JPH06324387A - Accessory converter for power source of camera - Google Patents

Abstract

PURPOSE:To provide a converter which can use an accessory even when a voltage used by the electronic circuit of a lens attached so that it can be attached to and detached from a camera main body is different from a voltage used by the camera main body. CONSTITUTION:This is the converter which is loaded on an interval with the interchangeable lens provided with the electronic circuits 28 and 28 actuated by the power source 1 of the camera main body and which converts the power source voltage of the camera main body to the voltage used in the electronic circuits of the accessory. The attaching part attached so that it can be attached to and detached from a connection part between the camera main body and the accessory is provided with terminals 16-27 in contact with the camera main body and the electric signal terminal of the accessory. Besides, a DC/DC converter is provided between the terminals 16, 17 and 21 in contact with terminals for a power source on the camera main body side and the terminals 22, 23 and 27 in contact with terminals for feeding power on the accessory side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accessory converter for a power supply of a camera, and more specifically, the operating voltage of an accessory having an electric device such as a lens or strobe that is detachably attached to the camera body is equal to The present invention relates to a converter that converts a power supply voltage of a camera body into a working voltage of an accessory when different.

[0002]

2. Description of the Related Art Conventionally, many interchangeable lenses such as autofocus cameras have an electronic circuit in order to store the unique information of the lens and to control the drive of the focus lens. Although some of these electronic circuits operate by having a battery in the lens, they are generally operated by being supplied with power from the battery of the camera body.

[0003]

However, in the above conventional example, a constant power supply voltage must be supplied to the interchangeable lens. Therefore, when the power supply voltage required by the camera body is different from the power supply voltage supplied to the lens, it is necessary to have a plurality of power supply voltages.

Further, in order to lower the voltage of semiconductors and reduce power consumption in recent years, it is necessary to lower the power supply voltage of the entire camera system such as the camera and interchangeable lens. There was a drawback that the lens of was not usable.

[0005]

However, according to the present invention, when a conventional lens operating at a high voltage is attached to a camera operating at a low voltage, an adapter is provided between the camera and the lens. By connecting a power supply voltage conversion means such as a DC / DC converter for converting the power supply voltage to the adapter and converting the power supply voltage, compatibility with accessories such as cameras and lenses that require different power supply voltages You can keep your sex.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a camera system embodying the present invention, in which 1 is a battery which is a power source, 2 is a main switch for turning on the power source, 3 is the voltage of the battery 1 and the circuit of the camera is DC / DC converter that converts to the required voltage, 4 is a microcomputer that controls the entire camera,
Reference numeral 5 is a control circuit for controlling the film feeding motor and shutter of the camera body, 6 is a film feeding motor,
7 is a first magnet for controlling the shutter, 8 is a second magnet for controlling the shutter, 9 is a battery power supply terminal for sending power from a battery to the lens, and 10 is a stable electric circuit of the lens. For supplying the converted power,
A stabilized power supply terminal, 11 is a clock terminal that outputs a clock for communication between the microcomputer 4 of the camera body and the lens microcomputer 28, and 12 is communication between the microcomputer 4 of the camera body and the lens microcomputer 28. Is a data output terminal for sending data from the camera body to the lens, 13 is a data input terminal for sending data for communication between the camera microcomputer 4 and the lens microcomputer 28 from the lens to the camera body, and 14 is a power source and This is the ground terminal for communication. The above is provided on the camera body.

