JPH041331B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is for outputting a lens information signal to the camera body according to the characteristics of intermediate accessories such as a rear converter, an intermediate ring, and a bellows that are interposed between an interchangeable lens and a camera body. The present invention relates to an output device. (Prior art) Various unique information of the interchangeable lens, such as the maximum aperture value, focal length, and conversion coefficients for making the focus shift amount for automatic focus adjustment correspond to the driving amount of the focusing lens, etc., are obtained from the interchangeable lens. Information output devices that electrically transmit information to a camera body are already known. Conventionally, this type of device has been limited to cases where the interchangeable lens is attached directly to the camera body, and intermediate accessories such as a rear converter, intermediate ring, and bellows are interposed between the interchangeable lens and the camera body. No countermeasures had been considered for use. Generally, when an intermediate accessory such as a rear converter is inserted between the interchangeable lens and the camera body, the maximum aperture value and focal length become a composite value of the interchangeable lens and the intermediate accessory. There was a problem with exposure control, automatic focus adjustment, and display not functioning properly when using only one camera. As a device to solve this problem, JP-A-59-
The one shown in the publication No. 188622 has been proposed. This device is equipped with a calculation circuit that performs correction calculations according to the characteristics of the intermediate accessory itself on the unique information received from the interchangeable lens on the intermediate accessory side, and an output circuit that outputs the calculated information to the camera body. It is an intermediate accessory. However, this device requires an IC equipped with a correction calculation circuit according to characteristics for each intermediate accessory, resulting in high cost. However, since rear converters and the like are generally used as auxiliary tools, consumers demand cheaper ones, and cost problems remain. (Objective) An object of the present invention is to provide an information output device for an interchangeable lens that allows exposure control, automatic focus adjustment, and display to function normally even when an intermediate accessory is interposed between the interchangeable lens and the camera body. do. (Means for Solving the Problems) The present invention has been made to solve the above problems, and the first invention is that unique information based on electric signals of the interchangeable lens is electrically transmitted from the interchangeable lens to the camera body. In an interchangeable lens used in a camera system in which an interchangeable lens is used, the intermediate accessory interposed between the interchangeable lens and the camera body includes a detection means for detecting the type of the intermediate accessory from an electrical signal sent from the intermediate accessory, and a detecting means for detecting the type of the intermediate accessory interposed between the interchangeable lens and the camera body. It is equipped with a calculation means for performing a correction calculation on the unique information based on the electric signal of the interchangeable lens in accordance with the characteristics, and an output means for outputting the information calculated by the calculation means to the camera body. be. Further, a second invention provides, in the intermediate accessory interposed between the interchangeable lens and the camera body according to the first invention, information by an electrical signal indicating the type of the intermediate accessory to the interchangeable lens side circuit. The camera is configured to include output type information setting means and signal transmission means for directly transmitting the signal output from the information output device of the interchangeable lens to the camera body. (Example) The present invention will be explained below with reference to Examples. FIG. 1 is a block diagram showing an information output device for an interchangeable lens equipped with information correction for intermediate accessories to which the present invention is applied, and intermediate accessories used therein. The left side of the dashed line is the camera body X, the center is the intermediate accessory Y, The right side is the circuit on the interchangeable lens Z side. Terminal B ₀ on the camera body side is a power output terminal, and is connected to power input terminal P ₀ on the interchangeable lens side via terminal AC ₀ on the intermediate accessory. Terminal B ₁ on the camera body side is terminal AC ₁ on the intermediate accessory.
and input terminal P ₁ on the interchangeable lens side and inverter IN
Reset terminal RE of counters CO ₁ and CO ₂ via
It is connected to the. This input terminal P ₁ is “High” while receiving information from the interchangeable lens, and the counter CO ₁ ,
The CO ₂ reset is released. Output terminal _B2 on the camera body side is used to synchronize electrical operation between the interchangeable lens and the camera body.
