Optical device, control method, and program

Abstract

To provide an optical instrument, a control method, and a program that can accurately correct an error in a focus detection result due to various aberrations of an optical system.SOLUTION: An optical instrument is removably attached to an imaging apparatus, and can change the amount of aberration of an optical system including a lens group by driving the lens group, and the optical instrument has: the optical system; a diaphragm unit; a control section that controls the lens group and the diaphragm unit; and a storage section that is used for light quantity adjustment performed by the diaphragm unit or focusing performed by the lens group and stores a plurality of pieces of optical information according to the amount of aberration. The control section selects one piece of optical information from the plurality of pieces of optical information on the basis of the amount of aberration and information for determining if the imaging apparatus is designed for at least one of the light quantity adjustment and focusing in the amount of aberration, and transmits the selected optical information to the imaging apparatus.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical device, a control method, and a program. [Background technology]

[0002] Conventionally, autofocus (hereinafter referred to as AF) is known, which adjusts the focus on a subject by driving a focus lens according to the in-focus position of the focus lens calculated from an AF evaluation value generated by an AF sensor. In AF, errors can occur in the focus detection result due to various aberrations in the optical system. Patent Document 1 discloses a method for suppressing errors in the focus detection result and performing high-precision focus adjustment by storing information about the imaging position of the optical system for each of a plurality of different spatial frequencies. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-074022 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the method of Patent Document 1, it is difficult to correct the focus detection result taking into account the influence of changes in various aberrations of the optical system.

[0005] An object of the present invention is to provide a control device, optical device, control method, and program that are capable of correcting errors in focus detection results caused by various aberrations in the optical system with high accuracy. [Means for solving the problem]

[0006] An optical device according to one aspect of the present invention is an optical device that is detachable from an imaging device and that is capable of changing an amount of aberration of an optical system including a lens group by driving the lens group, the optical device comprising: an optical system; an aperture unit; and a control unit that controls the lens group and the aperture unit., collection Multiple optical information according to the difference amount or a plurality of correction data according to the amount of aberration for correcting optical information and a storage unit that stores the the plurality of pieces of optical information or the optical information corrected by the plurality of correction data is used for adjusting the amount of light by the aperture unit or for adjusting the focus by the lens group; The control unit determines one of the plurality of pieces of optical information based on the amount of aberration and information for determining whether the imaging device supports at least one of light amount adjustment and focus adjustment in the amount of aberration. Or one of multiple correction data is selected and transmitted to the imaging device. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an optical device, a control method, and a program that can correct errors in focus detection results caused by various aberrations in the optical system with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of a camera system having an interchangeable lens as an example of an optical apparatus according to an embodiment of the present invention. [Figure 2] 10A and 10B are diagrams illustrating an example in which the amount of aberration of the imaging optical system is changed according to the trajectory of the focus lens. [Figure 3] 10 is a flowchart showing a method for transmitting optical information according to the amount of aberration of the imaging optical system of the first embodiment. [Figure 4] 10 is a flowchart showing a method for transmitting correction data according to the amount of aberration of the imaging optical system of the first embodiment. [Figure 5] 10 is a flowchart illustrating a method for transmitting optical information according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same components, and redundant explanations will be omitted.

[0010] 1 is a block diagram of a camera system having an interchangeable lens 100, which is an example of an optical apparatus according to an embodiment of the present invention. The camera system has the interchangeable lens 100 and a camera body (image capturing device) 200.

[0011] The interchangeable lens 100 is mechanically and electrically connected to the camera body 200 via a mount (not shown). The interchangeable lens 100 receives power from the camera body 200 via a power terminal provided on the mount, and uses the power received from the camera body 200 to control various actuators (described below) and a lens microcomputer (hereinafter referred to as lens microcomputer) 111.

[0012] The camera body 200 has an image sensor 201, a signal processing unit 202, a recording processing unit 203, a display unit 204, an operation unit 205, and a camera microcomputer (hereinafter referred to as camera microcomputer) 206.

[0013] The image sensor 201 photoelectrically converts a subject image formed by the imaging optical system in the interchangeable lens 100 and outputs an electrical signal (analog signal). In this embodiment, the image sensor 201 is used as a phase difference AF sensor. The analog signal from the image sensor 201 is converted into a digital signal by an A / D conversion circuit (not shown).

