JP5443045B2 - Camera system, interchangeable lens and intermediate accessories constituting camera system - Google Patents

Description

The present invention provides a camera system and a camera system capable of outputting lens specific information corresponding to characteristics of an intermediate accessory such as a rear converter, an intermediate ring, and a bellows interposed between an interchangeable lens and a camera body to the camera body. The present invention relates to an interchangeable lens and intermediate accessory technology.

Conventionally, various unique information of an interchangeable lens, for example, an open aperture value, a focal length, a conversion coefficient for associating a defocus amount for automatic focus adjustment with a driving amount of a focusing lens, and the like from the interchangeable lens to the camera body Electrically transmitted and used for automatic exposure control, automatic focus adjustment control and display control by the camera body.

On the other hand, there is a camera system that is used by interposing intermediate accessories such as a rear converter, an intermediate ring, and a bellows between the interchangeable lens and the camera body. In such a camera system, when an intermediate accessory is interposed between the interchangeable lens and the camera body, the aperture value, the focal length, the feed amount conversion coefficient, etc. are combined values based on the characteristics of the interchangeable lens and the intermediate accessory. There must be. Therefore, when an intermediate accessory is interposed between the interchangeable lens and the camera body, automatic exposure control, automatic focus adjustment control, etc. by the camera body can be performed only by transmitting the lens-specific information of the interchangeable lens to the camera body as it is. There was a problem that it did not function properly and display on the camera itself was not accurate.

Therefore, as an invention for solving this problem, an apparatus described in Japanese Patent Application Laid-Open No. 59-188622 (hereinafter referred to as Patent Document 1) has been proposed. The apparatus includes an arithmetic circuit that corrects the lens-specific information received from the interchangeable lens according to the characteristics of the intermediate accessory in the intermediate accessory, and an output circuit that outputs the calculated lens-specific information to the camera body. Intermediate accessory. In the invention described in Patent Document 1, the intermediate accessory performs a correction operation according to the characteristic on the lens specific information transmitted from the interchangeable lens to the camera body, so that the intermediate accessory is located between the interchangeable lens and the camera body. The intervening camera system also ensures the normal functioning of the camera body.

Japanese Examined Patent Publication No. 4-1331 (hereinafter referred to as Patent Document 2) describes an intermediate accessory provided with an electrical contact for transmitting the presence and type of the intermediate accessory to the interchangeable lens. The interchangeable lens attached to this intermediate accessory detects the presence and type of the intermediate accessory from its electrical contacts, and the lens-specific information of the interchangeable lens or the characteristics of the detected type of the intermediate accessory according to the presence and type information Lens-specific information that has been corrected according to

Japanese Patent Laid-Open No. 2002-72328 (hereinafter referred to as Patent Document 3) outputs from an interchangeable lens without newly providing an electrical contact in an intermediate accessory or the like as in the invention described in Patent Document 2. The intermediate accessory performs a predetermined correction operation on the predetermined lens specific information and outputs it to the camera body.The camera body returns the received lens specific information to the interchangeable lens as it is, and the interchangeable lens receives the data sent from the camera main body. A camera system has been proposed in which the presence and type of an intermediate accessory can be determined by receiving and comparing this data with lens-specific information of an interchangeable lens.

Further, in Japanese Patent Application No. 2008-217340 filed earlier by the present applicant, it was further described in Patent Document 3 without newly providing an electrical contact in an intermediate accessory or the like as in the invention described in Patent Document 2. Without providing an IC with a correction arithmetic circuit in the intermediate accessory as in the invention, after the camera body transmits a signal to start data communication to the interchangeable lens and the intermediate accessory, the intermediate accessory moves from the camera body to the interchangeable lens. An electrical signal indicating the presence and type of the intermediate accessory is added to the predetermined signal to be transmitted, and the interchangeable lens detects the presence and type of the intermediate accessory by detecting this predetermined signal, and the recognized intermediate accessory A camera system that transmits lens-specific information that has been corrected according to its presence and type to the camera body, and replacement that constitutes the camera system It has proposed a lens and intermediate accessory.

JP 59-188622 A

Japanese Patent Publication No.4-1331

JP 2002-72328 A

In the invention described in Patent Document 1 described above, it is necessary to incorporate an IC including a correction operation circuit according to the characteristics of each type of intermediate accessory, and the cost of the intermediate accessory is inevitable. In general, the intermediate accessory has a character as an auxiliary tool in the camera system, and is expected to be cheaper by the consumer, and the high cost is a big problem for the intermediate accessory.

In addition, the correction arithmetic circuit incorporated in the intermediate accessory described in Patent Document 1 is set in advance so as to perform a theoretical correction calculation according to the characteristics of each type of the intermediate accessory. The optimal correction calculation is not performed in accordance with the characteristics of the interchangeable lens having the.

In order to perform automatic exposure control, automatic focus adjustment control, etc. with high precision and display more accurately, the lens specific information is not a logical correction calculation value according to the characteristics of the type of intermediate accessory as described above. It is necessary to be an accurate composite value of an interchangeable lens having various types of optical systems and an intermediate accessory. However, in the correction calculation circuit for the intermediate accessory described in Patent Document 1, there is a problem that high-precision correction calculation according to the characteristics of the interchangeable lens having various types of optical systems attached to the intermediate accessory cannot be performed. there were.

The interchangeable lens and the intermediate accessory described in the cited document 2 that solves the above-described problem of the intermediate accessory described in Patent Document 1 are provided with electrical contacts that transmit the presence and type of the intermediate accessory to the interchangeable lens. The presence and type of the intermediate accessory is detected from the electrical contact, and the lens-specific information of the interchangeable lens is determined according to the presence and type of information, or the lens-specific information is corrected according to the detected characteristics of the intermediate accessory. Are an interchangeable lens and an intermediate accessory.

In the interchangeable lens and the intermediate accessory described in Patent Document 2, it is only necessary to provide an electrical contact that transmits the presence / absence and type of the intermediate accessory to the interchangeable lens. Intermediate accessories can be provided. In addition, since the interchangeable lens can detect the presence and type of the intermediate accessory from the electrical contacts, the lens-specific information of the interchangeable lens or the characteristics of the detected type of the intermediate accessory depending on the presence and type of information Since the unique information that has been subjected to the correction calculation according to can be output to the camera body, the accuracy of the camera system in which the intermediate accessory is interposed between the interchangeable lens and the camera body can be improved.

However, depending on the camera system, there is a contact terminal structure provided in the interchangeable lens and the intermediate accessory described in Patent Document 2 with no room for providing an electrical contact for transmitting the presence / absence and type of the intermediate accessory to the interchangeable lens. There is something to have.

In order to improve the accuracy of a camera system that cannot afford to add an electrical contact to an interchangeable lens, a camera body, and an intermediate accessory interposed therebetween, the camera system described in Patent Document 3 and an interchangeable lens that constitutes the camera system, In the camera body and the intermediate accessory, the intermediate accessory performs a predetermined correction operation on the predetermined lens specific information output from the interchangeable lens and outputs it to the camera body. The camera main body receives the received lens specific information in the interchangeable lens. An invention has been proposed in which the interchangeable lens receives the data sent from the camera body and compares the data with the lens-specific information of the interchangeable lens so that the presence and type of the intermediate accessory can be determined. Yes. In this configuration, the addition of electrical contacts described in Patent Document 2 is unnecessary.

Since there is no additional electrical contact in this system, the cost of contact terminals can be reduced, but an IC with a correction arithmetic circuit is required in the intermediate accessory, and it is much more expensive to mount the IC. Therefore, the overall cost of the camera system is unavoidable.

Furthermore, in order to achieve the camera system described in Patent Document 3, an IC for correction calculation is mounted on the intermediate accessory, and the camera body is improved by returning the lens-specific information of the interchangeable lens to the interchangeable lens. Since the lens must be provided with a means for determining the presence or absence of an intermediate accessory, the configuration of the entire camera system is inevitably complicated.

In Japanese Patent Application No. 2008-217340 filed earlier by the present applicant, in order to provide an intermediate accessory that has a simple configuration, does not require the addition of an electrical contact or an IC having a correction arithmetic circuit, and suppresses an increase in cost. An electrical signal indicating the presence and type of the intermediate accessory for a predetermined signal transmitted from the camera body to the interchangeable lens after the camera body transmits a signal to start data communication to the interchangeable lens and the intermediate accessory. And the interchangeable lens detects the presence and type of the intermediate accessory by detecting the predetermined signal, and the lens-specific information corrected according to the presence and type of the recognized intermediate accessory is sent to the camera body. We proposed a camera system to transmit, an interchangeable lens and intermediate accessories that make up the camera system.

However, depending on the specifications of the camera system, there may be a relatively short time interval from the start of data communication between the camera body and the interchangeable lens until the actual data communication is performed. After the reception, there is a signal that has no time for adding an electrical signal indicating the presence and type of the intermediate accessory to the predetermined signal transmitted from the camera body to the interchangeable lens by the intermediate accessory.

