JP2013117457A - Detector and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a necessary detection range with necessary resolution.SOLUTION: The detector detects a positional relationship between a first member and a second member moved relatively to the first member. The detector includes a first potentiometer for detecting a first range in the positional relationship, a second potentiometer for detecting a second range different from the first range in the positional relationship, and a generation part for combining outputs of the first potentiometer and the second potentiometer respectively to generate a detection output corresponding one to one to the positional relationship.

Description

  The present invention relates to a detection device and an optical device.

A technique for detecting the position of a throttle valve using a potentiometer is known (see, for example, Patent Document 1).
[Prior art documents]
[Patent Literature]
[Patent Document 1] Japanese Patent Publication No. 6-1184

  When one potentiometer is used, a necessary detection range may not be detected with a necessary resolution. When two potentiometers are used, complicated control may be required for the two potentiometers in order to detect with the required accuracy. In addition, complicated processing may be required for the results obtained by the two potentiometers.

  In the first aspect of the present invention, the detection device is a detection device that detects a positional relationship between a first member and a second member that moves relative to the first member. A first potentiometer that detects a first range of the relationship; a second potentiometer that detects a second range of the positional relationship different from the first range; and outputs of the first potentiometer and the second potentiometer And a generating unit that generates a detection output corresponding to the positional relationship on a one-to-one basis.

  In a second aspect of the present invention, an optical device includes the detection device and an optical lens having one or more movable lenses that move relative to a fixed barrel of the lens device, and the first potentiometer includes: The first range is detected in the positional relationship between the lens holding portion that holds the movable lens and the fixed barrel, and the second potentiometer detects the second range in the positional relationship.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

1 is a schematic cross-sectional view of a main part of an imaging device 100. FIG. 1 is a block diagram schematically showing a system configuration of an imaging apparatus 100. FIG. The position of each lens at the wide end is schematically shown. The position of each lens at the intermediate focal length is schematically shown. The position of each lens at the tele end is schematically shown. An example of the relationship between the rotation angle of the zoom ring 24 and the focal length is shown. A part of the position detection device 200 is schematically shown. A mode that the principal part of Drawing 5 was developed on a plane is shown typically. An example of a synthesis circuit for synthesizing detection signals is shown. An example of the output voltage of the operational amplifier 722 is shown. Another example of the output voltage of the operational amplifier 722 is shown. An example of a processing flow when the lens unit 20 is attached to the camera unit 30 is shown. An example of a processing flow when the imaging apparatus 100 is turned on is shown. The detailed processing flow of an imaging process is shown. An example of the processing flow when the user setting of shake correction is changed is shown. An example of the processing flow in reproduction mode is shown. Another example of the synthesis circuit for synthesizing the output of the potentiometer is shown. An example of the output voltage from the synthetic | combination circuit of FIG. 11 is shown. Another example of the synthesis circuit will be described. An example of the output voltage from the synthetic | combination circuit of FIG. 13 is shown. The other example of the resistor arrangement | positioning of a potentiometer is shown. An example of the output voltage obtained by the resistor arrangement illustrated in FIG. 15 is shown. Another arrangement example of the potentiometer is shown in a schematic cross-sectional view of the lens unit 20. An example of the resistor provided in the lens holding frame 12c is shown. The example which arrange | positions a resistor to a some lens holding frame is shown. Another example of the synthesis circuit will be described.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a schematic cross-sectional view of the main part of the imaging apparatus 100. The imaging device 100 includes a lens unit 20 and a camera unit 30.

  The lens unit 20 has a plurality of lenses L 1, L 2, L 3 and L 4 arranged along the optical axis 11. The plurality of lenses L1, L2, L3, and L4 constitute an imaging lens system. The lenses L1, L2, L3, and L4 may be a lens group including one or more lenses.

  The lens holding frames 12a, 12b, 12c, and 12d hold the lenses L1, L2, L3, and L4, respectively. The lens holding frame 12c that holds the lens L3 also holds the diaphragm 22. The lenses L1 to L4 are movably provided with respect to the fixed barrel 10. Specifically, the lenses L1 to L4 are movably provided in the direction of the optical axis 11 while being held by the lens holding frame 12.

  The lens L2 is a variable power lens mainly responsible for variable power. The lens unit 20 includes a zoom ring 24 that allows the user to perform an angle of view adjustment operation. When the user operates the zoom ring 24, the focal length of the lens system is adjusted. The lens L2 mainly responsible for zooming moves in the direction of the optical axis 11 when the zoom ring 24 is rotated around the optical axis 11. For example, the rotating cylinder 13 rotates around the optical axis 11 according to the rotation of the zoom ring 24, and the lens holding frame 12 b obtains a driving force that goes straight in the direction of the optical axis 11 according to the rotation of the rotating cylinder 13. The lens L2 is positioned at a position corresponding to the rotation angle of the zoom ring 24. Therefore, the rotation angle of the zoom ring 24 and the position of the lens L2 in the direction of the optical axis 11 have a corresponding relationship.

  In addition to the lens L2, the lenses L1, L3, and L4 also move in the direction of the optical axis 11 in accordance with the operation of the zoom ring 24. The lenses L1 to L4 move in the optical axis direction according to the operation of the zoom ring 24 so that the focus state does not change greatly even if the focal length is changed. The lens unit 20 includes a focus ring 25 on which a user manually performs a focus adjustment operation. When the focus ring 25 is operated, a lens that performs fine adjustment of the focus moves in the direction of the optical axis 11.

  The lenses L1 to L4 can move in the direction of the optical axis 11 in response to the driving force of the motor of the lens unit 20 as well as the operation of the zoom ring 24 and the focus ring 25. Any one of the lenses L1 to L4 may function as a blur correction lens that can be displaced with respect to the optical axis 11. For example, the lens L3 may function as a shake correction lens. The blur correction lens may be displaced so that at least one of the direction or position of the optical axis of the blur correction lens is different from the optical axis 11. For example, the blur correction lens may be displaced so as to have a vertical component on the optical axis 11. Further, the shake correction lens may be displaced with respect to the optical axis 11 by tilting. The displacement of the blur correction lens may be displaced by a driving force such as a motor. The lens system control unit 23 as a part of the lens control system controls and calculates the lens unit 20 such as control of lens driving force by a motor or the like. In the description of the present embodiment, the z-axis is determined in the direction in which the subject luminous flux travels along the optical axis 11.

  The lens unit 20 includes a lens mount 26 at a connection portion with the camera unit 30, engages with a camera mount 48 included in the camera unit 30, and is integrated with the camera unit 30. Each of the lens mount 26 and the camera mount 48 includes an electrical connection portion in addition to a mechanical engagement portion, and realizes power supply from the camera unit 30 to the lens unit 20 and mutual communication.

  The camera unit 30 includes a main mirror 31 that reflects the subject light beam incident from the lens unit 20 and a focus plate 33 on which the subject light beam reflected by the main mirror 31 forms an image. The main mirror 31 can take a state of being obliquely provided in the subject light flux centered on the optical axis 11 and a state of being retracted from the subject light flux. In this figure, the state of being obliquely set is indicated by a solid line, and the state of being retracted from the subject light beam is indicated by a dotted line. When the subject light flux is guided to the focus plate 33 side, the main mirror 31 is provided obliquely in the subject light flux. The focus plate 33 is disposed at a position conjugate with a light receiving surface of an image sensor 42 described later.

