JP2007116271A - Finder unit and digital camera and method for correcting parallax - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress parallax of an optical real image system finder for use in a digital camera. <P>SOLUTION: A finder unit 6 is fixed to a digital camera through a fixing portion 32. The finder unit 6 is provided with a finder optical system 35 through which a photographer observes an object optically. An optical system 38 for finder image photographs an object image in a range substantially equivalent to the observation range of the finder optical system 35 and acquires a finder image. A common part extraction circuit 97 extracts a common part indicating the same part of a photographed object, respectively, from an image photographed by the digital camera and a finder image and then calculates the coordinate of each common part on each image. A finder control section 90 adjusts the orientation of the optical axis of each optical system 35, 38 such that the coordinate of common part of the finder image match the coordinate of common part of the photograph image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a finder device provided with a finder optical system for optically observing a subject image, a digital camera using the finder device, and a parallax correction method used for them.

In recent years, a digital camera that captures a subject image with an image sensor such as a CCD image sensor, converts the image into digital image data, and records the digital image data on a storage medium such as a built-in memory or a memory card has become widespread (see Patent Document 1). Many of these digital cameras display a captured image on an LCD provided on the back surface or an electronic viewfinder called EVF (Electronic View Finder) to frame the subject. In the method of displaying on the LCD or EVF, since the captured image itself is displayed, there is an advantage that a so-called parallax-free image can be seen and framing can be performed with a viewing rate of almost 100%.
JP 2005-260879 A

  However, LCDs and EVFs have a disadvantage that they are not suitable for shooting moving subjects such as sports shooting because a slight time lag occurs before display. In addition, with a single-lens reflex finder, you can see real-time and parallax-free images, but the space in the mirror room that divides the subject image is large and the camera becomes large. However, when a lens with a large F value is used, the viewfinder becomes dark.

  On the other hand, in an optical real image finder (hereinafter referred to as OVF: Optical View Finder) that uses an optical system different from the optical system for photographing, parallax occurs, but a real-time image can be seen. However, since it is a separate optical system, there are many advantages such as the problem included in the single-lens reflex system does not occur, and the appearance of OVF that does not generate parallax has been desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress parallax in an OVF used for a digital camera.

  In order to achieve the above object, a finder apparatus of the present invention that is detachably attached to a digital camera that captures a subject image and obtains a captured image includes a finder optical system that optically observes the subject image, and the finder optical system. A finder main body provided with an image acquisition optical system that captures the subject image in a range substantially equivalent to the observation range of the system and acquires a finder image; and rotating or moving the finder main body of the finder optical system An optical axis adjustment mechanism for directing the optical axis in an arbitrary direction, a mounted portion that detachably attaches the finder body and the optical axis adjustment mechanism to an attachment portion provided in the digital camera, and the photographing from the digital camera A communication means for receiving an image, and the same portion of the subject image from each of the captured image and the viewfinder image A common part extracting means for extracting a common part and calculating coordinates on each image of each common part; and the common part extracted from the finder image to the coordinates of the common part extracted from the photographed image And a control means for driving the optical axis adjustment mechanism so as to match the coordinates of the part.

  The finder optical system includes an objective lens and an eyepiece lens, and the image acquisition optical system includes a photographic lens disposed in the vicinity of the objective lens, and the subject image formed by the photographic lens. It is preferable that it is comprised from the image pick-up element which image | photographs and acquires the said finder image.

  The image acquisition optical system is disposed between the objective lens and the eyepiece lens, and splits the subject image transmitted through the objective lens into two, and the half mirror splits the image. You may comprise from the relay lens which forms one said to-be-photographed image, and the image pick-up element which image | photographs the said to-be-photographed image by this relay lens, and acquires the said finder image.

  Further, the finder optical system has a variable magnification lens movable in the optical axis direction between the objective lens and the eyepiece lens, and moves the finder optical system by moving at least the variable magnification lens in the optical axis direction. It is preferable to provide a scaling unit for changing the zoom magnification of the system.

  The control unit causes the common part extraction unit to extract the two common parts from each of the captured image and the viewfinder image, and calculates the width of each extracted common part for each image. Driving the scaling unit so that the ratio between the calculated width of each common part and the width of each image is approximated between the images, thereby obtaining the viewfinder image at the angle of view of the captured image. It is preferable to match the angle of view.

  The digital camera of the present invention that captures a subject image and obtains the photographed image includes a finder optical system for optically observing the subject image, and the subject image in a range substantially equivalent to the observation range of the finder optical system. A finder main body provided with an image acquisition optical system for taking a finder image and acquiring a finder image, and an optical axis adjustment mechanism for rotating or moving the finder main body to direct the optical axis of the finder optical system in an arbitrary direction A common portion that indicates the same portion of the subject image from each of the captured image and the viewfinder image, an attachment portion to which the viewfinder device is detachably attached, a communication means for receiving the viewfinder image from the viewfinder device, A common part extracting means for calculating the coordinates of each common part on each image, and a pre-extracted from the photographed image The coordinates of the common region, and wherein the and a control means for driving the optical axis adjustment mechanism to match the coordinates of said common portion is extracted from the viewfinder image.

