JP6916419B2 - Focus adjuster - Google Patents

Description

The present invention relates to a focus adjusting device.

In a camera that applies the phase difference detection method to focus detection, when a distant subject and a near subject compete with each other in the shooting screen, the focus detection signal sequence used for the calculation of the distance measuring sensor is divided in advance. , There is a technique for detecting the amount of defocus of an arbitrary subject among a distant subject and a near subject.

Japanese Unexamined Patent Publication No. 6-82686

According to Patent Document 1, the focus detection pixel sequence is divided into a plurality of blocks, but the block boundaries do not always match the boundaries of the perspective competing subjects, so that a focus detection error may occur.

According to the first aspect of the present invention, the focus adjusting device receives a lens in which light passing through an optical system forming an image of a subject is incident and light transmitted through the lens and outputs a first signal. A detection unit having a plurality of sensors including a light receiving unit, a second light receiving unit that receives light transmitted through the lens and outputs a second signal, a first signal train composed of the plurality of first signals, and a plurality of the above. The first deviation amount from the second signal train composed of the second signal is calculated, and based on the difference value between the first signal train and the second signal train that are relatively shifted by the first deviation amount. There, the control for controlling a calculation unit for calculating a second deviation between said second signal sequence and the first signal sequence, the optical system on the basis of the second shift amount calculated by the calculation unit It has a part and.
According to a second aspect of the present invention, the focus adjusting device receives a plurality of first light receiving light that has passed through a first region of an optical system that forms an image of a subject and outputs a plurality of first signals. A detection unit having a unit, a plurality of second light receiving units that receive light that has passed through a second region of the optical system and output a plurality of second signals, and the plurality of first signals and the plurality of units. The first signal with respect to the second signal of the above is calculated, and the plurality of first signals and the plurality of second signals are relatively shifted by the amount of the first deviation, and the plurality of first signals are calculated. Based on the difference value between each signal of the above and each signal of the plurality of second signals, the plurality of first signals and the plurality of second signals are each divided into a plurality of ranges, and the plurality of first signals are divided into a plurality of ranges. A calculation unit that calculates a second deviation amount between the one signal and the plurality of second signals, and a control unit that controls the optical system based on the second deviation amount calculated by the calculation unit. Be prepared.

According to the present invention, when focusing on a perspective competing subject, the focus detection signal sequence can be appropriately divided according to the perspective of the subject according to the situation of the subject, and then the focus can be adjusted.

It is a figure which shows the structure of the image pickup apparatus which has the focal point detection apparatus in one Embodiment of this invention. It is a figure which shows the focus detection sensor and the microlens array which covers the focus detection sensor. It is a figure which shows the correspondence relationship between a focus detection pixel and a microlens. It is a flowchart of the focus detection process performed by a control device. It is a figure which shows an example which includes two subject images in a focus detection area. It is a flowchart of the defocus amount determination process performed by a control device. It is a figure which shows the change of the focus detection signal value of a pair of focus detection signal trains with respect to the focus detection pixel position in a focus detection area. It is a figure which shows the state which shifted the pair of focus detection signal trains relatively by the specific shift amount which gives the minimum value of the correlation amount of a pair of focus detection signal trains. It is a figure for demonstrating the division processing of a pair of focus detection signal trains. It is a figure which shows the change of the focus detection signal value when the correlation amount in a pair of partial signal trains takes the minimum value. It is a figure which shows the change of the focus detection signal value when the correlation amount in a pair of partial signal trains takes the minimum value. It is a flowchart of the imaging process performed by a control device. It is a figure which shows an example which includes three subject images in a focus detection area. It is a figure which shows the change of the focus detection signal value of a pair of focus detection signal trains with respect to the focus detection pixel position in a focus detection area. It is a figure which shows the state which shifted the pair of focus detection signal trains relatively by the specific shift amount which gives the minimum value of the correlation amount of a pair of focus detection signal trains. It is a figure for demonstrating the division processing of a pair of focus detection signal trains. It is a figure which shows the change of the focus detection signal value when the correlation amount in a pair of partial signal trains takes the minimum value. It is a figure which shows the change of the focus detection signal value when the correlation amount in a pair of partial signal trains takes the minimum value. It is a figure which shows the change of the focus detection signal value when the correlation amount in a pair of partial signal trains takes the minimum value. It is a figure which shows the structure of the image pickup apparatus which has another focus detection apparatus. It is a figure which shows the structure of the image pickup apparatus which has another focus detection apparatus.

The focus detection device and the image pickup device including the focus detection device according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of an image pickup apparatus 100 including a focus detection apparatus 50 according to the present embodiment. The image pickup device 100 includes a focus detection device 50, a liquid crystal display element 1, an image pickup element 2, a photographing optical system 4, a lens driving motor 5, a half mirror 7, a focus adjustment device 8, and a storage device 15. including. The focus detection device 50 includes a focus detection sensor 6, a microlens array 9, and a control device 3.

The photographing optical system 4 is an optical system for forming a subject image on an imaging surface. The photographing optical system 4 includes a plurality of lenses and an aperture, and among the plurality of lenses, the focus adjusting lens can be moved in the direction of the optical axis 10 of the photographing optical system 4 by the lens driving motor 5.

The half mirror 7 is a thin mirror such as a pellicle mirror, is located in an optical path along the optical axis 10 as shown in FIG. 1, and has an optical axis of a part of an incident light beam passing through the photographing optical system 4. It reflects in the direction of 10a, that is, toward the microlens array 9, and transmits the unreflected rest of the incident light beam. The reflected light flux reflected by the half mirror 7 passes through the microlens array 9 formed by arranging a plurality of microlenses two-dimensionally, and is incident on the focus detection sensor 6. The transmitted luminous flux transmitted through the half mirror 7 is incident on the image pickup device 2. The microlens array 9 is arranged on the image plane of the photographing optical system 4, and its position is equivalent to the position of the image pickup surface of the image sensor 2.

The focus detection sensor 6 is arranged with a plurality of focus detection pixels that generate an electrical focus detection signal according to the received light flux. Of the plurality of focus detection pixels, a pair of focus detection pixel groups composed of some focus detection pixels in the focus detection area are among the light beams incident on the focus detection sensor 6 via the microlens array 9. By receiving a pair of light beams and performing a photoelectric conversion process, a pair of electrical focus detection signal sequences corresponding to the subject image is generated. Details will be described later with reference to FIG. When the liquid crystal display element 1 displays a through image based on a plurality of image pickup signals to be described later output by the image pickup element 2 on the screen, the focus detection area may be superimposed on the through image and displayed on the screen. .. A plurality of focus detection areas may be displayed on the screen of the liquid crystal display element 1, and one of the displayed plurality of focus detection areas may be designated by the user while looking at the screen of the liquid crystal display element 1.

When generating the pair of focus detection signal trains described above, as photoelectric conversion control of the focus detection sensor 6, for example, exposure control of a plurality of focus detection pixels, read control of a plurality of focus detection signals, and / or a plurality of read outs. Amplification control of the focus detection signal and the like are performed by the control device 3. The pair of focus detection signal sequences generated by the focus detection sensor 6 is output to the control device 3.