  The subject image formed on the focus plate 33 is converted into an erect image by the pentaprism 34, passes through the half mirror 92, and is presented to the user via the finder optical system 35 and the finder 90. An AE sensor 36 is disposed above the exit surface of the pentaprism 34 to detect the illuminance distribution of the subject image.

  The half mirror 92 superimposes the image formed on the finder display unit 94 and passing through the lens 95 on the subject image on the focus plate 33. As a result, the subject image on the focus plate 33 and the image on the finder display unit 94 can be seen together at the exit end of the finder optical system 35. The finder display unit 94 displays information such as imaging conditions and setting conditions of the imaging device 100, for example.

  The region near the optical axis 11 of the main mirror 31 in the oblique state is formed as a half mirror, and a part of the incident light beam is transmitted. The transmitted light beam is reflected by the sub mirror 37 operating in conjunction with the main mirror 31 and guided to the AF unit 39. The AF unit 39 detects a phase difference signal from the subject light flux. The sub mirror 37 retracts from the subject light beam in conjunction with the main mirror 31 when the main mirror 31 retracts from the subject light beam.

  A focal plane shutter 40, an optical low-pass filter 41, and an image sensor 42 are arrayed along the optical axis 11 behind the oblique main mirror 31. The focal plane shutter 40 is in an open state when the subject light flux is guided to the image sensor 42 and is in a shielded state at other times. The optical low-pass filter 41 plays a role of adjusting the spatial frequency of the subject image with respect to the pixel pitch of the image sensor 42. The image sensor 42 is formed by a plurality of photoelectric conversion elements. The image sensor 42 may be a CCD, a CMOS sensor, or the like. The image sensor 42 converts the subject image formed on the light receiving surface into an electric signal.

  The electrical signal photoelectrically converted by the image sensor 42 is converted into image data by the camera processing unit 55. The camera processing unit 55 manages various operation sequences of the camera and performs input / output processing of each component. For example, the exposure value is calculated from the illuminance distribution of the subject image output from the AE sensor 36, and focus control is performed from the phase difference signal output from the AF unit 39.

  The display unit 46 displays information such as the subject image processed by the image processing unit in the camera processing unit 55, imaging conditions, and setting conditions. The display unit 46 may be a liquid crystal monitor or the like. The display unit 46 displays not only the captured image but also an image as a viewfinder, various menu information, imaging conditions, setting conditions, and the like. The camera unit 30 houses a detachable secondary battery 47, and supplies power to the lens unit 20 as well as the camera unit 30.

  FIG. 2 is a block diagram schematically showing the system configuration of the imaging apparatus 100. The system of the imaging apparatus 100 includes a lens control system centered on the lens system control unit 23 and a camera control system centered on the camera system control unit 44 corresponding to each of the lens unit 20 and the camera unit 30. The The lens control system and the camera control system exchange various data and control signals with each other via a connection portion connected by the lens mount 26 and the camera mount 48.

  The camera processing unit 55 belongs to the camera control system. The image processing unit 45 included in the camera processing unit 55 processes the imaging signal photoelectrically converted by the imaging element 42 in accordance with a command from the camera system control unit 44 to generate image data. The generated display image data is sent to the display unit 46. The display unit 46 displays image data for display for a certain time after imaging, for example. In parallel, the processed image data is processed into a predetermined image format and recorded in the memory 51 as captured image data. Display image data continuously generated every time an image is captured is sequentially displayed on the display unit 46 without being recorded in the memory 51. As a result, the user can not only optically observe the subject image via the finder optical system 35 but also visually recognize the subject image via the display unit 46.

  A camera operation detection unit 50 included in the camera processing unit 55 detects an operation from a user. The camera system control unit 44 performs an operation corresponding to the operation from the user detected by the camera operation detection unit 50. For example, the camera system control unit 44 performs an operation corresponding to the operation input from the operation input unit 49.

  As a part of the operation input unit 49, a release button having a two-stage switch position in the pushing direction may be included. When the camera operation detection unit 50 detects that the release button is operated by the user and the first-stage switch is turned on, the camera system control unit 44 acquires a phase difference signal from the AF unit 39. And the camera system control part 44 transmits the drive information for driving the lens which takes a focus to the lens system control part 23 which belongs to a lens control system. Further, the camera system control unit 44 acquires the illuminance distribution of the subject image from the AE sensor 36 and determines the exposure value. Further, the camera system control unit 44 transmits drive information for driving the lens responsible for zooming to the lens system control unit 23 when the camera operation detection unit detects an operation for adjusting the angle of view. Further, when the camera operation detection unit 50 detects that the second-stage switch is turned on, the camera system control unit 44 executes a series of imaging sequences to generate captured image data and records it in the memory 51. .

  The lens system control unit 23 receives various control signals from the camera system control unit 44 and executes various operations. When the lens system control unit 23 receives lens drive information from the camera system control unit 44, the lens system control unit 23 calculates the movement amount of the lens and controls the drive driver 150 to move the lens by the calculated movement amount. Position information regarding the position of the lens is detected by the position detection device 200. The lens system control unit 23 calculates a focal length based on the detected position information, and transmits the calculated focal length to the camera system control unit 44.

  When the user moves the rotary cylinder 13 with a driving force for rotating the zoom ring 24, the position information is sequentially detected by the position detection device 200. The lens system control unit 23 calculates a focal length based on the detected position information, and transmits the calculated focal length to the camera system control unit 44. The lens system control unit 23 may sequentially transmit the focal length to the camera system control unit 44. The lens system control unit 23 functions as a control unit that controls the amount of displacement of the blur correction lens with respect to the optical axis 11 based on the detection output from the position detection device 200. Specifically, the lens system control unit 23 controls the amount of displacement of the blur correction lens based on the calculated focal length.

  FIG. 3A schematically shows the position of each lens at the wide end. FIG. 3B schematically shows the position of each lens at the intermediate focal length. FIG. 3C schematically shows the position of each lens at the telephoto end. 3A to 3C show a fixed barrel 10 as an example of a fixed member, and lenses L1 to L4 that move relative to the fixed barrel 10. The focal length is determined by the positional relationship of the lenses L1 to L4, particularly the positional relationship of the lenses that are responsible for zooming.

  As the zoom ring 24 rotates relative to the fixed barrel 10 around the optical axis 11, the positional relationship between the lenses L1 to L4 changes. In this description, the relative rotation angle of the zoom ring 24 with respect to the fixed barrel 10 is simply referred to as a rotation angle. The driving mechanisms for the lenses L1 to L4 are set so that the rotation angle and the focal length correspond one-to-one. That is, it continuously changes from the tele end to the wide end in accordance with the continuous change in the rotation angle. That is, the positional relationship between the lenses L1 to L4 and the fixed barrel 10 is determined corresponding to the rotation angle. Therefore, the focal length of the lens system is also determined according to the rotation angle. The position detection device 200 detects a rotation angle as an example of a positional relationship, for the purpose of calculating a focal length.

  FIG. 4 shows an example of the relationship between the rotation angle of the zoom ring 24 and the focal length. As illustrated in this figure, the rate of change of the focal length per rotation angle increases as the focal length increases. That is, when the zoom ring 24 is rotated by a certain angle, the focal length changes more greatly on the tele side than on the wide side. Therefore, in order to detect the focal length with high accuracy, it is necessary to detect the rotation angle with high resolution at least on the telephoto side.

  Further, the blurring at the time of image capturing by the image capturing apparatus 100 greatly affects the image blur as the focal length increases. Therefore, it may be preferable to determine whether or not it is necessary to perform blur correction based on the focal length. It may be preferable to adjust the degree of blur correction based on the focal length.

