JP5137779B2 - Imaging apparatus, control method thereof, and program - Google Patents

Description

  The present invention suppresses defocus detection accuracy deterioration due to foreign matter adhering to the surface of an optical low-pass filter or the like in a phase difference type defocus detection sensor arranged on an image pickup apparatus using an image pickup device such as a CCD or CMOS sensor. Regarding technology.

  2. Description of the Related Art In recent years, many image pickup apparatuses that generate an image signal using an image pickup element such as a CCD or a CMOS sensor and record it as data, such as a digital camera and a digital video camera, have come to be used.

  Further, in the digital camera, as disclosed in Patent Document 1, when foreign matters such as dust adhere to an optical member disposed on the imaging optical axis in front of an imaging element such as a CCD or CMOS sensor. In addition, a technique for removing foreign matter by applying vibration to an optical member is known.

Further, as disclosed in Patent Document 2, there is known a technique for correcting so that the influence on a photographed image can be suppressed even when dust adheres to protective glass, a filter, or the like disposed in front of the image sensor. Yes.
JP 2007-134801 A JP 2007-215151 A

  In a system that detects the amount of defocus using a phase difference type defocus detection sensor placed on an image pickup device that uses an image sensor, if a foreign object adheres to the surface of an optical low-pass filter, etc. The output of the line sensor at the position where it falls is reduced.

  This state will be described with reference to FIGS. 1A to 1D.

  FIG. 1A shows a case where the line sensor A is not affected by foreign matter.

  After plotting the outputs of the line sensors A and B and shaping the waveform, the defocus value D1 is obtained by correlation calculation.

  On the other hand, FIG. 1B shows a case where foreign matter is attached to the Nth sensor which is a part of the line sensor A.

  As the output of the Nth sensor decreases, the output of each of the line sensors A and B is plotted, and the defocus value D2 is obtained by correlation calculation.

  If the line sensor A is not affected by foreign matter, but is affected by foreign matter, the defocus amount is shifted by D2-D1.

  The defocus detected at this time can be said to be a state in which an error of (D2-D1) is generated with respect to the ideal defocus amount.

  The above is a description of a state in which the defocus detection accuracy due to foreign matter adhesion is degraded.

  Next, FIG. 1C shows a case in which a parameter for correcting the influence of foreign matter adhesion is used in order to reduce the influence of the defocus amount shift when the shadow of the foreign matter is projected on the line sensor.

  When a foreign object adheres to the Nth sensor that is a part of the line sensor A, the output of the Nth sensor decreases.

  The output of the Nth sensor is corrected by adding the correction parameter h (N) to the output of the Nth sensor. The corrected output of each sensor of the line sensors A and B is plotted, and the defocus value D3 is obtained by correlation calculation.

  The defocus amount detected at this time causes an error of (D3-D1) with respect to the ideal defocus amount D1, but due to the effect of the output correction value, the defocus amount error is smaller than that without correction. Can be suppressed.

  As described above, in the system that corrects the output so that the influence of the foreign matter on the line sensor is reduced, it is possible to determine which line sensor contains the foreign matter and how large the foreign matter is. You need to associate the relationship.

  On the other hand, in a system having a function of removing foreign matter by vibrating a conventional optical component, it is known that the foreign matter is removed or moved when the foreign matter removing function is operated.

  FIG. 1D shows a case where, after the foreign matter removal function is activated, the correction parameter is continuously used when foreign matter is attached to the line sensor even though no foreign matter is left on the line sensor.

  When the foreign matter of the Nth sensor that is a part of the line sensor A is removed, the output of the Nth sensor returns to the original output level.

  If the foreign substance correction parameter h (N) is added to the output of the Nth sensor as before, there is a problem that the output after correction of the Nth sensor becomes larger than the original value.

  In subsequent AF calculation processing, the output of each of the line sensors A and B is plotted, and a defocus value D4 is obtained by correlation calculation.

  The defocus amount detected at this time causes an error of (D4-D1) with respect to the ideal defocus amount D1.

  It can be seen that the error of the defocus amount becomes larger due to the effect that the output of the Nth sensor is raised from the original output, compared to the case without foreign matter correction.

