JP6176346B2 - Lens barrel - Google Patents

Description

  The present invention relates to a lens barrel.

  Digital cameras that can shoot movies are known. Generally, such a digital camera can record audio together with video and store it in a storage medium. For example, Patent Document 1 describes a digital camera that includes a camera body and an interchangeable lens and can shoot a moving image. This interchangeable lens has a driving speed that can drive the diaphragm at a driving sound level that is the same as or lower than the driving sound level of the smaller driving sound generated when the diaphragm is driven at the maximum speed and the minimum speed. Is transmitted to the camera body as a silent speed. This makes it possible to drive the aperture so that the drive sound of the aperture is not recorded when recording is performed, such as during moving image shooting.

JP 2009-288778 A

  The digital camera described in Patent Document 1 has a problem that it can always transmit only the same silent speed information even when the driving sound changes due to a change in temperature.

The invention of claim 1 includes an optical system having a focusing lens, temperature thus changing the movement speed of the focusing lens in the still image shooting, is thus changed to a temperature a moving speed of the focusing lens in the moving image capturing mode In addition, the volume generated by the movement of the focusing lens during movie shooting, the amount of change in shooting magnification per unit time during movie shooting , or the amount of image plane movement per unit time during movie shooting is less than a predetermined value. And a moving section that changes the moving speed of the focusing lens so that

  According to the present invention, the focusing lens can be suitably driven even when the temperature changes.

It is the perspective view which showed the lens-interchangeable camera system to which this invention is applied. It is sectional drawing which showed the lens-interchangeable camera system to which this invention is applied. 2 is a cross-sectional view of a lens barrel 200 showing the arrangement of a temperature sensor 214. FIG. It is a schematic diagram which shows the detail of the holding | maintenance part 102,202. It is a timing chart which shows the example of command data communication. It is a timing chart which shows the example of hotline communication. It is a figure which shows the determination method of the maximum drive speed for moving images.

(First embodiment)
FIG. 1 is a perspective view showing an interchangeable lens type camera system to which the present invention is applied. FIG. 1 shows only devices and apparatuses according to the present invention, and illustration and description of other devices and apparatuses are omitted. The camera 1 includes a camera body 100 and a lens barrel 200 that can be attached to and detached from the camera body 100.

  The camera body 100 is provided with a lens mount 101 to which the lens barrel 200 is detachably attached. At a position near the lens mount 101 of the camera body 100 (inner peripheral side of the lens mount 101), a holding part (electrical connection) that holds a contact in a state of partially protruding toward the inner peripheral side of the lens mount 101 Part) 102 is provided. The holding portion 102 is provided with a plurality of contacts.

  The lens barrel 200 is provided with a lens mount 201 corresponding to the lens mount 101 on the body side, to which the camera body 100 is detachably attached. At a position near the lens mount 201 of the lens barrel 200 (inner peripheral side of the lens mount 201), a holding part (electrical part) that holds the contact in a state of partially protruding toward the inner peripheral side of the lens mount 201. A connecting portion) 202 is provided. The holding portion 202 is provided with a plurality of contacts.

  When the lens barrel 200 is attached to the camera body 100, the holding unit 102 provided with a plurality of contacts is electrically and physically connected to the holding unit 202 provided with a plurality of contacts. Both holders 102 and 202 are used for power supply from the camera body 100 to the lens barrel 200 and transmission / reception of signals between the camera body 100 and the lens barrel 200.

  An imaging element 104 such as a CMOS or CCD is provided behind the lens mount 101 in the camera body 100. Above the camera body 100, a button 105 serving as an input device is provided. The user uses the input device such as the button 105 to instruct the camera body 100 to take a picture, set shooting conditions, and the like.

  FIG. 2 is a cross-sectional view showing an interchangeable lens type camera system to which the present invention is applied. The lens barrel 200 includes an imaging optical system 210 that forms a subject image. The imaging optical system 210 includes a plurality of lenses 210 a to 210 c and a diaphragm 211. The 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.

  Inside the lens barrel 200, a lens control unit 203 that controls each part of the lens barrel 200 is provided. The lens control unit 203 includes a microcomputer (not shown) and its peripheral circuits. The lens control unit 203 is connected to a lens side first communication unit 217, a lens side second communication unit 218, a focusing lens driving unit 212, a temperature sensor 214, a ROM 215, and a RAM 216.

  The lens-side first communication unit 217 and the lens-side second communication unit 218 transmit and receive signals to and from the camera body 100 via the communication contacts of the holding units 102 and 202. Each of the lens side first communication unit 217 and the lens side second communication unit 218 is a communication interface on the lens barrel 200 side. The lens control unit 203 performs communication (hotline communication, command data communication) described later with the camera body 100 (body control unit 103 described later) using these communication interfaces.

  The focusing lens driving unit 212 includes a motor (for example, an actuator such as a stepping motor) that generates a driving force and a transmission system (for example, a combination of a plurality of gears) that transmits the driving force to the focusing lens 210b. . The focusing lens driving unit 212 drives the focusing lens 210b in the optical axis direction at a driving speed corresponding to the driving signal received from the camera body 100. In addition to the above, the lens barrel 200 includes a drive unit that drives the shake correction lens 210c and a drive unit that drives the diaphragm 211, but these drive units are not shown in FIG.

