JPH0782181B2 - Interchangeable camera - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a system for exchanging data between a camera body and a plurality of accessories (for example, an interchangeable lens or an intermediate lens), which is performed via electrical contacts.

(Background of the Invention) Several systems for transmitting and receiving serial data have been recently announced in order to efficiently receive various kinds of lens information. For example, there is a disclosure such as JP-A-59-188622. This system includes the camera body, interchangeable lens, and intermediate accessories that are used by inserting it in the middle, but it consists of a terminal for starting data transfer, a clock pulse terminal, and a terminal for outputting data. There is. When the intermediate accessory is used, the lens data is transmitted to the camera body side through the arithmetic circuit of the intermediate accessory, and when the intermediate accessory is used, it takes time for the camera body side to receive the data. Not only did it take a lot of time, but the configuration of the intermediate accessories became complicated.

The present invention is intended to solve these drawbacks and to realize a method for exchanging data between a plurality of accessories and camera bodies with a simple configuration.

(Summary of the Invention) The present invention relates to a first accessory terminal used for starting (accessing) data communication with a microcomputer incorporated in a first accessory, and a microcomputer incorporated in a second accessory. It is characterized in that a second accessory terminal used for starting (accessing) data communication is provided independently. As a result, in the present invention, it is possible to immediately perform data communication with the accessory microcomputer without performing the check communication for identifying the type of the accessory in which the microcomputer on the camera body side is mounted. Etc. can be shortened.

(Embodiment) FIG. 1 is a block diagram of an embodiment of the present invention. 1 is a camera body, 2 is an interchangeable lens (a lens that can be auto-focused), and 3 is an intermediate accessory (an accessory that cannot be auto-focused by itself). The camera body 1 performs automatic exposure control and automatic focus adjustment. The camera body 1 includes a microcomputer (hereinafter referred to as MCU) 10, an automatic exposure control unit 11, a focus detection unit 12, a motor drive unit 13, a motor 14, and a cutter puller 15. With this configuration, data can be exchanged with the interchangeable lens 2 or the intermediate accessory 3 via the electrical contacts 1a to 1f. Power switch SW1
Is a switch that is closed by half-pressing the release button, etc. By closing the switch, the power supply V ₁ on the camera side is supplied to the entire circuit of the camera body 1 and the power supply terminal 1a Power is supplied to the interchangeable lens 2 and the intermediate accessory 3 via the. Exposure control unit 11 is MC
U10 controls the known exposure control process, and the MCU 10 determines the driving direction of the motor 14 according to the output of the focus detection unit 12 and outputs the driving signal to the driving circuit 13 so that the cutting puller 15 Control the rotation of. Cutler 15
Is engaged with the lens attached to the camera body 11 and the coupler of the intermediate accessory (teleconversion lens, etc.), and the automatic focusing is performed by moving the optical system (A
F). The MCU 10 is a well-known microcomputer having a serial interface. The serial clock terminal SCLK is connected to the electrical contact 1c, and the serial output terminal SO and the serial input terminal SI are connected to each other to the electrical contact 1d. Input / output terminal P ₁₁ is connected to electrical contact 1b, and input / output terminal P ₁₂ is connected to electrical contact 1e, electrical contact 1f
Is the ground terminal.

Interchangeable lens barrel (shooting lens) 2 is MCU 20, optical system 2
1 and a kuppler 22. The cutter 22 engages with the cutter 15 of the camera body 1 or the cutter 33 of the intermediate accessory 3 to move the optical system 21 to a position (focus position) determined by the output of the focus detection unit 12 of the camera body 1. do. The MCU20 has the same serial interface as the MCU10. The serial clock terminal SCLK connects to the electrical contact 2c and the serial input terminal SI.
And serial output terminal SO are connected to each other and electrical contact 2d
, And the input / output terminal P ₂ is connected to the electrical contact 2b, respectively. Further, the electric contact 2a serves as a power supply terminal, the power supply voltage V ₁ on the camera side is applied to the MCU 20, and the electric contact 2f serves as a GND terminal.