Reference numeral 15 is a DC / DC converter for converting voltage, 16 is a battery power supply terminal for receiving power from the battery 1, 17 is a stabilized power supply terminal for supplying stabilized power, and 18 is A clock terminal for receiving a clock for communication between the microcomputer 4 of the camera main body and the microcomputer 28 of the lens, and 19 is data for communication between the microcomputer 4 of the camera main body and the lens microcomputer 28 from the camera main body. A data input terminal for receiving data from the lens, a data output terminal for sending data for communication between the microcomputer 4 of the camera body and the microcomputer 28 of the lens from the lens to the camera body, 21 a ground terminal for power supply and communication, and 22 a lens Battery power terminal for sending power from the battery to the Stabilized power supply terminal to issue a voltage converted by the DC / DC converter 15 to supply power stabilized to the electric circuit of the lens, 24 is a microcomputer 2 of the microcomputer 4 and the lens of the camera body
A clock terminal that outputs a clock for communication by 8 and 2
Reference numeral 5 is a data output terminal for sending data for communication between the macro computer 4 of the camera body and the microcomputer 28 of the lens from the camera body to the lens, and 26 is communication between the microcomputer 4 of the camera body and the lens microcomputer 28. Is a data input terminal for sending data from the lens to the camera body, 27 is a power supply or communication ground terminal, and the above is provided in the lens converter.

Reference numeral 28 denotes a lens control microcomputer for storing information peculiar to the lens and for performing focus drive control and aperture drive control of the lens, which is operated by a power supply of 5V. Reference numeral 29 denotes a lens control circuit for controlling the focus drive motor and the aperture drive motor of the lens, which requires a stable power supply of 5V and a power supply of 2V to 6V for driving the motor. 30 is a focus drive motor for driving the focus lens, 31 is a diaphragm drive motor for driving the diaphragm, 32 is a battery power supply terminal for receiving power from the battery 1 for driving the motor, and 33 is a lens A stabilized power supply terminal for receiving a stabilized power supply for operating the electronic circuit, 34 is a clock terminal for receiving a clock for the microcomputer 4 of the camera body and the microcomputer 28 of the lens to communicate, and 35 is A data input terminal that receives data for communication between the macro computer 4 of the camera body and the microcomputer 28 of the lens from the camera body to the lens, and 36 is used for communication between the microcomputer 4 of the camera body and the lens microcomputer 28. Data output that sends data from the lens to the camera body Child, 37 of ground terminal of the power supply or communication, or is provided in the lens converter.

The operation of this embodiment having the above-mentioned structure will be described.

First, when the power switch 2 is turned on, DC
Power is supplied to the / DC converter 3, and the DC / DC converter 3 starts operating. The input of the DC / DC converter 3 is supplied from the battery 1 of the power source, and the open voltage of the battery is about 3V, but when the load such as the film feeding motor operates, the output voltage drops to about 1V. Therefore, it changes from about 1V to about 3V. Also,
Since the output serves as a power source for the microcomputer 4 and the control circuit, it outputs a stable output voltage of 3V. At this time, the output voltage of the battery is supplied to the battery power supply terminal 9 for sending the power from the battery 1 to the lens, and the stabilized voltage of the DC / DC converter 3 is supplied to the stabilized power supply terminal 10. 3V is output.

When power is supplied from the DC / DC converter 3, the microcomputer 4 starts its operation according to a predetermined program. The microcomputer 4 controls the control circuit 5 by a communication line, and the lens communication terminals 34, 35 from the lens communication terminals 11, 12, 13 through the lens converter communication terminals 18, 19, 20 and 24, 25, 26. , 36 and the lens connected to the microcomputer 28 connected to the lens, and the fact that the lens is properly attached is detected by the communication being possible.

After confirming that the lens is mounted, the microcomputer 4 reads out the unique information of the lens stored in the microcomputer 28 of the lens and uses it for the autofocus calculation and control and the determination of the exposure value. Further, when a release switch (not shown) is turned on to turn on the microcomputer 4, the distance measuring circuit (not shown) performs distance measurement for autofocus to calculate a lens drive amount, and communicates with the lens microcomputer 28 by communication. The lens drive amount is sent, the lens is moved to the in-focus position, and the distance measuring circuit again confirms that the lens is in the in-focus position. After that, in order to perform exposure control, the diaphragm drive amount is sent to the microcomputer 28 of the lens by communication, and after the diaphragm control, the first magnet 7 for shutter control is controlled through the control circuit 5 to open the shutter,
Second magnet 8 for shutter control after a lapse of a predetermined time
The shutter is closed through the control circuit 5 and the exposure control is completed.