  As described above, in a system having an imaging surface line sensor and a foreign matter removal function, there is a problem that a defocus detection error increases if the foreign matter correction parameter is not appropriate.

  Therefore, the present invention has been made in view of the above-described problems, and the object of the present invention is to suppress the detection error of the defocus amount as much as possible even when foreign matter is attached to the line sensor for detecting the defocus amount. Is to do so.

  In order to solve the above-described problems and achieve the object, an imaging apparatus according to the present invention is arranged in two dimensions on an imaging element that photoelectrically converts a subject image formed by a photographing optical system, and on the imaging element. , A photoelectric conversion sensor that outputs a signal for detecting the defocus amount of the subject image by a phase difference detection method, an optical member disposed in front of the imaging element, and a foreign matter attached to the surface of the optical member. Storage means for storing foreign matter information including at least position and size information, vibration means for vibrating the optical member to remove foreign matter attached to the surface of the optical member, and the optical by the vibration means A calculating means for calculating a difference value between the output signal of the photoelectric conversion sensor before vibrating the member and the output signal of the photoelectric conversion sensor after vibrating the optical member by the vibrating means; A correction unit that corrects an output signal of the photoelectric conversion sensor using correction data based on the foreign substance information, and the correction data is updated when the difference value calculated by the calculation unit is equal to or greater than a predetermined value. And updating means.

  The image pickup apparatus control method according to the present invention includes an image pickup device that photoelectrically converts a subject image formed by a photographing optical system, and a two-dimensional array on the image pickup device, and the subject image formed by a phase difference detection method. A photoelectric conversion sensor that outputs a signal for detecting the amount of defocus, an optical member disposed in front of the image sensor, and information on at least the position and size of the foreign matter attached to the surface of the optical member A method for controlling an imaging apparatus, comprising: storage means for storing foreign matter information; and vibration means for vibrating the optical member to remove foreign matters attached to the surface of the optical member, the vibration means To calculate a difference value between the output signal of the photoelectric conversion sensor before the optical member is vibrated and the output signal of the photoelectric conversion sensor after the optical member is vibrated by the vibration means. A correction step of correcting the output signal of the photoelectric conversion sensor using correction data based on the foreign substance information, and the correction when the difference value calculated in the calculation step is a predetermined value or more. And an update process for updating data.

  According to the present invention, it is possible to suppress a defocus amount detection error as much as possible even when foreign matter is attached to the line sensor for detecting the defocus amount.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
In the present embodiment, a defocus detection sensor (photoelectric conversion sensor) based on a phase difference detection method arranged two-dimensionally on an image sensor that photoelectrically converts a subject image formed by a photographing optical system, and an optical component vibration system are provided. A camera having the foreign matter removing function used will be described.

  FIG. 2 is a diagram showing a block configuration of an electric circuit when the present invention is applied to a single-lens reflex digital camera.

  In FIG. 2, reference numeral 10 denotes a camera control microcomputer that controls the digital single-lens reflex camera.

  The power control unit 81 receives a control signal from the camera control microcomputer 10 and supplies power from the power source 80 to each part of the camera.

  The power switch 14 is connected to the camera control microcomputer 10, and when the power switch 14 is turned on, the camera is in an activated state. When the power switch 14 is not turned on, the camera is inoperative.

  When the photographer turns on the menu switch 17, the mode shifts to the menu mode. In the menu mode, the memory control circuit 50, the TFT control circuit 52, the TFT monitor 54, the TFT backlight 55, and the image display memory 56 are driven, and menu information is displayed on the TFT monitor 54. When the photographer operates the electronic dial 16, the SET button switch 19, the operation unit 20, and the like, the menu setting can be changed. The changed menu information is stored in the memory 58.

  When the photographer turns on the playback switch 18, the mode shifts to the playback mode.

  In the reproduction mode, the recording unit 62, the I / F 60, and the compression / decompression circuit 59 are driven to generate reproduction image data on the memory control circuit 50 and the image display memory 56. Further, the TFT control circuit 52, the TFT monitor 54, the TFT backlight 55, and the image display memory 56 are driven to display a reproduced image. When the photographer operates the electronic dial 16 or the like, the reproduced image can be changed.

