JP6069853B2 - Focus detection device - Google Patents

Description

  The present invention relates to a focus detection apparatus.

  A contrast-type focus detection process that performs automatic focus adjustment using a focus evaluation value obtained by replacing a high-frequency component of an image captured by an image sensor with sharpness is known. In contrast-based focus detection processing, the focus adjustment value is sequentially acquired while performing a so-called wobbling operation, in which the focus adjustment optical system is moved back and forth in small increments during hill climbing operations. A method for determining the drive direction and focus position of an optical system is known.

  The interchangeable lens of a digital single-lens reflex camera has a heavy mass of a focus lens corresponding to an optical system for focus adjustment. Therefore, the focus lens has a problem that the wobbling operation cannot be performed at a high speed and a problem that a driving sound and vibration of the focus lens are generated during the mountain climbing operation. The driving sound and vibration of the focus lens are particularly noticeable when the focus lens is accelerated or decelerated.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a solution for optically driving an optical system or an image sensor that is lighter and smaller in weight than the focus lens in the optical axis direction with respect to the speed of the wobbling operation.

Patent 4437244

  In the invention of Patent Document 1, it is determined whether or not the focus lens needs to be driven based on the focus evaluation value obtained during the wobbling operation, and the focus lens is determined each time it is determined that the focus lens needs to be driven. Is accelerated and decelerated and moved by a predetermined distance. However, since the focus lens is repeatedly accelerated and decelerated during the focus detection process of the hill-climbing contrast method, it cannot be said that the problem of the driving sound and vibration of the focus lens has been solved particularly during movie shooting.

A focus detection apparatus according to a first aspect of the present invention includes a photographing optical system having a first focus lens and a second focus lens that moves within a range determined based on a position of the first focus lens, and the photographing An image sensor that receives light incident through the optical system and outputs a signal; a focus evaluation value calculation unit that calculates a focus evaluation value related to the focus of the photographing optical system from the contrast of an image generated from the signal; An in-focus position calculating unit that calculates a focus position of the imaging optical system that focuses light incident through the imaging optical system on the imaging element based on the focus evaluation value; and the second focus lens It is slightly moved in the optical axis direction from a move by a predetermined amount in a range, if the focusing position calculated by said focus position calculating unit was not in the range, the first focus And a control unit for moving the lens, a.

  ADVANTAGE OF THE INVENTION According to this invention, the focus detection apparatus in which suitable focus adjustment control is possible can be provided.

It is a block block diagram of the digital camera carrying the focus detection apparatus by one embodiment of this invention. It is a figure explaining the drive range of a wobbling lens. It is a figure explaining the conditions applied to the motion center position of a wobbling motion range. It is an example of the flowchart regarding a focus detection process. It is an example of the flowchart regarding the determination method of an image surface moving direction. It is an example of the flowchart regarding a focus detection process. It is a block block diagram of the camera body carrying the focus detection apparatus by one modification of this invention.

  FIG. 1 is a block diagram of an interchangeable lens digital camera equipped with a focus adjusting apparatus according to an embodiment of the present invention. The interchangeable lens digital camera in FIG. 1 includes a camera body 100 and a photographing lens 200. The taking lens 200 is detachably attached to the camera body 100.

  The photographing lens 200 includes a focus lens 210 (first focus lens) for performing focus adjustment, a focus lens driving unit 211 including a motor and a driving circuit for driving the focus lens 210, and an optical axis of the focus lens 210. A focus lens position detection unit 212 for detecting a position in the direction.

  The photographing lens 200 includes a wobbling lens 220 (second focus lens) for performing a wobbling operation, a wobbling lens driving unit 221 including a motor and a driving circuit for driving the wobbling lens 220, and a wobbling lens 220. A wobbling lens position detection unit 222 that detects a position in the optical axis direction.

  The driving sound generated when the wobbling lens driving unit 221 drives the wobbling lens 220 is smaller than the driving sound generated when the focus lens driving unit 211 drives the focus lens 210. For example, the driving sound of the wobbling lens 220 can be realized by designing the wobbling lens 220 to be lighter and smaller than the focus lens 210.

