JP2007025559A - Focusing position detecting method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a focusing position even when a high-luminance point light source exists such as in night view photography. <P>SOLUTION: A focus evaluated value and a photometric value are acquired all over the area from a close range to infinity, and a position X<SB>0</SB>where the focus evaluated value shows a peak is detected to acquire the photometric values Y<SB>1</SB>and Y<SB>2</SB>at positions X<SB>1</SB>and X<SB>2</SB>before and behind the position X<SB>0</SB>. A difference ΔY<SB>1-2</SB>between the acquired photometric values Y<SB>1</SB>and Y<SB>2</SB>is calculated, and the calculated difference ΔY<SB>1-2</SB>is compared with an allowable value α. When the difference ΔY<SB>1-2</SB>is under the allowable value α, the position X<SB>0</SB>where the focus evaluated value shows the peak is set as the focusing position. When the difference ΔY<SB>1-2</SB>is equal to or above the allowable value α, a position X<SB>3</SB>where the photometric value is minimum is detected and is set as the focusing position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a focus position detection method and apparatus, and more particularly to a focus position detection method and apparatus for detecting a focus position using a video signal obtained from an image sensor.

  A so-called contrast detection method is known as one of in-focus position detection methods for digital cameras. In this contrast detection method, a high-frequency component of a video signal obtained from an image sensor is extracted to obtain a focus evaluation value, and a position where the focus evaluation value reaches a peak is detected and set as a focus position (for example, Patent Documents 1 and 2).

  This contrast detection method has a drawback that accurate detection cannot be performed if a high-luminance point light source is present in the focus area, such as during night scene photography. This is because if the focus position is detected at a normal appropriate exposure level, the signal output of the point light source portion is saturated, and the high frequency component does not fluctuate even if the position of the focus lens changes.

Therefore, in Patent Document 3, when the in-focus position is detected at an appropriate exposure level and the in-focus position cannot be detected, the focus position is detected by reducing the exposure amount below the appropriate exposure. It has been proposed to perform in-focus position detection while avoiding saturation of the imaging signal.
JP 2000-13666 A JP 7-287162 A JP 2002-196220 A

  However, the method of Patent Document 3 has a drawback that it takes time to detect the in-focus position because the in-focus position detection operation must be performed a plurality of times.

  The present invention has been made in view of such circumstances, and provides an in-focus position detection method and apparatus capable of accurately detecting an in-focus position even when a high-luminance point light source is present, such as during night scene photography. The purpose is to do.

The invention according to claim 1, in order to achieve the object, obtains the focus evaluation value and the photometric value in the entire region from close to infinity, the focus evaluation value detecting the position X ₀ of the peak, the focus evaluation value The photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after the peak position X ₀ are acquired, the difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _{1 -2} compared with allowable values alpha, if the difference [Delta] Y _1-2 calculated is less than the allowable value alpha, the focus position of the position X ₀ of the peak focus evaluation value, the calculated difference [Delta] Y _1-2 are allowable value Provided is an in-focus position detection method characterized in that if it is α or more, the position X ₃ with the smallest photometric value is detected and the position X ₃ with the smallest photometric value is set as the in-focus position.

In the first aspect of the invention, the focus evaluation value detects the peak position X ₀ , and obtains the photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after that. Then, a difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _1-2 is compared with an allowable value α. If the difference [Delta] Y _1-2 is less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peak. On the other hand, if the difference [Delta] Y _1-2 are allowable value α or more, the photometric value to detect the lowest position X _3, to the position X ₃ and focus position. That is, in the present invention, even in a position where the focus evaluation value and a peak, when it difference [Delta] Y _1-2 photometry value of the position of the front and rear than the allowable value α that its position X ₀ is a pseudo by point source regarded as a peak, the photometric value sets the minimum position X ₃ to the true focus position. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

The invention according to claim 2, in order to achieve the object, obtains the focus evaluation value and the photometric value in the entire region from close to infinity, the focus evaluation value detecting the position X ₀ of the peak, the focus evaluation value The photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after the peak position X ₀ are acquired, the difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _{1 -2} compared with allowable values alpha, if the difference [Delta] Y _1-2 calculated is less than the allowable value alpha, the focus position of the position X ₀ of the peak focus evaluation value, the calculated difference [Delta] Y _1-2 are allowable value if more alpha, photometric value detects the minimum position X _3, photometric values obtains the photometric value Y _4, Y ₅ a minimum position before and after the position X ₃ X _4, X _5, obtained photometric value The difference ΔY _4-5 between Y ₄ and Y ₅ is calculated, the calculated difference ΔY _4-5 is compared with the allowable value β, and the calculated difference ΔY _{4 is} calculated. If _-5 is less than the allowable value beta, the photometric value focus position the minimum position X ₃ is, if the calculated difference [Delta] Y _4-5 are allowable value beta above that the focus position of the pan-focus position A featured focus position detection method is provided.

In the invention according to claim 2, detects the position _{X 0} of the peak focus evaluation value, obtains the photometric value _Y 1, _{Y 2} position _X 1, _{X 2} before and after. Then, a difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _1-2 is compared with an allowable value α. If the difference [Delta] Y _1-2 is less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peak. On the other hand, if the difference [Delta] Y _1-2 are allowable value α or more, the photometric value to detect the lowest position _{X 3,} obtains the photometric value _Y 4, _{Y 5} position _X 4, _{X 5} before and after, the difference ΔY _4-5 is calculated. Then, the calculated difference ΔY _4-5 is compared with the allowable value β. If the difference ΔY _4-5 is less than the allowable value β, the position X ₃ with the smallest photometric value is set as the in-focus position, and the difference ΔY _4-5 is If it is greater than or equal to the allowable value β, the pan focus position is set as the in-focus position. That is, in the present invention, even in a position where the focus evaluation value and a peak, when it difference [Delta] Y _1-2 photometry value of the position of the front and rear than the allowable value α that its position X ₀ is a pseudo by point source Consider it a peak. Then, the photometric value to detect the lowest position X _3, the difference [Delta] Y _4-5 photometric value of its longitudinal position determined is compared with the allowable value beta, when the difference [Delta] Y _4-5 is less than the allowable value β the photometric value sets the minimum position X ₃ to the in-focus position. On the other hand, if the difference ΔY _4-5 is greater than or equal to the allowable value β, the pan focus position is set to the in-focus position. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

In order to achieve the above object, the invention according to claim 3 obtains the focus evaluation value and the photometric value in the entire region from the nearest to infinity, detects the position X ₀ where the focus evaluation value is the peak, and the focus evaluation value is The photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after the peak position X ₀ are acquired, the difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _{1 -2} compared with allowable values alpha, if the difference [Delta] Y _1-2 calculated is less than the allowable value alpha, the focus position of the position X ₀ of the peak focus evaluation value, the calculated difference [Delta] Y _1-2 are allowable value if more alpha, photometric value detects the minimum position X _3, photometric values detected position X ₆ focus evaluation value of the peak in the vicinity of the minimum position X _3, peak focus evaluation value positions X ₆ The focus position detection method is characterized in that is set as a focus position.

In the invention according to claim 3, the focus evaluation value detects the peak position X ₀ , acquires the photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after that, and the acquired photometric values Y ₁ and Y to calculate a _second difference ΔY _1-2. Then, the difference [Delta] Y _1-2 calculated compared with the allowable value alpha, the difference [Delta] Y _1-2 is if less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peak. On the other hand, if the difference [Delta] Y _1-2 are allowable value α or more, the photometric value to detect the lowest position X _3, near its focus evaluation value detecting the position X ₆ peak, the focus position. That is, in the invention according to claim 3, even the position where the focus evaluation value and a peak, when it difference [Delta] Y _1-2 photometric value of its longitudinal position is larger than the allowable value alpha, the position X ₀ is Considered as a pseudo peak due to a point light source. Then, the photometric value to detect the lowest position X _3, the focus evaluation value in the vicinity of its front and rear detects the position X ₆ peak, the focus position. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

Invention, in order to achieve the object, when the photometric value is not the position of the peak in the focus evaluation value in the vicinity of the minimum position X _3, characterized in that the focus position of the pan-focus position according to claim 4 An in-focus position detection method according to claim 3 is provided.

The invention according to claim 4, in the invention according to claim 3, when the photometric value is not the position of the peak of the focus evaluation value in the vicinity of the minimum position X _3, to set the pan-focus position in the focus position.

  In order to achieve the above object, the invention according to claim 5 divides the focus area into a plurality of areas, acquires focus evaluation values in the entire area from the nearest to infinity for each area, and obtains the focus of each area obtained. In the in-focus position detection method that detects the in-focus position based on the evaluation value information, the focus evaluation value and the photometric value are obtained over the entire area from the closest to infinity for each area, and the maximum and minimum photometric values in each area. Value is detected, the difference between the maximum value and the minimum value of the photometric value in each area is calculated, and the focus position is detected by excluding information on the focus evaluation value of the area where the calculated difference is greater than or equal to the allowable value. A focus position detection method characterized by the above is provided.