The control device 3 detects the focus of the photographing optical system 4 by the pupil division type phase difference detection method based on the pair of focus detection signal sequences output by the focus detection sensor 6. The control device 3 detects the amount of phase difference between the pair of focus detection signal trains as the focus detection parameter obtained by the focus detection. Alternatively, the defocus amount is calculated as a focus detection parameter according to the phase difference amount. The control device 3 determines the focus adjustment parameter based on the phase difference amount or the defocus amount, and calculates the lens drive amount of the focus adjustment lens of the photographing optical system 4 based on the determined focus adjustment parameter. Then, the lens drive amount is transmitted to the focus adjustment device 8. The focus adjustment device 8 that has received the lens drive amount drives the focus adjustment lens of the photographing optical system 4 by the lens drive amount via the lens drive motor 5. Details of the focus detection process performed by the control device 3 will be described later with reference to FIGS. 4 and 6.

During the photographing process, the half mirror 7 jumps up so as to cover the focus detection sensor 6 and is retracted from the optical path. Therefore, all the incident light flux passing through the photographing optical system 4 is incident on the image sensor 2, and the image sensor 2 A subject image is formed on the light receiving surface of the. A plurality of imaging pixels are arranged in a two-dimensional manner on the image pickup element 2, and the plurality of imaging pixels receive the incident light beam and perform photoelectric conversion to perform a photoelectric conversion to form a subject image imaged by the photographing optical system 4. Generates a plurality of electrical imaging signals corresponding to. The generated plurality of image pickup signals are output by the image pickup element 2.

The control device 3 generates an image based on a plurality of image pickup signals output by the image pickup element 2, causes the liquid crystal display element 1 to display the generated image as a through image, and responds to an image pickup instruction by the user. The image is recorded in the storage device 15 at the time of the image pickup process to be executed. The details of the imaging process performed by the control device 3 will be described later with reference to FIG.

FIG. 2 is a diagram showing a focus detection sensor 6 and a microlens array 9 covering the focus detection sensor 6. FIG. 2A shows an enlarged display of the focus detection sensor 6 and the microlens array 9 in the vicinity of the optical axis 10a shown in FIG. A plurality of focus detection pixels 60 are arranged two-dimensionally in the focus detection sensor 6. In the microlens array 9, a plurality of microlenses 90 are arranged two-dimensionally (honeycomb shape) at a pitch of 100 μm or less. Although the shape of the microlens 90 is shown as a sphere, it may be hexagonal according to the honeycomb-like arrangement.

FIG. 2B is an superimposed view of the microlens array 9 and the focus detection sensor 6 on the other side thereof when viewed from directly above the microlens array 9. In the example of FIG. 2B, each microlens 90 corresponds to a plurality of focus detection pixels 60 composed of 5 pixels in the vertical direction and 5 pixels in the horizontal direction. A part of the incident luminous flux that has passed through the photographing optical system 4 shown in FIG. 1 is reflected by the half mirror 7, and the reflected luminous flux that arrives is transmitted through the microlens array 9 and incident on the focus detection sensor 6. As will be described later with reference to FIG. 3, the light beam transmitted through each microlens 90 is received by a plurality of focus detection pixels 60 consisting of a total of 25 pixels of 5 pixels in the vertical direction and 5 pixels in the horizontal direction corresponding to each microlens 90. It is converted into an electrical focus detection signal by photoelectric conversion. The plurality of focus detection pixels 60 corresponding to each microlens 90 are not limited to a total of 25 pixels of 5 pixels in the vertical direction and 5 pixels in the horizontal direction.

FIG. 3 is a diagram showing a correspondence relationship between the plurality of focus detection pixels 60 and the microlens 90. 3A and 3B are plan views of the plurality of focus detection pixels 60 and the microlens 90. In the example shown in FIGS. 3A and 3B, the plurality of focus detection pixels 60 corresponding to each microlens 90 are 5 pixels in the vertical direction and 5 pixels in the horizontal direction, for a total of 25 pixels. From the focus detection pixels 60 of those 25 pixels, the above-mentioned pair of focus detection pixel groups is defined. In the example of the focus detection pixel 60 having a total of 25 pixels of 5 pixels in the vertical direction and 5 pixels in the horizontal direction corresponding to each microlens 90 shown in FIG. 3A, two vertical focus detections located at both ends in the horizontal direction are detected. Of the five focus detection pixels included in each of the pixel sequences, the three center focus detection pixels are hatched and shown as a pair of focus detection pixel groups 610a and 610b.

In the example of the focus detection pixel 60 having a total of 25 pixels of 5 pixels in the vertical direction and 5 pixels in the horizontal direction corresponding to each microlens 90 shown in FIG. Of the five focus detection pixels included in each of the focus detection pixel array and the adjacent vertical focus detection pixel array, the central three focus detection pixels are a pair of focus detection pixel groups 620a. And one of 620b, as a focus detection pixel group 620a, is shown hatched. Of the five focus detection pixels included in each of the vertical focus detection pixel array located at the right end of the horizontal paper and the vertical focus detection pixel array adjacent to it, the three in the center. Each focus detection pixel is hatched and shown as the other focus detection pixel group 620b of the pair of focus detection pixel groups 620a and 620b. As shown in FIG. 3B, each of the pair of focus detection pixel groups 620a and 620b has a total of six focal points by arranging three focus detection pixels arranged in the vertical direction in two rows adjacent to each other in the horizontal direction. Includes detection pixels.

3 (c) and 3 (d) show the focus detection pixels 60 and the microlens 90, which have a total of 25 pixels of 5 pixels in the vertical direction and 5 pixels in the horizontal direction shown in FIGS. 3 (a) and 3 (b), respectively. It is sectional drawing when the plan view is cut by the one-point chain line S1 and S2 extending in the horizontal direction through the focus detection pixel located at the center of the focus detection pixel 60 of 25 pixels. In FIG. 3C, the pair of focus detection pixel groups 610a and 610b receive the pair of luminous fluxes 11 and 12 passing through the pair of pupil regions of the photographing optical system 4 and the microlens 90, and are electrically converted by photoelectric conversion. Generate a pair of focus detection signals. FIG. 3A exemplifies five combinations of a 25-pixel focus detection pixel 60 and a microlens 90. Therefore, the focus detection signal sequence including the five focus detection signals generated by the five focus detection pixel groups 610a and the focus detection signal sequence including the five focus detection signals generated by the five focus detection pixel groups 610b are included. Obtained, these two focus detection signal sequences form a pair of focus detection signal sequences. Similarly, in FIG. 3D, the pair of focus detection pixel groups 620a and 620b receive the pair of luminous fluxes 13 and 14 passing through the pair of pupil regions of the photographing optical system 4 and the microlens 90, and are subjected to photoelectric conversion. Generates a pair of electrical focus detection signals. FIG. 3B illustrates five combinations of a 25-pixel focus detection pixel 60 and a microlens 90. Therefore, five focus detection signal sequences generated by the five focus detection pixel groups 620a and five focus detection signal sequences generated by the five focus detection pixel groups 620b are obtained, and these two focus detection signal sequences are obtained. Form a pair of focus detection signal sequences.

