JP5543762B2 - Camera system - Google Patents

Description

  The present invention relates to a camera system that obtains a stereoscopic image by photographing a subject from a plurality of viewpoints having parallax.

  A technique for capturing a stereoscopically-capable still image or a stereoscopically-capable moving image (hereinafter simply referred to as a stereoscopic image) by capturing the same subject from a plurality of different viewpoints having parallax is known. . The stereoscopic image is also referred to as a stereo image, a 3D image, or a stereoscopic image.

  As a method for photographing a stereoscopic image, for example, as disclosed in Japanese Patent Laid-Open No. 11-27702, a method of photographing using a camera including two photographing lenses, or for example, Japanese Patent Laid-Open No. 2006-33395 is disclosed. As disclosed in the official gazette, a method is known in which two cameras are placed apart and photographed.

JP-A-11-27702 JP 2006-33395 A

  In order to capture a stereoscopic image having a parallax (parallax amount) that allows a person to feel a stereoscopic effect (a sense of depth), the baseline length and the convergence angle are set according to the distance between the camera and the subject (subject distance). Must be changed. For example, when the subject distance is long, such as when shooting landscapes or buildings, the parallax between images from different viewpoints must be increased by increasing the base length.

  On the other hand, when the subject distance is short, for example, close-up, the base line length must be shortened. This is because when the subject distance is shorter than the base line length, the parallax between the images of different viewpoints becomes too large and stereoscopic viewing becomes impossible. In addition, when the subject distance is short, the convergence angle must be changed so that the same subject can be contained in images of different viewpoints.

  For example, in the camera disclosed in Japanese Patent Application Laid-Open No. 11-27702, since the baseline length and the convergence angle are fixed, it is easy to obtain such information at the time of shooting. However, since the baseline length and the convergence angle cannot be changed according to the subject distance, stereoscopic images cannot be taken for various subjects.

  Moreover, in the method of disposing and photographing two cameras as disclosed in Japanese Patent Laid-Open No. 2006-33395, the baseline length and the convergence angle can be changed to appropriate values according to the subject distance. it can. However, it is difficult to accurately arrange two cameras arranged separately so that a stereoscopic image can be obtained.

  The present invention has been made in view of the above-described problems, and is a camera capable of taking a stereoscopic image easily by setting the base line length to an appropriate value in accordance with a change in subject distance and a change in imaging lens. The purpose is to provide a system.

The camera system of the present invention includes a first photographing lens that forms an optical image of a subject, and a first imaging element that is disposed at an imaging position of the first photographing lens, and generates an image of the subject. A first camera having a first imaging unit, a second photographic lens that is detachably attached to the first camera via a coupling unit, and forms an optical image of the subject, and the second photographic lens A second imaging unit that has a second imaging element that is disposed at the imaging position and has a light receiving surface different from the first imaging element and generates an image of the subject, and the first imaging lens. comprising a second camera having a mechanism for adjusting the angle between the optical axis of the optical axis the second imaging lens, and a detector for detecting the angle, the image plane of the second imaging lens node distance from the nodal point, the angle and the first camera or the second Based on the position information recorded in the camera, characterized by having a calculation unit for calculating a relative position of the nodes of the node and the second imaging lens of the first imaging lens.

  According to the present invention, it is possible to provide a camera system in which the base line length can be set to an appropriate value in accordance with a change in subject distance and a change in imaging lens, and a stereoscopic image can be easily taken.

It is a perspective view which shows the front side of a camera system. It is a perspective view which shows the back side of a camera system. It is a figure explaining the structure of a 1st camera. It is a figure explaining the structure of a 2nd camera. 2 is a top view showing an arrangement of a subject and a camera system 1. FIG. 2 is a top view showing an arrangement of a subject and a camera system 1. FIG. It is a figure which shows the relationship between a to-be-photographed object distance and a parallax angle when a human sees with both eyes. FIG. 6 is a diagram in which the parallax amount in the case of a subject distance of 3 m is converted into a parallax amount on the image field side at each subject distance by a nodal distance. It is a figure which shows the relationship between the image pick-up element space | interval of a camera system 1, and the amount of parallax. It is a flowchart explaining operation | movement of a 1st camera.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each drawing used for the following description, the scale is different for each component in order to make each component large enough to be recognized on the drawing. It is not limited only to the quantity of the component described in the drawing, the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.

  The camera system 1 of the present embodiment is an apparatus that can capture at least one of a stereoscopically viewable still image and a stereoscopically viewable moving image (hereinafter simply referred to as a stereoscopic image). The camera system 1 includes two cameras for photographing the same subject from a plurality of different viewpoints having parallax.

  In the present embodiment, as shown in FIG. 1, the camera system 1 includes a first camera 10 and a second camera 300 that can be separated from each other via a coupling portion described in detail later. Moreover, although mentioned later in detail, the 1st camera 10 and the 2nd camera 300 are comprised so that communication is possible by the communication part.

  The coupling unit is for mechanically coupling the first camera 10 and the second camera 300. As shown in FIGS. 1 and 2, the coupling unit mechanically connects the first camera 10 and the second camera 300 with the intermediate member 400 disposed between the first camera 10 and the second camera 300. Can also be combined. FIG. 1 shows a state in which the first camera 10 and the second camera 300 are mechanically coupled via the intermediate member 400.

