JP6667794B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging device.

  2. Description of the Related Art An imaging device such as a digital camera having a built-in electronic compass (electronic compass, direction detector) is known. For example, Patent Literature 1 describes a digital camera that detects the orientation of an imaging device based on outputs from an electronic compass and a gyro sensor.

  The digital camera described in Patent Document 1 has a current detection circuit that detects a current flowing in an internal electronic circuit. When the value of the current flowing through the electronic circuit is large, the accuracy of detecting the orientation of the imaging device by the electronic compass decreases due to the magnetic field caused by the current. Therefore, in Patent Literature 1, the direction of the imaging device is calculated using the output of the electronic compass only when the value of the current flowing through the electronic circuit is small.

JP 2015-177366 A

  The digital camera described in Patent Literature 1 has a problem that the accuracy of detecting the orientation of the imaging device by the electronic compass is reduced in accordance with the value of the current flowing through the electronic circuit.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an imaging device capable of accurately detecting an imaging direction.

  An imaging apparatus according to an embodiment of the present invention is an imaging apparatus that forms a light flux from a subject on an imaging element by an imaging optical system and captures an image of a subject on the imaging element, and includes an imaging optical system. And a direction detector that is disposed near the optical system mounting portion and outside the optical path of the light beam and detects the direction of the imaging device.

  According to such a configuration, the direction detector is provided on the front side of the imaging device on which the imaging optical system is mounted. On the other hand, the image pickup device is disposed relatively on the back side of the image pickup apparatus. Therefore, the direction detector is less likely to be affected by a change in the magnetic field generated by driving the imaging device, and a decrease in the detection accuracy of the direction detector can be suppressed.

  In one embodiment of the present invention, for example, the optical system mounting unit has a mounting surface on which the imaging optical system is mounted on the subject side end surface of the imaging device, and the direction detector is near a surface including the mounting surface. Placed in

  In one embodiment of the present invention, for example, the imaging device has a light receiving surface for receiving a light beam having a rectangular shape, and the direction detector is substantially formed from two corners of the four corners of the rectangle which are closer to the direction detector. They are located at the same distance.

  In one embodiment of the present invention, the imaging device is disposed, for example, between the optical system mounting unit and the imaging device, and transmits a light beam passing through the imaging optical system in a direction perpendicular to the optical axis of the imaging optical system. It further includes a reflecting portion for reflecting. In this configuration, the direction detector is disposed at a position where the reflection unit is displaced from the optical axis of the imaging optical system in a direction in which the light flux is reflected.

  In one embodiment of the present invention, the imaging device further includes, for example, an erecting optical system that erects the subject image reflected by the reflection unit. In this configuration, the direction detector is arranged on the opposite side of the erecting optical system from the image sensor.

  In one embodiment of the present invention, the imaging device further includes, for example, a resin protection unit that protects the erecting optical system. In this configuration, the orientation detector is mounted between the protection unit and the erecting optical system.

  In one embodiment of the present invention, the imaging device further includes, for example, an electromagnetic displacement unit that displaces the imaging device by an electromagnetic force. In this configuration, the distance from the direction detector to the electromagnetic displacement unit is longer than the shortest distance from the direction detector to the image sensor.

  According to the present invention, there is provided an imaging apparatus capable of accurately detecting an imaging direction.

It is a block diagram of an imaging device concerning one embodiment of the present invention. 1 is an external view of a main body of an imaging device according to an embodiment of the present invention. FIG. 2 is a transparent view of the main body of the imaging device according to the embodiment of the present invention as viewed from the front. FIG. 2 is a transparent view of the main body of the imaging device according to the embodiment of the present invention as viewed from above. FIG. 3 is a transparent view of a main body of the imaging device according to the embodiment of the present invention as viewed from the right.

  Hereinafter, an imaging device according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, a lens detachable digital single-lens reflex camera will be described as an embodiment of the present invention. Note that the imaging device is not limited to a digital single-lens reflex camera with a detachable lens, for example, a mirrorless single-lens camera, a compact digital camera, a video camera, a camcorder, or another device having an imaging function, or any of these devices. You may replace with the system which combined or the system which has the function equivalent to these apparatuses.

  FIG. 1 is a block diagram illustrating a schematic configuration of an imaging device 1 according to the present embodiment. The imaging device 1 includes a main body 100 and a lens unit 200. The lens unit 200 is detachably connected to the main body 100.