  Therefore, the position detection device 200 detects the rotation angle with a different resolution for each range of the focal length for the purpose of detecting the focal length with necessary accuracy. Further, the position detection device 200 detects the rotation angle without driving the lens for the purpose of quickly detecting the focal length.

  FIG. 5 schematically shows a part of the position detection device 200. The fixed member 500 is a member fixed to the fixed barrel 10. The fixing member 500 may be a part of the fixed barrel 10. The rotating member 530 rotates around the optical axis 11 according to the rotation of the zoom ring 24. The rotating member 530 may be a part of the rotating cylinder 13.

  A first potentiometer 510 as a part of the position detection device 200 includes a resistor 511, a conductor 512, and a brush 515. The resistor 511 and the conductor 512 are continuously formed on the rotating member 530. One end of the input of the first potentiometer 510 is grounded, and a voltage is applied to the other end of the input. For example, one end on the resistor 511 side is grounded, and a voltage is applied to one end on the conductor 512 side.

  The electrical resistance per unit length of the conductor 512 is higher than that of the resistor 511. The length here is the length in the circumferential direction around the optical axis 11. Specifically, the conductor 512 is formed using a conductive material having an electrical resistivity lower than that of the resistor 511. For example, it is made of a conductive material such as graphite or gold. And let the resistor 511 and the conductor 512 have the same area of the cross section cut | disconnected by radial direction. Specifically, it is assumed that the resistor 511 and the conductor 512 have the same width as the length in the direction of the optical axis 11 and the height as the length in the radial direction.

  The second potentiometer 520 as a part of the position detection device 200 is provided separately from the first potentiometer 510. Second potentiometer 520 includes a resistor 521, a conductor 522, and a brush 525. The resistor 511 and the conductor 512 are continuously formed on the rotating member 530. The resistor 521 is provided in a range not corresponding to the range in which the resistor 511 is formed so that the second potentiometer 520 detects a range of a focal length different from that of the first potentiometer. Except for this difference, the first potentiometer 510 and the second potentiometer 520 have a corresponding configuration.

  That is, like the first potentiometer 510, one end of the input of the second potentiometer 520 is grounded, and a voltage is applied to the other end of the input. For example, one end on the conductor 512 side is grounded, and a voltage is applied to one end of the resistor 511.

  Similar to the first potentiometer 510, in the second potentiometer 520, the electrical resistance per unit length of the conductor 522 is smaller than that of the resistor 521. Specifically, the conductor 522 is formed using a conductive material having an electrical resistivity lower than that of the resistor 521. Further, it is assumed that the resistor 521 and the conductor 522 have the same cross-sectional area. Specifically, it is assumed that the resistor 521 and the conductor 522 have the same width and the same height.

  The resistor 511 and the resistor 521 may be formed of the same material. Further, the conductor 512 and the conductor 522 may be formed of the same material.

  When the rotating member 530 rotates relative to the fixed member 500, the first brush 515 slides on the resistor 511 or the conductor 512. The second brush 525 slides on the resistor 521 or the conductor 522.

  The resistor 511 is provided in a range in contact with the first brush 515 when the focal length is in the first range. On the other hand, the conductor 512 is provided in a range in contact with the first brush 515 when the focal length is in a second range different from the first range. The partial pressure value at the sliding contact position of the first brush 515 is the output of the first potentiometer 510. When the first brush 515 is in sliding contact with the resistor 511, a substantially different partial pressure value is obtained depending on the position on the resistor 511. However, when the first brush 515 is in sliding contact with the conductor 512, it is impossible to detect in which position on the conductor 512 the first brush 515 exists. Accordingly, the first potentiometer 510 can substantially detect the first range of the focal length.

  When the focal length is in the first range, the conductor 522 is provided in a range in contact with the second brush 525. On the other hand, the resistor 521 is provided in a range in contact with the second brush 525 when the focal length is in the second range. The partial pressure value at the sliding contact position of the second brush 525 is the output of the second potentiometer 520. When the second brush 525 is in sliding contact with the resistor 521, a substantially different partial pressure value is obtained depending on the position on the resistor 521. However, when the second brush 525 is in sliding contact with the conductor 522, it is substantially impossible to detect where the second brush 525 exists on the conductor 522. Therefore, the second potentiometer 520 can substantially detect the second range of the focal length.

  FIG. 6 schematically shows a state in which the main part of FIG. The direction indicated by θ in the figure corresponds to the angle around the optical axis 11. One end T1 of the resistor 511 corresponds to the sliding contact position with the first brush 515 at the tele end. One end T2 of the resistor 521 corresponds to the sliding contact position with the second brush 515 at the tele end. One end T1 of the resistor 511 and one end T2 of the resistor 521 are grounded.

  One end W1 of the conductor 512 corresponds to a sliding contact position with the first brush 515 at the wide end. One end W2 of the conductor 522 corresponds to the sliding contact position with the second brush 525 at the wide end. A voltage V1 is applied to one end W1 of the conductor 512. A voltage V2 is applied to one end W2 of the conductor 522.

  Therefore, when the telephoto end changes toward the wide end, the sliding contact position with the first brush 515 is more than the boundary position with the conductor 512 while the focal length is in the first range from the focal length at the telephoto end. Located on the resistor 511 side. Therefore, the output voltage from the first brush 515 changes monotonously from 0 to V1. When the focal length is in the second range, the sliding contact position with the first brush 515 is closer to the conductor 512 than the boundary position. Therefore, the output voltage from the first brush 515 does not substantially change and takes a constant value V1.

  On the other hand, in the second potentiometer 520, while the focal length is in the first range from the telephoto end, the sliding contact position with the second brush 525 is closer to the conductor 522 than the boundary position with the resistor 521. Therefore, the output voltage from the second brush 525 takes a constant value 0 while the focal length is in the first range. While the focal length is in the second range, the sliding contact position with the second brush 525 is closer to the resistor 521 than the boundary position. Therefore, while the focal length is in the second range, the output voltage of the second brush 525 changes monotonically from 0 to V1.

  Note that the resistor 511 may be provided on either the fixed member 500 or the rotating member 530. That is, the resistor 511 may be fixed to one member of the fixed member 500 and the rotating member 530, and a voltage may be applied to both ends. The first brush 515 slides on the resistor 511 according to the relative movement amount when the other member of the fixed member 500 and the rotating member 530 moves relative to the one member. What is necessary is just to provide. Similarly, the resistor 521 may be fixed to one member of the fixing member 500 and the rotating member 530, and a voltage may be applied to both ends. The second brush 525 slides on the resistor 521 according to the relative movement amount when the other member of the fixed member 500 and the rotating member 530 moves relative to the one member. What is necessary is just to provide. The first resistor 511 is provided at a position in sliding contact with the first brush 515 when the rotation angle is in the first range, and the resistor 521 is connected to the second brush 525 when the rotation angle is in the second range. What is necessary is just to be provided at least in the position which contacts.

  As described above, the first brush 515 and the second brush 525 slide on the resistor corresponding to each brush by a distance corresponding to the amount of movement according to the rotation angle. The length in which the resistor 511 is in sliding contact with the first brush 515 is shorter than the length in which the resistor 521 is in sliding contact with the second brush 525. For this reason, the detection sensitivity of the first potentiometer 510 in the first range is higher than the detection sensitivity of the second potentiometer 520 in the second range. Note that the difference in detection sensitivity may be adjusted by the magnitude of the applied voltage.

