JP2010237514A - Imaging apparatus and imaging lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which reduces the time to wait for data transfer by transmitting large-volume lens data in a high-speed communication state, and to provide an imaging lens. <P>SOLUTION: In a low-speed mode, a data output terminal A and a data input terminal B are connected to a transmission line 33b by switches 42 and 43, and state data is transmitted/received. In a high-speed mode, the transmission line 33b connects only a data output terminal B and a data input terminal A, and a transmission line 34a connects only the data output terminal A and the data input terminal B by the switches 42 and 43, and full duplex communication is performed between a camera body 100 and the imaging lens 200. Body data is transmitted from the camera body 100, and the lens data is transmitted from the imaging lens 200 by the full duplex communication. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging apparatus to which a photographic lens can be detachably attached, and more particularly to an imaging apparatus that transmits and receives data to and from the photographic lens.

  In a camera using an interchangeable photographic lens, various data such as data specific to the photographic lens and data for controlling the photographic lens are transferred between the photographic lens and the camera. In order to transfer these various data more appropriately, there is a technique for switching a plurality of communication states depending on the situation. In Patent Document 1, an initial communication mode for communicating lens-specific information is selected immediately after power-on to the camera body and immediately after an interchangeable lens unit is mounted, and information for lens control is communicated after completion of the initial communication mode. An imaging apparatus that selects a control communication mode is disclosed.

JP-A-9-33793

  In the imaging device disclosed in Patent Document 1, the only difference between the two communication modes that are switched according to the data to be transmitted is that the communication data to be prepared is different, and there is no difference in communication methods such as communication path and communication speed. No. For this reason, if the amount of prepared communication data is large, more communication time is required.

According to the first aspect of the present invention, a photographic lens capable of outputting lens data, which is fixed data determined for each photographic lens, and state data representing the state of the photographic lens can be detachably attached. A communication unit that operates by switching between an attachment unit, a first communication mode, and a second communication mode that is different from the first communication mode, and transmits and receives data to and from the photographing lens; Control means for performing control based on the lens data and the state data received by the communication means, and the communication means operates in the first communication mode when receiving the lens data, and the state When receiving data, the image pickup apparatus operates in the second communication mode.
The invention according to claim 9 is capable of outputting lens data, which is fixed data set for each photographing lens, and state data representing the state of the photographing lens, which can be detachably attached to the imaging apparatus. A communication unit that is a lens and operates by switching between a first communication mode and a second communication mode that is different from the first communication mode, and transmits and receives data to and from the imaging apparatus. And the communication means operates in the first communication mode when transmitting the lens data, and operates in the second communication mode when transmitting the state data. .

  According to the present invention, since data transfer is performed between the photographic lens and the imaging apparatus by a communication method according to transmitted data, a user-friendly camera system can be obtained.

1 is a perspective view showing a camera body 100 of a single-lens reflex camera to which the present invention is applied and a photographing lens 200 attached to the camera body 100. FIG. FIG. 2 is a block diagram illustrating configurations of a camera body 100 and a photographing lens 200. It is a figure which shows the example of the conversion table data with which the imaging lens 200 is provided. It is a figure which shows the outline | summary of the communication performed in two types of communication modes. It is a flowchart which shows the process at the time of switching the camera body 100 from a power-OFF state to an ON state. 6 is a flowchart showing processing when the photographic lens 200 is attached when the camera body 100 is in a power-off state. 6 is a flowchart showing processing when the photographic lens 200 is attached when the camera body 100 is in a power-on state. 4 is a flowchart showing a reception process of lens data 21 by the camera body 100 and a transmission process of lens data 21 by the photographing lens 200. It is a figure which shows the connection of the camera body 100 and the photographic lens 200 in a low speed mode. It is a figure which shows the connection of the camera body 100 and the photographic lens 200 in high speed mode. It is a figure which shows the example of a signal of the data transfer in a low speed mode. It is a figure which shows the example of a signal of the data transfer in high speed mode.

-First embodiment-
With reference to FIGS. 1-2, 1st Embodiment to which this invention is applied is described about a camera body and a photographic lens. FIG. 1 is a perspective view showing a camera body 100 of a single-lens reflex camera to which the present invention is applied and a photographing lens 200 attached to the camera body 100. FIG. FIG. The camera body 100 is provided with a control circuit 101 that controls each part of the camera body 100, an imaging unit 102, a release button 104, a camera side lens mount 108, and a recording medium mounting portion 100a. The recording medium 11 is inserted and attached to the recording medium mounting portion 100a.

  The camera body 100 has a quick return mirror 106. The camera side lens mount 108 is an attachment portion to which the photographing lens 200 is detachably attached to the camera body 100. The camera side lens mount 108 includes an electrical connection portion 109 including a plurality of terminals and a mechanical switch (not shown) that detects attachment / detachment of the photographing lens 200 to / from the camera body. The electrical connection unit 109 includes a plurality of terminals that perform data communication with the photographing lens 200 and a plurality of terminals that supply power to the photographing lens 200.

  The photographic lens 200 includes a lens side mount 201, a photographic optical system (not shown) that forms a subject image on the imaging unit 102 of the camera body, and a control circuit 205. The lens side mount 201 includes an electrical connection unit 202 having a plurality of terminals and a pressing unit (not shown) that presses the mechanical switch of the camera side lens mount 108. The electrical connection unit 202 includes a plurality of terminals that perform data communication with the camera body 100 and a plurality of terminals that receive power supply from the camera body 100.

  As shown in FIG. 2, the camera body 100 includes a distance measuring sensor 121, a photometric sensor 122, a monitor 123, a release switch 124, a communication unit 125, a light emitting device control unit 126, and a light emitting device 127. A power control circuit 128 and a built-in battery 129 are provided. The distance measuring sensor 121 is a sensor that outputs focusing information indicating a focusing state on a subject of the photographing optical system. The photometric sensor 122 is a sensor that outputs a photoelectric conversion signal for photometric processing corresponding to the brightness of the subject image.

  The monitor 123 is a monitor for displaying an image obtained by shooting, various information related to shooting, and the like, and is provided on the back surface of the camera body 100 using, for example, a liquid crystal display device. The release switch 124 outputs a release operation signal to the control circuit 101 in conjunction with the release button 104. The release operation signal includes a half-press operation signal corresponding to a half-press operation of the release button and a full-press operation signal corresponding to a full-press operation pressed deeper than the half-press operation. The communication unit 125 communicates with the photographing lens 200 attached to the camera body 100. The communication unit 125 further supplies power to the photographing lens 200. Power supply to the photographing lens 200 by the communication unit 125 is performed only when power is supplied to the communication unit 125. The light emitting device control unit 126 is a control unit that controls the illumination light irradiated to the subject by controlling the light emission of the light emitting device 127, and a photometric sensor (not shown) that detects the brightness of the subject light via the photographing lens 200. have.

  The power supply control circuit 128 uses the built-in battery 129 as a power supply, and supplies power to each member included in the camera body 100. The camera body 100 takes any one of the power-off state, the power-on state, and the communicable state. The power control circuit 128 determines to which member power is supplied according to the power state of the camera body 100. When the camera body 100 is in the power off state, no power is supplied to any member by the power control circuit 128. When the camera body 100 is in the power-on state, power is supplied to all members of the camera body 100 by the power supply control circuit 128. In a communicable state, the power supply control circuit 128 supplies power only to the communication unit 125, the main CPU 137, the memory 141, and the flash memory 142. When power is supplied to the communication unit 125, power is supplied to the photographing lens 200 by the communication unit 125. That is, when the camera body 100 is in a power-on state and when the camera body 100 is in a communicable state, power is supplied to the photographing lens 200.

  The imaging unit 102 is integrally provided with the imaging element 2 and an optical filter (not shown) disposed on the front surface of the imaging element 2. The image sensor 2 is constituted by an image sensor such as a CCD or CMOS which is an element for converting a subject image into an electrical image signal. The image sensor 2 captures an image of subject light that has passed through the photographing lens 200 and outputs an image signal (analog image signal). The recording medium 11 is a storage medium that can be attached to and detached from the camera body 100, such as a memory card, and stores image data that has been subjected to predetermined processing by the control circuit 101 as will be described later.

