JP4833129B2 - Digital camera and autofocus device - Google Patents

Description

  The present invention relates to a digital camera and an autofocus device that perform phase difference detection type autofocus processing.

  Digital cameras that capture a subject image with a solid-state imaging device such as a CCD image sensor and acquire digital image data are widely used. Many of these digital cameras have an autofocus function that automatically focuses on the subject. For autofocus of digital cameras, mainly a contrast detection method and a phase difference detection method are employed.

  The contrast detection method has a simple configuration and can provide an autofocus function at a low cost. However, since the focus position is searched while moving the focus lens, it takes time to focus. On the other hand, the phase difference detection method recognizes a defocus amount and a direction by detecting a shift amount (phase difference) between two images acquired from a symmetric optical path with an optical axis in between. While it is possible to focus quickly, there is a problem in that cost is increased because an image pickup device other than for photographing and an optical system for dividing the subject light are separately required.

  In order to solve the above-described problems of each method and realize an autofocus function that can obtain a low-cost and quick focus, a method for suppressing the cost increase by the phase difference detection method is disclosed in Patent Documents 1 and 2, for example. Is known.

In Patent Document 1, two AF openings formed symmetrically with an optical axis in addition to a normal aperture opening are provided, and each AF opening is selectively blocked by a light-shielding blade, thereby different optical paths. Two images are obtained. In Patent Document 2, two diaphragm blades are shifted on a plane perpendicular to the optical axis to obtain two images having different optical paths. According to the method of each patent document, a phase difference detection method can be realized only by a diaphragm switching mechanism without providing an imaging device other than for photographing or an optical system for dividing subject light. The cost increase due to can be suppressed.
JP-A-9-184972 Japanese Patent Laid-Open No. 2004-038114

  However, in the method of Patent Document 1, a light shielding blade, a motor for driving the light shielding blade, and the like are separately required. In the method of Patent Document 2, a separate motor is required for each diaphragm blade. For this reason, the method of each patent document did not necessarily suppress the cost increase sufficiently. Further, in the method of Patent Document 1, a disc-shaped diaphragm blade having a plurality of openings having different diameters is used. Naturally, a diaphragm blade in which a plurality of openings are formed must have a considerably large diameter with respect to each opening. For this reason, in the method of Patent Document 1, there is a concern about an increase in the size of the apparatus.

  The present invention has been made in view of the above problems, and an object of the present invention is to sufficiently suppress an increase in cost due to a phase difference detection method without increasing the size of the apparatus.

  In order to achieve the above object, a digital camera of the present invention includes a photographic lens including a focus lens movable in an optical axis direction, an image sensor that images subject light formed by the photographic lens, and the focus lens. A lens moving means for moving in the optical axis direction, a first exposure opening provided on the optical axis of the photographing lens, and a sliding movement in a sliding direction substantially perpendicular to the optical axis to expose the first exposure opening A plurality of diaphragm blades that adjust the amount of the subject light incident on the image sensor by increasing or decreasing the area, and each of the diaphragm blades is formed in an area smaller than the first exposure aperture. A diaphragm mechanism having a second exposure opening, a motor, and sliding each diaphragm blade in the sliding direction according to the rotation amount of the motor, thereby A closed state that closes the exposure opening, an open state that exposes the first exposure opening, and a center of the second exposure opening that is shifted from the center of the first exposure opening by a predetermined amount in the sliding direction to open the second exposure opening. A second exposure in which the second exposure opening is overlapped with the first opening so as to be symmetric with respect to the first exposure state across the center of the first exposure opening. A diaphragm mechanism driving means including a drive transmission mechanism for changing the state of the diaphragm mechanism to a state; first image data acquired by performing imaging with the diaphragm mechanism in the first exposure state; and the diaphragm In-focus position for calculating the in-focus position of the focus lens by performing phase difference detection type auto-focus processing based on the second image data acquired by performing imaging in the second exposure state Calculation And when the execution of the autofocus process is instructed, the first image data and the second image data are acquired and the in-focus position calculating unit calculates the in-focus position, and the lens moving unit And focusing control means for moving the focus lens to the in-focus position calculated by driving.

  The motor is preferably a stepping motor. The second exposure opening is preferably formed in an elliptical shape or a polygon shape that is long in a direction substantially orthogonal to the sliding direction. The center of the second exposure opening in the first exposure state and the second exposure state is shifted by a predetermined amount from the center of the first exposure opening in the sliding direction, and the center of the first exposure opening is the first exposure opening. It is preferable to be positioned so as to be inside the two exposure openings.

  The focus control means specifies a predetermined focus range including the focus position after the focus position is calculated by the focus position calculation means, and detects contrast for the specified focus range. It is preferable to perform a method of autofocus processing and move the focus lens to a focus position calculated by the contrast detection method autofocus processing.

  The diaphragm mechanism includes a first diaphragm blade in which a notch for exposing the first exposure opening and the second exposure opening are formed, and a second in which an opening for exposing the first exposure opening is formed. It is preferable that the aperture blade includes a case in which the first exposure opening is formed and the first aperture blade and the second aperture blade are slidably accommodated in the sliding direction.

  The drive transmission mechanism includes a first cam groove formed on the first diaphragm blade, a second cam groove formed on the second diaphragm blade, and a pin that engages with the first cam groove, Preferably, the first lever is rotated by the rotation of the motor, and the second lever is formed by a pin engaged with the second cam groove and rotated by the rotation of the first lever. .

  The drive transmission mechanism includes a first cam groove formed in the first diaphragm blade, a second cam groove formed in the second diaphragm blade, and a first pin engaged with the first cam groove. May be formed at one end, a second pin that engages with the second cam groove may be formed at the other end, and may include a lever that rotates following the rotation of the motor.

  The diaphragm mechanism includes a first diaphragm blade having a notch for exposing the first exposure opening, a second diaphragm blade having an opening for exposing the first exposure opening, A third diaphragm blade having a second exposure opening; and a case for accommodating the first diaphragm blade, the second diaphragm blade, and the third diaphragm blade slidably in the sliding direction. Also good.

  At this time, the drive transmission mechanism includes a first cam groove formed on the first diaphragm blade, a second cam groove formed on the second diaphragm blade, and a third cam groove formed on the third diaphragm blade. A cam groove, a pin that engages with the third cam groove, a first lever that rotates following the rotation of the motor, and a pin that engages with the first cam groove and the second cam groove And a second lever that rotates following the rotation of the first lever.

  It is preferable to provide a stereoscopic photograph creating means for creating a stereoscopic photograph by synthesizing the first image data and the second image data. 3D moving image creating means for creating a 3D moving image based on a plurality of the first image data and the second image data acquired by performing imaging while alternately switching between the first exposure state and the second exposure state. Is preferably provided.

  When shooting a moving image in the first exposure state, the continuous exposure is performed by periodically switching to the second exposure state, thereby capturing the moving image while periodically focusing the focus lens. It is preferable to have a moving image shooting mode. Further, in the continuous autofocus moving image shooting mode, only a portion that is shot in common with the first image data and the second image data is extracted from each image data, and the autofocus process is performed. The acquired second image data is preferably recorded as an image for one frame of a moving image.

