JP2008015273A - Camera system and digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera system and a digital camera capable of performing accurate focus adjustment without giving stress to a user regardless of the optical characteristic of an interchangeable lens to be used and a focus lens driving mechanism. <P>SOLUTION: A control part 16 decides whether or not the interchangeable lens 2 is fit for the focus adjusting system of a camera body 1 based on information on the interchangeable lens 2 transmitted from the interchangeable lens 2. When the interchangeable lens 2 is not fit for the focus adjustment system of the camera body 1, a mode is set to a manual focus mode in which the user manually performs focus adjustment temporarily, and when the peak value of a focusing evaluated value is detected in the manual focus mode, the mode is set to an automatic focus mode in which focusing control is automatically performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a camera system and a digital camera having an autofocus (AF) function.

  Conventionally, a TTL (Through The Lens) phase difference AF mechanism is often used as an AF mechanism in a single-lens reflex camera using a silver salt film that is an interchangeable lens type camera or a digital single-lens reflex camera. In this case, a defocus detection mechanism for performing TTL phase difference AF is provided in the single-lens reflex camera body. The focusing lens provided in the lens barrel of the interchangeable lens that can be attached to and detached from the single-lens reflex camera is driven by a motor provided in the lens barrel of the interchangeable lens or in the single-lens reflex camera body. Perform the adjustment operation.

  On the other hand, in a compact digital camera, a video camera, etc., an AF evaluation value is obtained by performing contrast detection with a high-frequency component of a signal of an image sensor while scanning a focusing lens, and the AF evaluation value is a peak value. A so-called imager AF that searches for the lens position of the focus lens is often used.

  In general, the TTL phase difference AF is faster than the imager AF, and the imager AF is more accurate than the TTL phase difference AF and is provided with an optical system for focus detection required for performing the TTL phase difference AF. There is no need. Based on such characteristics, the TTL phase difference AF and the imager AF are properly used depending on the type of camera.

  There is a great need for imager AF in a digital single-lens reflex camera. This can be seen from the fact that, for example, Patent Documents 1 to 3 disclose a technique related to a digital camera having an interchangeable lens type and an imager AF function.

Japanese Patent Application Laid-Open No. 2004-228688 improves user convenience by automatically changing from the manual focus (MF) mode to the AF mode when the AF evaluation value by the imager AF exceeds a predetermined threshold. Technology is disclosed.
JP-A-6-6660 JP-A-6-181532 JP-A-8-223469 JP 2002-107609 A

  By the way, in the interchangeable lens single-lens reflex camera, many interchangeable lenses have been put on the market and are already in widespread use for single-lens reflex cameras using a silver salt film. Here, these already widely used interchangeable lenses are designed to support TTL phase difference AF. In other words, the focus adjustment mechanism of the focus lens in the interchangeable lens barrel is designed as a system that drives a lens drive amount corresponding to the detected defocus amount. Specifically, a direct current motor (DC motor) is often used as a drive source for adjusting the focus in the interchangeable lens barrel. On the other hand, a stepping motor is optimal as a driving source for the focus lens in the imager AF, and many stepping motors are actually employed.

  Therefore, when the focus detection mechanism on the camera body side is the imager AF, if the imager AF is executed using an interchangeable lens designed to cope with the TTL phase difference AF, the controllability is significantly lowered. This decrease in controllability is due to the fact that the stop accuracy of the DC motor is inferior to the stop accuracy of the stepping motor.

  That is, when the focus detection mechanism on the camera body side is an imager AF, the use of the above-described interchangeable lens as an interchangeable lens does not necessarily enable high-speed and high-precision focus adjustment.

  For example, when executing the imager AF, it takes several seconds or more to focus the focus lens in the interchangeable lens from the closest lens position to the infinity lens position (infinite object). There are telephoto type interchangeable lenses and macro type interchangeable lenses. In general, humans feel stressed by waiting for a long time without performing any operation on their own as in AF.

  Here, the techniques disclosed in Patent Documents 1 to 4 are not techniques invented in consideration of such problems. Therefore, the techniques disclosed in Patent Documents 1 to 4 do not solve the above problem.

  The present invention has been made in view of the above circumstances, and can perform high-precision focus adjustment without giving stress to the user regardless of the optical characteristics of the interchangeable lens used and the focus lens driving mechanism. An object is to provide a system and a digital camera.

  In order to achieve the above object, a camera system according to a first aspect of the present invention is a camera system including a camera and a lens unit that can be attached to and detached from the camera, and the lens unit includes the lens. Storage means for storing information relating to the characteristics of the unit; a focus lens for adjusting the focal position; and the focus lens according to a movement operation of the focus lens by a photographer or based on an instruction signal from the camera And a lens control unit that changes the focus position of the lens unit, and the camera detects a contrast of the subject image and calculates a focus evaluation value representing a focus degree. Based on the value calculation means and the focus evaluation value, the focus lens is controlled to automatically move to the focus position. Auto focus means for generating an indication signal and transmitting it to the lens control means, auto focus mode for executing focus adjustment of the focus lens by the auto focus means, or focus lens by the photographer for focus adjustment of the focus lens Mode setting means for setting the manual focus mode to be executed by the moving operation, and detecting that the focus evaluation value has peaked in the change of the focus evaluation value according to the movement of the focus lens. A peak detection unit, and a determination unit that determines whether or not the lens unit is suitable for focus control by the autofocus unit based on information on the characteristics of the lens unit stored in the storage unit. The mode setting means causes the determination means to cause the lens unit to be moved by the autofocus means. When it is determined that it is not suitable for focus control, the manual focus mode is set. Further, when the peak of the focus evaluation value is detected by the peak detection means in the manual focus mode, the auto focus mode is set. It is characterized by setting to.

  In order to achieve the above object, a digital camera according to a second aspect of the present invention is a digital camera in which a lens unit having a focus lens for adjusting a focal position is detachable, and detects the contrast of a subject image. A focus evaluation value calculating means for calculating a focus evaluation value representing the degree of focus, and an instruction signal for controlling the focus lens to automatically move to a focus position based on the focus evaluation value Auto focus means for generating and transmitting to the lens unit, and auto focus mode in which focus adjustment of the focus lens is executed by the auto focus means, or focus lens focus adjustment by the photographer moving operation of the focus lens Mode setting means for setting the manual focus mode to be executed, and the lens unit is focused by the automatic focus means. A determination unit that determines whether or not the control unit is suitable for control, and the mode setting unit is configured to determine that the lens unit is not suitable for focusing control by the automatic focusing unit by the determination unit. The manual focus mode is set, and when it is determined that the focus control is suitable for the auto focus means, the auto focus mode is set.

  In order to achieve the above object, a digital camera according to a third aspect of the present invention is a digital camera in which a lens unit having a focus lens for adjusting a focal position is detachable, and detects the contrast of a subject image. A focus evaluation value calculating means for calculating a focus evaluation value representing the degree of focus, and an instruction signal for controlling the focus lens to automatically move to a focus position based on the focus evaluation value Generating and transmitting to the lens unit, and an autofocus mode in which focus adjustment of the focus lens is performed by the autofocus means, or an operation of moving the focus lens by a photographer for focus adjustment of the focus lens Mode setting means for setting the manual focus mode to be executed according to the above, and the focusing according to the movement of the focus lens Based on the peak detection means for detecting that the in-focus evaluation value has peaked in the change in value, and the information on the characteristics of the lens unit sent from the lens unit, the lens unit Determining means for determining whether or not it is suitable for focusing control by the means, and the mode setting means determines that the lens unit is not suitable for focusing control by the automatic focusing means by the determining means. The manual focus mode is set, and when the peak of the focus evaluation value is detected by the peak detection means in the manual focus mode, the automatic focus mode is set. To do.

  According to the present invention, it is possible to provide a camera system and a digital camera capable of performing high-precision focus adjustment without giving stress to a user without depending on the optical characteristics of the interchangeable lens used and the focus lens driving mechanism. it can.

[First embodiment]
Hereinafter, a camera system and a digital camera according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a system configuration of a digital camera according to the first embodiment of the present invention. In the first embodiment, a digital single-lens reflex camera will be described as a digital camera.

  First, in FIG. 1, reference numeral 1 denotes a camera body. Reference numeral 2 is an interchangeable lens as a lens unit.

  Here, the interchangeable lens 2 has a photographing lens system 3, a lens driving unit 4, a lens control unit 5, a memory 5A, a focus ring encoder 6, a focus ring 9, and a lens position encoder 15. is doing.

  The photographing lens system 3 includes a focus lens 3A. During focus adjustment, focus adjustment is performed by driving the focus lens 3A. The lens driving unit 4 is a lens driving unit for adjusting the focus lens 3A in the optical axis direction. The lens control unit 5 is a lens control unit for communicating with the camera body 1 and for controlling the lens driving unit 4. The memory 5A is a memory that stores information related to the characteristics of the interchangeable lens 2.

  The lens position encoder 15 is an encoder that generates a pulse signal according to the movement of the focus lens 3 </ b> A and outputs the pulse signal to the lens control unit 5.

  The lens control unit 5 recognizes the position of the focus lens 3A by counting the output pulses of the lens position encoder 15.

  The focus ring 9 is formed in an annular shape on the exterior of the interchangeable lens 2. When the digital single-lens reflex camera is set to the manual focus (MF) mode, when the focus ring 9 is rotated by the user, the focus ring encoder 6 depends on the rotation amount and the rotation direction. The pulse signal is generated and the pulse signal is output to the lens control unit 5.

  Although not described in detail here since it is not an essential part of the present invention, a method for detecting the rotation direction of the focus ring 9 based on the phases of two encoder outputs is generally known. In such a method, the lens control unit 5 detects the output pulse of the focus ring encoder 6 and converts it into the rotation amount and the rotation direction of the focus ring 9, and the lens driving unit corresponding thereto. MF operation is performed by moving the focus lens 3 </ b> A via 4.

