JPH09311269A - Focus detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focus detector capable of efficiently shortening focus detecting cycle regardless of the number of focus detecting areas and the difference of brightness and darkness on a photographic screen in a focus detector performing focus detection for plural focus detecting areas. SOLUTION: This focus detector is provided with an optical system 1 for focus detection which divides and imageforms an object luminous flux reaching plural focus detecting areas on the photographic screen and forms a set of optical images by each focus detecting area, plural photoelectric converting means 2 performing photoelectric conversion by each set of optical images, a control means 3 individually controlling charge accumulating time in accordance with the output level of the plural means 2, a focus calculating means 4 calculating focus information from the output of the plural means 2, and a selecting means 5 selecting the focus detecting area used for focusing among the plural focus detecting areas. The means 3 limits the upper limit of another charge accumulating time in accordance with the charge accumulating time of the selected focus detecting area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detection device for performing focus detection on a plurality of focus detection areas, and more particularly,
The present invention relates to a focus detection device that effectively shortens the focus detection cycle.

[0002]

2. Description of the Related Art In recent years, it is known that a camera focuses on a specific portion on a photographic screen or keeps track of a subject image moving on the photographic screen to focus. This type of camera is equipped with a focus detection device that performs focus detection on a plurality of focus detection areas in order to detect the focus state of the shooting screen in detail.

FIG. 8 is a diagram showing the structure of a focus detecting device of this type. In the figure, a sub-mirror (not shown) is arranged on the optical axis of the photographing optical system 13 of the camera, and a field mask 71 is arranged in the reflection direction of the sub-mirror. The field mask 71 is provided with two openings 70A and 70B corresponding to the two focus detection areas on the photographing screen.

A compound lens in which two condenser lenses 72A and 72B are integrally formed is arranged behind the field mask 71, and a diaphragm mask 75 is arranged behind the compound lens. The aperture mask 75 has openings 73A and 74A for pupil-dividing the light flux passing through the opening 70A and the opening 70.
Apertures 73B and 74B for pupil-dividing the B light flux passing therethrough are provided.

A lens plate 78 is disposed behind the diaphragm mask 75, and separator lenses 76A and 77 for re-imaging the split light beams split into the pupils are arranged on the lens plate 78.
A, 76B and 77B are formed. A charge storage type sensor 79 is arranged behind the lens plate 78, and two pairs of light receiving element arrays 80 and 81 and a light receiving element array 80 are arranged on the charge storage type sensor 79 in alignment with the re-formed optical image. Element array 82, 8
3 is provided.

The input / output of this charge storage type sensor 79 is connected to a microprocessor 85 in the camera. FIG.
FIG. 8 is a diagram showing a conventional focus detection cycle. The conventional focus detection operation will be described below with reference to these drawings. First, the subject light that has passed through the photographing optical system 13 is reflected via the sub-mirror and forms an optical image in the vicinity of the field mask 71. The visual field mask 71 partially extracts an optical image through the openings 70A and 70B. The range thus extracted becomes the focus detection area.

The subject light that has once converged in the vicinity of the field mask 71 becomes a diffused light flux behind the field mask 71. The diaphragm mask 75 divides the diffused light flux into pupils for each focus detection area. Since the divided light fluxes thus pupil-divided start from the same focus detection area, they become a light flux that converges at one location on the re-imaging plane and the positions of which change before and after that.

The lens plate 78 individually orients these divided light beams to form an optical image on the light receiving element arrays 80 to 83. The light receiving element arrays 80 to 83 start accumulating photocharges almost at the same time. The microprocessor 85 independently controls the charge storage time of the light receiving element arrays 80 to 83 according to the brightness of the corresponding focus detection area. That is,
The microprocessor 85 uses the light receiving element array 8 of the previous time.
The next charge accumulation time is set in a range in which the output peak value of 0 to 83 does not exceed the dynamic range of post-processing (for example, AD conversion).

By controlling the charge storage time as described above, the output levels of the light receiving element arrays 80 to 83 are automatically adjusted to appropriate levels. The microprocessor 85 performs a known focus calculation process every time the charge accumulation time elapses, and sequentially calculates the defocus amount.

The microprocessor 85 selects a defocus amount satisfying a predetermined condition (for example, the closest distance) from the plurality of defocus amounts, or selects a defocus amount of a focus detection area manually selected in advance. By doing so, the focus detection area mainly used for focus adjustment and the like is determined.

