Communication method and interchangeable lens

Abstract

Conventional camera systems provide insufficient information regarding initialization. [Solution] A communication method for an interchangeable lens that has a movable member whose position relative to the camera body changes when attached to the camera body, which receives a request signal from the camera body requesting information indicating whether initialization of the movable member has been completed, and upon receiving the request signal, transmits a signal to the camera body indicating that initialization of the movable member has been completed, and after transmitting the signal indicating that initialization of the movable member has been completed, transmits a signal to the camera body indicating the position of the movable member.

Description

Technical Field

[0001] The present invention relates to a communication method and an interchangeable lens.

Background Art

[0002] A camera system including a camera body and an interchangeable lens detachable from the camera body is known. For example, Patent Document 1 describes a camera system including a camera main body and a camera head, which initializes the camera head.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the mechanism related to the initialization of the interchangeable lens attached to the camera, a mechanism different from the conventional technology is desired.

Means for Solving the Problems

[0005] A communication method according to an aspect of the present invention is a communication method for an interchangeable lens including a moving member, in a state of being attached to a camera body, wherein a relative position with respect to the camera body changes. The method includes receiving a request signal for requesting information indicating whether initialization of the moving member is completed from the camera body, and when receiving the request signal, transmitting a signal indicating that initialization of the moving member is completed to the camera body. When transmitting the signal indicating that initialization of the moving member is completed, transmission of information indicating the position of the moving member to the camera body is started. At least one Then, when the initialization is completed Each time the moving member Then ​Also, an interchangeable lens according to an aspect of the present invention is an interchangeable lens including a moving member whose relative position with respect to a camera body changes when attached to the camera body, and receives a request signal for requesting information indicating whether initialization of the moving member has been completed from the camera body. When the request signal is received Then , When the initialization is completed the moving member Each time a first communication unit that transmits a signal indicating that initialization of the moving member has been completed to the camera body, and a second communication unit that starts transmitting information indicating the position of the moving member to the camera body when transmitting a signal indicating that initialization of the moving member has been completed.

Brief Description of Drawings

[0006]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0007] (First Embodiment) FIG. 1 is a perspective view showing a lens-exchangeable camera system to which the present invention is applied. In FIG. 1, only the devices and apparatuses related to the present invention are shown, and illustration and description of other devices and apparatuses are omitted. The camera 1 is composed of a camera body 100 and an interchangeable lens 200 that can be attached to and detached from the camera body 100.

[0008] The camera body 100 is provided with a lens mount 101 to which the interchangeable lens 200 can be detachably attached. At a position near the lens mount 101 of the camera body 100 (on the inner peripheral side of the lens mount 101), a holding portion (electrical connection portion) 102 that holds contacts in a state of partially protruding to the inner peripheral side of the lens mount 101 is provided. A plurality of contacts are provided on this holding portion 102.

[0009] The interchangeable lens 200 is provided with a lens mount 201 to which the camera body 100 can be detachably attached, corresponding to the lens mount 101 on the body side. At a position near the lens mount 201 of the interchangeable lens 200 (on the inner peripheral side of the lens mount 201), a holding portion (electrical connection portion) 202 that holds contacts in a state of partially protruding to the inner peripheral side of the lens mount 201 is provided. A plurality of contacts are provided on this holding portion 202.

[0010] When the interchangeable lens 200 is attached to the camera body 100, the holding portion 102 provided with a plurality of contacts is electrically and physically connected to the holding portion 202 provided with a plurality of contacts. Both holding portions 102 and 202 are used for power supply from the camera body 100 to the interchangeable lens 200 and for transmission and reception of signals between the camera body 100 and the interchangeable lens 200.

[0011] Behind the lens mount 101 in the camera body 100, an imaging element 104 such as a CMOS or a CCD is provided. Above the camera body 100, a button 107 serving as an input device is provided. The user gives a shooting instruction, a setting instruction for shooting conditions, etc. to the camera body 100 using an input device such as the button 107.

[0012] Figure 2 is a cross-sectional view showing a lens-exchangeable camera system to which the present invention is applied. The interchangeable lens 200 includes an imaging optical system 210 that forms a subject image. The imaging optical system 210 is composed of a plurality of lenses 210a to 210c and a diaphragm 211. These plurality of lenses 210a to 210c include a focusing lens 210b for controlling the focus position of the subject image and a shake correction lens 210c for correcting image blur of the subject image.

[0013] Inside the interchangeable lens 200, a lens control unit 203 that controls each part of the interchangeable lens 200 is provided. The lens control unit 203 is composed of a microcomputer (not shown) and its peripheral circuits. Connected to the lens control unit 203 are a lens-side first communication unit 217, a lens-side second communication unit 218, a focusing lens driving unit 212, a shake correction lens driving unit 213, a diaphragm driving unit 214, a ROM 215, and a RAM 216.

[0014] The lens-side first communication unit 217 and the lens-side second communication unit 218 exchange data with the camera body 100 via the respective communication contacts of the holding units 102 and 202. The lens-side first communication unit 217 and the lens-side second communication unit 218 are respectively communication interfaces on the interchangeable lens 200 side. The lens control unit 203 uses these communication interfaces to perform various communications (hotline communication, command data communication) described later with the camera body 100 (body control unit 103 described later).

[0015] The focusing lens driving unit 212 has an actuator such as a stepping motor, for example, and drives the focusing lens 210b in response to a signal input to the focusing lens driving unit 212. Similarly, the shake correction lens driving unit 213 and the diaphragm driving unit 214 each have an actuator such as a voice coil motor, for example, and drive the shake correction lens 210c and the diaphragm 211 respectively in response to an input signal.

[0016] The focusing lens 210b is driven in the optical axis direction by the focusing lens driving unit 212. The shake correction lens 210c is driven in the directions perpendicular to the optical axis (X direction, Y direction) by the shake correction lens driving unit 213. The aperture 211 is driven by the aperture driving unit 214 so that the size of the aperture (aperture diameter) for passing the subject light changes. That is, each of these members is a driven member whose driven state changes by receiving a driving force from each driving unit and being driven. Here, the driven state refers to a state among the states peculiar to each driven member that changes when the driven member is driven. For example, in the case of the focusing lens 210b, the position in the optical axis direction, in the case of the shake correction lens driving unit 213, the position in a plane perpendicular to the optical axis, and in the case of the aperture 211, the aperture diameter (and the F value of the imaging optical system 210 that changes according to the aperture diameter) are included in the driven state.

[0017] In addition, driven members other than the above-described driven members (focusing lens 210b, shake correction lens 210c, aperture 211) may be provided in the interchangeable lens 200. For example, similar to the above-described focusing lens 210b, a zoom lens may be provided as a member movable in the optical axis direction of the imaging optical system 210, and a mechanism for electrically driving the zoom lens (so-called power zoom mechanism) may be provided in the interchangeable lens 200.

[0018] The ROM 215 is a non-volatile storage medium, and a predetermined control program and the like executed by the lens control unit 203 are stored in advance. The RAM 216 is a volatile storage medium and is used as a storage area for various data by the lens control unit 203.

[0019] The lens control unit 203 has, in software form, an initialization status transmission unit 221, a driven state transmission unit 222, and an initialization control unit 223. Each of these functional units is realized software-wise by the lens control unit 203 executing a predetermined control program stored in the ROM 215.