Intermediate accessory 3 is MCU 30, optical system 31, cutler 3
2 and a kuppler 33. The optical system 31 functions to convert the focal length of the interchangeable lens 2 to a long focus if the intermediate accessory 3 is a teleconversion lens, and if the intermediate accessory 3 is an intermediate ring or the like, the lens itself does not exist and the optical path length is simply It only grows. Katsu puller
The reference numeral 32 is connected to the cutler 33, and the cutler 32 engages with the cutler 15 and the cutler 33 engages with the cutler 22 to transmit the mechanical rotation amount of the cutler 15 of the camera body 1 to the cutler 22 of the lens 2.
The MCU 30 is equivalent to the MCU 20 and has the same serial interface function as the MCU 10. The serial clock terminal SCLK is connected to the electrical contact 3c, and the serial input terminal SI and the serial output terminal SO are connected to each other to form the electrical contact 3d.
, And the input / output terminal P ₃ is connected to the electrical contact 3e, respectively. The electrical contact 3a is a power supply terminal for supplying power to the MCU 30 by connecting to the power supply terminal 1a on the camera 1 side, and is also connected to the electrical contact 3a ', and the interchangeable lens 2 is connected via the electrical contact 2a. Relay power to. Electrical contacts 3b is connected directly to the electrical contact 3b not connected to the MCU 30 ', to transmit the output of the P ₁₁ terminal of MCU10 via electrical contacts 2b. The electrical contacts 3c and 3d are connected to the electrical contacts 3c 'and 3d', respectively, and the electrical contacts 2c and 2d are connected to the camera body 1. Electrical contact 3f is 3f ′
Are connected, and the ground (GND) of the camera body 1 and the interchangeable lens 2 is made common.

FIG. 2 is a block diagram showing another intermediate accessory mounted on the camera 1. Reference numeral 4 is an intermediate accessory (teleconversion lens capable of automatic focus adjustment) and 5 is an interchangeable lens (lens which cannot be automatically adjusted by itself), both of which are used in combination with the camera body 1 shown in FIG. Intermediate accessory 4 is MCU 40, optical system 4
It consists of 0, and a kuppler 42. Optical system 41
Has the same function as the optical system 31 shown in FIG. The cutler 42 engages with the cutler 15 of the camera body 1, and the optical system 41 is moved according to the rotation amount thereof to perform automatic focus adjustment. The MCU 40 is basically the same as the MCU 30, except that the contacts (3a 'to 3f' in FIG. 1) for transmitting the electrical contacts on the camera body side to the interchangeable lens side and the coupler for transmitting the rotation amount (first 33) is different from the intermediate accessory 3 shown in FIG.

The interchangeable lens 5 is a conventional lens (that is, a lens that cannot perform automatic focus adjustment) that does not have a member that engages with the cutler 15 of the camera body 1, and is mainly composed of only the optical system 51, and is manually operated by a conventional focusing ring. Then, the lens 51 is moved to adjust the focus.

With the above structure, not only the interchangeable lens 2 or 5 can be directly attached to the camera body 1, but also the intermediate accessory 3 or 4 can be inserted in the middle.

Each electrical contact (1a ~ 1f, 2a ~ 2d, 2f, 3a ~ 3f,
3a'-3d ', 3f', 4a, 4c-4f) are arranged in the circumferential direction of the lens mount (not shown), and the accessory 3, 4 or lens 2 is attached to the camera 1 or the intermediate accessory 3. Sometimes the same subscript (Alphabet)
The contacts indicated by are arranged so as to be opposed to each other.

When the intermediate accessory 4 is inserted between the interchangeable lens 2 and the camera body 1, the electric signal on the camera body 1 side and the rotation amount of the cutter 15 cannot be transmitted to the lens 2 side. Has only the same function as the interchangeable lens 5.

FIG. 3 is a timing chart for explaining the function of the embodiment shown in FIG. And MCU 10 and MCU respectively
The waveforms are output from the 20 input / output terminals P ₁₁ and P ₂ , and both are configured as pull-up resistors + open drains in the output state, so that both terminals have electrical contacts 1b, 2b or 3b, 3b. When the output of either P ₁₁ or P ₂ is L, the signal of both terminals becomes L and becomes a composite output as shown below, and each terminal receives in the input state. It becomes a waveform. Is the output waveform of the serial clock terminal SCLK of the MCU10 and becomes the serial clock input of the MCU20 or MCU30 by being connected to the terminal SCLK of the MCU20 or 30 via the electrical contacts 1c, 2c, 3c, 3c '. .
, Are output waveforms of the serial output terminals SO of the MCUs 10, 20, and 30, respectively. Each terminal SO has a pull-up resistance + open drain configuration, so when they are connected to each other through electrical contacts 1d, 2d, 3d, 3d ', a combined output as shown at each terminal SO is obtained. . The output of each terminal SO is also connected to the respective serial input terminals SI of the MCUs 10, 20, 30 and becomes the respective serial inputs. Are the waveforms output from the input / output terminals P ₁₂ and P _{3 of the} MCU 10 and MCU 30, respectively, and when both terminals are connected via the electrical contacts 1e and 3e, both terminals P ₁₂ and P ₃ Similar to, a composite output like is obtained, which is connected to the respective terminals P ₁₂ , P ₃
Is the waveform received in the input state.

