JP3097175B2 - Camera and camera interchangeable lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detachable lens having a memory in which information relating to a lens is stored in a readable manner. The present invention relates to a camera body and an interchangeable lens of a controlled camera system.

[0002]

2. Description of the Related Art Conventionally, in a single-lens reflex camera, various types of interchangeable lenses are mounted on a camera body to constitute various camera systems. In such a camera system, the interchangeable lens stores lens data unique to the interchangeable lens, for example, data such as a focal length, an open F value, and a conversion coefficient (K value) for converting a defocus amount into a lens drive amount. The camera has a built-in memory, and the camera body controls the photographing operation based on the lens data read from the memory of the interchangeable lens.

[0003] In recent years, a new camera system incorporates not only the above-mentioned memory but also an actuator for driving the lens and a control circuit for the actuator on the interchangeable lens side, and combines an active interchangeable lens with the camera body. Is being developed. For example, a drive motor for the zoom lens and a drive control circuit for controlling the drive of the zoom lens are built in an interchangeable lens having a zoom lens, and the zoom lens is controlled by the drive control circuit while communicating data between central control circuits on the camera body side. An interchangeable lens having a so-called power zoom function in which a lens is driven by a motor has been developed.

[0004]

By the way, while the functions of the interchangeable lens and the camera body are improved to construct a new class of camera system, the interchangeable lens for the new system and the camera body for the old system or the new system are used. It is desirable that the camera body of the old and new systems can be connected to the interchangeable lens for the old system, and that the interchangeable lenses of the camera bodies of the old and new camera systems are provided.

However, in the above-mentioned conventional camera system, since the functions of the camera body are configured corresponding to the functions of the interchangeable lens, the camera body (or interchangeable lens) of the new system is replaced with the interchangeable lens (or interchangeable lens) of the old system. Camera body).

For example, an interchangeable lens of a new system having a power zoom function equipped with a drive motor and its control circuit transmits lens data stored in a memory in the interchangeable lens to a central control circuit in the camera body, The control circuit performs a zoom operation by controlling the drive of the drive motor while communicating data with the centralized control circuit, and these operations are performed based on a control signal from the centralized control circuit. . That is, the interchangeable lens switches a communication partner to a memory or a control circuit in accordance with a selection signal from the central control circuit.

On the other hand, when this interchangeable lens is mounted on the camera body of the old system, the central control circuit in the camera body sends out a data read signal from the memory and does not send out the selection signal. For this reason, there occurs a problem that the centralized control circuit cannot read the lens data from the memory.

Further, the camera body of the new system determines whether the interchangeable lens mounted is of the old system or of the new system. In the case of the old system, only the lens data reading control is performed, and In this case, the communication partner must be switched between the memory and the control circuit as needed, and two types of control of reading lens data and controlling driving of the zoom lens by data communication with the control circuit must be properly used. Control becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a camera which can be connected irrespective of the type of function of the interchangeable lens and an exchange which can be connected irrespective of the function of the camera body. It is intended to provide a lens.

[0010]

According to a first aspect of the present invention, there is provided a camera provided with an interchangeable lens having a memory in which information on a lens is readablely stored. First power output means for supplying a small-capacity power supply to the interchangeable lens side; second power supply output means for supplying a large-capacity power supply to the interchangeable lens side; Data input / output means for inputting / outputting data, and driving means for driving the interchangeable lens with the large-capacity power supply and driving control means for driving with the small-capacity power supply based on the read information on the lens. Determining means for determining whether or not there is a lens driving mechanism for driving a lens by the driving means based on the control of the driving control means; and If it is determined to have a mechanism, in which a control signal output means for outputting a predetermined communication control signal to the interchangeable lens to permit a communication between the drive control means.

According to a second aspect of the present invention, there is provided an exchange of a camera having a memory in which information on a lens is readablely stored, and wherein the information on the lens is read out to the camera by data communication with a mounted camera. A driving unit for driving the lens, a driving control unit for controlling driving of the driving unit, a first power supply input unit for inputting power supplied from the camera to the driving unit, Second power input means for inputting power supplied from the camera to the drive control means, data input / output means for inputting / outputting data between the cameras, and the drive means from the camera to the drive means. Determination means for determining the presence or absence of power supply, and determination that power has been supplied to the driving means, and that a predetermined communication control signal has been input from the camera side. , The power input from the second power supply means supplies to said drive control means, the communication partner of the camera is obtained and a communication control means for switching set in the drive control means.