[0011]

By the way, in such a focus detecting device, when the difference in brightness between the photographing screens is large,
The charge storage time for each light-receiving element array varies greatly in the range of several times to several hundred times.

For example, in the case shown in FIG. 9, the object captured by the pair of light receiving element arrays 80 and 81 is bright, and the other object captured by the pair of light receiving element arrays 82 and 83 is dark. In such a case, the pair of light receiving element rows 8
Although the charge storage time at 0 and 81 is short, the charge storage time at the pair of light receiving element arrays 82 and 83 is long.

Therefore, the time (hereinafter referred to as "focus detection cycle") until the defocus amount is detected after the accumulation of the photocharges in all the focus detection areas is lengthened, and the response time of the focus adjustment is delayed. There was a problem. Also, due to the lengthening of the focus detection cycle, it is not possible to accurately grasp the trend of the defocus amount for a subject whose image plane position fluctuates at high speed, and focus adjustment (predictive drive) is performed in the direction of misregistration. There was a problem that it would end up.

Therefore, an object of the invention as set forth in claim 1 is to provide a focus detection device in which the focus detection cycle is efficiently shortened in order to solve the above-mentioned problems. The invention according to claim 2 is, in addition to the object of claim 1, a focus that can continue to accurately detect the focus information of the imaging target even when an object other than the imaging target crosses the focus detection region for a moment. An object is to provide a detection device.

The third aspect of the present invention, together with the object of the first aspect, is to provide a focus detection device capable of optimally shortening the focus detection cycle.

[0016]

FIG. 1 is a principle block diagram for explaining the invention described in claims 1 to 3. Hereinafter, means for solving the above problems will be described with reference to FIG.

According to the first aspect of the present invention, a plurality of focus detection areas are provided in advance on the photographing screen, the subject light flux reaching each focus detection area is divided and re-imaged, and each focus detection area is divided. A focus detection optical system 1 that forms a set of optical images, a plurality of photoelectric conversion units 2 that performs photoelectric conversion for each set of optical images formed via the focus detection optical system 1, and a plurality of photoelectric conversion units. Depending on the output level of the conversion means 2, a plurality of photoelectric conversion means 2
The control means 3 for individually controlling the charge accumulation time and the output of the plurality of photoelectric conversion means 2 are given, and the focus calculation means 4 for calculating the focus information corresponding to the focus adjustment state based on the phase difference of the image pattern. In the focus detection device including a selection unit 5 that selects a focus detection region used for focus adjustment from a plurality of focus detection regions, the control unit 3 sets the focus detection region selected by the selection unit 5 to the focus detection region. The upper limit of the charge accumulation time in the other photoelectric conversion means 2 is limited according to the charge accumulation time of the corresponding photoelectric conversion means 2.

According to a second aspect of the present invention, in the focus detection apparatus according to the first aspect, the control means 3 controls the focus information corresponding to the focus detection area selected by the selection means 5 to indicate an in-focus vicinity. It is characterized in that the charge accumulation time of the other photoelectric conversion means 2 is limited. The invention described in claim 3 is the focus detection apparatus according to claim 1,
The control means 3 determines the end time of the charge accumulation time in the other photoelectric conversion means 2 with the time at which the focus calculation means 4 calculates the focus information of the “focus detection area selected by the selection means 5” as the time limit. Is characterized by.

(Operation) In the focus detecting apparatus according to the first aspect, the selecting means 5 manually or automatically selects the focus detecting area used for focus adjustment from the plurality of focus detecting areas. The control unit 3 limits the upper limit of the other charge storage time according to the charge storage time of the focus detection area selected by the selection unit 5.

Due to such an action, when the other charge accumulation time is equal to or less than the upper limit value, the time limit is not executed,
The operation is as usual. In this case, since the focus detection cycle is originally short, the above-mentioned problems do not occur. On the other hand, when the other charge accumulation time exceeds the upper limit value, the time limitation is executed. As a result, the focus detection cycle is shortened.

Even in such a case, the charge accumulation time is not limited in the selected focus detection area.
Therefore, for the selected focus detection area, the output level of the photoelectric conversion means 2 is maintained at an appropriate level, and focus information can be detected with high detection accuracy. In the other focus detection areas, the charge accumulation time is limited, so that the output level of the photoelectric conversion unit 2 becomes lower than the appropriate level. However, the other focus detection areas are not directly used for focus adjustment, and therefore the accuracy of detection of focus information is not directly reduced.