The present invention is not compatible with the camera system described in Japanese Patent Application No. 2008-217340, even if the camera system has a relatively short time interval between the start of data communication and the actual data communication. In order to solve this problem, the structure is simple, no additional electrical contacts or ICs with correction operation circuits are required, and the presence and type of intermediate accessories can be recognized without increasing costs. Lens-specific information that has undergone correction calculations according to the characteristics of the intermediate accessories recognized in step 1, can be output to the camera body, automatic exposure control, automatic focus adjustment control, etc. can be functioned with high precision in the camera body, and display is also possible It is an object to provide a camera system that can be performed more accurately, an interchangeable lens that constitutes the camera system, and an intermediate accessory.

The first camera system of the present invention includes:
An interchangeable lens is detachable from the camera body, and an intermediate accessory is interposed between the interchangeable lens and the camera body, and between the interchangeable lens and the intermediate accessory and between the intermediate accessory and the camera. Each of the interchangeable lenses is electrically connected to the main body via a plurality of terminals provided in the same number , and the interchangeable lens is connected to the main body using a plurality of predetermined digital electric signals passing through the terminals. In a camera system that transmits lens-specific information to the camera body,
Said camera body, the interchangeable lens and the power supply to the intermediate accessory, intermediate accessory, between the power supply before starting communication, the predetermined digital electrical signal to be transmitted from said camera body to said interchangeable lens Instead, a predetermined analog electrical signal indicating the presence and type of the intermediate accessory is output to the interchangeable lens only through the plurality of terminals, and is transmitted from the camera body to the interchangeable lens after communication is started. connect the predetermined digital electric signals,
The interchangeable lens until before communication starts from the power supply, and determines the presence or absence and the type of the intermediate accessory by detecting the predetermined analog electric signals, after the start of communication in the presence or absence and type of intermediate accessory In this camera system, lens-specific information on which a corresponding correction operation has been performed is transmitted to the camera body.

In the second camera system of the present invention, in the first camera system, the lens specific information subjected to the correction calculation is a command for the lens CPU of the interchangeable lens to request lens specific information from the camera CPU of the camera body. each time it receives a signal, reads out the lens specific information stored in the storage area of the lens CPU, the first, which is a lens specific information which has been subjected to correction operation in accordance with the presence or absence and type of intermediate accessory It is a camera system.

According to a third camera system of the present invention, in the first camera system, the correction information according to the presence / absence and type of the intermediate accessory is preliminarily applied to the lens specific information subjected to the correction calculation. The first camera system is characterized in that the first camera system is read from the storage area.

The first interchangeable lens of the present invention is
It is detachable with respect to the camera body or the intermediate accessory, and an intermediate accessory can be interposed between the interchangeable lens and the camera body, between the interchangeable lens and the intermediate accessory, and between the intermediate accessory and the camera A plurality of predetermined terminals passing through the plurality of terminals are electrically connected to each other through a plurality of terminals provided between the main body or between the interchangeable lens and the camera body . In the interchangeable lens constituting the camera system in which the interchangeable lens transmits lens specific information to the camera body using a digital electrical signal,
When the intermediate accessory is interposed between the interchangeable lens and the camera body,
The camera body supplies power to the interchangeable lens and the intermediate accessory,
Between the power supply and before the start of communication , the interchangeable lens receives the predetermined analog electrical signal indicating the presence and type of an intermediate accessory instead of the predetermined digital electrical signal with the camera body only for the plurality of terminals. recognizing the presence or absence and the type of the intermediate accessory by detecting through said predetermined digital electrical after the start of communication of the lens-specific information with the correction operation depending on the presence or absence and the type of the intermediate accessory to said camera body Send by signal ,
When the intermediate accessory is not interposed between the interchangeable lens and the camera body,
The camera body supplies power to the interchangeable lens,
The interchangeable lens recognizes that the intermediate accessory is not attached by detecting the predetermined signal transmitted from the camera body to the interchangeable lens between the time when the power is supplied and before the start of communication. intact lens specific information is not an interchangeable lens and transmits to the camera body.

In the second interchangeable lens of the present invention, in the first interchangeable lens, the lens unique information subjected to the correction calculation is a command for the lens CPU of the interchangeable lens to request lens unique information from the camera CPU of the camera body. Each time a signal is received, the lens unique information stored in the storage area of the lens CPU is read, and the lens unique information is corrected according to the presence and type of the intermediate accessory. It is an interchangeable lens.

In the third interchangeable lens of the present invention, in the first interchangeable lens, the correction information according to the presence / absence and type of the intermediate accessory is preliminarily performed on the lens specific information on which the correction calculation has been performed. This is a first interchangeable lens that is read from the storage area.

The first intermediate accessory of the present invention can be attached to and detached from a camera body or an interchangeable lens, and an intermediate accessory can be interposed between the interchangeable lens and the camera body. The interchangeable lens and the intermediate accessory And between the intermediate accessory and the camera body, or between the interchangeable lens and the camera body, respectively, are electrically connected via a plurality of terminals provided in the same number , In an intermediate accessory constituting a camera system in which the interchangeable lens transmits lens specific information to the camera body using a plurality of predetermined digital electrical signals passing through a plurality of terminals,
Intermediate accessory, between the power supply before starting communication, cutting the predetermined digital electrical signal to be transmitted from said camera body to said interchangeable lens, predetermined analog indicating whether the type of the intermediate accessory instead an electrical signal through only the plurality of terminals and output to the interchangeable lens, to recognize the presence or absence and the type of the intermediate accessory to the interchangeable lens, after the communication start of the predetermined transmitted from said camera body to said interchangeable lens connect the digital electric signal, the lens specific information with the correction operation depending on the presence or absence and the type of the intermediate accessory to the interchangeable lens is an intermediate accessory, characterized in that cause transmitted to the camera body.

According to the present invention,
In the camera system in which an intermediate accessory can be interposed between the interchangeable lens and the camera body,
Without the need for new electrical contacts, reduce the cost of intermediate accessories,
The intermediate accessory transmits an analog electrical signal indicating the presence and type of the intermediate accessory to the interchangeable lens even if the time from the start of data communication between the interchangeable lens and the camera body to the start of data communication is short Can
An interchangeable lens can provide a camera system capable of transmitting lens-specific information subjected to correction calculation with high accuracy according to the characteristics of the intermediate accessory and the interchangeable lens to the camera body, an interchangeable lens constituting the camera system, and an intermediate accessory. it can.

It is a block diagram which shows the electrical constitution at the time of attaching an interchangeable lens directly to a camera main body in the Example of this invention. FIG. 4 is a block diagram showing an electrical configuration when an intermediate accessory is interposed between the interchangeable lens and the camera body in the embodiment of the present invention. 4 shows a ROM address of lens specific information set in a storage area (ROM) in the lens CPU in the embodiment of the present invention. In the embodiment of the present invention, the correction value corresponding to the characteristic of the intermediate accessory set in the storage area (ROM) in the lens CPU and its ROM address are shown. In the embodiment of the present invention, it is an example of a signal when the interchangeable lens is directly attached to the camera body and 8-bit serial synchronous three-wire bidirectional communication is performed between the interchangeable lens and the camera body. In the embodiment of the present invention, a signal example in the case of performing 8-bit serial synchronous three-wire bidirectional communication with a 1.4 × rear converter as an example of an intermediate accessory interposed between the interchangeable lens and the camera body. . It is a signal example of the analog electric signal which shows the presence and kind of various intermediate accessories which intermediate accessory CPU output in the Example of this invention. In the embodiment of the present invention, the lens unique information set in the storage area (ROM) in the lens CPU and the ROM address of the correction calculation solution of the lens unique information corresponding to the characteristics of a plurality of types of intermediate accessories are shown. It is a flowchart which shows operation | movement of lens CPU in the Example of this invention. It is a flowchart which shows operation | movement of lens CPU which performs the correction | amendment calculation subroutine according to the characteristic of the intermediate | middle accessory in the Example of this invention. In the embodiment of the present invention, the lens CPU stores in advance a plurality of types of lens specific information that has been subjected to a correction calculation according to the characteristics of the intermediate accessory, and the lens specific information that has been subjected to the correction calculation by designating a ROM address. It is a flowchart which shows operation | movement of lens CPU which performs the correction | amendment calculation subroutine to output. 4 is a flowchart showing an operation of the 1.4x rear converter outputting an analog electrical signal indicating the presence and type of an intermediate accessory from the intermediate accessory CPU in the embodiment of the present invention. 6 is a flowchart showing an operation of the double rear converter outputting an analog electrical signal indicating the presence / absence and type of an intermediate accessory from the intermediate accessory CPU in the embodiment of the present invention. FIG. 4 is a block diagram showing an electrical configuration when an intermediate accessory is interposed between the interchangeable lens and the camera body in the embodiment of the present invention, and is a block diagram in which the intermediate accessory CPU is replaced with a general-purpose discrete electrical component.

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals denote the same parts in the drawings.