  By the way, the camera body 1 includes an image sensor 7, an LCD panel 10, a viewfinder optical system 11, a release switch 12, an image processing unit 13, a focus detection unit 14, and a control unit 16. .

  The LCD panel 10 is an LCD panel for an electronic viewfinder with a built-in backlight. The finder optical system 11 is a member for a user to observe the LCD panel 10.

  The image processing unit 13 performs white balance, luminance processing, color matrix processing, and the like on the video signal output from the image sensor 7 to form image data that is a captured image and image data for the viewfinder. In addition to the formation of the image data, the image processing unit 13 processes the video signal output from the image sensor 7 to acquire image information including a luminance signal.

  The viewfinder image data formed by the image processing unit 13 is sent to the LCD panel 10 and displayed on the LCD panel 10. The image data for the viewfinder is observed by the user through the viewfinder optical system 11. Further, image data that is a captured image is stored in a nonvolatile memory (not shown) or the like.

  Further, the image processing unit 13 also generates a drive control signal for the image sensor 7 based on a reference clock (not shown) sent from the control unit 16 described later. Specifically, the image processing unit 13 is a timing signal for integration start / end (exposure start / end) in the image sensor 7, and a readout control signal (horizontal synchronization signal, vertical synchronization signal VD, light reception signal) of each pixel. A clock signal such as a transfer signal is generated, and these signals are output to the image sensor 7.

  Here, the image processing unit 13 also outputs the vertical synchronization signal VD to the focus detection unit 14, the control unit 16, and the lens control unit 5. The lens control unit 5 outputs a signal VDP that matches the vertical synchronization signal VD via a lens contact unit 8 described later.

  The lens contact portion 8 is a lens contact portion to which a communication line or the like between the control portion 16 provided in the camera body 1 and the lens control portion 5 provided in the interchangeable lens 2 is coupled. is there. The lens contact portion 8 is used for connection of a plurality of power sources including a lens power source supplied from the camera body 1 to the interchangeable lens 2 and a plurality of signals including a clock / data signal for communication and a vertical synchronization signal. It has a plurality of contacts required for transmission.

  The focus detection unit 14 calculates an AF evaluation value representing the degree of focus based on the luminance signal obtained from the image processing unit 13, and outputs the AF evaluation value to the control unit 16. The control unit 16 is a member that controls the camera body 1 and the interchangeable lens 2 as a whole. The control unit 16 has a counter (not shown) therein.

  In the camera according to the first embodiment, the release button (not shown) is a two-stage push button, and the first release switch (hereinafter referred to as 1RSW) is turned on when pressed halfway. Then, a focus detection operation described later is performed. Further, when the release button (not shown) is fully pressed, a second release switch (hereinafter referred to as 2RSW) is turned on, and a photographing operation described later is performed. Here, the release switch 12 corresponds to the 1RSW.

  Hereinafter, the imager AF will be described with reference to FIGS. 2 and 3.

  First, as shown in FIG. 2, a high-pass filter (HPF) 131, an A / D converter 132, a focus detection area selection gate 133, and an adder 134 are connected and provided in this order in the focus detection unit 14. It has been. Here, each component provided in the focus detection unit 14 is a circuit block for obtaining an AF evaluation value.

  The image processing unit 13 inputs a luminance signal generated from the video signal of the image sensor 7 to the HPF 131 of the focus detection unit 14. The luminance signal is processed in the image processing unit 13 as follows.

  First, the high-frequency component contained in the luminance signal is extracted from the luminance signal by the HPF 131. The extracted high-frequency component is included in proportion to the sharpness of the image. Therefore, by integrating this high-frequency component for a predetermined image range, the level of average image sharpness in the image range can be quantified.

  Next, the high frequency component that has passed through the HPF 131 is converted into a digital signal by the A / D converter 132 and input to the focus detection area selection gate 133. The focus detection area selection gate 133 is a circuit that extracts only signals corresponding to a plurality of focus detection areas on the imaging screen. Therefore, the focus detection area selection gate 133 extracts only information relating to the subject imaged in the focus detection area. The focus detection area corresponds to the predetermined image range to be integrated.

  Here, the focus detection area may be a focus detection area selected from a plurality of focus detection areas based on a predetermined selection algorithm (for example, the closest selection algorithm). Of course, the focus detection area selected by the user among the plurality of focus detection areas may be adopted.

  The digital signal extracted by the focus detection area selection gate 133 is input to the adder 134. In the adder 134, the digital signal for one frame is integrated (integrated). The value accumulated by the adder 134 is input to the control unit 16 as an AF evaluation value indicating the sharpness of the image. The control unit 16 can perform imager AF, which is a known hill-climbing autofocus, using the AF evaluation value calculated in this way.

  Here, when the imager AF is performed, the control unit 16 moves the focus lens 3A by the lens driving unit 4 via the lens control unit 5 and acquires position information of the focus lens 3A. An AF evaluation value is input from the adder 134 to obtain an AF evaluation coordinate value ((P1, H1) (P2, H2) (P3, H3)) as shown in FIG.

  Then, the control unit 16 calculates the lens position of the focus lens 3A when the AF evaluation value becomes the maximum value, that is, the peak value, by interpolation calculation or the like using the AF evaluation coordinate value. Thereafter, the focus lens 3A is moved to the focus target position PM, which is the lens position when the AF evaluation value reaches the peak value.

  The image processing unit 13 outputs the luminance signal to the focus detection unit 14 and sends a synchronization signal to the focus detection area selection gate 133, the adder 134, and the control unit 16 in accordance with the video signal. Output.

  Further, regarding the selection of the focus detection area, for example, a focus detection area selected based on a predetermined selection algorithm (for example, selection of the nearest focus detection area) among a plurality of focus detection areas may be adopted. Of course. Of course, the focus detection area selected by the user may be adopted.

  Hereinafter, operation control by the control unit 16 of the digital camera according to the first embodiment will be described with reference to a flowchart shown in FIG.

  First, when a power (not shown) provided in the camera body 1 is turned on by a user, the control unit 16 in the camera body 1 communicates with the lens control unit 5 in the interchangeable lens 2 ( Step S100). Specifically, in step S100, the control unit 16 reads out various data stored in the memory 5A in the interchangeable lens 2, and the data is stored in a storage unit (not shown) in the control unit 16. It is a step to memorize.

  The communication between the control unit 16 in the camera body 1 and the lens control unit 5 in the interchangeable lens 2 is hereinafter referred to as body / lens communication, and the body / lens communication in step S100 is referred to as body / lens communication.・ This is referred to as initial lens communication. In the body / lens communication, data relating to the interchangeable lens 2 to be communicated includes information on the lens type, focal length, shootable distance, total number of focus pulses, motor type, and the like of the interchangeable lens 2 and various types of AF. Information such as the correction value can be given.

  When the body / lens initial communication process in step S100 is completed, the release button is pressed halfway by the user, and the process waits until the release switch 12 (1RSW) is turned on (step S101). Here, the body / lens communication is repeatedly executed until the release switch 12 is turned on (step S102). In the body-lens communication in step S102, the communication from the interchangeable lens 2 to the camera body 1 includes the state of the focus lens 3A that changes every moment, such as a change in the focal length of the focus lens 3A due to zooming. The communication of the data shown can be mentioned. The communication from the camera body 1 to the interchangeable lens 2 can include communication such as command communication for setting / releasing the MF mode.

  When the 1RSW is turned on, the step S101 is branched to YES, and the focusing operation by the autofocus starts. That is, the lens type of the interchangeable lens 2 is determined (step S103). Specifically, in the lens type determination in step S103, the lens type data acquired by the body / lens initial communication in step S100 is referred to and whether or not the lens type of the interchangeable lens 2 is the lens type 0 or not. Is determined (step S104). There are two lens types (0, 1) to be discriminated in step S104. The interchangeable lens 2 that is the lens type 0 is an interchangeable lens suitable for the imager AF, and the interchangeable lens 2 that is the lens type 1 is the imager. This is an interchangeable lens that is not suitable for AF (details of the lens type will be described later). When step S104 is branched to YES, the process proceeds to step S110 described later.

  On the other hand, when step S104 is branched to NO, an MF mode setting command is transmitted to the lens control unit 5 in the interchangeable lens 2 (step S105). Subsequently, a peak search process for searching for the peak value of the AF evaluation value is performed (step S106). The details of the peak search process in step S106 will be described later in detail with reference to the flowchart shown in FIG. 6. However, when the release button half-pressed during the peak search process is released, The peak search process is terminated. This is to determine that the focus operation has been interrupted by the user (photographer).

  Then, it is determined whether or not the 1RSW is turned off (step S107). When step S107 is branched to YES, an MF mode end command, which is a command to end the MF mode, is transmitted to the lens control unit 5 in the interchangeable lens 2 (step S108). Then, the process returns to step S101. If step S107 is branched to NO, it is determined whether or not the peak of the AF evaluation value has been detected as a result of the peak search process in step S106 (step S109). When step S109 is branched to YES, the process proceeds to step S110 described later.

  Step S110, which is shifted when step S104 is branched to YES and step S109 is branched to YES, is a step of executing the imager AF. Details of the imager AF process in step S110 will be described later with reference to the flowchart shown in FIG. Subsequently, it is determined whether or not an in-focus state is obtained as a result of the imager AF in step S110 (step S111). When step S111 is branched to YES, an in-focus display indicating the in-focus state is displayed on the LCD panel 10 by the image processing unit 13 (step S112).

  By the way, when step S109 is branched to NO and when step S111 is branched to NO, a display indicating that the subject is out of focus is displayed on the LCD panel 10 by the image processing unit 13 (step S113). ). Then, after the processing in step S112 or step S113 is completed, when shooting is instructed by the user pressing the release button fully or the like, shooting is performed based on a normal shooting sequence (step S114). When the process in step S114 is completed, the process waits until the release switch 12, that is, the 1RSW is turned off (step S115). If it is determined in step S115 that the 1RSW is OFF, the process returns to step S101.