FIG. 4 is a flow chart of a subroutine for inputting / outputting serial data of the MCU 10. P ₁₁ or P ₁₂ can be accessed by setting the variable j to 1 or 2 beforehand. FIG. 5 is a flow chart of the MCU 20, 30, or 40. The variable i is determined by the MCU 20, 30, 40, and the data of the lens or the intermediate accessory on which the variable i is mounted is stored in the MCU 20, 30, 40. Enables output.

Table 1 shows the contents of the ROM provided in the MCU 20, and the lens 2 is an example of a 50 mm F1.8 lens. Data $ 50 indicating the focal length (where $ indicates a hexadecimal number) is stored in address 0 of the ROM of the MCU20. No. 1 is a spare with $ 00.
The data $ 14 indicating the open aperture value is contained in the second address.
F1.8 lens open aperture value So, 1/12 EV step is 20 steps,
It is $ 14 when expressed in hexadecimal. Also, the minimum aperture is F22 (A
V9), the maximum number of steps to narrow down In the same way, 1/12 EV step is 88 steps, so it is $ 58 in hexadecimal. This is number 3. At address 4, lens type information, that is, identification information as to whether or not the lens can be driven by the cup puller is entered. In this case, since the lens 2 can be transmitted with the rotation of the cutter of the camera body, only the most significant bit (bit 7) of the data of 8 bits is set to 1 and $ 80 is inserted. An AF control amount (for example, a value indicating the relationship between the defocus amount and the movement amount of the optical system 21) is entered at addresses 5 to 7. It is possible to further add data (for example, a value relating to the aberration amount of the optical system 21) to the 8th address onward, but it is omitted here.

Table 2 shows the contents of the ROM provided in the MCU 30, and is an example in the case of a so-called teleconverter in which the intermediate accessory 3 doubles the focal length of the lens. Data of $ 00 is stored as a spare at addresses 0 and 1. The open aperture value change amount enters at address 2. In case of 2x teleconverter, 2
It will be darker by one step, so 1/12 EV step will be 24 steps,
Hexadecimal number $ 18 of data will be entered at address 2. The data of effective open aperture value is entered in the address 3. This teleconverter Even if a brighter lens is attached, it will not get brighter than that due to vignetting, so I expressed it in 1/12 EV step and put $ 14.

At address 4, accessory type information, that is, identification information as to whether or not the accessory can be driven by a cutter is entered. Since the type of the intermediate accessory 3 can transmit the rotation of the cutter of the camera body, the highest bit (bit 7; lowest bit is 0) of 8 bit data is set to 1 and connected to the electrical contact on the lens side. Terminal
In order to show that there are 3a ', 3b' to 3d ', 3f', the bit 6 is set to 1, and the rotational force for moving the optical system 21 of the lens 2 by the cup pullers 32 and 33 can also be transmitted. By setting bit 5 to 1 to represent, $ EO
No. 4 data will be entered. A conversion coefficient for AF (for example, a coefficient for correcting the above-mentioned AF control amount when an accessory is attached) is placed at addresses 5 to 7. MCU10 is 5 of lens 2
A predetermined calculation is performed based on the AF control amount and the AF conversion coefficient stored at address 7, the control amount when the accessory is combined with the lens is determined, and the predetermined automatic focus adjustment is performed.