[0012]

According to the first aspect of the present invention, a large capacity power supply for driving means for driving the lens from the camera side to the interchangeable lens side and a small capacity power supply for driving the drive control means of the driving means are supplied. Is done. In the interchangeable lens having the driving unit and the driving control unit, the driving unit is driven by the large-capacity power supply, and the driving control unit is driven by the small-capacity power supply.

When the interchangeable lens is mounted on the camera, information on the lens is read from the memory in the interchangeable lens via the data input / output means, and the interchangeable lens is driven by the driving means from the information on the lens. It is determined whether or not a driving mechanism is provided. When it is determined that the interchangeable lens has the lens driving mechanism, a predetermined communication control signal is output to the interchangeable lens, and a communication partner with the camera is switched from the memory to the drive control unit. You. Thereby, the camera performs data communication with the drive control means, and the drive of the lens can be controlled via the drive control means and the drive means.

On the other hand, when it is determined that the interchangeable lens does not have the lens driving mechanism, the communication partner with the camera is held in the memory.

According to the second aspect of the present invention, the lens is driven by the driving means based on the control of the driving control means.
The drive control unit and the drive unit are respectively driven by a power supply supplied from a camera. Then, when a predetermined communication control signal is input from the camera in a state where power is supplied from the camera to the driving means, the power supplied from the camera is guided to the driving control means to be activated, and further the camera and the Is switched from the memory to the drive control means.

That is, the interchangeable lens determines the type of the mounted camera based on whether or not power is supplied to the driving means, and sets a communication partner requested by the camera based on a communication control signal.

On the other hand, when power is not supplied from the camera to the drive means, the drive control means is not activated, and the communication partner with the camera is held in the memory.

[0018]

FIG. 1 is a system configuration diagram of a camera system including a camera and an interchangeable lens according to the present invention.

FIG. 1 shows a state in which the interchangeable lens LE is mounted on the camera BD. The power supply connection terminal and the data communication connection terminal are provided on both coupling surfaces of the camera BD and the interchangeable lens LE. Are normally in contact with each other.

In the figure, 11 to 18 are electrical contacts provided on the camera BD side, and 19 to 26 are electrical contacts provided on the interchangeable lens LE side. And (11,
19) and (17, 25) are electrical contacts for supplying power from the camera BD side to the interchangeable lens LE side. The electrical contacts 11, 19 are interface circuits 2 to be described later.
7 and an electrical contact for supplying power to the slave microcomputer 28. From the electrical contacts 11 and 19, a small-capacity power supply of, for example, a power supply voltage of 5 V is supplied.
The electric contacts 17 and 25 are connected to a zoom motor 3 described later.
This is an electrical contact for supplying a drive power supply for the drive circuit 29 of 0, and a large-capacity power supply of about several A is supplied.

Also, (12, 20) and (18, 26)
Are electrical contacts for a ground line provided corresponding to the two types of power supply systems. The electrical contacts 12 and 20 are for a small power line, and the electrical contacts 18 and 26 are for a large power line.

Further, (13, 21) to (16, 24)
Are electrical contacts for data communication between the camera BD and the interchangeable lens LE. The electric contacts 13 and 21 are connected to the camera body BD
And a chip select signal for designating a communication partner output from the camera to the interchangeable lens LE.
Are for a synchronous clock signal for inputting / outputting data, the electrical contacts 15 and 23 are for a data input line for inputting data from the interchangeable lens LE to the camera BD, and the electrical contacts 16 and 24 are for It is for a data output line for outputting data from the camera BD to the interchangeable lens LE.

Next, each circuit on the camera BD side and the interchangeable lens LE side will be described. In FIG. 1, the right part of the electrical contacts (11, 18) to (19, 26) shows the circuit configuration on the camera BD side, and the left part shows the circuit configuration on the interchangeable lens LE side.

On the camera BD side, reference numeral 1 denotes a DC / DC converter which generates a stable voltage (5V) from the battery voltage of the battery 3 which is a main power supply input to the input terminals IN1 and IN2, and outputs it from the VOUT terminal. Is what you do. This output voltage is supplied to each circuit as a power supply of an electric circuit in the camera BD, and the electric contacts 11, 1
9 through the interface circuit 2 in the interchangeable lens LE
7 and the slave microcomputer 28.