[0020] The initialization control unit 223 executes predetermined initialization processing for each of the plurality of driven members described above. The initialization status transmission unit 221 transmits, for each of these plurality of driven members, initialization status data indicating the status of the initialization processing (for example, status data indicating whether the execution of the initialization processing has been completed or not) to the camera body 100 at a predetermined cycle via a first transmission path (to be described in detail later). The driven state transmission unit 222 transmits driven state data indicating the driven states of the plurality of driven members described above to the camera body at a predetermined cycle via a second transmission path (to be described in detail later) different from the first transmission path. Here, a mechanism in which the initialization status transmission unit 221 transmits the initialization status data to the camera body 100 at a predetermined cycle will be described. The camera body 100 issues a command for requesting the initialization status data to the interchangeable lens 200 at a predetermined cycle until it receives a signal indicating the completion of the initialization processing from the interchangeable lens 200. The initialization status transmission unit 221 of the interchangeable lens responds with the prepared initialization status data to this request command. With such a mechanism, the initialization status transmission unit 221 transmits the initialization status data to the camera body 100 at a predetermined cycle.

[0021] On the front surface of the imaging element 104, a shutter 115 for controlling the exposure state of the imaging element 104 and an optical filter 116 combining an optical low-pass filter and an infrared cut filter are provided. The subject light that has passed through the imaging optical system 210 enters the imaging element 104 through the shutter 115 and the filter 116.

[0022] Inside the camera body 100, a body control unit 103 that controls each part of the camera body 100 is provided. The body control unit 103 is composed of a microcomputer (not shown), a RAM, and its peripheral circuits and the like.

[0023] The body control unit 103 is connected to a body-side first communication unit 117 and a body-side second communication unit 118. The body-side first communication unit 117 is connected to the holding unit 102 and can exchange data with the lens-side first communication unit 217 via a plurality of contacts provided in the holding unit 102. Similarly, the body-side second communication unit 118 can exchange data with the lens-side second communication unit 218. In other words, the body-side first communication unit 117 and the body-side second communication unit 118 are respectively communication interfaces on the body side. The body control unit 103 uses these communication interfaces to perform various communications (hotline communication, command data communication) described later with the interchangeable lens 200 (lens control unit 203).

[0024] On the back of the camera body 100, a display device 111 composed of an LCD panel or the like is arranged. The body control unit 103 displays an image of a subject (so-called through image) based on the output of the imaging element 104 and various menu screens for setting shooting conditions and the like on this display device 111.

[0025] The body control unit 103 has, in software form, an initialization status receiving unit 121, a driven state receiving unit 122, and a drive control unit 123. These functional units are realized software-wise when the body control unit 103 executes a predetermined control program. The initialization status receiving unit 121 receives initialization status data transmitted by the initialization status transmitting unit 221. The driven state receiving unit 122 receives driven state data representing the driven states of a plurality of driven members transmitted by the driven state transmitting unit 222. The drive control unit 123 executes control processing (described later) for each driven member based on the initialization status data received by the initialization status receiving unit 121.

[0026] (Description of the holding units 102 and 202) FIG. 3 is a schematic diagram showing details of the holding portions 102 and 202. In FIG. 3, the holding portion 102 is arranged on the right side of the lens mount 101 in accordance with the actual mount structure. That is, the holding portion 102 of the present embodiment is arranged at a position deeper than the mount surface of the lens mount 101 of the camera body 100 (a position on the right side of the lens mount 101 in FIG. 3). Similarly, the holding portion 202 is arranged on the right side of the lens mount 201, indicating that the holding portion 202 of the present embodiment is arranged at a position protruding from the mount surface of the lens mount 201 of the interchangeable lens 200. Since the holding portion 102 and the holding portion 202 are arranged in this way, when the mount surfaces of the lens mount 101 and the lens mount 201 are brought into contact with each other to mount and couple the camera body 100 and the interchangeable lens 200, the holding portion 102 and the holding portion 202 are connected, and the electrical contacts provided on both holding portions are also connected. Such a mount structure is well known, so further explanation and illustration are omitted.

[0027] As shown in FIG. 3, there are 12 contacts, BP1 to BP12, in the holding portion 102. Also, in the holding portion 202, there are 12 contacts, LP1 to LP12, respectively corresponding to the above 12 contacts.

[0028] The contact points BP1 and BP2 are connected to the first power supply circuit 130 within the camera body 100. The first power supply circuit 130 supplies the operating voltage for each part within the interchangeable lens 200 to the contact point BP1, excluding circuits (such as the focusing lens driving unit 212, the shake correction lens driving unit 213, the aperture driving unit 214, etc.) that have a driving system like an actuator and consume relatively large power. That is, the operating voltage for each part within the interchangeable lens 200, excluding the above-mentioned driving units, is supplied from the contact points BP1 and LP1. The voltage value that can be supplied to this contact point BP1 has a range from the minimum voltage value to the maximum voltage value (for example, a voltage range in the 3V range), but the standard supplied voltage value is a voltage value near the intermediate value between the maximum voltage value and the minimum voltage value. And thereby, the current value supplied from the camera body 100 side to the interchangeable lens 200 side is a current value within the range of approximately several 10 mA to several 100 mA in the power-on state.

[0029] The contact point BP2 is a ground terminal corresponding to the above-mentioned operating voltage applied to the contact point BP1. That is, the contact points BP2 and LP2 are the ground terminal voltages corresponding to the above-mentioned operating voltage.

[0030] In the following description, the signal line composed of the contact points BP1 and LP1 is called the signal line V33. Also, the signal line composed of the contact points BP2 and LP2 is called the signal line GND. These contact points LP1, LP2, BP1, BP2 constitute the power supply system contact points for supplying power from the camera body 100 side to the interchangeable lens 200 side.

[0031] The contact points BP3, BP4, BP5, and BP6 are connected to the body side first communication unit 117. The corresponding contact points LP3, LP4, LP5, and LP6 on the interchangeable lens 200 side are connected to the lens side first communication unit 217. The body side first communication unit 117 and the lens side first communication unit 217 use these contact points (communication system contact points) to transmit and receive data with each other. The details of the communication performed by the body side first communication unit 117 and the lens side first communication unit 217 will be described in detail later.

[0032] In the following description, the signal line composed of contact points BP3 and LP3 is referred to as signal line CLK. Similarly, the signal line composed of contact points BP4 and LP4 is referred to as signal line BDAT, the signal line composed of contact points BP5 and LP5 is referred to as signal line LDAT, and the signal line composed of contact points BP6 and LP6 is referred to as signal line RDY.

[0033] Contact points BP7, BP8, BP9, and BP10 are connected to the body-side second communication unit 118. The corresponding contact points LP7, LP8, LP9, and LP10 on the interchangeable lens 200 side are connected to the lens-side second communication unit 218. The lens-side second communication unit 218 uses these contact points (communication system contact points) to transmit data to the body-side second communication unit 118. The details of the communication between the body-side second communication unit 118 and the lens-side second communication unit 218 will be described in detail later.

[0034] In the following description, the signal line composed of contact points BP7 and LP7 is referred to as signal line HREQ. Similarly, the signal line composed of contact points BP8 and LP8 is referred to as signal line HANS, the signal line composed of contact points BP9 and LP9 is referred to as signal line HCLK, and the signal line composed of contact points BP10 and LP10 is referred to as signal line HDAT.

