Imaging device and lens device

Abstract

To provide a lens interchangeable imaging system capable of easily performing pan-focus imaging in a situation intended by a user.SOLUTION: A lens device 100 having a focus lens 105 is detachably attached to an imaging device 200. The imaging device includes an imaging element 201, and camera control means 206 for communicating with the lens device and causing the lens device to drive the focus lens. The camera control means receives first information about focal distance about the lens device from the lens device, acquires hyperfocal distance of the lens device using the first information, and transmits, to the lens device, second information for driving the focus lens to a lens position corresponding to the hyperfocal distance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an interchangeable-lens imaging device and a lens device.

Background Art

[0002] As one of imaging methods, there is pan-focus imaging in which the depth of field is increased and imaging is performed with focusing from a short distance to infinity. The user can calculate the hyperfocal distance from the nominal focal length of the lens, the number of pixels of the imaging element, and the set aperture value, and perform pan-focus setting by manually moving the focus lens to the lens position corresponding to the hyperfocal distance. However, such pan-focus setting requires specialized knowledge and skills of the user.

[0003] Patent Document 1 discloses an integrated-lens imaging device that automatically performs pan-focus imaging as a countermeasure when autofocus (AF) fails and the subject cannot be focused by AF. Patent Document 2 discloses an integrated-lens imaging device that can select a normal imaging mode for performing AF and a quick-shot mode for performing pan-focus imaging.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The lens-integrated imaging devices disclosed in Patent Documents 1 and 2 can automatically perform pan-focus setting when performing pan-focus imaging. However, Patent Documents 1 and 2 do not disclose automatic pan-focus setting in a lens-exchangeable imaging system in which various types of lenses can be attached to the imaging device.

[0006] The present invention provides an imaging device and a lens device that enable easy pan-focus imaging in a situation intended by a user in a lens-exchangeable imaging system.

Means for Solving the Problems

[0007] An imaging device according to one aspect of the present invention has a lens device having a focus lens detachably attached thereto. The imaging device includes an imaging element and camera control means for communicating with the lens device to drive the focus lens of the lens device. The camera control means receives first information regarding the focal length of the lens device transmitted from the lens device, obtains the over-focus distance of the lens device using the first information, Including information on the overfocus distance or information on the position of the focus lens according to the overfocus distance and is characterized by transmitting second information to the lens device. Note that a lens device detachably attached to the imaging device, which transmits first information to the imaging device, receives second information transmitted from the imaging device, and drives a focus lens to a position according to the overfocus distance based on the second information, is also one aspect of the present invention.

[0011] A control method according to another aspect of the present invention is applied to an imaging device having an imaging element, in which a lens device having a focus lens is detachably and communicably attached. The control method includes steps of receiving first information regarding the focal length of the lens device transmitted from the lens device, obtaining the over-focus distance of the lens device using the first information, Including information on the overfocus distance or information on the position of the focus lens according to the overfocus distance and transmitting second information to the lens device. Note that a control method for a lens device detachably and communicably attached to an imaging device controlled by the above control method, the control method having a step of transmitting first information to the imaging device and a step of driving a focus lens to a position according to the overfocus distance based on second information transmitted from the imaging device, is also another aspect of the present invention. Also, a program for causing the imaging device and the lens device to execute processing according to the above control method is also another aspect of the present invention.

Effects of the Invention

[0015] According to the present invention, in a lens-exchangeable imaging system, it becomes possible to easily perform pan-focus imaging in a situation intended by a user.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0018] FIG. 1 shows the configuration of the lens exchangeable imaging system which is an embodiment of the present invention. The imaging system is composed of a camera body 200 as an imaging device and an interchangeable lens 100 as a lens device detachably and communicably attached to the camera body 200.

[0019] The interchangeable lens 100 is mechanically and electrically connected to the camera body 200 via a mount (not shown). The interchangeable lens 100 has an imaging lens as an imaging optical system and a lens microcomputer (hereinafter referred to as a lens microcomputer) 111, and operates by receiving power supply from the camera body 200 via a power supply terminal (not shown) provided on the mount.

[0020] The camera body 200 has an imaging element 201 including phase difference focus detection pixels and the like, a signal processing circuit 202, a recording processing unit 203, a display unit 204, an operation unit 205, and a camera microcomputer (hereinafter referred to as a camera microcomputer) 206.