  In the invention according to claim 5, the focus evaluation value and the photometric value are obtained in the whole area from the nearest to infinity for each divided area, and the maximum value and the minimum value of the photometric value in each area are detected. Then, a difference between the maximum value and the minimum value is calculated, and an in-focus position is detected by excluding an area where the calculated difference is an allowable value or more. That is, in the present invention, it is assumed that a high-brightness point light source exists in an area where the difference between the maximum value and the minimum value of the photometric value is an allowable value or more, and the in-focus position is detected by excluding that area. . Thereby, even if a high-luminance point light source exists in the focus area, the in-focus position can be accurately detected.

  In order to achieve the above object, the invention according to claim 6 divides the focus area into a plurality of areas, obtains focus evaluation values over the entire area from close to infinity for each area, and obtains the focus of each area obtained. In the in-focus position detection method for detecting the in-focus position based on the information of the evaluation value, the focus evaluation value is obtained in the entire area from the nearest to infinity for each area, and the peak position of the focus evaluation value in each area is detected. Focus position detection characterized by calculating the amount of deviation of the peak position of the focus evaluation value between each area and detecting the in-focus position by excluding information on the focus evaluation value of the area where the amount of deviation is greater than or equal to the allowable value Provide a method.

  In the invention according to claim 6, the focus evaluation values are acquired in the entire region from the nearest to infinity for each of the divided areas, and the peak position of the focus evaluation value in each area is detected. Then, the shift amount of the peak position between the areas is calculated, and the in-focus position is detected by excluding the area where the shift amount is equal to or larger than the allowable value. That is, in the present invention, it is assumed that a high-luminance point light source exists in an area where the deviation amount of the peak position of the focus evaluation value is greater than or equal to an allowable value, and the focus position is detected by excluding that area. Thereby, even if a high-luminance point light source exists in the focus area, the in-focus position can be accurately detected.

In order to achieve the above object, the invention according to claim 7 is a focus evaluation value acquisition means for acquiring a focus evaluation value in the entire area from the closest to infinity, and a photometric value for acquiring a photometric value in the entire area from the closest to infinity. an acquiring unit, the peak position detecting means for the focus evaluation value for detecting the position X ₀ of the peak, the minimum position detection means for photometric value to detect the lowest position X _3, before and after the focus evaluation value of the position X ₀ of the peak It gets the position _X 1, _X photometric value _Y 1 of _{2, Y 2,} compares the difference calculation means for calculating the difference [Delta] Y _1-2, the difference [Delta] Y _1-2 and allowed values alpha, difference [Delta] Y _{1- When 2} is less than the allowable value α, the focus evaluation value is set at the peak position X ₀ , and when the difference ΔY _1-2 is greater than or equal to the allowable value α, the photometric value is at the minimum position X ₃ . And a focus position setting means for setting a focus position. To provide a device.

According to the invention of claim 7, the acquired focus evaluation value throughout from close in focus evaluation value acquiring unit to infinity, the focus evaluation value at the peak position detection means positioned X ₀ of the peak is detected. Further, photometric values measured light value is obtained by the obtaining unit in the entire region from close to infinity, the photometric value is detected minimum position X ₃ at the minimum position detection means. Then, the difference calculation means calculates a difference ΔY _1-2 between the photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after the peak position X ₀ of the focus evaluation value. Focus position setting means, the difference [Delta] Y _1-2 of difference calculation means has calculated compared with the allowable value alpha, if the difference [Delta] Y _1-2 is less than the allowable value alpha, the position X ₀ of the peak focus evaluation value Set the in-focus position. On the other hand, the difference [Delta] Y _1-2 is equal to or larger than the allowable value alpha, the photometric value sets the focus position to the minimum position X _3. That is, in the present invention, even in a position where the focus evaluation value and a peak, when it difference [Delta] Y _1-2 photometry value of the position of the front and rear than the allowable value α that its position X ₀ is a pseudo by point source regarded as a peak, the photometric value sets the minimum position X ₃ to the true focus position. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

In order to achieve the above object, the invention according to claim 8 is a focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from the nearest to infinity, and a photometric value for acquiring a photometric value in the entire region from the closest to infinity. Acquisition means, peak position detection means for detecting a peak position X ₀ having a focus evaluation value, and photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ having a focus evaluation value are acquired. and its a first difference calculating means for calculating a difference [Delta] Y _1-2, the minimum position detection unit, before and after the position X ₄ of the photometric value minimum position X ₃ photometric value to detect the lowest position X _3, get the photometric value _Y 4, _{Y 5} of X _5, compares the second difference calculating means for calculating the difference _{[Delta] Y 4-5,} the difference [Delta] Y _1-2 and allowed values alpha, difference [Delta] Y _1-2 are acceptable when it is less than the value alpha, it sets the focus position the focus evaluation value at the position X ₀ of the peak, the difference Δ _1-2 is equal to or greater than the allowable value alpha, further compares the difference [Delta] Y _4-5 and tolerance beta, if the difference [Delta] Y _4-5 is less than the allowable value beta, if the photometric value to the minimum position X ₃ A focus position setting device that sets a focus position and sets a focus position at a pan focus position when the difference ΔY _4-5 is equal to or greater than an allowable value β; I will provide a.

According to the invention of claim 8, the acquired focus evaluation value throughout from close in focus evaluation value acquiring unit to infinity, the focus evaluation value at the peak position detection means positioned X ₀ of the peak is detected. Further, photometric values measured light value is obtained by the obtaining unit in the entire region from close to infinity, the photometric value is detected minimum position X ₃ at the minimum position detection means. Then, the difference [Delta] Y _1-2 position _X 1, the photometry value _Y 1 of _{X 2, Y 2} before and after the position _{X 0} of the peak focus evaluation value is calculated by the first difference calculation means, the position of the photometric value is minimum A difference ΔY _4-5 between the photometric values Y ₄ and Y ₅ of the positions X ₄ and X ₅ before and after X ₃ is calculated by the second difference calculation means. The in-focus position setting unit compares the difference ΔY _1-2 calculated by the first difference calculating unit with the allowable value α, and when the difference ΔY _1-2 is less than the allowable value α, the focus evaluation value is the peak position. to set the focus position to X _0. On the other hand, if the difference ΔY _1-2 calculated by the first difference calculation means is equal to or larger than the allowable value α, the difference ΔY _4-5 calculated by the second difference calculation means is further compared with the allowable value β, and the difference ΔY _4-5 If there is less than the allowable value beta, the photometric value sets the focus position to the minimum position X _3. When the difference ΔY _4-5 is equal to or larger than the allowable value β, the in-focus position is set as the pan focus position. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

In order to achieve the above object, the invention according to claim 9 is a focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from close to infinity, and a photometric value for acquiring a photometric value in the entire region from close to infinity. An acquisition unit, a first peak position detection unit that detects a peak position X ₀ having a focus evaluation value, and photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak evaluation value X _0. acquires a first difference calculating means for calculating the difference [Delta] Y _1-2, the minimum position detection unit photometric value to detect the lowest position X _3, the focus evaluation photometric value in the vicinity of the minimum position X ₃ a second peak position detector value for detecting the position X ₆ peak, the difference [Delta] Y _1-2 compared with allowable values alpha, if the difference [Delta] Y _1-2 is less than the allowable value alpha, a peak focus evaluation value field to set the focus position to position X _0, the difference ΔY _1-2 is equal to or greater than the permissible value α Is a focus position detecting device characterized by photometry value has and a focus position setting means for the focus evaluation value to set the focus position to the position X ₆ of the peaks near the lowest position X ₃ provide.

According to the ninth aspect of the present invention, the focus evaluation value is acquired by the focus evaluation value acquisition means in the entire area from the nearest to infinity. The position X ₀ of the focus evaluation value at the first peak position detecting means peak detection, the focus evaluation value photometric value is close to the minimum position X ₃ in the second peak position detection means detects the position X ₆ peaks The Further, photometric values measured light value is obtained by the obtaining unit in the entire region from close to infinity, the photometric value is detected minimum position X ₃ at the minimum position detection means. Then, the difference calculation means calculates the difference ΔY _1-2 between the photometric values Y ₁ and Y ₂ of the positions X ₁ and X ₂ before and after the peak position X ₀ of the focus evaluation value. The in-focus position setting unit compares the difference ΔY _1-2 calculated by the difference calculation unit with the allowable value α, and when the difference ΔY _1-2 is less than the allowable value α, the focus evaluation value is the peak position X _0. Set the in-focus position. On the other hand, when the difference [Delta] Y _1-2 is larger than the allowable value alpha, the focus evaluation value focus position to the position X ₆ of the peak of photometric values detected in the vicinity of the lowest position X ₃ in the second peak position detecting means Set. Thereby, it is possible to accurately detect the in-focus position even when a high-luminance point light source exists.

The invention according to claim 10, in order to achieve the object, the focus position setting unit, when the photometric value is not the position of the peak in the focus evaluation value in the vicinity of the minimum position X _3, the pan-focus position The in-focus position detecting device according to claim 9, wherein an in-focus position is set.

In the invention according to claim 10, in the invention according to claim 9, when the photometric value is not the position of the peak of the minimum of the focus evaluation value in the vicinity of the position X _3, pan-focus position is set to the focus position.