[0035] The contact points BP11 and BP12 are connected to the second power supply circuit 131 within the camera body 100. The second power supply circuit 131 supplies the drive voltage of a circuit (such as the focusing lens drive unit 212, shake correction lens drive unit 213, aperture drive unit 214, etc.) that has a drive system like an actuator and relatively high power consumption to the contact point BP12. That is, the drive voltage of the focusing lens drive unit 212, shake correction lens drive unit 213, and aperture drive unit 214 is supplied from the contact points BP12 and LP12. The voltage value that can be supplied to this contact point BP12 has a range from the minimum voltage value to the maximum voltage value, and all ranges are voltage values larger than the voltage value range that can be supplied to the aforementioned contact point BP1 (for example, the maximum voltage value that can be supplied to the contact point BP12 is about several times the maximum voltage value that can be supplied to the contact point BP1). That is, the voltage value supplied to the contact point BP12 is a voltage value with a different magnitude from the voltage value supplied to the above-mentioned contact point BP1. Note that the voltage value standardly supplied to the contact point BP12 is a voltage value near the intermediate value between the maximum voltage value and the minimum voltage value that can be supplied to the contact point BP12. And thereby, the current supplied from the camera body 100 side to the interchangeable lens 200 side becomes a current value of about 10 mA to several A in the power-on state.

[0036] The contact point BP11 is a ground terminal corresponding to the above drive voltage applied to the contact point BP12. That is, the contact points BP11 and LP11 are ground terminals corresponding to the above drive voltage.

[0037] In the following description, the signal line composed of the contact points BP11 and LP11 is called the signal line PGND. Also, the signal line composed of the contact points BP12 and LP12 is called the signal line BAT. These contact points LP11, LP12, BP11, and BP12 constitute power supply system contact points for supplying power from the camera body 100 side to the interchangeable lens 200 side.

[0038] As is clear from the magnitude relationship between the voltage values (current values) supplied to the above-mentioned contacts BP12 and LP12 and the voltage values (current values) supplied to the contacts BP1 and LP1, the difference between the maximum value and the minimum value of the current flowing through the contacts BP11 and LP11, which serve as the ground terminals for the voltages applied to these respective contacts, is larger than the difference between the maximum value and the minimum value of the current flowing through the contacts BP2 and LP2. This is because the power consumed by each drive unit having a drive system such as an actuator is larger than that of an electronic circuit such as the lens control unit 203 within the interchangeable lens 200, and because each drive unit does not consume power when there is no need to drive the driven member.

[0039] (Explanation of command data communication) The lens control unit 203 controls the lens-side first communication unit 217 to receive control data from the body-side first communication unit 117 and transmit response data to the body-side first communication unit 117 via the contacts LP3 to LP6, that is, the signal lines CLK, BDAT, LDAT, and RDY, in parallel at a predetermined first predetermined cycle (for example, 16 milliseconds in this embodiment). Hereinafter, the details of the communication performed between the lens-side first communication unit 217 and the body-side first communication unit 117 will be described.

[0040] In this embodiment, the communication performed between the lens control unit 203 and the lens-side first communication unit 217, and the body control unit 103 and the body-side first communication unit 117 is referred to as "command data communication". Also, the transmission path composed of the four signal lines (signal lines CLK, BDAT, LDAT, and RDY) used for the command data communication is referred to as the first transmission path. Further, the communication system for performing these command data communications is referred to as the "command data communication system".

[0041] Figure 4 is a timing chart showing an example of command data communication. The body control unit 103 and the first body-side communication unit 117 first check the signal level of the signal line RDY at the start (T1) of the command data communication. The signal level of the signal line RDY indicates the communication availability of the first lens-side communication unit 217. When the lens control unit 203 and the first lens-side communication unit 217 are in a non-communicable state, they output a signal of H (High) level from the contact LP6. That is, the signal level of the signal line RDY is set to the H level. When the signal line RDY is at the H level, the body control unit 103 and the first body-side communication unit 117 do not start communication until it becomes the L level. Also, the next process during communication is not executed.

[0042] If the signal line RDY is at the L (Low) level, the body control unit 103 and the first body-side communication unit 117 output a clock signal 401 from the contact BP3. That is, the clock signal 401 is transmitted to the first lens-side communication unit 217 via the signal line CLK. The body control unit 103 and the first body-side communication unit 117 output a body-side command packet signal 402, which is the first half of the control data, from the contact BP4 in synchronization with this clock signal 401. That is, the body-side command packet signal 402 is transmitted to the first lens-side communication unit 217 via the signal line BDAT.

[0043] Also, when the clock signal 401 is output to the signal line CLK, the lens control unit 203 and the first lens-side communication unit 217 output a lens-side command packet signal 403, which is the first half of the response data, from the contact LP5 in synchronization with the clock signal 401. That is, the lens-side command packet signal 403 is transmitted to the first body-side communication unit 117 via the signal line LDAT.

[0044] In response to the completion of transmission of the lens-side command packet signal 403, the lens control unit 203 and the first lens-side communication unit 217 set the signal level of the signal line RDY to the H level (T2). The lens control unit 203 starts a first control process 404 (described later), which is a process according to the content of the received body-side command packet signal 402.

[0045] When the first control process 404 is completed, the lens control unit 203 notifies the first communication unit 217 on the lens side of the completion of the first control process 404. In response to this notification, the first communication unit 217 on the lens side outputs a signal of level L from the contact LP6. That is, the signal level of the signal line RDY is set to level L (T3). In response to this change in the signal level, the body control unit 103 and the first communication unit 117 on the body side output a clock signal 405 from the contact BP3. That is, the clock signal 405 is transmitted to the first communication unit 217 on the lens side via the signal line CLK.

[0046] Synchronizing with this clock signal 405, the body control unit 103 and the first communication unit 117 on the body side output a body-side data packet signal 406, which is the latter half of the control data, from the contact BP4. That is, the body-side data packet signal 406 is transmitted to the first communication unit 217 on the lens side via the signal line BDAT.

[0047] Also, when the clock signal 405 is output to the signal line CLK, the lens control unit 203 and the first communication unit 217 on the lens side output a lens data packet signal 407, which is the latter half of the response data, from the contact LP5 in synchronization with the clock signal 405. That is, the lens-side data packet signal 407 is transmitted to the first communication unit 117 on the body side via the signal line LDAT.

[0048] In response to the completion of the transmission of the lens-side data packet signal 407, the lens control unit 203 and the first communication unit 217 on the lens side set the signal level of the signal line RDY to level H again (T4). The lens control unit 203 starts a second control process 408 (described later), which is a process according to the content of the received body-side data packet signal 406.

[0049] Here, the first control process 404 and the second control process 408 performed by the lens control unit 203 will be described.

[0050] For example, a case will be described where the received body-side command packet signal 402 requests specific data on the interchangeable lens side. As a first control process 404, the lens control unit 203 analyzes the content of the command packet signal 402 and executes a process of generating the requested specific data. Further, as a first control process 404, the lens control unit 203 also executes a communication error check process for simply checking whether there is an error in the communication of the command packet signal 402 from the number of data bytes using the checksum data included in the command packet signal 402. The signal of the specific data generated by this first control process 404 is output to the body side as a lens-side data packet signal 407. In this case, the body-side data packet signal 406 output from the body side after the command packet signal 402 is a dummy data signal (including checksum data) that has no particular meaning for the lens side. In this case, the lens control unit 203 executes a communication error check process as described above using the checksum data included in the body-side data packet signal 406 as a second control process 408.