  Further, the parallax correction method of the present invention acquires the finder image by capturing the subject image in a range substantially equivalent to the observation range of the finder optical system for optically observing the subject image, and acquires the photographic image and the finder. Extracting a common part indicating the same part of the subject image from each of the images, calculating coordinates on each image of each common part, the coordinates of the common part extracted from the captured image, The direction of the optical axis of the finder optical system is changed so that the coordinates of the common part extracted from the finder image are matched.

  In the present invention, a finder image is acquired by an image acquisition optical system that captures a subject image in a range substantially equivalent to the observation range of the finder optical system, and a common portion showing the same portion of the subject image from each of the captured image and the finder image Extract the part, calculate the coordinates of each common part on each image, and match the coordinates of the common part extracted from the finder image with the coordinates of the common part extracted from the captured image. The direction of the optical axis was changed. As a result, the parallax is corrected, so that a real-time and parallax-free image can be seen, and the camera is enlarged due to the mirror room as in the single-lens reflex system, or an image corresponding to the F-number of the photographing lens. Does not get dark.

  FIG. 1 is a perspective view schematically showing the configuration of the camera system 2. The camera system 2 includes a digital camera 4 including a camera body 10 and a lens unit 11 and a finder unit (finder device) 6 that is detachably attached to the digital camera 4 as an accessory. The lens unit 11 has a photographic image optical system 12 including a photographic lens 13 exposed on the front surface and a CCD 14 that photoelectrically converts a subject image formed by the photographic lens 13. The camera body 10 detachably holds the lens unit 11 and sends and receives various control signals to drive the CCD 14 and the like, thereby acquiring digital image data corresponding to the subject image.

  A plurality of types of lens units 11 are prepared in advance, for example, those with different focal lengths of the taking lens 13, those with different numbers of pixels of the CCD 14, those capable of monochrome photography, and those capable of infrared photography. The digital camera 4 can easily obtain image data corresponding to the shooting situation by selectively mounting each lens unit 11 on the camera body 10.

  On the back surface of the lens unit 11, a mount portion 15 in which a bayonet claw 16 is formed is provided. On the other hand, a mount 18 having a bayonet groove 19 is provided on the front surface of the camera body 10 facing the mount 15. The mount portions 15 and 18 are fitted to each other by pushing the bayonet pawl 16 into alignment with the bayonet groove 19 and rotating it clockwise. Further, the bayonet claw 16 is provided with a plurality of contacts 16a. Each contact 16a comes into contact with a contact (not shown) provided in the bayonet groove 19 when the bayonet claw 16 and the bayonet groove 19 are fitted. Thereby, each mount part 15 and 18 mechanically connects the camera main body 10 and the lens unit 11 by the bayonet nail | claw 16 and the bayonet groove | channel 19, and electrically connects the camera main body 10 and the lens unit 11 by each contact. Also connect to.

  The mount portion 18 is provided with a lock pin 20 and a mount lid 21. When the lens unit 11 is mounted on the camera body 10, the lock pin 20 engages with a pin hole (not shown) formed in the mount portion 15 to restrict the rotation of the lens unit 11. Is prevented from falling off the camera body 10. The mount lid 21 is spring-biased toward the front surface, and closes the opening into which the bayonet claw 16 enters when the lens unit 11 is not attached, and prevents dust and the like from entering the camera body 10. .

  On the front surface of the camera body 10, in addition to the mount portion 18, a lock release button 22 for releasing the engagement of the lock pin 20 and a strobe light emitting portion 24 for irradiating a subject in accordance with execution of shooting are provided. When the lock release button 22 is pressed, the lock pin 20 is retracted into the camera body 10 in conjunction with this operation, and the engagement between the lock pin 20 and the pin hole is released. Thereby, the rotation of the lens unit 11 is allowed again, and the lens unit 11 can be detached from the camera body 10.

  On the upper surface of the camera body 10, a release button 25 for instructing the digital camera 4 to perform shooting, and a mode switching dial for switching between a shooting mode for shooting a still image and a playback mode for playing back and displaying the shot image. 26, and an accessory shoe (attachment portion) 28 for attaching the accessory part detachably. The release button 25 is a two-stage push switch. When the release button 25 is lightly pressed (half-pressed), various shooting preparation processes such as automatic exposure adjustment (AE) and automatic focus adjustment (AF) are started. In this state, when the release button 25 is strongly pressed once again (fully pressed), the imaging signal for one screen subjected to the imaging preparation process is converted into image data.