  According to an eleventh aspect of the present invention, in order to achieve the above object, in each of the focus areas divided into a plurality, focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from the nearest to infinity, In the area, a photometric value acquisition means for acquiring a photometric value in the entire region from close to infinity, a detection means for detecting the maximum value and the minimum value of the photometric value in each area, and a maximum value of the photometric value in each area Based on calculation means for calculating a difference from the minimum value, extraction means for extracting an area in which the difference calculated by the calculation means is an allowable value or more, and information on focus evaluation values other than the area extracted by the extraction means An in-focus position detecting device is provided that includes in-focus position detecting means for detecting the in-focus position.

  According to the eleventh aspect of the present invention, the focus evaluation value acquisition unit acquires the focus evaluation value for the entire area from the nearest to infinity, and the photometric value acquisition unit acquires the photometric value for the entire area from the closest to infinity. Is acquired. Further, the maximum and minimum photometric values in each area are detected by the detecting means, and the difference between the maximum value and the minimum value is calculated by the calculating means. Then, an area where the difference is equal to or larger than the allowable value is extracted by the extracting unit, and the in-focus position is detected by the in-focus position detecting unit based on the focus evaluation value information other than the extracted area. Thereby, even if a high-luminance point light source exists in the focus area, the in-focus position can be accurately detected.

  In order to achieve the above object, the invention according to claim 12 is the focus evaluation value acquisition means for acquiring the focus evaluation value in the entire area from the closest to infinity in each of the divided focus areas, In the area, the photometric value acquisition means for acquiring the photometric value in the entire area from the nearest to infinity, the detection means for detecting the position of the peak of the focus evaluation value in each area, the peak of the focus evaluation value of each area An in-focus position is detected based on calculation means for calculating a positional deviation amount, an extracting means for extracting an area where the deviation amount is an allowable value or more, and focus evaluation value information other than the area extracted by the extracting means. An in-focus position detecting device is provided.

  According to the twelfth aspect of the invention, in each area, the focus evaluation value acquisition unit acquires the focus evaluation value over the entire range from the nearest to infinity, and the photometric value acquisition unit acquires the photometric value over the entire range from the closest to infinity. Is done. Further, the position of the peak of the focus evaluation value in each area is detected by the detecting means, and the amount of deviation of the position of the peak of the focus evaluation value in each detected area is calculated by the calculating means. Then, an area where the amount of deviation is greater than or equal to the allowable value is extracted by the extracting means, and the in-focus position detecting means detects the in-focus position based on the focus evaluation value information other than the extracted area. Thereby, even if a high-luminance point light source exists in the focus area, the in-focus position can be accurately detected.

  According to the focus position detection method and apparatus according to the present invention, the focus position can be accurately detected even when a high-luminance point light source is present, such as during night scene photography.

  The best mode for carrying out a focus position detection method and apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an electrical configuration of a digital camera to which the present invention is applied. As shown in the figure, the digital camera 10 of the present embodiment includes a photographing optical system 12, an image sensor 14, a timing generator (TG) 16, an analog signal processing unit 18, an A / D converter 20, and an image input controller 22. , Digital signal processing unit 24, encoder 28, image display unit 30, compression / decompression processing unit 32, media controller 34, storage medium 36, AE detection unit 38, AF detection unit 40, CPU 42, ROM 44, RAM 46, flash ROM 48, operation It consists of part 50 etc.

  The overall operation of the digital camera 10 is comprehensively controlled by the CPU 42, and the CPU 42 controls each unit of the digital camera 10 according to a predetermined program based on an input from the operation unit 50.

  The operation unit 50 includes operation buttons such as a power switch, a shutter button, and a zoom button, and outputs a signal corresponding to the operation of each operation button to the CPU 42. The shutter button consists of a two-stage switch, so-called half-press and full-press. The half-press activates AE (Automatic Exposure) and AF (Auto Focus). Shooting recording is executed.

  In addition to the program executed by the CPU 42, the ROM 44 stores data necessary for various controls such as a program diagram. The CPU 42 develops the program stored in the ROM 44 in the RAM 46, and executes various processes while using the RAM 46 as a working memory. The flash ROM 48 stores various setting information relating to the operation of the digital camera 10 such as user setting information.

  The photographing optical system 12 includes a zoom lens 12z, a focus lens 12f, and a diaphragm (for example, iris diaphragm) 12i, and is operated by being driven by a zoom motor 60z, a focus motor 60f, and an iris motor 60i, respectively. That is, the zoom lens 12z is driven by the zoom motor 60z to move back and forth on the photographing optical axis, thereby changing the focal length. The focus lens 12f is driven by the focus motor 60f to move back and forth on the photographic optical axis, thereby changing the imaging position. In addition, the aperture 12i is driven by the iris motor 60i so that the opening amount changes stepwise, thereby changing the aperture value. The CPU 42 controls the driving of the zoom motor 60z, the focus motor 60f, and the iris motor 60i via the zoom motor driver 62z, the focus motor driver 62f, and the iris motor driver 62i, and performs operations of the zoom lens 12z, the focus lens 12f, and the aperture 12i. Control.

  The image sensor 14 is composed of a color CCD having a predetermined color filter array (for example, a Bayer array). Light incident on the light receiving surface of the image sensor 14 via the photographing optical system 12 is converted into signal charges in an amount corresponding to the amount of incident light by the photodiodes arranged on the light receiving surface. The signal charges accumulated in each photodiode are read according to the timing signal applied from the timing generator (TG) 16 and sequentially output from the image sensor 14 as a voltage signal (image signal).

  The analog signal processing unit 18 includes a sampling hold circuit, a color separation circuit, a gain adjustment circuit, and the like. The image signal sequentially output from the image sensor 14 is correlated double sampling (CDS) processing and color separation processing into RGB color signals. The signal level of each color signal is adjusted (pre-white balance processing).

  The A / D converter 20 converts the analog image signal output from the analog signal processing unit 18 into a digital image signal.

  The image input controller 22 includes a buffer memory having a predetermined capacity, accumulates one frame of the image signal output from the A / D converter 20, and stores it in the RAM 46.

  The digital signal processing unit 24 includes a synchronization circuit, a gamma correction circuit, a contour correction circuit, a luminance / color difference signal generation circuit, and the like, processes the image signal stored in the RAM 46 in accordance with a command from the CPU 42, and outputs the luminance signal and color difference signal A YUV signal consisting of

  When displaying a through image on the image display unit 30, images are continuously captured by the image sensor 14, and the obtained image signal is continuously processed by the digital signal processing unit 24 to generate a YUV signal. The generated YUV signal is applied to the encoder 28 via the RAM 46, converted into a signal format for display, and output to the image display unit 30. As a result, a through image is displayed on the image display unit 30.

  When an image is recorded, an image is picked up by the image pickup device 14 in accordance with a shooting command from the operation unit 50, and the obtained image signal is processed to generate a YUV signal. The generated YUV signal is added to the compression / decompression processing unit 32, converted into predetermined compressed image data (for example, JPEG), and then stored in the storage medium 36 via the media controller 34.

  The compressed image data stored in the storage medium 36 is read from the storage medium 36 in accordance with a reproduction command, converted into an uncompressed YUV signal by the compression / expansion processing unit 32, and then an image display unit via the encoder 28. 30 is output. As a result, the image recorded in the storage medium 36 is reproduced and displayed on the image display unit 30.

  The AE detection unit 38 calculates a physical quantity necessary for AE control based on an image signal obtained from the image sensor 14 in accordance with a command from the CPU 42. That is, for example, the AE detection unit 38 provides a plurality of one screens for one frame of image signals captured from the image sensor 14 via the analog signal processing unit 18, the A / D converter 20, and the image input controller 22. Area (for example, 16 × 16), and an integrated value of RGB image signals is calculated for each divided area. The CPU 42 acquires the integrated value calculated by the AE detection unit 38, detects the brightness of the subject, and calculates a photometric value (EV value). Then, the exposure (sensitivity, aperture, shutter speed) at the time of shooting is set based on the obtained EV value.

  The AF detection unit 40 calculates a physical quantity necessary for AF control based on an image signal obtained from the image sensor 14 in accordance with a command from the CPU 42. In the digital camera 10 of the present embodiment, it is assumed that AF control is performed based on the contrast of the image, and the AF detection unit 40 calculates a focus evaluation value indicating the sharpness of the image from the input image signal. As shown in FIG. 2, the AF detection unit 40 mainly includes a high-pass filter 70, an absolute value processing unit 72, a focus area extraction unit 74, and an integration unit 76. The high-pass filter 70 performs processing to pass only the high-frequency component of the G signal from the RGB image signal captured via the image input controller 22. The absolute value processing unit 72 performs processing for obtaining the absolute value of the output signal from the high-pass filter 70, and the focus area extraction unit 74 performs processing for cutting out a signal within a focus area set in advance on the screen. The integrating unit 76 integrates absolute value data in the focus area, and outputs the obtained integrated value (focus evaluation value) to the CPU 42. The CPU 42 moves the focus lens 12f, acquires focus evaluation values from the AF detection unit 40 at a plurality of detection points, and detects a focus position based on the acquired focus evaluation values. Then, the focus motor 60f is driven via the focus motor driver 62f so that the focus lens 12f moves to the obtained in-focus position.

