. A magnet receiving portion 213 is provided on the lower surface side of the tip portion. The magnet receiving portion 213 can be fixed by inserting the magnet 23 therein. And as shown in FIG. 12, the magnet 23 fixed to the lower surface side of the magnet support arm 212 is arrange | positioned in the position facing the magnetic sensor unit 22 of the base board 12. As shown in FIG. The lower surface of the magnet 23 and the surface (upper surface) of the magnetic sensor unit 22 are provided so as to be substantially parallel to each other.

  Returning to FIG. 11, the first slider 14 is formed by using an aluminum annular frame 142 in which an opening 141 for accommodating the second slider 13 is formed at the center thereof as a base material. The first friction coupling portion 143, the second friction coupling portion 144, and the second spring hook 145 are provided. The first friction coupling portion 143 is provided at a position facing the first actuator 123 of the base plate 12, and the second friction coupling portion 144 is provided at a position facing the second actuator 133 of the second slider 13. Further, the second spring hook 145 is provided at a position facing the first spring hook 124 of the base plate 12.

  As shown in FIG. 13, each of the first actuator 123 and the second actuator 133 includes a stationary member 81, a piezoelectric element 82, and a drive rod 83, and the stationary member 81 is fixed to the base plate 12 or the second slider 13. In addition, one end side of the piezoelectric element 82 is fixed to the stationary member 81 and the other end side is connected to the drive rod 83. The drive rod 83 is moved in an amount and direction according to the drive pulse applied to the piezoelectric element 82. At this time, the moving direction of the drive rod 83 is a direction in which each actuator is extended, that is, a direction indicated by an arrow 84 in the example of FIG.

  When the camera shake correction apparatus 100 as described above is assembled, the image sensor 16 is fitted and fixed in the opening 131 of the second slider 13, and the drive rod 83 of the first actuator 123 and the first friction coupling portion 143. Are frictionally coupled, and the drive rod 83 of the second actuator 133 and the second frictional coupling portion 144 are frictionally coupled. Further, a spring 18 is installed between the first spring hook 124 and the second spring hook 145, and the base plate 12 and the first slider 14 are urged by the spring 18 so as to approach each other. At this time, the second slider 13 is sandwiched between the base plate 12 and the first slider 14 via the hard sphere 19. Accordingly, the base plate 12, the second slider 13, and the first slider 14 are overlapped in this order from the Z-axis negative direction side to the positive direction side, and these members 12, 13, and 14 are arranged.

  When the drive rod 83 of the first actuator 123 moves in a state in which the camera shake correction apparatus 100 is assembled, the first slider 14 is moved relative to the base plate 12 by the movement of the first friction coupling portion 143 that is frictionally coupled thereto. To move in the X-axis direction. At this time, the second slider 13 also moves in the X-axis direction with respect to the base plate 12 in accordance with the movement of the first slider 14. Further, when the drive rod 83 of the second actuator 133 moves, the second slider 13 moves in the Y-axis direction with respect to the first slider 14 by the movement of the second friction coupling portion 144 that frictionally couples to the drive rod 83. At this time, since the first slider 14 is not moved with respect to the base plate 12, the second slider 13 is independently moved in the Y-axis direction with respect to the base plate 12.

  Therefore, in the camera shake correction apparatus 100, each of the first slider 14 and the second slider 13 holds the image sensor 16 and is movable with respect to the base plate 12 serving as a fixed member (fixed body). Mobile body). The first slider 14 only moves linearly along the X-axis direction with respect to the base plate 12, but the second slider 13 moves in the Y-axis direction in addition to the movement of the first slider in the X-axis direction. Therefore, the second slider 13 is configured to be movable in the XY plane perpendicular to the optical axis while holding the image sensor 16.

  The drive rods 83 of the first actuator 123 and the second actuator 133 also have a function as guide means for guiding the linear movement of the second slider 13 in the X axis direction and the Y axis direction, respectively. .