[0014] The signal processing unit 202 performs various image processing on the digital signal from the A / D conversion circuit to generate a video signal, and outputs the video signal to the recording processing unit 203 and the display unit 204. The signal processing unit 202 also generates, from the video signal, focus information indicating the contrast state of the subject image, that is, the focus state of the imaging optical system, and brightness information indicating the exposure state.

[0015] The recording processing unit 203 stores the video signal as still images or moving image data in an external memory or the like.

[0016] The display unit 204 displays the video signal as a live view image that can be used to check the composition, focus state, and the like.

[0017] The camera microcomputer 206 controls the camera body 200 in response to input from an imaging instruction switch and various setting switches included in the operation unit 205. The camera microcomputer 206 also includes a communication unit (not shown), and transmits control commands to the lens microcomputer 111 via the communication unit, such as control commands relating to light intensity adjustment by the aperture unit 103 in response to brightness information and focus adjustment by the focus lens 105 in response to focus information. The camera microcomputer 206 also transmits information relating to the camera body 200, including the ID and version of the camera body 200, to the lens microcomputer 111.

[0018] The interchangeable lens 100 has an imaging optical system, various control units that control various actuators (drive units) that drive the lens groups included in the imaging optical system, various operation rings that operate the lens groups, and a lens microcomputer (control unit) 111. Note that in this embodiment, the lens microcomputer 111 is provided inside the interchangeable lens 100, but it may also be configured as a control device separate from the interchangeable lens 100.

[0019] The imaging optical system includes a field lens 101, a zoom lens 102, an aperture unit 103, an image stabilization lens 104, a focus lens (first lens group) 105, and a floating lens (second lens group) 112. Although each lens is shown as a single lens in FIG. 1, each lens may be configured as a lens group consisting of multiple lenses.

[0020] The zoom lens 102 is movable along the optical axis O of the imaging optical system, and moves along the optical axis when a user operates a zoom operation ring connected to a zoom mechanism (not shown). Movement of the zoom lens 102 changes the focal length of the imaging optical system, thereby varying the magnification. The zoom lens position detection unit 106 detects the position of the zoom lens 102 using a position detection sensor such as a variable resistor, and outputs the detected position data of the zoom lens 102 to the lens microcomputer 111. The lens microcomputer 111 uses the acquired position data to control operations such as zoom tracking.

[0021] The aperture unit 103 includes aperture blades and sensors such as Hall elements. The state of the aperture blades is detected by the sensors and output to the lens microcomputer 111. The aperture control unit 107 outputs a drive signal in response to a command from the lens microcomputer 111 to drive an actuator such as a stepping motor or a voice coil motor. This allows the aperture unit 103 to adjust the amount of light.

[0022] The image stabilization lens 104 reduces image shake caused by camera shake or the like by moving in a direction perpendicular to the optical axis O of the imaging optical system. The image stabilization lens control unit 108 drives the anti-shake actuator by outputting a drive signal in response to a command from a lens microcomputer 111 that corresponds to shake detected by a shake sensor (not shown), such as a vibration gyroscope. This performs anti-shake processing that controls the shift operation of the image stabilization lens 104.

[0023] The focus lens 105 and the floating lens 112 are movable along the optical axis O of the imaging optical system. Position data of the focus lens 105 or the floating lens 112 detected using a position detection sensor such as a photointerrupter is output to a lens microcomputer 111. The focus lens control unit 109 and the floating lens control unit 113 output drive signals in response to commands from the lens microcomputer 111 to drive actuators such as stepping motors. This moves the focus lens 105 and the floating lens 112, and focus adjustment is performed. In addition, the focus lens 105 corrects image plane fluctuations that occur when the zoom lens 102 changes magnification.

[0024] The interchangeable lens 100 adjusts aberrations without changing the focal length or focus position by moving any of the lenses via the control unit of the respective lenses along the optical axis O. The lens microcomputer 111 stores the amount of aberration adjustment and transmits the amount of aberration adjustment to the camera microcomputer 206 via a communication unit (not shown) provided within the lens microcomputer 111.