  As shown in FIG. 2, the photographing lens 200 is provided with a lens side blur correction device (lens side VR device) 210, a lens driving device 220, and a communication unit 240. The lens side VR device 210 is a device for correcting blurring of an optical image due to shake of the photographing lens 200 and the camera body 100 to which the photographing lens 200 is attached. The lens-side VR device 210 includes an acceleration sensor (lens-side acceleration sensor) 210 a for detecting a change in posture of the photographing lens 200 (amount of blur of the photographing lens 200), and a blur of a subject image on the imaging surface of the image sensor 2. A blur correction optical system (not shown) that corrects the image and a drive device (not shown) that drives the blur correction optical system are provided. The lens driving device 220 drives a focus lens (not shown) to advance and retreat in the optical axis direction in response to an instruction from the control circuit 205. The photographing lens 200 is provided with a focus ring (not shown) for manual focus adjustment, and the user can manually focus. The communication unit 240 communicates with the camera body 100 to which the photographing lens 200 is attached.

  When the photographing lens 200 is attached to the camera-side lens mount 108 of the camera body 100, the connection part 202 of the photographing lens 200 and the connection part 109 of the camera body 100 are connected. When the photographic lens 200 is attached to the camera side lens mount 108 of the camera body 100, a mechanical switch (not shown) provided on the camera side lens mount 108 is pressed by a pressing part (not shown) provided on the camera side lens mount 108. Then, the camera body 100 detects the mounting of the taking lens 200.

  As shown in FIG. 2, the control circuit 101 of the camera body 100 includes an AFE (Analog Front End) circuit 131, an A / D conversion circuit 132, a driver 133, a timing generator (TG) 134, and an image processing circuit 135. An image compression circuit 136, a main CPU 137, a buffer memory 138, and a display image creation circuit 139.

  The timing generator (TG) 134 generates a timing signal in response to an instruction sent from the main CPU 137 and supplies the timing signal to each of the driver 133, the AFE circuit 131, and the A / D conversion circuit 132. The driver 133 generates a drive signal necessary for the image sensor 2 to capture an image using the timing signal, and supplies the generated drive signal to the image sensor 2. The AFE circuit 131 performs analog processing (such as gain control) on the photoelectric conversion signal output from the image sensor 2. The A / D conversion circuit 132 converts the imaging signal after analog processing into a digital signal.

  The main CPU 137 receives a signal output from each block, performs a predetermined calculation, and outputs a control signal based on the calculation result to each block. The image processing circuit 135 is configured as an ASIC, for example, and performs image processing on the digital image signal input from the A / D conversion circuit 132. For image processing, for example, grouping processing for detecting subject brightness, contrast, and the like corresponding to each predetermined area on the image sensor 2, contour enhancement and color temperature adjustment (white balance adjustment) for the image signal from the image sensor 2 ) Processing, image correction processing to be described later based on lens data information, format conversion processing for the image signal, and the like.

  The image compression circuit 136 performs image compression processing on the image signal processed by the image processing circuit 135 at a predetermined compression ratio using the JPEG method. The display image creation circuit 139 creates display data for displaying the captured image on the monitor 123.

  In the recording medium 11 mounted on the recording medium mounting unit 100a, the image file including the data of the captured image and the information thereof is recorded according to an instruction from the main CPU 137. The image file recorded on the recording medium 11 can be read by an instruction from the main CPU 137. The buffer memory 138 temporarily stores data before and after image processing and in the middle of image processing, stores an image file before recording on the recording medium 11, and stores an image file read from the recording medium 11. Used for.

  The control circuit 101 of the camera body 100 includes a memory 141 and a flash memory 142. The memory 141 is a memory including a ROM for storing a control program, various setting values set in advance, and a RAM for a work area. Body data unique to the camera body 100 is recorded in the ROM. The body data includes information about the camera body 100 used by the photographing lens 200, such as the weight of the camera body 100 used by the lens-side VR device 210, for example. The main CPU 137 accesses the memory 141, executes a control program, and performs various controls. The flash memory 142 stores lens data (described later) sent from the taking lens 200.

  The control circuit 205 of the photographing lens 200 includes a main CPU 231 and a memory 232. The main CPU 231 inputs a signal output from each block, performs a predetermined calculation, and outputs a control signal based on the calculation result to each block. The memory 232 is a memory including a ROM for storing control programs, lens data, and the like, and a RAM for a work area.

  Next, lens data will be described. The lens data is data representing the characteristics of the photographing lens 200, and is fixed data set for each individual photographing lens. The lens data includes conversion table data (to be described in detail later) regarding focal length, zoom position, and open F value, data representing optical characteristics of the photographing lens 200, and lens identifiers that differ for each individual photographing lens. It is.

Examples of data representing the optical characteristics of the fixed data of the photographing lens 200 include, for example, magnification chromatic aberration parameters, axial chromatic aberration parameters, coma aberration parameters, distortion aberration parameters, peripheral dimming parameters, γ value parameters, and white balance parameters. , Contour correction parameters, parameters related to vignetting, parameters related to the amount of defocus due to the aperture value, and the like.
Of the above, for example, the aberration data varies depending on the position of the movable lens (zoom lens or focusing lens) included in the photographing lens 200 in the optical axis direction. Such aberration data is in the form of conversion table data similar to that described later with reference to FIG. 3C for each image height position of the photographic lens, or in the form of a coefficient of an approximate expression representing the aberration for each image height position. Data corresponding to the position of the movable lens is stored in the memory 232 in the photographing lens 200.

The lens data may include data different from the above three types. For example, it relates to the focus adjustment of the photographing lens 200, such as data relating to the image plane movement amount per pulse of the lens drive command from the camera body side, data relating to the play (mechanical play) of the lens drive system (drive amount difference information), and the like. Information may be included. All the lens data described above is stored in the ROM 232 and is not changed.
As described above, the lens data includes various types of data as described above and a large amount of data.

  The camera body 100 stores the lens data described above in the flash memory 142, and controls the photographing lens 200 and performs various image processing. When the photographing lens 200 is attached when the camera body 100 is in the power-on state, a mechanical switch (not shown) provided in the camera body 100 is pressed according to the attachment (attachment), and the mechanical switch is connected to the main CPU 137. A signal indicating that the button has been pressed is input. Thereby, the camera body 100 can detect the mounting of the photographing lens 200. The camera body 100 that has detected the mounting of the photographic lens 200 checks whether the lens data of the mounted photographic lens 200 is stored in the flash memory 142 using the lens identifier 21C. If it is determined that the lens data is not stored in the flash memory 142 or that the lens data stored in the flash memory 142 is different from the lens data of the currently mounted photographic lens 200, the photographic lens 200 The lens data is received and stored in the flash memory 142.

  On the other hand, when the photographing lens 200 is attached when the camera body 100 is in the power-off state, a signal indicating that the mechanical switch is pressed is input to the power control circuit 128 by pressing a mechanical switch (not shown). The In response to this signal, the power control circuit 128 changes the power state of the camera body 100 from the power-off state to the communicable state. The camera body 100 in the communicable state checks whether the lens data of the attached photographing lens 200 is stored in the flash memory 142 as in the case of the power-on state described above. If it is determined that the lens data is not stored in the flash memory 142 or that the lens data stored in the flash memory 142 is different from the lens data of the currently mounted photographic lens 200, the photographic lens Lens data is received from 200 and stored in the flash memory 142. The camera body 100 transitions to the power-off state again after executing the above processing.

  Next, conversion table data included in the lens data will be described. The photographing lens 200 is a so-called zoom lens, and its focal length is changed by a zoom operation. Further, the focus position of the photographing lens 200 (here, the position of the subject whose focus is adjusted, that is, the distance is referred to as the focus position) is changed by the focus adjustment operation. The photographic lens 200 also changes its open F value according to a change in focal length or a change in focus position. The data regarding the focal length, the focus position, and the open F value (the numerical data of the focal length itself, the numerical data of the focus position itself, and the numerical data of the open F value itself) are referred to as optical system data of the photographing lens 200. .