  FIG. 14 is a cross-sectional view taken along the line II in FIG. 11 and shows a state in which the camera shake correction device 100 is assembled and attached to the lens barrel 70. The camera shake correction apparatus 100 supports a magnetic sensor unit 22 provided on the base plate 12 and a magnet 23 attached to the second slider 13 in close proximity to each other, and the magnetic sensor unit 22 is a magnet. It is arranged so that the change of the magnetic field generated by 23 can be detected well. As described above, the second slider 13 can move in the XY plane, and the position of the magnet 23 with respect to the magnetic sensor unit 22 varies as the second slider 13 moves. When the position of the magnet 23 with respect to the magnetic sensor unit 22 varies in the XY plane, the magnetic field detected by the magnetic sensor unit 22 changes with the movement of the second slider 13. Therefore, when the magnetic sensor unit 22 detects a change in the magnetic field generated by the magnet 23, the movement state (that is, the current position) of the second slider 13 can be detected. The magnetic sensor unit 22 and the magnet Reference numeral 23 denotes a position detection mechanism 20 for detecting the position of the second slider 13 with respect to the base plate 12. Since the magnet 23 does not need to be electrically wired, the position detection mechanism 20 is useful in that the wiring work is remarkably saved.

  A first substrate 41 is provided on the back side (Z-axis positive direction side) of the image sensor 16 provided on the second slider 13 via the heat radiating plate 17, and the image sensor 16 is attached to the first substrate 41. It is connected. Therefore, the first substrate 41 moves in the X direction and the Y direction integrally with the second slider 13. The second substrate 42 is fixed to the substrate holder 125 of the base plate 12. The first substrate 41 and the second substrate 42 are arranged so as to overlap in the optical axis direction (Z-axis direction), and the first substrate 41 moves in parallel to the second substrate 42 by the movement of the second slider 13. . The first substrate 41 and the second substrate 42 are connected to each other by a flexible substrate 43 having flexibility so that signals can be transmitted and received.

  The magnetic sensor unit 22 is connected to the second substrate 42 by a signal line (not shown). In addition, a gyro sensor 50 that detects a blur of the imaging device 300A and outputs an angular velocity signal related to a blur in the X-axis direction and the Y-axis direction is also connected to the second substrate 42 by a signal line (not shown).

  Elements and circuits for controlling the image sensor 16 are arranged on the first substrate 41, and an output signal (image signal) from the image sensor 16 is given to the second substrate 42 via the flexible substrate 43. On the second substrate 42, a circuit for processing an output signal from the image sensor 16, a circuit for processing a signal from the magnetic sensor unit 22 for detecting the position of the second slider 13, and the like are arranged. Control circuit (including a microcomputer or the like) for driving and controlling the first and second actuators 123 and 133 based on the position signal (X coordinate value and Y coordinate value) of the sensor and the angular velocity signal input from the gyro sensor 50. Circuit). The second substrate 42 outputs an image signal acquired by the image sensor 16 to a control circuit provided inside the image sensor 16 and is different from the camera shake correction apparatus 100, and a signal line (not shown). A drive signal (drive pulse) is sent to each of the first and second actuators 123 and 133 connected in the above.

  In the circuit arrangement as described above, since the magnet 23 provided on the second slider 13 does not require electrical wiring, the wiring pattern between the first substrate 41 and the second substrate 42 can be made relatively simple. As a result, the degree of freedom in designing the arrangement of parts and the routing of wiring is increased, and the work efficiency during assembly is improved. In particular, since the wiring for the moving member may become a resistance to the movement of the moving member, it is desirable to avoid the wiring to the moving member as much as possible. In the present embodiment, since the magnet 23 is provided on the second slider 13 which is a moving member, the wiring of the position detection mechanism 20 does not hinder the movement of the second slider 13 and is in a suitable arrangement.

  Next, the operation of the above-described camera shake correction apparatus 100 will be described. FIG. 15 is a block diagram showing an electrical configuration of the drive control circuit of the camera shake correction apparatus 100 according to the present embodiment. This control circuit includes a gyro sensor 50 that detects blurring of the optical axis L incident on the lens barrel 70 and outputs an angular velocity signal, and a magnetic sensor unit 22 that detects the position of the second slider 13 (imaging device 16). A processing circuit 24 that processes the above-described signal, a microcomputer 101 that performs overall control of camera shake correction, calculates a driving amount based on various input signals, and a driving signal from the microcomputer 101 And a drive circuit 102 for generating a drive pulse of a predetermined frequency. The drive pulse generated by the drive circuit 102 is output to the first and second actuators 123 and 133, and the first and second sliders 14 and 13 move along the extending direction of each actuator.