[0025] The lens microcomputer 111 controls the operation of each unit within the interchangeable lens 100. The lens microcomputer 111 also receives control commands transmitted from the camera body 200 via the communication unit and receives requests to transmit lens data. The lens microcomputer 111 then performs lens control corresponding to the control commands and transmits lens data corresponding to the transmission requests to the camera body 200.

[0026] In response to a command related to light amount adjustment or focusing among the control commands, the lens microcomputer 111 issues commands to the aperture control unit 107, the focus lens control unit 109, and the floating lens control unit 113. The aperture control unit 107, the focus lens control unit 109, and the floating lens control unit 113 drive the aperture unit 103, the focus lens 105, and the floating lens 112, respectively, in response to the command. This performs AF processing that controls light amount adjustment by the aperture unit 103 and focus adjustment by the focus lens 105 and the floating lens 112.

[0027] Furthermore, the lens microcomputer 111 controls focus adjustment by driving the focus lens 105 via the focus lens control unit 109 in accordance with the amount of operation of the focus lens operation ring 110 .

[0028] Furthermore, the lens microcomputer 111 drives the focus lens 105 or the floating lens 112 via the focus lens control unit 109 or the floating lens control unit 113 in accordance with the amount of operation on the aberration adjustment ring (aberration amount operation unit) 114. This allows aberration adjustment. FIG. 2 is a diagram showing an example in which the amount of aberration of the imaging optical system changes in accordance with the trajectory of the focus lens 105. In this way, the amount of aberration can be adjusted without changing the focal length or the focus position by controlling the trajectories of the focus lens 105 and the floating lens 112. Note that when controlling the aberration adjustment, the lens to be driven is not limited to the focus lens 105 or the floating lens 112, and may be a lens for aberration adjustment.

[0029] The lens microcomputer 111 includes a storage unit (not shown) that stores optical information or correction data for correcting the optical information used when driving the lens group included in the imaging optical system (for example, in light intensity adjustment or AF processing). The lens microcomputer 111 transmits the optical information or correction data to the camera microcomputer 206 via a communication unit. The camera microcomputer 206 transmits a control command based on the optical information or correction data to the lens microcomputer 111. In addition, the lens microcomputer 111 drives the lens group, such as the aperture unit 103, the focus lens 105, or the floating lens 112, based on the control command from the camera microcomputer 206. [Example]

[0030] In this embodiment, a method will be described in which the lens microcomputer 111 transmits optical information corresponding to changes in the amount of aberration of the imaging optical system to the camera microcomputer 206.

[0031] 3, a method in which the lens microcomputer 111 transmits optical information selected from a plurality of pieces of optical information corresponding to changes in the amount of aberration of the imaging optical system to the camera microcomputer 206. Fig. 3 is a flowchart showing a method in this embodiment in which optical information corresponding to changes in the amount of aberration of the imaging optical system is transmitted.

[0032] This flow starts when the lens microcomputer 111 receives an optical information acquisition request from the camera microcomputer 206 via the communication unit.

[0033] In step S301, the lens microcomputer 111 stores the current amount of aberration of the imaging optical system in the storage unit.

[0034] In step S302, the lens microcomputer 111 determines whether the amount of aberration stored in the storage unit in step S301 is greater than a threshold value. The amount of aberration is determined based on the position of the lens. Any of the lenses shown in FIG. 1 may be used for the determination. In this embodiment, the amount of aberration is determined based on the positions of the focus lens 105 and the floating lens 112. The amount of aberration may also be determined based on the state of the aberration adjustment ring 114. If the amount of aberration is greater than the threshold value, the process proceeds to step S303; otherwise, the process proceeds to step S304. Note that if the amount of aberration is equal to the threshold value, it is possible to arbitrarily set which step to proceed to.

[0035] In step S303, the lens microcomputer 111 selects the first optical information as the optical information to be sent to the camera microcomputer 206. In this embodiment, the optical information is information (focus correction table) for correcting the focus position of the AF performed by the camera body 200. The optical information may also be information for correcting the amount of light in the imaging optical system performed by the camera body 200. Information regarding focal length and various aberrations may also be used as the optical information.

[0036] In step S304, the lens microcomputer 111 selects the second optical information as the optical information to be transmitted to the camera microcomputer 206.