  Since the camera body 100 performs image processing and control of the photographing lens 200 using the above-described optical system data, it is necessary to acquire the optical system data of the photographing lens 200 in real time during the photographing operation. The photographic lens 200 in this embodiment is not limited to transmitting optical system data (numerical data of the focal length itself, numerical data of the focus position itself, and numerical data of the open F value itself) to the camera body 100 in advance. Data referred to as status data (details will be described later) converted to optical system data using conversion table data (stored in the memory 232 in the photographing lens 200) transmitted from the camera 200 to the camera body 100. Send. That is, the photographic lens 200 transmits the state data to the camera body 100 after converting the optical system data into the state data using the conversion table data in the memory 232. Here, the state data is data whose data amount is smaller than optical system data (that is, numerical data of each state amount itself). The camera body 100 can acquire the optical system data of the photographing lens 200 by converting the received state data using the conversion table data of the photographing lens 200. Below, the content of the conversion table data and the acquisition method of optical system data are demonstrated.

  FIG. 3 is a diagram illustrating an example of conversion table data included in the photographing lens 200. FIG. 3A shows a focal length table 12A, FIG. 3B shows a focus position table 12B, and FIG. 3C shows an open F value table 12C.

The focus position table 12A stores a set value list of focus positions of the photographing optical system, and an index value starting from 1 is assigned to each set value. Ten setting values are stored in the focus position table 12A in the present embodiment.
The focal length table 12B stores a list of set values of the focal length of the photographing optical system, and an index value starting from 1 is assigned to each set value. Ten set values are stored in the focal length table 12B in this embodiment.
The set values stored in the focus position table 12A and the focal length table 12B may be more or less than ten. The number of setting values stored in each of these two tables may be different from each other.

The open F value table 12C is a table in which open F values corresponding to the focus position and focal length of the photographing optical system are stored. For example, when the focus position is set to infinity (index value 1) and the focal length is set to 200 mm (index value 10), the open F value is 5.6 from FIG. In the present embodiment, there are 10 types of setting values for the focal length and 10 types of setting values for the focus position. Therefore, 10 × 10 = 100 setting values are stored in the open F value table 12C.
By providing these three tables 12A to 12C, if only two types of information such as focal length and focus position can be obtained, the third information (third type of open F value) can be obtained using the table 12c of FIG. Information) is also available.

Hereinafter, a method for acquiring optical system data of the photographing lens 200 using these three tables will be described. It is assumed that the conversion table data acquired from the photographing lens 200 has already been stored in the camera body 100. The photographic lens 200 refers to the focus position table 12A and acquires an index value corresponding to the current focus position of the photographic optical system (in other words, the position of the focusing lens). Similarly, the photographic lens 200 refers to the focal length table 12B and acquires an index value corresponding to the current focal length of the imaging optical system (in other words, the position of the zoom lens). Thereafter, the photographing lens 200 transmits these two index values to the camera body 100. The camera body 100 receives the above two index values and refers to the focus position table 12A and the focal length table 12B to refer to the focus position and focal length of the photographing optical system, and to the open F value table 12C. The open F value of the photographing optical system is acquired.
Here, the above two index values are referred to as state data of the photographing lens 200. The data amount of the index value is smaller than the numerical data of each state quantity itself (for example, the data amount of the focal length “200 mm”). Further, as described above, by transmitting two index values (state data) respectively indicating the focus position and the focal length, three types of optical system data (the focus position, the focal length, and the open F value) are consequently obtained. Therefore, more information can be transmitted to the camera body 100 with a small amount of transmission data.

Next, an outline of communication performed between the camera body 100 and the photographing lens 200 will be described. Data transferred between the camera body 100 and the taking lens 200 includes lens data, state data, body data, control data, and focus adjustment data.
Here, the control data is data including a control command for controlling the photographing lens 200, or data such as a lens identifier request for instructing the photographing lens 200 to transmit a lens identifier.
The focus adjustment data is data representing the amount and direction of movement of the focus lens included in the photographing optical system of the photographing lens 200. More specifically, there are two pulse train signals representing the amount and direction of movement of the focusing lens, the amount of movement being represented by the number of pulses of the two pulse train signals, and the direction of movement being represented by the phase difference between the two. .

In this embodiment, there are two types of communication modes called a one-way communication mode (hereinafter also referred to as a high-speed mode) and a bidirectional communication mode (hereinafter also referred to as a low-speed mode). These two communication modes have different communication methods as will be described later.
The high speed mode is a communication mode used when transferring lens data, body data, and control data. Communication in the high-speed mode can be performed in full duplex (that is, bidirectional parallel communication using separate one-way communication lines), and burst transfer is performed in order to cope with large data transfer. Thereby, the communication in the high speed mode can be performed at a higher speed than in the low speed mode.
On the other hand, the low-speed mode is a communication mode used for transferring state data, focus adjustment data, and control data. In this low-speed mode, a communication line (communication contact) used for bidirectional communication (request communication from one to the other and response communication from the other to the one according to the request) is also used. Mode. In order to perform bidirectional communication using the dual-purpose communication line, it is necessary to switch the communication direction. Furthermore, communication from one to the other cannot be started in the middle of communication from one to the other (in other words, in order to start communication from one to the other, the end of communication from one to the other must be waited) thing). For this reason, in the low speed mode, for example, when performing bidirectional communication of requesting a predetermined amount of data from one to the other and transferring a predetermined amount of data from the other to the corresponding one, the high speed mode It takes longer time to transfer data (in other words, the communication is slower than the high speed mode).
In the present embodiment, the lens data is communicated in the high-speed mode at the timing when the focus adjustment data need not be communicated, such as immediately after the taking lens is replaced or immediately after the camera body is turned on. Yes. On the other hand, during the shooting operation (period in which the focus adjustment data needs to be communicated), the status data is communicated in the low speed mode.
Hereinafter, communication contents and communication procedures in each communication mode will be described with reference to FIG.

  FIG. 4 is a diagram illustrating an outline of communication performed in two types of communication modes. First, communication in the low speed mode will be described with reference to FIG. 4A, and then communication in the high speed mode will be described with reference to FIG. 4B.

  As shown in FIG. 4A, there are two communication paths 33 and 34 between the camera body 100 and the photographing lens 200. In the low-speed mode, the communication path 33 is used to transfer the above-described state data and control data (control command), and the communication path 34 is used to control the focus adjustment operation associated with the photographing operation. Used to transfer two pulse train signals representing the amount of movement and the direction of movement). That is, in this communication in the low speed mode, data representing the focus adjustment state (focusing state) and the focal length adjustment state (zooming state) of the photographing optical system is sent from the photographing lens 200 to the camera body 100, and the camera body 100 takes a photograph. Various control commands related to photographing (for example, control commands for driving the focusing lens for focus adjustment) and data representing various data requests are sent to the lens 200.

  Hereinafter, a procedure in which the camera body 100 performs communication in the low speed mode and acquires data representing the focus adjustment state and the focal length adjustment state of the photographing optical system will be described with reference to FIG. First, the state data request 25 is transmitted from the camera body 100 to the photographing lens 200 via the communication path 33. In response to the request 25, the photographic lens 200 transmits the state data 26 to the camera body 100 via the communication path 33. As described above, the state data 26 is two index values. As described above, both the status data request 25 and the status data 26 are transmitted through the communication path 33. That is, the communication path 33 at this time is a transmission path for the request 25 from the camera body 100 and a bidirectional communication path that is also used as a transmission path for the status data 26 from the photographing lens 200. For this reason, in the bidirectional communication via the communication path 33, the signal transmission / reception direction (communication) is determined depending on whether the communication from the camera body 100 to the photographing lens 200 is performed or the communication from the photographing lens 200 to the camera body 100 is performed. (Direction) must be switched. This switching operation will be described later.

  The camera body 100 that has received the state data 26 converts the received state data 26 using the conversion table data 27 of the photographing lens 200 acquired in advance. By this conversion, optical system data of the photographing lens 200, that is, focal length data 28, focus position data 29, and open F value data 30 are obtained. The camera body 100 uses these three data to perform image processing and control of the photographing lens 200.

  The photographic lens 200 transmits the above-described focus adjustment data 31 (two pulse train signals indicating the moving amount and moving direction of the focusing lens) to the camera body 100 in parallel with the communication using the communication path 33 described above. The communication path 34 is used for the transfer of the focus adjustment data 31 and is performed asynchronously with the communication using the communication path 33. Specifically, the focus adjustment data 31 is transmitted from the photographing lens 200 to the camera body 100 each time the focus lens of the photographing optical system moves.