  Processing operations at the time of shooting in the digital camera 10 of the present embodiment configured as described above are as follows.

  First, when the shutter button is half-pressed, an S1 ON signal is output from the operation unit 50 to the CPU 42. The CPU 42 executes AE and AF control in response to the S1 ON signal from the operation unit 50.

  That is, as the AE control, an image for AE is picked up by the image pickup device 14 and added to the AE detection unit 38 via the analog signal processing unit 18, the A / D converter 20, and the image input controller 22. The AE detector 38 calculates an integrated value from the input image signal and outputs the integrated value to the CPU 42. The CPU 42 detects the brightness of the subject from the integrated value obtained from the AE detector 38 and calculates the EV value. Then, the exposure is set based on the calculated EV value.

  Further, as AF control, an image for AF is picked up by the image pickup device 14 while moving the focus lens 12f, and is sent to the AF detection unit 40 via the analog signal processing unit 18, the A / D converter 20, and the image input controller 22. Add. The AF detection unit 40 calculates a focus evaluation value from the input image signal and outputs it to the CPU 42. The CPU 42 detects the focus position based on the focus evaluation value obtained from the AF detection unit 40, and drives the focus motor 60f via the focus motor driver 62f so that the focus lens 12f moves to the detected focus position. To control. A method for detecting the focus position during the AF control will be described in detail later.

  Thereafter, when the shutter button is fully pressed, an S2 ON signal is input from the operation unit 50 to the CPU 42. In response to the S2 ON signal input from the operation unit 50, the CPU 42 performs image shooting and recording processing. That is, an image for recording is picked up by the image pickup device 14, fetched into the RAM 46 via the analog signal processing unit 18, the A / D converter 20, and the image input controller 22 and added to the digital signal processing unit 24. The digital signal processing unit 24 performs necessary signal processing on the input image signal to create a YUV signal. The created YUV signal is compressed by the compression / decompression processing unit 32 and recorded in the storage medium 36 via the media controller 34.

  An image is photographed in the series of steps described above, and the photographed image is recorded in the storage medium 36. The image recorded on the storage medium 36 is read from the storage medium 36 in accordance with a reproduction instruction input from the operation unit 50, decompressed by the compression / expansion processing unit 32, and then the image display unit via the encoder 28. 30 is output. As a result, the image recorded in the storage medium 36 is reproduced and displayed on the image display unit 30.

  Next, a method for detecting a focus position in the digital camera 10 of the present embodiment will be described.

First Method In the first method, a focus evaluation value and a photometric value are obtained in the entire region from close to infinity, the position X _{0 at} which the focus evaluation value is a peak is detected, and positions X ₁ and X ₂ before and after that are detected. The photometric values Y ₁ and Y ₂ are obtained. Then, a difference ΔY _1-2 between the acquired photometric values Y ₁ and Y ₂ is calculated, and the calculated difference ΔY _1-2 is compared with an allowable value α. If the difference [Delta] Y _1-2 the calculated is less than the allowable value alpha, the focus evaluation value to set the position X ₀ of the peak in-focus position. On the other hand, the difference [Delta] Y _1-2 were calculated if allowable value α or more, the photometric value to detect the lowest position X _3, and sets the position X ₃ to the in-focus position.

  FIG. 3 is a diagram showing changes in the focus evaluation value (FIG. 3 (a)) and the photometric value (FIG. 3 (b)) from close to infinity when a high-luminance point light source does not exist in the focus area. is there.

As shown in the figure, when a high-luminance point light source does not exist in the focus area, when the focus evaluation value is obtained by moving the focus lens from the closest distance to infinity, the focus evaluation value draws one mountain. Change. Then, the position X ₀ of the peak of the mountain becomes the focus position. Before and after the focus position X _0, hardly changes photometry value.

  FIG. 4 shows a focus evaluation value from the closest to infinity (a diagram (a)), a photometric value (a diagram (b)), and a point light source when a high-luminance point light source is present in the focus area. It is a figure which shows the change of a magnitude | size (the figure (c)) and the magnitude | size of a signal level (the figure (d)).

  As shown in the figure, when a high-luminance point light source is generally present in the focus area, when a focus evaluation value is obtained by moving the focus lens from the closest distance to infinity, peaks appear at two locations. This is because a pseudo peak occurs due to the presence of the point light source. That is, when a high-luminance point light source exists in the focus area, a range in which the image signal output is saturated occurs at the point light source portion. A pseudo peak is generated in a range where the image signal output is saturated, and a peak is generated at a true in-focus position even in a range where the image signal output is not saturated. As a result, mountains appear in two places.

  Here, looking at the change in the photometric value, the photometric value changes greatly in the vicinity of the pseudo peak, whereas the peak position indicating the true in-focus position (the peak position in the range where the image signal output is not saturated) Then, the photometric value is minimum, and the photometric value hardly changes in the vicinity thereof. This is because the size of the point light source changes according to the focal position, and the size of the point light source changes greatly at the position of the pseudo peak, and as a result, the photometric value also changes greatly.

  Therefore, if the focus evaluation value detects the peak position and examines the change in the photometric value near the peak position, it can be determined whether or not the detected peak position is a pseudo peak. When the detected peak position is a pseudo peak, if the position with the smallest photometric value is set as the in-focus position, the in-focus state can be accurately obtained even when a high-luminance point light source exists in the focus area. Alignment can be performed.

Therefore, in the first method, as shown in FIG. 5, the focus evaluation value and the photometric value are obtained in the entire region from close to infinity, the focus evaluation value detects the peak position X _0, and the position X before and after that is detected. ₁ , X ₂ photometric values Y ₁ , Y ₂ are acquired, a difference ΔY _1-2 of the acquired photometric values Y ₁ , Y ₂ is calculated, the calculated difference ΔY _1-2 is compared with an allowable value α, if the difference [Delta] Y _1-2 is less than the allowable value alpha, the focus evaluation value to set the position X ₀ of the peak in-focus position. On the other hand, the difference [Delta] Y _1-2 were calculated if allowable value α or more, the photometric value to detect the lowest position X _3, and sets the position X ₃ to the in-focus position.

  FIG. 6 is a flowchart showing a processing procedure for focusing alignment by the first method.

  As described above, since the AF control is executed by half-pressing the shutter button, first, the CPU 42 detects half-pressing of the shutter button. That is, it is determined whether or not an S1 ON signal is input from the operation unit 50 (step S10).

  When the S1 ON signal is input, the CPU 42 acquires the focus evaluation value and the photometric value in the entire area from the close range to the infinity range (step S11). The acquired information on the focus evaluation value and the photometric value from the nearest to infinity is stored in the RAM 46.

Next, the CPU 42 detects the position X ₀ where the focus evaluation value is the peak based on the acquired information on the focus evaluation value and the photometric value, and the focus evaluation value is the positions X ₁ and X before and after the peak position X _{0. 2} (photometric evaluation values Y ₁ and Y at a position where the focus evaluation value is a predetermined distance Δx away from the peak position X ₀ on the closest side is X ₁ and a position a predetermined distance Δx away from the infinity side is X ₂ ) ₂ is detected (step S12).

At this time, the CPU 42 stores information on the focus evaluation value and the photometry value from close to infinity obtained as a result of photometry and distance measurement in the RAM 46, and the focus evaluation value has a peak based on the information stored in the RAM 46. position _{X 0,} the photometric value _{Y 0} of the focus evaluation value at the position _{X 0} of the peak, the photometry value _Y 1 at position _X 1, _{X 2} before and after the position _{X 0} of the peak focus evaluation value, _{Y 2} and, photometric value to detect the lowest position X _3.

Next, the difference (absolute value) ΔY _1-2 (ΔY _1-2 = | Y) between the photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the detected focus evaluation value is the peak position X _{0. 1−} Y ₂ |) is calculated (step S13). Then, the difference [Delta] Y _1-2 calculated compared with the allowable value alpha, determines the difference [Delta] Y _1-2 is whether less than the allowable value alpha (Step S14).

The allowable value α is set by obtaining an optimal numerical value for determination through experiments, simulations, and the like, and is stored in the ROM 44 in advance. CPU42 reads the allowable value α stored in the ROM 44, is compared with the difference [Delta] Y _1-2.

Is determined in step S14, when the difference [Delta] Y _1-2 is determined to less than the allowable value alpha, CPU 42 determines the position X ₀ of the peak and the true focus position the focus evaluation value, the focus and the position X ₀ The position is set (step S15). Then, the focus lens is moved to the in-focus position (step S16).

On the other hand, when the difference [Delta] Y _1-2 is determined in step S14 it is determined that the allowable value α or more, CPU 42 determines that the pseudo peak position X ₀ of the peak focus evaluation value, a photometric value detected minimum position X ₃ (Step S17). Then, the photometric value sets the minimum position X ₃ to the in-focus position (step S18). Then, the focus lens is moved to the in-focus position (step S16).

That is, even when the focus evaluation value is at the peak position as described above, when the photometric value changes greatly before and after the focus evaluation value, a high-luminance point light source exists in the focus area, and a pseudo peak is generated by the point light source. because regarded as what is occurring, in this case, the focus evaluation value is determined as not the focus position of the position X ₀ of the peak. On the other hand, at the true focus position, the photometric value hardly changes before and after that, so if a pseudo peak occurs, the position where the photometric value is the smallest is determined as the focus position, and the focus lens is at this position. Move.