  The camera control microcomputer 10 detects whether data communication with the lens control microcomputer 200 is possible via the lens connection interface 71.

  When the lens mounting detection switch 70 is on, it is determined that the lens (shooting optical system) is mounted and data communication with the lens control microcomputer 200 is possible, and data is transmitted between the camera control microcomputer 10 and the lens control microcomputer 200. Deliver. Specifically, each lens control data such as lens aperture control data, zoom control information, and distance ring control information is transferred. Note that 201 is an aperture control circuit, 202 is a zoom control circuit, and 203 is a distance measurement control circuit.

  Furthermore, the camera control microcomputer 10 detects whether the flash attachment detection switch 72 is on and whether data communication with the flash control microcomputer 100 is possible via the flash connection interface 73. When the flash 105 is attached and communication is possible, data is communicated between the camera control microcomputer 10 and the flash control microcomputer 100, such as flash control data, zoom position information, guide number, main capacitor charge amount, etc. Pass each flash control data. Reference numeral 101 denotes a flash light emitting unit, 102 a light amount sensor for flash light control, 103 a main capacitor charging control circuit, and 104 a zoom control circuit for controlling flash zooming.

  When the camera control microcomputer 10 detects that the first switch SW1 of the release switch 15 is turned on, the camera control microcomputer 10 shifts to a photographing mode, drives the photometry circuit 13 and measures the luminance of the object field, and acquires photometry control data.

  The distance measuring circuit 35 is a defocus detection sensor based on a phase difference method arranged on an image pickup apparatus using the image pickup element 30.

  The camera control microcomputer 10 drives the distance measuring circuit 35 and obtains AF data by calculating the defocus amount of the subject based on the output of the distance measuring circuit 35.

  When the camera control microcomputer 10 detects the ON state of the second switch SW2 of the release switch 15, the camera control microcomputer 10 performs a release operation. The camera control microcomputer 10 calculates the shutter control amount and the lens aperture control amount based on the above-mentioned photometry control data and AF data, drives the shutter control unit 11, and sends the lens aperture control amount and the measurement to the lens control microcomputer 200. The distance control drive amount is transferred and the lens diaphragm is driven.

  The camera control microcomputer 10 causes the memory control circuit 50 to start the control operation of the imaging circuit block.

  The image pickup circuit block includes an image pickup circuit 30 including an image pickup element, a timing generation circuit 31, an A / D conversion circuit 32 that performs A / D conversion on an output signal from the image pickup circuit 30, and an output from the A / D conversion circuit 32. It comprises an image processing circuit 33 that performs processing. Then, the memory control circuit 50 acquires image data by driving the imaging circuit block.

  When the image control mode is set, the camera control microcomputer 10 sends a display command to the memory control circuit 50 and the TFT control circuit 52 and generates display data based on the image data obtained by the image processing. The obtained display data is displayed on the TFT monitor 54.

  The vibration generation circuit 90 is a vibration generation circuit that drives a vibration actuator (vibration device) connected to an optical component such as an optical low-pass filter disposed in front of the image sensor, and is based on a signal from the camera microcomputer 10. A predetermined vibration is generated. When the foreign matter removing function is operated by driving the vibration generating circuit 90, the foreign matter adhering to the surface of the optical component in front of the imaging surface is removed or moved.

  The above is the description of the block configuration of the electric circuit of the single-lens reflex digital camera of the present embodiment.

  Next, FIG. 3 is a flowchart showing the phase difference AF (autofocus) operation of the digital single lens reflex camera of the present embodiment.

  When an AF operation is performed using a camera switch or the like, the AF operation starts from step S300.

  In step S310, the camera control microcomputer 10 sets an initial value for the distance measuring circuit 35 and performs device setting for driving the AF sensor. Subsequently, the process proceeds to step S320.

  In step S320, the distance measuring circuit 35 is driven to accumulate the line sensor A and the line sensor B.

  In step S330, the output waveforms of the line sensors A and B are read.

  In step S340, shading correction is performed to correct the output value waveforms of the line sensors A and B.

  In step S350, based on the read value obtained in step S340 and the foreign substance correction data (foreign substance information) stored in the memory such as the position information and size information of the foreign substance on the line sensor optical axis, Correction processing of the outputs of the sensors A and B is performed. Subsequently, the process proceeds to step S360.