  Next, communication in the high speed mode will be described with reference to FIG. In the high speed mode, lens data, body data, and control data are transferred. FIG. 4B shows a state before these data are transferred. That is, the photographing lens 200 includes lens data 21, and the camera body 100 includes body data 24. The lens data 21 includes conversion table data 21A, data 21B representing optical characteristics, and a lens identifier 21C. The flash memory 142 of the camera body 100 stores lens data (stored lens data 22) of a photographing lens that is attached in front of the photographing lens 200 and is different from the photographing lens 200. Similar to the lens data 21, the stored lens data 22 includes conversion table data, data representing optical characteristics, and a lens identifier (stored lens identifier 22C).

  The camera body 100 requires the lens data 21 of the photographic lens 200 for control and image processing of the photographic lens 200 currently mounted (mounted) on the camera body 100. In communication in the high speed mode, the lens data 21 is transmitted from the photographing lens 200 to the camera body 100. The camera body 100 stores the received lens data in the flash memory 142 and uses it for control of the photographing lens 200 and image processing.

  However, when the stored lens data 22 stored in the flash memory 142 is the same data as the lens data 21 of the photographing lens 200, it is not necessary to transfer the lens data 21. Therefore, in the communication in the high speed mode, only the lens identifier 21C is first transmitted to the camera body 100 before the entire lens data 21 is transferred. The camera body 100 compares the received lens identifier 21 </ b> C and the stored lens identifier 22 </ b> C to determine whether the stored lens data 22 is the same data as the lens data 21. If the two lens identifiers match, the camera body 100 determines that the two lens data are the same data, and does not transfer the entire lens data 21.

  In the communication in the high speed mode, first, the camera body 100 transmits the lens identifier request 23 using the communication path 33. The taking lens 200 transmits a lens identifier 21C in response to the request 23. The lens identifier 21 </ b> C is data unique to each photographing lens included in the lens data 21, and is transmitted through the communication path 34. Upon receiving the lens identifier 21C, the camera body 100 compares the stored lens identifier 22C stored in the flash memory 142 with the received lens identifier 21C. If they match, it is determined that the lens data 21 and the stored lens data 22 are the same, and the lens data 21 is not transferred.

  On the other hand, if the lens identifier 21C and the stored lens identifier 22C do not match, the camera body 100 transmits a lens data request (not shown) through the communication path 33. The taking lens 200 transmits the lens data 21 through the communication path 34 in response to the request. The camera body 100 that has received the lens data 21 overwrites the stored lens data 22 with the received lens data 21. Thereby, the flash memory 142 is in a state where the lens data 21 of the photographing lens 200 is stored.

In communication in the high-speed mode, the photographing lens 200 may transmit a body data request (not shown) through the communication path 34 after comparing the lens identifier 21C and the stored lens data 22C described above. When the camera body 100 receives the body data request, the camera body 100 transmits the body data 24 through the communication path 33. The transmission of the body data 24 by the camera body 100 and the transmission of the lens data 21 by the photographing lens 200 are performed using different communication paths. Therefore, these two communications are performed in parallel.
As described above, in the high-speed mode, communication is performed via the communication path 33 when communication from the camera body 100 to the photographing lens 200 is performed, and communication is performed when communication from the photographing lens 200 to the camera body 100 is performed. This is performed via the road 34. That is, in the high-speed mode, the communication paths 33 and 34 function as dedicated communication paths with one communication direction without switching the communication direction.

Next, the power supply state change and communication processing by the camera body 100 will be described with reference to the drawings.
FIG. 5 is a flowchart showing processing when the camera body 100 is shifted from the power-off state to the power-on state (power switch on operation). Assume that the camera body 100 is in a power-off state and the photographing lens 200 is already attached to the camera body 100 at the start of the processing shown in the flowchart.
First, in step S1, it is determined whether or not an operation of turning on a power switch (not shown) of the camera body 100 has been performed.
In step S2, the camera body changes from the power-off state to the on-state in response to the power-on operation, and the main CPU 137 sets the communication mode of the communication unit 125 to the high-speed mode. At this time, the communication mode of the communication unit 240 of the photographing lens 200 is also set to the high speed mode by the main CPU 231 on the photographing lens side that has received the communication mode switching command from the main CPU 137.
In step S2, the main CPU 137 on the camera body side is described as instructing the main CPU 231 on the photographing lens side to switch the communication mode. However, the communication mode of the communication unit 240 on the photographing lens side is normally set to (Camera If the high-speed mode is set (when there is no command to switch to the low-speed mode from the body side), the high-speed mode switching process of the communication unit 240 is not necessary here.
In step S <b> 3, the lens identifier 21 </ b> C of the photographing lens 200 is received, and it is determined whether or not the received lens identifier 21 </ b> C matches the stored lens identifier 22 </ b> C of the flash memory 142. If they match, the process proceeds to step S5, and the lens data 21 is not received.
On the other hand, if a negative determination is made in step S3, the process proceeds to step S4, lens data 21 is received and stored in the flash memory 142, and the process proceeds to step S5.
In step S5, the communication modes of the communication units 125 and 240 of both the camera body 100 and the photographing lens 200 are set to the low speed mode. Since the communication mode switching method here is also as described in step S2, description thereof is omitted here.
In step S6, state data is periodically received from the photographing lens 200, and a photographing operation or the like is performed. Thereafter, a power-off operation is performed in step S7, and the camera body 100 transitions to the power-off state again.
The above is the flow of processing when the camera body is turned on.
FIG. 6 is a flowchart showing processing when the photographic lens 200 is attached when the camera body 100 is in the power-off state. At the start of the processing shown in the flowchart, the camera body 100 is in a power-off state, and the taking lens 200 is not yet attached.

  First, in step S11, the taking lens 200 is attached. Corresponding to the mounting of the taking lens 200, the camera body transitions from the power-off state to the communicable state in step S12. The communication mode is a high speed mode. The method for switching the communication mode is the same as the method already described in FIG. In step S13, the lens identifier 21C of the photographing lens 200 is received, and it is determined whether or not the received lens identifier 21C matches the stored lens identifier 22C of the flash memory 142. If they match, the process proceeds to step S15, and the lens data 21 is not received. On the other hand, if a negative determination is made in step S13, the process proceeds to step S14, lens data 21 is received and stored in the flash memory 142, and the process proceeds to step S15.

  In step S15, the state again changes to the power-off state and waits for a power-on operation. In step S16, in response to a power-on (power-on) operation, the power-on state is entered. In step S17, the lens identifier 21C is compared with the stored lens identifier 22C in the same manner as in step S13, and a match between the two is confirmed. In step S18, the communication mode is set to the low speed mode. In step S19, state data is periodically received from the photographing lens 200, and a photographing operation or the like is performed. Thereafter, a power off operation is performed in step S20, and the camera body 100 transitions to the power off state again.

The above is the processing flow when the taking lens 200 is attached in the power-off state. Note that the processing in steps S12 to S15 may not be executed when the photographic lens 200 is attached (replaced) because the built-in battery 129 is removed from the camera body 100 or the like. In this case, in the operation flow described above, the two lens identifiers do not match in step S17. Therefore, a mechanical switch (not shown) for detecting the mounting of the built-in battery 129 is provided in the vicinity of the battery compartment of the camera body 100, and when the mechanical switch detects the mounting of the built-in battery 129, the processing of steps S12 to S15 is executed. Make sure you do. By doing so, it is possible to confirm that the lens identifiers match each time the built-in battery is mounted. If they do not match, the lens data 21 reception process and the flash memory 142 storage process are executed. Therefore, when the photographing operation is performed in step S19, the lens data 21 of the photographing lens 200 is stored in the flash memory 142, and the photographing lens 200 can be controlled and image processing can be performed correctly.
Note that a battery loading detection signal by a mechanical switch that detects the mounting of the internal battery 129 may be notified to the photographing lens 200 side via the communication unit 125 and the communication unit 240. With this configuration, the photographic lens 200 receives the battery loading detection signal, and the main CPU 231 selects (extracts) only the lens identifier 21C from the lens data to the camera body 100 side. First, it can be separated from other lens data (such as conversion table data) and automatically transmitted to the camera body 100. In addition, when the camera lens 100 communicates a signal indicating a mismatch of the lens identifier 21C or a signal requesting the remaining lens data other than the lens identifier 21C, the photographing lens 200 responds to the main CPU 231. Transmits the remaining lens data to the camera body 100.
Note that the condition for causing the photographing lens 200 to perform the communication operation in this manner is not limited to when the battery loading detection signal is received. When the above-described power-on operation on the camera body side (ON of a mechanical switch (not shown) that is pressed in accordance with the above-described power-on operation) is detected, and a signal indicating this is transmitted to the photographing lens 200, The main CPU 231 operates in the same manner as described above.