  The temperature sensor 214 is a sensor that detects the temperature of the lens barrel 200 and outputs a temperature signal. The ROM 215 is a non-volatile storage medium, and stores in advance a predetermined control program executed by the lens control unit 203, a maximum driving speed and an acceleration / deceleration of a focusing lens 210b described later. The RAM 216 is a volatile storage medium and is used as a storage area for various data by the lens control unit 203.

  A shutter 115 for controlling the exposure state of the image sensor 104 and an optical filter 116 combining an optical low-pass filter and an infrared cut filter are provided on the front surface of the image sensor 104. The subject light that has passed through the imaging optical system 210 enters the image sensor 104 via the shutter 115 and the filter 116.

  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 includes a microcomputer (not shown), a RAM, and peripheral circuits thereof.

  A body-side first communication unit 117 and a body-side second communication unit 118 are connected to the body control unit 103. The body-side first communication unit 117 is connected to the holding unit 102, and can transmit and receive signals to and from the lens-side first communication unit 217 through a plurality of contacts provided on the holding unit 102. Similarly, the body side second communication unit 118 can transmit and receive signals to and from the lens side second communication unit 218. In other words, each of the body-side first communication unit 117 and the body-side second communication unit 118 is a body-side communication interface. The body control unit 103 performs communication (hotline communication and command data communication) to be described later with the lens barrel 200 (lens control unit 203) using these communication interfaces.

  A display device 111 configured by an LCD panel or the like is disposed on the back surface of the camera body 100. The body control unit 103 displays various menu screens for setting an image of a subject (a so-called through image) based on the output of the image sensor 104, shooting conditions, and the like on the display device 111.

  The camera body 100 has two types of shooting modes, a still image shooting mode for shooting a still image and a moving image shooting mode for shooting a moving image. When the user instructs the camera body 100 to set these shooting modes, the body control unit 103 starts an operation in the shooting mode. The camera body 100 includes a microphone (not shown), and audio input to the microphone is stored in a storage medium (not shown) together with a video during moving image shooting.

(Explanation of automatic focus adjustment)
The body control unit 103 is configured to execute a well-known automatic focus adjustment process. In this automatic focus adjustment process, the body control unit 103 is configured to be able to selectively use two types of focus detection processes. Specifically, the body control unit 103 can selectively use a so-called imaging surface phase difference detection focus detection process and a so-called contrast detection focus detection process. The body control unit 103 uses these two types of focus detection processing properly depending on the shooting situation, the characteristics of the subject, and the like.

  The focus detection process of the imaging surface phase difference detection method by the body control unit 103 will be described. The image sensor 104 of the present embodiment has focus detection pixels (referred to as focus detection pixels). The focus detection pixels are the same as those described in Japanese Patent Application Laid-Open No. 2007-317951. The body control unit 103 performs focus detection processing by performing a known phase difference detection calculation using pixel output data from the focus detection pixels. The phase difference detection calculation is the same as that described in, for example, Japanese Patent Application Laid-Open No. 2007-317951, and thus the description thereof is omitted. The body control unit 103 performs automatic focus adjustment by causing the focusing lens driving unit 212 to drive the focusing lens 210b based on the defocus amount obtained by the focus detection processing.

  The contrast detection focus detection process by the body control unit 103 will be described. The body control unit 103 performs a known contrast detection calculation using pixel output data from the imaging pixels included in the imaging element 104. The body control unit 103 performs this contrast detection calculation while driving the focusing lens 210b between the closest drive limit position and the infinity drive limit position, and the focusing evaluation value (contrast value) reaches a peak. Automatic focus adjustment is performed by detecting the position of the lens 210b.

(Description of temperature sensor 214)
FIG. 3 is a sectional view of the lens barrel 200 showing the arrangement of the temperature sensor 214. The left side of FIG. 3 is the subject direction, and the right side of FIG. 3 is the camera body 100 direction. In the lens barrel 200, a main substrate 242 on which the lens control unit 203 and the like are disposed is provided. The shake correction lens 210c is fixed to the shake correction substrate 241 with a spring or the like. On the shake correction substrate 241, a voice coil motor (not shown) for driving the shake correction lens 210c, a sensor (not shown) for detecting the position of the shake correction lens 210c, and the like are arranged. The shake correction board 241 and the main board 242 are electrically connected by a flexible cable 243. In the present embodiment, the temperature sensor 214 is mounted on the surface of the main board 242 on the camera body 100 side.

  Note that the temperature sensor 214 may be mounted on the surface of the flexible cable 243 as indicated by a broken line in FIG. Further, the temperature sensor 214 may be arranged at a location different from these positions.