  First, the configuration of the first camera 10 will be described. As shown in FIG. 3, the first camera 10 forms a subject image on a body unit 100 that holds a charge coupled device (hereinafter referred to as a CCD) 117 that is an imaging device, and a light receiving surface (pixel region) of the CCD 117. And a lens unit 200 that holds a photographing lens 202 for imaging. The lens unit 200 is detachable through a lens mount (not shown) provided on the front surface of the body unit 100.

  Note that the CCD 117 may be an imaging device of a form called, for example, a CMOS (complementary metal oxide semiconductor) sensor that outputs an electrical signal corresponding to light incident on the light receiving surface at a predetermined timing.

  In the following description, an axis parallel to the optical axis O1 of the photographing lens 202 is defined as the Z direction, and two directions orthogonal to each other on a plane orthogonal to the optical axis O1 (a plane parallel to the light receiving surface of the CCD 117) are defined as the X axis and The Y axis is assumed. In this embodiment, as an example, the CCD 117 has a rectangular light receiving surface, the X axis is parallel to the long side of the light receiving surface, and the Y axis is parallel to the short side.

  In the first camera 10 of the present embodiment, the operation of the lens unit 200 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 201 disposed in the lens unit 200. The operation of the body unit 100 is controlled by a body control microcomputer (hereinafter referred to as “Bucom”) 101 disposed in the body unit 100.

  The Lucom 201 and Bucom 201 are electrically connected to each other via the communication connector 102 in a state where the lens unit 200 is mounted on the body unit 100. The Lucom 201 is configured to operate in cooperation with the Bucom 201 in a dependent manner. As will be described in detail later, Bucom 201 constitutes a control unit, an identification unit, and a calculation unit in the present invention.

  The lens unit 200 may be configured integrally with the body unit 100. The operation of the lens unit 200 may be controlled only by the Bucom 201.

  The lens unit 200 includes a photographic lens 202 and a diaphragm 203. In the present embodiment, the photographing lens 202 includes a focus lens 202a and a variable power lens 202b. The focus lens 202a is driven by an actuator such as a stepping motor (not shown) provided in the lens driving mechanism 204. The variable magnification lens 202b is driven by an actuator such as a stepping motor (not shown) provided in the zoom drive mechanism 206. The diaphragm 203 is driven by an actuator such as a stepping motor (not shown) provided in the diaphragm driving mechanism 205.

  The in-focus distance, focal length, and aperture value of the photographic lens 202 are detected by a position encoder (not shown) or the like, and input to the Bucom 201 via the Lucom 201 and the communication connector 102.

  In addition to the Bucom 201, the body unit 100 includes a first imaging unit 116, a power supply circuit 135, a nonvolatile memory 128 that is a storage unit, a coupling unit 180, a communication connector 181 that is a communication unit, and the like. . The first imaging unit 116 is for photoelectrically converting a subject image formed by the photographing lens 202 to obtain a first image, and is disposed on the image side (rear side) of the photographing lens 202. In the present embodiment, the first imaging unit 116 includes a CCD 117, an optical low-pass filter (LPF) 118 disposed on the front side thereof, and a dust filter 119.

  A piezoelectric element 120 is attached to the peripheral edge of the dust filter 119. The piezoelectric element 120 is configured to vibrate the dust filter 119 at a predetermined frequency determined by the size and material by the dust filter control circuit 121. When the dust filter 119 vibrates, dust attached to the filter surface can be removed.

  Note that the LPF 118 and the dustproof filter 119 may be appropriately disposed as necessary, and the first imaging unit 116 may be configured by only the CCD 117 that is an imaging element.

  A shutter 108 is disposed on the front side of the first imaging unit 116. The body unit 100 also includes a shutter charge mechanism 112 that charges a spring that drives the front curtain and rear curtain of the shutter 108, and a shutter control circuit 113 that controls the movement of the front curtain and rear curtain. . Although the shutter 108 of this embodiment is a focal plane shutter, the shutter 108 may be a lens shutter.

  In addition, the first camera 10 in this embodiment includes a CCD interface circuit 122 connected to the CCD 117, a liquid crystal monitor 123, an image processing controller 126 that performs image processing using an SDRAM 124, a Flash ROM 125, or the like that functions as a storage area. The electronic recording display function can be provided together with the electronic imaging function.

  Here, the recording medium 127 is an external recording medium such as various memory cards or an external HDD, and is mounted so as to be communicable and replaceable with the body unit 100 via a communication connector. Then, image data obtained by photographing with the first imaging unit 116 is recorded on the recording medium 127.

  As the other storage area, a nonvolatile memory 128 that stores a predetermined control parameter necessary for camera control, for example, a storage unit made of an EEPROM, is provided so as to be accessible from the Bucom 201. As will be described in detail later, the nonvolatile memory 128 stores shape information of the first camera 10 and the like necessary for obtaining the baseline length of the stereoscopic image.

