JP2984394B2 - converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter for connecting a lens barrel of a different type to a camera body.

[0002]

2. Description of the Related Art In recent years, with the development of actuators, sensors, electronic circuits, and the like, autofocus and automatic exposure control have become mainstream for both video cameras and still cameras.

In single-lens reflex still cameras, there are known interchangeable lenses that mechanically control the aperture and drive a focusing lens from the camera body as shown in JP-B-63-67171 and JP-B-63-67172. .

On the other hand, as a diaphragm and lens drive system of a lens interchangeable single-lens reflex camera, there is proposed a system adopting a system in which a mechanical connection between a camera body and a lens barrel is eliminated and a lens and a diaphragm are driven only by electrical connection. The applicant has already filed an application (for example, Japanese Patent Publication No. 1-17139). Since this system employs a dedicated actuator for each lens, there are many advantages such as focusing speed, accuracy, and silencing.

Further, with the spread of small-sized video cameras, the need for video cameras with interchangeable lenses is increasing. In a video camera with interchangeable lenses, a system having only the latter electrical connection and having a dedicated actuator for each lens is desirable.

[0006]

However, a lens for a system in which a camera and a lens are mechanically linked to each other is used (diverted) for a camera in a system in which the camera and the lens are only electrically connected. Is convenient for users, but not realized.

[0007]

SUMMARY OF THE INVENTION The present invention provides a first type of camera system which drives a focusing lens moving mechanism and a diaphragm device in a lens barrel by using an actuator provided in the lens barrel. It is mounted between a camera body used and a lens barrel used in a second type of camera system that mechanically drives a focusing lens moving mechanism and an aperture device in the lens barrel from the camera body. A camera body of the first type and the second body.
Communication means for communicating with the lens barrel of the type;
A driving mechanism including an actuator for mechanically driving a focusing lens moving mechanism in a lens barrel of the second type and an aperture device, wherein the communication unit is a camera body of the first type. Control circuit in the camera and the second
A control circuit in the converter that communicates with the memory means in the lens barrel of the type, wherein the control circuit in the converter reads lens information such as the focal length from the memory means, and changes by the presence of the converter. And at the same time, convert the information into information suitable for the camera body of the first type and supply it to the control circuit in the camera,
A converter is used for receiving the focusing control information and the aperture control information from the in-camera control circuit and controlling the driving mechanism.

[0008]

FIG. 1 is a sectional view of a converter as an embodiment, FIG. 2 is a perspective view, and FIG. 3 is a configuration diagram of a camera system with the converter mounted. Reference numeral 1 denotes a first bayonet mount having a claw portion 1a that can be mounted on a mount of a video camera 23 described later, and is fixed to the main body 3 by screws 2. Reference numeral 3a denotes a second bayonet mount that can be mounted on a mount of a lens barrel 21 described later. 4
Is a fixed portion inside where a plurality of contacts 5 are insert-molded. Reference numeral 5 denotes a contact which comes into contact with the contact 27a on the video camera side at the time of mounting. 6 is a focusing lens I in the lens barrel 21
, Which is supported so as to be movable in the optical axis direction and is retractable. The interlocking shaft 6 is urged by a spring 7 in the protruding direction. 8, 9 are transmission gears, 1
Reference numeral 0 denotes an AF motor, and the rotation of the output gear 10a is transmitted to the interlocking shaft 6 via the transmission gears 8 and 9. Reference numeral 11 is interlocked with the aperture motor 12, and can be connected to the aperture interlocking member 24 of the lens barrel by the transmission member 11a. 13a, 1
Reference numeral 3b denotes a circuit board, and reference numerals 14a and 14b denote control of the motors 10 and 12, and cpu2 which converts lens-specific information written in the cpu 25 in the lens so that it can be communicated to the video camera.
6 is a group of circuit chips including the number 6. Reference numeral 15 denotes a contact that comes into contact with the contact 25a of the lens barrel at the time of mounting.

In FIG. 3, reference numeral 21 denotes a lens barrel as an interchangeable lens.
Is driven to open and close by the mechanical movement of the aperture interlocking member 24 around the optical axis based on the movement of the transmission member 11a in the converter 22. Reference numeral 32 denotes a connection shaft connected to the interlocking shaft 6 in the converter 22, and reference numeral 33 denotes a gear rotated by rotation of the connection shaft 32, and a gear portion 34 of the holding lens barrel portion 34 for a focusing lens.
a. Reference numeral 25 denotes an in-lens cpu, which stores lens-specific information (for example, focal length, aperture control range, and the like) and serves to communicate with the video camera 23 side. Reference numeral 25a denotes a contact that contacts the contact 27a of the video camera or the contact 15 of the converter 22, and connects the respective cpu communicablely.