  In step S360, waveform evaluation is performed on the sensor waveforms of the line sensor A and the line sensor B based on the data corrected in step S350. Subsequently, the process proceeds to step S370.

  In step S370, a defocus calculation process is performed from the result of the waveform evaluation in step S360, a defocus amount is calculated, and a prediction amount is calculated. The process proceeds to step S380.

  In step S380, if the amount of prediction is within a predetermined value, it is determined that it is in the focusing range, and the AF process is completed. Then, the process proceeds to step S400, the AF process is terminated, and the process returns to the main process.

  If the amount of prediction is not within the predetermined value in step S380, the focus lens is driven according to the amount of prediction because there is no in-focus state, and the process proceeds to step S320 for re-ranging.

  As described above, using the flowchart shown in FIG. 4, the line sensor signal deterioration correction process is performed based on foreign substance correction data such as position information and size information of the foreign substance on the optical axis of the phase difference AF line sensor. The operation has been described.

  FIG. 4 is a flowchart showing an update sequence of phase difference AF foreign matter correction data of the digital single lens reflex camera of the present embodiment.

  When the foreign matter removal operation by the vibration of the optical member is operated by a camera switch or the like, an AF foreign matter correction data update sequence is started from step S200 in order to correct the output of the AF sensor.

  In step S201, the camera control microcomputer sets an initial value of the distance measuring circuit 35, and performs device setting for driving the AF sensor. Subsequently, the process proceeds to step S210.

  In step S210, the first AF sensor unit is driven, and the line sensors A and B are accumulated. Subsequently, the process proceeds to step S211.

  In step S211, the output waveform A1 (*) and output waveform B1 (*) of each line sensor are read. Here, * is a symbol representing the sensor number. When sensors are arranged in n rows, the possible values of * are * = 1 to n. Subsequently, the process proceeds to step S212.

  In step S212, shading correction is performed, and the output value waveforms of the line sensor A and line sensor B are corrected. The corrected waveforms are A1 (*) 'and B1 (*)'. Subsequently, the process proceeds to step S220.

  In step S220, the camera control microcomputer 10 drives the vibration generation circuit 90. The vibration generation circuit 90 is a vibration generation circuit that drives a vibration actuator connected to an imaging surface optical component such as an optical low-pass filter disposed in front of the imaging device. Based on a signal from the camera microcomputer 10, a predetermined frequency is generated. Generates vibration.

  It is known that when the foreign matter removing function is operated by driving the vibration generating circuit 90, the foreign matter existing on the imaging surface optical component is removed or moved. Subsequently, the process proceeds to step S230.

  In step S230, the AF sensor unit is driven for the second time, and the line sensor A and the line sensor B are accumulated. Subsequently, the process proceeds to step S231.

  In step S231, the output waveform A2 (*) and output waveform B2 (*) of each line sensor are read. Subsequently, the process proceeds to step S232.

  In step S232, shading correction is performed, and the output value waveforms of the line sensor A and line sensor B are corrected. The corrected waveforms are A2 (*) 'and B2 (*)'. Subsequently, the process proceeds to step S233.

  In step S233, the corrected data A1 (*) ′ of the first output waveform of each line sensor A is compared with the corrected data A2 (*) ′ of the second output waveform. Further, the corrected data B1 (*) ′ of the first output waveform of each line sensor B is compared with the corrected data B2 (*) ′ of the second output waveform. Then, the following difference data (difference value) is obtained.

Difference data of line sensor A = A2 (*) ′ − A1 (*) ′
Difference data of line sensor B = B2 (*) ′ − B1 (*) ′
Then, the process proceeds to step S240.

  Here, the threshold values are Ka and Kb. Both (Ka, Kb) are predetermined values and are set in the storage area of the camera microcomputer 10.

  In step S240, it is evaluated whether or not the difference data of the line sensor A is less than the threshold value Ka, and whether or not the difference data of the line sensor B is less than the threshold value Kb.

  If the difference data of the line sensor A is less than the threshold value Ka and the difference data of the line sensor B is less than the threshold value Kb, the process proceeds to step S252. On the other hand, if the difference data of the line sensor A is greater than or equal to the threshold value Ka or the difference data of the line sensor B is greater than or equal to the threshold value Kb, the process proceeds to step S250.