  As described above, in the first embodiment, when the interchangeable lens 2 is the lens type 0 that is an interchangeable lens suitable for the imager AF, the AF is performed only by the imager AF. When the interchangeable lens 2 is an interchangeable lens that is not suitable for the imager AF, the camera operation mode is set to the MF mode, and the AF evaluation value and the change in the lens position of the focus lens 3A according to the user's MF operation are set. Are continuously detected to find the peak value of the AF evaluation value. If the peak value of the AF evaluation value can be detected, the imager AF is executed based on the peak value of the AF evaluation value at the time of detection and the lens position information of the focus lens 3A.

  Hereinafter, the lens type of the interchangeable lens 2 will be described.

  In order to perform imager AF that does not give stress to the user, it is necessary to shorten the time required for focus adjustment to some extent (for example, 1 second or less). If the time required for focus adjustment becomes extremely long, problems such as missing a photo opportunity or determining that the camera is broken by the user occur.

  In view of such circumstances, the lens type of the interchangeable lens is determined from the viewpoint of the time required for focus adjustment. That is, when the time required for focus adjustment, that is, the driving time of the focus lens becomes longer than the predetermined time, the interchangeable lens moves the focus lens while acquiring the AF evaluation value and searches for the peak value of the AF evaluation value. Based on the idea that it is not suitable for the imager AF, the lens type is determined as follows.

  Specifically, an interchangeable lens in which the focus lens drive time from infinity to the closest distance in the entire photographing distance range is within a predetermined time is set as a lens type 0 that is an interchangeable lens suitable for the imager AF. In addition, an interchangeable lens in which the focus lens driving time from the infinity to the closest distance in the entire photographing distance range is a predetermined time or longer is referred to as a lens type 1 that is an interchangeable lens that is not suitable for the imager AF.

  Here, as an interchangeable lens of lens type 0, for example, a wide-angle lens having a short focal length can be exemplified. This interchangeable lens of lens type 0 can be driven in a sufficiently short time even if the focus lens is scanned over the entire photographing distance range by the imager AF, so that the focus adjustment is performed only by the high-precision imager AF.

  Examples of the interchangeable lens of the lens type 1 include a macro lens having a high photographing magnification such as an equal magnification macro, a telephoto lens having a long focal length, and the like. The lens type 1 interchangeable lens requires a longer time for focus adjustment than the lens type 0 interchangeable lens using only the imager AF. Therefore, when an interchangeable lens of lens type 1 is used, coarse adjustment is performed by MF operation by the user, and fine adjustment is performed by the imager AF. Thereby, both shortening of time and high accuracy in focus adjustment are achieved.

  Hereinafter, the focus detection operation by the imager AF in step S110 will be described with reference to the flowchart shown in FIG.

  First, it is determined whether or not peak search detection has been executed in step S106 (step S200). As described above, the details of the peak search process will be described later in detail with reference to the flowchart shown in FIG. When step S200 is branched to YES, the scan range of the imager AF is set (step S201). Here, the scan range is set to ΔX before and after the center position of the lens position of the focus lens 3A obtained by the peak search when the AF evaluation value becomes the peak value. This ΔX is a predetermined scanning range so that the focusing operation can be performed with sufficiently high accuracy and high speed by the imager AF, and is stored in the memory 5A in the interchangeable lens 2, and is controlled by the control unit 16. It is read and used. Note that ΔX is appropriately changed depending on parameters such as the focal length of the interchangeable lens 2, the position (distance) of the focus lens 3A, the reliability of peak search, and the like.

  On the other hand, when step S200 is branched to NO, the scan range of the focus lens 3A is set to the entire focus lens movable range, that is, from the closest distance to infinity (step S202). The process in step S202 is a process that takes into consideration that the focus lens 3A is not likely to be located near the focus because the peak search has not been executed in advance.

  After transmitting the scan range set in step S201 or step S202 in this way to the lens control unit 5 through body / lens communication, a predetermined command is transmitted to the lens control unit 5, and the lens control unit The lens driving unit 4 is controlled via 5 to move the focus lens 3A to the end of the scan range closer to the camera body 1 (step S203).

  Then, the lens drive command of the imager AF is transmitted to the lens control unit 5 to start the scanning operation of the focus lens 3A (step S204). Further, the image processing unit 13 performs exposure (EXP) of the image sensor 7 and reading of the video signal (READ) at a predetermined timing from the generation of the vertical synchronization signal VD, and image information including a luminance signal. , And an AF evaluation value is calculated and fetched based on the luminance signal by the focus detection unit 14 (step S205).

  Subsequently, it waits for the rising edge of the vertical synchronizing signal VD from the image processing unit 13 (step S206). When the rising edge of the vertical synchronizing signal VD is detected, the lens of the focus lens 3A transmitted from the lens control unit 5 is detected. The position is received (step S207). Then, the AF evaluation value acquired in step S205 and the lens position of the focus lens 3A acquired in step S207 are stored in an unillustrated storage unit as an AF evaluation value history (step S208). The relationship between the lens position of the focus lens 3A and the AF evaluation value is as described above with reference to FIG.

  Thereafter, it is determined with reference to the AF evaluation value history whether the focal point (the peak value of the AF evaluation value) has passed (step S209). If it is determined in step S209 that the focal point (the peak value of the AF evaluation value) has not been passed, it is determined whether or not the scanning range set in step S201 or step S202 has been completely scanned (step S209). Step S210). If it is determined in step S210 that the entire scan range has not been scanned, the area to be scanned remains, and the process returns to step S205.

  In the loop from step S205 to step S210, the focus lens 3A is continuously driven, and the peak search of the imager AF can be performed by repeating the processing from step S205 to step S210. .

  By the way, if it is determined in step S209 that the focal point (the peak value of the AF evaluation value) has been passed, a command for causing the lens control unit 5 to stop driving the focus lens 3A through body / lens communication. Is transmitted to stop the driving of the focus lens 3A (step S211).

  Subsequently, referring to the AF evaluation value history, the lens position PM (see FIG. 3) of the focus lens 3A when the AF evaluation value reaches the peak value is obtained in detail by interpolation processing, and the above-mentioned lens body communication is performed by body / lens communication. The focus lens 3A is moved to the lens position PM by the lens driving unit 4 via the lens control unit 5 (step S212).

  Thereafter, the peak value of the AF evaluation value, which is the result of the imager AF, and the in-focus state are stored in a storage unit (not shown) (step S213), the imager AF process is terminated, and the main flowchart of FIG. Return to the routine.

  If it is determined in step S210 that the entire scan range has been scanned, the focal point (the peak value of the AF evaluation value) is not obtained (NO branch in step S209), and the process in the scan range is performed. Since the process is completed (NO branch in step S210), the focus lens 3A is moved to the initial position of the scan range (step S214). Then, the fact that the imager AF cannot be detected is stored in a flag or the like (step S215), the process is terminated, and the process returns to the flowchart shown in FIG. 4, which is the main routine.

  Hereinafter, the operation control of the peak search process in step S106 will be described with reference to the flowchart shown in FIG.

  First, it is determined whether or not the release button is not pressed at all, that is, whether or not the release switch 12 (1RSW) is OFF (step S300). When step S301 is branched to YES, the peak search process is terminated and the process returns to the flowchart shown in FIG. 4 which is the main routine. This is to determine that the focus operation has been interrupted by the user (photographer).

  On the other hand, when step S300 is branched to NO, the image processing unit 13 executes exposure (EXP) of the image sensor 7 and reading of the video signal (READ) from the generation of the vertical synchronization signal VD and outputs the luminance signal. Image information is generated, and the focus detection unit 14 performs AF evaluation value calculation (IAF) to calculate an AF evaluation value at a predetermined timing (step S301). Then, it waits for the rising edge of the vertical synchronization signal VD output from the image processing unit 13 (step S302).

  If the rising edge of the vertical synchronization signal VD is detected in step S302, the lens position of the focus lens 3A transmitted from the lens control unit 5 is received by body / lens communication (step S303). Then, the AF evaluation value acquired in step S301 and the lens position of the focus lens 3A acquired in step S303 are stored in an unillustrated storage unit as an AF evaluation value history (step S304). The relationship between the lens position of the focus lens 3A and the AF evaluation value is as shown in FIG. 10A (details will be described later).

  Thereafter, referring to the AF evaluation value history, it is determined whether or not the peak detection has been performed by passing through the peak value of the AF evaluation value (step S305). When step S305 is branched to YES, the peak value of the AF evaluation value, which is the result of the peak search, and the lens position of the focus lens 3A when the AF evaluation value reaches the peak value are stored in a storage unit (not shown). Store (step S308), end the peak search process, and return to the flowchart shown in FIG. 4, which is the main routine.

  On the other hand, when step S305 is branched to NO, that is, when the peak of the AF evaluation value is not detected, it is determined whether or not a predetermined time limit in the peak search process has elapsed (step S306). ). The time is measured using a counter (not shown) provided in the control unit 16. That is, the time is measured by referring to the value output by the count. By the way, when step S306 is branched to NO, the process returns to step S300.

  When step S306 is branched to YES, the peak value of the AF evaluation value is not obtained (branch to NO in step S305), and when a predetermined limit time has elapsed (branch to YES in step S306). Therefore, the fact that peak detection was not possible is stored in a flag or the like (step S307), the peak search process is terminated, and the process returns to the flowchart shown in FIG. 4 which is the main routine.

  Hereinafter, operation control of the interchangeable lens 2 by the lens control unit 5 will be described with reference to flowcharts shown in FIGS. 7A and 7B.