[0037] In step S305, the lens microcomputer 111 transmits the optical information selected in step S303 or step S304 to the camera microcomputer 206 via the communication unit.

[0038] Note that this flow is started when the lens microcomputer 111 receives an optical information acquisition request from the camera microcomputer 206, but may be started regardless of whether the lens microcomputer 111 receives an optical information acquisition request.

[0039] Furthermore, although one threshold value is used in step S302, multiple threshold values ​​may be used. By setting multiple threshold values, it is possible to select one optical information from two or more optical information.

[0040] 3, the lens microcomputer 111 may transmit one piece of optical information selected from a plurality of pieces of optical information corresponding to changes in the amount of aberration of the imaging optical system to the camera microcomputer 206, but the present invention is not limited to this. The lens microcomputer 111 may also transmit correction data obtained by converting optical information (first optical information) used when driving a lens group included in the imaging optical system to the camera microcomputer 206.

[0041] A method in which the lens microcomputer 111 converts the first optical information and transmits one of a plurality of pieces of correction data corresponding to changes in the amount of aberration of the imaging optical system to the camera microcomputer 206 will be described below with reference to Fig. 4. Fig. 4 is a flowchart showing a method in this embodiment for transmitting correction data corresponding to the amount of aberration of the imaging optical system. In this embodiment, the correction data is an offset value for the first optical information.

[0042] This flow starts when the lens microcomputer 111 receives an optical information acquisition request from the camera microcomputer 206 via the communication unit.

[0043] In step S401, the lens microcomputer 111 stores the current amount of aberration of the imaging optical system in the storage unit.

[0044] In step S402, the lens microcomputer 111 determines whether the amount of aberration stored in the storage unit in step S401 is greater than a threshold value. If the amount of aberration is greater than the threshold value, the process proceeds to step S403; if not, the process proceeds to step S404. Note that if the amount of aberration is equal to the threshold value, it is possible to arbitrarily set which step to proceed to.

[0045] In step S403, the lens microcomputer 111 converts the first optical information through a first process to obtain first correction data.

[0046] In step S404, the lens microcomputer 111 converts the first optical information through a second process to obtain second correction data.

[0047] In the first process and the second process, the conversion of the first optical information may be performed using different offset values, or may be performed using different calculation formulas.

[0048] In step S405, the lens microcomputer 111 transmits the correction data acquired in step S403 or step S405 to the camera microcomputer 206 via the communication unit.

[0049] Note that this flow is started when the lens microcomputer 111 receives an optical information acquisition request from the camera microcomputer 206, but may be started regardless of whether the lens microcomputer 111 receives an optical information acquisition request.

[0050] According to the configuration of this embodiment, the lens microcomputer 111 can transmit appropriate optical information or correction data according to the amount of aberration to the camera body 200. Therefore, even when the camera microcomputer 206 changes the amount of aberration without changing the focal length or focus position of the interchangeable lens 100, errors in the focus detection results due to various aberrations in the optical system can be corrected with high precision. [Example]

[0051] In this embodiment, a method will be described in which the lens microcomputer 111 determines whether the camera body 200 is capable of controlling light intensity adjustment and focus adjustment when there is a large change in the amount of aberration in the imaging optical system, and transmits appropriate optical information.

[0052] FIG. 5 is a flowchart showing a method in which the lens microcomputer 111 of this embodiment determines whether the camera body 200 supports light intensity adjustment and focus adjustment control when there is a large change in the amount of aberration in the imaging optical system, and transmits appropriate optical information.

[0053] This flow starts when the camera microcomputer 206 starts up and starts communication with the lens microcomputer 111.

[0054] In step S501, the lens microcomputer 111 acquires information about the camera body 200, including the ID and version of the camera body 200, from the camera microcomputer 206. Note that in this embodiment, the information about the camera body 200 includes the ID and version of the camera body 200, but may also include information about the AF method and number of pixels of the camera body 200 together with or separately from this information.

[0055] In step S502, the lens microcomputer 111 determines whether or not an optical information acquisition request has been received from the camera microcomputer 206. If an optical information acquisition request has been received, the process proceeds to step S503; if not, the process of this step is repeated.