  As described above, in the first method, the focus evaluation is performed after determining whether or not the position of the peak of the focus evaluation value is a pseudo peak, so that a high-luminance point light source exists in the focus area. Even in this case, it is possible to accurately perform the in-focus position alignment.

In the present embodiment, the same (step as when it first photometric value when the difference [Delta] Y _1-2 is larger than the allowable value α is detecting the lowest position X _3, the focus evaluation value for detecting the position of the peak photometric value may detect the minimum position X ₃ in S12).

Further, the positions X ₁ and X ₂ for detecting the photometric values Y ₁ and Y ₂ are obtained by setting the optimum position (the optimum range of the focus evaluation value from the peak position X ₀ ) by experiments or simulations. It is preferable.

· In the second method the first method, when the focus evaluation value position X ₀ of the peak of the pseudo peak, although the photometry value has set the minimum position X ₃ to the in-focus position, the second method So when the focus evaluation value position X ₀ of the peak of the pseudo peak, photometric value detects the minimum position X _3, examine the change in photometry value in the vicinity thereof, when the photometric value has not changed little, photometry value sets the minimum position X ₃ to the in-focus position. On the other hand, if there is a significant change, a preset pan focus position is set as the in-focus position.

Specifically, as shown in FIG. 7, the photometric value to detect the lowest position X _3, obtains the photometric value Y _4, Y ₅ position X _4, X ₅ before and after, the difference (absolute value ) ΔY _4-5 (ΔY _4-5 = | Y ₄ −Y ₅ |) is calculated. Then, the calculated difference ΔY _4-5 is compared with the allowable value β, and it is determined whether or not the difference ΔY _4-5 is less than the allowable value β. If the difference [Delta] Y _4-5 is less than the allowable value beta, it sets the photometric value is the minimum position X ₃ to the in-focus position, if the difference [Delta] Y _4-5 are allowable value beta or pan focus preset Set the position to the in-focus position.

  FIG. 8 is a flowchart showing a processing procedure for focusing alignment by the second method. In addition, the same code | symbol is attached | subjected about the process same as a 1st method.

  First, the CPU 42 detects a half-press of the shutter button. That is, it is determined whether or not an S1 ON signal is input (step S10).

When the S1 ON signal is input, the CPU 42 acquires the focus evaluation value and the photometric value in the entire area from the close range to the infinity range (step S11). Then, to detect the position _{X 0} of the peak focus evaluation value, for detecting photometric values _Y 1, _{Y 2} at position _X 1, _{X 2} before and after (step S12).

Next, the difference (absolute value) ΔY _1-2 (ΔY _1-2 = | Y) between the photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the detected focus evaluation value is the peak position X _{0. 1−} Y ₂ |) is calculated (step S13). Then, the difference [Delta] Y _1-2 calculated compared with the allowable value alpha, determines the difference [Delta] Y _1-2 is whether less than the allowable value alpha (Step S14).

As a result of the determination, when the difference [Delta] Y _1-2 is determined to less than the allowable value alpha, CPU 42 has the position X ₀ of the peak focus evaluation value is determined as the true focus position, the position X ₀ to the focus position Set (step S15). Then, the focus lens is moved to the in-focus position (step S16).

On the other hand, when the difference [Delta] Y _1-2 is determined that the allowable value α or more is determined in step S14, CPU 42 is the focus evaluation value to determine the position _{X 0} of the peak and quasi-peak. Then, the photometric value to detect the lowest position _{X 3} (step S20), and the position a predetermined distance away Δx from the position _X 4, _{X 5} (photometric value minimum position _{X 3} before and after the near side and _{X 4} Then, photometric values Y ₄ and Y ₅ at a position separated by a predetermined distance Δx on the infinity side are defined as X ₅ (step S21).

The CPU 42 calculates a difference (absolute value) ΔY _4-5 (ΔY _4-5 = | Y ₄ −Y ₅ |) between the detected photometric values Y ₄ and Y ₅ (step S22), and calculates the calculated difference ΔY _{4− 5} is compared with the allowable value β, and it is determined whether or not the difference ΔY _4-5 is less than the allowable value β (step S23).

As with the allowable value α, the allowable value β is obtained by setting an optimal numerical value for determination through experiments, simulations, or the like, and is stored in the ROM 44 in advance. The CPU 42 reads the allowable value β stored in the ROM 44 and compares it with the difference ΔY _4-5 .

The result of this determination, the difference [Delta] Y _4-5 is if less than the allowable value beta, the photometric value sets the minimum position X ₃ to the in-focus position (step S24). On the other hand, if the difference ΔY _4-5 is greater than or equal to the allowable value β, a preset pan focus position is set as the in-focus position (step S25). Then, the focus lens is moved to the set focus position (step S16).

As described above, in the second method, when the focus evaluation value peak positions are pseudo peak, photometric value detects the minimum position X _3, examine the change in photometry value in the vicinity thereof, the photometric value is almost if not changed, and sets the minimum position X ₃ photometric value to the in-focus position, if the large change so set the pan-focus position set in advance in the focus position more precisely focused Alignment can be performed.

In this example, the same steps as when it first photometric value when the difference [Delta] Y _1-2 is larger than the allowable value α is detecting the lowest position X _3, the focus evaluation value for detecting the position of the peak ( In step S12), the photometric values Y ₄ and Y ₅ at the position X ₃ having the smallest photometric value and the positions X ₄ and X ₅ before and after the position X ₃ may be detected.

  Moreover, although the allowable value α and the allowable value β are set separately, the allowable value α and the allowable value β may be the same value.

- In the third method the first method, when the focus evaluation value is the position X ₀ of the peak of the pseudo peak, although the photometry value has set the minimum position X ₃ to the in-focus position, the third method in, as shown in FIG. 9, when the focus evaluation value position X ₀ of the peak of the pseudo peak, photometric value detects the minimum position X _3, the focus evaluation value in the vicinity thereof to detect the position X ₆ peaks Then, the position is set as the in-focus position.

  FIG. 10 is a flowchart showing a processing procedure for focusing alignment by the third method. In addition, the same code | symbol is attached | subjected about the process same as a 1st method.

  First, the CPU 42 detects a half-press of the shutter button. That is, it is determined whether or not an S1 ON signal is input (step S10).

When the S1 ON signal is input, the CPU 42 acquires the focus evaluation value and the photometric value in the entire area from the close range to the infinity range (step S11). Then, to detect the position _{X 0} of the peak focus evaluation value, for detecting photometric values _Y 1, _{Y 2} at position _X 1, _{X 2} before and after (step S12).

Next, the difference (absolute value) ΔY _1-2 (ΔY _1-2 = | Y) between the photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the detected focus evaluation value is the peak position X _{0. 1−} Y ₂ |) is calculated (step S13), and the calculated difference ΔY _1-2 is compared with the allowable value α. Then, it is determined whether the difference [Delta] Y _1-2 are allowable value α or more (step S14).

As a result of the determination, when the difference [Delta] Y _1-2 is determined to less than the allowable value alpha, CPU 42 has the position X ₀ of the peak focus evaluation value is determined as the true focus position, the position X ₀ to the focus position Set (step S15). Then, the focus lens is moved to the in-focus position (step S16).

On the other hand, when the difference [Delta] Y _1-2 is determined that the allowable value α or more is determined in step S14, CPU 42 is the focus evaluation value to determine the position _{X 0} of the peak and quasi-peak. Then, the photometric value to detect the lowest position _{X 3} (step S30), near its focus evaluation value for detecting the position _{X 6} peaks (step S31).

Here, the search range of the focus evaluation value, it is assumed that the photometric value is set to a narrow range apart a small distance Δd in front and rear from the minimum position X _3, detected focus evaluation value within that range the position X ₆ peaks To do.

The results of this search, CPU 42 is the focus evaluation value determines the presence or absence of the position _{X 6} peaks (step S32). When the focus evaluation value determining that there is a position X ₆ peak, CPU 42, the focus evaluation value is set to the position X ₆ peaks focus position (step S33). On the other hand, the focus evaluation value when it is determined that there is no position X ₆ peak, CPU 42 sets in advance the pan-focus position in the focus position (step S34). Then, the focus lens is moved to the set focus position (step S16).

As described above, in the third method, when the focus evaluation value peak positions are pseudo peak, photometric value detects the minimum position X _3, near its focus evaluation value detection position X ₆ peaks and, since setting a position X ₆ detected in-focus position, it is possible to perform combined and more accurate focus position.

Incidentally, the same steps as when in this example and the first photometric value when the difference [Delta] Y _1-2 is larger than the allowable value α is detecting the lowest position X _3, the focus evaluation value for detecting the position X ₀ of the peak In step S12, the position X ₃ having the smallest photometric value and the position X ₆ having the peak focus evaluation value in the vicinity thereof may be detected.

The position X ₆ peaks focus evaluation value may be detected on the basis of the information of the first focus evaluation value of the acquired whole, the process of detecting the focus evaluation value photometric value is in the vicinity of the minimum position again executed (moving the focus lens photometric value in the vicinity of the minimum position, and acquires the focus evaluation value), it may detect the peak position X ₆ based on the information of the obtained focus evaluation values.