  FIG. 7 shows an example of a combining circuit that combines the detection signals. The synthesis circuit includes an adder circuit 710 and an inverting amplifier circuit 720. In this figure, V1 = V2 = V0. In this figure, the resistor 511 of the first potentiometer 510 is schematically shown as r1. Further, the resistor 521 of the second potentiometer 520 is schematically shown as r2.

  The analog output voltage from the first brush 515 is input to the inverting input terminal of the operational amplifier 712 via the resistor R1. The analog output voltage from the second brush 525 is input to the inverting input terminal of the operational amplifier 712 via the resistor R2. The non-inverting input terminal of the operational amplifier 712 is grounded. The output of the operational amplifier 712 is fed back to the non-inverting input terminal via the resistor R3. When the output voltages of the first potentiometer 510 and the second potentiometer 520 are v1 and v2, respectively, the output voltage of the operational amplifier 712 is −R3 (v1 / R1 + v2 / R2).

  The output voltage of the operational amplifier 712 is input to the inverting input terminal of the operational amplifier 722 via R4. The non-inverting input terminal of the operational amplifier 722 is grounded. The output of the operational amplifier 722 is fed back to the non-inverting input terminal via the resistor R5. Therefore, the output voltage of the operational amplifier 722 is R3 × R5 × (v1 / R1 + v2 / R2) / R4.

  The synthesizing circuit of this example generates an analog detection output corresponding to the rotation angle on a one-to-one basis by adding the analog output from the first potentiometer 510 and the analog output from the second potentiometer 520. Can do. More specifically, the adder circuit 710 adds the voltage output from the first potentiometer 510 and the voltage output from the second potentiometer 520 to generate a voltage output corresponding to the rotation angle and one-to-one. Functions as a generation unit.

  FIG. 8 shows an example of the output voltage of the operational amplifier 722. This figure is an example of an output voltage when V0 = 5 V, R1 = 5 kΩ, R2 = 1.25 kΩ, R3 = 1 kΩ, R4 = 10 kΩ, and R5 = 10 kΩ.

  The output voltage 810 of the first potentiometer 510 takes a value from 0 V to 5 V in proportion to the rotation angle in the first range of the rotation angle from the tele end state to the angle θ1. In the second range larger than the angle θ1, the output voltage 810 has a constant value of 5V. The output voltage 820 of the second potentiometer 520 is a constant value 0V in the first range. In the second range, the output voltage 820 increases from 0V to 5V in proportion to the rotation angle.

  In this example, for simplicity, θ1 = θmax / 5. That is, the first potentiometer 510 that detects the first range has a sensitivity that is four times the sensitivity of the second potentiometer 520 that detects the second range. For this reason, the rotation angle can be detected with high accuracy on the tele side. That is, by making the length of the resistor 511 shorter than the length of the resistor 521, the rotation angle can be detected with high sensitivity on the telephoto side. On the other hand, as illustrated in FIG. 4, on the wide side, the dependence of the focal length on the rotation angle is relatively small. For this reason, when the objective is to detect the focal length, sufficient detection accuracy can be obtained even if the resolution on the wide side is somewhat low.

  Further, as in this example, in the addition circuit 710, the amplification factor (R3 / R2) for the output voltage from the second potentiometer 520 is set to four times the amplification factor (R3 / R1) for the first potentiometer 510. As a result, an output voltage proportional to the rotation angle can be generated. Thereby, the lens system control part 23 can calculate a rotation angle directly from the output voltage of the position detection apparatus 200, without referring to a conversion table according to an output voltage. Thus, the adding circuit 710 amplifies and adds the voltage output from the first potentiometer 510 having the lower detection sensitivity with an amplification factor higher than the amplification factor for the voltage output from the other second potentiometer 520. For this reason, linearity can be provided between the rotation angle and the analog output. The amplification factor here may be a value larger than zero. For example, the amplification factor may be less than 1.

  As described above, by adding the output voltages of the first potentiometer 510 and the second potentiometer 520 by the adder circuit 710, it is possible to obtain the output voltage 800 that changes monotonically over the first range and the second range. That is, the output voltage 800 corresponding to the rotation angle can be obtained over the entire range of the rotation angle to be detected. Since the rotation angle and the focal distance correspond one-to-one, the position detection device 200 can generate an output voltage corresponding to the focal distance one-to-one. Thereby, the lens system control part 23 can convert the output voltage of the position detection apparatus 200 into a focal distance by a comparatively simple calculation.

  Further, according to the position detection device 200, the absolute value of the rotation angle can be detected from the output voltage. Therefore, the focal length can be detected without driving the lens and changing the position of the lens in the direction of the optical axis 11.

  As described above, the first potentiometer 510 can detect the first range of the rotation angles. And the 2nd potentiometer 520 can detect the 2nd range different from the 1st range among rotation angles. The combining circuit functions as a generating unit that combines the outputs of the first potentiometer 510 and the second potentiometer 520 to generate a detection output corresponding to the rotation angle on a one-to-one basis. The rotation angle in this example indicates a positional relationship between a fixed barrel 10 as an example of a first member and a lens holding frame 12 as an example of a second member that moves relative to the fixed barrel 10. . Therefore, according to the position detection device 200, the entire range of the positional relationship can be divided into a plurality of parts, and each range can be detected by the corresponding potentiometer. For this reason, each range of the positional relationship can be detected with a desirable resolution.

  FIG. 9 shows another example of the output voltage of the operational amplifier 722. This example shows the output voltage when the synthesis circuit corresponding to the example of FIG. 7 is applied except that R1 = 1.25 kΩ and R2 = 5 kΩ. The output voltage 900 of the operational amplifier 722 varies between 0V and 4V in the first range of rotation angles. On the other hand, it varies between 4V and 5V in the second range of the rotation angle. That is, in the output range of 5V width of the operational amplifier 722, a range (4V) wider than the range (1V) assigned to the second range can be assigned to the first range of the rotation angle. Therefore, according to this example, when the output voltage of the operational amplifier 722 is converted into a discrete value by the AD converter, more bits can be assigned to the first range of the rotation angle.

  FIG. 10A shows an example of a processing flow when the lens unit 20 is attached to the camera unit 30. This processing flow is started when the camera system control unit 44 detects that the position detection device 200 is mounted. For example, the processing is started when the camera system control unit 44 detects that the lens mount 26 is mechanically engaged with the camera mount 48.

  In step S <b> 1002, the camera system control unit 44 starts power feeding to the lens unit 20. When power is supplied to the lens unit 20, a voltage is applied to both input terminals of the first potentiometer 510 and the second potentiometer 520, and a voltage value indicating the rotation angle is output from the synthesis circuit. In this step, the lens system control unit 23 does not need to supply power to a lens driving system such as a driving driver.

  In step S1004, the lens system control unit 23 AD converts the voltage value from the synthesis circuit into a digital value, and calculates a focal length based on the digital value. For example, the lens system control unit 23 may convert the digital value into the focal length with reference to a table in which the correspondence relationship between the rotation angle and the focal length is recorded in advance.

  In step S <b> 1006, the camera system control unit 44 acquires lens specific information and a focal length from the lens system control unit 23. In step S1008, the camera system control unit 44 displays the lens information and the focal length on the display unit 46. When the display on the display unit 46 is completed, this processing flow ends. According to this processing flow, when the user wears the lens unit 20, information on the worn lens unit 20 can be presented to the user. In addition, the current focal length can be quickly calculated and presented to the user without supplying power to a lens driving system such as a driving driver, and thus without driving the variable power lens.

