JPH04281435A - Converter - Google Patents

Abstract

PURPOSE:To use such a lens barrel that focusing and control are performed by using mechanical power by a camera main body which has only electric contacts by providing a driving mechanism which performs focusing control and stop control in the lens barrel in the converter and providing a means for making a communication between the camera main body and lens barrel. CONSTITUTION:When the converter 22 is mounted, contacts 5 and 27a and contacts 15 and 25a come into contact with each other and the communication becomes possible; and a camera-side CPU 27 outputs stop control information and focus control information through the contact 27a according to the output information of a CCD 28. The CPU 26 of the converter 22 receives the control information through the contact 5 and performs rotation control over motors 10 and 12. An interlocking shaft 6 and a transmission member 11a rotate by the rotation of the motors 10 and 12, and then a holding lens barrel part 34 moves by the rotation of a gear 33 in the direction of the optical axis to move a focusing lens I to a focusing position. Further, a stop device 30 reduces a stop aperture by the movement of a stop interlocking member 24 so that proper exposure is obtained.

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 different types of lens barrels and camera bodies.

0002

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

For single-lens reflex still cameras, there are known interchangeable lenses that mechanically control the aperture and drive the focusing lens from the camera body, as shown in Japanese Patent Publications No. 63-67171 and No. 63-67172. .

On the other hand, as an aperture and lens drive system for an interchangeable-lens single-lens reflex camera, this book proposes a system that eliminates the mechanical linkage between the camera body and lens barrel and drives the lens and aperture using only electrical connections. The applicant has already filed an application (for example, Japanese Patent Publication No. 1-17139). This system uses a dedicated actuator for each lens, so it has many advantages such as focusing speed, accuracy, and silence.

[0005] Furthermore, as compact video cameras become more popular, there is a growing need for video cameras with interchangeable lenses. Even 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]

[Problem to be Solved by the Invention] However, it is difficult to use (divert) a lens for a system in which a camera and a lens are mechanically linked to a camera in a system in which the camera and lens are only electrically connected. Although it is convenient for the user, it has not been realized yet.

[0007]

[Means for Solving the Problems] According to the present invention, a drive mechanism is provided in the converter to perform focusing operation and aperture control within the lens barrel, and further to perform communication between the camera body and the lens barrel. By providing a communication means, it becomes possible to use a lens barrel that mechanically performs focusing and aperture control from the camera body in a camera body that has only electrical contacts.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a converter according to an embodiment, FIG. 2 is a perspective view, and FIG. 3 is a configuration diagram of a camera system with the converter attached. Reference numeral 1 designates a first bayonet mount having a claw portion 1a that can be attached to a mount of a video camera 23, which will be described later, and is fixed to the main body 3 with screws 2. 3a is a second bayonet mount that can be attached to a mount of a lens barrel 21, which will be described later. 4
is an internal fixed part in which a plurality of contacts 5 are insert-molded. Reference numeral 5 denotes a contact point that comes into contact with the contact point 27a on the video camera side when the camera is mounted. 6 is a focusing lens I in the lens barrel 21
It is an interlocking shaft that drives the optical axis, is supported movably in the optical axis direction, and is retractable. Note that the interlocking shaft 6 is urged in the projecting direction by a spring 7. 8 and 9 are transmission gears, 1
0 is an AF motor, and the rotation of an output gear 10a is transmitted to the interlocking shaft 6 via transmission gears 8 and 9. 11 is interlocked with an aperture motor 12, and can be connected to an aperture interlocking member 24 of a lens barrel through a transmission member 11a. 13a, 1
3b is a circuit board; 14a and 14b are CPUs 2 that control the motors 10 and 12 and convert lens-specific information written in the CPU 25 inside the lens so that it can communicate with the video camera;
This is a circuit chip group including 6. Reference numeral 15 denotes a contact point that comes into contact with the contact point 25a of the lens barrel during installation.

In FIG. 3, reference numeral 21 denotes a lens barrel as an interchangeable lens, and as is clear from the figure, an aperture device 30
is driven to open and close by mechanical movement of the diaphragm interlocking member 24 around the optical axis based on movement of the transmission member 11a within the converter 22. 32 is a connecting shaft that connects with the interlocking shaft 6 in the converter 22; 33 is a gear that rotates with the rotation of the connecting shaft 32;
It meshes with a. Reference numeral 25 denotes a CPU within the lens, which serves to store lens-specific information (for example, focal length, aperture control range, etc.) and to communicate with the video camera 23 side. Note that 25a is a contact that contacts the contact 27a of the video camera or the contact 15 of the converter 22, and connects each CPU to enable communication.