  The autofocus device according to the present invention includes a photographic lens including a focus lens movable in the optical axis direction, an imaging element that images subject light formed by the photographic lens, and the focus lens in the optical axis direction. A lens moving means for moving, a first exposure opening provided on the optical axis of the photographing lens, and a sliding movement in a sliding direction substantially orthogonal to the optical axis to increase or decrease the exposed area of the first exposure opening. Accordingly, a plurality of aperture blades for adjusting the amount of the subject light incident on the image sensor, and a second exposure provided on any one of the aperture blades and having an area smaller than the first exposure aperture. An aperture mechanism having an aperture, a motor, and sliding the aperture blades in the slide direction in accordance with the rotation amount of the motor, thereby opening the first exposure aperture. A closed state, an open state in which the first exposure opening is exposed, and a center of the second exposure opening is shifted from the center of the first exposure opening by a predetermined amount in the sliding direction to move the second exposure opening to the first exposure opening. A first exposure state overlaid on the opening and a second exposure state in which the second exposure opening is overlaid on the first opening so as to be symmetrical with respect to the first exposure state across the center of the first exposure opening. A diaphragm mechanism driving means comprising a drive transmission mechanism for changing the state of the diaphragm mechanism, first image data acquired by performing imaging with the diaphragm mechanism in the first exposure state, and the diaphragm mechanism A focus position calculating means for performing a phase difference detection type autofocus process based on the second image data acquired by performing imaging in the second exposure state and calculating a focus position of the focus lens; , Auto When the execution of the focus processing is instructed, the first image data and the second image data are acquired, the in-focus position calculating unit calculates the in-focus position, and the lens moving unit is driven. Focus control means for moving the focus lens to the calculated focus position is provided.

  In the present invention, it is possible to adjust the amount of light incident on the image sensor with only one motor and to control the position of the second exposure opening in accordance with the phase difference detection type autofocus process. As a result, the number of parts can be reduced, and the cost increase due to the autofocus process of the phase difference detection method can be sufficiently suppressed. In addition, since the amount of light is adjusted by sliding the plurality of aperture blades and changing the exposed area of the first exposure aperture, an example using a disc-shaped aperture blade having a plurality of apertures having different diameters is used. Compared to the above, the increase in size of the apparatus can also be suppressed. Furthermore, power consumption can be reduced by driving each unit with only one motor.

  As shown in FIG. 1, a digital camera (autofocus device) 2 has a camera body 4 formed in a substantially rectangular parallelepiped shape. On the front surface of the camera body 4, there are a lens barrel 11 that holds a photographing lens 10, an optical viewfinder 12 for optically confirming a subject image, and a strobe light emitting unit 13 that irradiates the subject when performing photographing. Is provided.

  On the upper surface of the camera body 4, there are provided a release button 15 for instructing execution of shooting and a power button 16 for switching power ON / OFF. The release button 15 is a two-stage push switch. When the release button 15 is lightly pressed (half-pressed), various shooting preparation processes such as AF (automatic focus adjustment) and AE (automatic exposure adjustment) are performed. When the release button 15 is further pressed (fully pressed) from this half-pressed state, the camera body 4 is instructed to execute shooting, and the imaging signal for one screen subjected to shooting preparation processing is converted into image data.

  As shown in FIG. 2, a liquid crystal panel 20 and an operation unit 21 are provided on the back surface of the camera body 4. The liquid crystal panel 20 displays captured images, so-called through images at the time of shooting, various menu screens, and the like. The operation unit 21 includes a zoom operation button 22 for changing the magnification of the taking lens 10 to the wide-angle side or the telephoto side, a still image shooting mode for taking a still image, a moving image shooting mode for taking a movie, and an image on the liquid crystal panel 20. A mode selector switch 23 for selectively switching various modes such as a playback mode for playback display, a menu button 24 operated when displaying a menu screen on the liquid crystal panel 20 or determining a selection content, a menu screen A display switching button 25 for switching the display items and the like, a cross key 26 operated when moving a cursor in the menu screen, and the like are provided.

  As shown in FIG. 3, the photographing lens 10 includes a zoom lens 30, an aperture mechanism 31, and a focus lens 32 arranged along the optical axis L. A lens motor 33 is connected to the zoom lens 30. The lens motor 33 moves the zoom lens 30 to the wide-angle side or the telephoto side in conjunction with the operation of the zoom operation button 22. An iris motor 34 is connected to the diaphragm mechanism 31. The iris motor 34 adjusts the amount of light incident from the zoom lens 30 by changing the aperture area of the aperture mechanism 31 during the shooting preparation process when the release button 15 is half-pressed. A lens motor (lens moving means) 35 is connected to the focus lens 32. The lens motor 35 adjusts the focus of the photographing lens 10 to the near side or the infinity side by moving the focus lens 32 in the optical axis direction along with zooming of the zoom lens 30 and the like.

  Each motor 33, 34, 35 is connected to a motor driver 36. The motor driver 36 is connected to a CPU (focusing control means) 37 that comprehensively controls the digital camera 2, and transmits drive pulses to the motors 33, 34, and 35 based on a control signal from the CPU 37. . Each of the motors 33, 34, and 35 rotates the rotation shaft according to the drive pulse.

  Behind the photographic lens 10, a CCD (imaging device) 38 that images a subject image formed by the photographic lens 10 is arranged. A timing generator (TG) 39 controlled by the CPU 37 is connected to the CCD 38, and the shutter speed of the electronic shutter is determined by a timing signal (clock pulse) input from the TG 39.

  The image data output from the CCD 38 is input to a correlated double sampling circuit (CDS) 40, and output as R, G, B image data that accurately corresponds to the accumulated charge amount of each cell of the CCD 38. The image data output from the CDS 40 is amplified by an amplifier (AMP) 41 and converted into digital image data by an A / D converter (A / D) 42.

  The image input controller 43 is connected to the CPU 37 via the bus 44, and controls each part of the CCD 38, the CDS 40, the AMP 41, and the A / D 42 in accordance with a control command from the CPU 37. The image data output from the A / D 42 is temporarily recorded in the SDRAM 45.

  The image signal processing circuit 46 reads the image data from the SDRAM 45, performs various image processing such as gradation conversion, white balance correction, and γ correction processing, and records the image data in the SDRAM 45 again. The YC conversion processing circuit 47 reads out the image data subjected to various processes by the image signal processing circuit 46 from the SDRAM 45, and converts it into a luminance signal Y and color difference signals Cr and Cb. The LCD driver 48 reads the image data that has passed through the image signal processing circuit 46 and the YC conversion processing circuit 47 from the SDRAM 45, converts it into an analog composite signal, and displays it on the liquid crystal panel 20 as a through image.

  The compression / decompression processing circuit 50 compresses the image data YC converted by the YC conversion processing circuit 47 in a predetermined compression format such as TIFF or JPEG. The media controller 51 accesses the memory card 52 detachably attached to the media slot, and reads / writes compressed image data.

  A release button 15, a power button 16, an operation unit 21, an EEPROM 54, and the like are connected to the CPU 37. The EEPROM 54 stores various control programs and setting information. The CPU 37 reads these pieces of information from the EEPROM 54 to the SDRAM 45, which is a working memory, and executes various processes.

  In addition to the above, a strobe controller 56, an AE / AWB detection circuit 57, an AF detection circuit (focus position calculation means) 58, and the like are connected to the bus 44. The strobe control unit 56 causes the strobe light emitting unit 13 to emit light according to the strobe light emission signal transmitted from the CPU 37. The AE / AWB detection circuit 57 calculates a photometric value representing the luminance of the subject based on the integrated value of the luminance signal Y of the image data YC converted by the YC conversion processing circuit 47 and the color difference signals Cr and Cb. The calculation result is transmitted to the CPU 37. The CPU 37 determines the appropriateness of the exposure amount and white balance based on the photometric value transmitted from the AE / AWB detection circuit 57, and controls the operations of the aperture mechanism 31, the CCD 38, and the like.

  The AF detection circuit 58 calculates the in-focus position of the taking lens 10 based on the image data digitized by the A / D 42 and transmits the calculation result to the CPU 37. The CPU 37 ends the AF process by driving the lens motor 35 and moving the focus lens 32 to the calculated in-focus position during the shooting preparation process in response to half-pressing of the release button 15.

  As shown in FIG. 4, the diaphragm mechanism 31 includes a first diaphragm blade 60, a second diaphragm blade 61, a first lever 62, a second lever 63, and a case 64. Each diaphragm blade 60, 61 is formed in a substantially rectangular plate shape. The case 64 is formed in a substantially open box shape having a first concave surface 65 and a second concave surface 66 deeper than the first concave surface 65, and each diaphragm blade 60, 61 and each lever 62, 63.