FIG. 1 is a block diagram showing an electrical configuration when an interchangeable lens is directly attached to a camera body in an embodiment of the present invention. FIG. 2 is a block diagram showing an electrical configuration when an intermediate accessory is interposed between the interchangeable lens and the camera body in the embodiment of the present invention. FIG. 3 shows the ROM address of the lens specific information set in the storage area (ROM) in the lens CPU in the embodiment of the present invention. FIG. 4 shows a correction value corresponding to the characteristic of the intermediate accessory set in the storage area (ROM) in the lens CPU and its ROM address in the embodiment of the present invention. FIG. 5 is a signal example when the interchangeable lens is directly attached to the camera body in the embodiment of the present invention and 8-bit serial synchronous three-wire bidirectional communication is performed between the interchangeable lens and the camera body. FIG. 6 shows a case in which 8-bit serial synchronous three-wire bidirectional communication is performed by interposing a 1.4 × rear converter as an example of an intermediate accessory between the interchangeable lens and the camera body in the embodiment of the present invention. It is an example of a signal. FIG. 7 is a signal example of an analog electric signal indicating the presence and type of various intermediate accessories output by the intermediate accessory CPU in the embodiment of the present invention.
FIG. 8 shows the ROM address of the lens specific information set in the storage area (ROM) in the lens CPU and the correction calculation solution of the lens specific information corresponding to the characteristics of a plurality of types of intermediate accessories in the embodiment of the present invention. It is. FIG. 9 is a flowchart showing the operation of the lens CPU in the embodiment of the present invention. FIG. 10 is a flowchart showing the operation of the lens CPU that performs a correction calculation subroutine according to the characteristics of the intermediate accessory in the embodiment of the present invention. FIG. 11 shows a lens in which a lens CPU stores a plurality of types of lens-specific information that has been corrected according to the characteristics of the intermediate accessory in advance in the embodiment of the present invention, and has been corrected by specifying a ROM address. It is a flowchart which shows operation | movement of lens CPU which performs the correction | amendment calculation subroutine which outputs specific information. FIG. 12 is a flowchart showing an operation in which the 1.4 × rear converter outputs an analog electric signal indicating the presence / absence and type of the intermediate accessory to the command signal from the intermediate accessory CPU in the embodiment of the present invention. FIG. 13 is a flowchart illustrating an operation in which the double rear converter outputs an analog electric signal indicating the presence / absence and type of the intermediate accessory from the intermediate accessory CPU to the command signal in the embodiment of the present invention. FIG. 14 is a block diagram showing an electrical configuration when an intermediate accessory is interposed between the interchangeable lens and the camera body in the embodiment of the present invention, and a block diagram in which the intermediate accessory CPU is replaced with a general-purpose discrete electrical component. It is.

Next, the configuration of the camera system of the present invention will be described.

First, an outline of data communication between the camera body B and the interchangeable lens L will be described with reference to FIG.

In FIG. 1, the left side of the alternate long and short dash line shows the circuit of the camera body B, and the right side shows the circuit of the interchangeable lens L. Command signal terminal B. of camera body B The command signal terminal L. of the interchangeable lens L from the CMD. The command signal CMD to the CMD is the communication clock signal B. of the camera body B. CLK to the communication clock signal terminal L. of the interchangeable lens L. It is transmitted in synchronization with the communication clock signal CLK to CLK. The interchangeable lens L transmits predetermined lens specific information according to the request of the received command signal CMD to the answer signal terminal L.P. Answer signal terminal B. of camera body B from ANS. An answer signal ANS is transmitted to the ANS in synchronization with the communication clock signal CLK.

For example, as shown in FIG. 3, the interchangeable lens L stores an information identification code (AI) in the ROM address 100h (h indicates hexadecimal notation) as lens specific information, and the function code (BI) is 101h. The maximum aperture value (CI) is stored in 102h, the focal length (DI) is stored in 103h, and the conversion coefficient (EI) is stored in 104h. For the camera body B, as a command signal CMD for requesting a response of unique information stored in the interchangeable lens L, for example, an information identification code request (AC), a function code request (BC), an open aperture value request (CC), a focus A distance request (DC) and a conversion coefficient request (EC) are prepared, and each command signal CMD is transmitted to the interchangeable lens L in accordance with the convenience of the automatic exposure control and automatic focus adjustment control of the camera body B, and each command Corresponding lens specific information is read from a predetermined ROM address in response to the signal CMD, and responded to the camera body B.

Next, terminals provided on the camera CPU and the lens CPU will be described with reference to FIG.

When the interchangeable lens L is mounted on the camera body B by mounting, each terminal of the camera CPU of the camera body B and each terminal of the lens CPU of the interchangeable lens L are connected to each other as shown in FIG.

The camera body B is provided with a camera battery BT. Power input terminal B. Power is supplied from VDD to the camera CPU. A power control terminal B of the camera CPU. VCNT is connected to the gate terminal of the MOSFET in the camera. The camera battery BT is connected to the power input terminal L. of the lens CPU via the in-camera MOSFET and the mount contact terminal. Connected to VDD. When a power switch (not shown) connected to the camera CPU is turned on or a release switch (not shown) is turned on, the camera CPU first turns on the power control terminal B. VCNT is set to “Hi”. Then, the MOSFET in the camera conducts current, and from the camera battery BT via the mount contact terminal, the power input terminal L.L. Power is supplied to VDD. The ground terminal B. having a common ground is connected to the camera CPU and the lens CPU. GND and L.G. A GND is provided.

Communication enable signal terminal B. of camera CPU ENBL to lens CPU communication enable signal terminal L. A communication enable signal ENBL, which is a signal for the camera CPU to start data communication, is transmitted to ENBL. The communication enable signal ENBL is “Hi” before starting data communication between the camera CPU and the lens CPU, and is “Low” during data communication.

Communication clock signal terminal B. of camera CPU CLK to the communication clock signal terminal L. of the lens CPU. A communication clock signal CLK that is a synchronization signal for data communication between the camera CPU and the lens CPU is transmitted to CLK. The clock signal CLK is “Hi” before the start of data communication between the camera CPU and the lens CPU, and continuously generates one synchronization signal that repeats “Low” and “Hi” 8 times alternately during data communication. To do.

Command signal terminal B. of camera CPU The command signal terminal L. of the lens CPU from the CMD. A command signal CMD for requesting predetermined lens specific information is transmitted from the camera CPU to the lens CPU. The command signal CMD constitutes one command signal CMD with a total of 8 bits of “Low” indicating 0 and “Hi” indicating 1.

Answer signal terminal L. of the lens CPU. Answer signal terminal B. of camera CPU from ANS. An answer signal ANS for transmitting lens specific information in response to the command signal CMD from the camera CPU is transmitted to the ANS. The answer signal ANS constitutes one answer signal ANS with a total of 8 bits of “Low” indicating 0 and “Hi” indicating 1.

B. described above. CLK-L. Communication clock signals CLK, B. CMD-L. Command signals CMD, B. ANS-L. An answer signal ANS communicating between ANS and a bidirectional communication system using these three signals are generally called 8-bit serial synchronous three-wire bidirectional communication.

Next, as shown in FIG. 1, in the embodiment of the present invention, when the interchangeable lens L is directly attached to the camera body B, a signal example of 8-bit serial synchronous three-wire bidirectional communication between the camera CPU and the lens CPU is shown. This will be described with reference to FIG. The signal example shown in FIG. 5 is described based on each terminal of the camera CPU, but the same signal example naturally appears between the terminals connected by the camera CPU, the lens CPU, and an intermediate accessory CPU described later.

In FIG. 5, when the switch of the camera body B is turned on or the release button is turned on, the camera CPU is connected to the power control terminal B.P. By setting VCNT to “Hi”, the MOSFET in the camera passes current, and the camera battery BT supplies power to the lens CPU. Then, after a predetermined time has elapsed, the communication enable terminal B. “Low” is output from ENBL, and a signal to start data communication is transmitted to the lens CPU. Next, when the camera CPU sets the command signal CMD for requesting lens specific information to the lens CPU in the communication output register of the camera CPU, the communication clock signal CLK for 8 bits is automatically set to the communication clock signal terminal B.B. The command signal CMD output from the CLK is synchronized with the communication clock signal CLK and the command signal terminal B.B of the camera CPU. The command signal terminal L. of the lens CPU from the CMD. 8 bits are transmitted to CMD.

When the lens CPU receives the command signal CMD transmitted from the camera CPU in synchronization with the communication clock signal CLK, the lens CPU determines what lens specific information is requested by the camera CPU corresponding to the command signal CMD. The requested lens specific information stored in advance in the ROM in the lens CPU is read out and set in the communication output register of the lens CPU. Then, after a predetermined time has elapsed, in synchronization with the 8-bit communication clock signal CLK output from the camera CPU, the answer signal ANS is sent as the requested lens specific information to the answer signal terminal B. of the camera CPU. 8 bits are transmitted to ANS.

In the above description, a signal example of 8-bit serial synchronous three-wire bidirectional communication in which one lens specific information is an answer signal ANS for one command signal CMD is shown. The above lens-specific information can be used as the answer signal ANS, and may be selected according to the design convenience.