-Fourth method In the fourth method, the focus area is divided into a plurality of areas, and focus evaluation values and photometric values are obtained over the entire area from the nearest to infinity for each divided area. Detect maximum and minimum values. Then, a difference between the maximum value and the minimum value is calculated, and an in-focus position is detected by excluding an area where the calculated difference is an allowable value or more. That is, in the present invention, it is assumed that a high-brightness point light source exists in an area where the difference between the maximum value and the minimum value of the photometric value is an allowable value or more, and the in-focus position is detected by excluding that area. .

  For example, as shown in FIG. 11, a focus area is set at the center of the screen, and the focus area is divided into four and divided into four. Assume that the divided areas are areas A, B, C, and D, and a high-brightness point light source exists in area B.

  For each area A, B, C, and D, when focus evaluation values are acquired in the entire region from close to infinity, the focus evaluation values in each area change as shown in FIG. 12, for example. In this case, a pseudo peak occurs in area B having a point light source.

  Further, when the focus evaluation values of the four areas A, B, C, and D are averaged, the focus evaluation value changes as shown in FIG. In this case, since the area B is included, the average focus evaluation value also has a pseudo peak due to the influence of the pseudo peak in the area B. If focus position detection is performed based on the average focus evaluation value, the pseudo peak is regarded as the focus position, and a defocused photograph is taken.

  On the other hand, when the focus evaluation values of the remaining three areas A, C, and D excluding the area B are averaged, the focus evaluation value changes as shown in FIG. In this case, since it is not influenced by the pseudo peak due to the point light source, the position of the peak of the focus evaluation value can be regarded as the in-focus position.

  Therefore, when the focus position is detected based on the focus evaluation value of each divided area, it is necessary to exclude the area including the point light source.

  Here, for each of the areas A, B, C, and D, when the photometric value is acquired in the entire area from the close range to the infinity, the photometric value changes as shown in FIG. 14, for example. That is, the photometric value changes greatly in area B having a high-luminance point light source. This is because the size of the point light source changes as the focal position changes, and as a result, the photometric value also changes greatly.

  Therefore, if a photometric value is acquired for the entire area from close to infinity and the change is examined, it can be determined whether or not a point light source is included in each area.

  Therefore, in the fourth method, for each divided area, photometric values are obtained in the entire area from the nearest to infinity, the maximum and minimum photometric values in each area are detected, and the difference is obtained and obtained. An in-focus position is detected by excluding an area where the difference is greater than or equal to an allowable value. Thereby, it is possible to accurately detect the in-focus position without being affected by the point light source.

  FIG. 15 is a flowchart showing a processing procedure for in-focus position alignment according to the fourth method.

  First, the CPU 42 detects a half-press of the shutter button. That is, it is determined whether or not an S1 ON signal is input (step S40).

  When the S1 ON signal is input, the CPU 42 acquires a focus evaluation value and a photometric value for each of the areas A, B, C, and D in the entire area from the nearest to infinity (step S41). Information about the obtained focus evaluation values and photometric values of the areas A, B, C, and D is stored in the RAM 46.

Next, the CPU 42 determines the maximum photometric values A _MAX , B _MAX , C _MAX in the areas A, B, C, D based on the acquired photometric value information of the areas A, B, C, D. D _MAX and the minimum values A _MIN , B _MIN , C _MIN , and D _MIN are detected (step S42). Then, the difference (absolute value) between the maximum photometric value A _MAX , B _MAX , C _MAX , D _MAX and the minimum value A _MIN , B _MIN , C _MIN , D _MIN in each detected area A, B, C, D. _{| a MAX -A MIN |, |} B MAX -B MIN |, | C MAX -C MIN |, | D MAX -D MIN | is calculated (step S43).

Then, CPU 42 is the difference between the maximum value _{A MAX} and the minimum value _{A MIN} of the photometric value in the area A _| A MAX _{-A MIN |} is compared with specified tolerance gamma, the difference _| A MAX _{-A MIN |} permissible It is determined whether or not the value is less than γ (step S43).

Note that the allowable value γ is set by obtaining an optimal value for determination through experiments, simulations, or the like, and is stored in the ROM 44 in advance. The CPU 42 reads the allowable value γ stored in the ROM 44 and compares it with the difference | A _MAX −A _MIN |.

As a result of this determination, if it is determined that the difference | A _MAX −A _MIN | is greater than or equal to the allowable value γ, the CPU 42 excludes the area A from focus position detection to be performed later (step S44). That is, focus position detection is performed without using information on the focus evaluation value of area A.

On the other hand, if it is determined that the difference | A _MAX −A _MIN | is less than the allowable value γ, then the CPU 42 determines the difference | B _MAX −B between the maximum photometric value B _MAX and the minimum value B _{MIN in} the area B. _MIN | is compared with a prescribed allowable value γ, and it is determined whether or not the difference | B _MAX −B _MIN | is less than the allowable value γ (step S45).

As a result of this determination, if it is determined that the difference | B _MAX −B _MIN | is greater than or equal to the allowable value γ, the CPU 42 excludes the area B from focus position detection to be performed later (step S46).

On the other hand, if it is determined that the difference | B _MAX −B _MIN | is less than the allowable value γ, the CPU 42 then determines the difference | C _MAX −C between the maximum photometric value C _MAX and the minimum value C _{MIN in} the area C. _MIN | is compared with a prescribed allowable value γ, and it is determined whether or not the difference | C _MAX −C _MIN | is less than the allowable value γ (step S47).

As a result of this determination, if the difference | C _MAX −C _MIN | is determined to be greater than or equal to the allowable value γ, the CPU 42 excludes the area C from focus position detection to be performed later (step S48).

On the other hand, if it is determined that the difference | C _MAX −C _MIN | is less than the allowable value γ, then the CPU 42 determines the difference | D _MAX −D between the maximum photometric value D _MAX and the minimum value D _{MIN in} the area D. _MIN | is compared with a prescribed allowable value γ, and it is determined whether or not the difference | D _MAX −D _MIN | is less than the allowable value γ (step S49).

As a result of this determination, if it is determined that the difference | D _MAX −D _MIN | is greater than or equal to the allowable value γ, the CPU 42 excludes the area D from focus position detection to be performed later (step S50).

As described above, for all areas A, B, C, and D, the difference between the maximum and minimum photometric values is compared with the allowable value, and the area where the difference is equal to or larger than the allowable value is excluded from the focus position detection. Then, the focus position is detected using the focus evaluation value information of the remaining areas that are not excluded (step S51). That is, for example, in the area B, if the difference | B _MAX −B _MIN | of the photometric value maximum value B _MAX and the minimum value B _MIN is equal to or larger than the allowable value γ, the area B is excluded from the focus position detection. In-focus position detection is performed based on the focus evaluation value information of the remaining areas A, C, and D. Further, for example, in areas B and C, if the difference between the maximum and minimum photometric values is greater than or equal to the allowable value, area B and area C are excluded from in-focus position detection, so the remaining areas A and D The focus position is detected based on the information of the focus evaluation value.

  Here, in the focus position detection, the focus evaluation values of the remaining areas that are not excluded are averaged, and the peak position of the averaged focus evaluation value is detected. Then, the focus lens is moved to the in-focus position thus determined, and the in-focus position is adjusted (step S52).

  As described above, in the fourth method, since the focus position is detected by excluding the area where the point light source exists, the focus position can be accurately adjusted even when the point light source exists in the focus area. Can do.

  In this example, when the focus position is detected, the focus evaluation values of the remaining areas that are not excluded are averaged, and the peak position of the average focus evaluation value is detected, but the focus position is detected. The method is not limited to this. For example, the focus evaluation value may be detected by detecting the peak position of the focus evaluation value for each area and averaging the peak positions. Further, the focus area may be moved.

  In this example, the focus area is set to the center and the inside of the focus area is divided into four. However, the focus area setting method and the focus area dividing method are particularly limited. It is not a thing. For example, the entire screen may be a focus area and may be divided into 64 by 8 × 8.

  In this example, the area where the point light source exists is excluded, and the focus position is detected based on the focus evaluation value information of the remaining area. However, the focus position is detected based on the focus evaluation value information of the remaining area. If the camera cannot be detected, the pan focus position may be set to the in-focus position.

-Fifth method In the fifth method, the focus area is divided into a plurality of areas, and focus evaluation values are obtained for the divided areas from the nearest to infinity, and the peak position of the focus evaluation value in each area is obtained. To detect. Then, the shift amount of the peak position between the areas is calculated, and the in-focus position is detected by excluding the area where the shift amount is equal to or larger than the allowable value. That is, in the fifth method, it is considered that a high-luminance point light source exists in an area where the deviation amount of the peak position of the focus evaluation value is equal to or larger than the allowable value, and the focus position is detected by excluding that area. Do.

  For example, as shown in FIG. 16, a focus area is set at the center of the screen, and the focus area is divided into three. Assume that the divided areas are areas A, B, and C, and that a high-luminance point light source exists in area C.

  For each area A, B, and C, when focus evaluation values are acquired in the entire region from close to infinity, the focus evaluation values in each area change, for example, as shown in FIG. In this case, a pseudo peak occurs in area C having a point light source.