  When the camera body 60 is shaken as indicated by an arrow D1, the gyro sensor 50 detects angular velocities in two axial directions (X-axis direction and Y-axis direction) and outputs the angular velocities to the microcomputer 101.

  When the microcomputer 101 receives the angular velocity signal from the gyro sensor 50, the microcomputer 101 calculates the moving amount and moving speed of the image due to the blur on the imaging device 16 (on the imaging surface) from the focal length signal of the optical system. Then, a supply voltage of a predetermined frequency to be applied to the first and second actuators 123 and 133 is determined from the calculated moving speed and the current position of the second slider 13 (imaging device 16). That is, the microcomputer 101 detects the position (current position) where the second slider 13 (imaging element 16) is present based on the signal input from the magnetic sensor unit 22 and the angular velocity signal input from the gyro sensor 50. The image sensor 16 determined based on the above is compared with the position (target position) where the image sensor 16 should be, and feedback control is performed to drive the sliders 13 and 14 so that the image sensor 16 moves to the position where the image sensor 16 should be.

  The drive circuit 102 receives a signal from the microcomputer 101 and outputs a drive pulse having a frequency of about 70% of the resonance frequency of the actuators 123 and 133. The drive pulse is applied to the piezoelectric element 82 and moves the first and second sliders 13 and 14 along the drive rod 83. Specifically, the member 13 (or 14) frictionally coupled to the drive rod 83 is frictionally applied to the piezoelectric element 82 by applying a sawtooth wave drive pulse having a gently rising portion and a sudden falling portion. It can be moved in one direction by the action according to the magnitude relationship between the force and the inertial force. Conversely, by changing the waveform of the sawtooth wave applied to the piezoelectric element 82 and applying a drive pulse consisting of a rapid rise and a gentle fall, the member 13 (or 14) is now reversed. Can be moved in the direction.

  Thus, the first and second actuators 123 and 133 are configured as impact actuators, and the sliders 13 and 14 frictionally coupled to the drive rod 83 are moved on the drive rod 83 as the piezoelectric element 82 expands and contracts. Slide. When the drive pulse is applied to the first actuator 123 and the first slider 14 moves in the X-axis direction, the second slider 13 connected to the first slider also moves in the X-axis direction at the same time. When a drive pulse is applied to the second actuator 133, only the second slider 13 moves (self-runs) in the Y-axis direction independently of the first slider 14. The second slider 13 moves with little resistance and without fluctuation in the optical axis direction by the spring 18 between the first slider 14 and the base plate 12 and the rigid sphere 19 between the members. At this time, the flexible substrate 43 connecting the first substrate 41 and the second substrate 42 functions so as to absorb the movement of the second slider 13 due to the bent portion.

  As described above, the camera shake correction device 100 has a built-in function as a position detection device. As a characteristic configuration, the position detection mechanism 20 includes the magnetic sensor unit 22 and the magnet 23. In the present embodiment, a position detection mechanism 20 that does not require wiring for position detection is realized for at least one of the moving member and the fixed member.

  Each component of the position detection mechanism 20 corresponds to a component of the position detection device 10D (see FIGS. 8 and 9) according to the fourth embodiment. Specifically, the magnet 23 corresponds to the magnet 1, and the magnetic sensor unit 22 corresponds to two sets of sensor units 2 including four Hall elements 2 a to 2 d. The processing circuit 24 corresponds to the two processing circuits 30, the switching circuit 39, and the power supply control unit 38. Moreover, the microcomputer 101 shown in FIG. 15 bears the function of the microcomputer 5 in the position detection apparatus 10D of the fourth embodiment as a part of its function.

  Therefore, the imaging apparatus 300A provided with such a position detection mechanism (also referred to as a position detection apparatus) can obtain the same advantages as those of the fourth embodiment. Further, since the position detection device is a non-contact type, it is possible to obtain an advantage that the position detection device does not have to be a noise generation source in the imaging device.