(Description of holding units 102 and 202)
FIG. 4 is a schematic diagram showing details of the holding units 102 and 202. In FIG. 4, 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 disposed at a location deeper than the mount surface of the lens mount 101 of the camera body 100 (a location on the right side of the lens mount 101 in FIG. 4). Similarly, the holding unit 202 is arranged on the right side of the lens mount 201 because the holding unit 202 of the present embodiment is arranged at a position protruding from the mount surface of the lens mount 201 of the lens barrel 200. Represents. Since the holding unit 102 and the holding unit 202 are arranged in this way, when the mount surface of the lens mount 101 and the mount surface of the lens mount 201 are brought into contact with each other, the camera body 100 and the lens barrel 200 are mounted and coupled. The holding part 102 and the holding part 202 are connected, and the electrical contacts provided on both holding parts are also connected. Since such a mount structure is well known, further explanation and illustration are omitted.

  As shown in FIG. 4, the holding unit 102 has 12 contacts BP <b> 1 to BP <b> 12. The holding unit 202 has twelve contacts LP1 to LP12 corresponding to the twelve contacts described above.

  The contacts BP1 and BP2 are connected to the first power supply circuit 130 in the camera body 100. The first power supply circuit 130 supplies an operating voltage of each part in the lens barrel 200 excluding a circuit (such as the focusing lens driving unit 212) having a driving system such as an actuator to the contact point BP1 and having relatively large power consumption. That is, the operating voltage of each part in the lens barrel 200 excluding the above driving parts is supplied from the contact BP1 and the contact LP1. The voltage value that can be supplied to the contact point BP1 has a range between the minimum voltage value and the maximum voltage value (for example, a voltage width in the 3V range). The voltage value that is normally supplied is the maximum voltage value and the minimum voltage value. Is a voltage value in the vicinity of the intermediate value. Thus, the current value supplied from the camera body 100 side to the lens barrel 200 side is a current value within a range of about several tens mA to several hundred mA in the power-on state.

  The contact BP2 is a ground terminal corresponding to the operating voltage given to the contact BP1. That is, the contact BP2 and the contact LP2 are ground terminal voltages corresponding to the above operating voltage.

  In the following description, the signal line constituted by the contact point BP1 and the contact point LP1 is referred to as a signal line V33. A signal line constituted by the contact point BP2 and the contact point LP2 is referred to as a signal line GND. These contacts LP1, LP2, BP1, BP2 constitute a power supply system contact for supplying power from the camera body 100 side to the lens barrel 200 side.

  The contacts BP3, BP4, BP5, and BP6 are connected to the body-side first communication unit 117. The contact points LP3, LP4, LP5, and LP6 on the lens barrel 200 side corresponding to these contact points 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 transmit and receive signals to and from each other using these contacts (communication system contacts). The contents of communication performed by the body-side first communication unit 117 and the lens-side first communication unit 217 will be described in detail later.

  In the following description, a signal line constituted by the contact BP3 and the contact LP3 is referred to as a signal line CLK. Similarly, the signal line constituted by the contact BP4 and the contact LP4 is signal line BDAT, the signal line constituted by the contact BP5 and the contact LP5 is signal line LDAT, and the signal line constituted by the contact BP6 and the contact LP6 is signaled. Called line RDY.

  The contacts BP7, BP8, BP9, and BP10 are connected to the body-side second communication unit 118. The contact points LP7, LP8, LP9, and LP10 on the lens barrel 200 side corresponding to these contact points are connected to the lens-side second communication unit 218. The lens-side second communication unit 218 transmits signals to the body-side second communication unit 118 using these contacts (communication system contacts). The contents of communication performed by the body-side second communication unit 118 and the lens-side second communication unit 218 will be described in detail later.

  In the following description, a signal line constituted by the contact BP7 and the contact LP7 is referred to as a signal line HREQ. Similarly, a signal line composed of the contact point BP8 and the contact point LP8 is signal line HANS, a signal line composed of the contact point BP9 and the contact point LP9 is signal line HCLK, and a signal line composed of the contact point BP10 and the contact point LP10 is signaled. Called line HDAT.

  The contact BP11 and the contact BP12 are connected to the second power supply circuit 131 in the camera body 100. The second power supply circuit 131 supplies a driving voltage of a circuit (such as the focusing lens driving unit 212) having a driving system such as an actuator and a relatively large power consumption to the contact point BP12. That is, the driving voltage of the focusing lens driving unit 212 is supplied from the contact point BP12 and the contact point LP12. The voltage value that can be supplied to the contact point BP12 has a range from the minimum voltage value to the maximum voltage value, all of which are larger than the voltage value range that can be supplied to the contact point BP1 (for example, The maximum voltage value that can be supplied to the contact point BP12 is 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 whose magnitude is different from the voltage value supplied to the contact point BP1. The voltage value that is normally supplied to the contact BP12 is a voltage value in the vicinity of an intermediate value between the maximum voltage value and the minimum voltage value that can be supplied to the contact BP12. As a result, the current supplied from the camera body 100 side to the lens barrel 200 side has a current value of about 10 mA to several A in the power-on state.

  The contact BP11 is a ground terminal corresponding to the drive voltage given to the contact BP12. That is, the contact BP11 and the contact LP11 are ground terminals corresponding to the drive voltage.

  In the following description, a signal line constituted by the contact BP11 and the contact LP11 is referred to as a signal line PGND. A signal line constituted by the contact BP12 and the contact LP12 is referred to as a signal line BAT. These contacts LP11, LP12, BP11, BP12 constitute a power supply system contact for supplying power from the camera body 100 side to the lens barrel 200 side.