  First, when the power of the camera body 1 (not shown) is turned on, the lens power is supplied from the camera body 1 side to the interchangeable lens 2 via the lens contact portion 8. By supplying lens power to the interchangeable lens 2, each part in the interchangeable lens 2 is initialized, and the lens control unit 5 can be operated. Then, the control unit 16 waits for a body / lens communication request (step S400). Here, when a body / lens communication request from the control unit 16 is generated, body / lens communication is performed and a command transmitted from the control unit 16 is received (step S401).

  Steps S402 to S404, which will be described later, are the types of commands received by the lens control unit 5 through body / lens communication (IAF lens drive command in step S402, MF mode command in step S403, and initial in step S404). A communication command). Step S405 is a step for performing a process for determining a command other than the above commands.

  First, it is determined whether an imager AF lens drive command, which is a lens drive command in the imager AF, has been received (step S402). If it is determined in step S402 that an imager AF lens driving command has been received, the lens driving unit 4 performs lens driving of the focus lens 3A based on the imager AF lens driving command (step S415). This step S415 is a step corresponding to step S204 (lens movement start) shown in FIG.

  After starting the lens driving in step S415, the control unit 16 waits for the falling edge of the signal VDP output from the control unit 16 to the lens control unit 5 via the lens contact unit 8 and synchronized with the vertical synchronization signal VD ( Step S416). Here, when the falling edge of the signal VDP is detected, output data of the lens position encoder 15 indicating the lens position of the focus lens 3A is acquired (step S417). Then, it waits for the rising edge of the signal VDP (step S418). Here, when the rising edge of the signal VDP is detected, the lens position of the focus lens 3A acquired in step S417 is transmitted to the control unit 16 (step S419).

  Thereafter, it is determined whether or not a lens stop command, which is a command for stopping the driving of the focus lens 3A, has been received (step S420). If it is determined in step S420 that a lens stop command has been received, the driving of the focus lens 3A is stopped by the lens driving unit 4 (step S421). Then, the process returns to step S400.

  On the other hand, if it is determined in step S420 that a lens stop command has not been received, the process returns to step S416. Thereafter, the above-described operation control is repeated until it is determined in step S420 that a lens stop command has been received. That is, while moving the focus lens 3A, the lens position of the focus lens 3A is acquired and stored by the count value of the output pulse of the lens position encoder 15 in synchronization with the fall of the signal VDP, and the rise of the signal VDP. The lens position of the focus lens 3 </ b> A acquired and stored in synchronization with is transmitted to the control unit 16.

  When step S402 is branched to NO, it is determined whether an MF mode command has been received (step S403). When this step S403 is branched to YES, it is detected from the output of the focus ring encoder 6 whether or not the focus ring 9 has been operated (step S406). When step S406 is branched to YES, the driving direction of the focus lens 3A corresponding to the rotation direction of the focus ring 9 is obtained by reading the output pulse of the focus ring encoder 6, and a predetermined data table is referred to. Alternatively, the driving amount of the focus lens 3A corresponding to the rotation amount and the rotation speed of the focus ring 9 is obtained based on a conversion formula or the like, and the focus lens 3A is moved to the lens driving unit 4 according to the driving direction and the driving amount. (Step S407).

  Then, it waits for the signal VDP to fall (step S409). In the fall waiting state in step S409, the lens driving operation of the focus lens 3A corresponding to the rotation of the focus ring 9 is continued (step S410). When the falling edge of the signal VDP is detected in the step S410, the position data of the focus lens 3A is obtained from the count value of the output pulse from the lens position encoder 15 indicating the lens position of the focus lens 3A (step S411).

  Thereafter, it waits for the rising edge of the vertical synchronizing signal VD from the image processing unit 13 (step S412). Note that, in the rise waiting state in step S412, the lens driving operation corresponding to the rotation of the focus ring 9 is continued (step S413). When the rising edge of the signal VDP is detected in step S412, position data indicating the lens position of the focus lens 3A acquired in step S411 is transmitted to the control unit 16 through body / lens communication (step S414). . Thereafter, the process returns to step S406, and the processing from step S406 to step S414 is repeatedly executed.

  When step S403 is branched to NO, it is determined whether an initial communication command has been received (step S404). When step S404 is branched to YES, body / lens initial communication is performed (step S424). In the body / lens initial communication, initial setting in the interchangeable lens 2 is performed based on communication with the control unit 16, and various data stored in the interchangeable lens 2 are stored in the control unit 16. Send to.

  Examples of various data stored in the interchangeable lens 2 include information on lens type, focal length, shootable distance, total number of focus pulses, motor type, various correction values related to AF, and the like. be able to. After the body / lens initial communication is completed in step S424, the process returns to step S400. On the other hand, when step S404 is branched to NO, a command determination process other than the IAF lens drive command, MF mode command, and initial communication command is performed (step S405).

  Therefore, when the interchangeable lens 2 is turned on, the body lens initial communication is performed in the step S424 through the processes of the step S400, the step S401, the step S402, the step S403, and the step S404. become.

  When step S406 is branched to NO, it is checked whether there is a communication request from the control unit 16 (step S408). When step S408 is branched to NO, the process proceeds to step S406. That is, when step S408 is branched to NO, the detection of the operation of the focus ring 9 in step S406 and the body communication request check in step S408 are repeatedly executed.

  On the other hand, when step S408 is branched to YES, body / lens communication is performed and a command is received from the control unit 16 (step S422). Then, it is determined whether or not the command received in step S422 is an MF mode end command (step S423). When step S423 is branched to YES, the MF mode is terminated and the process returns to step S400. When step S423 is branched to NO, the process returns to step S406. That is, only the MF mode end command is accepted during the MF mode. If the command received in step S422 is other than the MF mode end command, the command is ignored and the process returns to S406.

  Hereinafter, the timing of operation control in the imager AF will be described with reference to the timing chart shown in FIG.

  First, in step S <b> 110 of the flowchart shown in FIG. 4, the control unit 16 transmits an imager AF lens drive command to the lens control unit 5. Then, the lens control unit 5 receives the imager AF lens driving command, and starts the lens driving of the focus lens 3A by the lens driving unit 4 in step S204 of the flowchart shown in FIG.

  On the other hand, the lens position encoder 15 generates an encoder pulse signal as the focus lens 3A moves. Then, the lens control unit 5 acquires the lens position of the focus lens 3A by counting the encoder pulse signal.

  As can be seen from the timing chart shown in FIG. 8, the control unit 16 continues to drive the focus lens 3A. In the camera body 1, the image pickup operation of the image pickup device 7 is performed in accordance with a predetermined timing of the vertical synchronization signal VD generated by the image processing unit 13.

  When the exposure of the image sensor 7 (EXP in the image sensor 7 operation time chart shown in FIG. 8) is completed, the video signal in the image sensor 7 is read out by the image processing unit 13 (image sensor shown in FIG. 8). (READ in 7 operation time chart). In parallel with this readout operation, the focus detection unit 14 calculates an AF evaluation value (IAF) (step S301 in the flowchart shown in FIG. 6). Note that the end timing of calculation of the AF evaluation value is set in advance to end before the falling edge of the vertical synchronization signal VD.

  The lens control unit 5 waits for the signal VDP to fall (step S416 in the flowchart shown in FIG. 7A), and when it detects the fall of the signal VDP, the count value of the pulse output from the lens position encoder 15 Thus, the position data of the focus lens 3A is acquired (step S417 in the flowchart shown in FIG. 7A).

  Thereafter, the lens control unit 5 waits for the rise of the signal VDP (vertical synchronization signal VD) (step S418 in the flowchart shown in FIG. 7A), and when detecting the rise of the signal VDP, the focus lens acquired as described above. The lens position data of 3A is transmitted to the control unit 16 (step S419 in the flowchart shown in FIG. 7A).

  In other words, the control unit 16 waits for the rising edge of the vertical synchronizing signal VD (step S206 in the flowchart shown in FIG. 5), and detects the rising edge of the vertical synchronizing signal VD, and transmits the lens transmitted from the lens control unit 5. The position is received (step S207 in the flowchart shown in FIG. 5).

  As described above, the control unit 16 performs body-lens communication for transmitting the position data of the focus lens 3A in synchronization with the rise of the vertical synchronization signal VD, so that the vertical synchronization signal VD falls. The position data of the focus lens 3A is acquired.

  A series of operations from the exposure operation of the image sensor 7 to the transmission operation of the lens position data of the focus lens 3A to the control unit 16 by the lens control unit 5 is the focus lens during the imager AF operation. It is repeatedly executed during the driving of 3A.

  When the control unit 16 transmits a lens stop command to the lens control unit 5 through body / lens communication, the lens control unit 5 causes the lens driving unit 4 to stop driving the focus lens 3A (see FIG. 7A). Step S421) in the flowchart shown.

  FIG. 9 is a timing chart for explaining the peak search operation by the manual operation in step S106 shown in FIG.

  First, in step S105 shown in FIG. 4, an MF mode command is transmitted from the control unit 16 to the lens control unit 5. In step S106, the control unit 16 starts a peak search process. The time chart shown in FIG. 9 is a time chart from the start of the peak search process.

  When the user operates the focus ring 9, the focus ring encoder 6 outputs a focus ring encoder signal pulse. Based on the focus ring encoder signal pulse, the lens control unit 5 starts driving the focus lens 3A by the lens driving unit 4. The lens position encoder 15 generates an encoder pulse signal as the focus lens 3A moves. Then, by counting the encoder pulse signal, the lens control unit 5 acquires the lens position of the focus lens 3A.

  On the other hand, in the camera body 1, the image capturing operation of the image sensor 7 is performed by the control unit 16 in accordance with a predetermined timing of the vertical synchronization signal VD generated by the image processing unit 13. When the exposure of the image sensor 7 (EXP in the image sensor 7 operation time chart shown in FIG. 9) is completed, the video signal in the image sensor 7 is read out by the image processing unit 13 (operation of the image sensor 7 shown in FIG. 9). READ in the time chart). In parallel with this reading operation, the focus detection unit 14 calculates an AF evaluation value (step S301 in the flowchart shown in FIG. 6). Note that the end timing of calculation of the AF evaluation value is set in advance so as to end before the fall of the vertical synchronization signal VD.