Reference numeral 2 denotes a camera BD, which is an interface circuit 27 and a slave microcomputer 28 in the interchangeable lens LE.
A central control circuit (hereinafter, referred to as a main microcomputer) that performs data communication with the microcomputer and controls the photographing operation of the camera. The main microcomputer 2 has a P01 terminal for detecting whether or not the interchangeable lens LE is attached, and the P01 terminal is connected to a contact on one side of a lens attachment detection switch 5 described later.

The main microcomputer 2 has a CSLNS terminal for outputting the chip select signal, an SCK terminal for outputting a synchronous clock, a SIN terminal for inputting data, and a SOUT terminal for outputting data. A VC1 terminal, which is connected to the contacts 12 to 15 and outputs a control signal of a power supply control circuit 4 described later, and V
C2 terminals, each having a CIB of the power supply control circuit 4
Terminal and the CIA terminal.

The power supply control circuit 4 includes the electric contact 1
This is a circuit for controlling the output of the power supply supplied to the interchangeable lens LE through 1, 19 and 17, 25. The power supply is
The power supply is controlled by transistors 6 to 8 provided on the lines of the electrical contacts 11 and 17. The power supply control circuit 4 controls the transistors 6 to 8 based on a control signal from the main microcomputer 2. A control signal for controlling ON / OFF of the terminal is output from the CL1 terminal and the CL2 terminal.

The lens attachment detection switch 5 is a switch for detecting that the interchangeable lens LE has been completely attached to the camera BD.
One terminal is connected to the CIC terminal of the power supply control circuit 4, and the other contact is grounded. This switch 5
Is off when the interchangeable lens LE is not attached,
When the interchangeable lens LE is completely mounted, it is turned on. Therefore, the main microcomputer 2 can confirm that the interchangeable lens LE is in the mounted state by inverting the P01 terminal to the low level.

Reference numeral 10 denotes a resistor for limiting the current supplied from the DC / DC converter 1 to the interchangeable lens LE. The resistor 10 protects the power supply so that an overcurrent does not flow when the electrical contact 11 is short-circuited, for example.

The transistor 6 is a bypass transistor for forming a through power supply line when supplying drive power for the interface circuit 27 and the slave microcomputer 28 to the interchangeable lens LE. The current control resistor 10 is connected between the emitter and the collector of the transistor 6, and the base is connected to the CL1 terminal of the power supply control circuit 4 via the resistor 12.

When only the interface circuit 27 is driven, it is sufficient to supply a small current limited by the current limiting resistor 10 to the interchangeable lens LE, but when the slave microcomputer 28 is driven, the current capacity is insufficient. Therefore, disconnect the resistor 10 from the power supply line,
The through state is set so that a current of a required capacity can be supplied.

The transistor 7 is a switch circuit for controlling the output of the battery voltage of the battery 3 supplied from the electric contact 17 to the interchangeable lens LE. The transistor 8 is for drawing the base current of the transistor 7, and the collector of the transistor 8 is connected to the base of the transistor 7 via the resistor 11. Therefore, when the transistor 8 is turned on, a base current flows through the transistor 7 and the transistor 7 is turned on, so that the power supply voltage of the battery 3 is directly supplied to the electric contact 17.

The base of the transistor 8 is connected to the CL2 terminal of the power supply control circuit 4 via a resistor 13, and the supply of the power is controlled by a control signal of the power supply control circuit 4.

Next, the circuit on the lens side will be described.

The interface circuit 27 includes a camera BD
Is an interface circuit interposed between the main microcomputer 2 and the slave microcomputer 28, and includes a ROM (Read Only Memory) in which information on optical characteristics, mechanical constants, and information indicating the type and function of the lens are written. I have. The interface circuit 27 sends lens-related data from the ROM to the main microcomputer 2 in response to a data communication request from the main microcomputer 2.

The interface circuit 27 has a CS terminal, a CLK1 terminal, a TxD1 terminal and an RxD1 terminal for communication with the main microcomputer 2, and via the electric contacts (12, 20) to (15, 23) respectively. Connected to the CSLNS terminal, SCK terminal, SIN terminal, and SOUT terminal of the main microcomputer 2.

The interface circuit 27 has an MR
Terminal, SE terminal, CLK2 terminal, RxD2 terminal and Tx
D2 terminals, each of which has a RE
These terminals are connected to the SET terminal, the CE terminal, the CK terminal, the DO terminal, and the DI terminal, and perform reset control of the slave microcomputer 28 and relay of data communication between the main microcomputer 2 and the slave microcomputer 28. M as described below
A reset signal is input from the R terminal to the RESET terminal of the slave microcomputer 28, and an initial reset of the slave microcomputer 28 is performed as necessary.