  Further, when the focus evaluation values of the three areas A, B, and C are averaged, the focus evaluation value changes as shown in FIG. In this case, since the area C is included, it is affected by the pseudo peak in the area C, and the average focus evaluation value also generates the pseudo peak. If focus position detection is performed based on the average focus evaluation value, the pseudo peak is regarded as the focus position, and a defocused photograph is taken.

  On the other hand, when the focus evaluation values of the remaining two areas A and B excluding the area C are averaged, the focus evaluation value changes as shown in FIG. In this case, since it is not influenced by the pseudo peak due to the point light source, the position of the peak of the focus evaluation value can be regarded as the in-focus position.

  Therefore, when the focus position is detected based on the focus evaluation value of each divided area, it is necessary to exclude the area including the point light source.

Here, for each of the areas A, B, and C, when the focus evaluation values of the peak positions X _A , X _B , and X _C are compared, the peak position X _{C of the} area C having the point light source is as shown in FIG. , Greatly deviate from the peak positions X _A and X _B in other areas.

Therefore, for each of the areas A, B, and C, the position X _A , X _B , and X _{C at} which the focus evaluation value is a peak is obtained, the positions are compared, and an area that greatly deviates is detected. can do.

  Therefore, in the fifth method, the position of the peak of the focus evaluation value is detected for each divided area, the shift amount of the peak position between the areas is calculated, the area including the point light source is obtained, and the obtained area And the in-focus position is detected. Thereby, it is possible to accurately detect the in-focus position without being affected by the point light source.

  FIG. 20 is a flowchart illustrating a processing procedure for in-focus position alignment according to the fifth method.

  First, the CPU 42 detects a half-press of the shutter button. That is, it is determined whether or not an S1 ON signal is input (step S60).

  When the S1 ON signal is input, the CPU 42 acquires focus evaluation values for the areas A, B, and C from the closest range to the infinity range (step S61). Information about the obtained focus evaluation values of the areas A, B, and C is stored in the RAM 46.

Next, the CPU 42 detects positions X _A , X _B , and X _C at which the focus evaluation values are peaks based on the acquired information on the focus evaluation values of the areas A, B, and C (step S62). Then, deviation amounts (absolute values) X _AB , X _BC , X _CA of the detected peak positions of the areas A, B, C are calculated (step S63).

Next, the CPU 42 compares the calculated deviation amounts X _AB , X _BC , X _CA of the peak positions between the respective areas with a prescribed allowable value δ, and the deviation amounts X _AB , X _BC , X _CA are all allowable. It is determined whether or not a condition that the value is less than δ (X _AB <δ, X _BC <δ, and X _CA <δ) is satisfied (step S64).

The allowable value δ is set by obtaining an optimal numerical value for determination through experiments or simulations, and is stored in the ROM 44 in advance. The CPU 42 reads the allowable value δ stored in the ROM 44 and compares it with the deviation amounts X _AB , X _BC , X _CA.

As a result of this determination, if it is determined that the deviation amounts X _AB , X _BC , X _CA all satisfy the condition of less than the allowable value δ, the CPU 42 does not have a high-luminance point light source in each area A, B, C. The focus position is detected based on the focus evaluation value information of all areas (step S65).

  Here, in the focus position detection, the focus evaluation values of the remaining areas that are not excluded are averaged, and the peak position of the averaged focus evaluation value is detected. Then, the focus lens is moved to the in-focus position thus obtained, and the in-focus position is adjusted (step S66).

On the other hand, if it is determined in step S64 that each of the deviation amounts X _AB , X _BC , X _CA does not satisfy the condition that it is less than the allowable value δ, the CPU 42 then makes a deviation amount X _AB and a deviation amount X _BC. Is determined to satisfy the condition that X is greater than or equal to the allowable value δ and the deviation amount X _CA is less than the allowable value δ (X _AB ≧ δ, X _BC ≧ δ, and X _CA <δ) (step) S67).

As a result of this determination, if it is determined that the deviation amount X _AB and the deviation amount X _BC are greater than or equal to the allowable value δ and the deviation amount X _CA is less than the allowable value δ, the CPU 42 It is determined that a light source is present, and area B is excluded from focus position detection (step S68). Then, the focus position is detected based on the focus evaluation value information of areas other than area B, that is, areas A and C (step S65), the focus lens is moved to the obtained focus position, and the focus position is adjusted. This is performed (step S66).

On the other hand, if it is determined that the condition that the deviation amount X _AB and the deviation amount X _BC are equal to or larger than the allowable value δ and the deviation amount X _CA is less than the allowable value δ, then the CPU 42 determines that the deviation amount X _AB is not satisfied. Is less than the allowable value δ, and the condition (X _AB <δ and X _BC ≧ δ and X _CA ≧ δ) that the deviation amount X _BC and the deviation amount X _CA are greater than or equal to the tolerance value δ is satisfied. (Step S69).

As a result of this determination, if it is determined that the deviation amount X _AB is less than the allowable value δ and the deviation amount X _BC and the deviation amount X _CA satisfy the allowable value δ or more, the CPU 42 determines that the area C has a high brightness point. It is determined that a light source is present, and area C is excluded from focus position detection (step S70). Then, the focus position is detected based on the focus evaluation value information of areas other than area C, that is, areas A and B (step S65), the focus lens is moved to the obtained focus position, and the focus position is adjusted. This is performed (step S66).

On the other hand, if it is determined that the condition that the deviation amount X _AB is less than the allowable value δ and the deviation amount X _BC and the deviation amount X _CA are not less than the allowable value δ is satisfied, the CPU 42 It is determined that there is a light source, and area A is excluded from focus position detection (step S71). That is, in this case, less than the deviation amount X _BC allowable value [delta], and, since the deviation amount X _AB and amount of deviation X _CA becomes the allowable value [delta] above, CPU 42 is a high brightness point source is located in the area A The area A is excluded from the focus position detection (step S71). Then, the focus position is detected based on the focus evaluation value information of areas other than area C, that is, areas A and B (step S65), the focus lens is moved to the obtained focus position, and the focus position is adjusted. This is performed (step S66).

  As described above, in the fifth method, since the focus position is detected by excluding the area where the point light source exists, the focus position can be accurately adjusted even when the point light source exists in the focus area. Can do.

  In this example, when the focus position is detected, the focus evaluation values of the remaining areas that are not excluded are averaged, and the peak position of the average focus evaluation value is detected, but the focus position is detected. The method is not limited to this. For example, the focus evaluation value may be detected by detecting the peak position of the focus evaluation value for each area and averaging the peak positions.

  In this example, the focus area is set at the center, and the focus area is divided into three. However, the focus area setting method and the focus area dividing method are particularly limited. It is not a thing. For example, the entire screen may be a focus area and may be divided into 64 by 8 × 8. Further, the focus area may be moved.

  In this example, the area where the point light source exists is excluded, and the focus position is detected based on the focus evaluation value information of the remaining area. However, the focus position is detected based on the focus evaluation value information of the remaining area. If the camera cannot be detected, the pan focus position may be set to the in-focus position.

  As described above, according to the focus position detection method and apparatus according to the present invention, it is possible to accurately perform focus position adjustment even when a high-luminance point light source exists in the focus area.

  In the above embodiment, the case where the present invention is applied to a digital camera has been described as an example. However, the application of the present invention is not limited to this. As long as the in-focus position is detected by the contrast detection method, the present invention can be applied to all photographing apparatuses.

1 is a block diagram showing an electrical configuration of a digital camera to which the present invention is applied. Block diagram showing the configuration of the AF detection unit The figure which shows the change of the focus evaluation value (a) and the photometry value (b) from the nearest to infinity when a high-luminance point light source does not exist in a focus area. Focus evaluation value (a), photometry value (b), point light source size (c), and signal level from close to infinity when a high-luminance point light source is present in the focus area The figure which shows the change of (d) The figure which shows the change of the focus evaluation value (a) and the photometry value (b) from the nearest to infinity when a high-luminance point light source exists in a focus area. The flowchart which shows the process sequence of the focusing position alignment by a 1st method The figure which shows the change of the focus evaluation value (a) and the photometry value (b) from the nearest to infinity when a high-luminance point light source exists in a focus area. The flowchart which shows the process sequence of the focusing position alignment by a 2nd method The figure which shows the change of the focus evaluation value (a) and the photometry value (b) from the nearest to infinity when a high-luminance point light source exists in a focus area. The flowchart which shows the process sequence of the focusing position alignment by a 3rd method Illustration of focus area division method The figure which shows the change of the focus evaluation value of each divided area The figure which shows the change of the focus evaluation value of the time (a) which averaged all the areas, and the time (b) which excluded and averaged the area containing a point light source The figure which shows the change of the photometric value of each divided area The flowchart which shows the process sequence of the focusing position alignment by a 4th method Illustration of focus area division method The figure which shows the change of the focus evaluation value of each divided area The figure which shows the change of the focus evaluation value of the time (a) which averaged all the areas, and the time (b) which excluded and averaged the area containing a point light source Explanatory drawing of the comparison method of the peak position of the focus evaluation value between each area The flowchart which shows the process sequence of the focusing position alignment by a 5th method