  As is apparent from the magnitude relationship between the voltage value (current value) supplied to the contacts BP12 and LP12 and the voltage value (current value) supplied to the contacts BP1 and LP1, the voltages are supplied to the contacts. The difference between the maximum value and the minimum value of the current flowing through the contact point BP11 and the contact point LP11 serving as the ground terminals for each of the voltages is larger than the difference between the maximum value and the minimum value of the current flowing through the contact points BP2 and LP2. ing. 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 in the lens barrel 200, and it is not necessary to drive the driven member. In some cases, each drive unit does not consume power.

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

  In the present embodiment, 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”. A transmission line composed of four signal lines (signal lines CLK, BDAT, LDAT, and RDY) used for command data communication is referred to as a first transmission line.

  FIG. 5 is a timing chart showing an example of command data communication. The body control unit 103 and the body-side first communication unit 117 first check the signal level of the signal line RDY at the start of command data communication (T1). The signal level of the signal line RDY indicates whether the lens-side first communication unit 217 can communicate. The lens control unit 203 and the lens-side first communication unit 217 output a signal of H (High) level from the contact LP6 when communication is not possible. That is, the signal level of the signal line RDY is set to H level. When the signal line RDY is at the H level, the body control unit 103 and the body-side first communication unit 117 do not start communication until the signal line RDY is at the L level. Also, the next processing during communication is not executed.

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

  When the clock signal 401 is output to the signal line CLK, the lens control unit 203 and the lens-side first communication unit 217 synchronize with the clock signal 401, and the lens-side command packet that is the first half of the response data from the contact LP5. The signal 403 is output. That is, the lens-side command packet signal 403 is transmitted to the first body-side communication unit 117 via the signal line LDAT.

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

  When the first control process 404 is completed, the lens control unit 203 notifies the lens side first communication unit 217 of the completion of the first control process 404. In response to this notification, the lens side first communication unit 217 outputs an L level signal from the contact LP6. That is, the signal level of the signal line RDY is set to L level (T3). The body control unit 103 and the first body side communication unit 117 output the clock signal 405 from the contact point BP3 in accordance with the change in the signal level. That is, the clock signal 405 is transmitted to the lens side first 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 data packet signal 406 that is the latter half of the control data from the contact point BP4 in synchronization with the clock signal 405. That is, the body side data packet signal 406 is transmitted to the lens side first communication unit 217 via the signal line BDAT.

  Further, when the clock signal 405 is output to the signal line CLK, the lens control unit 203 and the lens side first communication unit 217 synchronize with the clock signal 405, and the lens which is the latter half of the response data from the contact LP5 receives the data packet signal. 407 is output. That is, the lens-side data packet signal 407 is transmitted to the first body-side communication unit 117 via the signal line LDAT.

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

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

  For example, a case where the received body side command packet signal 402 is a content requesting specific data on the lens barrel side will be described. As the 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 the first control process 404, the lens control unit 203 uses the checksum data included in the command packet signal 402 to easily determine whether there is an error in the communication of the command packet signal 402 from the number of data bytes. The communication error check process to check is also executed. The specific data signal generated in the 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 the communication error check process as described above using the checksum data included in the body side data packet signal 406 as the second control process 408.

  For example, a case where the received body-side command packet signal 402 is an instruction to drive a lens-side driven member will be described. For example, a case where 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 will be described. As the first control process 404, the lens control unit 203 analyzes the content of the command packet signal 402 and generates an acknowledgment signal indicating that the content has been understood. Furthermore, the lens control unit 203 also executes the communication error check process as described above using the checksum data included in the command packet signal 402 as the first control process 404. The acknowledge signal generated in the first control process 404 is output to the body side as a lens side data packet signal 407. In addition, as the second control process 408, the lens control unit 203 executes an analysis process of the contents of the body side data packet signal 406 and uses the checksum data included in the body side data packet signal 406 as described above. Execute the check process.

  When the second control process 408 is completed, the lens control unit 203 notifies the lens side first communication unit 217 of the completion of the second control process 408. Accordingly, the lens control unit 203 causes the lens side first communication unit 217 to output an L level signal from the contact LP6. That is, the signal level of the signal line RDY is set to L level (T5).

  If the received body-side command packet signal 402 is an instruction to drive a lens-side driven member (for example, a focusing lens) as described above, the lens control unit 203 sends a signal to the lens-side first communication unit 217. While the signal level of the line RDY is set to L level, the focusing lens driving unit 212 is caused to execute processing for driving the focusing lens 210b by the driving amount.

  The communication performed at the above-described time T1 to time T5 is one command data communication. As described above, in one command data communication, body control unit 103 and body side first communication unit 117 transmit body side command packet signal 402 and body side data packet signal 406 one by one. In other words, the body side command packet signal 402 and the body side data packet signal 406 together constitute one control data although it is divided and transmitted for convenience of processing.