  The finder unit 6, which is an external OVF, is composed of a finder main body 30, a rotation mechanism part (optical axis adjustment mechanism) 31, and a mounted part 32. The finder main body 30 is provided with a finder optical system 35 including an objective lens 33 exposed on the front surface and an eyepiece lens 34 exposed on the back surface. The photographer can perform framing while observing a real-time subject image by looking into the eyepiece lens 34. The finder main body 30 is provided with a finder image optical system (image acquisition optical system) 38 including a photographing lens 36 and a CCD (imaging device) 37. The finder image optical system 38 is aligned with the direction of the optical axis of the finder optical system 35, and obtains a finder image by photographing a subject image in a range substantially equivalent to the observation range of the finder optical system 35. This finder image is used when correcting the parallax between the photographic image optical system 12 and the finder optical system 35.

  The rotation mechanism 31 is connected to the viewfinder main body 30 via the shaft 40 and is connected to the attached portion 32 via the shaft 41. The rotation mechanism unit 31 is provided with a known rotation mechanism including a motor, a gear, and the like. The rotation mechanism unit 31 rotates in the θ direction about the shaft 41 and rotates the finder body 30 in the γ direction about the shaft 40. The directions of the optical axes of the finder optical system 35 and the finder image optical system 38 are adjusted.

  The attached portion 32 is formed so as to be fitted to the accessory shoe 28 and is fixed to the accessory shoe 28 by being inserted so as to slide forward from the rear of the camera body 10. Further, the accessory shoe 28 and the attachment portion 32 have a plurality of contacts that come into contact with each other by attachment. Thereby, the accessory shoe 28 and the attached portion 32 connect the digital camera 4 and the finder unit 6 mechanically as well as electrically.

  FIG. 2 is a block diagram schematically showing the internal configuration of the digital camera 4. The camera main body 10 is provided with a main body control unit (control means) 50 for comprehensively controlling each unit in the main body. The main body control unit 50 includes a ROM that stores a control program for controlling each unit and a RAM that temporarily stores work data. The main body control unit 50 controls each unit based on this control program.

  A memory 53 is connected to the digital signal processing unit 51 via a system bus 52. When the image data acquired from the lens unit 11 is temporarily stored in the memory 53, the digital signal processing unit 51 performs various kinds of images such as gradation conversion, white balance correction, and gamma correction on the image data. Processing, YC conversion processing, and the like are performed.

  Connected to the system bus 52 are a serial driver 54 for communicating with the lens unit 11, a serial driver (communication means) 55 for communicating with the finder unit 6, a strobe controller 56, an LCD driver 57, a media controller 58, and the like. Has been. The serial driver 54 is connected to the lens unit 11 via each contact provided on each mount portion 15, 18. The serial driver 54 is configured to be capable of bidirectional communication, and transmits and receives various control signals and image data to and from the lens unit 11. Similarly, the serial driver 55 is connected to the finder unit 6 via each contact provided on the accessory shoe 28 and the attached portion 32, and transmits and receives various control signals and image data.

  The strobe control circuit 56 causes the strobe light emitting unit 24 to emit light according to the strobe light emission signal transmitted from the main body control unit 50. The LCD driver 57 converts the input image data into an analog composite signal, for example, and displays it on the LCD 59 provided on the back surface of the camera body 10. Thereby, a photographed image, various menu screens, and the like are displayed on the LCD 59. Further, the LCD 59 displays the image data for the through image transferred from the lens unit 11 when the finder unit 6 is not attached to the digital camera 4. On the other hand, when the finder unit 6 is attached, the image data for the through image is sent to the finder unit 6 via the serial driver 55, and is compared with the finder image as a photographed image by the photographed image optical system 12. Used. At this time, the image data for the through image may be transferred to the finder unit 6 and displayed on the LCD 59.

  The media controller 58 reads and writes image data and the like with respect to the recording medium 60 detachably loaded in the camera body 10. When the digital camera 4 is in the shooting mode, the image data acquired by the lens unit 11 is recorded on the recording medium 60. On the other hand, when the digital camera 4 is in the reproduction mode, the image data recorded on the recording medium 60 is reproduced and displayed on the LCD 59.

  The camera body 10 has a battery storage chamber (not shown), and a battery 62 is detachably held in the battery storage chamber. The battery 62 is connected to the power supply control unit 63 through an electrode provided in the battery storage chamber. The power control unit 63 transforms the output voltage of the battery 62 to a predetermined voltage and supplies it to each part of the camera body 10. A power switch 64 is connected to the power controller 63. Supply and stop of power to each unit is controlled in response to an ON / OFF operation of the power switch 64. The power supply control unit 63 is also connected to the mount unit 18 and the accessory shoe 28, and also supplies power to the lens unit 11 and the finder unit 6 through each contact.