As will be described later, the slave microcomputer 2
8 is selected as the communication partner with the main microcomputer 2, between the CS and SE terminals, between the CLK1 and CLK2 terminals, TxD1 and RxD2 in the interface circuit 27.
And between the RxD1 and TxD2 terminals are in a through state, and the CE terminal, CK terminal, DO
Terminal and DI terminal are directly connected to the CSLN of the main microcomputer 2.
The S terminal, the SCK terminal, the SIN terminal, and the SOUT terminal are connected.

The interface circuit 27 has a VC terminal, and also controls power supply to the slave microcomputer 28. A power supply line to the slave microcomputer 28 is provided with a transistor 31 for switching power supply. The on / off control of the transistor 31 is controlled by the VC
This is performed by a control signal from the terminal. The resistance 33 is the base resistance of the transistor 31 and the resistance 34 is the transistor 3
When the VC terminal is set to a low level by one base-emitter resistance, the transistor 31 is turned on and power is supplied to the slave microcomputer 28.

The interface circuit 27 has an MV terminal so that it is possible to determine whether or not power is supplied to a drive circuit 29 of the zoom motor 30, which will be described later. The transistor 32 is a transistor for detecting whether or not the motor driving power supplied from the camera BD is in a supply state, and has a collector connected to the MV terminal of the interface circuit 27. The base of the transistor 32 is connected to the electrical contact 25 via the resistor 35. When the power is supplied to the electrical contact 25, the transistor 32 is turned on, and a low-level detection signal is supplied to the MV terminal. Is entered.

The slave microcomputer 28 is a control circuit for controlling the driving of a zoom motor 30 provided in the interchangeable lens LE described later and calculating the optical constants. The slave microcomputer 28 transfers data such as optical information and function information of the interchangeable lens LE and control information of the zoom motor to the main microcomputer 2 on the camera side, or receives data transmitted from the main microcomputer 2 and It controls driving of the zoom motor 30 and calculates optical constants.

The zoom motor 30 is a motor that drives a zoom mechanism (not shown) to change the focal length of the lens. The zoom motor 30 is connected to the slave microcomputer 2
8 is controlled by the drive circuit 29 based on the control signal from the control circuit 8.

The input terminals IN1 and IN2 of the drive circuit 29
Are terminals MC1 and MC of the slave microcomputer 28, respectively.
2 and the drive circuit 29 is connected to the terminals MC1, MC2
The zoom motor 30 is driven based on the control signal input from the controller.

Next, the operation of the camera system including the camera BD and the interchangeable lens LE will be described with reference to the timing chart of FIG.

When the interchangeable lens LE is completely mounted on the mount of the camera BD at the timing shown in the figure, the mounting detection switch 5 of the interchangeable lens LE switches from the on state to the off state, and the CIC of the power supply control circuit 4 The terminal and the P01 terminal of the main microcomputer 2 are inverted from “L” to “H”, respectively.

The power supply control circuit 4 has input terminals CIA,
Output terminals CL1 and C according to the input state of CIB and CIC
This is a logic circuit that determines the output state of L2, and has a logic as shown in Table 1. Since the output from the CIC terminal is not used as a control signal, it is omitted in the following description of the control.

[0047]

[Table 1]

In the state [A] in Table 1, "L" is input to the CIC terminal, that is, the interchangeable lens LE is not completely mounted on the mount of the camera BD, and the mounting detection switch 5 is turned on. Is in the state. At this time, the terminals CL1 and CL2 become "H" and "L", respectively, as shown in Table 1, and all the transistors 6 to 8 are turned off, so that power is not supplied to the electrical contact 17. Also, a small amount of power limited by the resistor 10 is supplied to the electric contact 11.

Until the timing shown in FIG. 2, the state of [A] in Table 1 is established, and the terminals 11 and 17 related to the power supply exposed from the camera BD come into contact with an external metal or the like and are grounded. It is short-circuited to 12 and 16, so that an abnormally large current flows and abnormal operation does not occur, and electric circuit components in the camera BD are not destroyed.

When the interchangeable lens LE is completely mounted on the mount of the camera BD at the timing described above, the minute electric power limited by the resistor 10 to the interface circuit 27 on the interchangeable lens LE side via the electrical contacts 11 and 19 is output. Power is supplied. Note that this small amount of power has a power value sufficient for the interface circuit 27 to operate.