Table 3 shows the contents of the ROM provided in the MCU 40, and is an example of a so-called teleconversion lens in which the intermediate accessory 4 doubles the focal length of the lens. When the optical system 41 is the same as that of the intermediate accessory 3, the same data is entered at addresses 0 to 3. Information on the accessory type is entered at address 4, but it is specified in the same format as the intermediate accessory 3. Unlike the case shown in Table 2, the bit 7 is 1 because the intermediate accessory 4 transmits the rotation of the camera puller 15 on the camera body side, but the bit 7 cannot be connected to the lens side because electrical contact and rotation amount cannot be connected. 6, 5 will be 0, and eventually $ 80 will go to No. 4. Although the control amount for AF is entered at addresses 5 to 7, the most appropriate value is entered when the optical system of the lens 5 is predetermined and used in combination.

Now, the timing chart of FIG. 3 will be described. The camera body MCU 10 needs information from an interchangeable lens or an intermediate accessory in the process of its main routine (not shown). Therefore, at this time, before entering the subroutine of FIG.
Is set to 2, the state in which the input / output terminal P ₁₂ is used is set, and the subroutine processing is started. Step # 10 in Figure 4
At 1, the input / output terminal P ₁ j, that is, P _{12 is set} to the output state, and the output of L from P ₁₂ activates the serial data transfer shown in FIG. Here, P ₁ j is designated as P ₁₂ until changed later. Then,
When t = t ₁ , the output of P ₁₂ shown by changes from H to L. In this case MCU 30 after power-on reset, or step # after treatment 9 and summer the state of step # 1, (in the case of MCU 30 Pi = 3) input and output terminals P ₃ and excisional input state, P ₃ Monitor whether the input is L or not. If it is H, the process of step # 1 is repeated, and if it is L, the process can proceed to step # 2. Since the input / output terminal P _{3 of the} MCU 30 is now observing the waveform of P ₁₂ output and synthesized, it is possible to proceed to step # 2 when t = t ₁ . In step # 2, the SO terminal is set to a high impedance state so as not to affect the SI input, the input / output terminal P ₃ is changed to the output state and L is output from P ₃ (t = t ₂ ),
Indicates that it is ready. After the processing of Step # 101, the MCU10 transfers the address data stored in the memory of the MCU10 to the serial input / output register of the MCU10 in Step # 102, measures the predetermined time in Step # 103, and returns the response (L level) of the MCU30. Output), and then input / output terminal P ₁₂ to H
(T = t ₃ ). In step # 104, the MCU 10 sets the input / output terminal P ₁₂ to the input state and monitors whether P ₁₂ is L or not. If P ₁₂ is H, the process of step # 104 is repeated, and if it is L, the process proceeds to step # 105 to start the serial clock (t = t ₄ ). Before starting the subroutine, MCU10 is $ 0 of the intermediate accessory 3 in the main routine.
If the change in the open aperture value stored in the address 2 is required, $ 02 is stored as address data in the memory of the MCU 10 described above. Therefore, from the time t ₄ onward, in synchronization with the serial clock output of the MCU 10 shown in FIG. 3, as shown from the serial output terminal SO of the MCU 10,
The address data is output as 01000000 from the least significant bit (LSB). During this time, the MCU 30 monitors the flag that becomes 1 when the serial clock is input to the terminal SCLK for 8 pulses in step # 3. The process is repeated, and at t = t ₅ when 8 pulses are input, the process proceeds to step # 4 to set the terminal P ₃ to H and the input / output terminal P ₁₂ to H (t = t ₆ ). In step # 5, the data of the serial input / output register of the MCU 30 is transferred to the X register of the MCU 30. Data that this is stored in the serial input and output registers, the composite output because SO terminals of t = t ₄ during which at that output from SO terminal of MCU10 during ~t ₅ MCU 20 and MCU30 is decreased to the high-impedance The MCU30 S
The data of 01000000 from the LBS, that is, 00000010B (B represents a binary number) when expressed from the most significant bit (MBS) is also transferred to the X register in the I terminal.
In step # 6, the MCU30 specified by the X register
The data at address $ 02 is transferred to the serial input / output register of MCU30.