  Similarly, in one command data communication, the lens control unit 203 and the lens side first communication unit 217 transmit the lens side command packet signal 403 and the lens side data packet signal 407 one by one. That is, the lens side command packet signal 403 and the lens side data packet signal 407 are combined to form one response data.

  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. And do it. The contact LP6 and the contact BP6 used for command data communication are contacts through which asynchronous signals (signal level of the signal line RDY / H (High) level or L (Low) level) that are not synchronized with other clock signals are transmitted. is there.

(Description 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. Send. Hereinafter, details of communication performed between the lens-side second communication unit 218 and the body-side second communication unit 118 will be described.

  In the present embodiment, communication performed between the lens control unit 203 and the lens-side second communication unit 218, and the body control unit 103 and the body-side second communication unit 118 is referred to as “hotline communication”. A transmission line composed of four signal lines (signal lines HREQ, HANS, HCLK, and HDAT) used for hot line communication is referred to as a second transmission line.

  FIG. 6 is a timing chart showing an example of hotline communication. The body control unit 103 of the present embodiment is configured to start hot line communication every second predetermined period (for example, 1 millisecond in the present embodiment). This period is shorter than the period for performing command data communication. FIG. 6A is a diagram illustrating a state in which hotline communication is repeatedly performed at predetermined intervals Tn. FIG. 6B shows a state in which a certain communication period Tx is expanded in the hot line communication repeatedly executed. Hereinafter, the procedure of hotline communication will be described based on the timing chart of FIG.

  At the start of hot line communication (T6), body control unit 103 and body-side second communication unit 118 first output an L level signal from contact point BP7. That is, the signal level of the signal line HREQ is set to L level. The lens side second communication unit 218 notifies the lens control unit 203 that this signal has been input to the contact LP7. In response to this notification, the lens control unit 203 starts executing a generation process 501 that generates 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.

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

  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 in synchronization with the clock signal 502. That is, the lens position data signal 503 is transmitted to the body-side second communication unit 118 via the signal line HDAT.

  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 an H level signal from the contact LP8. That is, the signal level of the signal line HANS is set to the H level (T8). The body-side second communication unit 118 outputs an H-level signal from the contact LP7 in response to the input of this signal to the contact BP8. That is, the signal level of the signal line HREQ is set to H level (T9).

  The communication performed from time T6 to time T9 described above is one hot line communication. As described above, in one hot line 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 (signal level HREQ signal level / H (High) level or L (Low) level) are transmitted, and the contacts LP8 and BP8 are asynchronous signals (signal line HANS). Signal level / H (High) level or L (Low) level).

  Note that the command data communication and the hotline communication can be executed simultaneously or partially in parallel. That is, 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. is there.

(Description of driving speed of focusing lens 210b)
In this camera system, the body control unit 103 determines the driving speed of the focusing lens 210b. When the body control unit 103 transmits a driving signal including the driving speed of the focusing lens 210b to the lens control unit 203 (focusing lens driving unit 212), the focusing lens driving unit 212 drives the focusing lens 210b at the driving speed. In order to perform such an operation, the body control unit 103 needs to know how fast the focusing lens driving unit 212 can drive the focusing lens 210b.

  Therefore, the lens control unit 203 sets the maximum driving speed of the focusing lens 210b suitable for still image shooting (hereinafter referred to as the maximum driving speed for still images) and the maximum driving speed of the focusing lens 210b suitable for moving image shooting (hereinafter referred to as moving images). For example) is transmitted to the body control unit 103 by hot line communication every predetermined period (for example, 16 milliseconds).

  During still image shooting, no problem occurs even if the focusing lens 210b is driven at high speed. Therefore, the maximum driving speed for still images in this embodiment is the maximum driving speed determined by the motor and transmission system of the focusing lens driving unit 212. In other words, the maximum still image driving speed in the present embodiment is a speed that represents the limit of the driving capability of the focusing lens driving unit 212.

  On the other hand, when performing moving image shooting, the focusing lens 210b must be driven with attention to the following points from the viewpoint of recorded moving image quality. First, the higher the driving speed of the focusing lens 210b, the greater the drive sound generated by the motor and drive system. When such a drive sound is picked up by a microphone, it becomes noise. Next, if the image magnification due to the driving of the focusing lens 210b is too large, a change in the angle of view unintended by the user occurs and the appearance is impaired. Such image magnification is particularly remarkable in a varifocal lens. Finally, if the change in the amount of blur due to the driving of the focusing lens 210b is too steep, the moving image viewer feels confused. Therefore, it is desirable that the focus is moved slowly to some extent. From this point, the maximum moving image driving speed in the present embodiment is set to be slower than the limit of the driving capability of the focusing lens driving unit 212. Hereinafter, a method for determining the maximum driving speed for moving images will be described.

  FIG. 7 is a diagram showing a method for determining the maximum drive speed for moving images. FIG. 7A is a graph showing the relationship between the lens driving speed and the generated driving volume. In the present embodiment, the moving image maximum driving speed is determined so that the driving sound volume is less than a predetermined amount. FIG. 7B is a graph showing the relationship between the lens driving speed and the photographing magnification change rate (the photographing magnification change amount per unit time). In the present embodiment, the maximum moving image driving speed is determined so that the rate of change in shooting magnification is less than a predetermined amount (for example, 5% per second). FIG. 7C is a graph showing the relationship between the lens driving speed and the image plane moving speed (image plane moving amount per unit time). In the present embodiment, the moving image maximum drive speed is determined so that the image plane moving speed is less than a predetermined amount (for example, twice the depth of focus per second).