When the exposure control is completed, the film feeding motor 6 is controlled through the control circuit 5 in order to wind the film, and a predetermined amount of film is fed to complete a series of release operations. At this time, the control circuit 5 is supplied with the power directly supplied from the battery 1 and the power supplied from the DC / DC converter 3, but the power supplied from the DC / DC converter 3 is for operating the control circuit. The power supplied directly from the battery is for driving the film feeding motor 6 and the shutter control magnets 7, 8.

Next, the operation of the lens converter will be described.

The power supplied to the battery power supply terminal 16 of the lens converter is supplied as it is to the battery power supply terminal 22 to the lens, and the DC in the lens converter is also supplied.
It is supplied to the / DC converter 15 through the VBAT terminal. Further, stabilized power from the DC / DC converter 3 of the camera body is supplied from the stabilized power supply terminal 17, and C of the DC / DC converter 15 of the lens converter is supplied.
It is input to the TRL terminal.

Next, the operation of the DC / DC converter 15 in the lens converter will be described with reference to FIG. FIG. 2 shows the inside of the DC / DC converter 15 of the lens converter shown in FIG. 1, 38 is an NPN transistor for switching according to the input of the CTRL terminal, 39
Is VB according to the switching of the NPN transistor 38.
A PNP transistor for switching the power supply from the AT terminal, 40 is a voltage from the battery 1 input from the VBAT terminal through the PNP transistor 39, here a stable voltage of 5V from an input voltage varying from about 1V to 3V. It is a DC / DC converter main body for converting into. When the power switch 2 of the camera body is turned on with the lens converter attached to the camera, power is supplied from the battery to the VBAT terminal. In addition, D of the camera body
When the C / DC converter 3 starts operating and power is supplied to the CTRL terminal, the NPN transistor 38 is turned on and the PNP transistor 39 is turned on.
As a result, power is supplied from the battery 1 to the DC / DC converter main body 40, and the DC / DC converter 40 receives 5V.
The stabilized voltage of is output to OUT.

From here, the description will be made returning to FIG. VBAT of DC / DC converter 15 in the lens converter
When the power from the battery 1 is supplied to the terminal and the stabilized power is supplied from the camera body to the CTRL terminal, DC / D
Since the C converter 15 outputs a stabilized voltage of 5V to the OUT terminal, a voltage of 5V is output to the stabilized power supply output terminal 23 of the lens converter. Further, the lens communication terminals 18, 19, 20 and 24, 25, 26 are connected to each other, and a communication signal is directly transmitted from the camera body to the lens or from the lens to the camera body.

Next, the operation of the lens will be described. The operating voltage of the control system of the lens shown in FIG. 1 operates at 5V.
When the lens converter and the lens are mounted on the camera body and the power switch 2 of the camera body is turned on, power is supplied to the power supply terminal 32 and the stabilized power supply terminal 33 from the battery 1. As a result, 5V power is supplied to the lens control microcomputer 28 and the VDD terminal of the lens control circuit 29, and the lens control circuit 29 VB
Power is supplied from the battery 1 to the AT terminal. When 5V power is supplied to VDD of the lens control microcomputer 28, the microcomputer 28 starts operating and communicates from the camera body through the communication terminals 34, 35, 36 to obtain lens data such as lens specific information. To the camera body. When a focus or aperture drive command is further received from the camera body, the lens control circuit 29 is controlled to control the focus drive motor 30 or the aperture drive motor 31 to move the focus lens to the in-focus position or set the aperture to a predetermined value. The aperture value is narrowed down or opened. At this time, the focus drive motor 30 and the aperture drive motor 31 are powered by the VBAT through the lens control circuit 29.
The focus drive motor 30 and the diaphragm drive motor 31 are designed to operate from a power supply voltage of 2V to 6V, and are driven by the power supply from the battery 1 supplied to the terminals. The camera body shown in FIG.