Since the data of Table 2 is stored in the MCU 30, $ 18 is the data. And outputs the L from the output terminal P ₃ to indicate that the transfer preparation in step # 7 is complete (t = t _7).
On the other hand, the MCU 10 processes Step # 105 and then executes Step # 106.
At t = t _{6 and} thereafter, after the input / output terminal P ₃ becomes H, the input / output terminal P ₁₂ becomes L at step # 107.
Monitor whether or not. If the P ₁₂ terminal is H, the process is repeated as it is, and the P ₃ output (waveform) of the MCU 30 is H →
When L, the waveform of is input to the P ₁₂ terminal of the MCU 10, so that the MCU 10 can proceed to the next step. Step # by excisional the serial output terminal SO of 108 in MCU10 a high impedance state, to start the serial black poke from the SCLK terminal (, t = t _8). Then, in synchronization with the serial clock, this time from the SO pin of the MCU30, the MCU30
$ Stored in the serial I / O register of step # 6
The 18 data, that is, the data of 00011000B expressed in binary number is output one bit at a time from the LSB. This output is M
Input to the serial input terminal SI of the CU10 with the waveform of and input the data of 00011000B to M in synchronization with the serial clock.
Input one bit from LSB to the serial input / output register of CU10. In step # 109, the MCU 10 monitors the completion of the serial transfer by the flag which becomes 1 by the input of 8 pulses of the serial clock in the same manner as the processing of step # 3 in the MCU 30. At t = t ₉ when the flag becomes 1,
After the transfer of the data of 00011000B, that is, $ 18, to the serial input / output register of the MCU10 is completed, the process proceeds to step # 110 to store the data of the serial input / output register in a predetermined memory of the MCU10. By the above processing, the serial data input / output subroutine processing for the intermediate accessory 3 of the MCU 10 is completed, and the information of $ 18 is received as the data of the address $ 02. After the processing of step # 7, the MCU 30 monitors the completion of the serial transfer in step # 8 in the same manner as in step # 3, and when completed, proceeds to step # 9 to set the serial output terminal SO to high impedance, After the serial data is sent and received between the lenses so as not to affect other accessories, the input / output terminal P _{3 is set} to H (t = t ₁₀ ), and the process returns to step # 1. After that is in the input state of the input and output terminals P _3, MC
The composite output () obtained by the P ₁₂ output of U10 becomes L, and the activation of the transfer of serial data is monitored. In this state, serial I / O pin SO I / O pin
Since P ₃ is at high impedance or H level, serial data is exchanged between the body and the lens (when the accessory 3 is attached to the body 1 and the lens 2 is further attached to this accessory 3). Sometimes it has no effect.

The MCU 20 from t = t ₁ to t = t ₁₀ is different from the MCU 30 in step #
Since I / O terminal P ₂ is being monitored in 1
Since there is no activation of serial data transfer via the I / O terminal P _11, the process of step # 1 is repeated and the standby state is entered. However, since the serial output terminal SO of the MCU 20 is in high impedance, It does not affect the exchange of data between intermediate accessories.

Now, in the case of the present embodiment, the MCU 10 of the camera body must receive the change amount of the open aperture value by the input / output subroutine processing for the intermediate accessory 3 and then receive the data of the open aperture value from the interchangeable lens. Since the data of the open aperture value is stored in the address $ 02 as shown in Table 1, the address data of $ 02 may be sent to the interchangeable lens and processed in the same manner. Unlike the case for the intermediate accessory described above, the MCU 10 sets the variable j to 1 this time, and enters the serial data input / output subroutine processing of FIG. Then, since the input / output terminal P ₁₁ is to be specified this time, it is necessary to activate the transfer of serial data to the P ₂ terminal of the MCU 20 connected via the electrical contacts 1b, 3b, 3b ′, and 2b. Is possible (t = t ₁₁ ).

The subsequent sequence is basically the same as that for the intermediate accessory 3. P treatment of MCU10 from the P ₁₂ terminal
It moves to ₁₁ terminals, and the MCU20 of the interchangeable lens 2 answers instead of the MCU30. t = t _{11 to} t = t ₂₀
Corresponds to the sequence from t = t _{1 to} t = t ₁₀ . Details are omitted, but if address data of $ 02 is sent, t =
t ₁₈ ~t between ₁₉ in synchronization with the serial black poke () MCU 2
The serial output terminal SO of 0 outputs 00101000 from the LSB. If this data is rewritten from the MSB, it becomes 00010100B, that is, $ 14, and is stored in a predetermined memory of the MCU10.

Through the above process, the MCU 10 receives $ 14 from the lens as the maximum aperture value and $ 18 from the intermediate accessory as the amount of change in the maximum aperture value.