  That is, the maximum driving speed for moving images in the present embodiment is the maximum that the driving volume, the amount of change in photographing magnification per unit time, and the amount of image plane movement per unit time are less than a predetermined threshold value. Driving speed.

  By the way, the limit of the driving capability of the focusing lens driving unit 212, the above-described driving sound volume, and the like vary depending on the temperature of the motor. For example, the lower the temperature, the lower the driving capability of the motor. Therefore, in this embodiment, the maximum driving speed for still images and the maximum driving speed for moving images determined as described above are stored in the ROM 215 as a table for each predetermined temperature range. For example, the maximum driving speed for still images and moving images when the temperature is 10 degrees Celsius or more and less than 15 degrees Celsius, the maximum driving speed for still images and the maximum driving speed for moving images when the temperature is 15 degrees Celsius or more and less than 20 degrees Celsius, Etc. are stored in the ROM 215. Note that the maximum still image driving speed and the maximum moving image driving speed stored in the ROM 215 are smaller as the temperature detected by the temperature sensor 214 is lower.

  The lens control unit 203 reads the maximum driving speed for still images and the maximum driving speed for moving images corresponding to the temperature detected by the temperature sensor 214 from the table stored in the ROM 215 and transmits them to the camera body 100. . That is, the lens control unit 203 changes the maximum still image driving speed and the maximum moving image driving speed transmitted to the camera body 100 in accordance with the temperature signal output from the temperature sensor 214.

  The body control unit 103 transmits a driving signal for the focusing lens 210b to the lens control unit 203 based on the still image maximum driving speed and the moving image maximum driving speed transmitted by the lens control unit 203. The drive signal includes a predetermined identifier indicating that the signal is a drive signal for the focusing lens 210b, a drive amount and a drive direction of the focusing lens 210b, and a drive speed of the focusing lens 210b.

  The body control unit 103 instructs driving of the focusing lens 210b at the maximum driving speed for still images in the still image shooting mode, and drives the focusing lens 210b at the maximum driving speed for moving images in the moving image shooting mode. Instruct. Note that the body control unit 103 does not always drive the focusing lens 210b at the maximum speed. For example, the focusing lens 210b may be driven at a speed slower than the above-mentioned maximum speed when performing automatic focus adjustment while tracking a moving object or during a search operation when performing so-called contrast AF. However, even in such a case, the focusing lens 210b is not driven at a speed exceeding the maximum speed transmitted from the lens barrel 200.

(Description of acceleration / deceleration control of focusing lens 210b)
The driving sound volume of the focusing lens 210b described above changes depending on the acceleration and deceleration. Therefore, in the present embodiment, four data relating to acceleration / deceleration are stored in the ROM 215 in advance. The four data are the acceleration of the focusing lens 210b suitable for still image shooting, the deceleration of the focusing lens 210b suitable for still image shooting, the acceleration of the focusing lens 210b suitable for moving image shooting, and the suitable for movie shooting. This is the deceleration of the focusing lens 210b. Hereinafter, these data will be described.

  The acceleration and deceleration suitable for still image shooting are values representing the limit of the driving capability of the focusing lens driving unit 212, like the maximum driving speed for still images. On the other hand, the acceleration and deceleration suitable for moving image shooting are set lower than in the case of still image shooting in consideration of the driving volume.

  The body control unit 103 transmits data representing the current shooting mode (still image shooting mode or moving image shooting mode) to the lens control unit 203 by command data communication when the power is turned on or when the shooting mode is changed. By receiving this data, the lens control unit 203 always grasps the current shooting mode. When a drive signal is transmitted from the body control unit 103, the acceleration and deceleration of the focusing lens 210b are switched according to the current shooting mode.

  Specifically, when the drive signal is transmitted, the lens control unit 203 first determines whether the camera body 100 is operating in the still image shooting mode or the moving image shooting mode. When it is determined that the camera is operating in the still image shooting mode, the focusing lens driving unit 212 drives the focusing lens 210b based on acceleration and deceleration suitable for still image shooting. On the other hand, when it is determined that the camera is operating in the moving image shooting mode, the focusing lens driving unit 212 drives the focusing lens 210b based on acceleration and deceleration suitable for moving image shooting.

  The reason why acceleration and deceleration are separately stored in the ROM 215 is that the characteristics of the driving volume during acceleration and the characteristics of the driving volume during deceleration may be different. For example, there is a case where acceleration needs to be performed slowly, but there is no problem even if deceleration is rapid.