The focus of the photographing optical system 4 can be adjusted based on the phase difference of the pair of focus detection signal trains thus obtained or the defocus amount calculated based on the phase difference. The distance between the pair of focus detection pixel groups 610a and 610b shown in FIG. 3C is larger than the distance between the pair of focus detection pixel groups 620a and 620b shown in FIG. 3D. Therefore, the size of the opening angle formed by the pair of luminous fluxes 11 and 12 shown in FIG. 3C is larger than the size of the opening angle formed by the pair of luminous fluxes 13 and 14 shown in FIG. 3D. Although the present invention can be applied in any case, the larger the opening angle, the easier it is to detect the difference in the change in the focus detection signal value due to the perspective competition described later. It is preferable to apply the present invention when a configuration having a large opening angle as shown in FIG. 3C can be adopted.

FIG. 4 is a flowchart of the focus detection process performed by the control device 3. The control device 3 is, for example, a computer composed of a CPU and a memory. When the CPU executes a computer program stored in the memory, the processing of each step constituting the focus detection processing shown in FIG. 4 is performed.

The processing of each step constituting the focus detection processing shown in FIG. 4 will be described with reference to the example of the photographing screen 250 shown in FIG. In FIG. 5, the photographing screen 250 includes two subject images imaged by the photographing optical system 4, that is, a background subject image 210 including trees and a person subject image 220. A focus detection area 200 is also displayed on the shooting screen 250, and in the focus detection area 200, a background subject image 210 including a tree located far from the image pickup device 100 and a person located near the image pickup device 100 are displayed. The subject image 220 and the like are included. Normally, a plurality of focus detection areas 200 are displayed on the shooting screen 250, but on the shooting screen 250 of FIG. 5, one focus detection area 200 designated by the user in step S101 of FIG. 4 to be described later. Only exemplify.

In step S101, the control device 3 determines whether or not the main focus detection process is started by the user via an operation member (not shown) and the focus detection area 200 is designated. In the case of a negative determination, the process of step S101 is repeated until an affirmative determination is made. In the case of an affirmative determination, the control device 3 advances the present process targeting the designated focus detection area 200 to step S102. The above-mentioned operating member is, for example, an automatic focus detection activation switch, and this process is started when the automatic focus detection activation switch is set to ON. Alternatively, the operating member is a shutter release button, and this process is started when the shutter release button is set to the half-pressed state.

In step S102, the control device 3 performs photoelectric conversion control of the focus detection sensor 6. The photoelectric conversion control of the focus detection sensor 6 includes, for example, exposure control of a plurality of focus detection pixels 60 arranged in the focus detection sensor 6, read control of a plurality of focus detection signals, and / or a plurality of read focus detection signals. Amplification control and the like are performed.

In step S103, the control device 3 acquires a pair of focus detection signal sequences based on the plurality of focus detection signals read in step S102.

In step S104, the control device 3 performs a defocus amount determination process for determining the defocus amount for focus adjustment. The details of the defocus amount determination process will be described later with reference to FIG.

In step S105, the control device 3 determines whether or not the photographing optical system 4 is in the in-focus position based on whether or not the defocus amount for focus adjustment determined in step S104 is substantially 0. In the case of an affirmative judgment, this process ends. In the case of a negative determination, this process proceeds to step S106. It should be noted that the control device 3 may determine the reliability of the defocus amount for focus adjustment determined in step S104, and if it is determined that the reliability is low and the focus cannot be detected, a scanning operation may be performed. .. If the subject image disappears from the focus detection area 200 after the focus adjustment lens drive has already started, the focus adjustment lens is driven based on the most recently detected focus adjustment defocus amount, and then this process is performed. You may end it.

In step S106, the control device 3 calculates the lens drive amount of the photographing optical system 4 based on the focus adjustment defocus amount determined in step S104.

In step S107, the control device 3 transmits the lens drive amount calculated in step S106 to the focus adjustment device 8, and causes the focus adjustment device 8 to drive the lens of the photographing optical system 4 via the lens drive motor 5. As a result, the focus adjusting device 8 is controlled. When the process of step S107 is completed, this process returns to step S101.

FIG. 6 is a flowchart showing details of the defocus amount determination process performed by the control device 3 in step S104 of FIG. Let it be a pair of focus detection signal sequences {a [i]} and {b [j]} acquired in step S103 of FIG. The initial value of the relative phase shift amount k of the pair of focus detection signal sequences {a [i]} and {b [j]} is 0. The closer the magnitude of the phase shift amount k is to the phase difference amount of the pair of focus detection signal sequences {a [i]} and {b [j]}, the closer the pair of focus detection signal sequences {a [i] } And {b [j]} have a high correlation (k = i−j). When the correlation between the pair of focus detection signal sequences {a [i]} and {b [j]} is the highest, the pair of focus detection signal sequences {a [i]} and {b represented by the following equation (1) The correlation value C (k) of [j]} indicates the minimum value. The integration on the right side of the equation (1) is performed for the number of signals of the pair of focus detection signal sequences {a [i]} and {b [j]}.
C (k) = Σ | a [i] -b [j] | (1)

In step S201, the control device 3 shifts the phases of the pair of focus detection signal sequences {a [i]} and {b [j]} acquired in step S103 of FIG. 4 by a predetermined shift amount. The minimum value C (k) _min of the correlation amount C (k) is specified by sequentially calculating the correlation amount C (k). The control device 3 acquires a specific shift amount X0 of the pair of focus detection signal sequences {a [i]} and {b [j]} that give the minimum value, and focuses detection based on the specific shift amount X0. The defocus amount D0 as a quantity parameter is calculated.

In step S202, the control device 3 determines whether or not the minimum value C (k) _min of the correlation amount C (k) specified in step S201 is smaller than the predetermined threshold value C (k) _th. In the case of an affirmative determination, the control device 3 advances this process to step S208. As shown in FIG. 5, when a distant subject image and a near subject image are included in the focus detection area 200, the minimum value C (k) _min of the correlation amount C (k) is given. Even if the relative phases of the pair of focus detection signal sequences {a [i]} and {b [j]} are shifted by a specific shift amount (X0), the pair of focus detection signal sequences {a [i] } And {b [j]} do not match over the entire focus detection area, resulting in a partially non-matching interval (described later with reference to FIG. 8). Therefore, the minimum value C (k) _min of the correlation amount C (k) is separated from 0. On the contrary, when there is no mixture of a distant subject image and a near subject image in the focus detection area 200, or when the distance difference between the distant subject image and the near subject image is small, there is a correlation. The minimum value C (k) _min of the quantity C (k) approaches 0. In such a case, it is not necessary to apply the present invention. Therefore, if a negative determination is made in step S202, the control device 3 advances the present process to step S203.

In step S203, the control device 3 determines the brightness of the subject image 210 including the background subject image 210 including trees and the subject image 220 including the subject image 220 of a person within the focus detection area 200 designated in step S101 of FIG. Determine if it is darker than the brightness. In the case of affirmative determination, that is, when the brightness of the subject image is darker than the predetermined brightness, there is a possibility that the amplification control is performed with a large amplification degree in step S102 of FIG. If amplification control is performed with a large amplification degree, the noise superimposed on the focus detection signal will also be amplified. In such a case, since an error is likely to occur in the calculation of the difference between the focus detection signals described later in the description of step S204, the present invention is not applied. Therefore, the control device 3 performs this process. Proceed to step S208. If a negative determination is made in step S203, the control device 3 advances this process to step S204.