Reference numeral 23 denotes a video camera. 28 is a CCD
In addition to receiving the subject light, it forms a video signal and also serves to detect a focus state and perform photometry.
Reference numeral 27 denotes a cpu in the camera, which receives and calculates the output (focus, photometry) of the CCD 28 and outputs the result via a contact 27a.
It outputs aperture control information and focus control information. Normally, a motor for driving the aperture and a motor for moving the focus lens are built in the interchangeable lens attached to the video camera 23.
Only the two motor controls based on the control information need be performed in u.

In this embodiment, instead of an interchangeable lens having a built-in motor for driving an aperture and a motor for driving a focus lens, both motors are not built in and a mechanical drive force from the camera body side is received to control the aperture. A lens barrel 21 for moving a focus lens is used. The feature of the present embodiment is that the use of the converter 22 enables the video camera 23 to shoot even an interchangeable lens such as the lens barrel 21 described above.

The converter 22 of this embodiment is mounted between a video camera 23 and a lens barrel 21. For mounting, the bayonet mounts 1 and 3a are used. Converter 2
With the mounting of 2, the contact points 5 and 27a and the contact points 15 and 25a come into contact, and communication becomes possible. In this state, the camera side cpu 27 receives the unique information of the lens from the cpu 25 via the cpu 26, and then transmits the aperture control information and the focus control information based on the output information of the CCD 28 to the contact 27a.
Output through The cpu 26 corrects that the lens-specific information received from the cpu 25 changes due to the interposition of the converter, and converts the information into information suitable for the video camera 23. The cpu 26 of the converter 22 receives the control information via the contact 5 and
12 is rotationally controlled. The rotation of the motors 10 and 12 rotates the interlocking shaft 6 and the transmission member 11a, whereby the holding lens barrel 34 moves in the optical axis direction by the rotation of the gear 33, and moves the focusing lens I to the focusing position. Then, the diaphragm device 30 further narrows the diaphragm opening by the movement of the diaphragm interlocking member 24 so that the proper aperture is obtained. Therefore, even if the lens barrel 21 receives the power for the focusing operation and the aperture control operation from the camera body, the video camera originally has a lens barrel having a built-in focus motor and aperture motor. The camera can be mounted on an auto focus and AE. In addition, a lens barrel that cannot be mounted due to its different mount type could be mounted.

Although the video camera has been described as an example of the camera body in the above-mentioned embodiment, it is needless to say that a similar video camera or a silver halide steel camera can be used.

[0014]

The converter of the present invention combines a camera body having no mechanical drive output, which cannot be originally combined, with a lens barrel driven by a mechanical drive force to capture images. In particular, it is possible to drive the focusing lens moving mechanism and the aperture mechanism in the lens barrel even when combined with a camera body that does not have a mechanical drive mechanism for the lens barrel, enabling shooting. It was done. Further, the converter of the present invention reads lens information such as a focal length from the memory means in the lens barrel, corrects the change due to the interposition of the converter, and converts the information into information adapted to different types of camera bodies. Converted and supplied to the in-camera control circuit in the camera body, receive focusing control information and aperture control information from the in-camera control circuit, and use it to control the drive mechanism in the lens barrel. Therefore, the drive control in the lens barrel can be accurately performed.

In addition, it is possible to mount even a lens barrel and a camera body which are different in mount type and cannot be photographed by being originally mounted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a converter as an embodiment.

FIG. 2 is a perspective view of the converter of FIG. 1;

FIG. 3 is a configuration diagram of a camera system using the converter of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st bayonet mount 5 Contact point 6 Interlocking shaft 10, 12 Motor 11a Transmission member 21 Lens barrel 22 Converter 23 Video camera 24 Aperture interlocking member 25 Cpu 26 having memory means cpu 27 cpu 28 CCD 25a, 27a Contact point I Focus Lens 34 holding barrel 30 aperture device 32 connecting shaft 33 gear

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 7/20 G02B 7/04 G03B 9/02

Claims (1)

(57) [Claims] 1. A camera body used in a first type of camera system for driving a focusing lens moving mechanism and a diaphragm device in a lens barrel using an actuator provided in the lens barrel, and a lens mirror. A lens barrel used in a second type of camera system that mechanically drives a focusing lens moving mechanism and a diaphragm device in the cylinder from the camera body;
A communication unit for communicating with the camera body of the first type and the lens barrel of the second type; and focusing in the lens barrel of the second type. And a driving mechanism including an actuator for mechanically driving the diaphragm lens moving mechanism and the diaphragm device, wherein the communication means includes a control circuit in the camera in the camera body of the first type and a control circuit in the second type. A control circuit in the converter that communicates with the memory means in the lens barrel;
The control circuit in the converter reads lens information such as a focal length from the memory means, corrects the change due to the presence of the converter, and corrects the first information.
To convert the information into information suitable for the camera body of the type and supply it to the control circuit in the camera, and to receive the control information for focusing and the aperture control information from the control circuit in the camera, to control the drive mechanism A converter characterized in that it is used.