According to the camera system according to the first embodiment described above, the following operational effects can be obtained.
(1) The focusing lens driving unit 212 drives the focusing lens 210b at a driving speed according to the driving signal received from the camera body 100 via the lens-side first communication unit 217. The lens barrel 200 is provided with a temperature sensor 214 that detects the temperature of the lens barrel 200 and outputs a temperature signal. The lens control unit 203 controls the lens-side first communication unit 217 so as to transmit the still image maximum driving speed and the moving image maximum driving speed to the camera body 100. The lens control unit 203 changes the maximum still image driving speed and the maximum moving image driving speed transmitted to the camera body 100 in accordance with the temperature signal output from the temperature sensor 214. Since it did in this way, even if it is a case where a drive sound changes with the change of temperature, it becomes possible to change the drive speed of a lens appropriately.

(2) The focusing lens driving unit 212 includes a motor that generates a driving force and a transmission system that transmits the driving force to the focusing lens. The maximum drive speed for still images is the maximum drive speed determined by the motor and transmission system, and the maximum drive speed for moving images is the drive volume, the amount of change in shooting magnification per unit time, and the amount of image plane movement per unit time. The maximum driving speed is set to be less than a predetermined threshold value. Since it did in this way, even if it is a case where automatic focus adjustment is performed during moving image shooting, an appropriate shooting result can be obtained.

(3) The lens control unit 203 decreases the maximum still image driving speed and the maximum moving image driving speed transmitted to the camera body 100 as the temperature detected by the temperature sensor 214 is lower. Since it did in this way, even if it is a case where the drive capability of the focusing lens 210b falls under a low temperature environment, the focusing lens 210b can be appropriately controlled from the camera body 100. FIG.

(4) The ROM 215 stores the acceleration and deceleration of the focusing lens 210b suitable for still image shooting and the acceleration and deceleration of the focusing lens 210b suitable for moving image shooting. The lens control unit 203 determines whether the camera body 100 is operating in a still image capturing mode for capturing a still image or a moving image capturing mode for capturing a moving image. When it is determined that the camera body 100 is operating in the still image shooting mode, the focusing lens driving unit 212 drives the focusing lens 210b based on acceleration and deceleration suitable for still image shooting, and the camera body 100 Is determined to be operating in the moving image shooting mode, the focusing lens 210b is driven based on acceleration and deceleration suitable for moving image shooting. Since it did in this way, the appropriate lens drive which considered the drive volume during acceleration / deceleration can be performed.

(5) The drive signal transmitted from the body control unit 103 to the lens barrel 200 includes the drive amount, the drive direction, and the drive speed of the focusing lens 210b. Since it did in this way, it becomes possible to designate an appropriate drive speed whenever the focusing lens 210b is driven.

(Second Embodiment)
The camera system according to the second embodiment has the same configuration as the camera system according to the first embodiment. In addition, the same code | symbol is attached | subjected about the location similar to the digital camera which concerns on 1st Embodiment, and description is abbreviate | omitted.

  In the camera system according to the second embodiment, when the lens control unit 203 transmits the maximum driving speed for still images and the maximum driving speed for moving images to the camera body 100, these data are stored in the ROM 215 together with these data. Each acceleration / deceleration is also transmitted to the camera body 100. That is, the lens control unit 203 according to the present embodiment performs the maximum driving speed for still images, the maximum driving speed for moving images, and the acceleration and reduction of the focusing lens 210b suitable for still image shooting every predetermined period (for example, 16 milliseconds). The speed and the acceleration and deceleration of the focusing lens 210b suitable for moving image shooting are transmitted to the camera body 100 (body control unit 103).

  Based on the acceleration and deceleration received from the lens control unit 203, the body control unit 103 transmits a drive signal including the acceleration and deceleration to the lens barrel 200 (lens control unit 203). The focusing lens driving unit 212 drives the focusing lens 210b based on the driving speed and acceleration / deceleration designated by the body control unit 103. That is, in this embodiment, the lens control unit 203 does not determine the still image shooting mode and the moving image shooting mode, but the body control unit 103 determines the still image shooting mode and the moving image shooting mode. Therefore, in this embodiment, it is not necessary to transmit the shooting mode of the camera body 100 from the body control unit 103 to the lens barrel 200.

According to the camera system according to the second embodiment described above, the following operational effects can be obtained.
(1) The lens control unit 203 adds the acceleration and deceleration of the focusing lens 210b suitable for still image shooting and the focusing lens 210b suitable for moving image shooting in addition to the maximum driving speed for still images and the maximum driving speed for moving images. The lens-side first communication unit 217 is controlled to transmit the acceleration and deceleration to the camera body 100. Further, the drive signal transmitted from the camera body 100 includes the acceleration and deceleration of the focusing lens 210b. Since it did in this way, the flexible control of an acceleration and a deceleration is attained from the camera body 100 side.

(Third embodiment)
The camera system according to the third embodiment has the same configuration as the camera system according to the first embodiment. In addition, the same code | symbol is attached | subjected about the location similar to the digital camera which concerns on 1st Embodiment, and description is abbreviate | omitted.

  If the temperature detected by the temperature sensor 214 is constant, the maximum still image driving speed and the maximum moving image driving speed are also constant. Therefore, in such a case, it is not necessary to repeatedly transmit the maximum driving speed for still images and the maximum driving speed for moving images from the lens control unit 203. Therefore, the lens control unit 203 according to the present embodiment does not periodically transmit each driving speed, but transmits each driving speed only when the temperature of the lens barrel 200 detected by the temperature sensor 214 changes. To do.