  Two cam grooves 70, 71 and a long hole 72 are formed in the first aperture blade 60. When the cam groove 70 is accommodated in the case 64, the cam groove 70 engages with a pin 74 formed at one end of the first lever 62. On the other hand, the cam groove 71 engages with a pin 75 formed at one end of the second lever 63 when housed in the case 64. The elongated hole 72 is formed long in the direction of arrow A that is substantially parallel to the longitudinal direction of each of the first diaphragm blade 60 and the second diaphragm blade 61, and when accommodated in the case 64, the first concave surface of the case 64. It engages with a pin 76 provided on 65. A cam groove 77 and a long hole 78 are formed in the second aperture blade 61. The cam groove 77 engages with the pin 75 of the second lever 63 when accommodated in the case 64. The long hole 78 is formed long in the direction of the arrow A and engages with the pin 76 of the case 64 when accommodated in the case 64.

  An iris motor 34 is attached to the back surface of the case 64. A through hole (not shown) is formed in the second concave surface 66 of the case 64, and the rotating shaft 34 a of the iris motor 34 enters the case 64 through the through hole. Each lever 62, 63 is accommodated in the portion of the second concave surface 66 of the case 64. At this time, the second concave surface 66 is made deeper than the first concave surface 65 by the thickness of the levers 62 and 63 in order to prevent interference between the diaphragm blades 60 and 61 and the levers 62 and 63.

  The levers 62 and 63 are attached to the rotation shaft 34a of the iris motor 34 through through holes formed at the ends opposite to the pins 74 and 75, and rotate according to the drive of the iris motor 34. When the levers 62 and 63 rotate, the first diaphragm blade 60 moves in the direction of the arrow A by the engagement of the cam grooves 70 and 71 with the pins 74 and 75 and the engagement of the long hole 72 and the pin 76. Move the slide. Similarly, the second diaphragm blade 61 slides in the direction of the arrow A by the engagement of the cam groove 77 and the pin 75 and the engagement of the long hole 78 and the pin 76. The diaphragm mechanism 31 is arranged so that the width direction of the camera body 4 and the arrow A direction are substantially parallel.

  A substantially semicircular cutout 80 is formed in the first diaphragm blade 60. A circular opening 81 is formed in the second aperture blade 61. The case 64 is also formed with a circular opening (first exposure opening) 82. Each opening 81 and 82 and the notch 80 are formed with the same diameter. The case 64 is disposed so that the optical axis of the photographing lens 10 is orthogonal to the opening 82 and the optical axis passes through the center of the opening 82. The diaphragm mechanism 31 slides the diaphragm blades 60 and 61 to cover the opening 82 with the diaphragm blades 60 and 61, or expose the opening 82 through the notch 80 and the opening 81, thereby focusing the focus lens. The amount of light emitted to 32 is adjusted.

  Further, the first aperture blade 60 is formed with an AF opening (second exposure opening) 84 used in AF processing. The AF opening 84 is smaller in diameter than the notches 80 and the openings 81 and 82, and is formed in an area smaller than these. During the AF process, the diaphragm mechanism 31 slides the first diaphragm blade 60 and superimposes the AF opening 84 on the opening 82 of the case 64, so that the amount of light corresponding to the area of the AF opening 84 is increased. Is incident on the focus lens 32.

  As shown in FIG. 5, a hinge portion 91 provided with a through hole 90 through which the rotation shaft 34 a of the iris motor 34 is inserted is formed at the end of the second lever 63 opposite to the pin 75. The hinge portion 91 is thinner and narrower than the end portion of the second lever 63. On the other hand, at the end of the first lever 62 opposite to the pin 74, a recess 92 is formed by recessing a part thereof. The depth of the recess 92 is matched to the thickness of the hinge portion 91. The recess 92 is provided with a through hole 93 through which the rotation shaft 34 a of the iris motor 34 is inserted. The levers 62 and 63 are attached to the iris motor 34 in a state where the hinge portion 91 and the concave portion 92 are combined.

  The through hole 93 of the first lever 62 is formed to have the same diameter as the rotation shaft 34a. The first lever 62 is attached to the iris motor 34 by fitting the through hole 93 into the rotating shaft 34a. As a result, the first lever 62 rotates following the rotation of the rotating shaft 34a. On the other hand, the through hole 90 of the second lever 63 is formed slightly larger than the diameter of the rotating shaft 34a. Thereby, the 2nd lever 63 rotates freely with respect to the rotating shaft 34a. At this time, as shown in FIG. 6A, the center of each through-hole 90, 93 and the center of each pin 74, 75 are straightened by the engagement of the hinge 91 and the recess 92. A state of being aligned on a line (hereinafter referred to as a “straight state”), and a state of being rotated approximately 90 ° clockwise (when viewed from the back side) with respect to the first lever 62, as shown in FIG. Rotation is limited between.

  Further, as shown in FIG. 5, a torsion spring 95 is attached to each lever 62, 63. The torsion spring 95 is disposed on the back side of the levers 62 and 63 so that the rotating shaft 34a passes through the coil portion 95a. One end of the torsion spring 95 is attached to a substantially pin-shaped spring support portion 96 provided on the back side of the pin 74 of the first lever 62. The other end of the torsion spring 95 is attached to a substantially pin-shaped spring support portion 97 provided on the back side of the pin 75 of the second lever 63. The torsion spring 95 supports the second lever 63 so that the engaged state between the hinge portion 91 and the recess 92 is not released, and urges the levers 62 and 63 to be held in the above-described linear state.

  When the iris motor 34 is driven to rotate the first lever 62 clockwise (when viewed from the front side), the first lever 62 contacts the inner surface of the case 64 as shown in FIG. At this time, the second lever 63 is held in a linear state by the urging force of the torsion spring 95, and rotates following the rotation of the first lever 62. When the first lever 62 is rotated until it comes into contact with the inner surface of the case 64, the diaphragm blades 60, 61 slide by the cam grooves 70, 71, 77, the pins 74, 75, 76, and the long holes 72, 78. As a result, the opening 82 of the case 64 is closed by the diaphragm blades 60 and 61. Hereinafter, the state illustrated in FIG. 7A is referred to as a “closed state”.

  When the iris motor 34 is driven from this closed state to rotate the first lever 62 counterclockwise, as shown in FIG. 7B, the second lever 63 held in a linear state is driven to rotate, The second lever 63 contacts the inner side surface of the case 64. When the first lever 62 is rotated until the second lever 63 comes into contact with the inner surface of the case 64, the engagement between the cam grooves 70 and 71 and the pins 74 and 75 and the engagement between the long hole 72 and the pin 76 are performed. Accordingly, the first diaphragm blade 60 slides rightward from the closed position, and the notch 80 and the opening 82 overlap on the concentric axis. Further, due to the engagement between the cam groove 77 and the pin 75 and the engagement between the long hole 78 and the pin 76, the second diaphragm blade 61 slides to the left from the closed position, and the opening 81 and the opening 82 Overlap on the concentric axis. As a result, the opening 82 is exposed through the notch 80 and the opening 81. Hereinafter, the state illustrated in FIG. 7B is referred to as an “open state”.

  When the iris motor 34 is driven from this open state and the first lever 62 is further rotated counterclockwise, the second lever 63 is held in contact with the inner surface of the case 64 as shown in FIG. Only the first lever 62 rotates against the urging of the torsion spring 95. In the section in which only the first lever 62 rotates, the second aperture blade 61 is held at the same position as the open state. On the other hand, the first diaphragm blade 60 slides to the left by the engagement of the cam groove 70 and the pin 74.

  When only the first lever 62 is further rotated counterclockwise from the opened state and the first diaphragm blade 60 is slid to the left, the AF opening 84 is located above the openings 81 and 82 as shown in FIG. Overlap. The CPU 37 of the digital camera 2 is in a state where the center of the AF opening 84 is positioned on the right side of the optical axis of the photographing lens 10 (center of the opening 82) during the AF processing when the release button 15 is half-pressed (FIG. 8). (See (a)) and moving the first diaphragm blade 60 to the state where the center of the AF aperture 84 is located on the left side of the optical axis of the photographing lens 10 (see FIG. 8B), thereby Two different pieces of image data are acquired. The AF detection circuit 58 calculates the phase difference between the acquired image data, and calculates the focus shift direction and shift amount (that is, in-focus position) of the photographing lens 10 from the phase difference. Process.