  In step S252, the foreign substance correction data DDD is not changed. Then, the process proceeds to step S260.

  On the other hand, in step S250, the foreign matter correction data DDD is discarded, foreign matter address data is newly generated based on the difference data of the line sensor A or B, and the new foreign matter correction data (DDD) is generated based on the foreign matter address data. ').

  After the foreign substance correction data DDD is replaced with DDD ', the process proceeds to step S260.

  In step S260, the foreign matter correction data update sequence ends.

  As described above, in the present embodiment, the correction data group for correcting the output value when the output waveform of the phase difference line sensor is missing due to a foreign substance or the like is used. In addition, the degree of the result of comparing and calculating each sensor output waveform of the phase difference line sensor before operating the foreign matter removal function and each sensor output waveform of the phase difference line sensor after making the foreign matter removal function differential. Accordingly, it is determined whether or not to change the foreign matter correction parameter.

  Subsequently, in order to show the mechanism of the foreign matter correction data of the phase difference line sensor of the present embodiment, the operation of the foreign matter correction calculation of AF will be described below with reference to FIG. 5A and the flowchart of FIG.

  FIG. 5A shows the relationship between AF waveform data and foreign object correction.

  FIG. 5A is a plot of the output waveform of line sensor A or line sensor B.

  Since the correction processing of the output waveforms of the line sensor A and the line sensor B is common, the line sensor A will be described as an example here.

  FIG. 5A shows the output waveform of the line sensor A obtained in step S330, and the outputs A1 (k), A1 (k + 1) of the sensors k, k + 1, k + 2, k + 3, k + 4, k + 5, and k + 6 of the line sensor A, respectively. A1 (k + 2), A1 (k + 3), A1 (k + 4), A1 (k + 5), and A1 (k + 6) are shown. Hereinafter, a case where a foreign substance is present at the position of the sensor k + 2 will be described as an example.

  In step S340, shading correction is performed to correct the output value waveform of each sensor of the line sensor A. The corrected waveforms are S1 (k), S1 (k + 1), S1 (k + 2), S1 (k + 3), S1 (k + 4), S1 (k + 5), and S1 (k + 6), respectively. In the above description, FIG. 5A is described as showing the output waveform of the line sensor A, but in the following, FIG. 5A shows the signal waveform after the shading correction is performed on the output of the line sensor A. To do.

  In step S350, from the data of the position of the foreign matter and the correction value data in the memory of the camera microcomputer 10, the correction amount for the sensor k + 2 is set to h (k + 2), and the correction amounts of the other sensors are all set to zero. Correct.

  When each output of the line sensor A is corrected using the correction amount, S1 (k), S1 (k + 1), {S1 (k + 2) + h (k + 2)}, S1 (k + 3), S1 (k + 4), S1 ( k + 5) and S1 (k + 6).

  In this way, the foreign substance correction calculation is performed by adding the foreign substance correction data to the waveform after the shading correction.

  Step S360 and subsequent steps are as described above, and AF waveform evaluation is performed, and defocus calculation and prediction calculation are performed by correlation calculation between the line sensors A and B.

  The above is the operation of the AF foreign matter correction calculation using FIGS. 5A and 3.

  Next, the AF foreign matter correction data update sequence will be described with reference to FIGS. 5A, 5B, 5C, 5D and the flowchart of FIG.

  5A, 5B, and 5C are outputs A1 (k), A1 (k + 1), A1 (k + 2), and A1 (k + 3) of the sensors k, k + 1, k + 2, k + 3, k + 4, k + 5, and k + 6 of the line sensor A, respectively. , A1 (k + 4), A1 (k + 5), and A1 (k + 6). The correction values are h (k), h (k + 1), h (k + 2), h (k + 3), h (k + 4), h (k + 5), and h (k + 6). For simplification of description, it is assumed here that h (k + 2) is a positive value and other correction values are zero.

  FIG. 5A shows a case where there is a foreign substance at the position of the sensor k + 2.

  FIG. 5B shows a state in which foreign matter has been removed from the position of sensor k + 2.