In the focus detecting apparatus according to the second aspect, the charge accumulation time of the other photoelectric conversion means 2 is limited only when the focus information of the selected focus detecting area indicates the in-focus vicinity. Therefore, in the case where an object other than the object to be photographed is temporarily located in the focus detection area and the selecting unit 5 erroneously selects the object as the main subject, the charge storage time is until the object is focused. Not limited. Therefore, while the object is out of the focus detection area, it is possible to immediately restart the focus adjustment for the original main subject.

In the focus detecting device according to the third aspect, the photoelectric conversion means 2 can accumulate the photocharges until the focus information is calculated for the selected focus detecting area. Therefore, the charge accumulation time can be set as long as possible for the other photoelectric conversion means 2 while shortening the focus detection cycle.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an embodiment (corresponding to claims 1 to 3). In FIG. 2, the lens barrel 12 is attached to the front surface of the camera body 11, and the operation member 11a for manually selecting the focus detection area is arranged on the rear surface of the camera body 11. A photographing optical system 13 is arranged inside the lens barrel 12.

On the optical axis of the photographing optical system 13, a main mirror 14 and a sub mirror 15 are arranged in order, and a matt surface 16 and a pentaprism 17 are arranged along the reflection direction of the main mirror 14. On the rear surface side of the pentaprism 17, an eyepiece lens 18 and a photometric unit 19 are arranged,
The focus detection unit 20 is arranged in the reflection direction of the sub mirror 15.

The operation member 11a, the photometry unit 19 and the focus detection unit 20 are connected to a microprocessor 21 arranged inside the camera body 11. The focus detection unit 20
Since the internal structure of is the same as the structure shown in FIG. 8, the description will be given using the reference numbers shown in FIG.
Further, regarding the correspondence relationship between the invention according to claims 1 to 3 and the present embodiment, the focus detection optical system 1 includes the visual field mask 7
1, the diaphragm mask 75 and the lens plate 78, the plurality of photoelectric conversion units 2 correspond to the light receiving element arrays 80 and 81 and the light receiving element arrays 82 and 83, and the control unit 3 controls the “charge accumulation time of the microprocessor 21”. The focus calculating means 4 corresponds to the "defocus amount calculating function" in the microprocessor 21, and the selecting means 5 corresponds to the "defocus amount selecting function" in the microprocessor 21.

FIG. 3 is a flow chart for explaining the operation of this embodiment. The operation of this embodiment will be described below with reference to FIGS. 2, 3, and 8. First, when the mirror is down, the subject light is reflected through the main mirror 14 and a subject image is formed on the matt surface 16. This subject image is scattered through the matte surface 16, and then the pentaprism 17,
It is observed through the eyepiece lens 18.

A part of the light scattered by the matte surface 16 is measured by the photometry section 19 to calculate the brightness of two focus detection areas, which will be described later. These brightnesses are transmitted to the microprocessor 21. On the other hand, the light flux that has passed through the light transmitting portion of the main mirror 14 is reflected by the sub mirror 15 and is applied to the focus detection unit 20.

Here, the microprocessor 21 initializes the charge accumulation time for each focus detection area based on the brightness value measured by the photometry section 19 (S1 in FIG. 3).
That is, as shown in FIG. 4, when the logarithmized luminance value Li exceeds the luminance L1, the amplification gain of the corresponding light receiving element array is set to a low gain (hereinafter referred to as “L side”), and then Ti = K1-Li (1) is calculated to obtain the logarithmic charge accumulation time Ti.
Here, the constant K1 is a numerical value that represents an appropriate output level of the light receiving element array in a logarithmic value with the amplification gain set to the L side.

The logarithmized luminance value Li is the luminance L
When it is less than 2, after setting the amplification gain of the corresponding light receiving element array to a high gain (hereinafter referred to as “H side”), Ti = K2-Li (2) is calculated, and the logarithmic charge is calculated. The accumulation time Ti is obtained.
Here, the constant K2 is a numerical value that represents an appropriate output level of the light receiving element array in a logarithmic value in a state where the amplification gain is set to the H side.