  The Bucom 201 is connected to an operation display LED 130 for notifying the user of the operation state of the first camera 10 by display output, a camera operation SW 131, and a strobe control circuit 133 that drives the external strobe 1. The camera operation SW 131 is a switch group including operation buttons necessary for operating the first camera 10 such as a release SW, a mode change SW, and a power SW. Further, in the body unit 100, a battery 134 as a power source, and a power supply circuit 135 that converts the voltage of the battery 134 into a voltage required by each circuit unit constituting the first camera 10 and supplies the converted voltage. There is also provided a voltage detection circuit (not shown) for detecting a voltage change when current is supplied from an external power source via a jack (not shown).

  Each part of the 1st camera 10 comprised as mentioned above operates as follows roughly. First, the image processing controller 126 takes in image data from the CCD 117 by controlling the CCD interface circuit 122 in accordance with an instruction from the Bucom 201. This image data is converted into a video signal by the image processing controller 126 and output and displayed on the liquid crystal monitor 123. The user can use the display image on the liquid crystal monitor 123 as a finder image for confirmation of the subject and can check the shooting screen by displaying the shot image.

  The SDRAM 124 is a memory for temporarily storing image data, and is used as a work area when image data is converted. The image data is stored in the recording medium 127 after being converted into the JPEG format or the like.

  Also, the first camera 10 of the present embodiment is a so-called contrast detection type auto that moves the focus lens 202a based on the contrast value of a predetermined area (focus area) of image data generated by the image processing controller 126. Focus.

  The coupling unit 180 is for detachably mechanically coupling the body unit 100 and the second camera 300 of the first camera 10 or the body unit 100 and the intermediate member 400. In the present embodiment, the connecting portion 180 has a shape generally called an accessory shoe or a hot shoe, to which an external strobe device can be attached and detached. The coupling unit 180 is provided with a strobe contact 136 for electrically connecting the external strobe device and the strobe control circuit 133.

  In addition, the structure of the coupling | bond part 180 is not restricted to this embodiment, What is necessary is just the structure which couple | bonds the 1st camera 10 and the 2nd camera 300 or the intermediate member 400 mechanically. For example, the coupling unit 180 may have a configuration using a screw mechanism or a bayonet mechanism.

  The coupling unit 180 is provided with a communication connector 181 that constitutes a communication unit for performing communication between the first camera 10 and the second camera 300. The communication connector 181 has a configuration for electrically connecting the first camera 10 and the second camera 300 when the first camera 10 and the second camera 300 are mechanically coupled via the coupling unit 180. .

  In the present embodiment, the communication connector 181 is provided with a terminal for supplying power from the first camera 10 to the second camera 300 in addition to a terminal for communication between the first camera 10 and the second camera 300. . Note that when the second camera 300 includes a power source independent of the first camera 10, the communication connector 181 performs communication between the first camera 10 and the second camera 300 using light, and is used for optical communication. It may be a connector.

  The first camera 10 of the present embodiment is a so-called camera shake correction mechanism that prevents image blur on the light receiving surface by moving the CCD 117 in the X-axis direction and the Y-axis direction according to the movement of the first camera 10. It is equipped with a so-called anti-vibration mechanism.

  The anti-vibration mechanism includes an X-axis gyro 160, a Y-axis gyro 161, an anti-vibration control circuit 162, an X-axis actuator 163, a Y-axis actuator 164, an X frame 165, a Y frame 166, a frame 167, a position detection sensor 168, and an actuator drive circuit. 169.

  The frame 167 is fixed to the body unit 100, and the X frame 165 is supported by the frame 167 so as to be movable in the X-axis direction. Further, the Y frame 166 holding the CCD 117 is supported by the X frame 165 so as to be movable in the Y axis direction. The X-axis actuator 163 and the Y-axis actuator 164 are configured to drive the X frame 165 and the Y frame 166 in the X axis direction and the Y axis direction, respectively. The position control of the X frame 165 and the Y frame 166 is performed by a position detection sensor 168 that detects the positions of the X frame 165 and the Y frame 166 and an actuator drive circuit 169 that controls the operations of the X axis actuator 163 and the Y axis actuator 164. Is called.

  The X-axis gyro 160 detects the angular velocity of rotation (blur) around the X axis of the first camera 10, and the Y-axis gyro 161 detects the angular velocity of rotation of the first camera 10 around the Y axis. The image stabilization control circuit 162 calculates a camera shake compensation amount from the detected angular velocity of the first camera 10 and moves the CCD 117 so as to compensate for the shake. In the vibration isolation mechanism, the configuration of the actuator that moves the CCD 117 is not particularly limited, such as a rotary motor, a linear motor, or an ultrasonic motor.

  Next, the configuration of the second camera 300 will be described. As shown in FIG. 4, the second camera 300 includes a CCD 317 and a photographing lens 302 that forms a subject image on the light receiving surface of the CCD 317. In the present embodiment, in the second camera 300, a body portion that holds the CCD 317 and a lens barrel portion that holds the photographing lens 302 are integrally configured. In the following description, the optical axis of the photographing lens 302 is referred to as an optical axis O2.