  Hereinafter, the state illustrated in FIG. 8A is referred to as a “first AF state”, and the state illustrated in FIG. 8B is referred to as a “second AF state”. The image data acquired in the first AF state is referred to as “first AF image data”, and the image data acquired in the second AF state is referred to as “second AF image data”.

  The center of the AF opening 84 in the first AF state and the center of the AF opening 84 in the second AF state are aligned symmetrically across the optical axis. The alignment between the first AF state and the second AF state is controlled by the rotation amount of the iris motor 34. For this reason, a motor capable of controlling the amount of rotation, such as a stepping motor, is used as the iris motor 34. By using such a motor, it is not necessary to provide a sensor for controlling the amount of rotation such as a rotary encoder.

  Thus, the diaphragm mechanism 31 changes the diaphragm blades 60 and 61 to the above-described states in accordance with the rotational drive of the iris motor 34. The aperture mechanism 31 continuously changes the exposed area of the opening 82 by adjusting the amount of rotation of each lever 60, 61 between the closed state and the open state. For example, the CPU 37 appropriately adjusts the aperture area of the aperture mechanism 31 by driving the iris motor 34 in accordance with the photometric value calculated by the AE process.

  Next, the operation of the digital camera 2 configured as described above will be described with reference to the flowchart shown in FIG. When shooting with the digital camera 2, the subject is framed while viewing a through image displayed on the liquid crystal panel 20, and then the release button 15 is pressed halfway. When the release button 15 is pressed halfway, the CPU 37 starts AF processing.

  The CPU 37 that has started the AF process drives the iris motor 34 via the motor driver 36 to place the aperture mechanism 31 in the first AF state (see FIG. 8A). The CPU 37 having the aperture mechanism 31 in the first AF state drives the CCD 38, captures the subject image formed in the first AF state, and acquires first AF image data.

  The CPU 37 that has acquired the first AF image data drives the iris motor 34 again to place the aperture mechanism 31 in the second AF state (see FIG. 8B). The CPU 37 that has set the aperture mechanism 31 in the second AF state drives the CCD 38 to capture the subject image formed in the second AF state and acquire second AF image data.

  The CPU 37 that acquired each AF image data inputs each AF image data to the AF detection circuit 58. The AF detection circuit 58 that has received each AF image data calculates a phase difference between the AF image data, and calculates a focus position of the photographing lens 10 from the phase difference. The AF detection circuit 58 that has calculated the in-focus position transmits the calculation result to the CPU 37. The CPU 37 that has received the calculation result of the focus position from the AF detection circuit 58 drives the lens motor 35 via the motor driver 36 and moves the focus lens 32 to the calculated focus position. Thus, the AF process is completed. Note that the AF process is repeatedly performed while the release button 15 is half-pressed. Further, when the release button 15 is half-pressed, in addition to the above-described AF processing, for example, AE processing by the AE / AWB detection circuit 57 is performed. The AE / AWB detection circuit 57 is based on, for example, the first AF image data or the second AF image data described above, or image data acquired separately when the aperture mechanism 31 is opened (see FIG. 7B) or the like. Calculate the photometric value.

  The CPU 37 starts execution of photographing in response to the release button 15 being fully pressed. The CPU 37 that has started the shooting drives the iris motor 34 based on the photometric value calculated by the AE / AWB detection circuit 57, and the aperture 82 so that an appropriate amount of light enters the focus lens 32 and the CCD 38. Adjust the exposed area. Then, the CCD 38 is driven to acquire image data, and the acquired image data is recorded in the memory card 52.

  Thus, according to the present embodiment, the adjustment of the amount of light incident on the focus lens 32 and the CCD 38 with only one iris motor 34 and the position control of the AF aperture 84 accompanying the AF processing of the phase difference detection method. And can be done. As a result, the number of parts can be reduced, and the cost increase due to the phase difference detection AF process can be sufficiently suppressed. Further, since the amount of light is adjusted by sliding the diaphragm blades 60 and 61 and changing the exposed area of the opening 82, an example using a disk-shaped diaphragm blade having a plurality of openings with different diameters is used. Compared to the above, the increase in size of the apparatus can also be suppressed. Furthermore, the power consumption can be suppressed by driving each unit with only one iris motor 34.

  In the above embodiment, the circular AF opening 84 is shown. However, the shape of the AF opening is not limited thereto, and the first aperture blade 60 is, for example, like the AF opening 100 shown in FIG. You may form in the ellipse shape long in the direction substantially orthogonal to these slide directions. FIG. 10A shows a state in which the aperture mechanism 31 is in the first AF state, and FIG. 10B shows a state in which the aperture mechanism 31 is in the second AF state.

  Such an elliptical AF opening 100 can expand the opening area without increasing the slide movement amount of the first aperture blade 60 compared to the circular AF opening 84. As a result, the amount of light during AF processing can be increased and the accuracy of AF processing can be improved. Further, when the diaphragm mechanism 31 is set to each AF state, as shown in FIG. 10, the first diaphragm blade 60 so that the optical axis of the photographing lens 10 (center of the opening 82) is located inside the AF opening 100. It is preferable to perform positioning. By positioning the first aperture blade 60 in this way, the amount of light during AF processing can be further increased.

  When the length of the short side (lateral width) of the AF opening 100 is A and the diameter of the opening 82 is R, the short side A preferably has a relationship of R / 2 ≦ A ≦ R. Further, the AF aperture is not limited to an elliptical shape, and may be a polygonal shape that is long in a direction substantially orthogonal to the sliding direction of the first diaphragm blade 60 such as a rectangle or a hexagon.

  In the above embodiment, an example in which only phase difference detection AF processing is performed has been described. However, the present invention is not limited to this. For example, as shown in the flowchart of FIG. You may make it combine with the AF process of a system. In the flowchart of FIG. 11, after each AF image data is acquired in response to half-pressing of the release button 15, the in-focus range including the in-focus position is specified based on each AF image data. The in-focus range is specified by the AF detection circuit 58. For example, the AF detection circuit 58 calculates the in-focus position based on each AF image data, and specifies the range as the in-focus range by adding a predetermined distance before and after the calculated in-focus position. The AF detection circuit 58 that has specified the focus range transmits the specified focus range to the CPU 37.

  The CPU 37 that has received the in-focus range drives each lens motor 35 to move the focus lens 32 by a predetermined amount from close to infinity or from infinity to close to each point within the specified in-focus range. The AF evaluation circuit 58 calculates the focus evaluation value at. The focus evaluation value is obtained by performing contour extraction processing on a specific area of the image, for example, image data of the central portion of the captured image using a high-pass filter or the like, and extracting the contour signal and the luminance value of the image data of the central portion. It is obtained by accumulating. Further, the larger the focus evaluation value is, the more high-frequency components are in the portion, and the portion is in focus.

  The CPU 37 that has caused the AF detection circuit 58 to calculate the focus evaluation value of each point determines the point at which the focus evaluation value is maximum as the final in-focus position, and moves the focus lens 32 to that point, thereby performing AF processing. Exit.

  In a single-lens reflex digital camera or the like that performs phase difference detection AF processing using a plurality of image sensors, the accuracy of AF processing is improved by repeating the AF processing by the phase difference detection method a plurality of times. However, in the digital camera 2 that performs phase difference detection AF processing with one CCD 38 shown in the above embodiment, it is necessary to switch the state of the aperture mechanism 31 and the like, so that phase difference detection AF processing is performed a plurality of times. When it repeats, the problem that AF processing will take time will arise.

  On the other hand, when a single CCD 38 is used by specifying a rough range by phase difference detection AF processing and performing contrast detection AF processing on the range as shown in the flowchart of FIG. In this case, AF processing can be performed quickly and with high accuracy.