  The main body 100 includes a control unit 110, an observation optical system 111, an imaging unit 112, an image processing unit 113, a display device 114, a memory card interface 115, a flash memory 116, an operation unit 117, an acceleration sensor 118, a GPS (Global Positioning System) sensor. 119, a gyro sensor 120, a wireless communication unit 121, and an electronic compass 130. The observation optical system 111 includes an erecting optical system 111a and an eyepiece optical system 111b. The imaging unit 112 includes an imaging element 112a and a driving unit 112b. The lens unit 200 includes an imaging optical system 210. In the present embodiment, for the sake of convenience, components and configurations unique to the device (for example, wiring, a part of the device casing, and the like), whose description may be omitted, are not illustrated or described as appropriate. Simplify.

  The control unit 110 controls each unit of the imaging device 1 based on a user operation on the operation unit 117. The operation unit 117 includes various switches necessary for the user to operate the imaging apparatus 1, such as a power switch, a release switch, and an imaging mode switch.

  The image sensor 112a is a single-chip color CCD (Charge Coupled Device) image sensor having a Bayer array of color filters. The image sensor 112a converts the subject image formed on the light receiving surface by the imaging optical system 210 into an image signal and outputs the image signal. The image sensor 112a is not limited to a CCD image sensor, but may be a CMOS (Complementary Metal Oxide Semiconductor) image sensor or another type of image sensor. In addition, a color filter array other than the Bayer array may be employed, or a three-plate or plane-sequential imaging apparatus may be used instead of the imaging element 112a.

  The image processing unit 113 generates image data (still image data and moving image data) based on the imaging signal generated (photoelectric conversion) by the imaging element 112a, and generates an image file of a predetermined format based on the image data. And output. Further, the image processing unit 113 generates screen data to be displayed on the display device 114 based on the image data, and generates and outputs a video signal of a predetermined format based on the screen data.

  The display device 114 is, for example, an LCD (Liquid Crystal Display), and performs screen display based on a video signal output from the image processing unit 113.

  The memory card interface 115 has a card slot into which a memory card is removably inserted, and writes and reads data such as image files to and from the memory card inserted into the card slot.

  Further, data such as an image file can be stored in the flash memory 116 for a long time. Reading and writing of data such as an image file is performed to a storage destination (memory card or flash memory 116) set by a user operation.

  The acceleration sensor 118 detects acceleration in three orthogonal axes directions of the main body 100 (X-axis, Y-axis, and Z-axis directions described later).

  The GPS sensor 119 receives GPS signals from a plurality of GPS satellites above the main body 100 and three-dimensionally positions the current position of the main body 100 based on the received GPS signals.

  The gyro sensor 120 detects angular velocities around the optical axis (X axis) of the main body 100 and around two orthogonal axes (Y axis, Z axis) perpendicular to the optical axis (X axis).

  The wireless communication unit 121 is used for the main body 100 imaging device 1 to perform wireless communication with an external device. The wireless communication unit 121 is, for example, a communication interface that provides a Wi-Fi wireless communication function.

  An electronic compass (electronic compass, direction detecting element, geomagnetic sensor) 130 detects the strength of a magnetic field (geomagnetism) in three orthogonal directions of the main body 100. The details of the electronic compass 130 will be described later.

  FIG. 2 is an external view of the main body 100 of the imaging device 1. As shown by the coordinate axes in FIG. 2, the optical axis direction (the direction from the main body 100 toward the subject) is the X-axis positive direction, the left side toward the subject is the Y-axis positive direction, and the direction perpendicular to the X-axis and Y-axis directions. The direction (vertically upward) is defined as the positive direction of the Z axis. Further, the positive direction of the Z-axis is referred to as upward (the negative direction of the Z-axis is downward), the positive direction of the Y-axis is referred to as left (the negative direction of the Y-axis is right), and the positive direction of the X-axis is referred to as front (the negative direction of the X-axis is referred to as rear).

  The main body 100 includes a frame (not shown) and a main body case 10 (exterior) formed from a plurality of exterior members attached to the frame. An upper cover 11 made of resin is attached to an upper part of the main body case 10.

  On the front side of the main body 100, there is a mounting section 20 to which the lens unit 200 is mounted. The mounting section 20 has an annular mounting surface 21. The lens unit 200 is fixed to the mounting portion 20 by bringing the connection surface of the lens unit 200 into contact with the mount surface 21 of the main body 100 and operating a lock mechanism (not shown). The mounting section 20 has an opening 22 that communicates the outside and the inside of the main body 100. The light beam from the subject passes through the lens unit 200 and the opening 22 and enters the inside of the main body 100.