  Further, here, the Hall elements 2a and 2b are arranged so that the sensor arrangement direction thereof substantially coincides with the moving direction (X-axis direction) of the first actuator 123, and the Hall element elements 2c and 2d are arranged in the second sensor arrangement direction. The actuator 133 is arranged so as to substantially coincide with the moving direction (Y-axis direction). For this reason, the coordinate system of the coordinate values detected by the magnetic sensor unit 22 substantially coincides with the coordinate system used for controlling the first and second actuators 123 and 133, and the coordinate system is used when performing signal processing. There is no need to perform a conversion operation, and the signal processing is efficient.

  Further, by arranging the four Hall elements as shown in FIG. 8, only by arranging the magnetic sensor unit 22 as one sensor package composed of the four Hall elements, the X direction and the Y direction can be obtained. The position where the position of the magnetic sensor unit 22 can be detected by simply installing one magnet 23 facing the magnetic sensor unit 22 can be detected. The detection mechanism 20 is realized. Thus, the arrangement of the Hall elements 2 a to 2 d shown in FIG. 8 is suitable for downsizing the position detection mechanism 20.

  In this embodiment, the magnetic sensor unit 22 includes four Hall elements, and a single magnetic sensor unit is configured to detect a change in the magnetic field in two directions, the X-axis direction and the Y-axis direction. An example is shown. However, one magnetic sensor unit may be provided in order to detect a magnetic field change in one direction. For example, one magnetic sensor unit that performs position detection in the X-axis direction is provided at a position outside the first actuator 123, and a position outside the second actuator 133 (installation of the position detection mechanism 20 shown in the above embodiment). One magnetic sensor unit for detecting the position in the Y-axis direction may be provided at the position). In this case, the corresponding components of the position detection devices 10A to 10C of the first to third embodiments can be adopted as the components of the position detection mechanism corresponding to each magnetic sensor unit.

  Further, in this embodiment, the case where the impact actuator using the piezoelectric element 82 as the driving means is applied to move the first and second sliders 13 and 14 as the moving members is illustrated. The present invention is not limited, and other driving means and driving methods may be adopted.

<6. Sixth Embodiment>
Next, a sixth embodiment of the present invention will be described. In the sixth embodiment, another specific usage form of the position detection device is illustrated. Here, a case will be described in which the position detection device is used for detecting the lens position of the imaging device.

  FIG. 16 is a diagram illustrating an imaging apparatus (here, a digital still camera) 300B.

  The imaging apparatus 300B includes a plurality of lenses 40, a camera body 60, a lens barrel 70, and the like. The imaging apparatus 300B has an autofocus function and a zoom function, and has a lens including a focus lens 40F and a zoom lens 40Z as the plurality of lenses 40. The focus lens 40F and the zoom lens 40Z can independently move relative to the lens barrel 70 in the optical axis direction.

  Further, the focus lens 40F and the zoom lens 40Z are provided with position detection devices 10F and 10Z for detecting the respective lens positions.

  Each of the position detection devices 10F and 10Z has the same configuration as that of the position detection device 10A of the first embodiment. For example, the position detection device 10F includes a magnet 1 and Hall elements 2a and 2b. Similarly, the position detection device 10Z includes a magnetic force generator (magnet) 1 and Hall elements 2a and 2b. Although not shown in FIG. 16, in order to process the outputs from the Hall element pairs of the position detection devices 10F and 10Z, the processing circuit 3 and the like similar to those of the first embodiment include the camera body 60. Is provided inside.

  The magnet 1 of the position detection device 10F is fixed to the bottom of the focus lens 40F that is a moving member, and the Hall elements 2a and 2b of the position detection device 10F are fixed to the inner surface of the lens barrel 70 that is a fixing member. ing. Therefore, the position detection device 10F can detect the relative position of the focus lens 40F with respect to the lens barrel 70 during focusing or the like. Then, the position of the focus lens 40F can be detected by the position detection device 10F, and the position of the focus lens 40F can be controlled using the detection result. For example, the position of the focus lens 40F can be made to follow the target position by feedback control or the like.