As the brightness determination index in step S203 of FIG. 6, for example, the magnitude of the amplification degree of the amplification control performed in step S102 of FIG. 4 is used. When the amplification degree is less than a predetermined value, the control device 3 determines that the brightness of the entire subject image is not darker than the predetermined brightness, that is, a negative determination is made in step S203.

In step S204, the control device 3 has a pair of focus detection signal sequences {a [i]} and {b [j]}, that is, correlations, which are relatively shifted by the specific shift amount X0 acquired in step S201. The absolute value of the difference between the corresponding focus detection signals in the pair of focus detection signal sequences {a [i]} and {b [j]} shifted to the highest state | a [i] -b [j] | Multiple differences are obtained by sequential calculation.

In step S205, the control device 3 distantly shifts the pair of focus detection signal sequences {a [i]} and {b [j]} acquired in step S201 by the specific shift amount X0. Divide into two pairs of partial signal sequences, one is a pair of partial signal sequences corresponding to the subject image (the subject image 210 in the background including trees) and the other is a pair of partial signal sequences corresponding to the nearby subject image (the subject image 220 of a person). .. For example, in the control device 3, each of the plurality of differences obtained by sequentially calculating the absolute value | a [i] −b [j] | of the difference in step S204 is equal to or greater than the average value of the plurality of differences. Based on whether or not, the division process in step S205 is performed. Details will be described later with reference to FIG.

In step S206, the control device 3 calculates the amount of phase difference between each pair of partial signal trains of the two pairs of partial signal trains obtained in step S205. The two phase difference quantities X1 and X2 corresponding to each of the two pairs of partial signal sequences calculated in this way are a kind of focus detection parameters. Therefore, it is possible to perform the processing after step S207 based on these two phase difference amounts X1 and X2, but further, here, the control device 3 further determines two devices based on the two phase difference amounts X1 and X2. The focus amounts D1 and D2 are calculated. The two defocus quantities D1 and D2 corresponding to each of the two pairs of subsignal sequences are also a type of focus detection parameter.

In step S207, the control device 3 determines the closest defocus amount of the two defocus amounts D1 and D2 calculated in step S206 as the focus adjustment defocus amount. The defocus amount on the closest side is specified based on the fact that the focusing position of the photographing optical system 4 with respect to the subject closest to the image pickup apparatus 100 is located at the position farthest from the photographing optical system 4. Of the two defocus amounts D1 and D2 calculated in step S206, the defocus amount corresponding to the nearby subject image (human subject image 220) is the nearest defocus amount. When the process of step S207 is completed, this process ends, and the control device 3 advances the focus detection process of FIG. 4 to S105.

In step S208, which is performed when an affirmative determination is made in step S202 or S203, the control device 3 identifies the pair of focus detection signal sequences {a [i]} and {b [j]} acquired in step S201. The defocus amount D0 calculated based on the shift amount X0 of is determined as the defocus amount for focus adjustment. When the process of step S208 is completed, this process ends, and the control device 3 advances the focus detection process of FIG. 4 to S105.

FIG. 7 corresponds to the example of the photographing screen 250 shown in FIG. 5, and shows a pair of focus detection signal sequences {a [i] with respect to the focus detection pixel positions in the focus detection area 200 having a length of about 50 pixels in the horizontal direction. ]} And {b [j]} are diagrams showing changes in the focus detection signal values. The pair of focus detection signal sequences {a [i]} and {b [j]} shown in FIG. 7 are the pair of focus detection signal sequences 655a and 655b, which are the pair of focus detection signals acquired in step S103 of FIG. Corresponds to the column. In FIG. 7, the sections 310 of the focus detection pixel positions 1 to 13 in the horizontal direction in the focus detection area 200 correspond to the subject image 220 of a person at a position close to the image pickup apparatus 100 shown in FIG. The phase of one of the pair of focus detection signal sequences 655a and 655b of the focus detection signal sequence 655a is ahead of the phase of the other focus detection signal sequence 655b. In FIG. 7, the section 320 of the horizontal focus detection pixel positions 14 to 46 in the focus detection area 200 corresponds to the subject image 210 in the background including the tree at a position far from the image pickup apparatus 100 shown in FIG. In the interval, the phase of one of the focus detection signal trains 655a and 655b of the pair of focus detection signal trains 655a is behind the phase of the other focus detection signal train 655b. The correlation amount C (k) is the minimum value C (k) due to the relative shift of the phase of the specific shift amount (X0) performed in step S201 of FIG. 6 with respect to the pair of focus detection signal sequences 655a and 655b. The pair of focus detection signal sequences {a [i]} and {b [j]} when _min is indicated are exemplified in FIG. 8 as a pair of focus detection signal sequences 660a and 660b.

FIG. 8 shows relative to a specific shift amount X0 that gives the minimum value C (k) _min of the correlation amount C (k) of the pair of focus detection signal sequences {a [i]} and {b [j]}. It is a figure which shows the state which shifted the pair of focus detection signal sequences {a [i]} and {b [j]} of 7. Correlation of the pair of focus detection signal sequences 655a and 655b in the section 320 corresponding to the background subject image 210 including trees than in the section 310 corresponding to the subject image 220 of the person shown in FIG. 7 because the contrast is higher. But suppose it is higher. In that case, the specific shift amount X0 acquired in step S201 of FIG. 6 may be greatly affected by the subject image 210 in the background including trees. Therefore, only the specific shift amount X0 is relative to the pair in FIG. 7. When the focus detection signal sequences {a [i]} and {b [j]} of the above are shifted, as shown in FIG. 8, the horizontal direction in the focus detection area 200 corresponding to the subject image 210 of the background including trees. In the section 320 of the focus detection pixel positions 14 to 46, the pair of focus detection signal sequences 660a and 660b may be close to the coincident state. As shown in FIG. 8, in the section 310 of the horizontal focus detection pixel positions 1 to 13 in the focus detection area 200 corresponding to the subject image 220 of a person, between the pair of focus detection signal sequences 660a and 660b. There is a phase difference. The entire horizontal section 300 of the focus detection area 200 is divided into the section 310 corresponding to the subject image 220 of the person described above and the subject image 210 of the background including trees between the focus detection pixel positions 13 and 14. A method of specifying the boundary 350 that is divided into the corresponding section 320 will be described with reference to FIG.

FIG. 9 is a diagram for explaining the division processing of the pair of focus detection signal sequences {a [i]} and {b [j]} shown in FIG. 7, and corresponds to the processing in step S204 of FIG. .. FIG. 9 shows a pair of focus detection signals in the state of FIG. 8 in which the pair of focus detection signal sequences {a [i]} and {b [j]} of FIG. 7 are relatively shifted by a specific shift amount X0. By sequentially calculating the absolute value | a [i] -b [j] | of the difference between the corresponding focus detection signals in the columns 660a and 660b, for each horizontal focus detection pixel position in the focus detection area 200. It represents the variation of the plurality of differences 671 obtained.