  Note that the second camera 300 has a CCD 317 (imaging device) having a smaller light receiving surface than the first camera 10. More specifically, the number of pixels of the CCD 317 is the same as that of the CCD 117, and the size of the light receiving surface is 1/2 that of the CCD 117. That is, the area (pixel area) of the light receiving surface of the CCD 317 is ¼ that of the CCD 117.

  The focal lengths of the photographing lens 202 and the photographing lens 302 are determined so that the angles of view photographed by the CCD 117 and the CCD 317 coincide with each other. That is, the focal length of the photographic lens 302 is ½ of the focal length of the photographic lens 202.

  In the present embodiment, since the lens unit 200 can be replaced, it is preferable that the photographing lens 302 has a variable focal length range that can cope with a change in focal length accompanying the replacement of the lens unit 200. For example, when the focal length of the predetermined photographing lens 202 can be changed between fW1 [mm] at the wide-angle end and fT1 [mm] at the telephoto end, the variable range of the focal length of the photographing lens 302 is the wide-angle end. Is shorter than fW1 / 2 [mm], and the telephoto end is preferably longer than fT1 / 2 [mm].

  Similar to the first camera 10 described above, the lens barrel of the second camera 300 is configured to include a Lucom 301, a photographing lens 302, and a diaphragm 303, which are control units. The photographing lens 302 includes a focus lens 302a and a variable power lens 302b. The focus lens 302 a is driven by an actuator such as a stepping motor (not shown) provided in the lens driving mechanism 304. The variable power lens 302b is driven by an actuator such as a stepping motor (not shown) provided in the zoom drive mechanism 306. The diaphragm 303 is driven by an actuator such as a stepping motor (not shown) provided in the diaphragm driving mechanism 305.

  Further, unlike the first camera 10, the second camera 300 of the present embodiment includes a so-called lens shutter type shutter 308. That is, the shutter 308 is disposed in the lens barrel portion. The shutter 308 is a general type in which a light shielding blade biased by a spring is driven by a plunger, and the shutter charge mechanism 112 of the first camera 10 is unnecessary. Note that the shutter 308 may be of a focal plane shutter type, similar to the first camera 10.

  The in-focus distance, the focal length, and the aperture value of the photographic lens 302 are detected by a position encoder (not shown) or the like and input to the Bucom 321 via the Lucom 301.

  Similar to the first camera 10 described above, the body part of the second camera 300 includes a Bucom 321 as a control unit, a second imaging unit 316, a power supply circuit 335, a nonvolatile memory 328 as a storage unit, a coupling unit 380, and a communication unit. The communication connector 381 and the convergence angle detection mechanism 353 are provided.

  The second imaging unit 316 is for photoelectrically converting a subject image formed by the photographing lens 302 to obtain a second image, and is disposed on the image side (rear side) of the photographing lens 302. In the present embodiment, the second imaging unit 316 includes a CCD 317 and an optical low-pass filter (LPF) 318 disposed on the front side thereof. Note that the LPF 318 is appropriately disposed as necessary, and the second imaging unit 316 may be configured only by the CCD 317 that is an imaging element.

  In addition, the second camera 300 in this embodiment includes a CCD interface circuit 322 connected to the CCD 117, an image processing controller 326 that performs image processing using an SDRAM 324, a Flash ROM 325, and the like that function as a storage area, and provides an electronic imaging function. It is configured to be able to. Image data obtained by photographing with the second imaging unit 316 is sent to the first camera 10 via a communication connector 381 described later.

  The second camera 300 is provided with a non-volatile memory 328 that stores predetermined control parameters necessary for camera control, for example, a storage unit made of an EEPROM, and is accessible from the Bucom 321. As will be described in detail later, the nonvolatile memory 328 stores shape information and the like of the second camera 300 necessary for obtaining the base line length and the convergence angle of the stereoscopic image.

  Further, the second camera 300 is provided with a power supply circuit 135 that distributes the power supplied from the first camera 10 to the circuit units constituting the second camera 300 via a communication connector 381 described later. .

  Note that the second camera 300 does not have a display function and an operation function that the first camera 10 has. In the present embodiment, these functions are realized on the first camera 10 side by communication via the communication connector 381. That is, the operation of the second camera 300 in a state where the second camera 300 and the first camera 10 are coupled is performed using the camera operation SW 131 and the liquid crystal monitor 123 provided in the first camera 10.

  In the present embodiment, the second camera 300 does not include a battery and a recording medium, but the second camera 300 may be configured to include these independently of the first camera 10. Conversely, the configuration in which the functions of the circuits of the first camera 10 such as the Bucom 321, the Lucom 301, and the image processing controller 326 are duplicated in the first camera 10 side and not arranged in the second camera 300. There may be.

  The coupling unit 380 has a configuration that mechanically couples with the coupling unit 180 provided in the first camera 10. Specifically, the first camera 10 and the second camera 300 are mechanically coupled by engaging with the accessory shoe.

  The coupling unit 380 is provided with a communication connector 381 that forms a communication unit for performing communication between the first camera 10 and the second camera 300. The communication connector 381 is configured to engage with a communication connector 181 provided on the first camera 10 and to electrically connect the first camera 10 and the second camera 300. By electrically connecting the first camera 10 and the second camera 300, communication between the first camera 10 and the second camera 300 and power supply from the first camera 10 to the second camera 300 are possible. It becomes.