  The lens unit 11 is provided with a unit control unit 70 that comprehensively controls each unit in the unit. The unit control unit 70 includes a ROM that stores a control program for controlling each unit and a RAM that temporarily stores work data. The unit controller 70 controls each part based on this control program.

  The photographing lens 13 includes a zoom lens 72, a diaphragm 73, and a focus lens 74 arranged along the optical axis. A lens motor 75 is connected to the zoom lens 72. The lens motor 75 moves the zoom lens 72 to the wide side or the tele side in conjunction with an operation of a zoom operation button (not shown). An iris motor 76 is connected to the diaphragm 73. The iris motor 76 adjusts the amount of light incident from the zoom lens 72 by changing the aperture area (aperture value) of the diaphragm 73 during the shooting preparation process when the release button 25 is half-pressed. A lens motor 77 is connected to the focus lens 74. The lens motor 77 moves the focus lens 74 to the near side or the infinity side in response to zooming of the zoom lens 72 or half-pressing of the release button 25.

  Each motor 75, 76, 77 is connected to a motor driver 78. The motor driver 78 is connected to the unit controller 70 and transmits drive pulses to the motors 75, 76, 77 based on the control signal from the unit controller 70. Each of the motors 75, 76, 77 rotationally drives the rotating shaft in accordance with this drive pulse. In addition, as each motor 75, 76, 77, a stepping motor etc. are used, for example.

  Further, the CCD 14 is connected to the unit controller 70 via a CCD driver 80. The unit controller 70 controls the CCD driver 80 to drive the CCD 14. The CCD 14 converts the subject image into an electrical signal by photoelectric conversion, and acquires image data of an analog signal.

  The CCD 14 is connected to the analog signal processing unit 81 and outputs the acquired image data to the analog signal processing unit 81. The analog signal processing unit 81 is connected to the unit control unit 70 via the system bus 82 and is controlled by the unit control unit 70. The analog signal processing unit 81 performs noise removal and amplification processing on the image data and outputs the processed image data to the A / D converter 83. The A / D converter 83 converts image data from an analog signal to a digital signal.

  An AE / AF detector 84 is connected to the A / D converter 83. The A / D converter 83 inputs the image data converted into the digital signal to the AE / AF detection unit 84. The AE / AF detection unit 84 is controlled by the unit control unit 70, detects the in-focus position where the amplitude value of the high frequency component of the image data is maximized, and outputs the AF detection value to the unit control unit 70. Further, the AE / AF detection unit 84 detects an AE detection value at which the exposure is optimal, and outputs the detected AE detection value to the unit control unit 70. The unit control unit 70 performs AF processing by moving the focus lens 74 to a position where the AF detection value becomes the highest, and controls operations of the diaphragm 73 and the CCD 14 based on the AE detection value.

  A serial driver 85 is connected to the system bus 82. The serial driver 85 is connected to the serial driver 54 of the camera body 10 via the mount parts 15 and 18. Each serial driver 54, 85 converts the parallel signal from each control unit 50, 70 into a serial signal and transmits it, converts the received signal back to a parallel signal, and inputs it to each control unit 50, 70. Thereby, transmission / reception of a control signal and image data is performed between the camera body 10 and the lens unit 11.

  The power control unit 86 is connected to the mount unit 15, and is connected to the power control unit 63 of the camera body 10 through the contacts of the mount units 15 and 18. The power controller 86 distributes the power to each part of the lens unit 11 when power is supplied from the power controller 63.

  FIG. 3 is a block diagram schematically showing the internal configuration of the finder unit 6. The finder main body 30 of the finder unit 6 is provided with a finder control unit (control means) 90 that comprehensively controls each part of the finder unit 6. The finder control unit 90 includes a ROM that stores a control program for controlling each unit, and a RAM that temporarily stores work data. The finder control unit 90 controls each unit based on this control program.

  As described above, the finder main body 30 is provided with the finder optical system 35 including the objective lens 33 and the eyepiece 34, and the finder image optical system 38 including the photographing lens 36 and the CCD 37. The CCD 37 is connected to a finder control unit 90 via a CCD driver 91 and is driven under the control of the finder control unit 90. The drive control of the CCD 37 is timed with the CCD 14 of the captured image optical system 12. The CCD 37 converts the subject image formed by the photographing lens 36 into an electric signal, and acquires image data of an analog signal.

  The CCD 37 is connected to the analog signal processing unit 92 and outputs the acquired image data to the analog signal processing unit 92. The analog signal processing unit 92 is connected to the finder control unit 90 via the system bus 93 and is controlled by the finder control unit 90. The analog signal processing unit 92 performs noise removal and amplification processing on the image data and outputs the image data to the A / D converter 94. The A / D converter 94 converts image data from an analog signal to a digital signal.