When the power is supplied to the interface circuit 27, a power-on reset is performed and the interface circuit 27 starts operating in an initial state. In this initial state, “H” is output to the VC terminal, the transistor 31 is off, and power is not supplied to the slave microcomputer 28. Also, terminals MR, SE, connected to the slave microcomputer 28 of the interface circuit 27.
“L” is output to CLK2, RxD2, and TxD2.

Next, when the main microcomputer 2 on the camera BD detects a change in the PO1 terminal from "L" to "H" from the state of the timing, the output terminal VC1 is changed from "L" to "H" at the timing. ". The output terminal V
C2 is held in the “L” state.

The power supply control circuit 4 is in the state of [B] in Table 1 between the timings from the timing of the above, and all the transistors 6 to 8 are kept in the off state.
At the timing shown in FIG. At this time, the CL1 and CL2 terminals of the power supply control circuit 4 become "L" and "H", whereby the transistors 6 to
8 are all switched on. Thereby, the electric contact 11
Is supplied with power sufficient to operate all the electric circuits on the interchangeable lens LE side. In addition, the electric contact 17 has
The battery voltage of the battery 3 is supplied.

Next, at the following timing, the main microcomputer 2
Is CSLN for communicating with the circuit on the interchangeable lens LE side.
An "L" chip select signal is output to the S terminal, a synchronous clock for data transmission and reception is output to the SCK terminal, and the R clock in the interface circuit 27 of the interchangeable lens LE is output.
The data regarding the lens is read from the OM. The data includes information indicating the function and type of the interchangeable lens LE and data indicating whether or not the interchangeable lens LE has the slave microcomputer 28. In this data reading, no data is output from the SOUT terminal of the main microcomputer 2 and the data is held at the “L” level.

The data is composed of 8 bits as shown in FIG. 7, and the synchronous clock is also divided for every eight pulse trains. Here, data is output at the rising edge of the synchronous clock, and data is taken into each circuit at the falling edge.

Returning to FIG. 2, the main microcomputer 2 outputs a predetermined number (N bytes) of clocks and fetches data transferred from the ROM in the interface circuit 27 via the electrical contacts 14. In CSLN
The chip select signal of "H" is output to the S terminal to end the communication.

After the end of the communication, the main microcomputer 2 converts the interchangeable lens LE from the read data into the slave microcomputer 28.
Is determined. In this camera system, since the interchangeable lens LE includes a microcomputer, it is determined that the microcomputer is present. The main microcomputer 2 enters a sequence for starting the slave microcomputer 28 on the interchangeable lens LE side based on the determination result.

The timing of (1) is the start timing of the sequence for activating the slave microcomputer 28.
The main microcomputer 2 outputs “H” to the SCK terminal at the following timing, and then inverts the CSLNS terminal to “L” after a predetermined time delay.

It should be noted that, except during data communication, "L" is normally output to the SCK terminal and "H" is normally output to the CSLNS terminal as shown in the figure.

Subsequently, the main microcomputer 2 inverts the SCK terminal to "L" at the timing of, and inverts the CSLNS terminal to "H" at further timing. this~
The signal sent from the main microcomputer 2 to the interface circuit 27 at the timing of (1) is a communication control signal for activating the slave microcomputer 28 and switching the communication partner from the interface circuit 27 to the slave microcomputer 28.

Next, the operation of the interface circuit 27 having received the communication control signal will be described.

Table 2 shows the M of the interface circuit 27.
It shows the signal output relationship between the V, CS and CLK terminals and the VC and MR terminals.

[0063]

[Table 2]

As shown in Table 2, when the CS terminal changes from "H" to "L" while the CLK terminal is "L" (states [a] and [c]), the VC terminal and the MR terminal The output does not change. Since this is a state at the time of starting the communication between the normal camera BD and the interchangeable lens LE, the VC terminal and the M
The change of the output of the R terminal is prohibited.

On the other hand, when the CS terminal changes from “H” to “L” while the CLK terminal is “H”, ([b],
In the state [d]), an “H” signal is output to the VC terminal, and an “L” signal is output to the MR terminal. Of these, the state [d] is a preparation stage for operating the slave microcomputer 28. When the CLK terminal falls from “H” to “L” from the state of [d] (timing in FIG. 2), V
An “L” signal is output to the C terminal, the transistor 31 is turned on, and power is supplied to the slave microcomputer 28. The MR terminal is held at the "L" output, and the slave microcomputer 28 is held in the reset state.