23 is a video camera. 28 is CCD
It receives object light and forms a video signal, and also serves as focus state detection and photometry. 27 is a CPU in the camera, which receives the output (focus, photometry) of the CCD 28, calculates it, and via the contact 27a,
Outputs aperture control information and focus control information. Usually, the interchangeable lens attached to this video camera 23 has a built-in motor that drives the aperture and a motor that moves the focus lens, so the CPU inside the interchangeable lens
It is sufficient to perform two motor controls based on the above control information.

In this embodiment, instead of using an interchangeable lens with a built-in aperture drive motor and a focus lens drive motor, both motors are not built in and the aperture control and focus lens are controlled by receiving mechanical driving force from the camera body. This uses a lens barrel 21 that moves the focus lens. The feature of this embodiment is that by using the converter 22, the lens barrel 2
Even with an interchangeable lens of the type 1, it is possible to take pictures with the video camera 23.

The converter 22 of this embodiment is installed between the video camera 23 and the lens barrel 21. Bayonet mounts 1 and 3a are used for mounting. converter 2
2, the contacts 5 and 27a and the contacts 15 and 25a come into contact and communication becomes possible. In this state, the camera side CPU 27 receives lens specific information from the CPU 25 via the CPU 26, and then outputs aperture control information and focus control information via the contact 27a based on the output information of the CCD 28. Note that the CPU 26 corrects changes in the lens-specific information received from the CPU 25 due to the intervention of the converter, and converts it into information suitable for the video camera 23. The CPU 26 of the converter 22 receives the above control information via the contact 5, and controls both motors 10 and 1.
Rotation control of 2. The rotation of the motors 10 and 12 causes the interlocking shaft 6 and the transmission member 11a to rotate, whereby the holding lens barrel section 34 moves in the optical axis direction due to the rotation of the gear 33, thereby moving the focusing lens I to the focusing position. Then, by further moving the diaphragm interlocking member 24, the diaphragm device 30 narrows down the diaphragm aperture to achieve proper exposure. Therefore, even if the lens barrel 21 is of a type that receives power for focusing operations and aperture control operations from the camera body, it is originally a video camera of the type to which a lens barrel with a built-in focus motor and an aperture motor is attached. By attaching it to the 23, it became possible to take pictures with auto focus and AE. Furthermore, it was also possible to attach lens barrels that could not normally be attached due to different mount types.

Although the camera body in the above embodiment has been explained by taking a video camera as an example, it goes without saying that the same implementation can be carried out with a still video camera or a still camera for silver halide.

[0014]

[Effects of the Invention] The converter of the present invention receives lens-specific information from the memory means in the lens barrel, makes corrections due to the addition of the converter, and supplies it to the camera body, and also receives control information from the camera body. This system drives the motor for focusing and aperture control operations, and operates the focusing lens movement mechanism and aperture device inside the lens barrel, which does not have a driving source, so it can be used with different types of camera bodies and lens barrels. This makes it possible to take pictures with auto focus and automatic aperture control.

[0015] Furthermore, it has become possible to mount a lens barrel and a camera body, which have different mount types and cannot normally be attached to take pictures.

[Brief explanation of the drawing]

[Figure 1] Cross-sectional view of a converter as an example

[Figure 2] Perspective view of the converter in Figure 1

[Figure 3] Configuration diagram of a camera system using the converter in Figure 1

[Explanation of symbols]

1 First bayonet mount 5 Contact 6 Interlocking axis 10, 12 Motor 11a Transmission member 21 Lens barrel 22 Converter 23 Video camera 24 Aperture interlocking member 25 CPU with memory means 26 cpu 27 cpu 28 CCD 25a, 27a Contact I Focusing lens 34 Holding barrel part 30 Squeezing device 32 Connecting shaft 33 Gear

Claims (2)

[Claims] 1. A converter installed between a camera body and a lens barrel, comprising a communication means for communicating between the camera body and the lens barrel, and a focusing lens moving mechanism within the lens barrel. and a drive mechanism that provides a driving force for driving the aperture device. 2. The communication means includes a control circuit within the converter that communicates with the control circuit within the camera body and the memory means within the lens barrel, and the control circuit within the converter communicates with the control circuit within the camera body and the memory means within the lens barrel. The lens information is read out and supplied to the camera body control circuit, and the lens information is further received from the camera body control circuit, and is used to control the drive mechanism. The converter according to claim 1.