[0051] Next, for example, a case will be described in which the received body-side command packet signal 402 is an instruction to drive a driven member on the lens side. For example, a case will be described in which the command packet signal 402 is an instruction to drive the focusing lens 210b, and the received body-side data packet signal 406 is the driving amount of the focusing lens 210b. The lens control unit 203, as the first control process 404, analyzes the content of the command packet signal 402 and generates an acknowledgment signal indicating that the content has been understood. Further, the lens control unit 203, as the first control process 404, also executes the communication error check process as described above using the checksum data included in the command packet signal 402. The acknowledgment signal generated in this first control process 404 is output to the body side as the lens-side data packet signal 407. Further, the lens control unit 203, as the second control process 408, analyzes the content of the body-side data packet signal 406 and executes the communication error check process as described above using the checksum data included in the body-side data packet signal 406.

[0052] When the second control process 408 is completed by the lens control unit 203, the lens control unit 203 notifies the lens-side first communication unit 217 of the completion of the second control process 408. As a result, the lens control unit 203 causes the lens-side first communication unit 217 to output a signal of L level from the contact LP6. That is, the signal level of the signal line RDY is set to the L level (T5).

[0053] When the received body-side command packet signal 402 is an instruction to drive a driven member on the lens side (such as a focusing lens) as described above, the lens control unit 203 causes the signal level of the signal line RDY to be set to the L level in the lens-side first communication unit 217, and causes the focusing lens driving unit 212 to execute a process of driving the focusing lens 210b by the driving amount.

[0054] The communication performed at the above-mentioned times T1 to T5 is one command data communication. As described above, in one command data communication, the body control unit 103 and the body-side first communication unit 117 each transmit one body-side command packet signal 402 and one body-side data packet signal 406. That is, although they are divided into two for processing convenience and transmitted, the body-side command packet signal 402 and the body-side data packet signal 406 together constitute one control data.

[0055] Similarly, in one command data communication, the lens control unit 203 and the lens-side first communication unit 217 each transmit one lens-side command packet signal 403 and one lens-side data packet signal 407. That is, the lens-side command packet signal 403 and the lens-side data packet signal 407 together constitute one response data.

[0056] As described above, the lens control unit 203 and the lens-side first communication unit 217 perform reception of control data from the body-side first communication unit 117 and transmission of response data to the body-side first communication unit 117 in parallel. The contacts LP6 and BP6 used for command data communication are contacts through which an asynchronous signal (signal level of the signal line RDY, either H (High) level or L (Low) level) that is not synchronized with other clock signals is transmitted.

[0057] (Explanation of hotline communication) The lens control unit 203 controls the lens-side second communication unit 218 to transmit lens position data to the body-side second communication unit 118 via the contacts LP7 to LP10, that is, the signal lines HREQ, HANS, HCLK, and HDAT. Hereinafter, the details of the communication performed between the lens-side second communication unit 218 and the body-side second communication unit 118 will be described.

[0058] In this embodiment, the communication performed between the lens control unit 203 and the second lens-side communication unit 218, and the body control unit 103 and the second body-side communication unit 118 is referred to as "hotline communication". Also, the transmission path consisting of the four signal lines (signal lines HREQ, HANS, HCLK, and HDAT) used for hotline communication is referred to as the second transmission path. Further, the communication system for performing these hotline communications is referred to as the "hotline communication system".

[0059] Figure 5 is a timing chart showing an example of hotline communication. The body control unit 103 of this embodiment is configured to start hotline communication every second predetermined period (for example, 1 millisecond in this embodiment). This period is shorter than the period for performing command data communication. Figure 5(a) is a diagram showing the state where hotline communication is repeatedly executed every predetermined period Tn. Figure 5(b) shows an enlarged view of the period Tx of a certain one-time communication among the repeatedly executed hotline communications. Hereinafter, the procedure of hotline communication will be described based on the timing chart of Figure 5(b).

[0060] The body control unit 103 and the second body-side communication unit 118 first output a signal of L level from the contact point BP7 at the start of hotline communication (T6). That is, the signal level of the signal line HREQ is set to the L level. The second lens-side communication unit 218 notifies the lens control unit 203 that this signal has been input to the contact point LP7. In response to this notification, the lens control unit 203 starts the execution of the generation process 501 for generating lens position data. The generation process 501 is a process in which the lens control unit 203 causes a focusing lens position detection unit (not shown) to detect the position of the focusing lens 210b and generates lens position data representing the detection result.

[0061] When the lens control unit 203 finishes executing the generation process 501, the lens control unit 203 and the second lens-side communication unit 218 output a signal of L level from the contact LP8 (T7). That is, the signal level of the signal line HANS is set to the L level. In response to this signal being input to the contact BP8, the body control unit 103 and the second body-side communication unit 118 output a clock signal 502 from the contact BP9. That is, the clock signal is transmitted to the second lens-side communication unit 218 via the signal line HCLK.

[0062] Synchronizing with this clock signal 502, the lens control unit 203 and the second lens-side communication unit 218 output a lens position data signal 503 representing lens position data from the contact LP10. That is, the lens position data signal 503 is transmitted to the second body-side communication unit 118 via the signal line HDAT.

[0063] When the transmission of the lens position data signal 503 is completed, the lens control unit 203 and the second lens-side communication unit 218 output a signal of H level from the contact LP8. That is, the signal level of the signal line HANS is set to the H level (T8). In response to this signal being input to the contact BP8, the second body-side communication unit 118 outputs a signal of H level from the contact LP7. That is, the signal level of the signal line HREQ is set to the H level (T9).

[0064] The communication performed at the above-mentioned times T6 to T9 is one-time hotline communication. As described above, in one-time hotline communication, one lens position data signal 503 is transmitted by the lens control unit 203 and the second lens-side communication unit 218. The contacts LP7, LP8, BP7, and BP8 used for hotline communication are contacts through which asynchronous signals that are not synchronized with other clock signals are transmitted. That is, the contacts LP7 and BP7 are contacts through which asynchronous signals (the signal level of the signal line HREQ / H (High) level or L (Low) level) are transmitted, and the contacts LP8 and BP8 are contacts through which asynchronous signals (the signal level of the signal line HANS / H (High) level or L (Low) level) are transmitted.

[0065] Note that the command data communication and the hotline communication can be executed either simultaneously or partially in parallel. That is, either one of the lens-side first communication unit 217 and the lens-side second communication unit 218 can communicate with the camera body 100 even when the other is communicating with the camera body 100.

[0066] (Explanation of the processing executed after power-on) When the user turns on the power of the camera 1 (for example, an operation of turning on a power switch not shown in the figure), the lens control unit 203 (initialization control unit 223) executes the initialization processing of each part of the interchangeable lens 200. Similarly, the body control unit 103 also executes the initialization processing of each part of the camera body 100.

[0067] In this initialization processing, the lens control unit 203 (initialization control unit 223) first initializes the lens-side first communication unit 217 and the lens-side second communication unit 218. Similarly, the body control unit 103 first initializes the body-side first communication unit 117 and the body-side second communication unit 118. Through these processes, data communication (command data communication and hotline communication) can be performed between the camera body 100 and the interchangeable lens 200.