[0021] The imaging device 201 photoelectrically converts (images) the subject image formed by the imaging lens and outputs an analog imaging signal as an electrical signal. The analog imaging signal is converted into a digital imaging signal by an A / D conversion circuit (not shown).

[0022] The signal processing circuit 202 generates a video signal (captured image) by performing various image processes on the digital imaging signal. Also, the signal processing circuit 202 generates focus information indicating the contrast state of the subject image, that is, the focus state of the imaging lens, and luminance information representing the exposure state from the video signal.

[0023] The display unit 204 is a rear monitor or an electronic viewfinder, and displays a live view video corresponding to the video signal from the signal processing circuit 202 for the user to confirm the subject and composition. The recording processing unit 203 stores the video signal from the signal processing circuit 202 as still image data or moving image data in a recording medium (not shown).

[0024] The camera microcomputer 206 as camera control means controls the camera body 200 in response to inputs such as an imaging instruction switch and various setting switches included in the operation unit 205. The operation unit 205 also includes a switch (pan focus setting switch) for instructing the pan focus setting described later. The pan focus setting switch may be a dedicated switch, or a switch with assignable functions to which the user assigns the function as a pan focus setting switch by a custom function.

[0025] Also, the camera microcomputer 206 communicates with the lens microcomputer 111 via a communication terminal provided on the mount. Specifically, the camera microcomputer 206 transmits an aperture control command according to the luminance information and a focus control command according to the focus information generated from the output of the phase difference detection pixels of the imaging device 201 to the lens microcomputer 111. Also, the lens microcomputer 111 transmits information used for pan focus control described later to the camera microcomputer 206.

[0026] The imaging lens included in the interchangeable lens 100 includes a field lens 101, a zoom lens 102, an aperture unit 103, an anti-vibration lens 104, and a focus lens 105. The interchangeable lens 100 has a zoom operation ring (not shown), a focus operation ring 110, and the lens microcomputer 111 described above.

[0027] In response to a transmission request sent from the camera body 200 (camera microcomputer 206), the lens microcomputer 111 transmits lens data including identification information and optical information of the interchangeable lens 100 to the camera body 200. Also, in response to a reception request sent from the camera body 200, the lens microcomputer 111 receives camera data including various information of the camera body 200 from the camera body 200.

[0028] In response to an aperture control command received from the camera body 200, the lens microcomputer 111 drives the aperture unit 103 to open and close by driving the aperture control unit 107. The position of the aperture blades of the aperture unit 103 is detected by a sensor such as a Hall element, and the aperture position data is output to the lens microcomputer 111. The aperture control unit 107 that has received a drive command from the lens microcomputer 111 drives an aperture actuator composed of a stepping motor, a voice coil motor, or the like to drive the aperture blades to open and close. Thereby, the aperture unit 103 adjusts the amount of light.

[0029] In addition, in response to the focus control command received from the camera body 200, the lens microcomputer 111 drives the focus lens 105 in the optical axis direction by the focus control unit 109. The position of the focus lens 105 is detected using a sensor such as a photointerrupter, and the focus position data is output to the lens microcomputer 111. The lens microcomputer 111 calculates the target position of the focus lens 105 based on the focus position data and the focus drive amount data included in the focus control command. The focus control unit 109 that has received the drive command including the target position from the lens microcomputer 111 drives a focus actuator such as a stepping motor to move the focus lens 105. Thereby, autofocus (AF) is performed. The lens microcomputer 111 and the focus control unit 109 constitute lens control means.

[0030] Note that the lens microcomputer 111 can also move the focus lens 105 by the focus control unit 109 according to the operation amount of the focus operation ring 110. Thereby, manual focus (MF) becomes possible.

[0031] The zoom lens 102 is driven in the optical axis direction via a drive mechanism (not shown) when the zoom operation ring is operated by the user. Thereby, zooming in which the focal length of the imaging lens is changed is performed. The zoom position detection unit 106 detects the position (zoom position) of the zoom lens 102 using a sensor such as a variable resistor, and outputs the zoom position data to the lens microcomputer 111. The lens microcomputer 111 generates information regarding the focal length using the zoom position data.

[0032] The anti-shake lens 104 reduces (corrects) image blur caused by camera shake or the like by moving (shifting) in a direction orthogonal to the optical axis of the imaging lens. The anti-shake control unit 108 that has received the anti-shake command from the lens microcomputer 111 drives an anti-shake actuator constituted by a voice coil motor or the like according to the shake detected by a shake sensor such as a vibration gyro (not shown), and shifts the anti-shake lens 104. Thereby, optical anti-shake is performed.