  FIG. 2 is a diagram for explaining the driving range of the wobbling lens 220. FIG. 2 shows a wobbling operation range 20, a mechanical limit range 21, a drive control range 22, and a position limit range 23. The wobbling lens 220 can move within the drive control range 22, and moves within the wobbling operation range 20 during the wobbling operation.

  The wobbling motion range 20 is a range centered on the variable motion center position Pwc, and is a range of the wobbling motion distance Dw from the motion center position Pwc in the subject side direction and the image sensor side direction, respectively. The wobbling lens 220 is positioned at the operation center position Pwc when the wobbling operation is not performed, and is driven within the wobbling operation range 20 when the wobbling operation is performed. The position of the operation center position Pwc is set so that the entire wobbling operation range 20 is included in the drive control range 22.

  The mechanical limit range 21 is a range in which the wobbling lens 220 can be mechanically driven. The mechanical limit range 21 has the center at the reference position P0, the subject side end point is the subject side end P1, and the image sensor side end point is the image sensor side end P2.

  The drive control range 22 is a range in which the drive of the wobbling lens 220 is limited in the drive control of the wobbling lens 220. The drive control range 22 is defined by a lower limit position Pm and an upper limit position Pp. The lower limit position Pm is an end point in the subject side direction of the drive control range 22. The position of the lower limit position Pm is variable and is set closer to the image sensor than the subject side end P1 of the mechanical limit range 21. The upper limit position Pp is an end point of the drive control range 22 in the image sensor side direction. The position of the upper limit position Pp is variable and is set closer to the subject side than the image sensor side end P2 of the mechanical limit range 21.

  The position limit range 23 is a range used for position control of the operation center position Pwc. One end of the position limit range 23 is located at the position Pm + Dw of the wobbling operation distance Dw from the lower limit position Pm of the drive control range 22 to the image sensor side direction, and the other end is located from the upper limit position Pp of the drive control range 22 toward the subject side. It is at the position Pp-Dw of the wobbling operating distance Dw.

  The taking lens 200 includes a lens controller 250 and a nonvolatile memory 251. The lens controller 250 controls the focus lens driving unit 211, the focus lens position detecting unit 212, the wobbling lens driving unit 221, and the wobbling lens position detecting unit 222 in accordance with instructions from the camera body 100.

  Information regarding the image plane movement direction is transmitted from the camera body 100 to the lens controller 250. The lens controller 250 determines a driving direction and a driving speed for moving the focus lens 210 or the wobbling lens 220 in order to move the scheduled imaging plane of the photographing lens 200 in the direction specified by the camera body 100. The driving direction is determined by the moving direction of the image plane and the power of the lens to be driven.

In the focus adjustment operation, the lens controller 250 first drives the wobbling lens 220 without driving the focus lens 210. When the photographic lens 200 is not in focus, the lens controller 250 changes (adds or subtracts) the set value of the operation center position Pwc by a predetermined distance Dfs when the driving direction is determined. At this time, the lens controller 250 determines whether or not the changed operation center position Pwc exceeds the position limit range 23. The lens controller 250 moves the wobbling lens 220 to the operation center position Pwc when the changed operation center position Pwc does not exceed the position limit range 23, that is, when the following conditional expression (1) is satisfied. On the other hand, the lens controller 250 drives the focus lens 210 when the changed operation center position Pwc exceeds the position limit range 23, that is, when the conditional expression (1) is not satisfied.
Pm + Dw ≦ Pwc ≦ Pp−Dw (1)

  At this time, the lens controller 250 moves the focus lens 220 so that the image plane moves in the same direction as the image plane moved by the wobbling lens 220. Then, the lens controller 250 returns the position of the wobbling lens 220 to the reference position P0.

  FIG. 3 illustrates a situation where the conditional expression (1) is not satisfied because the lens controller 250 changes the operation center position Pwc. In FIG. 3, the operation center position Pwc (= P0) of the wobbling operation range 20 illustrated in FIG. 2 is changed three times by a predetermined distance Dfs in the image sensor side direction. As a result, Pwc> Pp−Dw, and conditional expression (1) is not satisfied. When the operation center position Pwc moves from the reference position P0 to the image sensor side by three times the predetermined distance Dfs, the focus lens 210 is moved by the wobbling lens 220 so that the image plane moves in the same direction as the image plane movement direction. Then, the operation center position Pwc is returned to the reference position P0.