[0068] After initializing each communication unit, the lens control unit 203 (initialization control unit 223) starts initializing a plurality of driven members included in the interchangeable lens 200. The interchangeable lens 200 of the present embodiment includes a plurality of driven members (a focusing lens 210b, an anti-shake lens 210c, and a diaphragm 211). After the power of the camera 1 is turned on, the body control unit 103 and the lens control unit 203 cannot execute normal control processing on these driven members until the execution of the predetermined initialization processing by the initialization control unit 223 is completed. Examples of normal control processing include the transmission processing of the driven state by the driven state transmission unit 222 and the driving processing by the drive control unit 123.

[0069] The initialization control unit 223 of this embodiment sequentially executes the initialization processes of the respective driven members in the order of the aperture 211, the shake correction lens 210c, and the focusing lens 210b. The camera body 100 (body control unit 103) cannot execute processes involving these driven members until the initialization process by the initialization control unit 223 is completed. For example, until the initialization of the aperture 211 is completed, the camera body 100 (body control unit 103) cannot freely change the aperture diameter of the aperture 211, so processes such as exposure control cannot be performed.

[0070] In this embodiment, the initialization status transmission unit 221 transmits initialization status data representing the initialization status of each driven member to the camera body 100 (initialization status reception unit 121) at predetermined intervals. The body control unit 103 reads the initialization status data received by the initialization status reception unit 121 and sequentially starts control processes for the driven members for which initialization has been completed. For example, the drive control unit 123 does not execute control processes for the driven members indicated by the initialization status data as having incomplete execution of the initialization process.

[0071] FIG. 6 is a diagram showing the structure of information (data) representing the initialization status. When the initialization of each communication unit is completed, the body control unit 103 transmits the initialization status request command (data) 50 shown in FIG. 6(a) from the body-side first communication unit 117 to the interchangeable lens 200 at predetermined intervals. When the lens-side first communication unit 217 receives this initialization status request command (data) 50, it transmits the initialization status information (data) 60 shown in FIG. 6(b) to the body-side first communication unit 117. That is, the initialization status transmission unit 221 transmits initialization status information (data) 60 indicating whether the execution of the initialization process for each of the plurality of driven members is completed or incomplete to the body-side first communication unit 117 by the lens-side first communication unit 217 at predetermined intervals (for example, 16 milliseconds). In the command data communication shown in FIG. 4, the initialization status request command (data) 50 corresponds to the body-side command packet signal 402, and the initialization status information (data) 60 corresponds to the lens-side data packet signal 407.

[0072] In FIG. 6, the area marked as "N / A" is an area where there is no data definition. That is, any data can be entered in the location marked as "N / A". The body-side first communication unit 117 and the lens-side first communication unit 217 simply ignore the data stored in this area.

[0073] The initialization status request command (data) 50 shown in FIG. 6(a) is 2-byte data. The lower 1-byte is an identification integer 51 indicating that this data is the initialization status request command (data) 50. In FIG. 6(a), as an example, this identification integer 51 is set to the hexadecimal number "60H", but other communications may be used as long as it is possible to identify that it is the initialization status request command (data) 50.

[0074] The initialization status information (data) 60 shown in FIG. 6(b) is 2-byte data. The lower 1-byte is an identification integer 61 indicating that this data is the initialization status information (data) 60. The 8th bit is a flag 62 indicating whether the initialization process of the aperture 211 has been completed or not. When the initialization process of the aperture 211 is not completed, the initialization status transmission unit 221 transmits the initialization status information (data) 60 with the flag 62 being 0. Similarly, the 9th bit is a flag 63 indicating whether the initialization process of the shake correction lens 210c has been completed or not, and the 10th bit is a flag 64 indicating whether the initialization process of the focusing lens 210b has been completed or not.

[0075] FIG. 7 is a time chart showing the execution order of the initialization process after power-on. When a power-on operation is performed on the camera 1 at time T10, the body control unit 103 starts the initialization process 71 of each communication unit. Similarly, the lens control unit 203 (initialization control unit 223) also starts the initialization process 72 of each communication unit.

[0076] When the initialization process 71 of each communication unit is completed, the body control unit 103 starts transmitting the above-described initialization status request command (data) 50. Thereafter, until the control process 78 of the focusing lens 210b described later is completed (that is, during the period Ti), the body control unit 103 repeatedly transmits the initialization status request command (data) 50 at a predetermined cycle.

[0077] When the initialization process 72 of each communication unit is completed, the lens control unit 203 (initialization control unit 223) starts the initialization process 73 of the aperture 211. The initialization process 73 of the aperture 211 includes, for example, the origin setting process of an aperture actuator (not shown) that drives the aperture 211. This process is a process of driving (applying drive) the aperture actuator to drive the aperture 211 to the aperture open position (a position where it abuts against the mechanical limit provided on the aperture open side where the aperture is fully open). Until the execution of the initialization process 73 of the aperture 211 by the initialization control unit 223 is completed, each time the initialization status request command (data) 50 is transmitted from the camera body 100, the lens control unit 203 (initialization status transmission unit 221) causes the lens-side first communication unit 217 to transmit the initialization status information (data) 60 in which the flags 62, 63, and 64 are all 0 to the camera body 100.

[0078] In this embodiment, there are two types of initialization processes for the aperture 211. One of them is the initialization process 1 when the power switch on the camera body 100 side is turned off from the "power-off state" and then the power-on operation (startup) is performed. The other is the initialization process 2 when the camera body is started from the "sleep state" in which the power switch on the camera body side remains ON but the camera body has shifted to the low power consumption state. Here, the position of the aperture 211 (control aperture position) before entering the sleep state is stored in the memory in the lens control unit 203 again when shifting to the sleep state.

[0079] The initialization process 1 is the origin setting process of an aperture actuator (not shown) that drives the aperture 211 as described above.

[0080] On the other hand, after the aperture actuator origin setting process as described above, the initialization process 2 is a process of driving and controlling the aperture 211 to the aperture position (control aperture position) before the transition to the sleep state stored in the memory in the lens control unit 203 as described above.

[0081] The body control unit 103 recognizes whether the camera body is in the power-off state or the sleep state, and when sending an initialization start instruction to the lens control unit 203, it transmits information (parameter) indicating whether to perform the initialization process 1 or the initialization process 2 to the lens control unit 203. The lens-side control unit 203 performs one of the initialization processes 1 and 2 based on this parameter.

[0082] When the execution of the initialization process 73 of the aperture 211 is completed (that is, when the initialization of the aperture 211 is completed and the normal aperture control becomes possible), the initialization status transmission unit 221 starts to transmit the initialization status information (data) 60 in which the flag 61 is 1. When the body control unit 103 receives the initialization status information (data) 60 in which the flag 61 is 1, it causes the drive control unit 123 to start the execution of the control process 74 of the aperture 211. The control process of the aperture 211 includes, for example, a photometry calculation process for obtaining photometry information necessary for performing exposure control based on the output from the imaging element 104 in the body, and an acquisition process of aperture position information for detecting the current position of the aperture 211. Further, the control process of the aperture 211 may include a shooting aperture control process for changing and controlling the aperture 211 to the shooting aperture value to be controlled during shooting according to the shooting mode and shooting conditions such as the above-described photometry information (subject brightness).