[0033] Next, the pan focus control in this embodiment will be described. The camera microcomputer 206 starts the pan focus control by detecting the operation of the operation unit 205 (pan focus setting switch) by the user. For example, the camera microcomputer 206 calculates the overfocus distance using the focal length of the imaging lens received from the lens microcomputer 111, and transmits a pan focus drive command to the lens microcomputer 111 together with the overfocus distance.

[0034] The overfocus distance is the closest distance at which infinity is included in the depth of field, and can be obtained by the following formula (1). h = f 2 / (Fδ) (1) h: Overfocus distance [mm] F: Aperture value (F-number) f: Focal length of the imaging lens [mm] δ: Allowable confusion circle diameter [mm] Also, for example, the lens microcomputer 111 obtains the position of the focus lens 105 (hereinafter referred to as the pan focus position) at which the imaging lens is in the pan focus state as the lens position corresponding to the received overfocus distance. Then, the driving amount from the current position of the focus lens 105 to the pan focus position is calculated. Further, the lens microcomputer 111 drives the focus lens 105 by the calculated driving amount in the focus control unit 109. Thereby, the setting of the pan focus state (pan focus setting) is automatically performed. Hereinafter, specific processes for pan focus control will be described in Examples 1 to 4.

Embodiment

[0035] The flowchart of FIG. 2 shows the processes executed by the camera microcomputer 206 and the lens microcomputer 111 for the pan focus control in the first embodiment. The camera microcomputer 206 and the lens microcomputer 111 each execute this process according to a computer program. The process starting from Step 101 shows the process executed by the camera microcomputer 206, and the process starting from Step 201 shows the process executed by the lens microcomputer 111. The arrow between the two flowcharts indicates the communication direction of information.

[0036] The camera microcomputer 206 that starts the process in Step 101 receives information (first information) regarding the focal length of the current imaging lens from the lens microcomputer 111 in Step 102. Information regarding the focal length will be described later. Note that since the focal length of the imaging lens changes according to the operation of the zoom operation ring by the user, it is desirable to perform polling at a short period. If polling cannot be performed at a sufficiently short period, the order of Step 102 and Step 103 described later may be swapped.

[0037] In Step 103, the camera microcomputer 206 waits for the operation of the pan focus setting switch by the user. If the operation is not detected, it returns to Step 102, and if the operation is detected, it proceeds to Step 104.

[0038] In Step 104, the camera microcomputer 206 calculates (acquires) the over-focus distance using Equation (1) with the focal length obtained from the information received from the lens microcomputer 111 in Step 102, the aperture value set in the pan focus imaging, and the allowable confusion circle diameter. Note that data of the over-focus distance calculated in advance with combinations of different focal lengths, aperture values, and allowable confusion circle diameters may be stored as table data, and the corresponding over-focus distance may be read out (acquired) therefrom.

[0039] Next, in Step 105, the camera microcomputer 206 transmits the information regarding the obtained overfocus distance to the lens microcomputer 111. The information regarding the overfocus distance (second information) may be information indicating the overfocus distance itself, or may be information convertible to the overfocus distance in the lens microcomputer 111, such as parameters (variables) of a function indicating the overfocus distance.

[0040] Next, in Step 106, the camera microcomputer 206 transmits a pan focus drive command to the lens microcomputer 111. Then, the camera microcomputer 206 ends the process in Step 107.

[0041] On the other hand, the lens microcomputer 111 that started the process in Step 201 obtains the focal length of the current imaging lens from the zoom position data obtained from the zoom position detection unit 106 in Step 202, and transmits information regarding the focal length to the camera microcomputer 206. The information regarding the focal length may be information indicating the focal length itself, or may be information convertible to the focal length in the camera microcomputer 206, such as the zoom position.

[0042] Next, in Step 203, the lens microcomputer 111 receives the information regarding the overfocus distance from the camera microcomputer 206. Further, in Step 204, the lens microcomputer 111 receives a pan focus drive command from the camera microcomputer 206.

[0043] Next, in Step 205, the lens microcomputer 111 converts the overfocus distance obtained from the information received in Step 203 into a pan focus position, and calculates the difference (drive amount) from the current position of the focus lens 105 to the pan focus position.