  In the present embodiment, the angle formed by the optical axis O1 of the first camera 10 and the optical axis O2 of the second camera 300, that is, the convergence angle α can be changed. As shown in FIGS. 1 and 5, when the second camera 300 is mechanically coupled to the first camera 10, the second camera 300 passes through the center of the image of the CCD 317 and is around the R axis parallel to the X axis. Is rotatably supported.

  Specifically, the second camera 300 is supported by a pair of support arms 383 extending from the coupling portion 380 in a fork shape so as to be rotatable around the R axis. The rotation of the second camera 300 around the R axis can be positioned and fixed at an arbitrary position by tightening a screw 381 provided at the end of the rotation shaft. The second camera 300 may be configured to be driven around the R axis by an actuator such as an electric motor.

  The second camera 300 is provided with a convergence angle detection mechanism 353 that detects the convergence angle α. The configuration of the convergence angle detection mechanism 353 is not particularly limited as long as the rotation position around the R axis of the second camera 300 can be detected, but a magnetic scale, a rotary encoder used, or an optical rotary encoder It is possible to use a rotary potentiometer using a variable resistor.

  The second camera 300 is supported by a support arm 383 so that the CCD 317 is separated from the CCD 117 by a predetermined distance D in the Y-axis direction when mechanically coupled to the first camera 10.

  Specifically, as shown in FIG. 5, the image center positions (intersections of the optical axis of the photographing lens and the light receiving surface) C1 and C2 of the CCD 317 and the CCD 117 which are the imaging elements of the second camera 300 and the first camera 10 are The second camera 300 is fixed with respect to the first camera 10 so that the X-axis coordinate and the Z-axis coordinate coincide with each other and are separated by a predetermined distance D only in the Y-axis direction. Hereinafter, an interval between the image center positions of the CCD 317 and the CCD 117 (a distance between C1 and C2 in FIG. 5) is referred to as a center position interval D.

  Here, the intermediate member 400 is provided with a coupling portion 401 that can be mechanically coupled to the coupling portion 180 provided in the first camera 10 at one end, and the coupling portion 380 of the second camera 300 at the other end. And a connecting portion 403 that can be mechanically connected to the member. That is, one end of the intermediate member 400 has a shape equivalent to that of the coupling portion 380 of the second camera 300, and the other end of the intermediate member 400 has a shape equivalent to that of the coupling portion 180 of the first camera 10. Accordingly, the first camera 10 and the second camera 300 can be mechanically coupled with the intermediate member 400 disposed therebetween.

  The connecting portion 401 of the intermediate member 400 is provided with a communication connector 402 that engages with the communication connector 181 of the first camera 10. The connecting portion 403 is engaged with the communication connector 381 of the second camera 300. A communication connector 404 is provided. The communication connectors 402 and 404 of the intermediate member 400 are electrically connected. Thus, when the first camera 10 and the second camera 300 are mechanically coupled with the intermediate member 400 disposed therebetween, the first camera 10 and the second camera 300 can be electrically connected. it can.

  As described above, the intermediate member 400 has a role as a so-called spacer that is disposed between the first camera 10 and the second camera 300 to change the distance between the two.

  Further, the intermediate member 400 is provided with a nonvolatile memory 405 that is a storage unit made of, for example, an EEPROM. The nonvolatile memory 405 is provided so as to be able to communicate with the Bucom 201 of the first camera 10 in a state where the intermediate member 400 is mechanically coupled to the first camera 10. The nonvolatile memory 405 stores shape information of the intermediate member 400, which will be described in detail later. Further, the Bucom 201 recognizes that the intermediate member 400 is coupled to the coupling unit 180 of the first camera 10 when communication with the nonvolatile memory 405 is possible.

  The same applies to the case where the intermediate member 400 is disposed therebetween. That is, when the intermediate member 400 is disposed therebetween and the first camera 10 and the second camera 300 are mechanically coupled, the value of the center position interval D increases by the size of the intermediate member 400.

  The nonvolatile memory 128 of the first camera 10 stores a Y-direction interval D1 between the coupling unit 180 and the image center position C1 of the CCD 117. Further, the non-volatile memory 328 of the second camera 300 stores a Y-direction interval D2 between the coupling unit 380 and the image center position C2 of the CCD 317. Further, the non-volatile memory 405 of the intermediate member 400 stores the Y-direction interval D3 between the coupling portion 401 and the coupling portion 403.

  In the present embodiment, the Bucom 201 acquires the values of D1, D2, and D3 via the communication unit, and calculates the center position interval D of the CCD 317 and the CCD 117 based on these values. For example, when the first camera 10 and the second camera 300 are mechanically coupled without the intermediate member 400, D = D1 + D2. Further, for example, when the first camera 10 and the second camera 300 are mechanically coupled via the intermediate member 400, D = D1 + D2 + D3.