Further, the charge accumulation time T calculated by the equation (2)
If i exceeds the predetermined time TMAX, Ti is replaced with the predetermined time TMAX. In addition, this predetermined time TMAX
The replacement by is uniformly performed regardless of whether or not it is the selected focus detection area. Next, the microprocessor 21 receives the light receiving element arrays 80 and 81 and the light receiving element array 82,
The accumulation of the photocharges with respect to 83 is started almost simultaneously. The microprocessor 21 ends the accumulation of the photocharges for each light receiving element row according to the charge accumulation time Ti set for each focus detection area (S2 in FIG. 3).

The microprocessor 21 takes in the output of the light-receiving element array each time the accumulation of the photocharges is completed, amplifies the output based on the preset amplification gain, and then the A /
D conversion is performed to convert into digital data. Well-known correlation calculation processing for calculating the image shift amount is performed on this digital data to calculate the defocus amount (FIG. 3S).
3).

Here, the microprocessor 21 selects the focus detection area corresponding to the closest defocus amount from the defocus amounts obtained for each focus detection area (S4 in FIG. 3). According to the defocus amount of the focus detection area thus selected, the microprocessor 21
The focus detection state is displayed and the lens is driven to adjust the focus (S5 in FIG. 3).

In this state, the microprocessor 21
The next charge storage time is determined as follows. First, using the previous charge storage time Ti, the output peak value Pi of the corresponding light receiving element array, and the constant Ki corresponding to the previous amplification gain, Li = Ki-Ti-LOG (P / Pi) ( 3) is calculated and the previous brightness value Li is calculated. Where the constant P
The value of is selected in a range in which the output peak value Pi after amplification does not exceed the saturation input level of the A / D converter (for example, about 2/3 of the AD conversion range) even if the subject brightness changes.

Next, when the previous amplification gain is on the L side, (3)
When the brightness Li calculated by the formula exceeds the brightness L1, the next amplification gain is set to the L side, and Ti = K1-Li (4) is calculated to calculate the next accumulation time Ti. . Further, when the previous amplification gain is on the L side and the brightness Li obtained by the equation (3) is less than or equal to the brightness L1, the next amplification gain is set on the H side and Ti = K2-Li ... ( 5) is calculated to obtain the next accumulation time Ti.

Further, the charge accumulation time T calculated by the equation (5)
When i exceeds TMAX for a predetermined time, TMA is added to Ti.
Replace with X. The replacement with TMAX for the predetermined time is uniformly performed regardless of whether or not the focus detection area is selected. Furthermore, the previous amplification gain is H
On the side, when the brightness Li obtained by the expression (3) is higher than the brightness L2, the next amplification gain is set to the L side, and the expression (4) is calculated to determine the next accumulation time Ti. .

Further, when the previous amplification gain is on the H side, (3)
When the brightness Li obtained by the formula is lower than the brightness L2, the next amplification gain is set to the H side and the formula (5) is calculated to determine the next accumulation time Ti. In this way, the next charge storage time Ti is calculated for each focus detection area (S6 in FIG. 3).

Next, the microprocessor 21 determines whether or not the absolute value of the defocus amount is less than or equal to a predetermined value (that is, near the in-focus point) for the selected focus detection area (S7 in FIG. 3). If it is determined that the state is out of focus, the process returns to step S2 without limiting the charge accumulation time, and the next accumulation of photocharges is executed.

On the other hand, when it is determined that the object is in focus, the charge accumulation time in the other focus detection areas is compared with the charge accumulation time in the selected focus detection area (FIG. 3S).
8). Here, if the charge accumulation time of the selected focus detection region is longer than the predetermined time, the process returns to step S2 to execute the next accumulation of the photocharges. In such a case, as shown in FIG. 5, during the charge accumulation operation of the selected focus detection area, the charge accumulation operation of the other focus detection areas ends. Therefore, the charge accumulation time in other focus detection areas does not affect the entire focus detection cycle.

On the other hand, when the charge accumulation time of the selected focus detection area is shorter and the next amplification gain in the other focus detection areas is on the L side (FIG. 3S9), the amplification gain is changed to the H side. After recalculating the charge storage time (S10 in FIG. 3), the process returns to step S11. Further, when the charge accumulation time of the selected focus detection area is shorter and the next amplification gain in the other focus detection areas is on the H side (S3 in FIG. 3), the charge accumulation time Ti of the other focus detection areas is set to (Charge storage time of selected focus detection area) +
(Time required for focus calculation processing) (S1 in FIG. 3)
1). In this state, the process returns to step S2 to execute the next accumulation of photocharges.