  That is, the lens control unit 203 of the present embodiment transmits the still image maximum driving speed and the moving image maximum driving speed to the camera body 100 in response to a change in the temperature detected by the temperature sensor 214.

According to the camera system of the third embodiment described above, the following operational effects can be obtained.
(1) The lens control unit 203 transmits the still image maximum driving speed and the moving image maximum driving speed to the camera body 100 in response to the change in the temperature detected by the temperature sensor 214. The communication unit 217 was controlled. Since it did in this way, the communication amount when the temperature is not changing is reduced.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
In each of the embodiments described above, the maximum driving speed for moving images is the maximum at which the driving volume, the amount of change in photographing magnification per unit time, and the amount of image plane movement per unit time are less than a predetermined threshold. The drive speed was set. In other words, the smallest drive among the maximum drive speed in consideration of the drive volume, the maximum drive speed in consideration of the imaging magnification change rate, and the maximum drive speed in consideration of the image plane moving speed. The speed is transmitted to the camera body 100 as the maximum driving speed for moving images. Alternatively, all these three driving speeds may be transmitted to the camera body 100. By doing so, the camera body 100 can select the most suitable maximum drive speed from the three maximum drive speeds received from the lens barrel 200 according to the situation.

(Modification 2)
In each of the embodiments described above, the temperature sensor 214 detects the temperature of the lens barrel and outputs a temperature signal. Alternatively, the temperature outside the lens barrel may be detected. In this case, the lens control unit 203, together with the temperature signal output from the temperature sensor 214, operates the heating member (for example, the focusing lens driving unit 212) existing in the lens barrel (for example, focusing by the focusing lens driving unit 212). The maximum driving speed for still images and the maximum driving speed for moving images transmitted to the camera body 100 may be changed on the basis of the total driving time, the total driving distance, and the energization time of the lens 210b. In other words, the lens control unit 203 estimates the temperature inside the lens barrel from the temperature outside the lens barrel and the operating status of the focusing lens driving unit 212, and based on the estimated temperature, the maximum for still image The driving speed and the maximum driving speed for moving images may be changed. This eliminates the need to install the temperature sensor 214 inside the lens barrel, thereby reducing the space required inside the lens barrel, reducing the size of the lens barrel, and manufacturing the lens barrel. Simplification can be performed.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, 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. .

DESCRIPTION OF SYMBOLS 1 ... Camera, 100 ... Camera body, 101 ... Lens mount, 102 ... Holding part, 103 ... Body control part, 117 ... Body side 1st communication part, 118 ... Body side 2nd communication part, 200 ... Lens barrel, 201 DESCRIPTION OF SYMBOLS ... Lens mount, 202 ... Holding part, 203 ... Lens control part, 210 ... Imaging optical system, 210b ... Focusing lens, 212 ... Focusing lens drive part, 214 ... Temperature sensor, 215 ... ROM, 217 ... Lens side 1st communication , 218... Lens side second communication unit

Claims (8)

An optical system having a focusing lens;
Temperature thus changing the movement speed of the focusing lens in the still image shooting, with is thus changed to a temperature a moving speed of the focusing lens in the moving image capturing mode, the focusing lens during movie shooting is generated by moving the volume Or a moving unit that changes a moving speed of the focusing lens so that an imaging magnification change amount per unit time during moving image shooting or an image plane moving amount per unit time during moving image shooting is less than a predetermined value, respectively.
A lens barrel comprising: The lens barrel according to claim 1,
The moving unit changes the limit of the moving speed of the focusing lens in the moving image shooting mode according to the temperature, and the sound volume or the change amount of the shooting magnification or the image plane during moving image shooting within the limit of the moving speed of the focusing lens. A lens barrel that changes a moving speed of the focusing lens such that the moving amount is less than a predetermined value. In the lens barrel according to claim 1 or 2 ,
It has a temperature detector that detects the temperature,
The moving unit is a lens barrel that changes a moving speed of the focusing lens based on a detection result by the temperature detecting unit. In the lens barrel according to any one of claims 1 to 3 ,
The moving unit is a lens barrel that decreases the moving speed of the focusing lens as the temperature decreases. In the lens barrel according to any one of claims 1 to 4,
A lens barrel provided with a storage unit for recording information relating to a moving speed of the focusing lens. In the lens barrel according to any one of claims 1 to 5 ,
It has a communication unit that can communicate with the camera body,
The communication unit includes a lens barrel for transmitting information about the moving speed of the focusing lens to the camera body. In the lens barrel according to any one of claims 1 to 6 ,
The moving unit includes a motor that generates a force for moving the focusing lens, and a transmission system that transmits the force generated by the motor to the focusing lens, and the moving speed of the focusing lens is transmitted to the motor and the transmission system. Lens barrel defined by In the lens barrel according to any one of claims 1 to 7 ,
The moving unit is a lens barrel that moves the focusing lens with acceleration or deceleration of the focusing lens in still image shooting and acceleration or deceleration of the focusing lens in moving image shooting.

Images