In the entire section 300 in the horizontal direction of the focus detection area 200, in the section 320 corresponding to the subject image 210 of the background including the above-mentioned tree, the change in the position of the focus detection pixel in the horizontal direction in the focus detection area 200 The variation of the absolute value | a [i] -b [j] | of the difference with respect to is generally small. In the section 310 corresponding to the subject image 220 of the person described above, the absolute value of the difference | a [i] -b [j] each time the horizontal focus detection pixel position in the focus detection area 200 increases by one pixel. | Is increasing or decreasing sharply. When the average value of a plurality of differences 671 over the entire section 300 in the horizontal direction of the focus detection area 200 is obtained, the absolute value of the difference indicating a value equal to or higher than the average value is obtained in the section 320 corresponding to the subject image 210 in the background including trees. The value | a [i] -b [j] | does not exist, but in the section 310 corresponding to the subject image 220 of the person, the absolute value of the difference indicating a value equal to or more than the average value | a [i] -b [j] There are many |. Therefore, in FIG. 9, with respect to the change in the focus detection pixel position in the horizontal direction in the focus detection area 200, each of the plurality of differences 671 changes below the average value of the plurality of differences 671, that is, the focal point. The section between the detection pixel positions 14 to 46 can be specified as the section 320, and the boundary 350 can be specified such that the boundary 350 is located between the focus detection pixel positions 13 and 14. Of the entire section 300, the sections of the focus detection pixel positions 1 to 13, which are sections on the opposite side of the boundary 350 with the boundary 350 in between, can be specified as the section 310. Based on this result, in step S205 of FIG. 6, the pair of focus detection signal sequences 655a and 655b shown in FIG. 7 showing the current focus state are the sections of the focus detection pixel positions 1 to 13 corresponding to the subject image 220 of the person. It can be divided into a pair of partial signal sequences of 310 and a pair of partial signal sequences of sections 320 of the focus detection pixel positions 14 to 46 corresponding to the subject image 210 of the background including trees.

FIG. 10 shows the focus detection signals of the pair of partial signal sequences 661a and 661b when the amount of correlation in the pair of partial signal sequences in the section of the focus detection pixel positions 1 to 13 corresponding to the subject image 220 of the person is the minimum value. It is a figure which shows the change of a value. As described above, in step S205 of FIG. 6, by dividing the pair of focus detection signal sequences 655a and 655b shown in FIG. 7, a pair of sections of focus detection pixel positions 1 to 13 corresponding to the subject image 220 of a person. A subsignal sequence of is obtained. The phase difference amount X1 of the pair of partial signal trains can be obtained by performing the correlation calculation while shifting the phase of the pair of partial signal trains in the section of the focus detection pixel positions 1 to 13 corresponding to the subject image 220 of the person. FIG. 10 shows a state in which a pair of partial signal sequences in the sections of the focus detection pixel positions 1 to 13 corresponding to the subject image 220 of a person are relatively shifted by the phase difference amount X1. In step S206 of FIG. 6, the defocus amount D1 is calculated based on the phase difference amount X1.

FIG. 11 shows the pair of partial signal sequences 662a and 662b when the amount of correlation in the pair of partial signal sequences in the section of the focal detection pixel positions 14 to 46 corresponding to the background subject image 210 including trees has the minimum value. It is a figure which shows the change of the focus detection signal value. As described above, in step S205 of FIG. 6, by dividing the pair of focus detection signal sequences 655a and 655b shown in FIG. 7, the focus detection pixel positions 14 to 46 corresponding to the subject image 210 of the background including trees A pair of sub-signal sequences of intervals is obtained. By performing the correlation calculation while shifting the phase of the pair of partial signal trains in the section of the focus detection pixel positions 14 to 46 corresponding to the subject image 210 of the background including trees, the phase difference amount X2 of the pair of partial signal trains can be obtained. can get. FIG. 11 shows a state in which a pair of partial signal sequences in the section of the focus detection pixel positions 14 to 46 corresponding to the subject image 210 in the background including trees are relatively shifted by the phase difference amount X2. In step S206 of FIG. 6, the defocus amount D2 is calculated based on the phase difference amount X2.

FIG. 12 is a flowchart of an imaging process performed by the control device 3. As described above, the control device 3 is, for example, a computer composed of a CPU and a memory. When the CPU executes a computer program stored in the memory, the processing of each step constituting the imaging process shown in FIG. 12 is performed.

In step S501, the control device 3 determines whether or not an imaging instruction has been given by the user via the operating member. In the case of a negative determination, the process of step S501 is repeated until an affirmative determination is made. In the case of an affirmative determination, the control device 3 advances this process to step S502. The operating member is, for example, a shutter release button, and when the shutter release button is set to the fully pressed state, an affirmative determination is made in step S501.

In step S502, the control device 3 controls the photoelectric conversion of the image sensor 2. As the photoelectric conversion control of the image pickup device 2, for example, exposure control of a plurality of image pickup pixels arranged in the image pickup element 2, read control of a plurality of image pickup signals, and / or amplification control of a plurality of read image pickup signals are performed. It is said.

In step S503, the control device 3 acquires a plurality of imaging signals read out in step S502 and whose amplification control has been performed.

In step S504, the control device 3 generates an image based on the plurality of imaging signals acquired in step S503.

In step S505, the control device 3 records the image generated in step S504 in the storage device 15. When the process of step S505 is completed, this process ends.

The focus detection device 50 in the present embodiment includes the focus detection sensor 6 and the control device 3 as described above. The focus detection sensor 6 receives a pair of light fluxes that have passed through the pair of pupil regions of the photographing optical system 4, and outputs a pair of focus detection signal sequences 655a and 655b, respectively, which are composed of a plurality of focus detection signals. The control device 3 obtains a plurality of differences 671 by sequentially calculating the absolute value | a [i] −b [j] | of the difference between the corresponding focus detection signals in the pair of focus detection signal sequences 655a and 655b. .. Based on the obtained plurality of differences 671, the control device 3 performs a pair of focus detection signal sequences 655a and 655b, a pair of partial signal sequences corresponding to a subject image 220 of a person located close to the image pickup apparatus 100, and a pair of partial signal sequences. It is divided into at least two pairs of partial signal sequences of a pair of partial signal sequences corresponding to a subject image 210 in the background including a tree located far from the image pickup apparatus 100. The control device 3 has a defocus amount D1 corresponding to the phase difference amount X1 of the pair of partial signal trains corresponding to the subject image 220 of the person, and the position of the pair of partial signal trains corresponding to the subject image 210 of the background including trees. The defocus amount D2 corresponding to the phase difference amount X2 is calculated. The control device 3 determines any one of the defocus amounts D1 and D2 as the focus adjustment defocus amount used for the focus adjustment. Therefore, it is possible to focus on either the background subject image 210 including trees located far from the image pickup device 100 or the subject image 220 of a person located near from the image pickup device 100.