In the above description, the configuration when the interchangeable lens L is directly attached to the camera body B and the signal example of data communication have been described. Next, a configuration in which an intermediate accessory is interposed between the camera body B and the interchangeable lens L, a signal example of data communication, and a mechanism for detecting the presence and type of the intermediate accessory are described.

The lens CPU in the embodiment of the present invention has a mechanism for detecting the presence / absence and type of an intermediate accessory, and the lens CPU detects the command signal terminal L. of the lens CPU at a predetermined timing. The presence / absence and type of the intermediate accessory is detected by reading and determining the state of the CMD. Based on the detection result, lens specific information obtained by performing correction calculation on the lens specific information according to the characteristics of the intermediate accessory is transmitted to the camera CPU. A mechanism that can detect the presence / absence and type of an intermediate accessory and correction calculation for lens specific information will be described later.

Further, the detection result when the interchangeable lens L is directly attached to the camera body B described above is determined as “no intermediate accessory”, and the lens specific information is not subjected to correction calculation. That is, the lens specific information is transmitted to the camera body B as it is.

Next, an outline of data communication when the intermediate accessory A is interposed between the camera body B and the interchangeable lens L will be described with reference to FIG.

In FIG. 2, the left side of the alternate long and short dash line shows the circuit of the camera body B, the right side shows the circuit of the interchangeable lens L, and the center shows the circuit of the intermediate accessory A. The circuit of the intermediate accessory A interposed between the camera body B and the interchangeable lens L works like an extension cable, and the camera body B and the interchangeable lens L are directly attached to the camera CPU and the lens CPU. Just like when it is connected. That is, the outline of the data communication in the configuration of FIG. 2 is the same as when the camera body B and the interchangeable lens L are directly mounted, and thus the description thereof is omitted.

Even when the intermediate accessory A is interposed between the camera body B and the interchangeable lens L in FIG. 2, a camera battery BT is provided in the camera body B, and the camera battery BT to the camera CPU power input terminal B. Power is supplied to VDD. The camera body B and the intermediate accessory A, and the intermediate accessory A and the interchangeable lens L are connected by a mount, and the camera battery BT is a power input terminal of the lens CPU via the MOSFET in the camera and the wiring in the intermediate accessory A. L. Connected to VDD. Further, the camera battery BT is connected to the power input terminal A. of the intermediate accessory CPU in the intermediate accessory A via the camera MOSFET. Connected to VDD. When a power switch (not shown) connected to the camera CPU is turned on or a release switch (not shown) is turned on, the camera body CPU is connected to the power control terminal B.E. VCNT is set to “Hi”. Then, the MOSFET in the camera conducts current, and from the camera battery BT via the mount contact terminal, the power input terminal L.L. To the VDD and at the same time the power input terminal A. of the intermediate accessory CPU. Power is supplied to VDD. A ground terminal B. having a common ground for the camera CPU, the lens CPU, and the intermediate accessory CPU. GND, L.M. GND and A.I. A GND is provided.

As shown in FIG. 2, the communication enable signal ENBL from the camera CPU is connected to the communication enable signal terminal L. of the lens CPU. ENBL is transmitted to the lens CPU, and at the same time, in the intermediate accessory A, the communication enable signal terminal A. It is transmitted from ENBL to the intermediate accessory CPU. A communication command signal CMD from the camera CPU is input to one input of a selector SEL having a function of two inputs and one output in the intermediate accessory A, and a command signal CMD from the intermediate accessory CPU is input to the other input of the selector SEL. Have been entered. From the output of the selector SEL, the command signal terminal L. The communication command signal CMD selected by the selector SEL is transmitted to the CMD. The selector control signal SCNT for selecting one input from the two inputs of the selector SEL is the selector control signal terminal A. Output from SCNT.

Next, an outline of an analog electric signal output method in which the intermediate accessory CPU in the embodiment of the present invention transmits information on the presence / absence and type of the intermediate accessory to the lens CPU will be described.

First, when the intermediate accessory A is supplied with power from the camera body B, the intermediate accessory CPU is activated. The intermediate accessory CPU sets the selector control signal SCNT for selecting one input from the two inputs of the selector SEL to “Low”, disconnects the command signal CMD input from the camera CPU to the selector SEL, and is input to the other of the selector SEL. The command signal CMD from the intermediate accessory CPU is selected. Then, the intermediate accessory CPU is connected to the command signal terminal A. An analog electrical signal indicating the presence and type of the intermediate accessory is output from the CMD. Therefore, from the output of the selector SEL, the command signal terminal L. An analog electrical signal is transmitted to the CMD. The lens CPU has a command signal terminal L.P. In the CMD, the command signal terminal A. of the intermediate accessory CPU. An analog electric signal indicating the presence and type of the intermediate accessory output from the CMD is detected at a predetermined timing.

Next, transmission of the command signal CMD from the camera CPU when starting data communication between the camera CPU and the lens CPU will be described.

B. Communication enable signal terminal B. of camera body CPU ENBL to lens CPU communication enable terminal L. The communication enable signal ENBL output to the ENBL is a signal for transmitting to the interchangeable lens L that the camera body B starts data communication, and is “Hi” before the data communication starts, and “Low” during the data communication. It becomes. Further, in the intermediate accessory A, A. of the intermediate accessory CPU. The communication enable signal ENBL is also transmitted to the ENBL, and similarly to the lens CPU, the intermediate accessory CPU monitors the timing when the communication enable signal ENBL changes from “Hi” to “Low”.

The intermediate accessory CPU has a communication enable signal terminal A. When the timing at which ENBL changes from “Hi” to “Low” is detected, a selector control signal SCNT for selecting one input from two inputs of the selector SEL is transmitted as a “Hi” signal. Then, the command signal terminal B. The input from the CMD to the selector SEL is the command signal terminal L. of the lens CPU. The command signal terminal A. of the intermediate accessory CPU connected to the CMD. The input from the CMD to the selector SEL is disconnected. Therefore, the command signal CMD from the camera CPU is sent to the command signal terminal L. of the lens CPU via the selector SEL. It is transmitted to CMD. The lens CPU has a command signal terminal L.P. The CMD receives a command signal CMD from the camera CPU.

Next, an analog electrical signal output method in which the intermediate accessory CPU indicates the presence and type of the intermediate accessory will be described in detail with reference to FIG.

FIG. 7 shows a command signal terminal A. of the intermediate accessory CPU. An analog electrical signal indicating the presence and type of the intermediate accessory output from the CMD is sent to the command signal terminal L. of the lens CPU. The example of a signal transmitted to CMD is shown.

In FIG. 7, first, the power input terminals A. VDD and the power input terminal L. of the lens CPU. When power is supplied to the VDD from the camera battery BT, both power input terminals A.V. VDD, L. The VDD changes from “Low” to “Hi”. The intermediate accessory CPU and the lens CPU are each activated when power is supplied from the camera battery BT.

The intermediate accessory CPU is connected to the command signal terminal A. Output of an analog electrical signal indicating the presence and type of the intermediate accessory is started from the CMD. In addition, the communication enable signal terminal A. In ENBL, the timing of changing from “Hi” to “Low” is monitored. Then, after a predetermined time, the intermediate accessory CPU finishes outputting the analog electric signal indicating the presence and type of the intermediate accessory, and the selector control signal terminal A. The selector control signal SCNT for switching the input connection from SCNT is changed from “Low” to “Hi”.

For example, in the case of FIG. 7B in which a 1.4 × rear converter, which is an intermediate accessory A, is interposed between the camera body B and the interchangeable lens L, the intermediate accessory CPU is within a predetermined time from activation. The command signal terminal A. A voltage corresponding to VDD × 2/3 volts is output from the CMD as an analog electric signal.

In the case of FIG. 7 (3) in which a double rear converter, which is an intermediate accessory A, is interposed between the camera body B and the interchangeable lens L, the intermediate accessory CPU is within a predetermined time from the start-up. Command signal terminal A. A voltage corresponding to VDD × 1/3 volt is output as an analog electric signal from the CMD.

The lens CPU is connected to the intermediate accessory CPU as in the above example. At the time when the analog electric signal is output from the CMD, the command signal terminal L. An analog electrical signal transmitted to the CMD is detected at a predetermined timing to determine the presence and type of the intermediate accessory. For example, the lens CPU transmits the analog electrical signal transmitted from the intermediate accessory CPU to the command signal terminal L. of the lens CPU at a timing T1 = 25 us after the intermediate accessory type signal output start time in FIG. Detected by CMD and A / D converted.

The analog electrical signal is A / D converted, and the presence / absence and type of the intermediate accessory is discriminated by a rule as shown in FIG. 7, for example. That is, in the case of FIG. 7A in which the intermediate accessory itself is not interposed and the interchangeable lens L is directly attached to the camera body B, there is no intermediate accessory CPU that outputs an analog electrical signal. Command signal terminal B. In the case of FIG. 7 (2) in which a voltage equivalent to VDD volt output from the CMD is detected and a 1.4 × rear converter is interposed, a voltage equivalent to VDD × 2/3 volt is detected and doubled. In the case of FIG. 7C in which a rear converter is interposed, a voltage corresponding to VDD × 1/3 volt is detected. For example, when VDD is 5 volts and power is supplied, the case of FIG. 7 (1) corresponds to 5 volts, the case of FIG. 7 (2) corresponds to 3.3 volts, and FIG. In this case, a voltage corresponding to 1.7 volts is detected.