[0083] Subsequently, the lens control unit 203 (initialization control unit 223) executes the initialization process 75 of the shake correction lens 210c and the initialization process 77 of the focusing lens 210b in sequence following the initialization process of the aperture 211. That is, the lens control unit 203 (initialization control unit 223) in the present embodiment completes the initialization process of the aperture 211 earlier than the initialization processes of other driven members. Each time these initialization processes are completed, the initialization status transmission unit 221 changes each flag (flag 62, flag 63) of the initialization status information (data) 60 to be transmitted from 0 to 1. After detecting such a change in each flag (i.e., the end of each initialization process), the body control unit 103 causes the drive control unit 123 to perform control processing (for example, control processing 76 of the shake correction lens 210c (for example, the centering operation of the shake correction lens and the operation of acquiring the position information of the shake correction lens associated therewith via the command data communication system instead of the above-mentioned hotline communication system) and control processing 78 of the focusing lens 210b (for example, the process of clearing data related to the focusing process (for example, defocus information indicating the focus shift stored for the previous focusing process) stored in the in-body memory from the memory)) on the driven member determined to be able to be controlled other than the initialization process according to each flag. When the initialization processes of each driven member shown in FIG. 7 are completed, and further when all the control processes of each driven member are completed, if an operation (for example, a half-press / full-press operation on the release button) is performed on the operation member that instructs the start of shooting, the camera 1 becomes in a state where shooting is possible through shooting preparation operations (such as focusing lens control, shake correction lens control, aperture control).

[0084] The initialization process 77 of the above-described focusing lens 210b includes the origin detection process of a focusing lens actuator (not shown) that drives the focusing lens, similar to the initialization process 73 of the above-described aperture 211. This origin detection process is a process of driving the focusing lens to a preset reference position of the focusing lens (for example, the tele end position, or the wide end position, etc.). Whether the focusing lens 210b has reached the reference position is detected by a sensor (a photo interrupter not shown) provided in the interchangeable lens, and the lens control unit 203 controls the stop of the focusing lens actuator based on the detection result of this sensor.

[0085] Note that the initialization process 77 of the focusing lens 210b also has two types of processes (initialization process 1 when powering on (starting up) from the "power-off state" and initialization process 2 when starting up the camera body from the "sleep state"), similar to the initialization process 73 of the above-described aperture 211. The contents of the initialization processes 1 and 2 are the same as those of the initialization process 73 of the aperture 211, and the only difference is whether the driving target is the aperture 211 or the focusing lens 210b, so the description here is omitted.

[0086] On the other hand, the initialization process 75 of the shake correction lens 210c is a process of calculating a correction value for correcting the output of a position detection sensor for detecting the position of the shake correction lens 210c. In the present embodiment, a low-cost sensor (for example, a Hall sensor) is used as the position detection sensor of the shake correction lens 210c. The output of such a position detection sensor varies due to fluctuations in the ambient temperature. Therefore, in order to perform appropriate position detection regardless of the ambient temperature, a process of correcting the output of the position detection sensor according to the ambient temperature is required. In the initialization process 75, as this correction process, a correction value based on the ambient temperature is calculated and stored in the memory of the lens control unit 203. The process up to the storage process of this correction value is the initialization process 75. Then, when actually detecting the position of the shake correction lens 210c, the output of the position detection sensor for detecting the position of the shake correction lens 210c is corrected based on the correction value stored in the memory of the lens control unit 203. Note that the ambient temperature is detected by a temperature sensor (not shown) provided on the circuit board inside the lens.

[0087] Note that in the initialization process 75 in the present embodiment, the origin setting process of the shake correction lens 210c (a process of driving the shake correction lens 210c to a predetermined reference position, for example, a process of driving the center of the shake correction lens 210c to coincide with the optical axis center of the interchangeable lens 200) is not performed for energy saving.

[0088] (Description of the driven state data) FIG. 8 is a diagram showing the structure of the driven state information (data). The driven state information (data) is information (data) representing the driven states of a plurality of driven members included in the interchangeable lens 200. The driven state transmission unit 222 transmits the driven state information (data) 80 shown in FIG. 8 to the camera body 100 (driven state reception unit 122) at a predetermined period (for example, 1 millisecond). The driven state information (data) 80 is transmitted by hot-line communication. That is, the driven state information (data) 80 is transmitted from the lens-side second communication unit 218 to the body-side second communication unit 118 via the second transmission path. The driven state transmission unit 222 starts transmitting the driven states of the respective driven members after the initialization of all the driven members is completed. That is, the transmission of the driven state information (data) 80 is not started until the initialization process of each driven member by the initialization control unit 223 is completed. In other words, the driven state reception unit 122 on the camera body 100 side uses the above-described hot-line communication system to send a request signal to the interchangeable lens 200 after the initialization status information (data) 60 indicating that the initialization of all the driven members is completed is received by the initialization status reception unit 121, and starts receiving the driven state information (data) 80. Here, a mechanism in which the driven state transmission unit 222 transmits the initialization status data to the camera body 100 at a predetermined period (every second period) will be described. The camera body 100 sends a signal (request signal) for requesting the driven state information (data) to the interchangeable lens 200 every second period (for example, 1 msec). The driven state transmission unit 222 of the interchangeable lens prepares in response to this request signal and responds with the driven state information (data). With such a mechanism, the driven state transmission unit 222 transmits the driven state information (data) to the camera body 100 at a second predetermined period.

[0089] The driven state information (data) 80 is 4-byte data consisting of the position data 81 of the focusing lens 210b, the aperture diameter data 82 of the diaphragm 211, and the position data 83 of the shake correction lens 210c. The position data 81 of the focusing lens 210b is a 1-byte integer, and values from 0 to 255 correspond to each position from the closest position to the infinite position. Similarly, the aperture diameter data 82 of the diaphragm 211 is a 1-byte integer, and values from 0 to 255 correspond to each position from the wide open diaphragm (maximum aperture diameter) to the minimum diaphragm (minimum aperture diameter). The position data 83 of the shake correction lens 210c is data formed by combining two 1-byte integers. The position of the shake correction lens 210c in a plane perpendicular to the optical axis of the imaging optical system 210 corresponds to values from 0 to 255 in the X-axis direction and values from 0 to 255 in the Y-axis direction, respectively.

[0090] The body control unit 103 obtains the current driven state of each driven member by referring to the driven state data 80 received by the driven state receiving unit 122. Then, based on the driven state obtained here, the drive control unit 123 is made to perform drive control. For example, when driving the focusing lens 210b, it is determined whether the focusing lens 210b has been driven to the target position by referring to the driven state data 80.

[0091] (Explanation of the process from the power-on operation until shooting becomes possible) FIG. 9 is a flowchart showing the process from the power-on operation until shooting becomes possible. The left side of FIG. 9 shows the process executed by the body control unit 103, and the right side of FIG. 9 shows the process executed by the lens control unit 203. First, the process executed by the body control unit 103 will be described.

[0092] In step S100, the body control unit 103 receives a power-on operation by the user. In step S110, the body control unit 103 executes initialization processing for the body-side first communication unit 117 and the body-side second communication unit 118. In step S120, the body control unit 103 outputs a predetermined lens activation signal to the interchangeable lens 200 via the contacts of the holding unit 102. In step S130, the body control unit 103 causes the body-side first communication unit 117 to transmit a predetermined initialization start instruction.