  FIG. 10B shows an example of a processing flow when the power of the imaging apparatus 100 is turned on. This processing flow is started when the operation input unit 49 is turned on with the lens unit 20 mounted on the camera unit 30.

  In step S1012, power supply to the camera unit 30 and the lens unit 20 is started. As described with reference to step S1002 in FIG. 10A, when power is supplied to the lens unit 20, a voltage value indicating the rotation angle is output from the synthesis circuit. In this step, the lens system control unit 23 does not need to supply power to a lens driving system such as a driving driver.

  In step S1014, the lens system control unit 23 calculates a focal length. The lens system control unit 23 calculates the focal length by the operation described in relation to step S1004 in FIG. 10A.

  In step S1016, the camera system control unit 44 determines the operation mode. The operation mode may be determined according to an operation of turning on the power. For example, when an operation of pressing a release button as a part of the operation input unit 49 is performed as a power-on operation, an imaging mode for performing an operation mainly for imaging is set. On the other hand, when an operation for the image playback button as a part of the operation input unit 49 is performed as a power-on operation, a playback mode for performing an operation mainly for the purpose of image playback is set.

  When the imaging mode is set, in step S1018, the camera system control unit 44 acquires lens specific information and a focal length. In step S <b> 1020, the camera system control unit 44 performs an exposure calculation based on the output of the AE sensor 36. The camera system control unit 44 calculates, for example, the exposure time by this calculation.

  In step S1022, the camera system control unit 44 determines whether blur correction should be performed. For example, if the exposure time calculated in step S1020 is longer than the reciprocal of the focal length, it is determined that blur correction should be performed. If it is determined that the shake correction is to be performed, the display unit 46 displays that the shake correction is to be performed in step S1024. For example, if the user setting for blur correction is set to always OFF for not performing blur correction, a message indicating that blur correction is recommended is displayed. Further, when AUTO for automatically determining ON / OFF of the shake correction is set as the shake correction user setting, a message indicating that the shake correction is to be operated is displayed.

  If it is determined in step S1022 that no blur correction is to be performed, in step S1026, a message indicating that blur correction is not performed is displayed. For example, when AUTO is set as the user setting for shake correction, a message indicating that the shake correction is not operated is displayed.

  Following the processing in steps S1024 and S1026, imaging processing is performed in step S1028. The flow of the main imaging process will be described with reference to FIG. 10C. If the playback mode is set in step S1016, playback processing is performed in step S1030. The flow of this reproduction process will be described with reference to FIG. 10E. When the processes of step S1028 and step S1030 are completed, this process flow ends.

  FIG. 10C shows a detailed processing flow of the imaging process. In step S1032, the camera system control unit 44 receives a user setting for shake correction. For example, a change in blur correction setting is received from the user. For example, a user setting switch operation as a part of the operation input unit 49 is accepted.

  Subsequently, in step S1034, the camera system control unit 44 determines whether or not to perform blur correction. For example, if it is determined in step S1022 in FIG. 10B that blur correction is to be performed and the user setting for blur correction is set to AUTO, it is determined that blur correction is to be performed. In addition, when the user setting of the blur correction is set to always ON for performing the blur correction, it is determined that the blur correction is to be performed.

  In step S1036, the lens system control unit 23 sets a control parameter for controlling the drive driver 150. Specifically, the camera system control unit 44 instructs the lens system control unit 23 to perform blur correction. The lens system control unit 23 sets a control parameter based on the focal length. For example, the lens system control unit 23 sets a control parameter for setting a displacement amount of the blur correction lens with respect to the optical axis 11 based on the focal length. Specifically, a control parameter for displacing the blur correction lens is set larger as the focal length is shorter. In step S <b> 1038, the lens system control unit 23 drives the drive driver 150 based on the control parameter to start a shake correction operation.

  In step S1040, the camera system control unit 44 and the lens system control unit 23 cooperate to start focus adjustment based on the detection output of the AF unit 39. Thereafter, the focus adjustment by the AF unit 39 continues until a photographing instruction is received. In step S1042, it is determined whether the release button is pressed. When the first-stage switch of the release button is turned on, the focus area is set in step S1044, and the process returns to the determination in step S1042. When the second-stage switch of the release button as an example of the shooting instruction is turned on, in step S1046, the camera system control unit 44 raises the main mirror 31 so that it is retracted from the subject luminous flux.

  In step S1048, the image sensor 42 starts exposure under the control of the camera system control unit 44. When the exposure is completed, in step S1050, the main mirror 31 is lowered to a state where it is obliquely provided in the subject light beam. In step S <b> 1052, the captured image data generated by the image processing unit 45 is recorded in the memory 51. At this time, the lens information including the focal length may be recorded in association with the incidental information of the captured image data. When the recording of the captured image data is completed, this process ends.

  In this flow, the operation when the user operates the release button has been described in the processing after step S1034 for the purpose of easily explaining the flow of the imaging processing. However, for example, when the user rotates the zoom ring 24 in the processing after step S 1034, the lens system control unit 23 calculates the focal length based on the output from the position detection device 200 and transmits it to the camera system control unit 44. May be. Based on the focal length value received from the lens system control unit 23, the camera system control unit 44 determines whether or not to perform blur correction, and determines that the blur correction is to be performed. Based on this, a control parameter for controlling the drive driver 150 may be set.

  FIG. 10D shows an example of a processing flow when the user setting for shake correction is changed. This processing flow is started when the shake correction user setting is changed by, for example, a user setting switch operation.

  In step S1062, the lens system control unit 23 calculates a focal length. The lens system control unit 23 calculates the focal length by the operation described in relation to step S1004 in FIG. 10A. The focal length calculated by the lens system control unit 23 is acquired by the camera system control unit 44.

  In step S <b> 1064, the camera system control unit 44 performs an exposure calculation based on the output of the AE sensor 36. The camera system control unit 44 calculates, for example, the exposure time by this calculation.

  In step S <b> 1066, the camera system control unit 44 determines whether blur correction should be performed. Specifically, it is determined whether blur correction should be performed by the same process as in step S1022 of FIG. 10B. If it is determined in step S1066 that blur correction should be performed, in step S1068, the fact that blur correction should be performed is displayed on the display unit 46. For example, when this processing flow is started by changing the setting of blur correction to always OFF, a message indicating that blur correction is recommended is displayed. In addition, when this processing flow is started by changing the setting of the blur correction to AUTO, a message indicating that the blur correction is to be operated is displayed.

  If it is determined in step S1068 that no blur correction is to be performed, in step S1070, a message indicating that no blur correction is to be performed is displayed. For example, when the processing flow is started by changing the setting of blur correction to AUTO, a message indicating that the blur correction is not operated is displayed. When the processes of step S1068 and step S1070 are completed, the process flow ends. According to this processing flow, when the user setting for blur correction is changed, it is possible to quickly determine whether the blur correction setting is suitable for the imaging environment. For example, the determination can be made without supplying power to a lens driving system such as a driving driver, and thus without driving the variable magnification lens.

  FIG. 10E shows an example of the processing flow in the playback mode. This processing flow can be applied to the detailed processing flow related to step S1030 in FIG. 10B. Here, a processing flow when a shooting instruction is accepted during the reproduction operation is illustrated. This processing flow is started on the condition that the second-stage switch of the release button is turned on when the image capturing apparatus 100 is mainly performing image data reproduction operation in the reproduction mode.