  A digital signal processing unit 95 is connected to the A / D converter 94. The A / D converter 94 inputs the image data converted into the digital signal to the digital signal processing unit 95. The digital signal processing unit 95 performs various image processing such as gradation conversion, white balance correction, and gamma correction on the image data input from the A / D converter 94, YC conversion processing, and the like, and performs optical imaging. The state is the same as the image data captured by the system 12. The image data that has been subjected to various processes is temporarily stored as a finder image in, for example, a RAM provided in the finder control unit 90.

  In addition, a serial driver (communication means) 96 and a common part extraction circuit (common part extraction means) 97 are connected to the system bus 93. The serial driver 96 is connected to the serial driver 55 of the camera body 10 via the accessory shoe 28 and the attached portion 32. Each serial driver 55, 96 converts a parallel signal from each control unit 50, 90 into a serial signal and transmits it, converts the received signal back to a parallel signal, and inputs it to each control unit 50, 90. Thereby, transmission and reception of a control signal and image data are performed between the camera body 10 and the finder unit 6.

  The common part extraction circuit 97 uses the same image of the subject captured from each of the photographed image transferred from the camera body 10 via the serial drivers 55 and 96 and the finder image temporarily stored in the finder controller 90. The common part CP indicating the part is extracted, and the coordinates of each common part CP on each image are calculated. Of course, images taken at the same timing are used as the images from which the common part CP is extracted.

  FIG. 4 is an explanatory diagram showing an example of the extraction of the common part CP by the common part extraction circuit 97. 4A is a finder image captured by the finder image optical system 38, and FIG. 4B is a captured image captured by the captured image optical system. The common part extraction circuit 97 extracts the left eye part from each image with the left eye of the person as the common part CP, and sets the coordinates (Xa, Ya) and (Xb, Yb) is calculated. The common part extraction circuit 97 that has calculated the coordinates outputs the calculated coordinates to the finder control unit 90. Note that, as a method for extracting the common part CP, for example, a known pattern recognition technique that uses frequency characteristics, hue components, or the like may be used. In the example of FIG. 4, the coordinates are calculated with the center of each image as the origin, but the position serving as the origin is not limited to this and may be any position in each image.

  The power supply control unit 98 is connected to the attached portion 32, and is connected to the power supply control unit 63 of the camera body 10 through the contact of the accessory shoe 28 and the attached portion 32. The power supply control unit 98 distributes the power to each part of the finder unit 6 when power is supplied from the power supply control unit 63.

  The rotation mechanism unit 31 includes a rotation mechanism unit 31 and a θ direction rotation motor 100 for rotating the viewfinder main body 30 in the θ direction, a γ direction rotation motor 101 for rotating the viewfinder main body 30 in the γ direction, And a motor driver 102 for driving the motors 100 and 101 to rotate. The motor driver 102 is connected to the finder control unit 90 via the system bus 93, and rotates the motors 100 and 101 under the control of the finder control unit 90.

  Further, the finder control unit 90 that has received the coordinates of each common part CP from the common part extraction circuit 97 calculates a deviation of each coordinate, and sets the coordinates of the common part CP of the finder image to the coordinates of the common part CP of the photographed image. The motors 100 and 101 are controlled so that the optical axes of the finder optical system 35 and the finder image optical system 38 are adjusted. The deviation of each coordinate indicates a parallax, and thus the parallax correction between the captured image optical system 12 and the finder optical system 35 is performed.

  Next, the operation of the camera system 2 configured as described above will be described with reference to the flowchart shown in FIG. In order to perform shooting with the camera system 2, the lens unit 11 and the finder unit 6 are first attached to the camera body 10, and the power switch 64 provided on the camera body 10 is turned on. When the power switch 64 is turned on, the voltage of the battery 62 is transformed by the power control unit 63 and supplied to each part of the camera body 10. The power supply control unit 63 supplies power to the power supply control unit 86 of the lens unit 11 through the contacts of the mount units 15 and 18, and the finder unit 6 through the contacts of the accessory shoe 28 and the mounted portion 32. The power is supplied to the power supply control unit 98 of the system. The power control units 86 and 98 to which power is input distributes and supplies the power to the lens unit 11 and the finder unit 6. As a result, the camera system 2 is activated and becomes ready for photographing.

  When the shooting mode is set by operating the mode switching dial 26 after the camera system 2 is activated, the CCD drivers 80 and 91 are driven by the unit control unit 70 and the finder control unit 90, respectively, and the optical system for the shot image 12 and image data acquisition by the finder image optical system 38 is started. At this time, the drive timings of the CCDs 14 and 37 are matched, and the captured image and the finder image are acquired at the same timing.

  Each acquired image data is input to a common part extraction circuit 97 provided in the finder main body 30 of the finder unit 6 as a captured image and a finder image, respectively. The common part extraction circuit 97 extracts the common part CP from each input image, and calculates the coordinates (Xa, Ya) and (Xb, Yb) of each extracted common part CP (see FIG. 4). The calculated coordinates (Xa, Ya) and (Xb, Yb) are input to the finder controller 90.