In such a case, as shown in FIG. 6, the charge accumulation operation is completed for the other focus detection areas, and the charge accumulation operation and the focus calculation operation for the selected focus detection area are completed. Therefore, the focus detection calculation process can be started for other focus detection regions without a time interval. As a result, the charge accumulation time in the other focus detection areas does not affect the entire focus detection cycle, and the responsiveness of the focus detection operation does not deteriorate.

By the operation described above, in this embodiment, according to the charge accumulation time of the selected focus detection area,
Since the upper limit of other charge storage time is appropriately limited,
The focus detection cycle can be effectively shortened. Therefore, the focus detection cycle does not become longer than necessary regardless of the difference between the brightness of the photographic screen and the response time of focus adjustment can be shortened.

Further, since the focus detection cycle is shortened, the focus information detected per unit time increases. Therefore, even for a subject whose image plane position changes abruptly, it is possible to accurately and precisely grasp the trend of focus information, and it is possible to accurately perform focus adjustment (predictive driving). Furthermore, since the charge accumulation time is not limited at all in the selected focus detection area, the output level of the light receiving element array is maintained at an appropriate level. Therefore, for the selected focus detection area, focus information is detected with high detection accuracy, and it is possible to maintain high position accuracy of focus adjustment and the like.

Regarding the other focus detection areas,
Since the charge storage time is limited, the output level may be below the proper level. However, the other focus detection areas are not directly used for the focus adjustment, and therefore the position accuracy of the focus adjustment is not directly deteriorated. Further, with respect to the other focus detection areas, the output level rarely saturates, and the charge accumulation time required to obtain an appropriate level can be calculated reliably and stably.

Further, only when the focus information of the selected focus detection area indicates the in-focus vicinity, the charge accumulation time of the other focus detection areas is limited. Therefore, even in the case where an object other than the shooting target is temporarily located in the focus detection area and the object is erroneously determined to be the main subject,
There is no limit to the charge storage time until the object is in focus. Therefore, while the object is out of the focus detection area, it is possible to immediately restart the focus adjustment for the original main subject.

Further, at the same time the focus information is calculated for the selected focus detection area, the photocharge accumulation is completed for the other focus detection areas. Therefore, the charge accumulation time can be set as long as possible in other focus detection areas within the range where the focus detection cycle does not become long.
Further, in the case where the main subject moves to another focus detection area, the luminance of the main subject hardly changes.
Therefore, if focus detection is performed in the charge accumulation time of the focus detection area selected last time, the output level can be adjusted to an appropriate level even in the focus detection area of the moving destination. Therefore, even in such a case, focus information can be detected with high accuracy.

In the above-described embodiment, the case where the focus detection area is automatically selected has been described, but the present invention is not limited to this, and when the focus detection area is manually selected as shown in FIG. May be applied to. Further, in the above-described embodiment, the case where focus detection is performed on two focus detection areas has been described, but the present invention is not limited thereto, and focus detection that performs focus detection on two or more focus detection areas. It may be applied to the device.

[0048]

As described above, in the focus detecting apparatus according to the first aspect, the upper limit of the other charge accumulating time is limited according to the charge accumulating time of the selected focus detecting area. Can be shortened. Therefore, the response time of the focus adjustment can be effectively shortened regardless of the "set number of focus detection areas" and the "brightness / darkness difference of the photographing screen".

Further, since the focus detection cycle is shortened and the focus information detected per unit time is increased, even for a subject whose image plane position changes abruptly,
The trend of focus information can be grasped accurately and meticulously.
Therefore, the focus adjustment (predictive driving) can be accurately performed. Furthermore, the charge accumulation time is not limited at all for the selected focus detection area. Therefore, for the selected focus detection area, the output level of the photoelectric conversion means is maintained at an appropriate level, and focus information can be detected with high detection accuracy.