  Furthermore, in the above-described embodiment, an example in which the aperture mechanism 31 is used in the phase difference detection type AF processing has been described. However, the aperture mechanism 31 is not limited to this, and as illustrated in the flowchart of FIG. The aperture mechanism 31 may be used for shooting. Note that setting to a mode for taking a stereoscopic photograph may be performed via the menu button 24, for example. In the flowchart of FIG. 12, first, the AF process is performed as described above in response to the release button 15 being pressed halfway. The CPU 37 that has performed the AF process sets the aperture mechanism 31 to the first AF state in response to the release button 15 being fully pressed. The CPU 37 having the aperture mechanism 31 in the first AF state drives the CCD 38, captures the subject image formed in the first AF state, and acquires image data.

  As described above, the diaphragm blades 60 and 61 slide in a direction substantially parallel to the width direction of the camera body 4. As shown in FIG. 8A, the center of the AF aperture 84 in the first AF state when viewed from the front side of the aperture mechanism 31 is from the optical axis of the photographing lens 10 (the center of the aperture 82). Is also located on the right side. For this reason, when the aperture mechanism 31 is in the first AF state, only a part on the left side with respect to the photographing field angle of the photographing lens 10 is photographed (see FIG. 15). Hereinafter, the image data acquired in response to the full press of the release button 15 when the aperture mechanism 31 is in the first AF state is referred to as “left-eye image data”.

  The CPU 37 that has acquired the left eye image data sets the aperture mechanism 31 to the second AF state. The CPU 37 having the aperture mechanism 31 in the second AF state drives the CCD 38, captures the subject image formed in the second AF state, and acquires image data. As described above, the center of the AF opening 84 in the second AF state is aligned symmetrically with respect to the center of the AF opening 84 in the first AF state with the optical axis in between. For this reason, when the aperture mechanism 31 is in the second AF state, only a part on the right side of the photographing field angle of the photographing lens 10 is photographed. Hereinafter, the image data acquired in response to the full press of the release button 15 when the aperture mechanism 31 is in the second AF state is referred to as “right eye image data”.

  CPU37 which acquired each image data produces | generates three-dimensional photograph data by synthesize | combining each acquired image data. The CPU 37 that created the stereoscopic photo data records the created stereoscopic photo data on the memory card 52. In this way, by using the diaphragm mechanism 31, not only the phase difference detection type AF processing but also the creation of a stereoscopic photograph can be performed. Note that the stereoscopic photo data may be based on the so-called parallel method or crossing method in which the left eye image data and the right eye image data are arranged side by side, or by the so-called anaglyph method for viewing with red and blue glasses. It may be a thing.

  Note that the aperture mechanism 31 may be used not only for taking a 3D photograph but also for taking a 3D moving picture as shown in the flowchart of FIG. When the CPU 37 of the digital camera 2 is instructed to start shooting a three-dimensional moving image, first, the diaphragm mechanism 31 is set to the first AF state. The start of stereoscopic video shooting is instructed, for example, by fully pressing the release button 15 after setting the digital camera 2 to the stereoscopic video shooting mode using the mode switch 23 or the menu button 24.

  The CPU 37 that has set the aperture mechanism 31 in the first AF state drives the CCD 38, captures the subject image formed in the first AF state, and acquires left-eye image data. The CPU 37 that acquired the left eye image data records the left eye image data in the memory card 52. The CPU 37 that has recorded the left eye image data sets the aperture mechanism 31 to the second AF state. The CPU 37 having the aperture mechanism 31 in the second AF state drives the CCD 38, captures the subject image formed in the second AF state, and acquires right-eye image data. The CPU 37 that has acquired the right eye image data records the right eye image data in the memory card 52.

  The CPU 37 that has recorded the right eye image data in the memory card 52 sets the aperture mechanism 31 again to the first AF state, and acquires the left eye image data. The CPU 37 that acquired the left eye image data records the acquired left eye image data in the memory card 52 so as to be connected to the previously recorded left eye image data. In this way, the CPU 37 individually creates a left-eye moving image and a right-eye moving image in a predetermined format by recording each image data as an image for one frame while sequentially switching the state of the aperture mechanism 31. To do.

  Thereafter, the CPU 37 repeats the above-described procedure until the end of the shooting of the stereoscopic video is instructed by pressing the release button 15 fully or the like. In addition, as a method of reproducing and displaying a stereoscopic video from the created left-eye video and right-eye video, a parallel method, a crossing method, an anaglyph method, and the like are known as in the case of a stereoscopic photograph. Further, a method for reproducing and displaying a stereoscopic moving image is described in detail in, for example, Japanese Patent Laid-Open No. 7-307961. In this way, a three-dimensional moving image can be created by using the aperture mechanism 31. In this example, the left-eye image data and the right-eye image data are acquired frame by frame. However, the present invention is not limited to this, and the state of the aperture mechanism 31 is switched after acquiring several frames. You may do it.

  Furthermore, as shown in the flowchart of FIG. 14, the diaphragm mechanism 31 may be used to perform so-called continuous AF in which the focus is continuously adjusted during moving image shooting. When the CPU 37 of the digital camera 2 is instructed to start shooting a moving image, the CPU 37 first sets the aperture mechanism 31 to the first AF state. For example, the start of moving image shooting is instructed by fully pressing the release button 15 after setting the digital camera 2 to the moving image shooting mode using the mode switch 23, the menu button 24, or the like.

  The CPU 37 that has set the aperture mechanism 31 in the first AF state drives the CCD 38, captures the subject image formed in the first AF state, and acquires left-eye image data. The CPU 37 that has acquired the left eye image data records the left eye image data in the memory card 52 as an image for one frame of a moving image. Then, the CPU 37 repeats the acquisition of the left eye image data and the recording to the memory card 52 until the predetermined number of frames is reached.

  When the CPU 37 acquires the left eye image data of a predetermined number of frames, the CPU 37 sets the aperture mechanism 31 to the second AF state. The CPU 37 having the aperture mechanism 31 in the second AF state drives the CCD 38, captures the subject image formed in the second AF state, and acquires right-eye image data. The CPU 37 that has acquired the right eye image data inputs the right eye image data and the left eye image data acquired immediately before to the AF detection circuit 58. The AF detection circuit 58 that has received each image data obtains a phase difference between the image data, and calculates a focus position of the photographing lens 10 from the phase difference. The AF detection circuit 58 that has calculated the in-focus position transmits the calculation result to the CPU 37. The CPU 37 that has received the calculation result of the focus position from the AF detection circuit 58 drives the lens motor 35 via the motor driver 36 and moves the focus lens 32 to the calculated focus position.

  The CPU 37 that has moved the focus lens 32 records the acquired right-eye image data in the memory card 52 as an image for one frame of a moving image. The CPU 37 that has recorded the right-eye image data in the memory card 52 sets the aperture mechanism 31 to the first AF state again. Then, the CPU 37 repeats the above procedure until the end of moving image shooting is instructed by, for example, pressing the release button 15 fully. In this way, by using the aperture mechanism 31, it is possible to perform continuous AF at the time of moving image shooting. In this example, the left-eye image data is mainly captured and the right-eye image data is acquired for the AF processing. However, these may be reversed as a matter of course.

  By the way, as shown in FIG. 15, the left-eye image data and the right-eye image data have a parallax corresponding to the baseline length of the AF aperture 84 in the first AF state and the AF aperture 84 in the second AF state. Arise. For this reason, as shown in the flowchart of FIG. 14, if the acquired right-eye image data is recorded as it is as an image for one frame, a moving image with a sense of incongruity is displayed in which a shifted image is periodically displayed. End up.

  In order to prevent this, as shown in FIG. 15, an overlap area OA in which a common part is photographed may be extracted from each image data, and only this overlap area OA may be recorded as a moving image. Note that the overlap area OA of each image data may be calculated based on, for example, the base line length of the AF opening 84, the angle of view of the photographing lens 10, the zoom magnification, and the like.