  In step S1082, power supply to the lens unit 20 is started. As described with reference to step S1002 in FIG. 10A, when power is supplied to the lens unit 20, a voltage value indicating the rotation angle is output from the synthesis circuit. In this step, the lens system control unit 23 does not need to supply power to a lens driving system such as a driving driver.

  In step S1084, the lens system control unit 23 calculates a focal length. The lens system control unit 23 calculates the focal length by the operation described in relation to step S1004 in FIG. 10A.

  In step S1086, the system control unit 250 acquires lens specific information and a focal length. In step S <b> 1088, the camera system control unit 44 performs an exposure calculation based on the output of the AE sensor 36. The camera system control unit 44 calculates, for example, the exposure time by this calculation.

  In step S1090, an image stabilization operation and related display are performed. In this step, the processing described in relation to step S1022, step S1024, and step S1026 in FIG. 10B is performed. When these processes are completed, an imaging process is performed in step S1092. In this step, the processing described in relation to FIG. 10C is performed. When the process of step S1092 is completed, the process flow ends.

  According to this processing flow, when the release button is pressed during image reproduction, the focal length is promptly supplied without supplying power to the lens drive system such as the drive driver, and thus without driving the zoom lens. Can be calculated and a transition can be made quickly to the imaging operation.

  FIG. 11 shows another example of the synthesis circuit that synthesizes the output of the potentiometer. In this example, one end of the input of the first potentiometer 510 is set to the ground potential, and the voltage V1 is supplied to the other end. On the other hand, the output potential of the first potentiometer 510 is supplied to the potential at one end of the input of the second potentiometer 520, and the voltage V2 is supplied to the other end. V1 may be positive or negative. When V1 is a positive value, V2> V1. When V1 is a negative value, V2 <V1.

  The output voltage from the first potentiometer 510 is input to the non-inverting input terminal of the operational amplifier 1110. The output from the operational amplifier 1110 is fed back to the inverting input terminal of the operational amplifier 1110. That is, the operational amplifier 1110 operates as a voltage follower. The output potential of the operational amplifier 1110 is provided as an input potential at one end of the second potentiometer 520. Specifically, the output terminal of the operational amplifier 1110 is electrically connected to one end of the input of the second potentiometer 520.

  The output voltage from the second potentiometer 520 is input to the non-inverting input terminal of the operational amplifier 1120. The output from the operational amplifier 1120 is fed back to the inverting input terminal of the operational amplifier 1120. That is, the operational amplifier 1120 operates as a voltage follower. Then, the output voltage from the operational amplifier 1120 becomes the output from the position detection device 200.

  FIG. 12 shows an example of the output voltage from the synthesis circuit of FIG. This example shows an example of the output voltage when V1 = 3V and V2 = 6V. In the first range of the rotation angle, the output voltage 1210 of the operational amplifier 1110 takes a value from 0V to V1. That is, it takes a value from 0 to 3V. On the other hand, in the second range of the rotation angle, the output voltage 1210 takes a constant value of 3V.

  In the first range of rotation angles, the output voltage 1200 from the operational amplifier 1120 matches the output voltage 1210 of the operational amplifier 1110. In the second range of the rotation angle, the output voltage from the operational amplifier 1120 changes according to the change in the output voltage from the second potentiometer 520. Specifically, the output voltage from the position detection device 200 is as shown by the output voltage 1200 in the figure.

  Also with the synthesis circuit of this example, it is possible to obtain the output voltage 1200 corresponding to the rotation angle on a one-to-one basis. That is, the output voltage 1200 corresponding to the focal length can be obtained.

  FIG. 13 shows still another example of the synthesis circuit. The synthesis circuit of this example is different from the synthesis circuit illustrated in FIG. 11 in that the output voltage of the first potentiometer 510 is reduced and input to one end of the second potentiometer 520.

  That is, the output voltage of the first potentiometer 510 is input to the non-inverting input terminal of the operational amplifier 1310. The output of the operational amplifier 1310 is fed back to the inverting input terminal of the operational amplifier 1310. That is, the operational amplifier 1310 operates as a voltage follower.

  The attenuation circuit 1312 attenuates the output voltage from the operational amplifier 1310 and provides the obtained potential as an input potential at one end of the input of the second potentiometer 520. Specifically, the output terminal of the attenuation circuit 1312 is electrically connected to one end of the second potentiometer 520.

  The output voltage of the second potentiometer 520 is input to the non-inverting input terminal of the operational amplifier 1320. The output of the operational amplifier 1320 is fed back to the inverting input terminal of the operational amplifier 1320. That is, the operational amplifier 1320 operates as a voltage follower. Then, the output voltage from the operational amplifier 1320 becomes the output from the position detection device 200.

  FIG. 14 shows an example of the output voltage from the synthesis circuit of FIG. This example shows an output voltage when V1 = V2 = 5V and the attenuation rate by the attenuation circuit 1312 is ½. In the first range of the rotation angle, the output voltage 1410 of the operational amplifier 1310 takes a value from 0 to 5V. On the other hand, in the second range of the rotation angle, the output voltage 1410 takes a constant value of 5V. The output voltage 1410 is attenuated to ½ by the attenuation circuit 1312.

  The output voltage 1400 of the operational amplifier 1320 matches the output voltage of the attenuation circuit 1312 in the first range of the rotation angle. That is, the value ranges from 0 to 2.5 V in the first range of the rotation angle. In the second range of the rotation angle, the output voltage of the operational amplifier 1320 changes according to the change in the output voltage of the second potentiometer 520. The output voltage from the position detection device 200 is as shown by the output voltage 1400 in the figure.

  Also in this example, the output voltage 1400 corresponding to the rotation angle on a one-to-one basis can be obtained. In other words, the output voltage 1400 corresponding to the focal length can be obtained. Further, by attenuating the first potentiometer 510, the power supply voltage for the first potentiometer 510 and the second potentiometer 520 can be shared. In other words, according to the synthesis circuit of the present example, the output voltage from the first potentiometer 510 can be attenuated and supplied as one input potential of the second potentiometer 520, so the first potentiometer 510 and the second potentiometer 520. In addition, it is possible to use one power supply unit that applies a voltage with reference to each one input potential. The attenuation rate of the output voltage is not limited to ½, but may be less than 1.

  As described above with reference to FIGS. 11 to 14, the operational amplifier 1110 and the operational amplifier 1310 function as a potential supply unit that supplies the output potential from the first potentiometer 510 as one input potential of the second potentiometer 520. To do. Specifically, the operational amplifier 1110 and the operational amplifier 1310 operate as a voltage follower circuit. The operational amplifier 1120 and the operational amplifier 1320 generate a voltage output that generates a voltage between one input potential to the first potentiometer and an output potential from the second potentiometer as a voltage output corresponding to the rotation angle on a one-to-one basis. It functions as a part.

  FIG. 15 shows another example of the resistor arrangement of the potentiometer. The second potentiometer 520 of this example includes a resistor 1521 provided at a position corresponding to the entire rotation angle detection range. Except for this point, the resistor arrangement is the same as that illustrated in FIG. That is, the second potentiometer 520 sets the first range of the rotation angle as the target of the detection range.

  FIG. 16 shows an example of the output voltage obtained by the resistor arrangement illustrated in FIG. As a synthesis circuit for synthesizing the output of the potentiometer, the measurement circuit illustrated in FIG. 7 is applied. This figure is an example of an output voltage when V0 = 5 V, R1 = 5 kΩ, R2 = 1.25 kΩ, R3 = 1 kΩ, R4 = 10 kΩ, and R5 = 10 kΩ.