  FIG. 5C is a diagram for expressing the overlap and difference between the waveforms in FIGS. 5A and 5B.

  FIG. 5D is a diagram in which the difference between FIGS. 5A and 5B is replaced with a vertical axis. Here, the threshold value is Ka.

  In correspondence with the flowchart of FIG. 4, FIG. 5A shows the output waveform of the line sensor A accumulated in step S210 and read in step S211. In step S212, shading correction is performed on each of these output values. In the above description, FIG. 5A has been described as showing the output waveform of the line sensor A, but in the following, FIG. 5A shows the signal A1 (k) ′ after the shading correction is performed on the output of the line sensor A. , A1 (k + 1) ′, A1 (k + 2) ′, A1 (k + 3) ′, A1 (k + 4) ′, A1 (k + 5) ′, and A1 (k + 6) ′.

  Hereinafter, a case where there is a foreign substance at the position of the sensor k + 2 will be described as an example.

  In step S220, the camera control microcomputer 10 drives the vibration generation circuit 90. The vibration generation circuit 90 is a vibration generation circuit that drives a vibration actuator connected to an imaging surface optical component such as an optical low-pass filter disposed in front of the imaging device. Based on a signal from the camera microcomputer 10, a predetermined frequency is generated. Generates vibration. When the vibration generation circuit 90 is driven to operate the removal function by vibration of the optical component, the foreign matter existing on the imaging surface optical component is removed or moved. As a result, the foreign matter at the position of k + 2 is also removed.

  In step S230, the second AF sensor unit is driven. FIG. 5B shows an output waveform of the line sensor A that is accumulated in step S230, obtained after reading in step S231, and after shading correction in step S222. A description will be given assuming that the foreign matter at the position of the sensor k + 2 has disappeared.

  In step S233, the waveforms of the first AF data and the second AF data are compared. This is shown in FIG. 5C.

  That is, it is shown that there is a difference between the waveform data A1 'and the waveform data A2' as the foreign matter at k + 2 is removed.

  Step S240 is to obtain the difference between the waveform evaluation values, and a conceptual diagram obtained by calculating the difference between the waveform data A2 'and the waveform data A1' is shown in FIG. 5D. As a result of eliminating the influence of the foreign matter on the sensor k + 2, the output difference of the sensor exceeds the threshold level Ka at the position of the sensor k + 2 of the waveform data A2 '.

  If the threshold level Ka is exceeded in step S240, the foreign substance correction data group is reset, and the correction value h (*) (* = k to k + 6) is reset based on the waveform data A2 ′. Set.

  After replacing the foreign substance correction data group, the process proceeds to step S260. Here, h (k + 2) = zero is set.

  On the other hand, if it is below the threshold level Ka in step S240, the foreign matter correction data group is used without change. Here, h (k + 2) is used as it is, and other correction values remain zero.

  Similarly, if the difference data of the line sensor A is less than the threshold value Ka and the difference data of the line sensor B is less than the threshold value Kb, the process proceeds to step S252. On the other hand, if the difference data of the line sensor A is greater than or equal to the threshold value Ka or the difference data of the line sensor B is greater than or equal to the threshold value Kb, the process proceeds to step S250.

  In step S252, the foreign substance correction data DDD is not changed.

  In step S260, the foreign matter correction data update sequence ends.

  The threshold values Ka and Kb are set to numerical values that are large enough to identify the difference due to foreign matter removal.

  The above is the description of the AF foreign matter correction data update sequence using FIGS. 5A to 5D and FIG. 4.

  As described above, according to the present embodiment, the detection error due to the foreign matter with respect to the defocus detected by the defocus detection sensor is changed by changing the foreign matter correction parameter according to the result of operating the foreign matter removal function. Can be less.

(Second Embodiment)
Subsequently, a second embodiment of the present invention will be described.

  A second embodiment of the AF foreign matter correction data update sequence will be described with reference to FIGS. 6A to 6D and FIG. The sequence up to step S232 in the flowchart of FIG. 4 is the same as that in the first embodiment.