  In the nonvolatile memory 251, the reference position P0 of the mechanical limit range 21, the subject side end P1, and the image sensor side end P2, the wobbling operation distance Dw of the wobbling operation range 20, and the predetermined distance Dfs are stored in advance. Yes. The predetermined distance Dfs is set to be smaller than the wobbling operation distance Dw.

  The camera body 100 includes an image sensor 101, an analog signal processing unit 102, an A / D converter 103, a digital signal processing unit 111, a buffer memory 112, an Enc / Dec processing unit 113, an external storage medium 115, a VRAM 120, and an LCD monitor 121. A microphone 140, a speaker 141, an audio processing unit 142, a body controller 150, and an operation unit 180 are included.

  The image sensor 101 is configured by a CCD image sensor, a MOS type image sensor, or the like. The subject image formed by the photographing lens 200 is projected on the imaging surface of the imaging element 101. The imaging element 101 outputs an electrical signal (imaging signal) corresponding to the light intensity of the subject image formed on the imaging surface to the analog signal processing unit 102.

  The analog signal processing unit 102 includes a CDS circuit, an AGC circuit, a color separation circuit, and the like, and performs various types of analog signal processing on the imaging signal output from the imaging element 101. The imaging signal processed by the analog signal processing unit 102 is output to the A / D converter 103. The A / D converter 103 converts the imaging signal processed by the analog signal processing unit 102 from an analog signal to a digital signal. The image signal A / D converted by the A / D converter 103 is input to the digital signal processing unit 111 and the body controller 150.

  The digital signal processing unit 111 includes signal processing circuits such as a gain control circuit, a luminance signal generation circuit, and a color difference signal generation circuit. The digital signal processing unit 111 performs various image processing such as edge enhancement, gamma correction, and white balance adjustment on the image signal A / D converted by the A / D converter 103.

  The buffer memory 112 stores data for a plurality of frames captured by the image sensor 101. The digital signal processing unit 111 uses the buffer memory 112 as a work area when executing various image processing such as contour enhancement, gamma correction, and white balance adjustment. The imaging signal input to the digital signal processing unit 111 is stored in the buffer memory 112. The imaging signal stored in the buffer memory 112 is read each time various image processing such as contour enhancement, gamma correction, and white balance adjustment is performed, and the processed imaging signal is stored in the buffer memory 112. The imaging signal that has been subjected to a series of processing by the digital signal processing unit 111 and stored in the buffer memory 112 is output to the Enc / Dec processing unit 113.

  The Enc / Dec processing unit 113 performs a data encoding process on the imaging signal that has been subjected to a series of processing by the digital signal processing unit 111 and stored in the buffer memory 112 into a predetermined data format, and stores the image data as an external storage such as a memory card. Recording on the medium 115. The data format encoded by the Enc / Dec processing unit 113 is, for example, a JPEG format for a still image and a format such as MPEG2 or H264 / AVC for a moving image. The Enc / Dec processing unit 113 performs data decoding when reading encoded image data from the external storage medium 115. The Enc / Dec processing unit 113 also includes an interface for performing data communication with the external storage medium 115.

  Image signals picked up at predetermined time intervals by the image pickup device 101 are subjected to signal processing by the analog signal processing unit 102, the A / D converter 103, and the digital signal processing unit 111, and then transferred to the VRAM 120. The transferred image data is stored in the VRAM 120. The LCD monitor 121 functions as an EVF (Electronic View Finder) at the time of shooting, and the image data stored in the VRAM 120 is displayed as an image called a through image. The LCD monitor 121 can display the image data stored in the external storage medium 115 as an image. The LCD monitor 121 transfers image data read from the external storage medium 115 to the VRAM 120 and reproduces and displays it on the LCD monitor 121.