A clock pulse from the camera body to the interchangeable lens is connected to the terminal CL of the counter CO ₁ via the terminal AC ₂ of the intermediate accessory and the input terminal P ₂ of the interchangeable lens. The counters CO ₁ and CO ₂ are 3-bit binary counters, and the counter CO ₁ counts the rising edge of the clock pulse from the input terminal P ₂ and outputs the clock pulse from the carry terminal from the rising edge of the 8th clock pulse to the rising edge of the next clock pulse. C.Y.
Set to “High”. Counter CO ₂ counts the fall of this carry terminal CY, and the count value of counter CO ₂ increases by 1 each time the first pulse of the 8th clock pulse rises. The 3-bit output E ₂ to _{E 0} of the counter CO ₂ is input to the decoder DE ₂ , and from this decoder DE ₂ ,
Depending on the contents of the counter CO ₂ , the output terminals S ₀ , S ₁ ,
S ₂ , S ₃ , and S ₄ are set to "High" in sequence, and a selection signal is output to data selector DS ₁ . Data selector DS ₁ selects input terminal AI ₅ when data select signal S ₀ from decoder DE ₂ is “High”.
~AI Output terminal for lens specific information AI set to ₀
Then, when the data select signal _S1 becomes " _High ", the lens specific information BI set in the input terminals _BI5 to _BI0 is outputted _to the output terminals _I5 to _I0 .
Similarly, when the data select signal advances to S ₂ , S ₃ , S ₄ , the input terminals CI ₅ to CI ₀ and DI ₅ to
Lens specific information CI set to DI ₀ , EI ₅ to EI ₀ ,
DI and EI are sequentially output to output terminals _I5 to _I0 .
Table 1 shows the relationship among the counter _CO2 , decoder _DE2 , and data selector _DS1 .

[Table] The lens specific information AI set to the input terminal of the data selector DS ₁ is set with the information identification code "000001" that identifies the quantity and content of the lens specific information output for this lens setting, and the amount of information is If there are many lenses, set the information identification code “000001”. The camera body reads this identification code and selects the subsequent information reading method.
The function code set for BI is: BI ₀ is “High” if the automatic aperture mechanism is built in, and BI ₁ is “High” if the linking mechanism for driving the focusing lens from the camera body is built in. and BI ₂ is set to “High” if the focusing lens is moved counterclockwise. CI has a set aperture value. In addition, in the case of a lens whose aperture value changes by changing the magnification, the aperture value at the maximum aperture value is set. DI is set to the focal length of the lens if it is a fixed focal length lens, or the shortest focal length if it is a variable focal length lens. EI is set with a conversion coefficient that corresponds to the amount of deviation of the imaging position of the subject to be focused detected by the camera body from the expected focal position to the amount by which the focusing lens is driven toward the expected focal position. has been done. Note that in the case of a variable focal length lens, the conversion coefficient on the long focal length side where the conversion coefficient is the smallest is set. The decoder DE ₂ outputs data select signals S ₀ to _{S 4} to the data selector DS ₁ , and at the same time outputs a part of the output signals S ₂ to _{S 4} to the data selector.
Also outputs to DS ₂ . When the data select signal _{S 2 from the decoder DE 2 is} “High”, the data selector DS 2 outputs the amount of information change CJ per unit movement corresponding to the focal length set to the input terminals CJ ₂ to _{CJ 0} . Similarly, when the data select signal advances to _{S 3 and} S ₄ , the information change amounts DJ and EJ set to the input terminals DJ ₄ to _{DJ 1 and} EJ ₅ to _{EJ 3} are output to the terminals J 5 to J 0 and at the same timing. are sequentially output to output terminals J ₅ to _{J 0} . Here, counter CO ₂ and decoder
Table 2 shows the relationship between DE ₂ and data selector DS ₂ .

[Table] The information change amount CJ set at the input terminal of the data selector DS ₂ is set as the amount of change in the open aperture per unit of movement corresponding to the focal length of the lens whose open aperture value changes due to zooming operations. There is.