The control device 3 calculates the defocus amounts D1 and D2, respectively, and determines the defocus amount on the nearest side of the defocus amounts D1 and D2 as the focus adjustment defocus amount. Therefore, it is possible to focus on the subject image 220 of a person located close to the image pickup apparatus 100.

--- Modification example ---
(1) In the above-described embodiment, as shown in FIG. 5, the present invention is applied to an example in which the focus detection area 200 includes two subject images, but three or more subject images are included in the focus detection area 200. The present invention can be applied even when the above is included. This will be described with reference to FIG.

FIG. 13 is a diagram showing an example in which the focus detection area 200 in the photographing screen 250 includes three subject images 210, 220, and 230. The shooting screen 250 and the focus detection area 200 include a background subject image 210 including trees, a subject image 220 of a person, and a subject image 230 of another person. Normally, a plurality of focus detection areas 200 are displayed on the shooting screen 250, but in the shooting screen 250 of FIG. 13, only one focus detection area 200 designated by the user is illustrated. Based on the example shown in FIG. 13, the focus detection process by the control device 18 will be described with reference to FIGS. 14 to 19.

FIG. 14 corresponds to the example of the photographing screen 250 shown in FIG. 13, and shows a pair of focus detection signal sequences {a [i] with respect to the focus detection pixel positions in the focus detection area 200 having a length of about 50 pixels in the horizontal direction. ]} And {b [j]} are diagrams showing changes in the focus detection signal values. The pair of focus detection signal sequences {a [i]} and {b [j]} shown in FIG. 14 is a pair of focus detection signal sequences 655a and 655b obtained by a process according to step S103 of FIG. Corresponds to the focus detection signal sequence. In FIG. 14, the section 310 of the focus detection pixel positions 1 to 12 in the horizontal direction in the focus detection area 200 corresponds to the subject image 220 of a person at a position close to the image pickup apparatus 100 shown in FIG. The phase of one of the pair of focus detection signal sequences 655a and 655b of the focus detection signal sequence 655a is behind the phase of the other focus detection signal sequence 655b. In FIG. 14, the section 320 of the horizontal focus detection pixel positions 13 to 28 in the focus detection area 200 corresponds to the subject image 210 in the background including the tree at a position far from the image pickup apparatus 100 shown in FIG. In the section, the phase of one of the pair of focus detection signal sequences 655a and 655b, the focus detection signal sequence 655a, is ahead of the phase of the other focus detection signal sequence 655b. In FIG. 14, the section 330 of the horizontal focus detection pixel positions 29 to 46 in the focus detection area 200 corresponds to the subject image 230 of another person at the position closest to the image pickup apparatus 100 shown in FIG. In this section, the phase of one of the pair of focus detection signal sequences 655a and 655b, the focus detection signal sequence 655a, lags significantly behind the phase of the other focus detection signal sequence 655b. The correlation amount C (k) is the minimum value due to the relative shift of the phase of a specific shift amount (X0) performed in the process according to step S201 of FIG. 6 with respect to the pair of focus detection signal sequences 655a and 655b. The pair of focus detection signal sequences {a [i]} and {b [j]} when C (k) _min is shown are exemplified in FIG. 15 of the pair of focus detection signal sequences 660a and 660b.

FIG. 15 shows relative to a specific shift amount X0 that gives the minimum value C (k) _min of the correlation amount C (k) of the pair of focus detection signal sequences {a [i]} and {b [j]}. It is a figure which shows the state which shifted the pair of focus detection signal sequences {a [i]} and {b [j]} of 14. In FIG. 13, in the horizontal direction of the focus detection area 200, the subject image 220 of a person is located on the left side of the focus detection area 200 toward the paper surface, the subject image 210 of the background including trees is located in the center, and the subject image 210 of the background including trees is located on the right side. The subject image 230 of one person is located. The contrast is higher in the section 310 corresponding to the subject image 220 of the person shown in FIG. 14 and the section 320 corresponding to the subject image 210 in the background including trees than in the section 330 corresponding to the subject image 230 of another person. Therefore, it is assumed that the correlation between the pair of focus detection signal sequences 655a and 655b is higher. In that case, the specific shift amount X0 acquired in the process according to step S201 of FIG. 6 may be greatly affected by the subject image 210 in the background including trees. In that case, when the pair of focus detection signal sequences {a [i]} and {b [j]} of FIG. 14 are relatively shifted by a specific shift amount X0, as shown in FIG. 15, the background including trees is included. In the section 320 of the horizontal focus detection pixel positions 13 to 28 in the focus detection area 200 corresponding to the subject image 210, the pair of focus detection signal sequences 660a and 660b may be close to the same state.

As shown in FIG. 15, in the section 310 of the horizontal focus detection pixel positions 1 to 12 in the focus detection area 200 corresponding to the subject image 220 of a person, between the pair of focus detection signal sequences 660a and 660b. There is a phase difference. As shown in FIG. 15, in the section 330 of the horizontal focus detection pixel positions 29 to 46 in the focus detection area 200 corresponding to the subject image 230 of another person, the pair of focus detection signal sequences 660a and 660b There is a phase difference between them. The entire horizontal section 300 of the focus detection area 200 is divided between the focus detection pixel positions 12 and 13 into a section 310 corresponding to the subject image 220 of the person described above and a background subject image 210 including trees. A method for specifying a boundary 350 that divides into a corresponding section 320, a section 320 that corresponds to a background subject image 210 including trees, and a boundary 360 that divides into a section 330 that corresponds to a subject image 230 of another person. Will be described with reference to FIG.

FIG. 16 is a diagram for explaining a division process of the pair of focus detection signal sequences {a [i]} and {b [j]} shown in FIG. 14, and is a process according to step S204 of FIG. handle. FIG. 16 shows a pair of focus detection signals in the state of FIG. 15 in which the pair of focus detection signal sequences {a [i]} and {b [j]} of FIG. 14 are relatively shifted by a specific shift amount X0. By sequentially calculating the absolute value | a [i] -b [j] | of the difference between the corresponding focus detection signals in the columns 660a and 660b, for each horizontal focus detection pixel position in the focus detection area 200. It represents the variation of the plurality of differences 671 obtained. In the entire section 300 in the horizontal direction of the focus detection area 200, in the section 320 corresponding to the subject image 210 of the background including the above-mentioned tree, the change in the position of the focus detection pixel in the horizontal direction in the focus detection area 200 The variation of the absolute value | a [i] -b [j] | of the difference with respect to is generally small.