  The output voltage 810 of the first potentiometer 510 is the same as the output voltage illustrated in FIG. That is, the output voltage 810 takes a value from 0 V to 5 V in proportion to the rotation angle in the first range of the rotation angle, and becomes a constant value 5 V in the second range of the rotation angle. The output voltage 1620 of the second potentiometer 520 takes a value from 0 V to 5 V in proportion to the rotation angle in the range from the tele end to the wide end.

  In this example, the output voltage of the second potentiometer 520 is also added to the output voltage 1600 from the position detection device 200 even in the first range of the rotation angle. That is, the output voltage 1600 from the position detection device 200 takes a value from 0 V to 1.8 V in proportion to the rotation angle in the first range of rotation angles, and is proportional to the rotation angle in the second range of rotation angles. The value is from 1.8V to 5V. Even with the resistor arrangement illustrated in FIG. 15, the output voltage 1600 corresponding to the rotation angle on a one-to-one basis can be obtained. That is, it is possible to obtain the output voltage 1600 corresponding to the focal length on a one-to-one basis.

  In the example of FIG. 6, the resistor is provided so that the detection range by the first potentiometer 510 and the detection range by the second potentiometer 520 do not overlap. In the example of FIG. 15, the resistor is provided so that the entire detection range of the first potentiometer 510 is included in the detection range of the second potentiometer 520. However, a resistor may be provided so that a part of the detection range by the first potentiometer 510 is included in the detection range by the second potentiometer 520. That is, the second resistor belonging to the second potentiometer 520 has a position in which it slides in contact with the brush belonging to the second potentiometer 520 when the rotation angle is in the second range, and the rotation angle is at least part of the first range. In some cases, it may be provided at a position in sliding contact with the brush. In the above description, the rotation angle is detected using two potentiometers. However, the rotation angle may be detected using three or more potentiometers having different detection ranges.

  FIG. 17 is a schematic cross-sectional view of the lens unit 20 showing another arrangement example of the potentiometer. This example shows an arrangement example of a potentiometer for directly detecting the lens position in the direction of the optical axis 11 instead of the rotation angle. The potentiometer of this example uses the relative positional relationship of the lens L3 that moves relative to the fixed barrel 10 as a detection target. Specifically, the resistor portion 1700 is provided on the lens holding frame 12c that holds the lens L3, and the brush portion 1710 is provided on the fixing member 1730 along the optical axis 11. The fixing member 1730 is provided fixed to the fixed barrel 10. The fixing member 1730 may be a part of the fixed barrel 10. The lens holding frame 12 c that holds the lens L <b> 3 moves relative to the fixing member 1730 in accordance with the operation of the zoom ring 24.

  When the lens holding frame 12 c moves relative to the fixing member 1730, the brush portion 1710 fixedly provided on the fixing member 1730 slides on the resistor portion 1700. As will be described with reference to FIG. 18, the resistor unit 1700 has two resistors as the resistors of the two potentiometers. The brush unit 1710 has two brushes as respective brushes of the two potentiometers.

  FIG. 18 shows an example of a resistor portion provided on the lens holding frame 12c. Here, the relative positional relationship of the lens L3 is simply referred to as a lens position. The resistor 1811 is a resistor belonging to the first potentiometer that detects the first range of the lens position. The resistor 1821 is a resistor belonging to the second potentiometer that detects the second range of the lens position. The conductor 1812 belongs to the first potentiometer, and is formed at a position where the corresponding brush slides in the second range of the lens position. The conductor 1822 belongs to the second potentiometer and is formed at a position where the corresponding brush slides in the first range of the lens position.

  One end T1 of the resistor 1811 corresponds to the sliding contact position with the brush of the first potentiometer at the tele end. One end W1 of the conductor 1812 corresponds to the sliding contact position with the brush of the first potentiometer at the wide end. One end T2 of the conductor 1822 corresponds to the sliding contact position with the brush of the second potentiometer at the tele end. One end W2 of the resistor 1821 corresponds to the sliding contact position with the brush of the second potentiometer at the wide end. One end T1 of the resistor 1811 and one end T2 of the conductor 1822 are grounded. A voltage V1 is applied to one end W1 of the conductor 1812, and a voltage V2 is applied to one end W2 of the conductor 1822.

  Therefore, when changing from the tele end to the wide end, the output voltage from the first potentiometer changes monotonically from 0 to V1, and then takes a constant value V1. The output voltage of the second potentiometer takes a constant value 0 while the output voltage from the first potentiometer changes, and monotonically from 0V to V2 while the output voltage from the first potentiometer takes a constant value V1. Change. For this reason, the output voltage corresponding to the positional relationship between the lens holding frame 12c and the fixing member 1730 can be generated by applying the synthesis circuit illustrated in FIG. That is, it is possible to generate an output voltage corresponding to the focal length on a one-to-one basis.

  FIG. 19 shows an example in which resistors are arranged on a plurality of lens holding frames. The resistor 1921 and the conductor 1922 correspond to the resistor 1821 and the conductor 1822 illustrated in FIG. That is, the second potentiometer detects the position of the lens holding frame 12c.

  On the other hand, the resistor 1911 and the conductor 1912 belonging to the first potentiometer are provided on the lens holding frame 12b. The resistor 1911 is a resistor belonging to the first potentiometer that detects the first range of the lens position. The conductor 1912 belongs to the first potentiometer, and is formed at a position where the corresponding brush slides in the second range of the z-direction position of the lens. That is, the first potentiometer detects the position of the lens holding frame 12b.

  When the brush belonging to the first potentiometer is located at the boundary position A1 between the resistor 1911 and the conductor 1912, the brush belonging to the second potentiometer is located at the boundary position A2 between the resistor 1921 and the conductor 1922. To position. When the brush belonging to the first potentiometer is positioned at the wide end position W1 in the region where the conductor 1912 is formed, the brush belonging to the second potentiometer is positioned at the wide end position W2.

  Therefore, when it changes from the tele end to the wide end, the output voltage from the first potentiometer is monotonically from 0 to V1 as the brush slides on the resistor 1911 formed in the range from T1 to A1. Change. Thereafter, the brush slides on the conductor 1912 formed from A1 to W2, and takes a constant value V1 until the wide end is reached.

  On the other hand, the output voltage of the second potentiometer takes a constant value 0 while the output voltage from the first potentiometer is changing, and from 0V to V2 while the output voltage from the first potentiometer takes the constant value V1. It changes monotonously. Therefore, by applying the synthesis circuit illustrated in FIG. 7 and the like, it is possible to generate the output voltage corresponding to the lens holding frame 12b and the positional relationship between the lens holding frame 12c and the fixing member on a one-to-one basis. That is, it is possible to generate an output voltage corresponding to the focal length on a one-to-one basis.

  As described in the example of this figure, in a system in which there are two moving members that move relative to the fixed member, the first range of the positional relationship between the two moving members and the fixed member is detected. Therefore, a first potentiometer that detects the relative position of the first moving member with respect to the fixed member is provided, and a second potentiometer that detects the relative position of the second moving member with respect to the fixed member is provided to detect the second range of the positional relationship. May be.