  Next, processing when the photographing lens 200 is attached when the camera body 100 is in the power-on state will be described with reference to FIG. FIG. 7 is a flowchart showing processing when the photographic lens 200 is attached when the camera body 100 is in the power-on state. Similar to FIG. 6, at the start of the processing shown in the flowchart, the camera body 100 is in a power-off state, and the taking lens 200 is not yet attached.

  First, in step S21, a transition to the power-on state is made in response to the power-on operation. Unlike step S16 (FIG. 6), since the taking lens 200 is not yet attached, the process of comparing lens identifiers as in step S17 is not executed. In step S22, the taking lens 200 is attached. In step S23, the communication mode is changed to the high speed mode in accordance with the mounting of the taking lens 200. In step S24, the lens identifier 21C of the taking lens 200 is received as in step S13, and it is determined whether or not the received lens identifier 21C matches the stored lens identifier 22C of the flash memory 142. If they match, the process proceeds to step S26, and the lens data 21 is not received. On the other hand, if a negative determination is made in step S24, the process proceeds to step S25, the lens data 21 is received and stored in the flash memory 142, and the process proceeds to step S26.

  In step S26, the communication mode is set to the low speed mode. In step S27, state data is periodically received from the photographing lens 200, and a photographing operation or the like is performed. Thereafter, a power off operation is performed in step S28, and the camera body 100 transitions to the power off state again. The above is the processing flow when the taking lens 200 is attached in the power-on state.

  Next, transfer processing of the lens identifier 21C and the lens data 21 will be described in more detail with reference to FIG. FIG. 8 is a flowchart showing the reception processing of the lens data 21 by the camera body 100 and the transmission processing of the lens data 21 by the photographing lens 200.

  First, processing of the camera body 100 will be described. First, in step S <b> 31, the lens identifier request 23 is transmitted from the camera body 100 to the photographing lens 200. In step S32, the taking lens 200 receives the lens identifier 21C transmitted in step S42. In step S33, it is determined whether or not the received lens identifier 21C matches the stored lens identifier 22C. If they match, the lens data 21 is not received and the process is terminated. On the other hand, if a negative determination is made in step S33, the process proceeds to step S34.

  In step S34, a lens data request is transmitted to the taking lens 200. In step S35, the lens data 21 transmitted from the photographing lens 200 in step S44 is received. In step S36, the lens data 21 received in step S35 is stored in the flash memory 142, and the process ends.

  Next, processing of the taking lens 200 will be described. First, in step S41, the camera body 100 receives the lens identifier request transmitted in step S31, and proceeds to step S42. In step S42, the lens identifier 21C is transmitted to the camera body 100. In step S43, it is determined whether the camera body 100 has received the lens data request transmitted in S34. If the camera body 100 has transmitted a lens data request, the process proceeds to step S44, where the lens data 21 is transmitted to the camera body 100, and the process ends. On the other hand, if the camera body 100 has not transmitted the lens data request, a negative determination is made in step S43, and the process is terminated without transmitting the lens data 21.

  In step S54, a lens data request is transmitted to the taking lens 200. In step S55, the lens data transmitted by the photographic lens 200 through the process of step S64 (described later) is received. In step S56, the lens data received in step S55 is stored in the flash memory 142. The lens data 21 acquisition process by the camera body 100 has been described above.

  In step S17 in FIG. 6 and steps S24 to S25 in FIG. 7, body data is transferred from the camera body 100 to the photographing lens 200. The body data is transferred regardless of the comparison result of the lens identifier. Further, while the lens data is being transferred, the body data is transferred in parallel with the lens data.

  Next, specific operations in the two types of communication modes will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram illustrating the connection between the camera body 100 and the photographing lens 200 in the low speed mode, and FIG. 10 is a diagram illustrating the connection between the camera body 100 and the photographing lens 200 in the high speed mode. 9 and 10 show a state in which the photographing lens 200 is attached to the camera body 100 and the photographing lens side connection portion 202 shown in FIG. 2 is electrically connected to the camera body side connection portion 109. .

  9 and 10, the camera body side connecting portion 109 has six contacts 109a to 109f, and similarly, the taking lens side connecting portion 202 has six contacts 202a to 202f. In the figure, the fact that these contacts 109a to 109f are connected to the contacts 202a to 202f is represented by six transmission lines 40, 41, 33a, 33b, 34a, and 34b. The communication unit 125 of the camera body 100 includes a power output terminal 125a, a clock input terminal 125b, a first handshake output terminal 125c, a first data output terminal 125d, a first data input terminal 125e, a first pulse input terminal 125f, and a second interrupt. The input terminal 125g and the second pulse input terminal 125h have a total of eight terminals, and the number thereof is larger than the number of contacts provided in the camera body side connecting portion 109. Similarly, the communication unit 240 of the photographing lens 200 also includes a power input terminal 240a, a clock output terminal 240b, a first interrupt input terminal 240c, a second data input terminal 240d, a first data output terminal 240e, a first pulse output terminal 240f, The two handshake output terminals 240g and the second pulse output terminal 240h have a total of eight terminals, and the number thereof is larger than the number of contacts provided in the photographing lens side connection unit 202.

  A power output terminal 125a, a clock input terminal 125b, a first handshake output terminal 125c, a first data output terminal 125d, and a first pulse input terminal included in the communication unit 125 of the camera body 100 are contacts 109a, 109b, 109c, 109d, 109e. The first data input terminal 125e is alternatively connected to the contact 109d and the contact 109e by the switch 43. The second interrupt input terminal 125g and the second pulse input terminal 125h are both connected to the contact 109f.

  A power input terminal 240a, a clock output terminal 240b, a first interrupt input terminal 240c, a second data input terminal 240d, and a first pulse output terminal 240f included in the communication unit 240 of the photographing lens 200 are contacts 202a, 202b, 202c, and 202d, respectively. , 202e. The second data output terminal 240e is alternatively connected to the contact 202d and the contact 202e by the switch 42. The second handshake output terminal 240g and the second pulse output terminal 240h are both connected to the contact 202f.

  Next, it will be described in detail how signals are transmitted and received between the eight terminals of the communication units 125 and 240 via the six contacts of the connection units 109 and 202, respectively. In FIGS. 9 and 10, broken-line arrows connecting the respective terminals indicate the input / output directions of signals transmitted and received between the terminals.

  First, the operation of each terminal in the low speed mode will be described with reference to FIG. The power output terminal 240 a is a terminal that outputs power for operating the photographing lens 200 supplied from the power control circuit 128 to the photographing lens 200. The output from the power output terminal 125a is input to the power input terminal 240a on the photographing lens side through the transmission line 40. The clock output terminal 240b is a terminal from which a clock signal used for data transfer is output. The clock signal output from the clock output terminal 240b is input through the transmission line 41 to the clock input terminal 125b on the camera body side.

  The first handshake output terminal 125c outputs a handshake signal indicating whether communication is being executed. The handshake signal output from the first handshake output terminal 125c is input to the first interrupt input terminal 240c through the transmission line 33a. The first interrupt input terminal 240c detects a change in the handshake signal at the start of communication and generates an interrupt to the communication unit 240. Upon receiving an interrupt from the first interrupt input terminal 240c, the communication unit 240 detects that an instruction to start communication is received from the camera body 100, and starts preparation for communication.