  In the description following step S232 in FIG. 4, FIGS. 6A, 6B, and 6C show the outputs A1 (after shading correction for the sensors k, k + 1, k + 2, k + 3, k + 4, k + 5, and k + 6 of the line sensor A). k) ′, A1 (k + 1) ′, A1 (k + 2) ′, A1 (k + 3) ′, A1 (k + 4) ′, A1 (k + 5) ′, and A1 (k + 6) ′. The correction values are h (k), h (k + 1), h (k + 2), h (k + 3), h (k + 4), h (k + 5), and h (k + 6). For simplification of description, it is assumed here that h (k + 2) is a positive value and other correction values are zero.

  FIG. 6A shows a waveform in which the output after the shading correction of the line sensor A is generated into a smooth curve by filtering, and shows a case where there is a foreign substance at the position of the sensor k + 2.

  FIG. 6B shows a waveform that similarly generates a smooth curve, but shows a state in which foreign matter has been removed from the position of sensor k + 2.

  In step S234 in FIG. 7, the waveforms of the first and second AF data are compared.

  FIG. 6C is a diagram for representing the difference between the waveform of the line sensor A1 (FIG. 6A) and the waveform of the line sensor A2 (FIG. 6B) obtained in step S234 of FIG.

  FIG. 6D is a diagram in which the difference between FIGS. 6A and 6B is replaced with a vertical axis.

In step S241, if the difference between the outputs of the sensors is Δ (*) * = k to k + 6,
Δk = A2 (k) ′ − A1 (k) ′
Δk + 1 = A2 (k + 1) ′ − A1 (k + 1) ′
Δk + 2 = A2 (k + 2) ′ − A1 (k + 2) ′
Δk + 3 = A2 (k + 3) ′ − A1 (k + 3) ′
Δk + 4 = A2 (k + 4) ′ − A1 (k + 4) ′
Δk + 5 = A2 (k + 5) ′ − A1 (k + 5) ′
Δk + 6 = A2 (k + 6) ′ − A1 (k + 6) ′
It becomes. The maximum data (peak value) in the difference data group is obtained and set to maxΔ (*) * = k to k + 6. Subsequently, the process proceeds to step S242.

  In step S242, it is determined whether maxΔ (*) is equal to or greater than a predetermined value Ka. If maxΔ (*) is less than the threshold value Ka, the process proceeds to step S252. If maxΔ (*) is equal to or greater than the threshold value Ka, the process proceeds to step S250.

  In step S252, the foreign substance correction data DDD is not changed. Then, the process proceeds to step S260.

  In step S260, the foreign matter correction data update sequence ends.

  The above is the second embodiment of the AF foreign matter correction data update sequence.

  According to the second embodiment, when the foreign matter removing function is operated, the waveform of the output of the line sensor A is a smooth curve by filtering or the waveform of the output of the line sensor B is a smooth curve by filtering. In addition, it is possible to compare the waveforms before and after removing the foreign matter in detail.

  By performing the waveform comparison of the line sensor A or the line sensor B in detail, the amount of change can be detected in more detail than in the first embodiment. By detecting in detail in this way, there is an effect that the detection error due to the foreign matter for the defocus detected by the defocus detection sensor can be further reduced.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 8 is a flowchart showing the operation of the third embodiment of the AF foreign matter correction data update sequence. The sequence up to step S232 in FIG. 4 is the same as that in the first embodiment.

  In step S235 following step S232 in FIG. 4, the difference between the waveform of the line sensor A1 (FIG. 6A) and the waveform of the line sensor A2 (FIG. 6B) is calculated.

FIG. 6D is a diagram in which the difference between the outputs of the sensors is Δ (*) * = k to k + 6, and the difference between the sensors is projected on the vertical axis. If the area (integral value) surrounded by the difference in FIG. 6D is s,
Area s = ∫ {Δ (*)} dx (* = k to k + 6)
It can be expressed as Subsequently, the process proceeds to step S247.

  In step S247, it is determined whether or not the area s is greater than or equal to a predetermined value.

  If the area s is less than the predetermined value, the process proceeds to step S252. If the area s is greater than the predetermined value, the process proceeds to step S250.

  In step S252, the foreign substance correction data DDD is not changed. Then, the process proceeds to step S260.

  In step S260, the foreign matter correction data update sequence ends.