  Here, the lens control unit 5 waits for the fall of the signal VDP (step S409 in the flowchart shown in FIG. 7A), and when detecting the fall of the signal VDP, counts the pulses output from the lens position encoder 15. The lens position of the focus lens 3A is acquired from the value (step S411 in the flowchart shown in FIG. 7A).

  Thereafter, the lens control unit 5 waits for the rise of the signal VDP (vertical synchronization signal VD) (step S412 in the flowchart shown in FIG. 7A), and when the rise of the signal VDP is detected, the focus lens acquired as described above. The lens position of 3A is transmitted to the control unit 16 (step S414 in the flowchart shown in FIG. 7A).

  The control unit 16 waits for the rising edge of the vertical synchronizing signal VD (step S302 in the flowchart shown in FIG. 6). When the rising edge of the vertical synchronizing signal VD is input, the control unit 16 transmits the above-mentioned signal transmitted from the lens control unit 5. The position data of the focus lens 3A is received (step S303 in the flowchart shown in FIG. 6).

  As described above, by performing body-lens communication regarding the lens position of the focus lens 3A in synchronization with the rise of the vertical synchronization signal VD, the control unit 16 performs the focus at the fall of the vertical synchronization signal VD. The lens position of the lens 3A can be acquired.

  A series of operations from transmission of the MF mode command to transmission operation of the lens position of the focus lens 3A to the control unit 16 by the lens control unit 5 is repeatedly executed during peak search.

  Then, when the control unit 16 transmits an MF mode end command to the lens control unit 5 through body / lens communication (the step S422 in the flowchart shown in FIG. 7A), the lens control unit 5 sends the lens drive unit 4 the command. The driving of the focus lens 3A is stopped (step S423 in the flowchart shown in FIG. 7A).

  Next, a graph showing an example of the correlation between the lens position of the focus lens 3A shown in FIG. 10A and the AF evaluation value (when a peak of the AF evaluation value occurs with the movement of the focus lens 3A). The operation of the peak search (the above step S106 in the flowchart shown in FIG. 4) will be described.

  As shown in FIG. 10A, the focus lens 3A is moved by the MF operation by the user, and the AF evaluation value changes with this movement. That is, in the example shown in FIG. 10A, in the vicinity of the peak of the AF evaluation value, the lens position of the focus lens 3A moves from P1 → P2 →... → P5. → H2 → ... → H5 When the focus lens 3A has a lens position P3, the AF evaluation value is H3, that is, a peak value.

  Note that the peak value is determined based on the following conditions, for example. That is, an AF evaluation value H3 (corresponding to the lens position P3) that satisfies the following expressions is determined to be a peak value.

H1, H2, H3, H4, H5> Hth (Formula 1)
H2> H1 and (H2-H1)> ΔHthl (Formula 2)
H3> H2 and (H3-H2)> ΔHth2 (Formula 3)
H3> H4 and (H3-H4)> ΔHth2 (Formula 4)
H4> H5 and (H4-H5)> ΔHth1 (Formula 5)
Here, (Equation 1) indicates that the AF evaluation value is larger than the threshold Hth in the AF evaluation value which is a peak value candidate and the AF evaluation values of a total of 5 points (see FIG. 10A) on each of the two sides. It is a value. Further, (Expression 2) to (Expression 5) indicate that there is a difference larger than a predetermined value (ΔHth1, ΔHth2) between the five AF evaluation values adjacent to each other. An AF evaluation value that satisfies the conditions of (Expression 1) to (Expression 5) is determined as a peak value.

  That is, each time a new AF evaluation value H (lens position P) is obtained by the MF operation, the peak value determination is performed to determine whether or not the AF evaluation value H is a peak value. As described above, in the first embodiment, the numerical values of the AF evaluation values H1 to H5 and the difference values between them are used as a scale indicating the reliability level of the peak search and as the setting parameter of the scan range in the imager AF. To do. For example, the higher the reliability (the larger the numerical value or the difference value), the narrower the scan range in the imager AF can be, and the focus adjustment time can be shortened.

  FIG. 10B shows the operation of the imager AF (step S110 in the flowchart shown in FIG. 4) executed following the peak search shown in FIG. 10A (the step S106 in the flowchart shown in FIG. 4). It is a graph to show.

  Here, as shown in FIG. 10B, the imager AF operation is started in a state where the focus lens 3A is located at the lens position P5 by the above-described peak search. Since the peak value has already been searched for as the AF evaluation value H3 (lens position P3) at this time, the AF evaluation value is acquired while moving the focus lens 3A around the lens position P3, and the AF evaluation is performed. A coordinate value ((P6, H6) (P7, H7) (P8, H8)) is obtained. Then, the focus lens 3A is moved to the focus target lens position Pm where the AF evaluation value is a peak value calculated from the AF evaluation coordinate value by interpolation or the like. In the first embodiment, the imager AF as described above is performed.

  As described above, according to the first embodiment, high-accuracy focus adjustment can be performed without applying stress to the user regardless of the optical characteristics of the interchangeable lens 2 to be used and the focus lens driving mechanism. A camera system and a digital camera can be provided.

  Specifically, whether or not the interchangeable lens 2 is suitable for the imager AF is recorded in advance on the interchangeable lens 2 as lens type data, and it is determined whether or not the mounted interchangeable lens 2 is suitable for the imager AF. To do. Here, when it is determined that the interchangeable lens 2 is suitable for the imager AF, focus adjustment is performed by the imager AF. On the other hand, when it is determined that the interchangeable lens 2 is not suitable for the imager AF, it automatically shifts to the MF mode and AF corresponding to the change in the lens position of the focus lens 3A accompanying the user's manual focus adjustment operation. The peak value of the evaluation value is detected, and then the automatic shift to the imager AF mode is performed to perform automatic focusing. Such control makes it possible to perform high-precision focus adjustment without applying stress to the user regardless of the optical characteristics of the interchangeable lens 2 and the focus adjustment mechanism.

[Second Embodiment]
Next, a camera system and a digital camera according to the second embodiment of the present invention will be described. Only contents different from the camera system and digital camera according to the first embodiment will be described.

  Hereinafter, operation control by the control unit 16 of the digital camera according to the second embodiment will be described with reference to a flowchart shown in FIG.

  First, when a power source (not shown) provided in the camera body 1 is turned on by the user, the control unit 16 in the camera body 1 performs body / lens initial communication (step S900). That is, in step S900, the control unit 16 reads out various data stored in the memory 5A in the interchangeable lens 2, and stores the data in a storage unit (not shown) in the control unit 16. It is a step.

  Data relating to the interchangeable lens 2 communicated in the body-lens initial communication includes the total number of focus pulses (hereinafter referred to as the total number of lens pulses) corresponding to the entire photographing distance range of the interchangeable lens 2, and the focus lens driving speed ( (Hereinafter, referred to as “lens speed”), focal length, shootable distance, focus lens drive motor type, interchangeable lens ID, lens position resolution, and other information such as various correction values related to AF and the like. In the second embodiment, the focus lens driving speed is regarded as the number of driving pulses per unit time.

  After the body / lens communication is finished in step S900, the user waits until the release button 12 (the 1RSW) is turned on by half-pressing the release button (step S901). When the 1RSW is turned on, the step S901 is branched to YES, and the lens data of the interchangeable lens 2 is determined based on the data acquired in the body / lens initial communication in the step S900 (step S900). S903). Specifically, in the lens data determination in step S903, determination is performed based on the data on the total number of lens pulses and the lens speed, and the determination result is stored in a flag or the like.

  By the way, when step S901 is branched to NO, the process proceeds to step S902. After the process in step S902 is completed, the process returns to step S901. Note that step S902 is a step for performing the same processing as step S102 in the flowchart shown in FIG.

  Thereafter, it is determined whether or not the total number of lens pulses is greater than a predetermined value A (step S904). When step S904 is branched to NO, the process proceeds to step S911 described later. On the other hand, when step S904 is branched to YES, it is determined whether or not the lens speed is smaller than a predetermined value V (step S905). When step S905 is branched to YES, the process proceeds to step S906, and the processes in steps S906 to S916 are performed thereafter. Here, steps S906 to S916 are steps for performing the same processes as those in steps S105 to S115 in the flowchart shown in FIG.

  When step S904 is branched to NO and when step S905 is branched to NO, the process proceeds to step S911. As described above, step S911 is a step for performing the same processing as step S110 in the flowchart shown in FIG.

  As described above, according to the second embodiment, it is possible to provide a camera system and a digital camera that have the same effects as those of the first embodiment.

  That is, in the second embodiment, when the total number of lens pulses is smaller than the predetermined value A and when the lens speed is larger than the predetermined value V, only the imager AF is executed. On the other hand, when the total number of lens pulses is larger than the predetermined value A and the lens speed is smaller than the predetermined value V, the lens position of the focus lens 3A is automatically changed to the MF mode and the user's manual focus adjustment operation is performed. After detecting the peak of the AF evaluation value corresponding to the change in the image, the imager AF is executed to perform automatic focus adjustment.

  Specifically, the total number of focus lens pulses corresponding to the amount of movement of the focus lens 3A over the entire photographing distance range and the focus lens moving speed are stored in advance in the interchangeable lens 2 as lens data, and the camera body 1 Whether the interchangeable lens 2 mounted on the lens is an interchangeable lens suitable for the imager AF is determined using the lens data as a parameter. If it is determined that the interchangeable lens 2 is not suitable for the imager AF, coarse adjustment of focus adjustment is performed by the MF operation by the user, and then focus adjustment is performed by performing fine adjustment by the imager AF. As a result, regardless of the optical characteristics of the interchangeable lens 2 and the focus adjustment mechanism, high-precision focus adjustment can be performed without giving stress to the user. Note that, when it is determined that the interchangeable lens 2 is suitable for the imager AF, the focus adjustment is performed by the imager AF. In this case as well, high-precision focus adjustment can be performed without applying stress to the user.