In the section 310 corresponding to the subject image 220 of the person and the section 330 corresponding to the subject image 230 of another person described above, each time the horizontal focus detection pixel position in the focus detection area 200 increases by one pixel. The absolute value of the difference | a [i] -b [j] | is increasing or decreasing sharply. When the average value of a plurality of differences 671 over the entire section 300 in the horizontal direction of the focus detection area 200 is obtained, the absolute value of the difference indicating a value equal to or higher than the average value is obtained in the section 320 corresponding to the subject image 210 in the background including trees. The value | a [i] -b [j] | does not exist, but the section 310 corresponding to the subject image 220 of a person and the section 330 corresponding to the subject image 230 of another person show a value equal to or higher than the average value. The absolute value of the difference | a [i] -b [j] | is common. Therefore, in FIG. 16, with respect to the change in the focus detection pixel position in the horizontal direction within the focus detection area 200, each of the plurality of differences 671 changes below the average value of the plurality of differences 671, that is, the focal point. The section of the detection pixel positions 13 to 28 can be specified as the section 320, the boundary 350 is located between the focus detection pixel positions 12 and 13, and the boundary 360 is located between the focus detection pixel positions 28 and 29. Boundaries 350 and 360 can be identified as such. Of the entire section 300, the sections of the focus detection pixel positions 1 to 12, which are the sections on the opposite side of the section 320 with the boundary 350 in between, are specified as the sections 310, and the sections on the opposite side of the section 320 with the boundary 360 in between. The section of the focus detection pixel positions 29 to 46, which is a section, can be specified as the section 330. Based on this result, in the three-division process that can be performed according to step S205 of FIG. 6, the pair of focus detection signal sequences 655a and 655b shown in FIG. A pair of partial signal sequences in the section of the focus detection pixel positions 1 to 12 corresponding to, a pair of partial signal sequences in the section of the focus detection pixel positions 13 to 28 corresponding to the subject image 210 of the background including trees, and another. It can be divided into a pair of partial signal sequences in the section of the focus detection pixel positions 29 to 46 corresponding to the subject image 230 of the person.

FIG. 17 shows the focus detection signals of the pair of partial signal sequences 661a and 661b when the amount of correlation in the pair of partial signal sequences in the section of the focus detection pixel positions 1 to 12 corresponding to the subject image 220 of the person is the minimum value. It is a figure which shows the change of a value. As described above, in the three-division process that can be performed according to step S205 of FIG. 6, the pair of focus detection signal sequences 655a and 655b shown in FIG. 14 are divided to correspond to the subject image 220 of a person. A pair of partial signal sequences in the section of the focus detection pixel positions 1 to 12 to be performed is obtained. The phase difference amount X1 of the pair of partial signal trains can be obtained by performing the correlation calculation while shifting the phase of the pair of partial signal trains in the section of the focus detection pixel positions 1 to 12 corresponding to the subject image 220 of the person. FIG. 17 shows a state in which a pair of partial signal sequences in the sections of the focus detection pixel positions 1 to 12 corresponding to the subject image 220 of a person are relatively shifted by the phase difference amount X1. In the process according to step S206 of FIG. 6, the defocus amount D1 is calculated based on the phase difference amount X1.

FIG. 18 shows the pair of partial signal sequences 662a and 662b when the amount of correlation in the pair of partial signal sequences in the section of the focus detection pixel positions 13 to 28 corresponding to the background subject image 210 including trees has the minimum value. It is a figure which shows the change of the focus detection signal value. As described above, in the three-division process that can be performed according to step S205 of FIG. 6, by dividing the pair of focus detection signal sequences 655a and 655b shown in FIG. 14, the subject image of the background including trees A pair of partial signal sequences in the section of the focus detection pixel positions 13 to 28 corresponding to 210 is obtained. By performing the correlation calculation while shifting the phase of the pair of partial signal trains in the section of the focus detection pixel positions 13 to 28 corresponding to the subject image 210 of the background including trees, the phase difference amount X2 of the pair of partial signal trains can be obtained. can get. FIG. 18 shows a state in which a pair of partial signal sequences in the section of the focus detection pixel positions 13 to 28 corresponding to the subject image 210 in the background including trees are relatively shifted by the phase difference amount X2. In the process according to step S206 of FIG. 6, the defocus amount D2 is calculated based on the phase difference amount X2.

FIG. 19 shows a pair of sub-signal sequences 663a and 663b when the amount of correlation in the pair of sub-signal sequences in the section of the focus detection pixel positions 29 to 46 corresponding to the subject image 230 of another person is the minimum value. It is a figure which shows the change of the focus detection signal value. As described above, in the three-division process that can be performed according to step S205 of FIG. 6, the subject image of another person is obtained by dividing the pair of focus detection signal sequences 655a and 655b shown in FIG. A pair of partial signal sequences in the interval of the focus detection pixel positions 29 to 46 corresponding to 230 is obtained. By performing the correlation calculation while shifting the phase of the pair of partial signal trains in the section of the focus detection pixel positions 29 to 46 corresponding to the subject image 230 of the other person, the phase difference amount X3 of the pair of partial signal trains Is obtained. FIG. 19 shows a state in which a pair of partial signal sequences in the section of the focus detection pixel positions 29 to 46 corresponding to the subject image 230 of the other person are relatively shifted by the phase difference amount X3. In the process according to step S206 of FIG. 6, the defocus amount D3 is calculated based on the phase difference amount X3.

(2) In step S205 of FIG. 6 of the above-described embodiment, the control device 3 sequentially calculates the absolute value | a [i] −b [j] | of the difference in step S204, so that FIG. 9 shows. The division process in step S205 is performed based on whether or not each of the plurality of differences 671 obtained as shown is equal to or greater than the average value of the plurality of differences 671. However, other methods may be used. For example, the control device 3 calculates a derivative value of a plurality of differences 671. The differential value is the absolute value of the difference between two horizontal focus detection pixel positions within the focus detection area 200 that are adjacent to each other | a [i] -b [j] | It is obtained by performing over the entire range of positions 1-46.

As described above, referring to FIG. 9, in the entire section 300 in the horizontal direction of the focus detection area 200, in the section 320 corresponding to the background subject image 210 including the trees described above, the focus detection area 200 is included. The variation of the absolute value | a [i] −b [j] | of the difference with respect to the change in the focus detection pixel position in the horizontal direction in is generally small. Therefore, the magnitude of the differential value in this interval 320 is less than a predetermined value close to 0. In the section 310 corresponding to the subject image 220 of the person described above, the absolute value of the difference | a [i] -b [j] each time the horizontal focus detection pixel position in the focus detection area 200 increases by one pixel. | Is increasing or decreasing sharply. Therefore, the magnitude of the differential value in this section 310 is equal to or larger than the above-mentioned predetermined value. That is, in step S205 of FIG. 6, the control device 3 has an absolute value | a [i] −b [j] | of the difference between the plurality of differences 671 obtained in step S204, which are adjacent to each other. A pair of focus detection signal sequences 655a and 655b, a pair of partial signal sequences corresponding to a subject image 220 of a person located close to the image pickup apparatus 100, and a pair of partial signal sequences based on whether or not the magnitude of is less than a predetermined value. It may be divided into a pair of partial signal sequences corresponding to the subject image 210 in the background including trees located far from the image pickup apparatus 100.

(3) In step S203 of FIG. 6 of the above-described embodiment, in the control device 3, the brightness of the entire subject image including the background subject image 210 including the trees and the subject image 220 of the person is higher than the predetermined brightness. Determine if it is dark. As described above, when the brightness of the entire subject image is darker than the predetermined brightness, the noise superimposed on the focus detection signal is also amplified. Therefore, in step S204, a plurality of objects are used without performing the process of step S203. When the difference is obtained, the absolute value of the difference indicating a value equal to or higher than the average value | a [i] -b even in the section of the focus detection pixel positions 14 to 46 corresponding to the subject image 210 in the background including the trees in FIG. [J] | will be included. Therefore, the control device 3 does not perform the process of step S203, and in step S204, the absolute value of the difference indicating a value equal to or more than the average value over the entire horizontal section 300 of the focus detection area 200 | a [i]-. When it is determined that b [j] | exists, this process may proceed to step S208.