As described above with reference to FIG. 7, during the time from the start of power supply to the intermediate accessory CPU and the lens CPU to the start of data communication between the camera CPU and the lens CPU, the intermediate accessory CPU receives the command signal terminals A.D. An analog electrical signal indicating the presence and type of the intermediate accessory is output from the CMD. Therefore, the interchangeable lens can determine the presence / absence and type of the intermediate accessory based on the analog electrical signal from the intermediate accessory CPU to the lens CPU without adding a new electrical contact or via the camera CPU. .

Further, the present invention is different from the intermediate accessory previously proposed in Japanese Patent Application No. 2008-217340 by the present applicant, and the intermediate accessory type signal c is not represented by binary values of “Hi” and “Low”, but is analog. In order to indicate the voltage value of the electric signal, the command signal terminal L. The detection of the CMD can be performed only once, and the intermediate accessory type signal c can be determined in a short time. Therefore, according to the present invention, the camera body B and the interchangeable lens L can be recognized later even in a camera system in which the time from the start of the camera CPU, the lens CPU, and the intermediate accessory to the start of data communication between the camera CPU and the lens CPU is short. Intermediate accessories A can be developed.

Next, referring to FIG. 6, 8-bit serial synchronous three-wire bidirectional communication when a 1.4 × rear converter, which is a kind of intermediate accessory A, is interposed between the camera body B and the interchangeable lens L. A signal example and a mechanism by which the lens CPU can detect the presence / absence and type of the intermediate accessory A will be described.

When the intermediate lens A is not provided and the interchangeable lens L is directly attached to the camera body B, the command signal terminal B. CMD is the command signal terminal L. of the lens CPU. Since it is directly connected to CMD, both command signal terminals B. CMD, L.C. CMD indicates the same signal. However, when the intermediate accessory A is interposed between the camera body B and the interchangeable lens L, the command signal terminal B. Command signal terminal L. of CMD and lens CPU. The CMD is temporarily disconnected, and instead the command signal terminal A. of the intermediate accessory CPU is used. Command signal terminal L. of CMD and lens CPU. CMD is connected. As a result, the command signal terminals A. From the CMD, the command signal terminal L. of the lens CPU. An analog electrical signal is transmitted to the CMD. Therefore, in FIG. 6 showing a signal example of 8-bit serial synchronous three-wire bidirectional communication when the intermediate accessory A is interposed between the interchangeable lens L and the camera body B, the command signal terminal B of the camera CPU is shown in FIG. . In addition to the CMD, the command signal terminal L. of the lens CPU. A signal example of CMD is also shown.

In FIG. 6, first, the camera CPU is connected to the power control terminal B.P. When VCNT is set to “Hi”, the MOSFET in the camera passes current, and the camera battery BT supplies power to the intermediate accessory CPU and the lens CPU. At the start timing, the intermediate accessory CPU sends a “Low” signal as the selector control signal SCNT to the selector SEL, and the command signal terminal B. Command signal terminal L. of CMD and lens CPU. Disconnect the connection with the CMD and instead use the command signal terminal A. of the intermediate accessory CPU. Command signal terminal L. of CMD and lens CPU. Connect to CMD. Further, the lens CPU recognizes this timing as the intermediate accessory type signal output start time, and after a predetermined time from the intermediate accessory type signal output start time, the lens CPU command signal terminal L. A voltage value is detected in the CMD. The lens CPU determines from the voltage value that the intermediate accessory A interposed is a 1.4 × rear converter. As described with reference to FIG. 7, when the intermediate accessory A interposed between the interchangeable lens L and the camera body B is a 1.4 × rear converter, the intermediate accessory CPU is connected to the command signal terminal A. . A voltage value corresponding to VDD × 2/3 volts is continuously output from the CMD as an analog electrical signal indicating the presence and type of the CMD from the start of the intermediate accessory type signal output.

The lens CPU receives the command signal terminals L.P. The analog electrical signal transmitted to the CMD is A / D converted, and the presence / absence and type of the intermediate accessory are determined based on the voltage value. In an example in which a 1.4 × rear converter is installed, the lens CPU detects a voltage equivalent to VDD × 2/3 volts, and determines that a 1.4 × rear converter is installed.

After the lens CPU determines the presence / absence and type of the intermediate accessory, the camera CPU detects that the communication enable signal terminal B. At the timing when ENBL is changed from “Hi” to “Low”, the intermediate accessory CPU ends the output of the analog electrical signal indicating the presence and type of the intermediate accessory. After the output of the analog electrical signal is finished, the command signal terminal A. Command signal terminal L. of CMD and lens CPU. The connection with the CMD is disconnected and the command signal terminal B. of the camera CPU is disconnected. Command signal terminal L. of CMD and lens CPU. CMD is connected. As a result, the command signal CMD is output from the camera CPU to the lens CPU.

The lens CPU is connected to the command signal terminal L.P. In the CMD, the analog electrical signal is detected and A / D converted at the timing when the camera battery BT starts output of the intermediate accessory type signal from which power is supplied to the intermediate accessory CPU. ENBL is changed from “Hi” to “Low” until the data communication start timing, and the intermediate accessory CPU is connected to the command signal terminal A. Any time can be set as long as an analog electric signal is output from the CMD.

The camera CPU has a communication enable signal terminal B.B. After ENBL is changed from “Hi” to “Low” to signal the start of data communication, a command signal CMD requesting lens data from the lens CPU is set in the communication output register, and communication for 8 bits is automatically performed. The clock signal CLK is connected to the communication clock signal terminal B. of the camera CPU. Output from CLK. The command signal CMD is transmitted 8 bits at a time from the camera CPU to the lens CPU in synchronization with the communication clock signal CLK.

When the lens CPU receives the communication clock signal CLK and the command signal CMD from the camera CPU, the lens CPU determines what lens specific information corresponds to the command signal CMD requested by the camera CPU, and the ROM in which the lens specific information is stored. The lens unique information stored in advance in the ROM in the lens CPU is read with reference to the address.

Here, if it is detected that there is an intermediate accessory before the 8-bit serial synchronous three-wire bidirectional communication is performed, a correction calculation corresponding to the characteristic of the intermediate accessory is performed on the lens specific information. The lens CPU performs lens correction information that has been subjected to correction calculation, and is transmitted to the camera CPU. In an example in which a 1.4 × rear converter is interposed, correction calculation according to the characteristics of the 1.4 × rear converter is performed on the lens specific information.

When the lens specific information subjected to the correction calculation according to the characteristics of the 1.4 × rear converter is set in the communication output register, the communication clock signal for 8 bits is transmitted from the camera CPU after a predetermined time from the communication clock signal terminal B.B. The lens CPU outputs the communication clock signal terminal L.L. When the communication clock signal CLK is received from the CLK, the 8-bit lens specific information subjected to the correction calculation is transmitted to the camera CPU as the answer signal ANS in synchronization with the communication clock signal CLK. The correction calculation method will be described in detail later using a flowchart.

Here, when the intermediate accessory A is interposed between the camera body B and the interchangeable lens L, the description about the detection method of the presence / absence and type of the 8-bit serial synchronous three-wire bidirectional communication and the intermediate accessory is summarized. According to the present invention, the intermediate accessory CPU of the intermediate accessory A has a function of outputting an analog electric signal indicating the presence and type of the intermediate accessory, and the lens CPU of the interchangeable lens L includes the camera of the camera body B. It is determined what lens specific information is requested by the camera CPU corresponding to the command signal CMD transmitted from the CPU, the lens specific information stored in the lens CPU is read in advance, and the intermediate accessory A is not interposed. Is detected, the lens-specific information is transmitted to the camera CPU as it is, and the intermediate accessory A is When it is detected that the lens has been detected, the lens specific information is subjected to a correction calculation according to the characteristics of the intermediate accessory A, and the lens specific information that has been corrected is transmitted to the camera CPU. The presence and type of the intermediate accessory only by transmission between the lens and the intermediate accessory A, and the lens-specific information most suitable for the combination of the interchangeable lens L and the intermediate accessory A is transmitted from the interchangeable lens L to the camera body B. Can do.

As another embodiment, the lens CPU does not perform correction calculation on the lens specific information stored in the lens CPU at the time of data communication with the camera CPU, but correction corresponding to the type of the intermediate accessory A that is expected to be mounted. Both lens-specific information that has been pre-calculated and lens-specific information that has not been corrected are stored in the ROM of the lens CPU, and the lens-specific information that meets the conditions depending on the presence and type of the detected intermediate accessory. The information may be read from the ROM in the lens CPU by referring to the ROM address and transmitted to the camera CPU.