[Modification]
Instead of setting the total number of focus pulses corresponding to the entire photographing distance range of the interchangeable lens 2 and the lens speed corresponding to the moving speed of the focus lens 3A as parameters, the total number of lens pulses is determined by the lens speed. Of course, the divided value (total number of lens pulses / lens speed) may be set as a parameter. In this case, for example, a numerical value obtained by dividing the total number of lens pulses by the lens speed (lens pulse total number / lens speed) is compared with a predetermined value as a parameter, and if larger than the predetermined value, it is determined that the imager AF is not suitable.

  Here, the numerical value obtained by dividing the total number of lens pulses by the lens speed is a parameter proportional to the lens driving time, that is, the time required for focus adjustment. Therefore, the magnitude of the focus adjustment time can also be determined using a numerical value obtained by dividing the total number of lens pulses by the lens speed.

  Furthermore, data indicating the lens position resolution (focus lens moving distance / pulse) acquired by the control unit 16 in the body / lens initial communication (step S900 in the flowchart shown in FIG. 11) is used as a parameter. May be. For example, even if the camera system has a different lens position resolution for each interchangeable lens 2, it is possible to easily know the focus adjustment time by calculating (lens position resolution / total number of lens pulses / lens speed).

[Third Embodiment]
Next, a camera system and digital camera according to a third embodiment of the present invention will be described. Only contents different from the camera system and digital camera according to the first embodiment will be described.

  Hereinafter, the operation control by the control unit 16 of the digital camera according to the third embodiment will be described with reference to the flowchart shown in FIG.

  First, when a power source (not shown) provided in the camera body 1 is turned on by the user, the control unit 16 in the camera body 1 performs body / lens initial communication (step S500). That is, in step S500, the control unit 16 reads out various data stored in the memory 5A in the interchangeable lens 2, and stores the data in a storage unit (not shown) in the control unit 16. It is a step.

  The data relating to the interchangeable lens 2 communicated in the body / lens initial communication includes information such as the closest possible photographing distance corresponding to the entire photographing distance range of the interchangeable lens 2, the focal length, and the type of the focus lens driving motor. And various correction values related to AF and AF.

  After the body / lens communication is finished in step S500, the user waits until the release button 12 (the 1RSW) is turned on by half-pressing the release button (step S501). When the 1RSW is turned on, the step S501 is branched to YES, and the lens data of the interchangeable lens 2 is determined based on the data acquired in the body / lens initial communication in the step S500 (step S500). S503). Specifically, in the lens data determination in step S503, determination is performed based on the closest possible distance, the focal distance, and the type of the focus lens drive motor that can be photographed by the interchangeable lens 2, and the determination result is used as a flag or the like. Remember.

  By the way, when step S501 is branched to NO, the process proceeds to step S502, and after the process in step S502 is completed, the process returns to step S501. In step S502, for example, when the zoom type interchangeable lens 2 is used, the focal length value when the focal length changes due to zooming, the closest distance that changes with zooming, and the like. Is acquired through body / lens communication. Further, when the interchangeable lens 2 having a function capable of limiting the shootable distance range is used, the closest distance value when the closest distance is changed is acquired by body / lens communication.

  After determining the lens data in step S503, it is determined whether or not the type of drive source (the focus lens drive motor) included in the lens drive unit 4 is a stepping motor (step S504). Note that data for determining the type of drive source is set as shown in FIG. 13, for example. When step S504 is branched to NO, the process proceeds to step S512 described later. On the other hand, when step S504 is branched to YES, it is determined whether the focal length is a value smaller than the predetermined value f (step S505). When this step S505 is branched to YES, the process proceeds to step S512 described later. When step S505 is branched to NO, it is determined whether or not the closest distance is greater than a predetermined value L (step S506). When this step S506 is branched to YES, the process proceeds to step S512 described later.

  If step S506 is branched to NO, the process proceeds to step S507, and the processes in steps S507 to S517 are performed thereafter. Steps S507 to S517 are steps for performing the same processes as those in steps S105 to S115 in the flowchart shown in FIG.

  When step S504 is branched to YES, step S505 is branched to YES, and step S506 is branched to YES, the process proceeds to step S512. As described above, step S512 is a step for performing the same processing as step S110 in the flowchart shown in FIG.

  As described above, according to the third embodiment, it is possible to provide a camera system and a digital camera that have the same effects as those of the first embodiment.

  That is, in the third embodiment, when the interchangeable lens 2 uses a stepping motor as a drive source, only the imager AF is executed. Even when the interchangeable lens 2 uses a drive source other than the stepping motor (DC motor or the like) as a drive source, the closest distance is a value greater than the predetermined value L or the focal distance is a value smaller than the predetermined value f. If it is, only the imager AF is executed.

  On the other hand, the interchangeable lens 2 is a drive source other than a stepping motor (DC motor or the like), and the closest distance is a value smaller than a predetermined value L and the focal length is a value larger than a predetermined value f. In this case, the mode automatically shifts to the MF mode, and after detecting the peak of the AF evaluation value corresponding to the change in the lens position of the focus lens 3A accompanying the user's manual focus adjustment operation, the imager AF is executed. Perform auto focus adjustment.

  Specifically, the closest distance that can be photographed by the interchangeable lens 2, the focal length, and the type of the focus lens drive motor that is a drive source are stored in advance in the interchangeable lens 2 as lens data, and the camera Whether or not the interchangeable lens 2 attached to the body 1 is an interchangeable lens suitable for the imager AF is determined using the lens data as a parameter. If it is determined that the interchangeable lens 2 is not suitable for the imager AF, coarse adjustment of focus adjustment is performed by the MF operation by the user, and then focus adjustment is performed by performing fine adjustment by the imager AF. As a result, regardless of the optical characteristics of the interchangeable lens 2 and the focus adjustment mechanism, high-precision focus adjustment can be performed without giving stress to the user. Note that, when it is determined that the interchangeable lens 2 is suitable for the imager AF, the focus adjustment is performed by the imager AF. In this case as well, high-precision focus adjustment can be performed without applying stress to the user.

  The interchangeable lens 2 is a zoom type in which the focal length is variable, a type in which the closest distance changes according to zoom, or a function capable of changing the shootable distance range. Even in the case of the type having, the latest state of the interchangeable lens 2 is acquired by the body-lens communication in the step SS502, so that the focal length, the closest distance, etc. at the time are determined in the step S505 and the step S506. Always reflected.

[Modification]
Even if the imaging magnification is used instead of the closest distance as a parameter for determining whether or not the interchangeable lens 2 is an interchangeable lens suitable for imager AF, the camera system according to the third embodiment and The same effect as a digital camera can be obtained.

[Fourth Embodiment]
Next, a camera system and a digital camera according to a fourth embodiment of the present invention will be described. Only contents different from the camera system and digital camera according to the first embodiment will be described.

  FIG. 14 is a diagram showing a system configuration of a digital camera according to the fourth embodiment of the present invention. Here, the main difference in system configuration between the digital camera according to the fourth embodiment and the digital camera according to the first embodiment is that the accessory 20 is attached to the camera body 1 and the interchangeable lens 2. The presence / absence and presence / absence of the image display LCD panel 23 in the camera body 1. The camera system and digital camera according to the fourth embodiment have a semi-automatic focus adjustment mode (semi-manual mode) as an operation mode. The details of the semi-automatic focus adjustment mode will be described later.

  The accessory 20 is specifically a wide converter, a teleconverter, an intermediate ring (close-up ring), or the like, and is configured to be detachable from the camera body 1 and the interchangeable lens 2. The accessory 20 includes an optical system 19 corresponding to optical characteristics (however, the intermediate ring does not have an optical system) and an accessory control unit 17 that controls the entire accessory 20. The accessory control unit 17 communicates with the control unit 16 via the lens contact unit 8. The accessory control unit 17 communicates with the lens control unit 5 in the interchangeable lens 2 via the accessory contact unit 18.

  In the fourth embodiment, the camera body 1 has an image display LCD panel 23 with a built-in backlight in addition to the system configuration similar to that of the digital camera according to the first embodiment. Yes. The image display LCD panel 23 is provided on the back side of the camera body (the user side during shooting). Here, the display image formed by the image processing unit 13 is sent to the image display LCD panel 23 and displayed.

  The image display LCD panel 23 can display the AF evaluation value superimposed on the image for the purpose of assisting the MF operation in the MF mode.

  Hereinafter, operation control by the control unit 16 of the digital camera according to the fourth embodiment will be described with reference to the flowchart shown in FIG.

  First, when a power source (not shown) provided in the camera body 1 is turned on by a user, the control unit 16 in the camera body 1 is in the lens control unit 5 and the accessory 20 in the interchangeable lens 2. The body / lens initial communication is performed with the accessory control unit 17 (step S600). That is, in step S600, the control unit 16 stores various data stored in the memory 5A in the interchangeable lens 2 and various data stored in a memory (not shown) in the accessory 20. This is a step of reading and storing the data in a storage unit (not shown) in the control unit 16.

  The data relating to the interchangeable lens 2 communicated in step S600 includes the shootable distance, the focal length, and the focus lens drive corresponding to the entire photographing area of the interchangeable lens 2 corresponding to the entire photographing distance range of the interchangeable lens 2. Examples include information such as motor type and various correction values related to AF and the like. Further, the data related to the accessory 20 communicated in step S600 may include information such as the type of the accessory 20 (for example, a wide converter, a teleconverter, or an intermediate ring), conversion magnification, optical path length, and the like.