Both of these data are expressed in 1/12 EV steps, so the MCU10 calculates the following calculation for the $ 14 + $ 18 = $ 2C lens and the intermediate accessory (in this case, the teleconversion lens). It is possible to obtain a synthetic open aperture value.
$ 2C is 44 in decimal. Since it is 1/12 EV step data, it will be the contents of F3.5 of AV32 / 3 in the aspect value. The calculation result can be used, for example, for display control.

The timing chart of FIG. 3 describes the case where the interchangeable lens 2 and the intermediate accessory 3 are attached to the camera body 1 in combination, but when only the interchangeable lens 2 is attached, the timing chart in FIG. Electrical contacts 1a and 2
a, 1b and 2b, 1c and 2c, 1d and 2d, and 1f and 2f are connected, and the 1e contact is not connected to any contact on the lens side. Therefore, the variable j is set to 2 and the subroutine shown in FIG. 4 is entered. Then, at t = t ₁ , even if the MCU 10 sets the P ₁₂ terminal to L, the response of the MCU 30 at t = t ₂ (P ₃ terminal to L
Since) it is not dropping the P ₁₂ terminal to the L level, t
When the P ₁₂ terminal is set to H at the time point of = t _3, the P ₁₂ terminal is set to H and the processing of step # 104 is repeated. This is omitted from the flow chart shown in FIG.
At 104, a preset value is set in the timer in advance, and if the time when the process is repeated reaches a certain time or longer, the process exits the subroutine process of FIG. 4 for the intermediate accessory and the variable j is set to 1. Moving on to the subroutine processing (FIG. 4) for the interchangeable lens 2, t
= T _{11 to} t ₂₀ is performed.

When the intermediate accessory 4 of FIG. 2 is attached to the camera body 1, the electrical contacts 1a and 4a, 1c and 4c, 1d and 4d, 1e and 4e, and 1f and 4f are connected, respectively, and P _{11 of the} MCU 10 is connected. Nothing is connected to the electrical contact 1b connected to. Exchange of serial data between the camera body 1 and the intermediate accessory 4 is performed in the same manner as t = t ₁ ~t ₁₀ in the timing chart of FIG. 3. At the time of t = t _1, the MCU 10 activates the transfer of serial data by setting the P ₁₂ terminal to L (t =
t ₁ ), the corresponding intermediate accessory 4 receives it by the input / output terminal P _{4 of the} MCU 40, and responds by setting the P ₄ terminal to L at t = t ₂ . In the following sequence, the input / output terminal P ₄ of the MCU 40 follows the flow chart of FIG.
_{Take the} same action as in ₃ . That is, the SO terminal of the MCU 40 changes as shown in. The difference is that the content of data responding to the camera body 1 is different due to the difference in the characteristics of each intermediate accessory. Since the data shown in Table 3 is stored in the intermediate accessory 4, as shown in FIG.
When the 02 data is sent, it is the same as for the intermediate accessory 3 $
Send 18 data to camera body. Next, camera body 1
MCU 10 is trying to receive the information of the lens 5, and the variable j
Is set to 1 and the subroutine shown in FIG. 4 is entered. At t = t ₁₁ , nothing is connected to the electrical contact 1b even when the input / output terminal P _{11 is set} to L and the lens 5 is activated. Therefore, at t = t ₁₃ , the P ₁₁ terminal is set to H. If set to t
= Since no lowering in t ₁₂ from the lens side to the L level, P ₁₁ pins as an H level and repeats the processing of step # 104 of FIG. 4. Therefore, as described above, the process exits after a predetermined time, and the serial data input / output subroutine process (FIG. 4) with the lens is completed. Even if the intermediate accessory 4 and the interchangeable lens 2 are combined and attached to the camera body 1, the intermediate accessory 4 and the interchangeable lens 2 are not connected to the electrical contacts of the interchangeable lens 2, and therefore the same as the lens 5 having no electrical contact.

In the above description, the data at the address $ 02 in Tables 1 to 3 has been described, but the same processing as above is performed for the data at other addresses.

As described above, the camera body can not only easily read the necessary data from the lens, but also can easily read the data even if the intermediate accessory has various forms. Further, in FIG. 3, the data of the intermediate accessory and the data of the lens are read in order, but this is not always necessary, and the data may be read freely for each.