  The above is the third embodiment of the AF foreign matter correction data update sequence.

  According to the third embodiment, when the foreign matter removing function is operated, the waveform of the output of the line sensor A is a smooth curve by filtering or the waveform of the output of the line sensor B is a smooth curve by filtering. And calculate the projected area. It is possible to make a detailed comparison using the projected area of the waveform before and after removing the foreign matter.

  By performing a comparison operation in detail using the projection area of the waveform of the line sensor A or the line sensor B, the amount of change can be detected in more detail than in the first embodiment. By detecting in detail in this way, it is possible to further reduce detection errors caused by foreign matter with respect to defocus detected by the defocus detection sensor.

(Other embodiments)
The object of each embodiment is also achieved by the following method. That is, a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but the present invention includes the following cases. That is, based on the instruction of the program code, an operating system (OS) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  Furthermore, the following cases are also included in the present invention. That is, the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the procedure described above.

It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. 1 is a block diagram illustrating a circuit configuration of a lens interchangeable single-lens reflex digital camera as an imaging apparatus according to a first embodiment of the present invention. 6 is a flowchart illustrating AF calculation processing of the imaging apparatus according to the first embodiment of the present invention. It is a flowchart which shows the AF foreign material correction data update sequence which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the arithmetic processing of the imaging device which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the AF foreign material correction data update sequence which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the AF foreign material correction data update sequence which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Camera control microcomputer 30 Imaging circuit 35 Ranging circuit 90 Vibration generating circuit

Claims (6)

An image sensor that photoelectrically converts a subject image formed by the photographing optical system;
A photoelectric conversion sensor that is two-dimensionally arranged on the image sensor and outputs a signal for detecting a defocus amount of the subject image by a phase difference detection method;
An optical member disposed in front of the image sensor;
Storage means for storing foreign matter information including information on at least the position and size of the foreign matter attached to the surface of the optical member;
Vibration means for vibrating the optical member in order to remove foreign matter adhering to the surface of the optical member;
A difference value between the output signal of the photoelectric conversion sensor before the optical member is vibrated by the vibration means and the output signal of the photoelectric conversion sensor after the optical member is vibrated by the vibration means is calculated. Computing means;
Correction means for correcting the output signal of the photoelectric conversion sensor using correction data based on the foreign matter information;
Updating means for updating the correction data when the difference value calculated by the calculating means is equal to or greater than a predetermined value;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein the correction data is correction data for correcting deterioration of an output signal of the photoelectric conversion sensor caused by a foreign matter attached to a surface of the optical member.   The calculation means includes an output signal of the photoelectric conversion sensor before the vibration means vibrates the optical member, and an output signal of the photoelectric conversion sensor after the vibration means vibrates the optical member. The imaging apparatus according to claim 1, wherein a peak value of a difference value is calculated, and the update unit updates the correction data when the peak value is equal to or greater than the predetermined value.   The calculation means includes an output signal of the photoelectric conversion sensor before the vibration means vibrates the optical member, and an output signal of the photoelectric conversion sensor after the vibration means vibrates the optical member. 2. The imaging apparatus according to claim 1, wherein an integral value of a difference value is calculated, and the update unit updates the correction data when the integral value is equal to or greater than the predetermined value. An image sensor that photoelectrically converts a subject image formed by a photographing optical system, and a signal that is two-dimensionally arranged on the image sensor and detects a defocus amount of the subject image by a phase difference detection method A photoelectric conversion sensor; an optical member disposed in front of the imaging element; storage means for storing foreign matter information including information on at least the position and size of the foreign matter attached to the surface of the optical member; and A method of controlling an imaging apparatus comprising: a vibration means for vibrating the optical member to remove foreign matter adhering to a surface,
The difference value between the output signal of the photoelectric conversion sensor before vibrating the optical member by the vibration means and the output signal of the photoelectric conversion sensor after vibrating the optical member by the vibration means is calculated. A calculation process;
A correction step of correcting the output signal of the photoelectric conversion sensor using correction data based on the foreign matter information;
An update step of updating the correction data when the difference value calculated in the calculation step is greater than or equal to a predetermined value;
An image pickup apparatus control method comprising:   A program for causing a computer to execute the control method according to claim 5.

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