DI is the amount of change in focal length per unit amount of movement,
The amount of change in the conversion coefficient per unit amount of movement is set for EJ. In addition, in the case of a fixed focus lens or a lens in which each information does not change due to zooming operation, each input terminal CJ ₂ ~ _{CJ 0} , DJ ₄ ~ DJ ₁ , EJ ₅ ~
Set “0” to EJ ₃ . In addition, due to differences in the precision required to set the amount of change in each information and the possible values of the amount of change, the number of input terminals of data selector DS ₂ and the output of the input information to output terminals J ₅ to _{J 0} may vary. The signal output position is determined in correspondence with each amount of information change. Next, the lens specific information AI, BI, CI, DI, EI is input to the input terminal of the data selector DS _1.
The following describes how to set the information change amounts CJ, DJ, and EJ input to the input terminals of the data selector DS ₂ . The optical design determines the maximum aperture, the focal length, the amount of shift in the focal position, and the amount of movement of the focusing lens, and the lens barrel design determines the function of the lens.
The conversion coefficient is determined by the direction and amount of lead of the focusing lens and the gear ratio of the drive mechanism that drives the focusing lens toward a predetermined focal position. This information is collected at the time when this output device is installed in the lens barrel.
Alternatively, it can be set during the preparation stage. To set a bit of each information to "0", connect the corresponding input terminal to ground, and to set it to "1", connect the corresponding input terminal to the power supply line +VF. In the case of a variable magnification lens, an encoder ENC is provided that outputs a 4-bit signal corresponding to the relative amount of movement from the reference position to the set position by operating a focal length variable magnification operation member (not shown). There is.
The sliding member VC is interlocked with the focal length changing operation member,
The focal length is set at one of the following positions. Continuity trace COM is grounded,
The other conduction patterns EC ₃ to _{EC 0} are each connected to the power supply line +VF via a resistor. Therefore,
When the contact piece of the sliding member VC comes into contact with any of the conductive patterns EC ₃ to _{EC 0} , the conductive pattern COM and the one of the conductive patterns EC ₃ to _{EC 0} that the sliding member VC is in contact with slides. It is short-circuited by the moving member VC, and the signal output becomes “Low”. Also, the signal output will be "High" even though there is no contact. The output of the conduction pattern EC ₃ of the encoder ENC is connected to one input terminal of the AND gates AN _A and AN _B , and the other input terminal is connected to the output terminal of the decoder DE _2.
The outputs of AND gates AN _A and AN _B are connected to one input terminal _{of exclusive OR gate ER 2 and} the input terminal of multiplication circuit MLT via OR gate OR _{3 .}
connected to. The output of the conduction pattern EC ₂ is connected to the other input terminal of the exclusive OR gate ER ₂ via the inverter IN ₂ , and the output of the exclusive OR gate ER ₂ is connected to one input terminal of the exclusive OR gate ER ₁ and the input terminal K of the multiplier circuit MLT. Connected to ₂ . The output of the conduction pattern EC ₁ is connected to the other input terminal of the exclusive OR gate ER ₁ via the inverter IN ₁ , and the output of the exclusive OR gate ER ₁ is connected to one input terminal of the exclusive OR gate ER ₀ and the input terminal K of the multiplier circuit MLT. Connected to ₁ . Further, the output of the conduction pattern EC ₀ is connected to the other input terminal of the exclusive OR gate ER ₀ via the inverter IN ₀ , and the output of the exclusive OR gate ER ₀ is connected to the input terminal K ₀ of the multiplication circuit MLT.
Table 3 shows the relationship between the outputs EC ₃ to _{EC 0} of the encoder ENC, the output S ₄ of the decoder DE ₂ , and the output signals to the input terminals K ₃ to _{K 0} of the multiplier circuit MLT at the focal length setting position. Shown below.

[Table] The conduction pattern of encoder ENC is output EC ₃ ~
EC ₀ is set as a gray code. When output terminal S ₄ of decoder DE ₂ is “Low”, the relative movement amount to the set position when the focal length set position is the reference position is the multiplier circuit.