  After the body / lens communication is finished in step S600, the user waits until the release button 12 (the 1RSW) is turned on by half-pressing the release button (step S601). When the 1RSW is turned on, the step S601 is branched to YES, and the lens data of the interchangeable lens 2 is determined based on the data acquired in the body / lens initial communication in the step S600 (step S600). S603). Specifically, in the lens data determination in step S603, it is determined whether or not the accessory 20, that is, the teleconverter, the wide converter, the intermediate ring, or the like is attached to the camera body 1 and the interchangeable lens 2. The determination result is stored in a flag or the like.

  By the way, when step S601 is branched to NO, the process proceeds to step S602, and after the process in step S602 is completed, the process returns to step S601. In step S602, for example, when the zoom type interchangeable lens 2 is used, the focal length value when the focal length changes due to zooming, the closest distance that changes with zooming, and the like. Is acquired through body / lens communication. Further, when the interchangeable lens 2 having a function capable of limiting the shootable distance range is used, the closest distance value when the closest distance is changed is acquired by body / lens communication.

  After determining the lens data in step S603, it is determined whether or not a wide converter is attached to the camera body 1 and the interchangeable lens 2 (step S604). When this step S604 is branched to YES, the process proceeds to step S618 described later. When step S604 is branched to NO, it is determined whether an intermediate ring is attached to the camera body 1 and the interchangeable lens 2 (step S605). When step S605 is branched to NO, the process proceeds to step S618 described later. When step S605 is branched to YES, it is determined whether a teleconverter is attached to the camera body 1 and the interchangeable lens 2 (step S606). When this step S606 is branched to NO, the process proceeds to step S618 described later.

  If step S606 is branched to YES, the process proceeds to step S607, and the semi-manual mode processing in steps S607 to S617 is performed thereafter. This semi-manual mode is a mode in which MF and imager AF are used together.

  First, an MF mode setting command is transmitted to the lens control unit 5 in the interchangeable lens 2 (step S607). Subsequently, a peak search process for searching for the peak value of the AF evaluation value is performed (step S608). Details of the peak search processing in step S608 will be described later in detail with reference to the flowchart shown in FIG. If the release button that was half-pressed during the peak search process is released, the peak search process ends. Here, during the peak search, a so-called live view image (through image) is acquired at a period in which the vertical synchronization signal VD is generated along with the acquisition of the AF evaluation value, and the image processing unit 13 performs the operation on the live view image. The image is displayed on the image display LCD panel 23 by performing predetermined image processing. In this case, as shown in FIG. 16, the live view image and the AF area 102 are displayed on the display screen 100 in the image display LCD panel 23, and the magnitude of the AF evaluation value is displayed as a bar display 101. Is done. Further, a focus display 103 which is a display indicating whether or not the focus is achieved is also displayed. This in-focus display 103 is a display used in step S615, step S616, step S620, and step S621, which will be described later, the lighting display indicates in-focus, and the blinking display indicates in-focus. With such a device, the user can recognize the magnitude of the AF evaluation value from the bar display 101 or the like by observing the display screen 100 and know the degree of focus on a desired subject. Can do. That is, peak search by MF operation becomes easier. Of course, the above-described display described with reference to FIG. 16 may be performed not on the image display LCD panel 23 but on the LCD panel 10 for finder display.

  When the peak search process in step S608 is completed, it is determined whether or not the 1RSW is turned off (step S609). When step S609 is branched to YES, an MF mode end command, which is a command to end the MF mode, is transmitted to the lens control unit 5 in the interchangeable lens 2 (step S610). Then, the process returns to step S601. On the other hand, when step S609 is branched to NO, it is determined whether or not the peak of the AF evaluation value has been detected as a result of the peak search process in step S608 (step S611). When this step S611 is branched to NO, the process proceeds to step S615 described later.

  Even when the 1RSW is turned OFF during the peak search in the step S608, it is determined that the 1RSW is turned OFF by moving to the step S609, and the process moves to the step S610.

  On the other hand, when step S611 is branched to YES, the scan range of the imager AF is set. A scan range of the imager AF is set (step S612). Here, the scan range is set to ΔX before and after the position of the focus lens 3A obtained by the peak search in step S608 as the center position. This ΔX is a predetermined scanning range so that the focusing operation can be performed with sufficiently high accuracy and high speed by the imager AF, and is stored in the memory 5A in the interchangeable lens 2, and is controlled by the control unit 16. It is read and used. Note that ΔX is appropriately changed depending on parameters such as the focal length of the interchangeable lens 2, the position (distance) of the focus lens 3A, and the reliability of phase difference detection.

  After setting the scan range of the imager AF in step S612, the process of the imager AF2 (see the flowchart shown in FIG. 17) is executed (step S613). Note that the processing in the imager AF2 is processing in which the steps S200 to S202 are deleted from the processing of the imager AF described with reference to FIG. That is, Steps S700 to S712 in the imager AF2 are steps for performing the same processing as Steps S203 to S215 in the flowchart shown in FIG. Therefore, the description of the operation control of the imager AF2 is omitted.

  After finishing the processing of the imager AF2 in the step S613, it is determined with reference to a flag or the like whether or not the in-focus state is obtained by the processing of the imager AF2 (step S614). When step S614 is branched to YES, the in-focus display 103 indicating that the in-focus state is obtained is displayed on the image display LCD panel 23 (step S616). On the other hand, when step S614 is branched to NO, the image display LCD panel 23 is caused to blink on the image display LCD panel 23 to indicate that the in-focus state 103 is out of focus (step S615). The above steps S607 to S616 are the processes in the semi-manual mode.

  By the way, when step S604 is branched to YES, step S605 is branched to NO, and step S606 is branched to NO, the scan range of the focus lens 3A in the imager AF is set as the focus lens movable range. The entire area, that is, the distance from the closest distance to infinity is set (step S618). Then, the process of the imager AF2 is executed (step S619).

  After finishing the processing of the imager AF2 in the step S619, it is determined by referring to a flag or the like whether or not the in-focus state is obtained by the processing of the imager AF2 (step S620). When step S620 is branched to YES, the in-focus display 103 indicating that the in-focus state is obtained is displayed on the image display LCD panel 23 (step S622). On the other hand, when step S620 is branched to NO, the image display LCD panel 23 is caused to blink on the image display LCD panel 23 to indicate that the in-focus state is out of focus (step S621).

  After the in-focus display is performed in step S616 or step S622, or after the out-of-focus display is performed in step S615 or step S621, a shooting instruction such as pressing the release button fully is given by the user. Based on this shooting instruction, shooting is performed according to a normal shooting sequence (step S617). After the photographing is completed, the process returns to step S601 and waits for the release switch 12 (1RSW) to be turned on.

  As described above, according to the fourth embodiment, it is possible to provide a camera system and a digital camera that have the same effects as those of the first embodiment.

  That is, in the fourth embodiment, when a wide converter is attached as the accessory 20, only the imager AF is executed. This is because the focal length of the interchangeable lens 2 is converted to a shorter focal length by the wide converter, so that the depth of field becomes deep without changing the focus adjustment time, and the focus adjustment accuracy is higher. It is a measure in view of changing.

  When the teleconverter is attached as the accessory 20 and the intermediate ring is attached, the focus adjustment is roughly adjusted by the MF operation by the user, and then the focus adjustment is finely adjusted by the imager AF. Do. This is because the focal length of the photographic optical system is converted to the long focal length side by mounting the teleconverter, so that the change in the AF evaluation value (contrast) with respect to the change in the predetermined defocus amount is reduced, which is disadvantageous for the imager AF. It is a measure that takes into account that it becomes a necessary condition. In addition, since the shootable distance is shifted to the near distance side by attaching an intermediate ring (close-up ring), macro shooting with a large defocus amount is achieved, and the AF evaluation value (contrast) changes less, which is disadvantageous for the imager AF. This is a measure in view of the conditions.

  Specifically, whether or not the camera body 1 and the interchangeable lens 2 are equipped with accessories 20 such as a wide converter, an intermediate ring, and a teleconverter is set as a parameter to determine whether or not the camera body 1 and the interchangeable lens 2 are suitable for the imager AF. judge. When it is determined that the state is not suitable for the imager AF, the focus adjustment is performed by performing a rough adjustment of the focus adjustment by the MF operation by the user, and then performing the fine adjustment by the imager AF. Thus, regardless of the attached accessory 20, it is possible to perform focus adjustment with high accuracy without giving stress to the user. Note that, when it is determined that the state is suitable for the imager AF, focus adjustment is performed by the imager AF. In this case as well, high-precision focus adjustment is possible without applying stress to the user.

  Note that the selection of the focus adjustment method varies greatly depending on the types and characteristics of the interchangeable lens 2 and the accessory 20, and various modifications other than those described above are possible. For example, the selection method of the focus adjustment method may be changed based on the closest distance of the interchangeable lens 2 or the combination of the focal length and the accessory type.

  In the fourth embodiment, the AF evaluation value is displayed together with the live view display of the image on the image display LCD panel 23 during the peak search operation. This display functions effectively as an aid to the MF operation by the user. The AF evaluation value displayed on the image display LCD panel 23 is not limited to the absolute value of the AF evaluation value, and may be a value obtained by performing predetermined processing on the AF evaluation value. For example, in view of the very large dynamic range of the AF evaluation value, a value obtained by appropriately compressing the AF evaluation value may be used for display, or a predetermined offset value is added depending on the subject situation. The values obtained may be used for display. The display form is not limited to the bar display as shown in FIG. 16, and numerical values may be displayed. The relationship between the lens position and the AF evaluation value is shown in a graph (for example, as shown in FIGS. 10A and 10B). A simple graph).