Note that when the intermediate accessory 4 is attached to the camera body 1, the MCU 10 sends $ 04 as address data and reads the accessory type data stored at the address $ 04. Since it is possible to identify in advance that it is not connected to the electrical contact on the lens side, it is possible to move to the next processing without starting the data reading for the interchangeable lens by the P ₁₁ terminal and shorten the processing time.

The data in Table 1 is for the 50 / 1.8 lens, but if the data changes with an encoder that changes depending on the focal length etc., such as a zoom lens, the data will be $ 04. If the lens type bit φ of the address is set to 1 and stored in advance, the MCU 10 can be identified. If a combination of a zoom lens with an encoder and an intermediate accessory without an encoder is attached to the camera body 1, in the case of an intermediate accessory, once the necessary data is read, there is no need to read it again. In the case of a zoom lens, the data may be constantly changed by the encoder, so the data reading must be repeated at least at a fixed period. In such a case, only the data reading of the interchangeable lens 2 can be repeated after the data reading of the intermediate accessory 3. On the other hand, even if the intermediate accessories have encoders, by setting the bit φ of the accessory type data at address $ 04 to 1 the MCU 10 can identify the data. After reading the necessary data from, only reading the data of the intermediate accessory may be repeated.

(Effect of the Invention) According to the present invention, a first accessory terminal used for starting (accessing) data communication with a microcomputer incorporated in a first accessory, and a microcomputer incorporated in a second accessory. The second accessory terminal used for starting (accessing) data communication with is independently provided.

With this configuration, when viewed from the camera microcomputer, the microcomputer of the first accessory and the second accessory can be independently accessed. Therefore, on the camera microcomputer side, the first accessory is mounted or the second accessory is mounted. Each time it is attached, it is immediately checked into the data processing corresponding to each accessory without checking based on the read data, the processing procedure of the camera microcomputer becomes smooth, and the processing speed is increased. be able to.
For example, if the accessory's access terminal for starting data communication is commonly used by multiple accessories, check which accessory is installed on the camera body side in the camera microcomputer. In order to do so, the check communication must be performed, and it takes time for the check communication before the serial data communication is started, which increases the time required for the data communication in the entire system. Therefore, the processing procedure becomes complicated.

[Brief description of drawings]

1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing another intermediate accessory, FIG. 3 is a timing chart showing serial data transfer according to this embodiment, and FIG. 4 is a camera body. The flow chart of the serial input / output processing subroutine of MCU1
This is a flow chart for processing common to the MCUs 20, 30, and 40. (Explanation of symbols of main parts) 1 ... Camera body, 2 ... Interchangeable lens, 3 ... Intermediate accessory, 4 ... Intermediate accessory, 5 ... Interchangeable lens, 10, 20, 30, 40 ... Microcomputer ( MC
U), 15, 22, 32, 33, 42 ... Cutler, 1a-1f, 2a
~ 2f, 3a ~ 3f, 3a '~ 3f', 4a ~ 4f ... electrical contact

Claims (2)

[Claims] 1. A camera having a camera microcomputer, wherein an accessory can be exchanged, and a first accessory having a first accessory microcomputer capable of communicating with the camera microcomputer can be mounted thereon, and the camera can be mounted. Mount for an accessory to which a second accessory equipped with a microcomputer for a second accessory capable of communicating with a microcomputer for use in the accessory is mounted, and the mount for the accessory is provided, and by mounting the first accessory, the microcomputer for the first accessory Data communication is performed between a computer and the camera microcomputer, and data communication is performed between the second accessory microcomputer and the camera microcomputer by mounting the second accessory. And a contact point terminal group for communication, wherein the contact point terminal group for communication is not used for (a) starting data communication with the microcomputer for the second accessory, and is used for data communication with the first accessory. The first accessory terminal used for starting and outputting an access signal to the first accessory microcomputer, and (b) used for starting data communication with the first accessory microcomputer. A second accessory terminal used for starting data communication with the second accessory and outputting an access signal to the second accessory microcomputer; and (c) the first accessory or the second accessory. One of the first accessory is mounted and is responsive to the access signal. Microcomputer or the second accessory microcomputer and accessories interchangeable camera, characterized in that it is composed of a data communication terminal that enables serial data communications between the microcomputer for the camera. 2. A first accessory is an interchangeable lens barrel capable of data communication, and a second accessory is an intermediate lens capable of data communication, to which an interchangeable lens not capable of data communication is mounted. Claim 1st
A camera with interchangeable accessories according to item.