It is output to input terminals K ₃ to _{K 0} of MLT. In addition, when the output terminal S ₄ of the decoder DE ₂ is “High”, the relative movement amount to the set position when the focal length setting position is the reference position is the input terminal K ₃ to _{K 0} of the multiplier circuit MLT. is output to. The reason why the focal length reference position is switched when the output terminal S ₄ signal of the decoder DE ₂ is "High" will be explained with reference to FIG. 2. In FIG. 2, the horizontal axis shows the setting position of the encoder ENC, and the vertical axis corresponds to the lens specific information value. In this lens, there are three types of lens-specific information that change with the focal length changing operation: the open aperture value, the focal length, and the conversion coefficient shown in FIG. Of these, the open aperture value and focal length are determined by the encoder.
As the ENC setting position advances to ~, the lens specific information changes in the direction of increasing. However, the conversion coefficient changes in the opposite direction.
Therefore, for the maximum aperture value and focal length, specify the encoder ENC setting position where the information value is minimum as the reference position, and input the maximum aperture value at this reference position to the input terminals CI ₅ to _{CI 0} of the data selector DS ₁ . The focal length is set for each input terminal DI ₅ to _{DI 0} . Also,
For the conversion coefficient, specify the minimum encoder ENC setting position as the reference position, and apply the conversion coefficient at this reference position to the input terminals EI ₅ to _{EI 0} of the data selector DS ₁ .
It is set to . Then, the relative movement amount from the reference position to the set position input to the input terminals K ₃ to _{K 0} of the multiplier circuit MLT is switched as shown in Table 3 depending on the difference between the reference position and the set position. The multiplier circuit MLT uses the output terminals _J5 to _J0 of the data selector _DS2 as the multiplicand, which is the 6-bit unit information change amount, and inputs the relative movement amount from the reference position at the encoder ENC setting position to the input terminals _K3 to
The amount of change is obtained by multiplying the 4 bits of _K0 as a multiplier. J ₅ J ₄ J ₃ J ₂ J ₁ J ₀ ... Multiplicand (unit information change amount) × K ₃ K ₂ K ₁ K ₀ ... Multiplier (relative movement amount) Adder circuit ADD is output terminal I of data selector DS _{1 5} ~ I Input 6 bits of lens specific information at the reference position from ₀ , input the multiplication result of the amount of change output from the multiplier circuit MLT, add the amount of change to the lens specific information at the reference position, and add The results are output to output terminals _O7 to _O0 . By this addition, the open aperture value, focal length, and conversion coefficient at the focal length setting position are determined. Note that the information identification code and function code are information that does not change due to the focal length changing operation, so the amount of change output from the multiplier circuit MLT is all "0", and therefore the change in information content due to the addition circuit ADD is do not have. The multiplier circuit MLT and the adder circuit ADD were previously proposed by the applicant in Japanese Patent Application No. 79303/1982, so their explanation will be omitted here. Next, we will explain information correction according to the characteristics of the intermediate accessory Y interposed between the interchangeable lens Z and the camera body X, for the lens-specific information output to the output terminals _O5 to _O0 of the adder circuit ADD. . Input terminals P ₅ , P ₆ on the side of interchangeable lens Z detect information indicating the type of intermediate accessory set in terminals AC ₅ , AC ₆ , of intermediate accessory Y, and input terminals AD _{1 ,} AD ₀ is input. Data selector DS ₃ is decoder DE ₂
When the data selection signal S ₂ from the aperture is "Hihg", the correction amount corresponding to the characteristics of the intermediate accessory regarding the maximum aperture value is output from the output terminals A ₅ to _{A 0} ,
Similarly, when the data select signal advances to S ₃ and S ₄ , at the same timing, the correction amount regarding the focal length and the correction amount regarding the conversion coefficient are sequentially output to the output terminals A ₅ to _{A 0} . Intermediate accessory type input terminal here
AD ₁ , AD ₀ , decoder DE ₂ and data selector
Table 4 shows the relationship with DS ₃ .