  Similarly, the magnet 1 of the position detection device 10Z is fixed to the bottom of the zoom lens 40Z that is a moving member, and the Hall elements 2a and 2b of the position detection device 10Z are fixed to the inner surface of the lens barrel 70 that is a fixing member. Has been. Therefore, the position detection device 10Z can detect the relative position of the zoom lens 40Z with respect to the lens barrel 70 during zooming or the like. Then, the position of the zoom lens 40Z can be detected by the position detection device 10Z, and the position of the zoom lens 40Z can be controlled using the detection result. For example, the position of the zoom lens 40Z can be made to follow the target position by feedback control or the like.

  According to the imaging apparatus 300B, it is possible to obtain the same advantages as those of the first embodiment. In addition, since the position detection device is a non-contact type, the position detection device does not have to be a noise generation source in the image pickup device, or the driving load is reduced, or dust associated with sliding or the like is not generated. You can also get the benefits. In the imaging apparatus 300B, a position detection device similar to that in the first embodiment is employed, but position detection devices similar to those in the second to fourth embodiments may be employed.

<7. Modification>
Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made.

  For example, as the magnetic force generator, other than a permanent magnet such as an electromagnet may be employed. Further, an MR element or the like may be employed as the magnetic sensor.

  In the first and third embodiments, the switching circuit 39 has the PNP type transistor 39t as the main configuration. However, the switching circuit 39 may have a P type FET as the main configuration.

  Moreover, although the imaging device of the said 5th and 6th embodiment was a digital still camera, the position detection apparatus which concerns on the said embodiment was added to the micro camera unit etc. as an imaging device contained in a mobile telephone apparatus etc. It may be adopted.

It is a perspective view which shows schematic structure of the position detection apparatus of 1st Embodiment. It is a figure which shows the electric constitution of the position detection apparatus of 1st Embodiment. It is a figure which shows the detection principle of the magnetism by a Hall element. It is a figure which shows the change of the level of an instruction | indication signal. It is a figure which shows the change of the level of an instruction | indication signal. It is a figure which shows the electric constitution of the position detection apparatus of 2nd Embodiment. It is a figure which shows the electrical structure of the position detection apparatus of 3rd Embodiment. It is a perspective view which shows schematic structure in the position detection apparatus of 4th Embodiment. It is a figure which shows the electrical constitution of the position detection apparatus of 4th Embodiment. It is a figure which shows the imaging device with which the position detection apparatus was integrated. It is an assembly exploded perspective view of a camera shake correction device. It is a principal part enlarged view at the time of seeing a magnet support part from the front. It is a figure which shows the structure of an impact actuator. It is sectional drawing which shows the II cross section of FIG. It is a block diagram which shows the electric constitution of the drive control circuit of a camera shake correction apparatus. It is a figure which shows another imaging device with which the position detection apparatus was integrated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnet 2 Sensor part 2a, 2b Hall element 3 Processing circuit 5 Microcomputer 34 Limiter part 37 Voltage adjustment circuit 39 Switching circuit

Claims (17)