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Digital camera, 12 ... Imaging optical system, 12z ... Zoom lens, 12f ... Focus lens, 12i ... Aperture, 14 ... Image sensor, 16 ... Timing generator (TG), 18 ... Analog signal processing part, 20 ... A / D Converter: 22 ... Image input controller, 24 ... Digital signal processing unit, 28 ... Encoder, 30 ... Image display unit, 32 ... Compression / decompression processing unit, 34 ... Media controller, 36 ... Storage medium, 38 ... AE detection unit, 40 ... AF detection unit, 42 ... CPU, 44 ... ROM, 46 ... RAM, 48 ... flash ROM, 50 ... operation unit, 60z ... zoom motor, 60f ... focus motor, 60i ... iris motor, 62z ... zoom motor driver, 62f ... Focus motor driver, 62i ... Iris motor driver, 70 ... High pass Motor, 72 ... absolute value processing unit, 74 ... focus area extraction unit, 76 ... integrating unit

Claims (12)

Focus evaluation values and photometric values are obtained in the entire area from close to infinity,
Focus evaluation value is detected the position X ₀ of the peak,
The focus evaluation values obtain photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ ,
The difference ΔY _1-2 between the obtained photometric values Y ₁ and Y ₂ is calculated,
Compare the calculated difference ΔY _1-2 with the tolerance α,
If the difference [Delta] Y _1-2 the calculated is less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peak,
If the difference [Delta] Y _1-2 the calculated allowable value α or more, the photometric value to detect the lowest position X _3, focus position detection, characterized in that the photometric value is the lowest position X ₃ and focus position Method. Focus evaluation values and photometric values are obtained in the entire area from close to infinity,
Focus evaluation value is detected the position X ₀ of the peak,
The focus evaluation values obtain photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ ,
The difference ΔY _1-2 between the obtained photometric values Y ₁ and Y ₂ is calculated,
Compare the calculated difference ΔY _1-2 with the tolerance α,
If the difference [Delta] Y _1-2 the calculated is less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peaks,
If calculated difference [Delta] Y _1-2 was allowable value α or more, the photometric value to detect the lowest position X _3,
Obtain photometric values Y ₄ and Y ₅ at positions X ₄ and X ₅ before and after the position X ₃ having the smallest photometric value,
The difference ΔY _4-5 between the obtained photometric values Y ₄ and Y ₅ is calculated,
Compare the calculated difference ΔY _4-5 with the allowable value β,
If the calculated difference ΔY _4-5 is less than the allowable value β, the position X ₃ with the smallest photometric value is set as the in-focus position,
If the calculated difference ΔY _4-5 is greater than or equal to the allowable value β, the focus position detection method is characterized in that the pan focus position is set as the focus position. Focus evaluation values and photometric values are obtained in the entire area from close to infinity,
Focus evaluation value is detected the position X ₀ of the peak,
The focus evaluation values obtain photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ ,
The difference ΔY _1-2 between the obtained photometric values Y ₁ and Y ₂ is calculated,
Compare the calculated difference ΔY _1-2 with the tolerance α,
If the difference [Delta] Y _1-2 the calculated is less than the allowable value alpha, the focus evaluation value and the focus position of the position X ₀ of the peak,
If calculated difference [Delta] Y _1-2 was allowable value α or more, the photometric value to detect the lowest position X _3,
Focus evaluation value in the vicinity of the photometric value of the minimum position X ₃ detects the position X ₆ peaks,
Focus position detecting method characterized by the focus evaluation value and focus position of the position X ₆ peak. If the photometric value is not the position of the peak in the focus evaluation value in the vicinity of the minimum position X _3, focus position detection method according to claim 3, characterized in that the focus position of the pan-focus position. Focus position that divides the focus area into multiple areas, obtains the focus evaluation value for each area from the nearest to infinity, and detects the focus position based on the obtained focus evaluation value information for each area In the detection method,
Focus evaluation values and photometric values are obtained for each area from close to infinity,
Detect the maximum and minimum photometric values in each area,
Calculate the difference between the maximum and minimum photometric values in each area,
An in-focus position detection method comprising: detecting an in-focus position by excluding information on a focus evaluation value of an area where the calculated difference is equal to or greater than an allowable value. Focus position that divides the focus area into multiple areas, obtains the focus evaluation value for each area from the nearest to infinity, and detects the focus position based on the obtained focus evaluation value information for each area In the detection method,
For each area, obtain focus evaluation values from close to infinity,
Detect the peak position of the focus evaluation value in each area,
Calculate the deviation of the peak position of the focus evaluation value between each area,
An in-focus position detection method comprising: detecting an in-focus position by excluding information on a focus evaluation value of an area where a deviation amount is an allowable value or more. A focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from close to infinity,
A photometric value acquisition means for acquiring a photometric value in the entire region from close to infinity,
A peak position detecting means for detecting the position X ₀ of the peak as the focus evaluation value;
And the minimum position detection unit photometric value to detect the lowest position X _3,
A difference calculation means for obtaining photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ of the focus evaluation value, and calculating a difference ΔY _1-2 thereof;
The difference [Delta] Y _1-2 compared with allowable values alpha, if the difference [Delta] Y _1-2 is less than the allowable value alpha, sets the focus position the focus evaluation value at the position _{X 0} of the peak, the difference [Delta] Y _1-2 is If exceeding the allowable value α is, the focus position setting means for photometric value sets the focus position to the minimum position X _3,
An in-focus position detecting device comprising: A focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from close to infinity,
A photometric value acquisition means for acquiring a photometric value in the entire region from close to infinity,
A peak position detecting means for detecting the position X ₀ of the peak as the focus evaluation value;
First difference calculation means for obtaining photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ of the focus evaluation value, and calculating a difference ΔY _1-2 thereof;
And the minimum position detection unit photometric value to detect the lowest position X _3,
Second difference calculation means for obtaining photometric values Y ₄ and Y ₅ at positions X ₄ and X ₅ before and after the position X ₃ having the smallest photometric value, and calculating a difference ΔY _4-5 ;
The difference [Delta] Y _1-2 compared with allowable values alpha, if the difference [Delta] Y _1-2 is less than the allowable value alpha, sets the focus position the focus evaluation value at the position _{X 0} of the peak, the difference [Delta] Y _1-2 is If exceeding the allowable value α is further compares the difference [Delta] Y _4-5 and tolerance beta, when the difference [Delta] Y _4-5 is less than the permissible value beta is set to focus position photometric value to the minimum position X ₃ If the difference ΔY _4-5 is greater than or equal to the allowable value β, the focus position setting means for setting the focus position at the pan focus position;
An in-focus position detecting device comprising: A focus evaluation value acquisition means for acquiring a focus evaluation value in the entire region from close to infinity,
A photometric value acquisition means for acquiring a photometric value in the entire region from close to infinity,
A first peak position detecting means for the focus evaluation value for detecting the position X ₀ of the peak,
First difference calculation means for obtaining photometric values Y ₁ and Y ₂ at positions X ₁ and X ₂ before and after the peak position X ₀ of the focus evaluation value, and calculating a difference ΔY _1-2 thereof;
And the minimum position detection unit photometric value to detect the lowest position X _3,
A second peak position detecting means for the focus evaluation value in the vicinity of the photometric value of the minimum position X ₃ detects the position X ₆ peaks,
The difference [Delta] Y _1-2 compared with allowable values alpha, if the difference [Delta] Y _1-2 is less than the allowable value alpha, sets the focus position the focus evaluation value at the position _{X 0} of the peak, the difference [Delta] Y _1-2 is If exceeding the allowable value α is, the focus position setting means for photometric value sets the focus position to the position X ₆ peaks focus evaluation value in the vicinity of the minimum position X _3,
An in-focus position detecting device comprising: The focus position setting unit, when the photometric value is not the position of the peak in the focus evaluation value in the vicinity of the minimum position X _3, claim 9, characterized in that to set the focus position to the pan-focus position In-focus position detection device. In each of the focus areas divided into a plurality of areas, a focus evaluation value acquisition means for acquiring a focus evaluation value in the entire area from the nearest to infinity,
In each area, a photometric value acquisition means for acquiring a photometric value in the entire area from close to infinity,
Detection means for detecting the maximum and minimum photometric values in each area;
An arithmetic means for calculating a difference between the maximum and minimum photometric values in each area;
Extracting means for extracting an area where the difference calculated by the calculating means is equal to or greater than an allowable value;
A focus position detection means for detecting a focus position based on information of a focus evaluation value other than the area extracted by the extraction means;
An in-focus position detecting device comprising: In each of the focus areas divided into a plurality of areas, a focus evaluation value acquisition means for acquiring a focus evaluation value in the entire area from the nearest to infinity,
In each area, a photometric value acquisition means for acquiring a photometric value in the entire area from close to infinity,
Detecting means for detecting a position of a peak of the focus evaluation value in each area;
A calculation means for calculating a shift amount of a peak position of the focus evaluation value between the areas;
An extraction means for extracting an area where the deviation amount is equal to or greater than an allowable value;
A focus position detection means for detecting a focus position based on information of a focus evaluation value other than the area extracted by the extraction means;
An in-focus position detecting device comprising:

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