[0093] In step S140, the body control unit 103 determines whether or not a predetermined period (for example, 16 milliseconds) has elapsed since the execution of step S130. The body control unit 103 repeats the processing of step S140 until the predetermined period has elapsed. If the predetermined period has elapsed, the process proceeds to step S150. In step S150, the body control unit 103 transmits an initialization status request command (data) 50 to the interchangeable lens 200. In step S160, the initialization status reception unit 121 receives initialization status information (data) 60. In step S170, the body control unit 103 refers to the initialization status information (data) 60 received in step S160 and determines whether or not the initialization status has changed from the previously received initialization status information (data) 60. If the initialization status has not changed, the process proceeds to step S140 and waits for a predetermined period to elapse since the execution of step S170. On the other hand, if the initialization status has changed, the process proceeds to step S180. In step S180, the drive control unit 123 executes predetermined control processing on the driven member whose initialization status has changed. In step S190, the body control unit 103 determines whether or not the initialization of all driven members has been completed. If there are remaining uninitialized driven members, the process returns to step S140 and waits for a predetermined period to elapse since the execution of step S190. On the other hand, if the initialization of all driven members has been completed, the process proceeds to step S200 and shifts the camera body 100 to a photographable state.

[0094] Next, the processing executed by the lens control unit 203 will be described. In step S210, a lens activation signal is input from the camera body 100. In response to this signal, the lens control unit 203 starts the activation process. In step S220, the initialization control unit 223 executes the initialization process of the first lens-side communication unit 217 and the second lens-side communication unit 218. In step S230, the lens control unit 203 receives an initialization start instruction from the camera body 100. In step S240, the initialization control unit 223 sequentially starts the initialization process of each driven member. The initialization control unit 223 first starts the initialization process of the aperture 211, and when this is completed, sequentially starts the initialization process of the other driven members. As described above, the initialization control unit 223 executes only one initialization process at a time.

[0095] In step S250, the lens control unit 203 determines whether or not it has received an initialization status request command (data) 50 from the camera body 100. The lens control unit 203 repeats step S250 until it receives the initialization status request command (data) 50. When the initialization status request command (data) 50 is received, the process proceeds to step S260. In step S260, the initialization status transmission unit 221 transmits the initialization status information (data) 60 to the camera body 100. In step S270, the lens control unit 203 determines whether or not all the flags of the initialization status information (data) 60 transmitted immediately before in step S260 are all 1. If a negative determination is made in step S270, the process proceeds to step S250. On the other hand, when the initialization status information (data) 60 with all flags being 1 has been transmitted, the process proceeds to step S280. In step S280, the lens control unit 203 shifts the interchangeable lens 200 to the photographable state.

[0096] According to the camera system according to the first embodiment described above, the following operational effects can be obtained. (1) The initialization control unit 223 executes a predetermined initialization process for each of the plurality of driven members. The initialization status transmission unit 221 transmits initialization status information (data) indicating whether the execution of the initialization process for each of the plurality of driven members is completed or not to the camera body 100. Since the initialization status is transmitted from the interchangeable lens 200 to the camera body 100 in this way, the time required to detect the completion of the initialization of the interchangeable lens can be shortened.

[0097] Also, according to the present embodiment, the initialization status information (data) is transmitted to the camera body 100 via the first transmission path (command data communication system) at a predetermined period (in a form corresponding to a request command issued from the camera body side at a first predetermined period, for example, 16 msec) determined in advance. Since the initialization status is periodically transmitted from the interchangeable lens 200 to the camera body 100 at a predetermined period in this way, the time required to detect the completion of the initialization of the interchangeable lens can be shortened.

[0098] Also, after the initialization of each driven member is completed, the driven state transmission unit 222 transmits driven state data indicating the driven state of the driven member to the camera body 100 via the second transmission path (hot line communication system) at a predetermined period. By doing so, the camera body 100 can quickly know the state of the driven member immediately after the completion of the initialization process.

[0099] (2) The initialization control unit 223 completes the initialization process of the aperture 211 earlier than the initialization processes of the other driven members. The initialization process of the aperture member in the present embodiment is a process of setting the aperture 211 to either aperture open (initialization process 1) or the shooting aperture opening stored before sleep (initialization process 2), and the aperture 211 is initially set to a photometry preparation state (open photometry or photometry with aperture stop-down to the shooting aperture) according to the situation. By doing so, without waiting for the initialization of the other driven members, the camera body side can start preparing for the photometry operation (such as photometry calculation processing based on the above-described imaging element output), and the time until the shooting enable state is reached can be shortened.

[0100] (3) The initialization status transmission unit 221 of the interchangeable lens 200 transmits initialization status data 60 indicating the initialization status of a plurality of driven members to the camera body 100 at a predetermined cycle. By doing so, the camera body 100 can surely grasp the status of each driven member every time, perform the body-side preparation operation accordingly, and as a result, can shorten the time until it becomes in a state where shooting is possible.

[0101] (4) The initialization control unit 223 executes only one of the initialization processes of a plurality of driven members simultaneously in a predetermined order. By doing so, it becomes possible to always keep the execution completion order of the initialization processes of each driven member constant, and the control becomes easier.

[0102] (5) After the initialization status reception unit 121 receives the initialization status data 60 indicating that the initialization of the driven member has been completed, the driven state reception unit 122 starts receiving the driven state of the driven member. By doing so, it is possible to prevent receiving an inaccurate driven state from an uninitialized driven member.

[0103] (6) The drive control unit 123 does not execute a predetermined control process on a driven member indicated by the initialization status data 60 as having an incomplete initialization process. By doing so, it is possible to prevent performing inappropriate drive control on an uninitialized driven member.

[0104] (Second Embodiment) The camera system according to the second embodiment of the present invention has the same configuration as the camera system according to the first embodiment. However, compared with the first embodiment, the order (procedure) in which the initialization control unit 223 executes the initialization processes of a plurality of driven members is different. In the second embodiment, the same reference numerals are given to the same contents as those in the first embodiment.

[0105] FIG. 10 is a time chart showing the execution order of the initialization process after power-on. The initialization control unit 223 according to the present embodiment executes the initialization process 72 of each communication unit and then executes the initialization processes of a plurality of driven members in parallel. That is, the initialization process 73 of the aperture 211, the initialization process 75 of the shake correction lens 210c, and the initialization process 77 of the focusing lens 210b are simultaneously started. Each of these initialization processes takes a different time to execute, and the body control unit 103 starts the execution of the control process of the driven member in order from the driven member whose initialization is completed. For example, as shown in FIG. 10, when the aperture initialization process 73 ends first, the execution of the aperture control process 74 is started accordingly. Then, when the execution of the aperture control process 74 is completed, it waits until the initialization processes of other driven members are completed. And each time the execution of the initialization process is completed, the corresponding control process (for example, the shake correction lens control process 76 and the focusing lens control process 78) is executed.

[0106] Note that, as in the case of the initialization processes 73 and 77, there are two types of processes (the process at the time of startup from the "power-off state" and the process at the time of startup from the "sleep state"), which is the same as in the first embodiment.

[0107] Also, the operation flow of the second embodiment is substantially the same as the operation flow shown in FIG. 9. In FIG. 9, the difference from the operation flow in the first embodiment is that in the second embodiment, the initialization control unit 223 "simultaneously starts" the initialization processes of the respective driven members in step S240.