  The first data output terminal 125d, the first data input terminal 125e, the second data input terminal 240d, and the second data output terminal 240e are terminals for inputting and outputting data signals. In the low-speed mode shown in FIG. 9, the first data input terminal 125e is connected to the contact 109d by the switch 43, and the second data output terminal is connected to the contact 202d by the switch 42. Therefore, since the input / output of data signals by these four terminals is performed only through the transmission line 33b, data transfer from the camera body 100 to the photographing lens 200 and data transfer from the photographing lens 200 to the camera body 100 are performed. It cannot be done at the same time. In each direction of communication from the camera body 100 to the photographing lens 200 or from the photographing lens 200 to the camera body 100, it is necessary to switch the validity / invalidity of the terminals 125d, 125e, 240d, and 240e in time series as described later. is there. A clock signal passing through the transmission line 41 is used for data transfer by these terminals.

  The first pulse output terminal 240f and the second pulse output terminal 240h are terminals for outputting a two-phase pulse signal. This two-phase pulse signal represents the amount and direction of movement of a focus lens (not shown) included in the photographing lens 200. Two-phase pulse signals output from these terminals are input to the first pulse input terminal and the second pulse input terminal on the camera body side through transmission lines 34a and 34b. Receiving the two-phase pulse signal, the communication unit 125 detects the amount and direction of movement of the focus lens from the pulse signal, and outputs them to the main CPU 137 in FIG.

  In the low-speed mode, the second interrupt input terminal 125g included in the communication unit 125 of the camera body 100 and the second handshake output terminal 240g included in the communication unit 240 of the photographing lens 200 are the communication unit 125 and the communication unit 240, respectively. Is disabled by Therefore, no signal is output from these terminals, and the communication unit 125 and the communication unit 240 do not perform any operation in accordance with the signals input to these terminals.

  Next, the operation of each terminal in the high-speed mode will be described with reference to FIG. In the high-speed mode, the second interrupt input terminal 125g included in the communication unit 125 of the camera body 100 and the second handshake output terminal 240g included in the communication unit 240 of the photographing lens 200, which are invalid in the low-speed mode, are enabled. Is set. Instead, the first pulse input terminal 125f and the second pulse input terminal 125h included in the communication unit 125 of the camera body 100, and the first pulse output terminal 240f and the second pulse output terminal 240h included in the communication unit 240 of the photographing lens 200. Is set to invalid. In the high-speed mode, the first data input terminal 125e is connected to the contact 109e by the switch 42, and the second data output terminal 240e is connected to the contact 202e by the switch 43.

  As a result of switching the connection by the switches 42 and 43, only the first data output terminal 125d and the first data input terminal 202d are connected to the transmission line 33b, and the second data output terminal 240e and the second data line are connected to the transmission line 34a. Only the data input terminal 125e is connected. As a result, the transmission line 33b becomes a one-way dedicated communication path from the camera body 100 to the photographing lens 200, and the transmission line 34a becomes a one-way dedicated communication path from the photographing lens 200 to the camera body 100. The control command and data transfer from the photographic lens 200 to the photographic lens 200 and the data transfer from the photographic lens 200 to the camera body 100 can be performed simultaneously in parallel. That is, full-duplex communication between the camera body 100 and the taking lens 200 is possible.

  As full-duplex communication becomes possible, a signal output from the first handshake output terminal 125c is transmitted between the first data output terminal 125d and the first data input terminal 240d. It is handled as a handshake signal indicating whether or not communication is being executed. Further, from the second handshake output terminal 240g, a handshake signal indicating whether or not communication using the transmission line 34a, that is, communication performed between the second data output terminal 240e and the second data input terminal 125e is being executed. Is output. This handshake signal is input to the second interrupt input terminal 125g through the transmission line 34b. Similar to the first interrupt input terminal 240c, the second interrupt input terminal 125g detects a change in the handshake signal at the start of communication and causes the communication unit 125 to generate an interrupt.

  As described above, the transfer of the status data and control data in the low-speed mode is performed while switching the transfer (transmission) direction using only one transmission line 33b. On the other hand, in communication in the high-speed mode, two types of data transfer with different transfer (transmission) directions can be simultaneously performed using the transmission lines 33b and 34a.

  Next, output signals in each communication mode will be described with reference to the drawings. First, the output signal in the low speed mode will be described with reference to FIG. 11, and then the output signal in the high speed mode will be described with reference to FIG.

  FIG. 11 is a diagram illustrating an example of a signal for data transfer in the low speed mode. 11A shows data transfer from the camera body 100 to the taking lens 200, and FIG. 11B shows data transfer from the taking lens 200 to the camera body 100.

  Data transfer from the camera body 100 to the photographing lens 200 will be described with reference to FIG. When communication is not being performed in the low speed mode, a signal of H (High) level is output from the first handshake output terminal 125c, the clock output terminal 240b, the first data output terminal 125d, and the second data output terminal 240e. ing. When communication is started (T61), the camera body 100 sets the output of the first handshake output terminal 125c to L (Low) level. Thereby, the photographing lens 200 starts preparation for data transfer (data reception).

When preparation for reception is completed on the photographing lens 200 side (T62), the clock signal is output from the clock output terminal 240b for 8 clocks. The camera body 100 outputs a data signal 51 representing 1 byte (8 bits) of control data from the first data output terminal 125d in accordance with the clock signal. A data signal 51 shown in FIG. 11A is control data meaning that 2-byte data is transmitted from the camera body 100 to the taking lens 200 following the control data.
That is, the above-described clock signal output from the photographing lens 200 functions as a synchronous clock signal for the camera body 100 to output data, and prepares to receive data output from the camera body 100 on the lens side. Has a function as a signal for notifying the camera body 100 that the data has been completed (allowing data output operation on the camera body 100 side).

  In the low-speed mode, every time a data signal for 1 byte is output, the handshake signal output from the first handshake output terminal 125c becomes H level (T63). The camera body 100 sets the output signal of the first handshake output terminal 125c to the L level in order to output the 2-byte data transmitted to the photographing lens 200 following the data signal 51. Thereafter, a clock signal is output as in the case of the data signal 51, and the data signal 52 and the data signal 53 corresponding to the data signal 51 are transferred. Data transfer from the camera body 100 to the photographing lens 200 is performed according to the above procedure.

  Next, data transfer from the photographing lens 200 to the camera body 100 will be described with reference to FIG. A handshake signal indicating whether communication is being performed is output from the first handshake output terminal 125c, but the photographing lens 200 cannot control the first handshake output terminal 125c. Accordingly, in the low speed mode, the photographing lens 200 cannot actively start communication with the camera body 100. Data transfer from the taking lens 200 to the camera body 100 is always performed in response to a data request from the camera body 100.

  In the data transfer from the photographing lens 200 to the camera body 100, first, similarly to the case of FIG. 11A, a data signal 54 representing predetermined control data is exchanged (T65). The control data represented by the data signal 54 is control data which means that 1-byte data is transmitted from the photographing lens 200 to the camera body 100 following the control data. When the transfer of the control data is completed and the output signal from the first handshake output terminal 125c becomes H level (T67), the transfer direction of the input terminal and the output terminal is switched in both the camera body 100 and the photographing lens 200. Is called. Specifically, the camera body 100 invalidates the first data output terminal 125d used so far and validates the first data input terminal 125e. Similarly, the photographing lens 200 invalidates the second data input terminal 240d used so far and validates the second data output terminal 240e.

  The camera body 100 sets the output signal of the first handshake output terminal 125c to L level when the switching of the first data output terminal 125d and the first data input terminal 125e is completed (T66). The photographic lens 200 has a clock signal from the clock output terminal 240b when the output signal of the first handshake output terminal 125c is L level and the switching of the second data output terminal 240d and the second data input terminal 240e is completed. Starts output. Since the transfer direction is switched as described above, in the data transfer from the photographing lens 200 to the camera body 100, the time from the completion of transmission of control data (T65) to the start of transmission of data following the control data (T67) This is longer than when data is transferred from the body 100 to the taking lens 200 (T63 to T64). When all data transfer is completed, the transfer direction is switched again to restore the transfer direction to the original. Data transfer in the low-speed mode is executed as described above.

  Next, output signals in the high speed mode will be described. FIG. 12 is a diagram illustrating an example of a signal for data transfer in the high-speed mode. In the high speed mode, first, similarly to the low speed mode, the output of the first handshake output terminal 125c is set to the L level by the camera body 100 (T81). In response to this, the photographic lens 200 sets the output of the second handshake output terminal 240g to L level and starts preparation for data transfer.