A position detecting device,
A sensor unit for detecting magnetism from the magnetic force generator,
Position deriving means for deriving a relative position between the magnetic force generator and the sensor unit based on an output value from the sensor unit, and outputting a position signal indicating the relative position to an arithmetic circuit;
A sensor power supply that applies a voltage higher than the drive voltage of the arithmetic circuit to one power supply terminal of the sensor unit;
An adjustment circuit that adjusts an input value of the sensor unit in an active state and blocks a downstream circuit between the other power supply terminal of the sensor unit and a ground in an inactive state;
A switching circuit that shuts off an upstream circuit between the sensor power supply and the one power supply terminal of the sensor unit when the adjustment circuit is in an inactive state;
A position detection device comprising: The position detection device according to claim 1,
Instructing means for instructing transition between the active state and inactive state of the adjustment circuit, and instructing switching of connection / disconnection of the upstream circuit,
Further comprising
The position detecting device according to claim 1, wherein after the predetermined time elapses after the instruction to switch the upstream circuit from connection to disconnection, the instruction means instructs to shift the adjustment circuit from an active state to an inactive state. The position detection device according to claim 1,
Instructing means for instructing transition between the active state and inactive state of the adjustment circuit, and instructing switching of connection / disconnection of the upstream circuit,
Further comprising
The position detecting device according to claim 1, wherein after the predetermined time elapses after the instruction to shift the adjustment circuit from the inactive state to the active state, the instruction unit performs an instruction to switch the upstream circuit from shut-off to connection. The position detection device according to any one of claims 1 to 3,
The sensor part is composed of a pair of magnetic sensor pairs arranged apart from each other,
The position deriving means derives the relative position based on each output value from the pair of magnetic sensor pairs,
The adjustment circuit adjusts each voltage applied to the pair of magnetic sensor pairs in an active state, and sets a sum of magnitudes of output values from the pair of magnetic sensor pairs to a constant value. A position detection device. The position detection device according to claim 4,
When a combination of the pair of magnetic sensors, the position derivation means, and the adjustment circuit is a detection unit,
With multiple detection units,
An arrangement of the pair of magnetic sensor pairs included in each of the plurality of detection units is relatively fixed between the plurality of detection units. The position detection device according to claim 5,
One of the switching circuits is shared between the plurality of detection units. The position detection device according to any one of claims 1 to 3,
The sensor unit is composed of one magnetic sensor,
In the active state, the adjustment circuit adjusts a supply current to the magnetic sensor to be constant. A position detecting device,
A sensor unit for detecting magnetism from the magnetic force generator,
Position deriving means for deriving a relative position between the magnetic force generator and the sensor unit based on an output value from the sensor unit, and outputting a position signal indicating the relative position to an arithmetic circuit;
A sensor power supply that applies a voltage higher than the drive voltage of the arithmetic circuit to one power supply terminal of the sensor unit;
An adjustment circuit that adjusts an input value of the sensor unit in an active state and shuts off an upstream circuit between the sensor power source and the one power supply terminal of the sensor unit in an inactive state;
A position detection device comprising: The position detection device according to claim 1 or 8,
A limiter circuit for limiting the voltage of the position signal before being input to the arithmetic circuit to a predetermined range;
The position detection apparatus further comprising: The position detection device according to claim 9, wherein
An instruction means for instructing a transition between the active state and the inactive state of the limiter circuit, and an instruction to switch connection / disconnection of the upstream circuit;
Further comprising
The position detecting device according to claim 1, wherein after the predetermined time elapses after the instruction to switch the upstream circuit from connection to disconnection, the instruction means instructs the transition of the limiter circuit from an active state to an inactive state. The position detection device according to claim 9, wherein
An instruction means for instructing a transition between the active state and the inactive state of the limiter circuit, and an instruction to switch connection / disconnection of the upstream circuit;
Further comprising
The position detecting device according to claim 1, wherein after the predetermined time elapses after the limiter circuit is instructed to transition from the inactive state to the active state, the upstream circuit is switched from being disconnected to being connected. The position detection device according to any one of claims 8 to 11,
The sensor part is composed of a pair of magnetic sensor pairs arranged apart from each other,
The position deriving means derives the relative position based on each output value from the pair of magnetic sensor pairs,
The adjustment circuit adjusts each voltage applied to the pair of magnetic sensor pairs in an active state, and sets a sum of magnitudes of output values from the pair of magnetic sensor pairs to a constant value. A position detection device. The position detection device according to any one of claims 1 to 12,
The position detection device, wherein the arithmetic circuit is a microcomputer. A camera shake correction mechanism,
The position detection device according to any one of claims 1 to 13,
Detecting means for detecting a relative position of two objects that move relative to each other by using the position detecting device;
Drive means for correcting hand shake by performing relative driving of the two objects based on a detection result by the detection means;
A camera shake correction mechanism comprising: An imaging device,
The position detection device according to any one of claims 1 to 13,
Detecting means for detecting a relative position of two objects that move relative to each other by using the position detecting device;
Drive means for correcting hand shake by performing relative driving of the two objects based on a detection result by the detection means;
An imaging apparatus comprising: An imaging device,
An imaging optical system including a focus lens;
The position detection device according to any one of claims 1 to 13,
Lens position indicating means for detecting the position of the focus lens using the position detection device and controlling the position of the focus lens;
An imaging apparatus comprising: An imaging device,
An imaging optical system including a zoom lens;
The position detection device according to any one of claims 1 to 13,
Lens position indicating means for detecting the position of the zoom lens using the position detection device and controlling the position of the zoom lens;
An imaging apparatus comprising:

Images