  In other words, the coupling unit in the camera system 1 of the present embodiment can change the center position interval D of the CCD 317 and the CCD 117 while enabling communication between the first camera 10 and the second camera 300. It is configured. In the camera system 1 of the present embodiment, information that can calculate the center position interval D between the CCD 317 and the CCD 117 is stored in the storage unit.

  In the camera system 1 of the present embodiment having the above-described configuration, the Bucom 201 that is the control unit of the first camera 10 is stored in the nonvolatile memory 128 and information on the focal length and the focusing distance of the photographing lens 202. Get the value of D1. The Bucom 201 is detected by the information on the focal length and the focusing distance of the photographing lens 302 of the second camera 30, the value of D2 stored in the nonvolatile memory 328, and the convergence angle detection mechanism 353 via the communication unit. Get the value of the convergence angle α. If the Bucom 201 determines that the intermediate member 400 is coupled to the first camera 10, the Bucom 201 acquires the value of D3 stored in the nonvolatile memory 405 of the intermediate member 400 via the communication unit.

  Based on these pieces of information, Bucom 201 calculates a baseline length BL. As shown in FIG. 5, the base line length BL is obtained from the equation BL = D−N · sin α using, for example, the contact distance N from the elephant surface of the photographing lens 302 to the node. That is, the center position interval D between the CCD 317 and the CCD 117 is a value for calculating the baseline length BL. The value of the baseline length BL is used when capturing a stereoscopic image (details will be described later).

  Here, taking a stereoscopic image using the camera system 1 of the first embodiment will be described in more detail with reference to FIGS. FIG. 6 is a top view showing the arrangement of the subject and the camera system 1. FIG. 7 is a diagram showing the relationship between the subject distance and the parallax angle when a human views with both eyes. FIG. 8 shows the amount of parallax in the object scene when the subject distance corresponds to the parallax angle shown in FIG. 7 (assuming the distance for observing a stereoscopic image is 3 m) on the image field side at each subject distance. Is converted at a nodal distance of 50 mm (approximately equal to the focal length). The eye widths 65 mm and 70 mm in FIG. 7 correspond to the baseline length BL in FIG. FIG. 9 is a diagram illustrating the relationship between the imaging element interval D and the parallax amount of the camera system 1. The object distance is set to 3 m, and the nodal distance (substantially the same as the focal distance) is shown as 50 mm, 100 mm, and 150 mm.

  As shown in FIG. 6, the parallax angle with respect to the reference subject points On and Of is a subject point on the optical axis O1 of the photographing lens 202 in the first camera 10 on a plurality of two-dimensional images that are the basis of the stereoscopic image. Since there is On and Of, it becomes zero degree. On the other hand, in the second camera 300, if the optical node of the photographing lens 303 is NW2 with respect to the light rays from the subject points On and Of, the angle with respect to the optical axis of the photographing lens does not change, so θW in FIG. 6 becomes the parallax angle. . The distance fW from the center point C2 of the image sensor to the node NW2 is unique data of the photographing lens of the second camera 300, and is uniquely determined by the focal length of the photographing lens and the distance to the subject. The distance to the subject can be obtained from the focus lens position when the above-described automatic focus is achieved.

  On the other hand, FIG. 7 shows the relationship between the parallax angle generated by the human eye and the subject distance. Here, the calculation is performed assuming that the focal distance of the eyes is 16.68 mm, the eye widths are 65 mm and 70 mm, and the subject causing the parallax is 1.1 times as long as the subject at the subject distance. Since a human eye is between 65 mm and 70 mm, it is most natural to generate a stereoscopic image from an image that obtains a parallax angle as shown in FIG. 7 with respect to the distance of the subject as described above. Will give.

  When a two-dimensional image for obtaining a stereoscopic image at a distance of 3 m is displayed as a more specific image, the amount of parallax in the object scene corresponding to the parallax angle in FIG. 7 is set to a nodal distance of 50 mm (approximately a focal length of 50 mm). FIG. 8 shows a case where the parallax amount on the image field side is obtained when the image is formed by a corresponding lens. The parallax amount is also a hyperbolic graph similar to FIG.

  Further, from FIG. 7, when the main subject distance is far away, the parallax angle is small, and the parallax angle that can be discerned by the human eye is about 1 minute (visual acuity is 1.0). When the main subject at a distance is viewed with the naked eye, the stereoscopic effect of a subject away from the main subject by about 10% or more of the distance is lost.

  With respect to such a problem, in the system camera 1 of the present embodiment, when the subject is far away and the parallax angle disappears, the intermediate position 400 is used to change the center position interval D and the shooting is performed. By adjusting the focal length of the lens and the shooting screen size, the parallax angle is automatically adjusted to be in the vicinity of 2 to 3 m in FIG. As a result, in the present embodiment, a stereoscopic image having a stereoscopic effect can be taken even if the subject is far away.