[Table] Since the intermediate accessory Y in this example is a 2x rear converter, type information indicating a 2x rear converter is set, with accessory type information terminal AC ₅ connected to ground and terminal AC ₆ open. ing. This setting information is for the interchangeable lens side Z.
is detected at the input terminals P ₅ and P ₆ of the data selector DS 3, and "Low" is input to the input terminal AD ₁ of the data selector DS ₃ , and "High" is input to AD ₀ . and data selector
The output terminals A ₅ to _{A 0} of the DS ₃ output the 2x rear converter's open aperture correction amount "000010" at the timing when the data select signal S ₂ of the decoder DE ₂ becomes "High". Then, when the data select signal _S3 becomes "High", the focal length correction amount "001000" is output, and when the data selection signal _S4 becomes "High", the conversion coefficient correction amount "110000" is output. FIG. 3 shows the circuit configuration of the correction calculation circuit ADJ shown in FIG. 1. Input the 6-bit correction amount from the output terminals _A5 to _A0 of the data selector DS ₃ , input the 8-bit lens-specific information to the output terminals _O7 to _O0 of the adder circuit ADD, and set the correction amount to the lens-specific information. is added,
The addition results are output to output terminals R ₇ to _{R 0} . Through this correction calculation, the open aperture value, focal length, and conversion coefficient corresponding to the characteristics of the intermediate accessory Y are determined. Note that since the information identification code and function code do not change due to the characteristics of the intermediate accessory Y, the correction amounts output from the data selector DS ₃ are all "0", and therefore, the information content changes due to the correction calculation circuit ADJ. There isn't. In addition, when attaching _the interchangeable lens Z directly to the camera body _X , since _the camera body ₆ are both open, and "High" is input to both input terminals AD ₁ and AD ₀ of data selector DS ₃ . data selector
Since DS ₃ outputs all “0” to output terminals A ₅ to _{A 0} when both input terminals AD ₁ and AD ₀ are “High”,
There is no change in the interchangeable lens information content due to the correction calculation circuit ADJ. Furthermore, even when an intermediate accessory, which is a conventional technique and is equipped with a correction calculation circuit corresponding to the characteristics on the intermediate accessory side, is interposed between the interchangeable lens Z and the camera body X, the input terminal P ₅ of the interchangeable lens Z , _P6 is not provided in the prior art product, so there is no change in the interchangeable lens information content by the correction calculation circuit ADJ. Therefore, even if conventional technology products or special intermediate accessories that cannot be fully corrected on the interchangeable lens Z side are constructed using the prior art technology, compatibility is ensured on the interchangeable lens side. Returning to FIG. 1 again, explanation will be given. The 3-bit output C ₂ to _{C 0} of the counter CO ₁ is input to the decoder DE ₁ , and from this decoder DE ₁ ,
The signals shown in Table 5 are output depending on the contents of counter _CO1 .

[Table] The output terminals D ₀ to D ₇ of the decoder DE ₁ are connected to one input terminal of the AND gates AN ₀ to _{AN 7} , and the other is connected to the output terminals R ₀ to _{R 7} of the correction calculation circuit ADJ. The output of gates AN ₀ to AN ₇ is OR gate OR, terminal P ₃ , intermediate accessory terminal AC ₃ ,
Outputs a signal to the camera body side X via terminal _B3 . When the counter advances by one at the rising edge of the clock pulse, the output terminal D ₀ of the decoder DE ₁ becomes “High”, the gate of the AND gate AN ₀ is opened, and the signal at the output terminal R ₀ of the correction calculation circuit is converted to an OR gate.
Output via . In this way, each time the clock pulse rises, the output terminal _R0 of the correction calculation circuit
_-R7 signals are sequentially output one bit at a time from the least significant bit to the camera body side X via AND gates _AN0 to _AN7 , OR gate OR, and terminals _P3 , _AC3 , and _B3 . The intermediate accessory used in the interchangeable lens equipped with intermediate accessory information correction will now be explained. Intermediate accessory Y has a terminal as a type information setting section to indicate the type of accessory.