[0056] In step S503, the lens microcomputer 111 stores the current amount of aberration of the imaging optical system in the storage unit.

[0057] In step S504, the lens microcomputer 111 determines whether the amount of aberration stored in the storage unit in step S503 is greater than a threshold. If the amount of aberration is greater than the threshold, the process proceeds to step S505; if not, the process proceeds to step S506. Note that if the amount of aberration is equal to the threshold, it is possible to arbitrarily set which step to proceed to.

[0058] In step S505, the lens microcomputer 111 determines whether the camera body 200 supports control of light intensity adjustment and focus adjustment when there is a large change in the amount of aberration in the imaging optical system. In other words, it determines whether the camera microcomputer 206 is able to appropriately convert optical information in accordance with changes in the amount of aberration in the imaging optical system. The determination of whether or not support is made based on the information about the camera body 200 acquired in step S501. Furthermore, the determination may be made based on information about the camera body 200, such as the AF method and number of pixels of the camera body 200, in addition to or separately from the information about the camera body 200. If support is made (if the imaging device is in the first state), the process proceeds to step S506; if not, the process proceeds to step S507.

[0059] In step S506, the lens microcomputer 111 selects the first optical information (corresponding to the first optical information in the first embodiment) as the optical information to be transmitted to the camera microcomputer 206.

[0060] In step S507 , the lens microcomputer 111 selects the second optical information as the optical information to be transmitted to the camera microcomputer 206 .

[0061] In step S508, the lens microcomputer 111 transmits the optical information selected in step S506 or step S507 to the camera microcomputer 206 via the communication unit.

[0062] In this embodiment, the selected optical information is sent to the camera microcomputer 206, but as described in the first embodiment, correction data converted from the first optical information may be sent to the camera microcomputer 206.

[0063] In this embodiment, if the camera body 200 supports control of light intensity adjustment and focus adjustment when there is a large change in the amount of aberration in the imaging optical system, the lens microcomputer 111 does not need to store multiple pieces of optical information or multiple pieces of correction data for each change in the amount of aberration. This makes it possible to reduce consumption of storage capacity. This allows the interchangeable lens 100 to select appropriate processing for each camera body 200, thereby enabling appropriate control of light intensity adjustment and focus adjustment. [Other Examples] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0064] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0065] 105 focus lens 109 Focus lens control unit (drive unit) 111 Lens microcomputer (control unit, memory unit) 112 Floating Lens 113 Floating lens control unit (drive unit) 114 Aberration adjustment ring (aberration amount control part)

Claims

1. An optical device that is detachable from an imaging device and that is capable of changing the amount of aberration of an optical system including a lens group by driving the lens group, the optical system; Aperture unit; a control unit that controls the lens group and the aperture unit; a storage unit that stores a plurality of pieces of optical information corresponding to the amount of aberration or a plurality of pieces of correction data corresponding to the amount of aberration for correcting the optical information, the plurality of pieces of optical information or the optical information corrected by the plurality of pieces of correction data is used for light amount adjustment by the aperture unit or focus adjustment by the lens group, The control unit selects one piece of optical information from the plurality of pieces of optical information or one piece of correction data from the plurality of pieces of correction data based on the amount of aberration and information for determining whether the imaging device is compatible with at least one of the light intensity adjustment and the focus adjustment for the amount of aberration, and transmits the selected piece of optical information or one piece of correction data to the imaging device.

2. 2. The optical apparatus according to claim 1, wherein the amount of aberration is adjustable without changing the focus position.

3. 3. The optical apparatus according to claim 1, wherein the lens group includes a first lens group and a second lens group.

4. 4. The optical apparatus according to claim 3, wherein the amount of aberration is adjusted by adjusting the positions of the first lens group and the second lens group.

5. 5. The optical apparatus according to claim 1, wherein, when the imaging device is capable of correcting the optical information in accordance with the amount of aberration, the control unit transmits the optical information to the imaging device.

6. 2. A method for controlling an optical device according to claim 1, changing the amount of aberration based on an operation for changing the amount of aberration; a step of transmitting one of the plurality of pieces of optical information or one of the plurality of pieces of correction data to an imaging device according to the amount of aberration.

7. A program that causes a computer to execute the control method according to claim 6.

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