Next, a case where a lens operating at 3V is directly adhered to the camera body shown in FIG. 1 will be described with reference to FIG. Since the camera shown here is the same as the camera shown in FIG. 1, description thereof will be omitted. Next, the lens will be described.
Reference numeral 51 denotes a lens control microcomputer that stores information unique to the lens and performs focus drive control and aperture drive control of the lens, which requires a 3V power supply. Reference numeral 52 is a lens control circuit for controlling the focus drive motor and diaphragm drive motor of the lens, and 53 is a focus drive motor for driving the focus lens, which requires a stable power supply of 3V and a power supply of 2V to 3V. 54 is a diaphragm drive motor for driving the diaphragm, 55 is a battery power supply terminal for receiving power supply from a battery for driving the motor,
56 is a stabilized power supply terminal for receiving a stabilized power supply for operating the electronic circuit of the lens, 57 is a clock terminal for receiving a clock for communication between the microcomputer of the camera and the microcomputer of the lens, 58 Is a data input terminal for receiving data for communication between the camera microcomputer and the lens microcomputer from the camera to the lens, and 59 is data for communicating between the camera microcomputer and the lens microcomputer from the lens to the camera. A data output terminal for sending, 60 is a ground terminal for power supply and communication.

With such a structure, the power switch 2 of the camera
When is turned on, the lens control microcomputer 51
A stable power supply of 3V is supplied to and the operation starts. The subsequent operation is exactly the same as that shown in FIG. 1 except that the power supply voltage is different, and only the camera and the lens operate.

As described above, when bonding a lens operating at 5V to a camera operating at 3V, it is necessary to attach a 5V lens for the lens.
A lens converter with a built-in DC / DC converter for supplying a stable power supply of V is used to supply a 5V power supply to the electric circuit of the lens, thereby mounting a lens having a different power supply voltage on a camera having a different power supply voltage. can do. Also, lenses with the same power supply voltage can be attached to the camera without a converter.

Further, in this embodiment, the DC / DC converter of the lens converter is a system for converting the input voltage from the battery into 5V, but the same applies even when the voltage of 3V output from the DC / DC converter of the camera is used as the power source. Is.

In this embodiment, the case where the lens operating on the 5V power supply is attached to the camera operating on the 3V power supply has been described.
The same applies when mounting a lens that operates in the V system using a converter, by changing the power supply voltage in the lens converter, and when mounting a lens that operates at a power supply voltage different from that of a camera that operates at another power supply voltage. Is also the same.

Although the lens has been described in this embodiment, it is possible to use an accessory having a different power supply voltage by converting the power supply voltage in the converter when using another accessory such as a strobe. it can.

[0025]

As described above, according to the present invention,
When attaching a lens to a camera that operates at a low voltage, such as a conventional lens that operates at a high voltage with a different power supply voltage, connect the adapter between the camera and the lens and convert the power supply voltage inside the adapter. By converting the power supply voltage with a power supply voltage converter such as a DC / DC converter, it is possible to maintain compatibility with cameras and accessories such as lenses that require different power supply voltages.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a DC / DC converter in the converter of FIG.

FIG. 3 is a diagram showing a conventional camera system.

[Explanation of symbols]

1 ... Battery 2 ... Main switch 3 ... DC / DC converter 4 ... Microcomputer 6 ... Film feeding motor 15 ... DC / DC
Converter 28 ... Microcomputer 29 ... Lens control circuit 30 ... Focus drive motor 31 ... Aperture drive motor 40 ... DC / DC converter 51 ... Microcomputer 52 ... Lens control circuit 53 ... Focus drive motor 54 ... Aperture drive motor

Claims (1)

[Claims] 1. A camera main body and an accessory such as an interchangeable lens having an electric device that operates by receiving the power supply of the camera main body, and is mounted between the camera main body and a power supply voltage of the accessory. An accessory converter for a power supply of a camera, which converts into a working voltage, wherein an attachment portion detachably attached to a connection portion between the camera body and the accessory contacts an electric signal terminal of the camera body and the accessory. A power supply for a camera, characterized in that each has a terminal, and a voltage converter is provided between the terminal in contact with the power supply terminal on the camera body side and the terminal in contact with the power supply terminal on the accessory side. Accessory converter.