AC ₅ and AC ₆ are provided on the mount surface on the interchangeable lens side, and each terminal is connected to ground or left open, and accessory type information is uniquely set. However, since the setting where both terminals are open is determined by the data selector DS ₃ in the same way as when the interchangeable lens Z is attached directly to the camera body X, there is no change in the information content provided by the correction calculation circuit ADJ.
In addition, in this embodiment, a terminal is used as a type information setting section to indicate the type of intermediate accessory.
AC ₅ and AC ₆ are connected to the input terminals P ₅ and P ₆ on the interchangeable lens side by two electrical contacts each, but the number of electrical contacts can be increased or decreased as appropriate depending on the type of intermediate accessory. . In addition, the intermediate accessory Y includes terminals and conductive wires that directly transmit signals output from the information output device of the interchangeable lens to the camera body X, as well as power supply, ground, and control signals supplied from the camera body X. A terminal and a conductive wire are provided for transmitting signals to the lens Z, and signals are transmitted in the same way as when the interchangeable lens Z is directly attached to the camera body X. In the above, an example of a fixed magnification rear converter such as a 1.4x rear converter or a 2x rear converter was explained as an intermediate accessory.Next, the case of a variable magnification rear converter will be explained with reference to the block diagram of FIG. 4. Power, ground, control signals, and information input output from the control circuit 2 including the CPU of the camera body 1 are connected to terminals T ₁ to _{T 5} provided on the mount surface.
Terminals T ₆ to _{T 10} provided on the camera body side mount surface of the variable magnification rear converter 3, terminals T ₁₁ to _{T 15} provided on the interchangeable lens side mount surface connected by conductive wires, and the interchangeable lens 6. It is connected to the interchangeable lens information output circuit 7 via terminals T ₁₉ to _{T 23} provided on the mounting surface of the lens. The intermediate accessory type information is then connected to the interchangeable lens information output circuit 7 via terminals T ₁₆ to T ₁₈ and T ₂₄ to _{T 26} provided on the mount surface on the interchangeable lens side, and the interchangeable lens which has been corrected according to the accessory characteristics Information is transmitted to the camera body. Up to this point, the explanation is the same as that of a fixed magnification converter, but in the case of a variable magnification rear converter, the optical characteristics change from, for example, 1.4x to 3x by changing the magnification.
Interchangeable lens information corresponding to the amount of change in optical characteristics must be transmitted to the camera body. Therefore, in order to cope with the amount of change in optical characteristics due to the variable magnification operation, a 3-bit encoder 4, for example, is provided in the variable magnification rear converter 3, and the position of contact between the sliding member 5 and the encoder pattern, which are linked to the variable magnification operation, can be adjusted accordingly. The characteristic information of the setting magnification is from terminal T ₁₆ ~
It may be configured such that the interchangeable lens information is input to the interchangeable lens information output circuit 7 via _T18 and _T24 to _T26 , and the interchangeable lens information subjected to a predetermined correction calculation is transmitted to the camera body. Next, the case where the optical system is removable from the lens barrel in a double converter which is an intermediate accessory will be explained with reference to the block diagram of FIG. In FIG. 5, parts that perform the same functions as those in FIG. 4 are given the same numbers and their explanations will be omitted. In the converter lens barrel, the optical system inside the lens barrel is removably installed, and when the optical system is attached, it exhibits the characteristics as a 2x rear converter, and when the optical system is removed, the characteristics change as an intermediate ring, so this change in optical characteristics The corresponding interchangeable lens information must be transmitted to the camera body. Therefore, a switch SS is installed inside the lens barrel to detect whether the optical system is attached or detached, and when the optical system is attached to the lens barrel, the detection switch
SS is closed, and information indicating the double converter is input to the interchangeable lens information output circuit 7 as accessory characteristic information through terminals T ₁₆ to _{T 17} and T ₂₄ to T ₂₆ . Also, when the optical system is detached from the lens barrel, the detection switch is activated.