  The microphone 140 collects sound during moving image shooting and outputs a sound signal to the sound processing unit 142. The speaker 141 outputs sound when playing back a moving image. The audio processing unit 142 converts the audio signal output from the microphone 140 into digital data, and then compresses and encodes the audio signal into audio data of a predetermined audio format. The sound processing unit 142 transmits the sound data generated in this way to the body controller 150.

  When the focus lens 210 is driven during moving image shooting, the microphone 140 collects the drive sound, which may result in recording noise. Since the lens controller 250 drives the wobbling lens 220 and does not drive the focus lens 210 while the conditional expression (1) is satisfied, it is possible to reduce recording noise during moving image shooting.

  The body controller 150 includes a focus evaluation value calculation unit 151, an AE calculation unit 152, an AWB calculation unit 153, and other calculation units, and controls the entire camera. The body controller 150 can issue driving instructions for the focus lens 210 and the wobbling lens 220 via the lens controller 250.

  The focus evaluation value calculation unit 151 extracts a predetermined high-frequency component from the spatial frequency of the image data of the AF area set in advance on the imaging screen, and integrates the absolute value of the extracted high-frequency component to thereby obtain a focus evaluation value. Is calculated. When a plurality of AF areas of a predetermined size are arranged at a predetermined position in the imaging screen, the integrated value of the plurality of AF areas is a focus evaluation value, and the specific subject area set as the AF area or the AF area Represents the contrast of the image inside.

  The body controller 150 performs focus detection processing in cooperation with the lens controller 250. The body controller 150 determines the image plane movement direction (the infinity side direction and the closest side direction) based on the focus evaluation value calculated by the focus evaluation value calculation unit 151, and sends information regarding the image plane movement direction to the lens controller 250. Output.

  The AE calculation unit 152 performs automatic exposure calculation for photographing the subject with appropriate exposure based on the imaging signal from the A / D converter 103. The AWB calculation unit 153 sets a white balance adjustment gain based on the image signal (R, G, and B signals) from the A / D converter 103.

  The operation unit 180 is an operation member for performing operation instructions and various settings by the user, such as a release button, a moving image shooting button, and a setting button for performing various settings. For example, when the user presses the moving image shooting button, the digital camera starts moving image shooting, and when the user presses the moving image shooting button again, the moving image shooting ends.

(Focus detection processing during movie shooting)
A focus detection process at the time of moving image shooting will be described with reference to FIG. FIG. 4 is a flowchart of a contrast-type focus detection process by a hill-climbing operation using a wobbling operation. The processing in FIG. 4 is started by the body controller 150 when the moving image shooting button included in the operation unit 180 is pressed by the user, and is executed by the body controller 150 and the lens controller 250.

  In step S101, the body controller 150 causes the lens controller 250 to initialize the motion center position Pwc of the wobbling motion range 20. The lens controller 250 sets the operation center position Pwc to the reference position P0 stored in the nonvolatile memory 251.

  In step S102, the body controller 150 determines whether or not to finish moving image shooting. For example, the body controller 150 determines whether or not the user has pressed the moving image shooting button again. The body controller 150 ends the focus detection process when step S102 is affirmed, and advances the focus detection process to step S103 when step S102 is negative.

  In step S <b> 103, the body controller 150 and the lens controller 250 determine an image plane moving direction for focusing the photographing lens 200 by a wobbling operation using the wobbling lens 220. The body controller 150 determines the image plane movement direction as one of “do not move”, “infinity side direction”, and “closest side direction”. Details of the processing in step S103 will be described later.

  In step S104, the body controller 150 determines whether the image plane moving direction determined in step S103 is “does not move”, “infinity side direction”, or “closest side direction”. The body controller 150 advances the focus detection process to step S110 if the image plane movement direction determined in step S103 is “does not move”, and the focus detection process if the direction is “infinity direction” or “closest direction”. Advances to step S105.

  In step S105, the lens controller 250 changes (adds or subtracts) the motion center position Pwc by a predetermined distance Dfs in the driving direction of the wobbling lens 220 corresponding to the image plane movement direction determined in step S103. Thereby, the position of the wobbling lens 220 is changed.