  3 to 5 are transparent views of the main body 100 of the imaging device 1. FIG. FIG. 3 is a transparent view when the main body 100 is viewed from the front. FIG. 4 is a transparent view when the main body 100 is viewed from above. FIG. 5 is a transparent view when the main body 100 is viewed from the right side. 3 to 5, electrical wiring is omitted for convenience of simplifying the drawings. In addition, only the outline of the main body case 10 and the upper cover 11 is shown for convenience of simplifying the drawing.

  As shown in FIGS. 3 to 5, the main body 100 includes a main mirror 30, a focus plate 31, an observation optical system 111 (erecting optical system 111a, eyepiece optical system 111b), a finder (window) 32, and an imaging unit 112 (imaging). It includes an element 112a, a driving section 112b, a front yoke 112c, a rear yoke 112d), and a circuit board 33. Further, the main body 100 includes a GPS sensor 119, a wireless communication unit 121, and an electronic compass 130 on the upper part. 3 to 5, the display device 114, the memory card interface 115, the flash memory 116, the acceleration sensor 118, the gyro sensor 120, the wiring, the frame, and the like are omitted for the sake of simplicity.

  The lens unit 200 is mounted on the front side of the mounting unit 20. FIG. 5 shows the optical axis AX1 of the lens unit 200 by a two-dot chain line. A light flux from the subject (subject light flux) passing through the lens unit 200 enters the main body 100 along the optical axis AX1. When the user observes the subject image through the viewfinder 32, the main mirror 30 is arranged on the optical axis AX1. The subject light flux entering the main body 100 is reflected by the main mirror 30 toward the focus plate 31. The optical axis AX2 shown in FIG. 5 is the optical axis of the optical system after being reflected by the main mirror 30. The subject light beam is diffused by the focus plate 31 and is incident on the erecting optical system 111a. The erecting optical system 111a is, for example, a penta roof prism. The subject image (real image) once formed on the focus plate 31 becomes an erect image by being reflected on each reflection surface of the penta roof prism, and is incident on the eyepiece optical system 111b. The user can observe the subject image (virtual image) re-imaged by the eyepiece optical system 111b by looking through the finder 32. When a subject image is captured by the image sensor 112a, the main mirror 30 is retracted from an optical path centered on the optical axis AX1 from the lens unit 200 to the image sensor 112a. As a result, the subject light flux is formed on the imaging surface of the image sensor 112a, and a subject image is captured.

  The image sensor 112a is attached to the image sensor holding member 112a1. As shown by a broken line in FIG. 3, the image sensor 112a has a rectangular image surface 112a2. The image sensor 112a captures a subject image formed on the imaging surface 112a2 by the lens unit 200. The driving unit 112b of the imaging unit 112 moves the imaging element holding member 112a1 and the imaging element 112a in two directions perpendicular to the optical axis (X axis) in two orthogonal directions (Y-axis direction and Z-axis direction) and in a YZ plane rotation direction. Let it. The drive unit 112b is an electromagnetic actuator having a plurality of permanent magnets 112b1 and a plurality of coils and a coil 112b2. Each permanent magnet 112b1 is attached to a corresponding front yoke 112c, and each front yoke 112c is fixed to the main body 100. The coil 112b2 is attached to the image sensor holding member 112a1. A rear yoke 112d is provided between the imaging element holding member 112a1 and the circuit board 33. The rear yoke 112d is fixed to the main body 100. The rear yoke 112d is arranged to face the plurality of front yokes 112c. In FIG. 3, the illustration of the front yoke 112c and the rear yoke 112d is omitted, and the permanent magnet 112b1 is indicated by a two-dot chain line. In FIG. 5, the illustration of the permanent magnet 112b1 and the coil 112b2 is omitted.

  The permanent magnet 112b1 and the coil 112b2 are arranged to face each other. The imaging element holding member 112a1 is movably attached to the front yoke 112c and the rear yoke 112d. Therefore, when a current is supplied to the coil 112b2, the imaging element 112a can be displaced together with the imaging element holding member 112a1 by electromagnetic force.

  The displacement of the image sensor 112a by the drive unit 112b is used in a camera shake correction function and an astronomical object automatic tracking shooting function. Details of the camera shake correction function and the celestial body automatic tracking shooting function are described in Japanese Patent Application Laid-Open No. 2010-122672.