[0044] Next, in Step 206, the lens microcomputer 111 drives the focus lens 105 by the drive amount calculated in Step 205 by the focus control unit 109 to obtain a pan focus state. Then, the lens microcomputer 111 ends the process in Step 207.

[0045] According to this embodiment, panoramic focus imaging can be easily performed at the situation (any timing) intended by the user.

Embodiment

[0046] Next, Embodiment 2 will be described. In Embodiment 1 described above, the case where the lens microcomputer 111 calculates (converts) the panoramic focus position using the information on the overfocus distance acquired by the camera microcomputer 206 and calculates the driving amount of the focus lens 105 was described. In contrast, in this embodiment, the camera microcomputer 206 acquires the overfocus distance and converts it to the panoramic focus position, and transmits information (second information) on the panoramic focus position to the lens microcomputer 111.

[0047] The flowchart of FIG. 3 shows the processes executed by the camera microcomputer 206 and the lens microcomputer 111 for panoramic focus control in Embodiment 2. The process starting from Step 301 shows the process executed by the camera microcomputer 206, and the process starting from Step 401 shows the process executed by the lens microcomputer 111.

[0048] The camera microcomputer 206 that starts processing in Step 301 receives information on the focal length of the current imaging lens from the lens microcomputer 111 in Step 302. Also, in Step 303, the camera microcomputer 206 receives information (third information) on the conversion coefficient used to convert the focal length obtained from the information received in Step 302 to the position of the focus lens 105 from the lens microcomputer 111. Information on the conversion coefficient will be described later.

[0049] Note that since the focal length of the imaging lens and the conversion coefficient change depending on the operation of the zoom operation ring by the user, it is desirable to perform polling at a short cycle. Also, it is desirable that the focal length and the conversion coefficient are acquired at the same position of the zoom lens 102. For this reason, it is desirable to perform the processes of Step 302 and Step 303 within as short a time as possible or simultaneously (in parallel).

[0050] In Step 304, the camera microcomputer 206 waits for the user to operate the pan focus setting switch. If the operation is not detected, it returns to Step 302. If the operation is detected, it proceeds to Step 305.

[0051] In Step 305, the camera microcomputer 206 uses the focal length obtained from the information received from the lens microcomputer 111 in Step 302, the aperture value set in the pan focus imaging, and the allowable confusion circle diameter to obtain the over-focus distance according to Equation (1) or from the table data described in the first embodiment. Further, the camera microcomputer 206 converts the obtained over-focus distance to the pan focus position using the conversion coefficient obtained from the received information in Step 303. Then, in Step 306, the camera microcomputer 206 transmits information regarding the pan focus position to the lens microcomputer 111. The information regarding the pan focus position may be information indicating the position of the focus lens 105 itself, or may be information that can be converted to the position of the focus lens 105 in the lens microcomputer 111.

[0052] Subsequently, in Step 307, the camera microcomputer 206 transmits a pan focus drive command to the lens microcomputer 111. Then, the camera microcomputer 206 ends the process in Step 308.

[0053] On the other hand, the lens microcomputer 111 that started the process in Step 401 obtains the focal length of the current imaging lens from the zoom position data obtained from the zoom position detection unit 106 in Step 402, and transmits information regarding the focal length to the camera microcomputer 206.

[0054] Next, in Step 403, the lens microcomputer 111 transmits information regarding the above-described conversion coefficient to the camera microcomputer 206. The information regarding the conversion coefficient may be information indicating the conversion coefficient itself, similar to the information regarding the focal length, or may be information that can be converted to the conversion coefficient in the camera microcomputer 206.

[0055] Next, in Step 404, the lens microcomputer 111 receives information regarding the pan focus position from the camera microcomputer 206. Further, in Step 405, the lens microcomputer 111 receives a pan focus drive command from the camera microcomputer 206.

[0056] Next, in Step 406, the lens microcomputer 111 calculates the driving amount from the current position of the focus lens 109 to the pan focus position obtained from the information received in Step 404.

[0057] Then, in Step 407, the lens microcomputer 111 drives the focus lens 105 by the driving amount calculated in Step 406 by the focus control unit 109 to obtain a pan focus state. Then, the lens microcomputer 111 ends the process in Step 408.

[0058] In this embodiment, the conversion from the calculation of the overfocus distance to the pan focus position is performed by the camera microcomputer 206. Therefore, even when the processing ability of the lens microcomputer 111 is low, pan focus imaging can be easily performed at the situation (arbitrary timing) intended by the user.