Thereafter, when the CS terminal of the interface circuit 27 rises from "L" to "H" (timing in FIG. 2), the MR terminal is inverted to "H" and the reset state of the slave microcomputer 28 is released. Then, the slave microcomputer 28 starts up according to the internal program. At this time, the RxD2 terminal of the interface circuit 27 changes from the "L" output to the input state, and the TxD2 terminal changes from the "L" output to the high impedance state.

That is, the above operation is performed by determining whether or not power is supplied from the camera BD side via the electrical contact 17 in the interface circuit 27 to determine whether the type of the camera BD is a camera for a new system. If the type of camera BD is a camera for a new system, the slave microcomputer 28 is activated based on a communication control signal input from the camera BD, and the slave microcomputer 2 The setting is switched to the other party.

The state of [b] in Table 2 indicates the state of the VC terminal,
The output of the MR terminal is the same as the state of [d], but the MV terminal is in the “H” state and no power is supplied to the interchangeable lens LE side. Therefore, in this case,
Since the slave microcomputer 2 cannot be started,
Even when the communication control signal is input from the camera BD, the VC terminal and the MR terminal are held in the “H” state and the “L” state, respectively, and the initial reset state of the interface circuit 27 is held.

The above operation is performed by the camera BD and the interchangeable lens L
The main microcomputer 2 of the camera BD resets the circuit of the interchangeable lens LE as needed when the abnormality of the operation of the electric circuit of E is detected.

Returning to FIG. 2, when the slave microcomputer 28 is started at the timing shown in FIG. 2, the input / output ports and the internal RAM are first initialized, and a state of waiting for communication with the camera BD is established.

The main microcomputer 2 on the camera BD side starts data communication with the slave microcomputer 28 at a timing after a predetermined time required for the slave microcomputer 28 to perform the initialization has elapsed from the timing. I do. The basic operation of this data communication is to read data related to the lens from the above-described interface circuit 27 (communication between the timings after).
In this case, the difference is that bidirectional communication is performed between the main microcomputer 2 and the slave microcomputer 28. When the slave microcomputer 28 is operating, the CLK1 terminal of the interface circuit 27 is connected to the C1 terminal.
The LK2 terminal, the TxD1 terminal and the RxD2 terminal, the RxD1 terminal and the TxD2 terminal, and the CS terminal and the SE terminal are in a through state, and the microcomputers 2 and 28 can directly communicate data.

The main microcomputer 2 inputs the "L" chip select signal to the CE terminal of the slave microcomputer 28 at the timing of (1) to notify the start of data communication. The slave microcomputer 28 detects "L" input to the CE terminal and prepares for data communication.

Subsequently, the main microcomputer 2 outputs a synchronous clock from the SCK terminal and outputs data from the SOUT terminal to the DI terminal of the slave microcomputer 28. On the other hand, the slave microcomputer 28 is
While the data transmitted from the MIC terminal is taken in, the data is output from the DO terminal to the SIN terminal of the main microcomputer 2 in synchronization with the synchronous clock input to the CK terminal. This bidirectional data communication is also performed at the timing shown in FIG.

The first data (first byte data Dc1) sent from the main microcomputer 2 to the slave microcomputer 28 is data representing the type of the camera BD and the like. The data Dc2 of the second byte is an interchangeable lens LE.
This is information for designating a command to be output and data to be output. On the other hand, from the slave microcomputer 28 to the main microcomputer 2
The first data Db1 to be transferred to the storage device is dummy data, and the second byte of data Db2 is data representing the type of the interchangeable lens LE.

After the main microcomputer 2 receives Db2,
The type of the interchangeable lens LE is determined, and thereafter, data such as an instruction corresponding to the type of the interchangeable lens LE is transmitted. on the other hand,
The slave microcomputer 28 controls the camera BD based on the data Dc1.
Of the main microcomputer 2 based on the data Dc2.
Determine what data is needed. Then, based on the result of this determination, the slave microcomputer 28 outputs data required by the main microcomputer 2 as data after the data Dc3.

Subsequently, when the data communication is completed, the main microcomputer 2 sends an "H" chip select signal to the slave microcomputer 28 at the timing of notifying the end of the data communication. Thereafter, the main microcomputer 2 on the camera BD side performs data communication with the slave microcomputer 28 periodically or as necessary.

The slave microcomputer 28 on the interchangeable lens LE side
Drives the zoom motor 30 in the interchangeable lens LE via the drive circuit 29 based on the command data received from the main microcomputer 2. Motor drive control signals are output from the Mc1 and Mc2 terminals of the slave microcomputer 28 to the drive circuit 29, and control such as normal rotation, reversal, braking, and stop of the zoom motor 30 is performed by a combination of these two control signals.