(4) In the above-described embodiment, in steps S206 and S207 of FIG. 6, the control device 3 is calculated based on the two phase difference amounts X1 and X2 corresponding to each of the two pairs of partial signal sequences. Of the two defocus amounts D1 and D2, the nearest defocus amount is determined as the focus adjustment defocus amount. However, the control device 3 focuses on one defocus amount calculated based on the nearest phase difference amount of the two phase difference amounts X1 and X2 corresponding to each of the two pairs of partial signal trains. It may be determined as the defocus amount for use.

(5) In the above-described embodiment, in step S105 of FIG. 4, the control device 3 is a photographing optical system based on whether or not the defocus amount for focus adjustment determined in step S104 is substantially 0. It is determined whether or not 4 is in the in-focus position. However, step S106 is performed first, and whether or not the photographing optical system 4 is in the in-focus position is determined based on whether or not the lens drive amount of the photographing optical system 4 calculated in step S106 is substantially 0. It may be determined.

(6) In the above-described embodiment, in steps S106 and S107 of FIG. 4, the control device 3 performs focus adjustment control by driving the lens of the photographing optical system 4 based on the focus adjustment defocus amount. However, the control device 3 may perform focus adjustment control by driving the image sensor 2 based on the focus adjustment defocus amount.

(7) In the present invention, not only the focus detection device 50 having the focus detection sensor 6 covered with the microlens array 9 shown in FIG. 1 but also the half mirror 7 is transmitted and then reflected by the sub mirror 70 for reimaging. It is also applied to the focus detection device 50 having the focus detection sensor 16 that receives the light beam passing through the optical system 17 and the focus detection device 50 having the image pickup element 2 including the focus detection sensor covered with the microlens array 19. be able to. FIG. 20 shows a focus detection device 50 having a focus detection sensor 16 in which a plurality of focus detection pixels that receive light rays that have passed through the half mirror 7 and then reflected by the sub mirror 70 and passed through the reimaging optical system 17 are arranged. It is a figure which shows the structure of the image pickup apparatus 100 which has. FIG. 21 is a diagram showing a configuration of an image pickup device 100 having a focus detection device 50 having an image pickup device 2 including a focus detection sensor covered with a microlens array 19. That is, in the image pickup device 2 covered with the microlens array 19, a plurality of focus detection pixels that generate a plurality of focus detection signals and a plurality of image pickup pixels that generate a plurality of image pickup signals are arranged in a mixed manner. ing. In FIGS. 20 and 21, the parts with the same reference numerals as those in FIG. 1 are the same as those of the image pickup apparatus 100 shown in FIG. 1, and thus the description thereof will be omitted.

In the image pickup apparatus 100 shown in FIG. 21, the magnitude of the ISO sensitivity during the image pickup process by the image pickup device 2 may be used as a determination index of the brightness in step S203 of FIG. When the ISO sensitivity is less than a predetermined value, the control device 3 determines that the brightness of the entire subject image is not darker than the predetermined brightness, that is, a negative determination is made in step S203.

The above-described embodiments and modifications may be combined. The present invention is not limited to the above-described embodiments and modifications as long as the features of the present invention are not impaired, and other embodiments considered within the scope of the technical idea of the present invention are also within the scope of the present invention. included.

1 Liquid crystal display element, 2 Image sensor, 3 Control device, 4 Imaging optical system,
5 Lens drive motor, 6 Focus detection sensor, 7 Half mirror,
8 focus adjuster, 9 microlens array, 10 optical axis,
15 storage device, 16 focus detection sensor, 17 re-imaging optical system,
19 microlens array, 50 focus detector, 70 submirror

Claims (7)

A lens in which light that has passed through an optical system that forms an image of a subject is incident, a first light receiving unit that receives light transmitted through the lens and outputs a first signal, and a second light receiving unit that receives light transmitted through the lens and outputs a first signal. A detection unit having a plurality of sensors including a second light receiving unit that outputs a signal, and a detection unit.
The first signal sequence composed of the plurality of the first signals and the second signal sequence composed of the plurality of second signals are calculated, and the first deviation amount is relatively shifted by the first deviation amount. and based on the difference value of the first signal sequence and the second signal sequence, and a calculation unit for calculating a second deviation between said second signal sequence and the first signal sequence,
A control unit that controls the optical system based on the second deviation amount calculated by the calculation unit, and
A focus adjuster equipped with. In the focus adjusting device according to claim 1,
The calculation unit sets a plurality of the first signal string and the second signal string based on the difference value between the first signal string and the second signal string that are relatively shifted by the first deviation amount. A focus adjusting device that divides into a range and calculates the second deviation amount between the first signal string and the second signal string for each range. In the focus adjusting device according to claim 1 or 2.
It further has an image pickup device that captures an image of the subject, and has an image pickup device.
The second deviation amount is a focus adjusting device which is an amount related to a position of an image of the subject formed by the optical system and a focused state of the image sensor. The focus adjusting device according to any one of claims 1 to 3.
The calculation unit calculates the degree of coincidence between the first signal string and the second signal string when the first signal string and the second signal string are relatively shifted with respect to a plurality of shift amounts. A focus adjusting device that calculates the second shift amount based on the plurality of shift amounts and the degree of coincidence corresponding to the shift amount. The focus adjusting device according to any one of claims 1 to 4.
The calculation unit performs the first signal when the first signal string and the second signal string are relatively shifted by the first deviation amount between the first signal string and the second signal string. A focus adjusting device that divides the first signal train and the second signal train into a plurality of ranges when the degree of coincidence between the train and the second signal train is lower than a predetermined value. The focus adjusting device according to any one of claims 1 to 4.
The calculation unit includes each of the plurality of the first signals and each of the plurality of the second signals calculated by relatively shifting the first signal sequence and the second signal sequence by the amount of the first deviation. A focus adjusting device that calculates the average value of a plurality of the difference values, and divides the first signal sequence and the second signal sequence into a range in which the difference value is larger than the average value and a range in which the difference value is smaller than the average value. A plurality of first light receiving units that receive light that has passed through a first region of an optical system that forms an image of a subject and output a plurality of first signals, and light that has passed through a second region of the optical system. A detection unit having a plurality of second light receiving units that receive light and output a plurality of second signals, respectively.
The first deviation amount between the plurality of first signals and the plurality of second signals is calculated, and the plurality of first signals and the plurality of second signals are relatively shifted by the first deviation amount. Based on the difference value between each signal of the plurality of first signals and each signal of the plurality of second signals calculated as described above, the plurality of first signals and the plurality of second signals are each divided into a plurality of ranges. , A calculation unit that calculates a second deviation amount between the plurality of first signals and the plurality of second signals for each range.
A control unit that controls the optical system based on the second deviation amount calculated by the calculation unit, and
A focus adjuster equipped with.

Images