  Next, a second embodiment of the present invention will be described. Note that the same functions and configurations as those of the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 16, the diaphragm mechanism 150 of the present embodiment includes a first diaphragm blade 160, a second diaphragm blade 161, a third diaphragm blade 162, a first lever 163, a second lever 164, and a torsion. A spring 165 and a case 166 are included. Each diaphragm blade 160, 161, 162 is formed in a substantially rectangular plate shape. The case 166 is formed in a substantially open box shape having a first concave surface 167 and a second concave surface 168 deeper than the first concave surface 167, and accommodates the above-described parts in its internal space.

  The first aperture blade 160 is formed with a cam groove 170 and a long hole 171. The cam groove 170 engages with a pin 172 formed at one end of the second lever 164 when housed in the case 166. The long hole 171 is formed long in the arrow B direction substantially parallel to the longitudinal direction of each of the diaphragm blades 160, 161, 162, and is provided on the first concave surface 167 of the case 166 when accommodated in the case 166. The pin 173 is engaged.

  A cam groove 175 and a long hole 176 are formed in the second aperture blade 161. The cam groove 175 engages with the pin 172 of the second lever 164 when accommodated in the case 166. The long hole 176 is formed long in the direction of the arrow B, and engages with the pin 173 of the case 166 when accommodated in the case 166. A slotted cam groove 177 is formed in the third aperture blade 162. The cam groove 177 is formed long in a direction substantially perpendicular to the arrow B direction, and engages with a pin 178 formed at one end of the first lever 163 when housed in the case 166.

  An iris motor 34 is attached to the back surface of the case 166. A through hole (not shown) is formed in the second concave surface 168 of the case 166, and the rotating shaft 34a of the iris motor 34 enters the case 166 through the through hole. Each lever 163, 164 is accommodated in the portion of the second concave surface 168 of the case 166. At this time, the second concave surface 168 is made deeper than the first concave surface 167 by the thickness of each lever 163, 164 in order to prevent interference between each diaphragm blade 160, 161, 162 and each lever 163, 164. .

  The first lever 163 is attached to the rotating shaft 34 a of the iris motor 34 through a through hole formed at the end opposite to the pin 178, and rotates according to the driving of the iris motor 34. The second lever 164 is rotatably attached to a pin 180 provided on the second concave surface 168 of the case 166 via a through hole formed at the end opposite to the pin 172.

  When the first lever 163 rotates according to the drive of the iris motor 34, the third diaphragm blade 162 slides in the direction of arrow B due to the engagement between the cam groove 177 and the pin 178. Further, when the first lever 163 rotates in the clockwise direction, an arc-shaped protrusion 182 formed at the end of the first lever 163 opposite to the pin 178 contacts the side surface of the second lever 164. As a result of this contact, the second lever 164 rotates about the pin 180 as an axis.

  When the second lever 164 rotates, the engagement of the cam groove 170 and the pin 172 causes the first diaphragm blade 160 to slide in the direction of arrow B. Further, when the second lever 164 rotates, the second diaphragm blade 161 slides in the direction of arrow B due to the engagement between the cam groove 175 and the pin 172. When the torsion spring 165 is accommodated in the case 166, one end is engaged with the second lever 164, and the other end is engaged with the pin 184 provided on the second concave surface 168 of the case 166. The torsion spring 165 urges the second lever 164 to rotate counterclockwise when the second lever 164 rotates clockwise by contact with the protrusion 182. The diaphragm mechanism 150 is arranged so that the width direction of the camera body 4 and the arrow B direction are substantially parallel.

  The first diaphragm blade 160 is formed with a substantially semicircular cutout 186. A circular opening 187 is formed in the second diaphragm blade 161. The case 166 is also formed with a circular opening 188. Each opening 187 and 188 and the notch 186 are formed with the same diameter. The case 166 is disposed so that the optical axis of the photographing lens 10 is orthogonal to the opening 188 and the optical axis passes through the center of the opening 188. The aperture mechanism 150 slides each aperture blade 160, 161, 162 to cover the aperture 188 with each aperture blade 160, 161, 162, or expose the aperture 188 through the notch 186 and the aperture 187. Thus, the amount of light emitted to the focus lens 32 is adjusted.

  Further, the third aperture blade 162 is formed with an AF opening 190 used in the AF process. The AF opening 190 is formed with a diameter smaller than the diameters of the notches 186 and the openings 187 and 188. The diaphragm mechanism 150 slides the third diaphragm blade 162 and overlaps the AF opening 190 on the opening 188 of the case 166, thereby performing the phase difference detection type AF processing as in the first embodiment. Realize.

  When the iris motor 34 is driven to rotate the first lever 163 clockwise, the first lever 163 contacts the inner surface of the case 166 as shown in FIG. When the first lever 163 is rotated until it contacts the inner side surface of the case 166, the protrusion 182 contacts the side surface of the second lever 164, and the second lever 164 rotates clockwise against the bias of the torsion spring 165. Rotate. When the second lever 164 rotates, the first diaphragm blade 160 and the second diaphragm blade 161 slide by the engagement of the pin 172 and the cam grooves 170 and 175 and the engagement of the pin 173 and the long holes 171 and 176. Moving. Thereby, the aperture mechanism 150 is set in a closed state in which the opening 188 of the case 166 is closed by the first aperture blade 160 and the second aperture blade 161.

  When the iris motor 34 is driven from this closed state to rotate the first lever 163 counterclockwise, the second lever 164 is also rotated counterclockwise by the urging of the torsion spring 165. Then, as shown in FIG. 17B, when the first lever 163 is rotated counterclockwise until the contact between the protrusion 182 and the side surface of the second lever 164 is released, the first rotation rotated counterclockwise. The two levers 164 come into contact with the inner surface of the case 166. When the second lever 164 rotates until it comes into contact with the inner surface of the case 166, the first diaphragm blade 160 is closed by the engagement between the cam groove 170 and the pin 172 and the engagement between the long hole 171 and the pin 173. The notch 186 and the opening 188 overlap on the concentric axis by sliding to the right from the position. Further, the engagement of the cam groove 175 and the pin 172 and the engagement of the elongated hole 176 and the pin 173 cause the second diaphragm blade 161 to slide to the left from the closed position, and the opening 187 and the opening 188 Overlap on the concentric axis. Thereby, the aperture mechanism 150 is set in an open state in which the opening 188 is exposed through the notch 186 and the opening 187.

  When the iris motor 34 is driven from this open state to further rotate the first lever 163 counterclockwise, the third diaphragm blade 162 slides to the left due to the engagement of the cam groove 177 and the pin 178. At this time, the first diaphragm blade 160 and the second diaphragm blade 161 are held at the same position as the open state by the engagement with the second lever 164.

  When the third diaphragm blade 162 slides to the left, the AF opening 190 overlaps the openings 187 and 188 as shown in FIG. Then, by adjusting the rotation amount of the iris motor 34, as in the first embodiment, the aperture mechanism 150 is in the first AF state shown in FIG. 18 (a) and the second AF shown in FIG. 18 (b). Set to state.

  As described above, the iris mechanism 150 of the present embodiment can also be switched to each state by the single iris motor 34, so that the same effect as that of the first embodiment can be obtained. Moreover, according to this embodiment, the shape of the cam groove formed in each diaphragm blade can be simplified as compared with the first embodiment. As a result, it is possible to suppress an increase in cost due to difficulty in processing the cam groove.

  Next, a third embodiment of the present invention will be described. As shown in FIG. 19, the aperture mechanism 200 of the present embodiment includes a first aperture blade 210, a second aperture blade 211, a lever 212, and a case 213. Each diaphragm blade 210, 211 is formed in a substantially rectangular plate shape. The case 213 is formed in a substantially open box shape having a first concave surface 214 and a second concave surface 215 deeper than the first concave surface 214, and the diaphragm blades 210 and 211 and the lever 212 are placed in the internal space. Accommodate.