It may be configured such that the SS is opened, information indicating the intermediate ring is input to the interchangeable lens information output circuit 7, and interchangeable lens information subjected to predetermined correction calculations is transmitted to the camera body. In the above-described embodiments, the circuit section of the present invention was composed of individual circuit elements, but the entire circuit section could be composed of a microprocessor such as a one-chip microcomputer to sequentially control the information output device of the present invention. It's okay. (Effects of the Invention) The present invention detects the type of intermediate accessory inserted between the interchangeable lens and the camera body, responds to the characteristics of the detected type of intermediate accessory, and responds to the unique information of the interchangeable lens. Since the interchangeable lens side is equipped with an information output device that performs correction calculations and outputs the calculated information to the camera body,
This allows the camera body's exposure control, automatic focus adjustment, and display to function normally. The intermediate accessory used in the interchangeable lens with information correction according to the present invention has a configuration in which the accessory type information detected by the information output circuit on the interchangeable lens side is set, and the signal output from the interchangeable lens is directly transmitted to the camera body. Therefore, an IC equipped with a correction calculation circuit, an information output circuit, etc. on the intermediate accessory side becomes unnecessary, and the configuration becomes simple. Further, even if an intermediate accessory, which is a conventional intermediate accessory equipped with a correction calculation circuit corresponding to the characteristics, is inserted between the interchangeable lens equipped with the information output device of the present invention and the camera body, information will not be transmitted normally. output is possible, and compatibility with conventional technology products is also ensured. Furthermore, according to the present invention, since a correction calculation circuit corresponding to the characteristics of the intermediate accessory is incorporated into the information output device on the interchangeable lens side, the unit price of the interchangeable lens side IC may increase. However, compared to the conventional technology in which a correction calculation circuit and an information output circuit are provided on the intermediate accessory side, the present invention is more effective in reducing costs.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an information output device for an interchangeable lens equipped with intermediate accessory information correction to which the present invention is applied, and an intermediate accessory used therein, and Fig. 2 is a relational diagram showing the relationship between lens-specific information and encoder setting positions. 3 is a circuit configuration diagram of a correction calculation circuit, and FIGS. 4 and 5 are block diagrams showing a rear converter with variable magnification and a rear converter with a detachable optical system. CO ₁ , CO ₂ ... Counter, DE ₁ , DE ₂ ... Decoder, AI, BI, CI, DI, EI ... Lens specific information, DS ₁ , DS ₂ , DS ₃ ... Data selector,
CJ, DJ, EJ...Amount of information change, ADD...Addition circuit, MLT...Multiplication circuit, ADJ...Correction calculation circuit, ENC...Encoder, SS...Switch, 1
... Camera body, 2 ... Control circuit, 3 ... Rear converter, 4 ... Encoder, 5 ... Sliding member, 6 ... Interchangeable lens, 7 ... Interchangeable lens information output circuit.

Claims (1)

[Claims] 1. In a camera system in which unique information based on an electrical signal of an interchangeable lens is electrically transmitted from the interchangeable lens to the camera body, the information is transmitted from an intermediate accessory interposed between the interchangeable lens and the camera body. a detection means for detecting the type of the interchangeable lens based on an electric signal; a calculation means for performing a correction operation on the unique information generated by the electric signal of the exchange lens in accordance with the characteristics of the intermediate accessory of the detected type; 1. An information output device for an interchangeable lens equipped with information correction for an intermediate accessory, comprising: output means for outputting information based on an electric signal calculated by the means to a camera body side. 2. In a camera system in which unique information based on an electric signal of an interchangeable lens is electrically transmitted from the interchangeable lens to the camera body, an intermediate accessory interposed between the interchangeable lens and the camera body, which includes an interchangeable lens side circuit. and a type information setting means for outputting information in the form of an electric signal indicating the type of the intermediate accessory, and a signal transmission means for directly transmitting the signal output from the information output device of the interchangeable lens to the camera body. intermediate accessories.