  In step S106, the lens controller 250 updates the setting of the drive control range 22. The lens controller 250 sets the drive control range 22 based on changes in the optical characteristics (aberration and the like) of the photographing lens 200 due to the position of the focus lens 210, the position of the wobbling lens 220, the position of a zoom lens (not shown), and the like. Update. For example, when the optical performance deteriorates as the wobbling lens 220 approaches the end point of the mechanical limit range 21, the lower limit position Pm and the upper limit are set from the subject side end P1 and the image sensor side end P2 of the mechanical limit range 21. The drive control range 22 is set so as to keep the positions Pp away from each other.

  In step S107, the lens controller 250 determines whether or not the motion center position Pwc of the wobbling motion range 20 satisfies the conditional expression (1) described above. If the conditional expression (1) is satisfied, the lens controller 250 advances the focus detection process to step S102. If the conditional expression (1) is not satisfied (for example, the situation in FIG. 3), the lens controller 250 performs the focus detection process in step S108. Proceed to

  In step S108, the lens controller 250 moves the focus lens 210 so that the image plane moves in the same direction as the image plane movement direction due to the movement of the wobbling lens 220 from the reference position P0 to the operation center position Pwc. At this time, it is preferable to move the focus lens 210 by a distance that moves the same image plane as the moving amount of the image plane due to the movement of the wobbling lens 220 from the reference position P0 to the operation center position Pwc.

  In step S109, the lens controller 250 initializes the operation center position Pwc to the reference position P0. After step S109, the focus detection process proceeds to step S102.

  In step S110, the lens controller 250 moves the wobbling lens 220 to the operation center position Pwc. In step S111, the body controller 150 calculates a focus evaluation value using the focus evaluation value calculation unit 151, and stores the calculated focus evaluation value in a buffer memory 112, a memory (not shown) included in the body controller 150, or the like. Remember. In step S112, the body controller 150 determines whether it is necessary to restart the focus detection process due to a change in the subject or the like. If it is determined that it is necessary to restart, the focus detection process proceeds to step S102. If the body controller 150 determines that the restart is not necessary, the body controller 150 advances the focus detection process to step S113. In step S113, the body controller 150 determines whether to end moving image shooting as in step S102. The body controller 150 ends the focus detection process of FIG. 4 when step S113 is positively determined, and advances the focus detection process to step S112 when negative determination is made of step S113.

  FIG. 5 is an example of a flowchart regarding the processing executed by the body controller 150 and the lens controller 250 in step S103 of FIG. In step S1301 of FIG. 5, the body controller 150 and the lens controller 250 move the wobbling lens 220 to the operation center position Pwc. In step S1302, the body controller 150 calculates the focus evaluation value f0 using the focus evaluation value calculation unit 151.

  In step S1303, the body controller 150 and the lens controller 250 move the wobbling lens 220 in the closest direction by the wobbling operating distance Dw. In step S1304, the body controller 150 calculates the focus evaluation value f1 using the focus evaluation value calculation unit 151.

  In step S1305, the body controller 150 determines whether or not the focus evaluation value f0 is larger than the focus evaluation value f1. If the focus evaluation value f0 is greater than the focus evaluation value f1, the body controller 150 advances the process to step S1306. When the focus evaluation value f0 is equal to or less than the focus evaluation value f1, the body controller 150 determines the processing result of step S103 in FIG.

  In step S1306, the body controller 150 and the lens controller 250 move the wobbling lens 220 in the infinity direction by twice the wobbling operating distance Dw. As a result, the wobbling lens 220 is moved to the infinity direction side from the operation center position Pwc by the wobbling operation distance Dw. In step S <b> 1307, the body controller 150 calculates the focus evaluation value f <b> 2 using the focus evaluation value calculation unit 151.

  In step S1308, the body controller 150 determines whether or not the focus evaluation value f0 is greater than the focus evaluation value f2. If the focus evaluation value f0 is greater than the focus evaluation value f2, the body controller 150 advances the process to step S1309. When the focus evaluation value f0 is equal to or less than the focus evaluation value f2, the body controller 150 determines the processing result of step S103 in FIG.