The lens-specific information that has been subjected to the correction calculation and the lens-specific information that has not been subjected to the correction calculation are, for example, as shown in the correspondence table of FIG. Lens specific information when directly attached to the lens is stored from the ROM address 100, and lens correction information preliminarily corrected when a 1.4x rear converter is installed is stored from the ROM address 110, and the double rear When the converter is interposed, lens-specific information that has been subjected to correction calculation in advance is stored from the ROM address 120, and the lens CPU receives the command signal CMD requesting lens-specific information from the camera CPU. Depending on the presence and type of the identified intermediate accessory, lens specific information that meets the conditions With reference to the ROM address read from the ROM in the lens CPU, say a lens specific information transmitted to the camera CPU.

In general, in a camera system in which lenses can be exchanged, the types of intermediate accessories A are extremely small compared to the types of interchangeable lenses L, and the types of intermediate accessories A that will be mounted in the future when the interchangeable lenses L are produced are easy. Since it is predictable, it is possible to employ other embodiments described above. In addition, when the camera system, the interchangeable lens L, and the intermediate accessory A of the present invention are adopted and the aspect of the other embodiments described above is adopted, a new type of intermediate accessory A is produced after the interchangeable lens L is put on the market. However, it is possible to easily deal with a new type of intermediate accessory A by updating the firmware of the interchangeable lens L or the like.

Next, the operation of the lens CPU for correcting and calculating the lens unique information stored in the lens CPU of the interchangeable lens L will be described using the flowcharts of FIGS. 9 and 10.

In FIG. 9, first, a power input terminal L.P. When power is supplied from VDD, the operation of the lens CPU is started, and processing generally called initial setting such as setting of input / output of each terminal, setting of a time monitoring timer, and setting of communication is performed in # 101. When the intermediate accessory A is interposed, the power is supplied to the intermediate accessory A at the same time as the power supply to the lens CPU. At this timing, the intermediate accessory CPU indicates the presence and type of the intermediate accessory. The signal output has started. The detailed operation in which the intermediate accessory A outputs an analog electric signal indicating the presence and type of the intermediate accessory will be described later.

In the next # 102, it waits for 5us time. In step # 102, the time is adjusted so that the total processing time from when the camera body B is turned on until the next A / D conversion is 25 us. Step # 102 waiting for time may be arbitrarily set according to the total processing time until A / D conversion.

In the next step # 103, at the timing when 25 us elapses after the camera body B is turned on, the lens CPU sends the command signal terminal L.P. The analog electric signal transmitted to the CMD is A / D converted, and the obtained voltage value is stored in the RAM in the lens CPU as an intermediate accessory type signal c.

Next, in # 104, the lens CPU monitors the timing when the communication enable signal ENBL changes from “Hi” to “Low”. When ENBL changes from “Hi” in the normal state to “Low” to recognize the start of data communication of the camera CPU, the process proceeds to the next # 105.

In # 105, a communication mode for starting 8-bit serial synchronous three-wire bidirectional communication is set. In step # 106, the command signal CMD transmitted from the camera CPU in synchronization with the communication clock signal CLK is received.

Next, in # 107, it is determined whether or not the command signal CMD received in # 106 is an information identification code request (AC). The ROM address 100h where the information identification code (AI) is stored is stored in the memory adr of the RAM in the lens CPU with reference to the correspondence table, and the process proceeds to # 117.

In # 109, it is determined whether or not the command signal CMD received in # 106 is a function code request (BC). If it is a function code request (BC), refer to the correspondence table of FIG. 3 in # 110. The ROM address 101h where the function code (BI) is stored is stored in the memory adr of the RAM in the lens CPU, and the process proceeds to # 117.

In # 111, it is determined whether or not the command signal CMD received in # 106 is an open aperture value request (CC). If the command signal CMD is an open aperture value request (CC), the correspondence table of FIG. The ROM address 102h in which the maximum aperture value (CI) is stored is stored in the memory adr of the RAM in the lens CPU, and the process proceeds to # 117.

In step # 113, it is determined whether or not the command signal CMD received in step # 106 is a focal length request (DC). If the command signal CMD is a focal length request (DC), the correspondence table in FIG. Then, the ROM address 103h in which the focal length (DI) is stored is stored in the memory adr of the RAM in the lens CPU, and the process proceeds to # 117.

In # 115, it is determined whether or not the command signal CMD received in # 106 is a conversion coefficient request (EC). If the command signal CMD is a conversion coefficient request (EC), refer to the correspondence table of FIG. 3 in # 116. The ROM address 104h where the conversion coefficient (EI) is stored is stored in the RAM memory adr in the lens CPU, and the process proceeds to # 117.

Next, in # 117, the ROM address stored in the memory adr of the RAM in the lens CPU is read, the lens specific information corresponding to the ROM address is read from the ROM in the lens CPU, and the lens specific information is read from the lens CPU. Is stored in the memory data1 of the internal RAM. Accordingly, lens specific information corresponding to the command signal CMD transmitted from the camera CPU can be stored in data1.

Next, in step # 118, a correction calculation subroutine corresponding to the characteristics of the intermediate accessory A is applied to the lens specific information stored in the memory data1 of the RAM in the lens CPU according to the presence and type of the intermediate accessory. Run. Details of the correction calculation subroutine will be described later.

Next, in # 119, the lens CPU obtains the lens unique information that has been subjected to the correction calculation in # 118 and the lens unique information that has not been subjected to the correction calculation without the intermediate accessory A, and the intermediate accessory A is provided. The data is transmitted to the camera CPU as an answer signal ANS to complete the data communication. Thereafter, the process returns to # 104 to monitor the start of the next data communication.

Here, with reference to the flowcharts of FIGS. 12 and 13, a method in which the intermediate accessory CPU of the various intermediate accessories A outputs an analog electrical signal indicating the presence and type of the intermediate accessory will be described.

12 shows that the intermediate accessory CPU of the 1.4 × rear converter described with reference to FIG. It is a flowchart output from CMD.

In FIG. 12, first, the power input terminals A. When power is supplied from VDD, the operation of the intermediate accessory CPU is started, and processing generally called initial setting such as input / output setting of each terminal and setting of a time monitoring timer is performed in # 301.

In # 302, when the intermediate accessory type signal output is started, the intermediate accessory CPU sets the “Low” signal as the selector control signal SCNT for selecting one input from the two inputs of the selector SEL. Output from SCNT. As a result, the command signal terminal B. The command signal terminal L. of the interchangeable lens CPU from the CMD. The connection to the CMD is disconnected, and the command signal terminal A. The command signal terminal L. of the interchangeable lens L from the CMD. Connect to CMD.

In # 303, the intermediate accessory CPU of the 1.4 × rear converter outputs a voltage equivalent to VDD × 2/3 volts as an analog electric signal indicating the presence and type. The analog electrical signal is sent from the command signal terminal A. of the intermediate accessory CPU. The command signal terminal L. of the lens CPU from the CMD. It is transmitted to CMD. The lens CPU has a command signal terminal L.P. In the CMD, an analog electrical signal is detected at a predetermined timing, and the presence and type of an intermediate accessory are determined.

In the next # 304, the intermediate accessory CPU monitors the timing at which the communication enable signal ENBL changes from “Hi” to “Low”. When ENBL changes from “Hi” in the normal state to “Low”, the camera CPU recognizes the start of data communication, and proceeds to the next # 305.

In # 305, the intermediate accessory CPU recognizes the time when the communication enable signal ENBL changes from “Hi” to “Low” as the intermediate accessory type signal output end time, and selects the selector input from the two inputs of the selector SEL. As the signal SCNT, a signal of “Hi” is selected as the selector control signal terminal A. Output from SCNT. As a result, the command signal terminal B. The command signal terminal L. of the lens CPU from the CMD. The command signal terminal A. of the intermediate accessory CPU connected to the CMD. The command signal terminal L. of the lens CPU from the CMD. Disconnect from CMD. And the command signal terminal B. of the camera CPU. The command signal terminal L. of the lens CPU from the CMD. A command signal CMD is transmitted to the CMD. The lens CPU has a command signal terminal L.P. In the CMD, the command signal CMD from the camera CPU is received.

When the process proceeds to the next step # 306, the intermediate accessory CPU has finished the role of outputting the analog electric signal indicating the presence and type of the intermediate accessory CPU. stand by.

FIG. 13 is a flowchart in which the intermediate accessory CPU of the double rear converter described in FIG. 7 outputs an intermediate accessory type signal c indicating the type.

In FIG. 13, first, the power input terminals A. When power is supplied from VDD, the operation of the intermediate accessory CPU is started, and processing generally called initial setting such as input / output setting of each terminal and setting of a time monitoring timer is performed in # 401.

In # 402, at the time when the intermediate accessory type signal output starts, the intermediate accessory CPU sets a signal “Low” as the selector control signal SCNT for selecting one input from the two inputs of the selector SEL to the selector control signal terminal A. # 402. Output from SCNT. As a result, the command signal terminal B. The command signal terminal L. of the interchangeable lens CPU from the CMD. The connection to the CMD is disconnected, and the command signal terminal A. The command signal terminal L. of the interchangeable lens L from the CMD. Connect to CMD.