  When preparation for data transfer is completed (T82), the photographic lens 200 outputs a clock signal for 8 clocks from the clock output terminal 240b. The camera body 100 transmits 1-byte control data, which is a lens identifier request, to the photographing lens 200 in accordance with this clock signal. The control data is transmitted by outputting the data signal 71 from the first data output terminal 125d as in the low-speed mode. When the output of the data signal is completed, the output of the first handshake output terminal 125c is returned to the H level.

  Upon receiving the data signal 71, the taking lens 200 recognizes that the lens identifier request has been transmitted, and prepares for transmission of the lens identifier. When the transmission preparation is completed (T82), the clock signal is output from the clock output terminal 240b by the size of the lens identifier, and the data signal 72 representing the lens identifier is output from the second data output terminal 240e. When the output of the data signal is completed (T83), the output of the second handshake output terminal 240g is returned to the H level.

  Thereafter, as shown in FIG. 4B, the camera body 100 compares the received lens identifier with the stored lens identifier stored in the flash memory 142. If the two lens identifiers do not match, the camera body 100 requests lens data from the photographing lens 200 and stores the received lens data in the flash memory 142. Hereinafter, transfer of lens data and body data will be described with reference to FIG.

  When transferring body data and lens data, the output of the first handshake output terminal 125c is set to L level by the camera body 100 as in the case of receiving the lens identifier (T84). In response to this, the photographic lens 200 sets the output of the second handshake output terminal 240g to L level and starts preparation for data transfer. The photographic lens 200 that has completed preparation for data transfer outputs a clock signal that matches the size of the control data from the clock output terminal 240b (T85). A data signal 73 indicating a lens data request is output from the camera body 100 and a data signal 74 indicating a body data request is output from the photographing lens 200 according to the clock signal.

  The camera body 100 and the photographing lens 200 that have received the request each output body data and lens data in accordance with a clock signal output thereafter. Unlike the low-speed mode, the data signals 75 and 76 are all transmitted without interruption. That is, burst transfer is performed in data transfer in the high-speed mode. As described above, data transfer at a higher speed is performed in the high speed mode than in the low speed mode. Note that the communication for transferring only one of the lens data and the body data is also executed in the same manner as in FIG.

According to the camera body and the photographing lens according to the above-described embodiment, the following operational effects can be obtained.
(1) When a power-on operation is performed on the camera body 100, the camera body 100 receives a lens identifier included in the taking lens 200 and compares it with a lens identifier stored in the flash memory 142. If the comparison result does not match, the lens data is received from the photographing lens 200. Thereby, when the lens data of the photographing lens 200 is stored in the flash memory 142, the startup time of the camera body 100 is shortened.
In addition, according to the present embodiment, lens data (fixed data) having a large amount of data is transmitted by a communication method capable of performing high-speed data communication, so that waiting time during lens data transfer can be reduced. Can do.
Further, according to the present embodiment, the data amount is not so large (state data expressed as an index value), but other data other than the state data (the moving amount and moving direction of the focus lens are shown in real time). (Data) communication path must be secured separately (during shooting operation), the status data communication path is not dedicated to one direction but is also used as a communication path for the control command from the camera body 100 Since the method is adopted, state data communication and separate data communication can coexist without increasing the number of communication channels.

(2) When the lens identifier received by the camera body 100 matches the lens identifier stored in the flash memory 142, the main CPU 137 uses the lens data stored in the flash memory 142 and the lens 200 and The ASIC 135 is controlled, and if they do not match, the photographic lens 200 and the ASIC 135 are controlled using the lens data received from the photographic lens 200. As a result, lens data corresponding to the attached photographing lens 200 is always used, and there is no error in lens data.

(3) The camera body 100 stores the lens data received from the photographing lens 200 in the flash memory 142 immediately after reception. Accordingly, since the lens data corresponding to the photographing lens 200 is always stored in the flash memory 142, it is not necessary to receive lens data from the photographing lens 200 again until the photographing lens 200 is replaced.

(4) When the photographic lens 200 is attached when the camera body 100 is in the power-off state, the communication unit 125 can communicate with the photographic lens 200 and can be in a communicable state in which lens data can be written into the flash memory 142. Transition. Then, the lens data received by the communication unit 125 is written into the flash memory 142, and the power is turned off again. As a result, power consumption can be suppressed, and the user is not conscious of transmitting / receiving lens data.

(5) Communication between the camera body 100 and the photographing lens 200 includes communication in a high-speed mode and communication in a low-speed mode. The former allows higher-speed communication than the latter. Thereby, large data can be transferred in the high-speed mode, and the data transfer time can be shortened.

(6) The communication units 125 and 240 have two communication modes (a high-speed mode and a low-speed mode). When the camera body 100 receives lens data, communication is performed in the high-speed mode. On the other hand, when the camera body 100 receives data from the photographic lens 200 while controlling the operation of the photographic lens 200 (a period during which the communication line needs to be used for both transmission and reception). In order to reduce the burden (communication time) even in the low-speed mode communication, the data from the photographing lens 200 is converted into index value data that can reduce the data amount as compared with the data indicating the normal lens state as it is, Communicate as status data. Thereby, the time required for communication can be shortened.

(7) The camera body 100 receives lens data in the high-speed mode according to the attachment of the taking lens 200. Thereby, when imaging, it is not necessary to transfer lens data with a large amount of data, and the time required for communication can be shortened.

(8) The camera body 100 compares the lens identifier received from the photographic lens 200 with the lens identifier recorded in the flash memory 142, and transfers lens data in the high-speed mode only when they do not match. Thereby, as long as the lens data corresponding to the photographing lens 200 is recorded in the flash memory 142, it is not necessary to transfer the lens data, and the time required for communication can be shortened.

(9) In the high speed mode and the low speed mode, the terminal to be used is switched and the communication path is switched by the switch. Thereby, full-duplex communication can be performed without increasing the number of contacts prepared in the connection units 109 and 202.
(10) One of the communication paths used as a communication path (contact point) for communicating the focus adjustment state of the photographing lens 200 (a pulse signal indicating the moving amount and moving direction of the focus lens) from the photographing lens 200 to the camera body 100. Since the unit (transmission line 34a) is also used as a communication path for transferring fixed data (one-way communication path from the photographing lens 200 to the camera body 100 in the high-speed mode), compared with the conventional system Full duplex communication can be performed without increasing the number of contacts.
(11) In the present embodiment, a preparation completion signal issued by the photographing lens 200 in response to a request signal (request) from the camera body 100 is used in combination with a synchronous clock signal used during data communication. The number of terminals can be suppressed.
(12) Since the photographic lens 200 is configured to emit a clock signal, when the photographic lens side wants to interrupt data communication by itself, the photographing lens 200 voluntarily stops the output of the clock signal. Communication can be interrupted. This eliminates the need for providing a dedicated terminal for the photographing lens 200 to spontaneously interrupt communication. With this configuration, for example, when an operation stop button (not shown) for forcibly stopping communication provided on the photographic lens 200 side is operated while the photographic lens 200 is transmitting lens data. Since communication can be interrupted, etc., it is convenient for the user.
When it is desired to voluntarily interrupt communication on the camera body side, the handshake signal output from the first handshake output terminal may be switched from the Low level to the High level.

-Second embodiment-
Unlike the first embodiment, the camera body and the photographic lens in the second embodiment do not adopt a communicable state. Instead, the communication control unit 128 enables the communication unit 125, the main CPU 137, the memory 141, and the flash memory 142 so that communication between the camera body 100 and the photographing lens 200 and reading / writing of the flash memory 142 are possible even when the power is off. Is supplied with power.

  That is, the camera body according to the present embodiment has a transition to a communicable state in step S12 and a power-off state in step S15 in the flowchart showing the processing when the photographing lens is attached in the power-off state shown in FIG. The transition to is not performed. This is because the lens data transmission / reception processing shown in FIG. 8 can be performed even in the power-off state.

According to the camera body and photographing lens according to the second embodiment described above, the following operational effects can be obtained in addition to the operational effects obtained with the camera body and photographing lens according to the first embodiment.
(1) Even when the camera body 100 and the photographing lens 200 are in a power-off state, the communication unit 125 communicates with the photographing lens 200 and supplies power that can at least write lens data to the flash memory 142. This prevents the user from being aware that lens data has been transmitted and received.