  In step S1309, the body controller 150 determines whether or not the absolute value of the difference between the focus evaluation value f1 and the focus evaluation value f2 is equal to or less than a predetermined threshold T. If the determination in step S1309 is affirmative, the body controller 150 determines that the processing result in step S103 in FIG. If the determination in step S1309 is negative, the body controller 150 advances the process to step S1310.

  In step S1310, the body controller 150 determines whether or not the focus evaluation value f1 is larger than the focus evaluation value f2. When the focus evaluation value f1 is larger than the focus evaluation value f2, the body controller 150 determines the processing result of step S103 in FIG. When the focus evaluation value f1 is equal to or less than the focus evaluation value f2, the body controller 150 determines the processing result of step S103 in FIG.

(Focus detection processing during still image shooting)
The focus detection process during still image shooting will be described with reference to FIG. FIG. 6 is a flowchart of the contrast-type focus detection process by the hill-climbing operation using the wobbling operation as in FIG. The processing in FIG. 6 is started by the body controller 150 when the user half-presses the release button, and is executed by the body controller 150 and the lens controller 250. The flowchart of FIG. 6 is obtained by excluding the processes of step S102, step S112, and step S113 from the flowchart of FIG. The description of the same steps as those in FIG. 4 is omitted.

According to the embodiment described above, the following operational effects are obtained.
The digital camera according to the above-described embodiment includes the focus lens 210 and the wobbling lens 220 that can move in the optical axis direction, respectively, and the photographing lens in which the movement of the wobbling lens 220 is restricted by the mechanical restriction range 21 and the drive control range 22. 200, an image sensor 101 that receives a subject image from the photographing lens 200, and a body controller 150 that includes a focus evaluation value calculator 151 that calculates a focus evaluation value based on an output signal of the image sensor 101. The body controller 150 and the lens controller 250 determine the moving direction of the wobbling lens 220 for bringing the wobbling lens 220 to the in-focus position based on the focus evaluation value calculated by the focus evaluation value calculation unit 151 (step S103 in FIG. 4). FIG. 5). The body controller 150 and the lens controller 250 calculate the in-focus position of the wobbling lens 220 based on the focus evaluation value calculated every time the operation center position Pwc of the wobbling lens 220 is changed by a predetermined distance Dfs (step S105). (FIG. 5). When it is not possible to bring the photographic lens 200 to the in-focus position of the wobbling lens 220, that is, when the conditional expression (1) is not satisfied in step S107, the image plane due to the movement of the wobbling lens 220 is obtained. The focus lens 210 is moved so that the image plane moves in the same direction as the movement direction (step S108). The digital camera has such a configuration, and by reducing the number of times the focus lens 210 is driven during the focus detection process, it is possible to suppress the generation of driving sound and vibrations, thereby enabling suitable focus adjustment control.

The embodiment described above can be implemented with the following modifications.
(Modification 1) When the focus detection process described with reference to FIG. 4 is applied to a still image, the lens controller 250 may set the drive control range 22 to be narrower than that during moving image shooting. Thereby, it is possible to cope with still image shooting that requires higher image quality than during moving image shooting.

(Modification 2) When the photographic lens 200 has a zoom lens and the focal length of the photographic lens 200 is variable, the lower limit position Pm and the upper limit position Pp of the drive control range 22 are determined based on the focal length of the photographic lens 200. You may decide. When the drive control range 22 is determined based on the focal length of the photographing lens 200, the position limit range 23 is also determined based on the focal length.

(Modification 3) In FIG. 4, the lens controller 250 initializes the operation center position Pwc to the reference position P0 when the conditional expression (1) is not satisfied. However, the reference position P0 is set at other timings. May be initialized. For example, the motion center position Pwc may be initialized to the reference position P0 when the focus evaluation value changes greatly due to a composition change due to a panning operation or the like. Specifically, the focus evaluation values f0, f1, and f2 calculated in the process of step S103 are stored at least twice in the buffer memory 112 and the memory (not shown) of the body controller 150. Then, after affirmative determination is made in step S112 or after the processing in step S106, the focus evaluation value stored in the buffer memory 112 or the like is extracted, and the focus evaluation values f0 to f2 calculated most recently, and the previous one It is also possible to compare the focus evaluation values f0 to f2 calculated in the above and initialize the motion center position Pwc to the reference position P0 if the difference is equal to or greater than a predetermined threshold.