  The viewfinder control unit 90 that has received the coordinates (Xa, Ya) and (Xb, Yb) first obtains the horizontal ratio Xb / Xa of each image, and this ratio falls within the range of 0.99 to 1.01. It is determined whether or not. The finder control unit 90 that has determined that the ratio in the horizontal direction is not within the numerical range described above subtracts the coordinate Xa of the finder image from the coordinate Xb of the photographed image, and calculates the deviation of Xa with respect to Xb. However, the numerical range for determining the ratio is not limited to the above, and may be set arbitrarily.

  As shown in FIG. 4, when Xa is larger than Xb (the sign of deviation is negative), the finder control unit 90 has the finder image optical system 38 and the finder optical system 35 than the captured image optical system 12. Is determined to be viewing the left side, and the θ direction rotation motor 100 is controlled so that the finder body 30 is directed rightward by the deviation. On the other hand, when Xa is smaller than Xb (the sign of the deviation is positive), the finder control unit 90 looks at the right side of the finder image optical system 38 and the finder optical system 35 relative to the captured image optical system 12. The θ direction rotation motor 100 is controlled so that the finder body 30 is directed leftward by the deviation. Accordingly, the lateral parallax between the captured image optical system 12 and the finder optical system 35 is corrected.

  The finder control unit 90 that corrects the parallax in the horizontal direction obtains the ratio Yb / Ya in the vertical direction of each image and determines whether or not this ratio is within the range of 0.99 to 1.01. The viewfinder control unit 90 that has determined that the ratio in the vertical direction does not fall within the above numerical range subtracts the coordinate Ya of the finder image from the coordinate Yb of the captured image, and calculates the deviation of Ya with respect to Yb. As shown in FIG. 4, when Ya is larger than Yb (the sign of the deviation is negative), the finder control unit 90 has the finder image optical system 38 and the finder optical system 35 than the captured image optical system 12. Is determined to look at the lower side, and the γ-direction rotating motor 101 is controlled so that the finder main body 30 is directed upward by the deviation. On the other hand, when Ya is smaller than Yb (the sign of the deviation is positive), the finder control unit 90 looks at the finder image optical system 38 and the finder optical system 35 above the captured image optical system 12. Γ direction rotation motor 101 is controlled so that finder main body 30 is directed downward by the deviation. As a result, the vertical parallax between the captured image optical system 12 and the finder optical system 35 is corrected.

  Thus, the parallax between the photographic image optical system 12 and the finder optical system 35 is corrected, so that the photographer can take a picture while looking through the eyepiece lens 34 to view a real-time and parallax-free image. be able to. In addition, unlike the single-lens reflex system, the camera is not enlarged by the mirror room, and the image is not darkened according to the F value of the photographing lens. Further, since the finder unit 6 is configured as an external OVF, the price and size of the digital camera 4 itself can be suppressed. Thereby, it is possible to meet the user's needs related to the price and size of the digital camera 4, and by adding the finder unit 6 as an accessory, it is possible to meet the user's needs related to photographing. Further, in the accessory shoe 28, it is difficult to precisely align the position, and an error occurs in the attachment position. In this example, the optical axis is adjusted by the rotation mechanism 31. Can be canceled.

  In the above-described embodiment, the rotation mechanism unit 31 having two rotation axes is shown as the optical axis adjustment mechanism. However, the optical axis adjustment mechanism is not limited to this, for example, the light of the optical system 12 for captured images. You may make it comprise with the slide movement mechanism matched on an axis | shaft, and the rotation mechanism which converges each optical axis. Further, when the finder unit 6 is attached in a state where the optical axis of the photographic image optical system 12 and the optical axis of the finder optical system 35 are aligned, only a single-axis rotation mechanism is required.

  In the above embodiment, the finder unit 6 is attached to the accessory shoe 28. However, the attachment method of the finder unit 6 is not limited to this, and for example, it may be attached via a dedicated bracket or the like. Good. Furthermore, in the above embodiment, the digital camera 4 and the finder unit 6 are electrically connected via the contacts provided on the accessory shoe 28 and the attached portion 32, but the present invention is not limited thereto. For example, it may be connected by a cable or the like. Furthermore, you may make it make both communicate by radio | wireless.

  In the above embodiment, the common part extraction circuit 97 is provided in the finder unit 6, and the finder unit 6 extracts the common part CP of each image and calculates the coordinates. However, the present invention is not limited to this. For example, as shown in FIG. 6, the camera body 10 may be provided with a common part extraction circuit (common part extraction means) 110, and the camera body 10 may extract the common part CP of each image and calculate the coordinates. . At this time, the determination of the ratio of each coordinate and the control of each motor for adjusting the orientation of the finder main body 30 may be performed by the main body control unit 50, or each coordinate is transmitted to the finder unit 6 to perform finder control. This may be performed by the unit 90.