Regarding other focus detection areas,
Since the charge accumulation time is time limited, the output level of the photoelectric conversion means is below the proper level. However, the other focus detection areas are not directly used for focus adjustment, and therefore the accuracy of detection of focus information is not directly reduced. Further, in the other focus detection areas, the charge storage time is limited, so that the possibility that the output level of the photoelectric conversion means suddenly exceeds the saturation level is greatly reduced. Therefore, for other focus detection areas,
It is possible to correctly detect the peak value of the output level, and it is possible to reliably and stably calculate the “charge storage time required to obtain the appropriate level”.

Further, in the case where the main subject moves to another focus detection area, the luminance of the main subject hardly changes. Therefore, if focus detection is performed in the charge accumulation time of the focus detection area selected last time, the output level can be adjusted to an appropriate level even in the focus detection area of the moving destination. Therefore, even when the main subject moves in this way, it becomes possible to detect focus information with high accuracy.

In the focus detecting apparatus according to the second aspect, the charge accumulating time of the other focus detecting areas is limited only when the focus information of the selected focus detecting area indicates the in-focus vicinity. Therefore, in the case that an object other than the object to be photographed is temporarily located in the focus detection area and that object is mistakenly selected as the main subject, the charge accumulation time is limited until the object is focused. Not done. Therefore, it is possible to continue to detect the focus information with high accuracy for the original main subject, and the object can move out of the focus detection area, and the focus adjustment can be immediately restarted for the original main subject.

In the focus detecting device according to the third aspect, photoelectric charges are accumulated in the other photoelectric conversion means until focus information is calculated for the selected focus detecting area. Therefore, the charge storage time can be set as long as possible for the other photoelectric conversion means within the range where the focus detection cycle does not become long.

[Brief description of drawings]

FIG. 1 is a principle block diagram for explaining the invention described in claims 1 to 3.

FIG. 2 is a diagram showing an embodiment (corresponding to claims 1 to 3).

FIG. 3 is a flowchart illustrating an operation of the present embodiment (when a focus detection area is automatically selected).

FIG. 4 is a diagram illustrating a charge accumulation time calculation process.

FIG. 5 is a diagram showing a focus detection cycle of the embodiment.

FIG. 6 is a diagram showing a focus detection cycle of the embodiment.

FIG. 7 is a flowchart illustrating an operation of the embodiment (when manually selecting a focus detection area).

FIG. 8 is a diagram showing an internal configuration of a focus detection unit.

FIG. 9 is a diagram showing a conventional focus detection cycle.

[Explanation of symbols]

 1 focus detection optical system 2 photoelectric conversion means 3 control means 4 focus calculation means 5 selection means 11 camera body 11a operating member 12 lens barrel 13 photographing optical system 14 main mirror 15 sub-mirror 16 matte surface 17 pentaprism 18 eyepiece lens 19 photometric section 20 Focus Detection Section 21 Microprocessor 70A Aperture 71 Field Mask 72A Condenser Lens 75 Aperture Mask 78 Lens Plate 79 Charge Storage Sensor 85 Microprocessor

Claims (3)

[Claims] 1. A plurality of focus detection areas are provided in advance on a photographing screen, a subject light flux reaching each focus detection area is divided and re-imaged, and a set of optical images is formed for each focus detection area. Focus detection optical system, a plurality of photoelectric conversion means for performing photoelectric conversion for each set of optical images formed via the focus detection optical system, depending on the output level of the plurality of photoelectric conversion means , Control means for individually controlling the charge accumulation time of the plurality of photoelectric conversion means, and outputs of the plurality of photoelectric conversion means are provided, and based on the phase difference of the image pattern, focus information corresponding to the focus adjustment state is obtained. In a focus detection device comprising a focus calculation means for calculating and a selection means for selecting a focus detection area used for focus adjustment from the plurality of focus detection areas, the control means is selected by the selection means. Focus detection area A focus detection device characterized in that the upper limit of the charge accumulation time in other photoelectric conversion means is limited according to the charge accumulation time of the photoelectric conversion means corresponding to the region. 2. The focus detection device according to claim 1, wherein the control unit is a photoelectric conversion device other than the photoelectric conversion device only when the focus information corresponding to the focus detection region selected by the selection unit indicates the focus vicinity. A focus detection device characterized in that the charge storage time of the conversion means is limited. 3. The focus detection device according to claim 1, wherein the control unit sets the time when the focus calculation unit calculates the focus information of the “focus detection region selected by the selection unit” as a time limit.
A focus detection device characterized in that the end time of the charge accumulation time in other photoelectric conversion means is determined.