  A cam groove 220 and a long hole 221 are formed in the first aperture blade 210. The cam groove 220 has a first section 220a formed in a substantially arc shape and a second section 220b formed in a straight line from one end of the first section 220a. The cam groove 220 engages with a pin 222 formed at one end of the lever 212 when housed in the case 213. The long hole 221 is formed long in the direction of the arrow C substantially parallel to the longitudinal direction of each of the diaphragm blades 210 and 211, and is a pin provided on the first concave surface 214 of the case 213 when accommodated in the case 213. 224 is engaged.

  A cam groove 226 and an elongated hole 227 are formed in the second aperture blade 211. The cam groove 226 includes a first section 226a formed in a substantially S shape and a second section 226b formed in a substantially arc shape from the first section 226a. The cam groove 226 engages with a pin 228 formed at the other end of the lever 212 when housed in the case 213. The elongated hole 227 is formed long in the direction of the arrow C, and engages with the pin 224 of the case 213 when accommodated in the case 213.

  An iris motor 34 is attached to the back surface of the case 213. A through hole (not shown) is formed in the second concave surface 215 of the case 213, and the rotating shaft 34a of the iris motor 34 enters the case 213 through the through hole. The lever 212 is accommodated in the portion of the second concave surface 215 of the case 213. At this time, the second concave surface 215 is made deeper than the first concave surface 214 by the thickness of the lever 212 in order to prevent interference between the diaphragm blades 210 and 211 and the lever 212.

  The lever 212 is attached to the rotation shaft 34 a of the iris motor 34 through a through hole formed near the center, and rotates according to the drive of the iris motor 34. When the lever 212 rotates, the first aperture blade 210 slides in the direction of the arrow C due to the engagement between the cam groove 220 and the pin 222 and the engagement between the long hole 221 and the pin 224. Similarly, the engagement of the cam groove 226 and the pin 228 and the engagement of the long hole 227 and the pin 224 cause the second diaphragm blade 211 to slide in the direction of the arrow C. The diaphragm mechanism 200 is arranged so that the width direction of the camera body 4 and the arrow C direction are substantially parallel.

  The first diaphragm blade 210 is formed with a substantially semicircular cutout 230. A circular opening 231 is formed in the second aperture blade 211. The case 213 is also formed with a circular opening 232. The openings 231 and 232 and the notch 230 are formed with the same diameter. The case 213 is disposed so that the optical axis of the photographing lens 10 is orthogonal to the opening 232 and the optical axis passes through the center of the opening 232. The aperture mechanism 200 slides the aperture blades 210 and 211, covers the aperture 232 with the aperture blades 210 and 211, and exposes the aperture 232 through the notch 230 and the aperture 231. The amount of light emitted to 32 is adjusted.

  Further, the first aperture blade 210 is formed with an AF opening 234 used in the AF process. The AF opening 234 is formed with a diameter smaller than the diameter of the notch 230 or each of the openings 231 and 232. The diaphragm mechanism 200 slides the first diaphragm blade 210 during the AF process, and overlaps the AF opening 234 on the opening 232 of the case 213, so that the phase difference detection method is the same as in the above embodiments. AF processing is realized.

  When the iris motor 34 is driven to rotate the lever 212 clockwise, the pin 222 comes into contact with the end of the first section 220a of the cam groove 220 as shown in FIG. At the same time, the pin 228 comes into contact with the end of the first section 226a of the cam groove 226. As described above, the pins 212 and 228 come into contact with the respective end portions of the cam grooves 220 and 226, so that the lever 212 is prevented from rotating. When the lever 212 is rotated clockwise until the rotation is prevented, the diaphragm blades 210 and 211 are slid by the cam grooves 220 and 226, the pins 222, 224 and 228, and the long holes 221 and 227, respectively. The diaphragm mechanism 200 is set in a closed state in which the opening 232 of 213 is closed by the diaphragm blades 210 and 211.

  When the iris motor 34 is driven from this closed state and the lever 212 is rotated counterclockwise until the first sections 220a and 226a of the cam grooves 220 and 226 are finished as shown in FIG. The engagement of the cam groove 220 and the pin 222 and the engagement of the elongated hole 221 and the pin 224 cause the first diaphragm blade 210 to slide to the right from the closed position, so that the notch 230 and the opening 232 are concentric. Overlapping on the axis. Further, the engagement between the cam groove 226 and the pin 228 and the engagement between the long hole 227 and the pin 224 causes the second diaphragm blade 211 to slide to the left from the closed position, and the opening 231 and the opening 232 Overlap on the concentric axis. Thereby, the aperture mechanism 200 is set in an open state in which the opening 232 is exposed through the notch 230 and the opening 231.

  When the iris motor 34 is driven from this open state and the lever 212 is further rotated counterclockwise, the first diaphragm is engaged by the engagement between the cam groove 220 and the pin 222 and the engagement between the long hole 221 and the pin 224. The blade 210 slides to the left from the open position. On the other hand, the cam groove 226 is formed so that the curvature of the second section 226b coincides with the rotational trajectory of the pin 228 when the second aperture blade 211 is in the open state. For this reason, even when the lever 212 further rotates counterclockwise from the opened state, the second aperture blade 211 is held at the same position as the opened state without sliding.

  When the first diaphragm blade 210 slides in the left direction, the AF opening 234 overlaps the openings 231 and 232 as shown in FIG. Then, by adjusting the amount of rotation of the iris motor 34, the diaphragm mechanism 200 is in the first AF state shown in FIG. 21A and the second AF state shown in FIG. Set to

  As described above, the iris mechanism 200 according to the present embodiment can be switched to each state by the single iris motor 34, so that the same effects as those of the above embodiments can be obtained. In each of the above embodiments, two levers, a torsion spring, and the like are used when transmitting the driving force of the iris motor 34. However, in this embodiment, only one lever 212 is required. For this reason, according to the present embodiment, the number of parts can be reduced, the configuration of the diaphragm mechanism can be further simplified, and the cost increase due to the AF processing of the phase difference detection method can be further suppressed as compared with the above embodiments.

  In each of the above embodiments, the digital camera 2 is shown as the autofocus device. However, the autofocus device is not limited to this, and for example, a so-called silver salt camera and a telescope that record a latent image on a photographic film. Or other optical devices such as binoculars.

It is the perspective view seen from the front direction which shows the composition of a digital camera roughly. It is the perspective view seen from the back direction which shows the composition of a digital camera roughly. 1 is a block diagram schematically showing an electrical configuration of a digital camera. It is a perspective view which shows the structure of an aperture mechanism schematically. It is a perspective view which shows the structure of a 1st lever and a 2nd lever. It is explanatory drawing which shows a mode that each lever is in a linear state, and a mode that it bent. It is explanatory drawing which shows a mode that a diaphragm mechanism is in a closed state, and a mode in an open state. It is explanatory drawing which shows a mode that a diaphragm mechanism is in a 1st AF state, and a mode in a 2nd AF state. It is a flowchart which shows the procedure of still image photography roughly. It is explanatory drawing which shows the elliptical opening for AF. 6 is a flowchart illustrating an example in which phase difference detection AF processing and contrast AF processing are combined. It is a flowchart which shows the example which image | photographs a three-dimensional photograph using an aperture mechanism. It is a flowchart which shows the example which image | photographs a three-dimensional moving image using an aperture mechanism. It is a flowchart which shows the example which performs continuous AF using an aperture mechanism. It is explanatory drawing which shows the example which extracts an overlap area | region. It is a perspective view which shows roughly the structure of the aperture mechanism which aimed at simplification of the shape of a cam groove. It is explanatory drawing which shows a mode that the aperture mechanism which aimed at simplification of the shape of a cam groove is in a closed state, and a state in an open state. It is explanatory drawing which shows a mode that the aperture mechanism which aimed at simplification of the shape of a cam groove in a 1st AF state, and a 2nd AF state. It is a perspective view which shows roughly the structure of the aperture mechanism which aimed at reduction of the number of parts. It is explanatory drawing which shows a mode that the aperture mechanism which aimed at reduction of a number of parts has a closed state, and a open state. It is explanatory drawing which shows a mode that the aperture mechanism which aimed at reduction of a number of parts is in a 1st AF state, and a mode in a 2nd AF state.