  As mentioned above, although this invention was demonstrated based on 1st Embodiment thru | or 4th Embodiment, this invention is not limited to embodiment mentioned above, A various deformation | transformation and application are within the range of the summary of this invention. Of course it is possible.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

1 is a diagram showing a system configuration of a digital camera according to a first embodiment of the present invention. The figure which shows the structure of a focus detection part. The graph which shows the relationship between the lens position of a focus lens, and AF evaluation value. 3 is a flowchart showing operation control by a control unit of the digital camera according to the first embodiment of the present invention. 6 is a flowchart showing operation control of the imager AF by the control unit of the digital camera according to the first embodiment of the present invention. 5 is a flowchart showing operation control of peak search processing by the control unit of the digital camera according to the first embodiment of the present invention. The 1st part of the flowchart which shows the operation control performed by the lens control part of an interchangeable lens in 1st Embodiment of this invention. The 2nd part of the flowchart which shows the operation control performed by the lens control part of an interchangeable lens in 1st Embodiment of this invention. 3 is a timing chart showing operation control timing in the imager AF of the digital camera according to the first embodiment of the present invention. 3 is a timing chart showing an operation of peak search by manual operation of the digital camera according to the first embodiment of the present invention. (A) is a graph showing an example of the correlation between the lens position of the focus lens and the AF evaluation value. (B) is a graph showing the operation of the imager AF executed following the peak search operation shown in (A). 9 is a flowchart showing operation control by a control unit of a digital camera according to a second embodiment of the present invention. The flowchart which shows the operation control by the control part of the digital camera which concerns on 3rd Embodiment of this invention. The figure which shows the classification table of the kind of drive source contained in a lens drive part. The figure which shows the system configuration | structure of the digital camera which concerns on 4th Embodiment of this invention. The flowchart which shows the operation control by the control part of the digital camera which concerns on 4th Embodiment of this invention. The figure which shows the display of the LCD panel for image displays. 10 is a flowchart showing operation control of an imager AF by a control unit of a digital camera according to a fourth embodiment of the present invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Camera body, 2 ... Interchangeable lens, 3 ... Shooting lens system, 3A ... Focus lens, 4 ... Lens drive part, 5 ... Lens control part, 6 ... Focus ring encoder, 7 ... Imaging element, 8 ... Lens contact part, DESCRIPTION OF SYMBOLS 9 ... Focus ring, 10 ... LCD panel, 11 ... Finder optical system, 12 ... Release switch, 13 ... Image processing part, 14 ... Focus detection part, 15 ... Lens position encoder, 16 ... Control part, 17 ... Accessory control part, DESCRIPTION OF SYMBOLS 18 ... Accessory contact part, 19 ... Optical system, 20 ... Accessory, 23 ... LCD panel, 100 ... Display screen, 101 ... Bar display, 102 ... AF area, 103 ... Focus display, 131 ... HPF, 132 ... A / D Converter 133: Focus detection area selection gate 134: Adder

Claims (25)

A camera system comprising a camera and a lens unit that can be attached to and detached from the camera,
The lens unit
Storage means for storing information relating to the characteristics of the lens unit;
A focus lens to adjust the focus position;
Lens control means for moving the focus lens to change the in-focus position of the lens unit in accordance with a movement operation of the focus lens by a photographer or based on an instruction signal from the camera;
Have
The above camera
A focus evaluation value calculating means for detecting a contrast of a subject image and calculating a focus evaluation value representing a degree of focus;
Based on the in-focus evaluation value, an auto-focus means that generates an instruction signal for controlling the focus lens to automatically move to the in-focus position and transmits the instruction signal to the lens control means;
Mode setting means for setting the focus lens focus adjustment by the auto focus means, or the focus lens focus adjustment by manual movement mode by the photographer moving the focus lens; ,
In a change of the focus evaluation value according to the movement of the focus lens, a peak detection means for detecting that the focus evaluation value has made a peak;
Determination means for determining whether or not the lens unit is suitable for focusing control by the auto-focus means based on information on the characteristics of the lens unit stored in the storage means;
Have
The mode setting means sets the manual focus mode when the determination means determines that the lens unit is not suitable for focus control by the automatic focus means, and further sets the peak detection means in the manual focus mode. When the peak of the focus evaluation value is detected by the camera system, the camera system is set to the autofocus mode. The lens unit further includes focus lens position detection means for detecting the position of the focus lens,
The peak detection means detects that the focus evaluation value has peaked from the output of the focus lens position detection means and the output of the focus evaluation value calculation means. The camera system described.   When the determination unit determines that the lens unit is not suitable for control by the automatic focus unit, the mode setting unit performs focus adjustment of the focus lens in the manual focus mode, and then performs the auto focus. The camera system according to claim 1, wherein the camera system is set to a semi-automatic focus mode, which is a mode for performing focus control in the mode.   The mode setting means sets the auto focus mode when the peak of the focus evaluation value is detected by the peak detection means in the manual focus mode in the semi-auto focus mode. 3. The camera system according to 3.   3. The camera system according to claim 2, wherein the information related to the characteristics of the lens unit stored in the storage means is information related to a moving speed of the focus lens.   3. The camera system according to claim 2, wherein the information relating to the characteristics of the lens unit stored in the storage means is information relating to a movement amount of the focus lens from the closest position to an infinite position.   3. The camera system according to claim 2, wherein the information relating to the characteristics of the lens unit stored in the storage means is information relating to the closest shooting distance of the lens unit.   3. The camera system according to claim 2, wherein the information on the characteristics of the lens unit stored in the storage means is information on the focal length of the lens unit. The lens unit includes a drive source for moving the focus lens,
3. The camera system according to claim 2, wherein the determination unit determines whether or not the lens unit is suitable for focusing control by the automatic focusing unit based on a type of the driving source.   The camera system according to claim 2, further comprising display means for displaying the focus evaluation value in the manual focus mode.   4. The camera system according to claim 3, wherein the camera further includes display means for displaying the focus evaluation value in the manual focus mode and the semi-automatic focus adjustment mode. The lens unit can be equipped with accessories that change the focal length,
The determination means determines whether or not the lens unit with the accessory attached is suitable for control by the auto-focus means based on the type of the accessory attached to the lens unit. The camera system according to claim 2. A digital camera in which a lens unit having a focus lens for adjusting a focal position is removable,
A focus evaluation value calculating means for detecting a contrast of a subject image and calculating a focus evaluation value representing a degree of focus;
Based on the focus evaluation value, automatic focus means for generating an instruction signal for controlling the focus lens to automatically move to a focus position and transmitting the instruction signal to the lens unit;
A mode setting means for setting the focus adjustment of the focus lens to the auto focus mode in which the auto focus means is executed or the manual focus mode in which the focus adjustment of the focus lens is executed by an operation of moving the focus lens by a photographer;
Determination means for determining whether or not the lens unit is suitable for focus control by the automatic focus means;
Comprising
The mode setting means sets the manual focus mode when the determination unit determines that the lens unit is not suitable for focus control by the autofocus means, and performs focus control by the autofocus means. A digital camera characterized in that the autofocus mode is set when it is determined to be suitable. A digital camera in which a lens unit having a focus lens for adjusting a focal position is removable,
A focus evaluation value calculating means for detecting a contrast of a subject image and calculating a focus evaluation value representing a degree of focus;
Based on the focus evaluation value, automatic focus means for generating an instruction signal for controlling the focus lens to automatically move to a focus position and transmitting the instruction signal to the lens unit;
Mode setting means for setting the focus lens focus adjustment by the auto focus means, or the focus lens focus adjustment by manual movement mode by the photographer moving the focus lens; ,
In a change of the focus evaluation value according to the movement of the focus lens, a peak detection means for detecting that the focus evaluation value has made a peak;
Determination means for determining whether or not the lens unit is suitable for focusing control by the automatic focusing means, based on information on the characteristics of the lens unit sent from the lens unit;
Comprising
The mode setting unit sets the manual focus mode when the determination unit determines that the lens unit is not suitable for focusing control by the automatic focus unit, and further detects the peak in the manual focus mode. A digital camera characterized in that when the peak of the focus evaluation value is detected by the means, the auto focus mode is set.   The peak detection means detects that the focus evaluation value has peaked from information on the position of the focus lens sent from the lens unit and the output of the focus evaluation value calculation means. The digital camera according to claim 14.   When the determination unit determines that the lens unit is not suitable for control by the automatic focus unit, the mode setting unit performs focus adjustment of the focus lens in the manual focus mode, and then performs the auto focus. 15. The digital camera according to claim 14, wherein the digital camera is set to a semi-automatic focus mode, which is a mode for performing focus control in the mode.   In the semi-automatic focus mode, when the peak of the focus evaluation value is detected by the peak detection unit in the manual focus mode, the focus control of the focus lens is continued by shifting to the autofocus mode. The digital camera according to claim 16.   16. The digital camera according to claim 15, wherein the information about the characteristics of the lens unit sent from the lens unit is information about the moving speed of the focus lens.   16. The digital camera according to claim 15, wherein the information on the characteristics of the lens unit sent from the lens unit is information on the amount of movement of the focus lens from the closest position to the infinity position. .   16. The digital camera according to claim 15, wherein the information on the characteristics of the lens unit sent from the lens unit is information on the closest shooting distance of the lens unit.   16. The digital camera according to claim 15, wherein the information on the characteristics of the lens unit sent from the lens unit is information on the focal length of the lens unit.   16. The information on the characteristics of the lens unit sent from the lens unit is information on the type of drive source for moving the focus lens included in the lens unit. Digital camera. It further comprises display means for displaying the focus evaluation value,
16. The digital camera according to claim 15, wherein, in the manual focus mode, the display means displays the focus evaluation value. It further comprises display means for displaying the focus evaluation value,
The digital camera according to claim 16, wherein the display means displays the focus evaluation value in the manual focus mode and the semi-automatic focus adjustment mode.   When the accessory is attached to the lens unit, the determination unit determines whether the accessory is suitable for control by the autofocus unit based on the type of the accessory. The camera system according to claim 15.

Images