  When the camera shake correction function is enabled, the control unit 110 detects vibration (camera shake) of the main body 100 based on the detection results of the acceleration sensor 118 and the gyro sensor 120. Then, the control unit 110 controls the driving unit 112b to displace the image sensor 112a in a direction to cancel the detected vibration. As a result, an image with little image blur is captured.

  When the celestial body automatic tracking shooting function is enabled, the control unit 110 detects the position and orientation (imaging azimuth) of the main body 100 from the detection results of the GPS sensor 119, the electronic compass 130, the acceleration sensor 118, and the gyro sensor 120. Further, the control unit 110 calculates the movement of the celestial body with respect to the main body 100 based on the information on the position and the orientation of the main body 100. Then, the control unit 110 controls the driving unit 112b to displace the image sensor 112a in accordance with the movement of the celestial body. Thus, even if the exposure time is lengthened, a point image of a star is captured without flowing the star image. For the purpose of detecting an approximate imaging direction in normal imaging, an azimuth detection error of about ± 10 degrees is sufficiently allowed. However, when celestial body automatic tracking imaging is performed using the detection result of the electronic compass 130 (specifically, celestial body tracking data is calculated based on the azimuth information detected by the electronic compass 130), the azimuth detection error is reduced. Even at ± several degrees, a tracking error that cannot be ignored occurs depending on the exposure time, and the astronomical image moves. Therefore, the effect of the celestial body automatic tracking photographing function is strongly affected by the detection accuracy of the direction of the main body 100 by the electronic compass 130, so that a higher azimuth detection accuracy than before is required.

  The electronic compass 130 has a rectangular parallelepiped shape, and is mounted on the electronic compass board 131. The electronic compass board 131 is connected to the circuit board 33 via a flexible cable (not shown). Further, the electronic compass 130 is bonded and fixed in a state where the outer surface thereof is applied to the electronic compass holding member 132. Thus, the electronic compass 130 is positioned with respect to the electronic compass holding member 132. The electronic compass holding member 132 is attached after being positioned inside the upper cover 11. Thereby, the electronic compass 130 can be accurately positioned with respect to the main body 100. The upper cover 11 is made of resin and is substantially a non-magnetic material. Therefore, the upper cover 11 can protect the electronic compass 130 without lowering the azimuth detection accuracy.

  After the electronic compass 130 is attached to the main body 100, the adjustment of the offset amount and the sensitivity of the signal value is performed. However, if electromagnetic noise or a change in the magnetic field occurs near the electronic compass 130, the detection accuracy of the orientation of the main body 100 by the electronic compass 130 decreases. The electromagnetic noise is generated from, for example, the imaging element 112a and the circuit board 33. Further, a change in the magnetic field occurs when a current is supplied to the coil 112b2 or when a magnetic material included in the permanent magnet 112b1 or the imaging element holding member 112a1 is moved by an electromagnetic force. For this reason, in the present embodiment, the electronic compass 130 is disposed at a position relatively insensitive to electromagnetic noise and changes in the magnetic field.

  In the present embodiment, as shown in FIGS. 4 and 5, the electronic compass 130 is arranged near the mounting unit 20. Specifically, the electronic compass 130 is arranged near a surface including the mount surface 21 of the mounting unit 20. The mounting surface 21 is a surface provided on the front side of the main body 100. On the other hand, elements that change the magnetic field, such as the circuit board 33, the image sensor 112a, and the permanent magnet 112b1, are provided on the relatively rear side in the main body 100. Therefore, by disposing the electronic compass 130 near the surface including the mounting surface 21, a change in the magnetic field around the electronic compass 130 due to the circuit board 33, the image sensor 112a, the permanent magnet 112b1, and the like can be suppressed. Thereby, it is possible to suppress a decrease in the detection accuracy of the imaging azimuth by the electronic compass 130.

  As shown in FIGS. 3 and 5, the electronic compass 130 is disposed at a position shifted upward with respect to the optical axis AX1 of the lens unit 200. On the upper part of the main body 100, optical members such as the erecting optical system 111a and the eyepiece optical system 111b are arranged. Therefore, the size of the electronic circuit included in the upper part of the main body 100 is smaller than that of the lower part of the main body 100 including the circuit board 33 and the imaging element 112a. As described above, by disposing the electronic compass 130 in a region where the size of the electronic circuit is small, it is possible to suppress the influence of a change in the magnetic field generated by driving the electronic circuit on the electronic compass 130.

  In addition, as shown in FIG. 5, the electronic compass 130 is arranged on the opposite side of the image pickup device 112a with respect to the erecting optical system 111a. Thus, the electronic compass 130 is less susceptible to a change in the magnetic field generated by the image sensor 112a.