Next, a case where an interchangeable lens LE without a conventional microcomputer is mounted on the camera BD according to the present invention will be described.

FIG. 3 is a system configuration diagram of a camera system in which a conventional interchangeable lens LE without a microcomputer is mounted on a camera BD according to the present invention. In the figure,
The circuit configuration on the camera BD side is the same as that shown in FIG. On the other hand, the interchangeable lens LE 'has an internal ROM and an interface circuit 27' having only a function of transmitting data on the lens from the internal ROM to the camera BD. Therefore, the interface circuit 27 'includes a power supply terminal VDD, a chip select signal terminal CS, a synchronous clock terminal CLK, a data transmission terminal TxD1, and a G terminal.
It has only the ND terminal.

The interchangeable lens LE 'is provided with electric contacts 19 to 22, 24 according to the configuration of the interface circuit 27'.
Have only Therefore, the electric contact 1 of the camera BD
5, 17, and 18 are not connected.

FIG. 4 is a time chart for explaining the operation of the camera system. In the figure, the operation up to the timing 'is the same as the operation up to the timing in FIG. When the reading of the data on the lens is completed at the timing of ', the main microcomputer 2 determines whether or not the interchangeable lens LE' has the slave microcomputer 28 from the data on this lens. In this camera system, the interchangeable lens LE '
Does not have a slave microcomputer, the main microcomputer 2 transmits a communication control signal (a control signal for activating the slave microcomputer and switching the communication partner to the slave microcomputer) at the timings (1) to (4) in FIG. In the subsequent operation without transmitting the data to the interface circuit 2 periodically or as necessary.
Only the operation of reading the data on the lens from the ROM in 7 'is performed. Therefore, at the timings' to 'in FIG. 4, data on the lens is read from the ROM in the interface circuit 27'.

As described above, the camera BD identifies the type of the interchangeable lens from the data on the lens even when the interchangeable lens LE 'having no conventional slave microcomputer 28 is mounted, and is compatible with the interchangeable lens. Since data communication is performed by transmitting a control signal, a camera system can be configured even with the interchangeable lens of the old system.

Next, a case where the interchangeable lens LE according to the present invention is mounted on a conventional camera BD 'will be described.

FIG. 5 is a system configuration diagram of a camera system in which the interchangeable lens LE according to the present invention is mounted on a conventional camera BD '. In the figure, the circuit configuration on the interchangeable lens LE side is the same as that shown in FIG. On the other hand, camera B
D ′ has only a main microcomputer 2 ′ that reads data related to the lens from the interchangeable lens LE side and controls a photographing operation, and supplies a large-capacity power supply for driving the zoom motor 30 on the interchangeable lens LE side. The contact 17 is not provided. Further, there is no switching function for switching the capacity of the power supplied from the electric contact 11 to the interchangeable lens LE side, and therefore, the power supply control circuit 4 and the transistors 6 to 8 for controlling the power supply are not provided.

In this camera system, since the drive power for the drive circuit 29 is not supplied from the camera BD side, the transistor 32 is always off and the MV terminal of the interface circuit 27 is also in the "H" state. For this reason, after the interchangeable lens LE is mounted on the camera BD 'and the power-on reset of the interface circuit 27 is started, the VC terminal of the interface circuit 27 is held in the "H" state, and the MR terminal is held in the "L" state. The slave microcomputer 28 is not supplied with power, and is not started by the reset signal.

Therefore, the interface circuit 27 supplies the internal RO to the camera BD in response to a request from the main microcomputer 2 '.
Only the operation of transmitting the data relating to the lens stored in M is performed.

FIG. 6 is a time chart for explaining the operation of the present camera system. As shown in the figure, in the present camera system, the main microcomputer 2 'periodically performs an operation of reading data relating to the lens from the interface circuit 27 of the interchangeable lens LE.

Although the camera BD 'does not include the switch 5 for detecting the attachment of the interchangeable lens LE, the camera BD'
Since the data regarding the lens cannot be read out from the interface circuit 27 while the lens is not completely mounted, the main microcomputer 2 'thereby operates the interchangeable lens L
The mounting state of E is detected.

Therefore, when the interchangeable lens LE is mounted on the camera BD ', the main microcomputer 2'
From the ROM of the interface circuit 27 to the data Da1 to lens
Dak is read. The data Da1 to Dak include information that the interchangeable lens LE is equipped with a microcomputer, but the main microcomputer 2 'does not have a function corresponding to the data contents. Information is ignored.