In # 403, the intermediate accessory CPU of the double rear converter applies a voltage equivalent to VDD × 1/3 volts as an analog electric signal indicating the presence and type of the double rear converter to the command signal terminal A.D. Output from CMD. The analog electrical signal is sent from the command signal terminal A. of the intermediate accessory CPU. The command signal terminal L. of the lens CPU from the CMD. It is transmitted to CMD. The lens CPU has a command signal terminal L.P. In the CMD, an analog electrical signal is detected at a predetermined timing, and the presence and type of an intermediate accessory are determined.

Next, in # 404, the intermediate accessory CPU monitors the timing at which the communication enable signal ENBL changes from “Hi” to “Low”, and the communication enable signal terminal A. When ENBL changes from “Hi” in the normal state to “Low”, the camera CPU recognizes the start of data communication and proceeds to the next # 405.

In # 405, the intermediate accessory CPU recognizes the time when the communication enable signal ENBL changes from “Hi” to “Low” as the intermediate accessory type signal output end time, and selects the selector SEL from two inputs of the selector SEL. As the signal SCNT, a signal of “Hi” is selected as the selector control signal terminal A. Output from SCNT. As a result, the command signal terminal B. The command signal terminal L. of the lens CPU from the CMD. The command signal terminal A. of the intermediate accessory CPU connected to the CMD. The command signal terminal L. of the lens CPU from the CMD. Disconnect from CMD. And the command signal terminal B. of the camera CPU. The command signal terminal L. of the lens CPU from the CMD. A command signal CMD is transmitted to the CMD. The lens CPU has a command signal terminal L.P. In the CMD, the command signal CMD from the camera CPU is received.

When the next step # 406 is reached, the intermediate accessory CPU has finished the function of outputting the analog electric signal indicating the presence and type of the intermediate accessory CPU. Therefore, the intermediate accessory CPU shifts to the low current consumption mode and loops until the power supply is stopped at # 407. stand by.

Next, FIG. 10 is a flowchart for explaining the correction calculation subroutine of FIG. 9 # 120, and is a flowchart for performing correction calculation according to the presence / absence and type of the intermediate accessory on the lens specific information.

In FIG. 10, first in # 201, it is determined whether or not the intermediate accessory type signal c stored in the RAM of the lens CPU is equal to or higher than VDD × 2.5 / 3 volts. If it is equal to or higher than VDD × 2.5 / 3 volts, it is determined that “the intermediate accessory A is not provided”, and it is not necessary to perform correction calculation on the lens specific information, so the process proceeds to # 206 and the correction calculation subroutine is completed. Returning to the main flowchart of FIG. If it is less than VDD × 2.5 / 3 volts, the process proceeds to the next # 202.

In # 202, it is determined whether or not the intermediate accessory type signal c stored in the RAM of the lens CPU is equal to or higher than VDD × 1.5 / 3 volts. If it is equal to or higher than VDD × 1.5 / 3 volts, it is determined that “1.4 × rear converter is present”, and in # 204, the ROM address stored in the memory adr of the RAM in the lens CPU is set to 100. Is added. By referring to the ROM address in which 100 is added to adr, the correction value corresponding to the characteristics of the 1.4 × rear converter can be read from the ROM as shown in the correspondence table of FIG. The read correction value is stored in the memory data2 of the RAM in the lens CPU, and the process proceeds to the next # 205.

If it is less than VDD × 1.5 / 3 volts, it is determined that “a double rear converter is present”, and in # 203, 200 is added to the ROM address stored in the memory adr of the RAM in the lens CPU. . Referring to the ROM address in which 200 is added to adr, the correction value corresponding to the characteristics of the double rear converter can be read from the ROM as shown in the correspondence table of FIG. The read correction value is stored in the memory data2 of the RAM in the lens CPU and proceeds to the next # 205.

In # 205, the lens specific information already stored in the memory data1 in # 119 of FIG. 9 and the correction value corresponding to the characteristic of the intervening intermediate accessory A stored in the data2 in # 204 or # 203, And the solution is stored in data1. Thereafter, the process proceeds to # 206, the correction calculation subroutine is terminated, and the process returns to the main flowchart of FIG.

In the correction calculation subroutine described above, the lens CPU first reads lens specific information corresponding to the command signal CMD received from the camera CPU from the ROM of the lens CPU, and performs correction corresponding to the presence and type of the intermediate accessory determined by the lens CPU. The ROM address where the value is stored is determined, the correction value is read out from the ROM in the lens CPU by referring to the ROM address, and the correction value is added to the lens specific information to obtain the lens specific information. Correction calculation according to the characteristics of the intermediate accessory A can be performed.

(Other examples)
Next, another embodiment of the correction calculation subroutine will be described with reference to FIG. The other embodiment is characterized by the correction calculation subroutine of FIG. 11, and the main flowchart is the same as that of FIG. 9, so only the correction calculation subroutine of FIG. 11 will be described.

FIG. 11 replaces the correction calculation subroutine of FIG. 10 described above. The lens specific information and the lens specific information on which correction calculation corresponding to the characteristics of various intermediate accessories A assumed to be interposed are performed in advance. FIG. 5 is a flowchart for reading lens specific information in accordance with the presence / absence and type of an intermediate accessory stored in a ROM in the lens CPU.

In FIG. 11, first in # 251, it is determined whether or not the intermediate accessory type signal c stored in the RAM is equal to or higher than VDD × 2.5 / 3 volts. If it is equal to or higher than VDD × 2.5 / 3 volts, it is determined that “the intermediate accessory A is not provided”, and there is no need to correct the lens-specific information, and the lens already stored in data1 in # 119 Since it is sufficient to return the unique information to the camera CPU as it is, the process proceeds to # 255 to end the correction calculation subroutine and returns to the main flowchart of FIG. If it is less than VDD × 2.5 / 3 volts, the process proceeds to the next # 252.

In # 252, it is determined whether or not the intermediate accessory type signal c stored in the RAM is equal to or higher than VDD × 1.5 / 3 volts. If it is equal to or higher than VDD × 1.5 / 3 volts, it is determined that “1.4 × rear converter is present”, and in # 254, 10 is added to the ROM address stored in the memory adr of the RAM in the lens CPU. to add. Referring to the ROM address in which 10 is added to adr, lens specific information that has been subjected to a correction operation in accordance with the characteristics of the 1.4 × rear converter in advance can be read from the ROM, for example, as shown in the correspondence table of FIG. . The read lens-specific information that has been subjected to the correction calculation is stored in the memory data1 of the RAM in the lens CPU, the process proceeds to the next # 255, the correction calculation subroutine is terminated, and the process returns to the main flowchart of FIG.

If it is less than VDD × 1.5 / 3 volts, it is determined that “there is a double rear converter intervening”, and in # 253, 20 is added to the ROM address stored in the memory adr of the RAM in the lens CPU. Referring to the ROM address in which 20 is added to adr, lens specific information that has been subjected to a correction operation in advance according to the characteristics of the double rear converter can be read from the ROM as shown in the correspondence table of FIG. The read lens-specific information that has been subjected to the correction calculation is stored in the memory data1 of the RAM in the lens CPU, the process proceeds to the next # 255, the correction calculation subroutine is terminated, and the process returns to the main flowchart of FIG.

In the correction calculation subroutines of the other embodiments described above, the lens CPU does not perform the correction calculation of the lens specific information every time the command signal CMD is received from the camera CPU, but various types of lens specific information and intervention are assumed. The lens specific information that has been subjected to the correction calculation corresponding to the characteristics of the intermediate accessory A is stored in advance in the ROM in the lens CPU, and the lens specific information is determined based on the presence and type of the intermediate accessory. Since the data is read, the correction calculation procedure can be omitted.

In step # 201 in FIG. 10 or step # 251 in FIG. 11, it is determined whether or not the intermediate accessory type signal c stored in the RAM is equal to or higher than VDD × 2.5 / 3 volts. When the voltage is 5/3 volts or more, it is determined that “the intermediate accessory A is not interposed”. This is because the command signal terminal B. of the camera CPU is in a period from when the camera battery BT starts supplying power to the lens CPU until data communication is started. This is because the embodiment has been described on the assumption that the voltage level of the CMD is generally “Hi”. Accordingly, since the “Hi” state corresponds to VDD at the voltage level, the description has been given using VDD × 2.5 / 3 volts as the determination threshold.

Naturally, contrary to the setting of the present embodiment, due to the design of the camera body, the command signal terminal B of the camera CPU is started after the camera battery BT starts supplying power to the lens CPU until the data communication is started. . The voltage level of the CMD may be set to “Low”. In this case, since the “Low” state corresponds to 0 volt at the voltage level, the determination threshold is set to VDD × 0.5 / 3 volt, and less than VDD × 0.5 / 3 volt is “intermediate accessory A is not installed. It will be judged.

The command signal terminal B. of the camera CPU from when the camera battery BT starts supplying power to the lens CPU until data communication is started. A camera system in which a camera body having a specification with a CMD voltage level “Hi” and a camera body having a specification with “Low” is mixed. In this case, those skilled in the art can easily implement the control flow according to the type of camera body by providing two determination threshold values for “no intervention of the intermediate accessory A”.