Embodiment

[0059] Next, Embodiment 3 will be described. In this embodiment, the lens microcomputer 111 calculates the overfocus distance.

[0060] The flowchart of FIG. 4 shows the processes executed by the camera microcomputer 206 and the lens microcomputer 111 for pan focus control in Embodiment 3. The process starting from Step 501 shows the process executed by the camera microcomputer 206, and the process starting from Step 601 shows the process executed by the lens microcomputer 111.

[0061] The camera microcomputer 206 that starts the process in Step 501 waits for an operation of the pan focus setting switch by the user in Step 502, and proceeds to Step 503 when the operation is detected.

[0062] In Step 503, the camera microcomputer 206 transmits information (fourth information) regarding the allowable circle of confusion diameter to the lens microcomputer 111. Also in Step 504, the camera microcomputer 206 transmits information (fourth information) regarding the aperture value set in the pan-focus imaging to the lens microcomputer 111. The information regarding the allowable circle of confusion diameter and the aperture value may be information indicating the allowable circle of confusion diameter and the aperture value themselves, or may be information that can be converted into the allowable circle of confusion diameter and the aperture value in the lens microcomputer 111. Note that in the interchangeable lens 100, when the allowable circle of confusion diameter at the time of calculating the hyperfocal distance is determined, it may not be necessary to transmit information regarding the allowable circle of confusion diameter from the camera microcomputer 206 to the lens microcomputer 111.

[0063] Next, in Step 505, the camera microcomputer 206 transmits a pan-focus drive command to the lens microcomputer 111. Then, the camera microcomputer 206 ends the process in Step 506.

[0064] On the other hand, the lens microcomputer 111 that started the process from Step 601 receives information regarding the allowable circle of confusion diameter from the camera microcomputer 206 in Step 602, and further receives information regarding the aperture value from the camera microcomputer 206 in Step 603.

[0065] Next, the lens microcomputer 111 that received the pan-focus drive command from the camera microcomputer 206 in Step 604 proceeds to Step 605. In Step 605, the lens microcomputer 111 acquires the focal length of the current imaging lens from the zoom position data obtained from the zoom position detection unit 106. Then, the lens microcomputer 111 calculates (acquires) the hyperfocal distance by Equation (1) using the focal length and the allowable circle of confusion diameter and the aperture value obtained from the information received in Steps 602 and 603.

[0066] Next, in Step 606, the lens microcomputer 111 converts the overfocus distance obtained in Step 605 into a pan-focus position. The coefficient used for this conversion varies for each focal length and is selected based on the focal length or the zoom position data obtained from the focal length or zoom position detection unit 106.

[0067] Next, in Step 607, the lens microcomputer 111 calculates the driving amount from the current position of the focus lens 109 to the pan-focus position obtained in Step 606.

[0068] Next, in Step 608, the lens microcomputer 111 drives the focus lens 105 by the driving amount calculated in Step 607 in the focus control unit 109 to obtain a pan-focus state. Then, the lens microcomputer 111 ends the process in Step 609.

[0069] According to this embodiment, the lens microcomputer 111 performs the operations from the calculation of the overfocus distance to the conversion to the pan-focus position. Therefore, while reducing the processing performed by the camera microcomputer 206, it is possible to easily perform pan-focus imaging in the situation (at an arbitrary timing) intended by the user.

Example

[0070] Next, Example 4 will be described. In this example as well, the lens microcomputer 111 acquires the overfocus distance, but the processing load on the lens microcomputer 111 is suppressed.

[0071] The flowchart of FIG. 5 shows the processes executed by the camera microcomputer 206 and the lens microcomputer 111 for pan-focus control in Example 4. The process starting from Step 501 shows the process executed by the camera microcomputer 206, and this process is the same as that in Example 3. Also, the process starting from Step 701 shows the process executed by the lens microcomputer 111.

[0072] The lens microcomputer 111 that started processing in Step 701 performs the processing from Step 702 to Step 704. This processing is the same as the processing from Step 602 to Step 604 in the third embodiment.

[0073] In Step 705, the lens microcomputer 111 acquires the pan-focus position. The lens microcomputer 111 stores, as table data, data on the pan-focus position using the focal length (or zoom position), aperture value, and allowable confusion circle diameter as parameters. The lens microcomputer 111 reads from the table data the pan-focus position corresponding to the combination of the allowable confusion circle diameter and aperture value received from the camera microcomputer 206 in Steps 702 and 703 and the focal length (or zoom position) obtained from the zoom position data from the zoom position detection unit 106.