  FIG. 20 shows still another example of the synthesis circuit. The synthesis circuit of this example includes an AD conversion unit 2000 as a part of the lens system control unit 23 as an example. The AD converter 2000 synthesizes the analog output from the first potentiometer 510 and the analog output from the second potentiometer 520 and converts them into a digital output value. Specifically, the AD conversion unit 2000 AD-converts the analog output from the first potentiometer 510 and sets it as the lower bit value of the digital output value, and AD-converts the analog output from the second potentiometer. Set as the value of the upper bits of the digital detection value. Therefore, it is possible to apply a large quantization step to an output from the second potentiometer 520 having a low detection sensitivity while applying a small quantization step to an output from the first potentiometer 510 having a high detection sensitivity. In addition, a digital output value that is substantially proportional to the rotation angle, the lens position, and the like can also be obtained by this synthesis circuit.

  In the above description, the function and operation of the imaging apparatus 100 have been described by taking position information regarding the variable power lens. However, the functions and operations described above can also be applied to the case of detecting position information regarding a lens that is in focus and a shake correction lens. In the above description, the zoom ring 24 and the focus ring 25 are rotated. However, it goes without saying that the functions and operations described above can be applied to position information detection when the lenses L1 to L4 are moved by a motor or the like.

  In the present embodiment, an example of the optical device has been described by taking up the imaging device 100. As imaging devices, interchangeable lens single-lens reflex cameras, non-interchangeable cameras such as compact digital cameras, mirrorless interchangeable-lens cameras, video cameras, mobile phones with imaging functions, portable information terminals with imaging functions, imaging functions A device having an imaging function such as an entertainment device such as an attached game device can be applied. In addition, the optical device may not have an imaging function, and may be realized as a device such as a binoculars, a telescope, a projector device, or a game device. Moreover, as an optical apparatus, the lens unit 20 taken up by this embodiment can be illustrated. That is, an interchangeable lens of a single-lens reflex camera, a lens device incorporated in a device having the imaging function, a lens device incorporated in binoculars, a telescope, or the like can be applied.

  The processing described in relation to the portable imaging device 100 of the present embodiment can be realized by causing each unit of the imaging device 100, for example, the camera system control unit 44, the lens system control unit 23, and the like to operate according to a program. That is, the process can be realized by a so-called computer device. The computer device may load a program for controlling the execution of the above-described process, operate according to the read program, and execute the process. The computer device can load the program by reading a computer-readable recording medium storing the program.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 Fixed lens barrel, 11 Optical axis, 12 Lens holding frame, 20 Lens unit, 22 Aperture, 23 Lens system control part, 24 Zoom ring, 25 Focus ring, 26 Lens mount, 30 Camera unit, 31 Main mirror, 33 Focus plate , 34 Penta prism, 35 Finder optical system, 36 AE sensor, 37 Sub mirror, 39 AF unit, 41 Optical low pass filter, 42 Image sensor, 44 Camera system control unit, 45 Image processing unit, 46 Display unit, 47 Secondary battery, 48 camera mount, 49 operation input unit, 50 camera operation detection unit, 51 memory, 55 camera processing unit, 94 viewfinder display unit

Claims (16)

A detection device that detects a positional relationship between a first member and a second member that moves relative to the first member,
A first potentiometer for detecting a first range of the positional relationship;
A second potentiometer for detecting a second range different from the first range in the positional relationship;
A detection device comprising: a generating unit that combines outputs of the first potentiometer and the second potentiometer to generate a detection output corresponding to the positional relationship on a one-to-one basis. The generation unit generates an analog detection output corresponding to the positional relationship on a one-to-one basis by adding an analog output from the first potentiometer and an analog output from the second potentiometer. 2. The detection device according to 1. The generator is
3. The voltage output generation unit according to claim 2, further comprising: a voltage output generation unit configured to add a voltage output from the first potentiometer and a voltage output from the second potentiometer to generate a voltage output corresponding to the positional relationship on a one-to-one basis. Detection device. The first potentiometer has a detection sensitivity different from that of the second potentiometer,
The detection apparatus according to claim 3, wherein the voltage output generation unit amplifies and adds a voltage output from a potentiometer having a lower detection sensitivity with an amplification factor higher than that of the voltage output from the other potentiometer. The generator is
A potential supply unit for supplying an output potential from the first potentiometer as one input potential of the second potentiometer;
The voltage output generation part which produces | generates the voltage between one input electric potential to the said 1st potentiometer and the output electric potential from the said 2nd potentiometer as a voltage output corresponding to the said positional relationship one to one. 2. The detection device according to 1. The detection apparatus according to claim 5, wherein the potential supply unit includes a voltage follower circuit that inputs an output potential from the first potentiometer and outputs the input potential as one input potential of the second potentiometer. The power supply unit further applies a voltage to the first potentiometer and the second potentiometer with reference to one input potential thereof,
The detection device according to claim 5, wherein the potential supply unit attenuates an output voltage from the first potentiometer and supplies the attenuated output voltage as one input potential of the second potentiometer. The generation unit includes an AD conversion unit that synthesizes an analog output from the first potentiometer and an analog output from the second potentiometer and converts them into a digital output value;
The AD conversion unit AD converts an analog output from the first potentiometer and sets it as a lower bit value of the digital output value, and AD converts an analog output from the second potentiometer to the digital The detection device according to claim 1, wherein the detection value is set as a value of an upper bit of the detected value. The first potentiometer is
A first resistor which is fixedly provided on one of the first member and the second member, and a voltage is applied to both ends;
A first brush that slides on the resistor according to a relative movement amount when the other member of the first member and the second member moves relative to the one member; And
The second potentiometer is
A second resistor which is fixedly provided on one of the first member and the second member, and a voltage is applied to both ends;
A second brush that slides on the resistor according to a relative movement amount when the other member of the first member and the second member moves relative to the one member. And
The first resistor is provided at a position in sliding contact with the first brush when the positional relationship is in the first range,
9. The detection device according to claim 1, wherein the second resistor is provided at least at a position in sliding contact with the second brush when the positional relationship is in the second range. The detection device according to claim 9, wherein the first potentiometer has higher detection sensitivity than the second potentiometer. The first brush and the second brush slide on a resistor corresponding to each brush by a distance corresponding to the amount of movement according to relative movement of the second member with respect to the first member,
The detection device according to claim 10, wherein a length of the first resistor that is in sliding contact with the first brush is shorter than a length of the second resistor that is in sliding contact with the second brush. The second resistor has a position in sliding contact with the second brush when the positional relationship is in the second range, and the second resistor when the positional relationship is in at least a part of the first range. The detection device according to claim 11, wherein the detection device is provided at a position in sliding contact with the brush. The first member is a fixed barrel of the lens device,
The detection device according to claim 1, wherein the second member is a lens holding unit that holds a movable lens that moves relative to the fixed barrel. The detection device according to any one of claims 1 to 12,
An optical lens having one or more movable lenses that move relative to the fixed barrel of the lens device;
The first potentiometer detects a first range of a positional relationship between a lens holding unit that holds the movable lens and the fixed barrel,
The second potentiometer is an optical device that detects a second range of the positional relationship. The movable lens is a variable power lens,
The optical lens has a blur correction lens that can be displaced with respect to the optical axis of the optical lens,
The optical device according to claim 14, wherein the movable lens further includes a control unit that controls a displacement amount of the blur correction lens based on the detection output. Further comprising a focal length calculation unit that calculates a focal length of the optical lens based on the detection output,
The optical device according to claim 15, wherein the control unit controls a displacement amount of the blur correction lens based on the focal length.

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