  In the finder unit 6 of the above embodiment, the finder optical system 35 and the finder image optical system 38 are configured as separate optical systems, so that there is no parallax between the optical systems 35, 38. It will occur. In order to prevent this, the finder unit may be configured as shown in FIG. Note that the same functions and configurations as those of the above embodiment are given the same reference numerals, and detailed description thereof is omitted.

  In the finder unit 120 shown in FIG. 7, a finder optical system 123 is configured by the objective lens 121 and the eyepiece 122, and a half mirror 125, a relay lens 126, and a CCD (imaging device) disposed behind the eyepiece 122. 127 is a viewfinder image optical system (image acquisition optical system) 128. The half mirror 125 separates the light transmitted through the eyepiece lens 122 into two. The relay lens 126 forms an image of one light split by the half mirror 125 on the CCD 127. As described above, according to the finder unit 120 of the present example, the parallax between the subject image viewed by the photographer and the CCD 127 that acquires the finder image can be completely suppressed, so that the photographic image optical system 12 and the finder optical system are used. It is possible to correct the parallax generated between the first and second terminals with higher accuracy.

  Furthermore, as shown in FIG. 8, the present invention may be applied to a finder with a zoom function. In the finder unit 130 shown in FIG. 8, a finder optical system 134 is configured by the objective lens 131, the variable magnification lens 132, and the eyepiece lens 133, and a half mirror provided between the variable magnification lens 132 and the eyepiece lens 133. A viewfinder image optical system (image acquisition optical system) 140 is configured by 136, the relay lens 137, and the CCD (imaging device) 138. Pins 131 a and 132 a are projected from the objective lens 131 and the zoom lens 132. The pins 131a and 132a enter cam grooves 142a and 142b formed in a cylindrical cam (magnification changing means) 142, respectively. The cylindrical cam 142 is connected to the motor 143 via a gear or the like. The cylindrical cam 142 rotates following the rotation of the motor 143, and moves the objective lens 131 and the variable power lens 132 in the optical axis direction along the cam grooves 142a and 142b. As a result, the magnification of the finder optical system 134 is changed to the telephoto side or the wide side. The motor 143 is connected to the finder controller 90 via the motor driver 144 and the system bus 93, and the rotation is controlled by the finder controller 90.

  In the finder unit 130, before the parallax correction between the photographic image optical system 12 and the finder optical system 134 is performed, the angle of view of both is adjusted. When the captured image and the finder image are input to the common part extraction circuit 97, the finder control unit 90 causes the common part extraction circuit 97 to extract two common parts CP1 and CP2, as shown in FIG. The coordinates of the common parts CP1 and CP2 are calculated. The finder controller 90 that has caused the common part extraction circuit 97 to calculate the coordinates calculates the widths A1 and A2 of the common parts CP1 and CP2 from the images based on the coordinates. The finder control unit 90 that has calculated the widths A1 and A2 calculates the ratio between the widths A1 and A2 and the widths B1 and B2 of the respective images, so that the motor A1 and B2 are approximated to A2 and B2. 143 is driven to change the magnification of the finder optical system 134. Thereby, the field angle of the finder optical system 134 is matched with the field angle of the captured image optical system 12. The finder control unit 90, which has adjusted the angle of view between the captured image optical system 12 and the finder optical system 134, then follows the procedure shown in FIG. 5 for parameters generated between the captured image optical system 12 and the finder optical system 134. Correct the Lux.

  The OVF is usually designed so that an image viewed through the viewfinder always falls within the shooting range. For this reason, the range that can be seen with the viewfinder (hereinafter referred to as the field of view rate) is limited to about 80% of the shooting range so that errors in parallax and angle of view can be allowed. On the other hand, in the finder unit 130 of this example, the parallax and the angle of view of the photographic image optical system 12 and the finder optical system 134 are adjusted, so that the field of view can be brought close to almost 100%. . Further, by adjusting the parallax and the angle of view, the present invention can also be applied to an OVF of a long focus lens, which has been conventionally difficult.

  In each of the above-described embodiments, an example in which the finder unit is attached to the digital camera 4 including the lens unit 11 including the photographing lens 13 and the CCD 14 and the camera body 10 that detachably holds the lens unit 11 is shown. However, the digital camera to which the finder unit is attached is not limited to the above. For example, a digital camera in which a CCD is provided on the camera body side and only the photographic lens is detachable, or a compact type digital camera in which the photographic lens is also integrated. Any other type of digital camera such as a camera may be used.