  FIG. 9 shows the distance D between the nodal distance of the photographing lens (subject distance is set to 3 m, which is almost the same as the focal length of the photographing lens) and the amount of parallax on the image plane when photographing with two cameras having the same photographing range of the same image sensor. The relationship is shown. Also shown is a case where the distance (node distance) fW from the center of the image sensor to the nodal point of the taking lens is changed as a parameter capable of changing the amount of parallax. Here, the distance of the subject farther from the main subject is set to 1.1 times the distance of the main subject (10% farther). In order to obtain the same amount of parallax as the parallax angle when Ln is 3 m, it is understood that the nodal distance fW (focal length) and the camera interval D may be adjusted. As shown in FIG. 9, the amount of parallax changes in proportion to the nodal distance fW and the interval D. That is, in order to obtain an appropriate amount of parallax, not only the nodal distance fW (focal length of the photographing lens) but also the camera distance D (in FIG. 6, the distance between the image sensors is directly related to the amount of parallax. There is a need to adjust the node spacing (which can be calculated from the imaging element spacing D). Note that when the parallax amount is adjusted with the nodal distance fW, the angle of view of the image to be captured changes, but the angle of view does not change when the imaging element interval D is adjusted.

  In the present embodiment, the second camera 300 can be easily attached to and detached from the first camera 10, and the intermediate member 400 can be easily attached and detached. Therefore, it is possible to change the baseline length BL and obtain two two-dimensional images having an appropriate amount of parallax with an easy operation.

  In the present embodiment, the second camera 300 stores information on the distance D2, and the first camera 10 and the second camera 300 can communicate with each other. For this reason, even when the second camera 300 is replaced, it is possible to automatically calculate the image sensor interval D and determine whether or not the camera is in a state where an appropriate amount of parallax can be obtained.

  In the stereoscopic image, the viewing angle determined by the optical magnification of the photographing lens 203 of the first camera 10 and the size of the CCD 117, and the viewing angle determined by the optical magnification of the photographing lens 303 of the second camera 300 and the size of the image sensor 317. Although it is necessary to make them the same, since these pieces of information are also stored as camera-specific information in each camera, it is automatically determined whether or not the camera system 1 is in an appropriate state for taking a stereoscopic image. be able to. The optical magnification of the photographic lens can be adjusted by adjusting the focal length.

  In order to explain the above-described features in detail, a specific control operation of the control performed by the Bucom 201 will be described with reference to FIG. FIG. 10 is a flowchart showing the operation of the first camera 10 of this embodiment. These operations are controlled by the Bucom 201.

  The control program according to the flowchart shown in FIG. 10 that can be operated by the Bucom 201 starts its operation when the power SW (not shown) of the camera body unit 100 is turned on.

  First, a process for starting the first camera 10 is executed (step S100). That is, the power supply circuit 135 is controlled to supply power to each circuit unit constituting the first camera 10. Also, initial setting of each circuit is performed. The initialization operation of the lens unit 200 attached to the first camera 10 is also performed.

  In step S100, the focal length of each photographing lens necessary for calculating the parallax amount at the subject distance of 3 m (the node distance of 50 mm in FIG. 7) (the node distance can be calculated together with the amount of extension of the focus lens), the convergence angle α Is read into the Bucom 201 of the first camera 10.

  Next, in step S101, it is determined whether or not the stereoscopic image shooting mode is selected by the user. When the stereoscopic image capturing mode is not selected, a normal two-dimensional image capturing operation is executed. A normal two-dimensional image capturing operation is well known and will not be described.

  On the other hand, if the stereoscopic image shooting mode is selected, the process proceeds to step S102. In step S102, the detection operation of the second camera 300 and the intermediate member 400, which are accessories, is executed. In step S103, it is determined whether or not the second camera 300 necessary for capturing a stereoscopic image is attached. If the second camera 300 is not attached, the process proceeds to step S104, and a warning display for prompting the user to attach the second camera 300 is displayed on the liquid crystal monitor 123 or the like.

  On the other hand, when the second camera 300 is attached, the convergence angle α is adjusted according to the subject in step S105. Here, the images captured by the first camera 10 and the second camera 300 are superimposed on the liquid crystal monitor 123 and displayed. The user rotates the second camera 300 around the axis R so that the main subject appears in the two images, and tightens the screw 381 to fix the convergence angle α. The convergence angle α detected in this state is sent to the Bucom 301 and then transmitted to the Bucom 201 via the transmitter.

  Next, in step S106, the Bucom 201 determines the amount of parallax at the subject distance 3m from the values of D1, D2, and D3, the nodal distance fW calculated from the focal length and the focusing distance of each photographing lens, and the convergence angle α. Is calculated.

  In step S107, it is determined whether or not the parallax amount is within a preset parallax amount range (for example, a parallax amount in a range of a base length of 59 mm to 70 mm at a node distance of 50 mm in FIG. 7). If the calculated parallax amount is within the set parallax amount range, the first imaging unit 116 of the first camera 10 and the second imaging unit 316 of the second camera 300 capture a two-dimensional image. The pair of captured images are linked and recorded on the recording medium 127.

  On the other hand, when the parallax amount calculated in step S107 is outside the set parallax amount range, the process proceeds to step S108. In step S108, it is determined whether the parallax amount falls within the set parallax amount range by changing the nodal distance (the focal length that is actually changed) of the photographing lens.

  If it is determined in step S108 that the parallax amount can be set within the set parallax amount range by adjusting the nodal point of the photographic lens, the process proceeds to step S109, the focal length of the photographic lens is set to that value, and the process returns to step S106.