  In addition, as shown in FIGS. 3 to 5, the driving unit 112b is arranged at a position farther from the electronic compass 130 than the image sensor 112a. In other words, the distance from the electronic compass 130 to the drive unit 112b is set to be larger than the shortest distance from the electronic compass 130 to the image sensor 112a. The drive section 112b has a permanent magnet 112b1 and a coil 112b2 for generating a magnetic field. Therefore, the change in the magnetic field caused by the driving unit 112b is larger than the change in the magnetic field caused by the displacement of the image sensor 112a. Therefore, by arranging the drive unit 112b away from the electronic compass 130, it is possible to suppress the influence of the change in the magnetic field generated by the drive unit 112b on the electronic compass 130.

  In addition, as shown in FIG. 3, the electronic compass 130 is disposed at a position approximately the same distance away from the upper left corner C1 and the upper right C2 near the electronic compass 130 among the four corners C1 to C4 of the imaging surface 112a2. I have. At this time, the imaging surface 112a2 is symmetrically arranged with respect to the electronic compass 130. If the magnetic field changes due to the current flowing through the image sensor 112a while the electronic compass 130 is arranged at a position shifted to the left or right with respect to the imaging surface 112a2, the electronic compass 130 Or from one direction. On the other hand, in the present embodiment, it is arranged on a plane passing through the center in the left-right direction of the imaging surface 112a2. Therefore, when a change in the magnetic field occurs due to the current flowing in the image sensor 112a, the electronic compass 130 is equally affected by the change in the magnetic field from the left half and the right half of the image sensor 112a. Thus, the influence of the change in the magnetic field in the left and right direction caused by the image sensor 112a on the electronic compass 130 can be suppressed.

  The above is the description of the exemplary embodiment of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiments of the present invention also include embodiments exemplarily illustrated in the specification or contents obtained by appropriately combining obvious embodiments and the like.

Reference Signs List 1 imaging device 100 main body 10 main body case 11 upper cover 20 mounting portion 21 mounting surface 22 opening 30 main mirror 31 focus plate 32 finder 33 circuit board 110 control unit 111 observation optical system 111a erecting optical system 111b eyepiece optical system 112 imaging unit 112a Image sensor 112a1 Image sensor holding member 112b Driver 112b1 Permanent magnet 112b2 Coil 112c Front yoke 112d Rear yoke 113 Image processor 114 Display device 115 Memory card interface 116 Flash memory 117 Operation unit 118 Acceleration sensor 119 GPS sensor 120 Gyro sensor 121 Wireless communication Unit 130 Electronic compass 131 Electronic compass board 132 Electronic compass holding member 200 Lens unit 210 Imaging optical system

Claims (5)

An imaging apparatus forms an image on the image sensor, for imaging an object image on the imaging device by the imaging optical system a light beam from an object,
An optical system mounting unit to which the imaging optical system is mounted,
An orientation detector arranged at a position outside the optical path of the light beam and detecting the orientation of the imaging device,
A reflection unit that is disposed between the optical system mounting unit and the image sensor, and reflects a light beam that has passed through the imaging optical system in a direction perpendicular to the optical axis of the imaging optical system.
An erecting optical system that erects the subject image reflected by the reflection unit,
Equipped with a,
The orientation detector,
The side on which the erecting optical system is located with respect to the optical axis of the imaging optical system, and the side on which the optical system mounting section is located with respect to the optical axis of light incident on the erecting optical system from the reflecting section. Placed in
That it is fixed to the exterior of the imaging device,
Imaging device. The optical system mounting unit has a mounting surface on which the imaging optical system is mounted on the subject side end surface of the imaging device,
The orientation detector is disposed near a surface including the mounting surface,
The imaging device according to claim 1. The image sensor has a rectangular light-receiving surface for receiving the light beam,
The orientation detector is arranged at a position substantially spaced the same distance from the second corner of the order of proximity to said orientation detector of the four corners of the rectangular,
The imaging device according to claim 1. Further comprising a resin protection portion for protecting the erecting optical system,
The orientation detector is attached between the protection unit and the erecting optical system,
The imaging device according to claim 1 . The image pickup device further includes an electromagnetic displacement unit that displaces by an electromagnetic force,
The distance from the direction detector to the electromagnetic displacement unit is longer than the shortest distance from the direction detector to the imaging device,
The imaging apparatus according to any one of claims 1 to 4.

Images