(Modification 4) In the above embodiment, a digital camera that performs a wobbling operation using the wobbling lens 220 has been described. However, the member used for the wobbling operation is not limited to the wobbling lens 220 alone. For example, instead of the wobbling lens 220, the image sensor may be slightly vibrated in the optical axis direction. Determining the moving direction of the image plane based on the focus evaluation value calculated by the focus evaluation value calculation unit 151 during the minute vibration of the image sensor, and determining the moving direction of the wobbling lens 220 based on the moving direction of the image plane. It may be.

  FIG. 7 is a block diagram of a camera body 300 that can execute a wobbling operation using an image sensor. The photographic lens 200 illustrated in FIG. 1 is detachably attached to the camera body 300 illustrated in FIG. The camera body 300 includes an image sensor 301 that can be micro-driven, an image sensor driver 302 that micro-drives the image sensor 301, an image sensor position detector 303 that detects the position of the image sensor 301, and an image sensor driver 302. 1 is different from the camera body 100 in FIG. 1 in that a body controller 350 that controls the image sensor position detection unit 303 is provided. The body controller 350 executes focus detection processing in cooperation with the lens controller 250 in the same manner as the body controller 150 in FIG.

  The above embodiments and modifications may be combined and executed as long as the features of the invention are not impaired. The above-described embodiments and modifications are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired.

20 wobbling operation range 21 mechanical limit range 22 drive control range 23 position limit range 100 camera body 101 image sensor 112 buffer memory 150 body controller 151 focus evaluation value calculation unit 200 photographing lens 210 focus lens 211 focus lens drive unit 212 focus lens position Detection unit 220 Wobbling lens 221 Wobbling lens driving unit 222 Wobbling lens position detection unit 250 Lens controller 251 Non-volatile memory

Claims (8)

A photographic optical system having a first focus lens and a second focus lens that moves within a range determined based on the position of the first focus lens ;
An image sensor that receives light incident through the photographing optical system and outputs a signal;
A focus evaluation value calculation unit that calculates a focus evaluation value related to the focus of the photographing optical system from the contrast of an image generated from the signal;
An in-focus position calculating unit that calculates an in-focus position of the imaging optical system that focuses the light incident through the imaging optical system on the image sensor, based on the focus evaluation value;
When the second focusing lens is slightly moved in the optical axis direction from a move by a predetermined amount in the range, the focusing position calculated by said focus position calculating unit was not in the range, the first focus A control unit for moving the lens;
A focus detection apparatus. The focus detection apparatus according to claim 1,
The control unit is a focus detection device that performs a wobbling operation each time the second focus lens is moved by a predetermined amount within the range . The focus detection apparatus according to claim 1 or 2,
The control unit is a focus detection device that operates the second focus lens so that the second focus lens does not exceed the range when the second focus lens is wobbled. The focus detection apparatus according to claim 3,
The photographing optical system has a zoom lens,
The range focus detection device is determined based on the position or focal distance of the photographing optical system before Symbol zoom lens. The focus detection apparatus according to claim 1,
The control unit is a focus detection apparatus that operates the center position of the wobbling operation so as not to exceed the range when the second focus lens is wobbling. In the focus detection apparatus according to any one of claims 1 to 5,
Wherein the control unit, the focus detection device for moving by a predetermined amount in the range of the second focus lens from the reference position is the center of the range. The focus detection apparatus according to claim 6,
The control unit, when the first focus lens is moved, moves the second focus lens to the reference position. The focus detection apparatus according to claim 1,
The control unit finely moves the image sensor in the optical axis direction, and determines a movement direction of the second focus lens based on the focus evaluation value calculated by the focus evaluation value calculation unit during the minute movement. Focus detection device.

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