[0074] Next, in Step 706, the lens microcomputer 111 calculates the driving amount from the current position of the focus lens 109 to the pan-focus position read in Step 705.

[0075] Next, in Step 707, the lens microcomputer 111 drives the focus lens 105 by the driving amount calculated in Step 706 by the focus control unit 109 to obtain a pan-focus state. Then, the lens microcomputer 111 ends the processing in Step 708.

[0076] In this embodiment, table data on the pan-focus position for each combination of the focal length, aperture value, and allowable confusion circle diameter is stored in the lens microcomputer 111. When a pan-focus drive command is received, the target pan-focus position is read out and the focus lens 105 is driven. Thereby, the processing load on the lens microcomputer 111 can be reduced, and even if the processing capacity of the lens microcomputer 111 is low, pan-focus imaging can be easily performed at the situation (any timing) intended by the user. (Other Embodiments) The present invention can also be implemented by supplying a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. It can also be implemented by a circuit (for example, ASIC) that realizes one or more functions.

[0077] Each of the embodiments described above is merely a representative example, and various modifications and changes can be made to each embodiment when implementing the present invention.

Explanation of Reference Numerals

[0078] 100 interchangeable lens 106 zoom position detection unit 111 lens microcomputer 200 camera body 205 operation unit 206 camera microcomputer

Claims

1. An imaging device in which a lens device having a focus lens is detachably mounted, an imaging element, camera control means for communicating with the lens device and driving the focus lens in the lens device, wherein the camera control means, receives first information regarding the focal length of the lens device transmitted from the lens device, acquires the over-focus distance of the lens device using the first information, and transmits second information including information regarding the over-focus distance or information regarding the position of the focus lens according to the over-focus distance to the lens device. The imaging device is characterized by this.

2. The imaging device according to claim 1, wherein the camera control means acquires the over-focus distance using the first information, the allowable confusion circle diameter, and the aperture value set for the lens device.

3. The imaging device according to claim 2, wherein the camera control means transmits information regarding the aperture value to the lens device and drives the aperture of the lens device according to the information regarding the aperture value.

4. The camera control means, receives third information for acquiring the position of the focus lens according to the over-focus distance transmitted from the lens device, acquires the second information as information regarding the position of the focus lens according to the over-focus distance using the over-focus distance and the third information, and transmits the second information to the lens device. The imaging device according to any one of claims 1 to 3 is characterized by this.

5. A lens device detachably mounted on the imaging device according to claim 1, the focus lens, lens control means for communicating with the imaging device and driving the focus lens, wherein the lens control means, transmits the first information to the imaging device, receives the second information transmitted from the imaging device, and drives the focus lens to a position according to the over-focus distance based on the second information. The lens device is characterized by this.

6. The lens device has an aperture, the lens control means receives information regarding the aperture value transmitted from the imaging device, drives the focus lens to a position according to the over-focus distance, and drives the aperture according to the information regarding the aperture value. The lens device according to claim 5 is characterized by this.

7. The second information includes information regarding the over-focus distance, The lens control means The lens device according to claim 5 or 6, wherein the position of the focus lens is obtained using the information regarding the overfocus distance.

8. The lens control means transmits third information for obtaining the position of the focus lens corresponding to the overfocus distance to the imaging device, The lens device according to claim 5 or 6, wherein information regarding the position of the focus lens transmitted from the imaging device is received as the second information.

9. A control method for an imaging device having an image sensor, in which a lens device having a focus lens is detachably and communicably attached, the method comprising: receiving first information regarding the focal length of the lens device transmitted from the lens device; obtaining the overfocus distance of the lens device using the first information; transmitting second information including information regarding the overfocus distance or information regarding the position of the focus lens corresponding to the overfocus distance to the lens device.

10. A control method for a lens device detachably and communicably attached to an imaging device controlled by the control method according to claim 9, the method comprising: transmitting the first information to the imaging device; driving the focus lens to a position corresponding to the overfocus distance based on the second information transmitted from the imaging device.

11. A program characterized by causing a computer of the imaging device to execute a process according to the control method according to claim 9.

12. A program characterized by causing a computer of the lens device to execute a process according to the control method according to claim 10.

Images