In the description of the present embodiment, the intermediate accessory CPU is provided in the intermediate accessory A and the intermediate accessory type signal c is generated. However, the element that generates the intermediate accessory type signal c is not limited to the CPU, and is a general-purpose discrete. Replacement with electrical components is also possible. As an example, only the function of the intermediate accessory A to generate the intermediate accessory type signal c will be described with reference to FIG.

The general-purpose discrete electrical component DS in the intermediate accessory A shown in FIG. 14 includes a NOT circuit, an OR circuit, a switching FET, a resistor R1, and a resistor R2. The NOT circuit and the OR circuit of the logic elements control the selector SEL and the switching FET.

When power is supplied from the camera battery BT to the camera CPU, the intermediate accessory CPU, and the lens CPU, the camera CPU receives the enable signal terminal B. A signal “Hi” is output from ENBL. The intermediate accessory CPU has an enable signal terminal A. The “Hi” signal is input from ENBL and inverted by a NOT circuit to be a “Low” signal. The OR circuit receives the “Low” signal, and outputs the “Low” signal based on the “Low” signal input at the time of starting the OR circuit.

The “Low” signal output from the OR circuit is the selector control signal terminal A. It is output from the SCNT to the selector SEL as the selector control signal SCNT and also to the switching FET in the general-purpose discrete electrical component DS. As a result, the selector SEL receives the command signal terminal B. of the lens CPU. The command signal terminal L. of the lens CPU from the CMD. The connection to the CMD is disconnected and the command signal terminal A. of the intermediate accessory CPU is disconnected. The command signal terminal L. of the lens CPU from the CMD. Connect to CMD (state of FIG. 14). The switching FET is connected to the power input terminal A. of the intermediate accessory CPU. Power supplied from VDD is supplied to the resistors R1 and R2. The voltage divided by R1 and R2 is the command signal terminal A. The command signal terminal L. of the lens CPU as an analog electrical signal from the CMD. It is transmitted to CMD.

Thereafter, in order to start data communication between the camera CPU and the lens CPU, an enable signal terminal B.B. When the “Low” signal is output from the ENBL, the intermediate accessory CPU sends the enable signal terminal A. The “Low” signal is input from ENBL and inverted by the NOT circuit to be “Hi”. The OR circuit receives a “Hi” signal, and outputs a “Hi” signal based on the “Low” signal input in the previous state.

The “Hi” signal output from the OR circuit is connected to the selector control signal terminal A. of the intermediate accessory A. The SCNT is output to the selector SEL as the selector control signal SCNT, and is also output to the switching FET. As a result, the selector SEL receives the command signal terminal A. The command signal terminal L. of the lens CPU from the CMD. The connection to the CMD is disconnected, and the command signal terminal B. The command signal terminal L. of the lens CPU from the CMD. Connect to CMD. The switching FET is connected to the power input terminal A. of the intermediate accessory CPU. Supply of power supplied from VDD to the resistors R1 and R2 is stopped. Thereby, data communication between the camera CPU and the lens CPU is started. In addition, when the output of the analog electric signal becomes unnecessary, the power consumption in the intermediate accessory A can be suppressed by cutting off the power supply to the resistors R1 and R2.

As described above, the present invention does not add an electrical contact to the interchangeable lens and the camera body, and cannot be applied by the invention described in Japanese Patent Application No. 2008-217340 from the time of supplying power to the lens CPU. Even if the camera system takes a short time to start data communication with the lens CPU, the interchangeable lens can recognize the presence and type of the intermediate accessory by analog electrical signals transmitted from the interchangeable lens to the intermediate accessory. Furthermore, the interchangeable lens can transmit lens-specific information optimum for the combination of the interchangeable lens and various intermediate accessories to the camera body in accordance with the information on the presence and type of the intermediate accessory. Further, in the configuration of the present invention, it is not necessary to add an electrical contact or an IC for correction calculation in the intermediate accessory, and the present invention can provide an intermediate accessory with reduced cost.

B Camera body L Interchangeable lens A Intermediate accessory MOSFET MOSFET
VCNT power control signal SEL selector SCNT selector control signal ENBL communication enable signal CMD command signal CLK communication clock signal ANS answer signal BT camera battery

Claims (7)

The interchangeable lens is detachable from the camera body, and an intermediate accessory is interposed between the interchangeable lens and the camera body, and between the interchangeable lens and the intermediate accessory and between the intermediate accessory and the camera. Each of the interchangeable lenses is electrically connected to the main body via a plurality of terminals provided in the same number , and the interchangeable lens is connected to the main body using a plurality of predetermined digital electric signals passing through the terminals. In a camera system that transmits lens-specific information to the camera body,
The camera body supplies power to the interchangeable lens and the intermediate accessory,
Intermediate accessory, between the power supply before starting communication, cutting the predetermined digital electrical signal to be transmitted from said camera body to said interchangeable lens, predetermined analog indicating whether the type of the intermediate accessory instead output to the interchangeable lens electrical signals through only the plurality of terminals, after the start of communication connects said prescribed digital electrical signal to be transmitted from said camera body to said interchangeable lens,
The interchangeable lens, between the power supply before starting communication recognizes the existence and type of the intermediate accessory by detecting the predetermined analog electric signals, after the start of communication in the presence and type of the intermediate accessory A lens system that transmits lens-specific information that has undergone a correction calculation in response to the camera body. 2. The camera system according to claim 1, wherein the lens-specific information that has been subjected to the correction calculation is obtained whenever the lens CPU of the interchangeable lens receives a command signal that requests lens-specific information from the camera CPU of the camera body. 2. The camera system according to claim 1, wherein the lens unique information is obtained by reading lens unique information stored in a storage area of a CPU and performing a correction operation according to the presence and type of an intermediate accessory. 2. The camera system according to claim 1, wherein the correction-specific lens-specific information is subjected to correction calculation in advance according to the presence / absence and type of the intermediate accessory, and is read from a storage area of the lens CPU. The camera system according to claim 1. The interchangeable lens is detachable with respect to the camera body or the intermediate accessory, and an intermediate accessory can be interposed between the interchangeable lens and the camera body, and between the interchangeable lens and the intermediate accessory and the intermediate accessory. And the camera body, or the interchangeable lens and the camera body are electrically connected through a plurality of terminals provided in the same number, and a plurality of terminals passing through the terminals. In an interchangeable lens constituting a camera system in which the interchangeable lens transmits lens specific information to the camera body using a predetermined digital electrical signal of
When the intermediate accessory is interposed between the interchangeable lens and the camera body,
The camera body supplies power to the interchangeable lens and the intermediate accessory,
Between the power supply and before the start of communication, the interchangeable lens receives the predetermined analog electrical signal indicating the presence and type of an intermediate accessory instead of the predetermined digital electrical signal with the camera body only for the plurality of terminals. The presence / absence and type of the intermediate accessory is recognized by detecting the intermediate accessory, and after the start of communication, the lens-specific information corrected according to the presence / absence and type of the intermediate accessory is sent to the camera body with the predetermined digital electrical information. Send by signal,
When the intermediate accessory is not interposed between the interchangeable lens and the camera body,
The camera body supplies power to the interchangeable lens,
The interchangeable lens recognizes that the intermediate accessory is not attached by detecting the predetermined signal transmitted from the camera body to the interchangeable lens between the time when the power is supplied and before the start of communication. An interchangeable lens, wherein the lens-specific information that is not yet transmitted is transmitted to the camera body. 5. The interchangeable lens according to claim 4, wherein the lens-specific information that has been subjected to the correction calculation is obtained whenever the lens CPU of the interchangeable lens receives a command signal that requests lens-specific information from the camera CPU of the camera body. 5. The interchangeable lens according to claim 4, wherein the lens-specific information is obtained by reading lens-specific information stored in a storage area of a CPU and performing a correction operation according to the presence and type of an intermediate accessory. 5. The interchangeable lens according to claim 4, wherein the lens-specific information that has been subjected to the correction calculation is preliminarily subjected to a correction calculation according to the presence / absence and type of the intermediate accessory, and is read from a storage area of the lens CPU. The interchangeable lens according to claim 4. It is detachable with respect to the camera body or the interchangeable lens, and an intermediate accessory can be interposed between the interchangeable lens and the camera body, between the interchangeable lens and the intermediate accessory, and between the intermediate accessory and the camera A plurality of predetermined terminals passing through the plurality of terminals are electrically connected to each other through a plurality of terminals provided between the main body or between the interchangeable lens and the camera body. In an intermediate accessory constituting a camera system in which the interchangeable lens transmits lens specific information to the camera body using a digital electrical signal,
The intermediate accessory disconnects the predetermined digital electric signal transmitted from the camera body to the interchangeable lens until the communication is started until the start of communication, and instead, a predetermined analog indicating the presence and type of the intermediate accessory The electrical signal is output to the interchangeable lens only through the plurality of terminals, the interchangeable lens is made aware of the presence and type of the intermediate accessory, and is transmitted from the camera body to the interchangeable lens after communication is started. An intermediate accessory that connects a digital electrical signal and causes the interchangeable lens to transmit to the camera body lens-specific information that is corrected according to the presence and type of the intermediate accessory.

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