  On the other hand, if it is not possible to set the parallax amount within the set parallax amount range by adjusting the nodal point of the photographing lens in the determination in step S108, the process proceeds to step S110 and the parallax amount is set by exchanging the photographing lens. Judge whether it can be set to the amount range.

  If it is determined in step S110 that the parallax amount can be set within the set parallax amount range by exchanging the photographic lens, the process proceeds to step S111, and the focal length value to be exchanged is displayed on the liquid crystal monitor 123 to the user. Notice.

  If it is determined in step S110 that the parallax amount cannot be set within the set parallax amount range even after the taking lens is replaced, the process proceeds to step S112, and the parallax amount is set or set by attaching or removing the intermediate member 400. Judge whether it can be set.

  In step S112, when the parallax amount can be set within the set parallax amount range by detaching the intermediate member 400, the process proceeds to step S113, and the value of D3 of the intermediate member 400 to be attached or the intermediate member 400 should be removed. A warning is displayed on the liquid crystal monitor 123 to notify the user.

  On the other hand, if the amount of parallax cannot be set within the set parallax amount range even when the intermediate member 400 is attached or detached in step S112, the process proceeds to step S114, and a warning display such as “3D shooting impossible” is displayed on the liquid crystal monitor 123. Display to the user and notify the user.

  Furthermore, recommendation information of another accessory may be displayed. Further, the liquid crystal monitor 123 may be configured to display a stereoscopic image so that the stereoscopic effect can be confirmed visually. In the present invention, it is possible to easily select an accessory to be used at the time of shooting a stereoscopic image, adjust the convergence angle, and the like. By these adjustments, stereoscopic image shooting corresponding to subjects under various conditions from a close subject to a far subject can be performed. A system can be provided.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. A camera system is also included in the technical scope of the present invention.

  The present invention is not limited to the form of the digital camera described in the above-described embodiment, but is an electronic device such as a recording device, a mobile phone, a PDA, a personal computer, a game machine, a digital media player, a television, a GPS, a clock, etc. It can also be applied to equipment.

1 camera system,
10 First camera,
100 camera body,
101 microcomputer for body control (control unit, identification unit, calculation unit),
116 first imaging unit;
117 CCD,
128 non-volatile memory (storage unit),
135 power supply circuit,
180 joints,
181 communication connector (communication unit),
200 lens unit,
201 a lens control microcomputer;
202 photographic lens,
300 Second camera,
302 photographic lens,
316 second imaging unit,
317 CCD,
321 microcomputer for body control,
328 nonvolatile memory (storage unit),
335 power circuit,
353 convergence angle detection mechanism,
380 joint,
381 communication connector (communication unit),
400 intermediate member,
401 coupling part,
402 communication connector (communication unit),
403 coupling part,
404 communication connector,
405 Nonvolatile memory (storage unit).

Claims (6)

A first imaging lens that forms an optical image of the subject; and a first imaging unit that has a first imaging element disposed at an imaging position of the first imaging lens and generates an image of the subject. A first camera to
A second photographic lens that is detachable from the first camera via a coupling portion and forms an optical image of the subject, and is disposed at an imaging position of the second photographic lens, and the size of the light receiving surface is A second imaging unit having a second imaging element different from the first imaging element and generating an image of the subject; an optical axis of the first imaging lens; and an optical axis of the second imaging lens A second camera comprising a mechanism for adjusting the angle formed by
A detection unit for detecting the angle,
On the basis of the nodal distance from the image plane to the nodes of the second imaging lens, the angle and the first camera or recording to have the location information of the second camera, said the nodes of the first imaging lens first The camera system which has a calculation part which calculates the relative position of the node of 2 taking lenses.   The relative position is based on the position information up to the coupling unit based on the center of the first imaging unit stored in the first camera and the center of the second imaging unit stored in the second camera. The camera system according to claim 1, wherein the camera system is calculated based on position information up to the coupling unit.   The second camera is attached to the first camera via an intermediate member, and the intermediate member records positional information between the connecting portion of the intermediate member with the first camera and the connecting portion with the second camera. The camera system according to claim 2, wherein: A subject distance is calculated from an in-focus distance of the first photographing lens;
4. The camera system according to claim 3, wherein it is determined whether or not a parallax amount obtained at the relative position and the subject distance is within a predetermined range. The first photographing lens and the second photographing lens are configured such that a focal length is variable by an actuator,
When it is determined that the parallax amount is outside the predetermined range, the parallax amount is a value within the predetermined range by changing a focal length of the first photographing lens and the second photographing lens. In the case where it is determined that it is possible, the first photographing lens and the second lens so that the parallax amount falls within the predetermined range. The camera system according to claim 4, wherein the focal length of the photographing lens is changed. When it is determined that the parallax amount is outside the predetermined range, it is determined whether the parallax amount can be set to a value within the predetermined range by attaching or removing the intermediate member. Then, when it is determined that the parallax amount can be set to a value within the predetermined range by mounting or removing the intermediate member, a message to that effect is displayed. 5. The camera system according to 5.

Images