Explanation of symbols

2 Digital camera (autofocus device)
DESCRIPTION OF SYMBOLS 10 Shooting lens 31, 150, 200 Aperture mechanism 32 Focus lens 34 Iris motor (motor)
35 Lens motor (lens moving means)
37 CPU (focus control means)
38 CCD (imaging device)
58 AF detection circuit (focus position calculation means)
60, 160, 210 First diaphragm blade 61, 161, 211 Second diaphragm blade 62, 163 First lever 63, 164 Second lever 64, 166, 213 Case 70, 71, 77, 170, 175, 177, 220, 226 Cam groove 74, 75, 172, 178, 222, 228 Pin 80, 186, 230 Notch 81, 187, 231 Opening 82, 188, 232 Opening (first exposure opening)
84, 100, 190, 234 AF aperture (second exposure aperture)
162 Third aperture blade 212 Lever

Claims (15)

A photographic lens including a focus lens movable in the optical axis direction, an imaging element that images subject light imaged by the photographic lens, and a lens moving unit that moves the focus lens in the optical axis direction; In a digital camera that performs autofocus processing of a phase difference detection method and focuses the focus lens,
The first exposure opening provided on the optical axis of the photographic lens and the sliding exposure direction substantially orthogonal to the optical axis to increase / decrease the exposed area of the first exposure opening. An aperture mechanism that includes a plurality of aperture blades that adjust the amount of incident subject light; and a second exposure aperture that is provided on any one of the aperture blades and has a smaller area than the first exposure aperture; ,
A closed state in which the first exposure opening is exposed, and an open state in which the first exposure opening is exposed by sliding the diaphragm blades in the sliding direction according to the rotation amount of the motor, A first exposure state in which the center of the second exposure opening is shifted by a predetermined amount from the center of the first exposure opening in the sliding direction and the second exposure opening is overlaid on the first opening, and the center of the first exposure opening. A diaphragm mechanism driving means comprising a drive transmission mechanism that changes the state of the diaphragm mechanism to a second exposure state in which the second exposure opening is overlapped with the first opening so as to be symmetrical to the first exposure state. When,
First image data acquired by imaging with the aperture mechanism in the first exposure state, and second image data acquired by imaging with the aperture mechanism in the second exposure state An in-focus position calculating means for calculating an in-focus position of the focus lens by performing auto-focus processing of the phase difference detection method based on the above;
When the execution of the autofocus process is instructed, the first image data and the second image data are acquired and the in-focus position calculating unit calculates the in-focus position, and the lens moving unit is driven. And a focus control means for moving the focus lens to the focus position calculated as described above.   The digital camera according to claim 1, wherein the motor is a stepping motor.   3. The digital camera according to claim 1, wherein the second exposure opening is formed in an elliptical shape or a polygon shape that is long in a direction substantially orthogonal to the sliding direction.   The center of the second exposure opening in the first exposure state and the second exposure state is shifted by a predetermined amount from the center of the first exposure opening in the sliding direction, and the center of the first exposure opening is the first exposure opening. 4. The digital camera according to claim 1, wherein the digital camera is positioned so as to be inside the two exposure opening. 5.   The focus control means specifies a predetermined focus range including the focus position after the focus position is calculated by the focus position calculation means, and detects contrast for the specified focus range. 5. The digital camera according to claim 1, wherein an autofocus process is performed, and the focus lens is moved to a focus position calculated by the autofocus process of the contrast detection system. .   The diaphragm mechanism includes a first diaphragm blade in which a notch for exposing the first exposure opening and the second exposure opening are formed, and a second in which an opening for exposing the first exposure opening is formed. 6. A diaphragm blade and a case in which the first exposure opening is formed, and the first diaphragm blade and the second diaphragm blade are slidably accommodated in the sliding direction. The digital camera according to any one of the above.   The drive transmission mechanism includes a first cam groove formed on the first diaphragm blade, a second cam groove formed on the second diaphragm blade, and a pin that engages with the first cam groove, A first lever that rotates in accordance with the rotation of the motor, and a second lever that is formed with a pin that engages with the second cam groove and rotates in accordance with the rotation of the first lever. The digital camera according to claim 6.   The drive transmission mechanism includes a first cam groove formed on the first diaphragm blade, a second cam groove formed on the second diaphragm blade, and a first pin that engages with the first cam groove. 7. The digital camera according to claim 6, wherein a second pin formed on the second cam groove is formed at the other end and is rotated by the rotation of the motor.   The diaphragm mechanism includes a first diaphragm blade having a notch for exposing the first exposure opening, a second diaphragm blade having an opening for exposing the first exposure opening, and the second 3. A third diaphragm blade having an exposure opening, and a case for accommodating the first diaphragm blade, the second diaphragm blade, and the third diaphragm blade slidably in the sliding direction. Item 6. The digital camera according to any one of Items 1 to 5.   The drive transmission mechanism includes a first cam groove formed in the first diaphragm blade, a second cam groove formed in the second diaphragm blade, and a third cam groove formed in the third diaphragm blade. A pin that engages with the third cam groove is formed, a first lever that rotates following the rotation of the motor, and a pin that engages with the first cam groove and the second cam groove are formed. The digital camera according to claim 9, further comprising a second lever that rotates following the rotation of the first lever.   11. The digital camera according to claim 1, further comprising a stereoscopic photograph creating unit that creates a stereoscopic photograph by combining the first image data and the second image data.   3D moving image creating means for creating a 3D moving image based on a plurality of the first image data and the second image data acquired by performing imaging while alternately switching between the first exposure state and the second exposure state. The digital camera according to claim 1, wherein the digital camera is provided.   When shooting a moving image in the first exposure state, the continuous exposure is performed by periodically switching to the second exposure state, thereby capturing the moving image while periodically focusing the focus lens. The digital camera according to claim 1, wherein the digital camera has a moving image shooting mode.   In the continuous autofocus moving image shooting mode, only a portion that is shot in common with the first image data and the second image data is extracted from each image data and acquired during the autofocus process. 14. The digital camera according to claim 13, wherein the second image data is recorded as an image for one frame of a moving image. A photographic lens including a focus lens movable in the optical axis direction, an imaging element that images subject light imaged by the photographic lens, and a lens moving unit that moves the focus lens in the optical axis direction; In an autofocus device that performs autofocus processing of a phase difference detection method and focuses the focus lens,
The first exposure opening provided on the optical axis of the photographic lens and the sliding exposure direction substantially orthogonal to the optical axis to increase / decrease the exposed area of the first exposure opening. An aperture mechanism that includes a plurality of aperture blades that adjust the amount of incident subject light; and a second exposure aperture that is provided on any one of the aperture blades and has a smaller area than the first exposure aperture; ,
A closed state in which the first exposure opening is exposed, and an open state in which the first exposure opening is exposed by sliding the diaphragm blades in the sliding direction according to the rotation amount of the motor, A first exposure state in which the center of the second exposure opening is shifted by a predetermined amount from the center of the first exposure opening in the sliding direction and the second exposure opening is overlaid on the first opening, and the center of the first exposure opening. A diaphragm mechanism driving means comprising a drive transmission mechanism that changes the state of the diaphragm mechanism to a second exposure state in which the second exposure opening is overlapped with the first opening so as to be symmetrical to the first exposure state. When,
First image data acquired by imaging with the aperture mechanism in the first exposure state, and second image data acquired by imaging with the aperture mechanism in the second exposure state An in-focus position calculating means for calculating an in-focus position of the focus lens by performing auto-focus processing of the phase difference detection method based on the above;
When the execution of the autofocus process is instructed, the first image data and the second image data are acquired and the in-focus position calculating unit calculates the in-focus position, and the lens moving unit is driven. And an in-focus control means for moving the focus lens to the in-focus position calculated as described above.

Images