(2) The power supply control circuit 128 only needs to manage two power supply states, that is, a power-off state and a power-on state. As a result, the control of the power supply state is facilitated, and the circuit scale of the power supply control circuit 128 can be 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.
(1) When the camera body 100 is in the power-off state, communication or the like may not be performed even if the photographing lens 200 is attached. In this case, the lens data of the newly attached photographic lens 200 is transferred when the camera body 100 is turned on.

(2) The detection that the photographing lens 200 is attached may be performed by means other than a mechanical switch (not shown). For example, a terminal that is energized when the photographing lens 200 is attached may be prepared, and the attachment of the photographing lens 200 may be detected by monitoring the voltage at this terminal.

(3) Even when a conversion lens is mounted between the camera body 100 and the photographing lens 200, the present invention can be applied. In this case, the lens identifier and the lens data are transferred when both the photographing lens 200 and the conversion lens are attached. In addition, the effect on the optical characteristics due to the attachment of the conversion lens may be that the conversion lens corrects the lens data according to the optical characteristics of the imaging lens 200 when transmitting the lens data to the camera body 100. The correction data reflecting the optical characteristics of the conversion lens may be transmitted to the camera body 100 independently of the lens data, and the camera body 100 may correct the lens data using the correction data. Note that the lens data output from the photographing lens 200 is once transmitted to the conversion lens regardless of whether correction is performed. The conversion lens may transmit lens data to the camera body 100 through a through terminal from the photographing lens 200.

(4) In the above embodiment, in the low speed mode, data representing the movement amount and direction of the focus lens is transmitted using the communication path 34 (FIG. 4). You may make it forward using. Further, a signal other than a pulse signal may be output from the photographing lens 200 to the communication path 34.

(5) The lens data received by the camera body 100 may be written to the flash memory 142 at a timing other than immediately after the lens data is received. For example, the lens data received last may be written to the flash memory 142 when the camera body 100 is turned off.

(6) When the camera body 100 receives the lens identifier, communication in the low speed mode may be used instead of communication in the high speed mode. In this case, when the received lens identifier does not match the lens identifier recorded in the flash memory 142, the camera body 100 shifts to the high speed mode and transfers lens data.
(7) In the above-described embodiment, the cycle of the clock signal output from the clock output terminal 240b is the same in both the high speed mode and the low speed mode. However, the clock cycle in the high-speed mode may be changed and controlled at a higher speed than the clock cycle in the low-speed mode.
(8) In the above-described embodiment, the clock signal is output only from the photographing lens 200 side. However, the camera body 100 side may be configured to generate the clock signal. In this case, the clock signal output from the photographing lens 200 is used when communicating from the photographing lens 200 to the camera body 100, and the clock signal output from the camera body 100 is used when communicating in the reverse direction. It ’s fine. In this case, the clock signal communication line (transmission line, terminal) can be used between the clock signal from the photographic lens side and the clock signal from the camera body side to reduce the number of terminals ( This is desirable from the viewpoint of downsizing of the apparatus. When they are also used, they are switched in time series.
(9) In the above embodiment, the lens-side CPU 231 switches the communication mode of the communication unit 240 of the photographing lens 200 in response to a communication mode switching command from the camera body 100. However, the lens-side main CPU 231 is switched. May actively switch the communication mode. In this case, as an example, means for detecting that the photographing lens 200 is attached to the camera body 100 or that the power supply on the camera body side is turned on (for example, attachment when power supply from the camera body side is started, Alternatively, a circuit means for detecting that the power of the camera body is turned on is provided on the photographing lens side, and when these are detected, the main CPU 231 sets the communication unit 240 to the high speed mode and outputs lens data. Then, the main CPU 231 may set the communication unit 240 to the low speed mode.

  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. .

100 Camera body 125 Communication unit (camera body)
137 Main CPU (camera body)
200 Shooting lens 231 Main CPU (shooting lens)
240 Communication unit (photographing lens)

Claims (17)

A mounting means for detachably mounting a photographic lens capable of outputting lens data which is fixed data determined for each photographic lens and state data representing the state of the photographic lens;
A communication unit that operates by switching between a first communication mode and a second communication mode that is different from the first communication mode, and that transmits and receives data to and from the photographing lens;
Control means for performing control based on the lens data and the state data received by the communication means,
The image pickup apparatus, wherein the communication means operates in the first communication mode when receiving the lens data, and operates in the second communication mode when receiving the state data. The imaging device according to claim 1,
The imaging apparatus according to claim 1, wherein the first communication mode performs communication in a communication mode in which a time required for data transfer is shorter than that in the second communication mode. The imaging device according to claim 2,
The communication means includes a first communication path and a second communication path,
When the communication means operates in the first communication mode, the first communication path is used for transferring the lens data from the photographing lens to the imaging device,
The imaging apparatus, wherein when the communication unit operates in the second communication mode, the second communication path is used to transfer the state data from the imaging lens to the imaging apparatus. The imaging device according to claim 3.
The first communication path is a communication path used for one-way communication from the photographing lens to the imaging device,
The second communication path is a communication path used for bidirectional communication between communication from the photographing lens to the imaging device and communication from the imaging device to the photographing lens;
In the second communication mode, the communication direction of the second communication path is switched in time series. The imaging apparatus according to claim 4,
In the first communication mode, the second communication path is used as a one-way communication path from the imaging apparatus to the photographing lens. In the imaging device according to any one of claims 1 to 5,
The communication means includes
The operation according to the first communication mode is performed according to the attachment of the photographing lens to the attachment means,
After receiving the lens data, an image pickup apparatus capable of operating in the second communication mode. The imaging device according to claim 6,
Storage means capable of storing different lens identifiers for each photographic lens output by the photographic lens;
Determination means for determining whether or not the lens identifier received by the communication means matches the lens identifier stored in the storage means;
The imaging apparatus according to claim 1, wherein the communication unit performs an operation in the first communication mode when the determination unit makes a negative determination. In the imaging device according to any one of claims 3 to 5,
When the communication means operates in the second mode, the first communication path is used to transfer other data different from the lens data and the state data from the photographing lens to the imaging device. An imaging device that is characterized. A photographic lens that is detachably attachable to an imaging device and can output lens data, which is fixed data set for each photographic lens, and status data representing the state of the photographic lens,
A communication unit that operates by switching between a first communication mode and a second communication mode that is different from the first communication mode, and that transmits and receives data to and from the imaging device;
The photographic lens, wherein the communication means operates in the first communication mode when transmitting the lens data, and operates in the second communication mode when transmitting the status data. The photographic lens according to claim 9,
The photographic lens, wherein the communication means operates by switching the communication mode in accordance with a signal transmitted from the imaging device to the photographic lens. The photographic lens according to claim 9 or 10,
The first communication mode performs communication in a communication mode in which a time required for data transfer is shorter than that in the second communication mode. The photographing lens according to any one of claims 9 to 11,
The communication means includes a first communication path and a second communication path,
When the communication means operates in the first communication mode, the first communication path is used for transferring the lens data from the photographing lens to the imaging device,
An imaging lens, wherein when the communication unit operates in the second communication mode, the second communication path is used to transfer the state data from the imaging lens to the imaging device. The photographic lens according to claim 12,
The first communication path is a communication path used for one-way communication from the photographing lens to the imaging device,
The second communication path is a communication path used for bidirectional communication between communication from the photographing lens to the imaging device and communication from the imaging device to the photographing lens;
In the second communication mode, the photographing direction of the second communication path is switched in time series. The taking lens according to claim 13,
In the first communication mode, the second communication path is used as a one-way communication path from the imaging device to the photographing lens. In the taking lens according to any one of claims 9 to 14,
The communication means includes
The operation according to the first communication mode is performed according to the attachment of the photographing lens to the imaging device,
After the lens data is transmitted, the photographing lens can be operated in the second communication mode. The taking lens according to claim 15,
The communication unit is configured to determine a lens identifier that is different for each photographing lens before transmitting the lens data to the imaging device in order to cause the imaging device to determine whether or not to transmit the lens data to the imaging device. In addition, the photographic lens is transmitted to the imaging device.   The photographic lens according to any one of claims 9 to 16, wherein the state data is index data that indicates a simplified state of the photographic lens.

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