[0108] According to the camera system according to the second embodiment described above, in addition to the effects obtained by the camera system according to the first embodiment, the following effects can be obtained. (1) The initialization control unit 223 simultaneously starts the initialization processes of a plurality of driven members. As a result, a plurality of initialization processes can be processed in parallel, so that the time required for the completion of all initializations can also be shortened, and accordingly, the time until the photographable state is reached can be shortened.

[0109] (2) The initialization control unit 223 starts the initialization processes of a plurality of driven members simultaneously. Then, each time the initialization process for each driven member is completed, the interchangeable lens 200 transmits information indicating that fact to the camera body side. By doing so, the camera body can quickly learn which driven members have completed the initialization process, and accordingly can sequentially start the shooting preparation operations on the camera body side, making it possible to further shorten the time until the shooting enabled state is reached.

[0110] The following modifications are also within the scope of the present invention, and it is also possible to combine one or more of the modification examples with the above-described embodiments.

[0111] (Modification Example 1) In each of the above-described embodiments, the driven state transmission unit 222 did not transmit the driven state until the initialization of all the driven members was completed. This may be changed to sequentially transmit the driven state from the driven members whose initialization has been completed. For example, the driven state data 80 may be variable-length data, and only the information regarding the aperture diameter of the aperture 211 may be made transmissible, and after the initialization of the aperture 211 is completed, the transmission of the driven state of the aperture 211 may be started.

[0112] (Modification Example 2) The driven members are not limited to the aperture, focusing lens, and shake correction lens described above. Also, the initialization order of the driven members is not limited to the order shown in each of the above-described embodiments.

[0113] (Modification Example 3) In the interchangeable lens 200 of the above embodiment (FIG. 8), as the driven state information of the driven members that communicate with the camera body side using the hot line communication system, it is configured to transmit the driven state information of a plurality of driven members. However, the present invention is not limited to transmitting the state information of a plurality of driven members, and may be configured to transmit the information indicating the driven state of any one driven member.

[0114] (Modification Example 4) In each of the above embodiments, the interchangeable lens 200 is configured to transmit the initialization status data 60 to the camera body 100 at a first predetermined period using the command data communication system. However, until the initialization process on the interchangeable lens 200 side is completed, a device may be devised to quickly notify the camera body side of the state change of the initialization process. For example, until the initialization process of all the driven members of the interchangeable lens 200 is completed, the communication period of the command data communication system may be configured to be shortened. Specifically, the communication period of the command data communication system on the camera body 100 side and the interchangeable lens 200 side described above may be configured to be controlled to a period shorter than the above-described first predetermined period. Thereby, the camera body 100 can quickly know the completion of the initialization process of each driven member, and the period until shooting preparation and shooting can be shortened.

[0115] (Modification Example 5) In the initialization process 75 of the shake correction lens 210c in each of the above embodiments, the shake correction lens 210c may be configured to perform a process of driving the shake correction lens 210c to a reference position (for example, a process of driving the shake correction lens 210c so that the center position of the shake correction lens 210c coincides with the optical axis center of the photographing lens 200). For example, when the remaining battery level on the camera body side is sufficient, such an origin setting process of the shake correction lens 210c may be added to the initialization process 75.

[0116] (Modification Example 6) In the second embodiment described above, the three initialization processes 73, 75, and 77 are started simultaneously. However, the present invention is not limited to this, and only any two of the initialization processes may be started simultaneously, and the remaining initialization processes may be configured to be started at different timings.

[0117] (Modification Example 7) In the above-described embodiment, every time the state of each initialization process changes (every time the initialization process ends), information indicating that is sent to the camera body side. However, another method is also possible. For example, until all the initialization processes of the driven member to be initialized are completed, the interchangeable lens side is configured to send information indicating that not all the initialization processes have been completed (for example, information indicating that all the initialization processes are incomplete, such as data in which the flags 62 to 63 of the initialization status data 60 in FIG. 6 are all "0"). Then, when the initialization processes of all the driven members are completed, it is configured to send information indicating that (information indicating that all the initialization processes have been completed, specifically, data in which the flags 62 to 63 of the initialization status data 60 in FIG. 6 are all "1"). With such a configuration as well, the interchangeable lens can convey to the camera body that all the initialization processes have been completed when all the initialization processes are completed.

[0118] Unless the features of the present invention are impaired, the present invention is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

Explanation of Signs

[0119] 1... Camera, 100... Camera body, 101... Lens mount, 102... Holding part, 103... Body control part, 117... First communication part on the body side, 118... Second communication part on the body side, 121... Initialization status receiving part, 122... Driven state receiving part, 123... Drive control part, 200... Interchangeable lens, 201... Lens mount, 202... Holding part, 203... Lens control part, 210... Imaging optical system, 210b... Focusing lens, 210c... Shake correction lens, 211... Diaphragm, 212... Focusing lens drive part, 213... Shake correction lens drive part, 214... Diaphragm drive part, 217... First communication part on the lens side, 218... Second communication part on the lens side, 221... Initialization status sending part, 222... Driven state sending part, 223... Initialization control part

Claims

1. A communication method for an interchangeable lens including at least one moving member whose relative position with respect to a camera body changes when attached to the camera body, comprising: receiving from the camera body a request signal requesting information indicating whether initialization of the moving member has been completed; upon receiving the request signal, transmitting to the camera body a signal indicating that initialization has been completed for each initialized moving member; upon transmitting a signal indicating that initialization of the moving member has been completed, starting to transmit information indicating the position of the moving member to the camera body.

2. The communication method according to claim 1, wherein information indicating the position of the moving member for which a signal indicating that initialization has been completed has been transmitted is transmitted.

3. upon transmitting a signal indicating that initialization of the moving member has been completed, starting a request from the camera body for information indicating the position of the moving member, and transmitting in response to the request information indicating the position of the moving member to the camera body; the communication method according to claim 1.

4. The communication method according to claim 1 or 2, wherein information indicating the position of the moving member is periodically transmitted to the camera body.

5. receiving the request signal synchronized with a clock signal of a first frequency; transmitting a signal indicating that initialization of the moving member has been completed synchronized with the clock signal of the first frequency; the communication method according to any one of claims 1 to 3.

6. An interchangeable lens including a moving member whose relative position with respect to a camera body changes when attached to the camera body, comprising: a first communication unit that receives from the camera body a request signal requesting information indicating whether initialization of the moving member has been completed, and upon receiving the request signal, transmits to the camera body a signal indicating that initialization has been completed for each initialized moving member; a second communication unit that, upon transmitting a signal indicating that initialization of the moving member has been completed, starts to transmit information indicating the position of the moving member to the camera body.

7. The interchangeable lens according to claim 6, wherein the second communication unit transmits information indicating the position of some of the moving members among the moving members for which a signal indicating that initialization has been completed has been transmitted.

8. The interchangeable lens according to claim 6 or 7, wherein the first communication unit transmits information indicating the position of the moving member that has transmitted a signal indicating that initialization has been completed.

9. The first communication unit includes a first contact through which a clock signal of a first frequency is transmitted, a second contact through which a signal is transmitted from the camera body to the interchangeable lens in synchronization with the clock signal of the first frequency, and a third contact through which a signal is transmitted from the interchangeable lens to the camera body in synchronization with the clock signal of the first frequency. The interchangeable lens according to any one of claims 6 to 8, wherein the second communication unit includes a fourth contact through which a clock signal of a second frequency is transmitted, and a fifth contact through which a signal is transmitted from the interchangeable lens to the camera body in synchronization with the clock signal of the second frequency.

Images