In this camera system, the power zoom function of the interchangeable lens LE cannot be operated as in the new camera system, but it is possible to read the lens data necessary for controlling the photographing of the main microcomputer 2 'of the camera BD'. Thus, it is possible to fulfill the function of the conventional camera system.

[0091]

As described above, according to the present invention, the camera is provided with a large-capacity power supply output means for the lens driving means and a small-capacity power supply output means for the drive control means for controlling the driving of the driving means. Provided, it is determined from the data regarding the lens read from the mounted interchangeable lens that the interchangeable lens has a lens drive mechanism by which the lens is driven by the drive unit based on the control of the drive control unit, Since a predetermined communication control signal is output to the interchangeable lens in order to enable data communication with the drive control means, the camera can control reading of only data related to the lens for an interchangeable lens not having the lens driving mechanism. It becomes possible to control the driving of the zoom lens for the interchangeable lens having the lens driving mechanism by communicating with the driving control means. Becomes ability, it is possible to construct a camera system in combination with any of the interchangeable lens regardless functions of the interchangeable lens.

Further, a lens driving means driven by a power supplied from the camera side to the interchangeable lens and a drive control means for controlling the driving of the driving means are provided, and the power of the driving means is supplied from the camera side. When a predetermined communication control signal is input in a state in which the camera is in the state, the data communication partner with the camera side is switched to the drive control means, so that
Even when the interchangeable lens is mounted on a camera that does not have a function of supplying power to the driving unit, a communication partner of data in the interchangeable lens is suitably set according to the control function of the camera,
A camera system can be configured in combination with an arbitrary camera regardless of the control function of the camera.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration diagram of a camera system in which a camera according to the present invention and an interchangeable lens are combined.

FIG. 2 is a time chart for explaining the operation of the camera system.

FIG. 3 is a diagram showing a system configuration diagram of a second camera system in which a camera according to the present invention and a conventional interchangeable lens are combined.

FIG. 4 is a time chart for explaining the operation of the second camera system.

FIG. 5 is a diagram showing a system configuration diagram of a third camera system in which the interchangeable lens according to the present invention and a conventional camera are combined.

FIG. 6 is a time chart for explaining the operation of the third camera system.

FIG. 7 is a diagram showing a configuration of data to be exchanged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC / DC converter 2 Main microcomputer 3 Battery 4 Power supply control circuit 5 Lens attachment detection switch 6-8,31,32 Transistor 10-13,33-35 Resistance 11-26 Electrical contact 27 Interface circuit 28 Slave microcomputer (drive control Means) 29 drive circuit (drive means) 30 zoom motor

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-187333 (JP, A) JP-A-3-72308 (JP, A) JP-A-61-165743 (JP, A) 252639 (JP, A) JP-A-58-59432 (JP, A) JP-A-1-221728 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 7/02-7 / 105 G03B 17/04-17/17 G02B 7/28-7/40 G03B 3/00-3/12

Claims (2)

(57) [Claims] 1. A camera in which an interchangeable lens having a memory in which information on a lens is readablely stored is mounted, a power supply means, and a first power supply for supplying a small amount of power to the interchangeable lens. Output means, second power supply output means for supplying a large amount of power to the interchangeable lens side, data input / output means for inputting / outputting data between the interchangeable lenses, and information on the read lens A driving means for driving the interchangeable lens with the large-capacity power supply and a driving control means for driving with the small-capacity power supply, wherein the lens is driven by the driving means based on the control of the driving control means Communication with the drive control means when it is determined that the interchangeable lens has the lens drive mechanism. And a control signal output means for outputting a predetermined communication control signal to the interchangeable lens. 2. An interchangeable lens of a camera having a memory in which information on a lens is readablely stored and in which information on the lens is read out to the camera side by data communication with a mounted camera. A driving unit, a driving control unit for controlling the driving of the driving unit, a first power input unit for inputting a power supplied from the camera to the driving unit, and a power supplied from the camera. Second input to drive control means
Power input means, data input / output means for inputting / outputting data between the cameras, a determination means for determining whether or not power is supplied from the camera to the drive means, and a power supply to the drive means. When it is determined that power is supplied and a predetermined communication control signal is input from the camera side, the power input from the second power input means is supplied to the drive control means, and communication with the camera is performed. A communication control means for switching and setting the other party to the drive control means.