It is a perspective view which shows the structure of a camera system roughly. It is a block diagram which shows the internal structure of a digital camera schematically. It is a block diagram which shows roughly the internal structure of a finder unit. It is explanatory drawing which shows an example of the extraction of a common part by a common part extraction circuit. It is a flowchart which shows the correction | amendment procedure of parallax. It is a block diagram which shows the example which provided the common site | part extraction circuit in the camera main body. It is a block diagram which shows the example which divided the finder optical system and comprised the optical system for finder images. FIG. 10 is a block diagram illustrating an example in which the present invention is applied to a zoom finder. It is explanatory drawing which shows an example of a view angle adjustment.

Explanation of symbols

2 Camera system 4 Digital camera 6 Viewfinder unit (finder device)
DESCRIPTION OF SYMBOLS 10 Camera body 11 Lens unit 12 Optical system for picked-up image 28 Accessory shoe (mounting part)
30 Finder body 31 Rotation mechanism (optical axis adjustment mechanism)
32 Mounted portion 33, 121, 131 Objective lens 34, 122, 133 Eyepiece lens 35, 123, 134 Viewfinder optical system 36 Shooting lens 37, 127, 138 CCD (imaging device)
38, 128, 140 Viewfinder image optical system (image acquisition optical system)
50 Main body control unit (control means)
55 Serial driver (communication means)
90 Finder control unit (control means)
96 Serial driver (communication means)
97, 110 Common part extraction circuit (common part extraction means)
125, 136 Half mirror 126, 137 Relay lens 132 Zoom lens 142 Cylindrical cam (magnification means)

Claims (7)

In a finder device that can be detachably attached to a digital camera that captures a subject image and obtains a captured image,
A finder optical system for optically observing the subject image, and a finder optical system for capturing the subject image in a range substantially equivalent to the observation range of the finder optical system and acquiring a finder image. The body,
An optical axis adjustment mechanism for rotating or moving the finder main body to direct the optical axis of the finder optical system in an arbitrary direction;
A mounted portion that detachably attaches the finder body and the optical axis adjusting mechanism to a mounting portion provided in the digital camera;
Communication means for receiving the captured image from the digital camera;
A common part extracting means for extracting a common part indicating the same part of the subject image from each of the captured image and the finder image, and calculating coordinates on each image of each common part;
Control means for driving the optical axis adjustment mechanism to match the coordinates of the common part extracted from the finder image with the coordinates of the common part extracted from the captured image. Finder device to do. The finder optical system is composed of an objective lens and an eyepiece lens,
The image acquisition optical system includes a photographic lens disposed in the vicinity of the objective lens, and an imaging element that captures the subject image formed by the photographic lens and acquires the finder image. The finder device according to claim 1, characterized in that: The finder optical system is composed of an objective lens and an eyepiece lens,
The image acquisition optical system is disposed between the objective lens and the eyepiece lens, and a half mirror that splits the subject image that has passed through the objective lens into two, and one of the half mirrors split by the half mirror 2. A finder apparatus according to claim 1, comprising: a relay lens that forms the subject image; and an image pickup device that captures the subject image formed by the relay lens and obtains the finder image. . The finder optical system has a variable power lens movable in the optical axis direction between the objective lens and the eyepiece lens,
4. A finder apparatus according to claim 2, further comprising a magnifying means for magnifying a zoom magnification of the finder optical system by moving at least the magnifying lens in an optical axis direction.   The control means causes the common part extraction means to extract two common parts from each of the photographed image and the finder image, calculates a width of each extracted common part for each image, and calculates By driving the zooming means so that the ratio of the width of each common part and the width of each image approximated between the images, the image of the finder image is set to the angle of view of the captured image. 5. The finder apparatus according to claim 4, wherein corners are matched. In a digital camera that takes a subject image and obtains a shot image,
A finder optical system for optically observing the subject image, and a finder optical system for capturing the subject image in a range substantially equivalent to the observation range of the finder optical system and acquiring a finder image. An attachment portion to which a finder device comprising a main body and an optical axis adjustment mechanism for rotating or moving the finder main body to direct the optical axis of the finder optical system in an arbitrary direction is detachably attached;
Communication means for receiving the viewfinder image from the viewfinder device;
A common part extracting means for extracting a common part indicating the same part of the subject image from each of the captured image and the finder image, and calculating coordinates on each image of each common part;
Control means for driving the optical axis adjustment mechanism to match the coordinates of the common part extracted from the finder image with the coordinates of the common part extracted from the captured image. Digital camera. In a parallax correction method for a finder apparatus that has a finder optical system for optically observing a subject image and is detachably attached to a digital camera that captures the subject image and obtains a captured image.
Capture the subject image in a range substantially equivalent to the observation range of the finder optical system to obtain a finder image,
Extracting a common part indicating the same part of the subject image from each of the photographed image and the finder image, calculating coordinates on each image of each common part,
The direction of the optical axis of the finder optical system is changed so that the coordinates of the common part extracted from the finder image are matched with the coordinates of the common part extracted from the photographed image. Correction method.

Images