JPH0798427A - Intermediate lens barrel - Google Patents

Abstract

PURPOSE:To actuate a focusing lens moving mechanism in a lens barrel and a driving mechanism driving a diaphragm device only when a lens is mounted in an intermediate lens barrel (converter) by providing a means for discriminating whether or not a lens barrel is attached to the converter equipped with the moving mechanism and the driving mechanism. CONSTITUTION:When an interchangeable lens barrel is attached to a mount part 3a, a pin 15 is pressed in to push a switch 16. By pushing the switch 16, a circuit in the converter becomes in an on-state, and communication with a camera main body can be executed through a contact group 5 so as to transmit the inherent information of the lens to a video camera. Simultaneously, driving information for focusing and diaphragm control information are transmitted from the video camera, and motors 10 and 12 are actuated. Since the pin 15 is not pressed in when the interchageable lens barrel is not attached to the mount part 3A of the converter, the switch 16 is turned off, the communication with the camera main body is interrupted, and the motors 10 and 12 are not actuated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter (intermediate lens barrel) for connecting a lens barrel of a different type and a camera body.
It is about.

[0002]

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

In single-lens reflex still cameras, interchangeable lenses, such as those disclosed in Japanese Patent Publication Nos. 63-67171 and 63-67172, which mechanically control the aperture from the camera body and drive the focusing lens, are known. .

On the other hand, as a diaphragm and lens driving method for a lens-interchangeable single-lens reflex camera, a proposal is made to adopt a system in which mechanical movement of the camera body and the lens barrel is eliminated and the lens and diaphragm are driven only by electrical connection. The applicant has already applied (for example, Japanese Patent Publication No. 1-17139). Since this system uses a dedicated actuator for each lens, it has many advantages such as focusing speed, accuracy, and silent operation.

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

However, it is necessary for the user to use (use) the system lens in which the camera and the lens are mechanically interlocked with each other in the system camera in which the camera and the lens are only electrically connected. Convenient, but not realized.

[0007] And, the applicant of the present invention, Japanese Unexamined Patent Publication No. 4-28143
According to Japanese Patent Laid-Open No. 5 (1994), a converter is provided with a drive mechanism for performing a focusing operation and an aperture control in the lens barrel, and a communication means is provided without communicating between the camera barrel and the lens barrel. We have proposed a technology that makes it possible to use a lens barrel that mechanically controls focusing and aperture control in a camera body that has only electrical contacts.

[0008]

However, in the above-mentioned conventional example, when the mount converter is attached to the video camera body, when the video camera body is ready to take a picture, the video camera body and the mount converter are electrically connected. There is a possibility that communication will be performed and the actuator provided in the converter will be activated, which will drain the battery. Also,
It is conceivable that you will shoot without the photographic lens attached.

The present invention aims to improve the above-mentioned prior art.

[0010]

A focusing lens moving mechanism in the lens barrel mounted between the camera body and the lens barrel and a drive mechanism for applying a driving force for driving the diaphragm device are provided. The intermediate lens barrel is provided with a determination unit that determines whether or not the lens barrel is mounted.

[0011]

1 is a sectional view of a converter according to the present invention, FIG. 2 is a perspective view thereof, and FIG. 3 is a block diagram showing the whole camera. Reference numeral 1 denotes a mount having a claw portion 1a, which is fixed to a fixed barrel 3 with a screw 2. Reference numeral 3a is a mount portion to which the interchangeable lens barrel 21 shown in FIG. 3 is attached. Reference numeral 4 denotes an internal fixed portion in which the electric contact group 5 is insert-molded. Reference numeral 6 denotes a connecting shaft that mechanically drives the focusing lens in the lens barrel, and can be retracted in the optical axis direction by a spring 7. 8 and 9 are gears, 10 is AF
It is a motor for (auto focus). Reference numeral 11 is linked with a motor 12 and is connected to a diaphragm driving member 24 in the interchangeable lens barrel by a tip portion 11a. 13a, 1
3b is a circuit board, and 14a and 14b are peculiar to the interchangeable lens such as control of the motors 10 and 12 based on electric signals from the camera body, and F number and focal length written in a memory circuit in the CPU 25 in the lens body. It is an IC that converts lens information so that it can communicate with a video camera. Reference numeral 15 denotes a pin for detecting that the interchangeable lens barrel 21 is pushed in when it is attached, and a switch 16 for contacting the pin is provided on the rear side of the pin 15. Reference numeral 17 is a contact group for executing communication between the converter and the interchangeable lens 21.

Reference numeral 23 is a video camera. 28 is a CCD
In addition to receiving the subject light to form an image signal, it also serves to detect the focus state and perform photometry.
Reference numeral 27 denotes a cpu in the camera, which receives an output (focus, photometry) from the CCD 28 to perform calculation, and through a contact 27a,
The aperture control information and the focus control information are output. Normally, the interchangeable lens mounted on the video camera 23 has a built-in motor for driving the diaphragm and a motor for moving the focus lens.
It suffices to perform two motor control based on the control information in u.

In the present embodiment, instead of the interchangeable lens having the motor for driving the diaphragm and the motor for driving the focus lens, both motors are not built in and the mechanical control force from the camera body side is received to control the diaphragm and focus. The lens barrel 21 for moving the lens is used. In this embodiment, by using the converter 22, the lens barrel 21
Even the interchangeable lens of the type as described above can be photographed by the video camera 23.

The converter 22 of this embodiment is mounted between the video camera 23 and the lens barrel 21. Mounts 1 and 3a are used for mounting. As the converter 22 is attached, communication becomes possible via the contacts 5 and 27 and 17. In that state, the camera side cpu27 is c in the converter.
The lens specific information is received from the cpu 25 via the pu 26, and then the aperture control information and the focus control information are output through the contact 5 based on the output information of the CCD 28. The cpu 26 corrects the lens-specific information received from the cpu 25, which changes due to the interposition of the converter, and converts the lens-specific 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 controls the rotation of both motors 10 and 12. The rotation of the motors 10 and 12 causes the interlocking shaft 6 and the transmission member 11a to rotate, whereby the rotation of the gear moves the focusing lens 1 to the in-focus position, and further the movement of the aperture interlocking member 24 provides proper exposure of the aperture. To narrow down. Therefore, even if the lens barrel 21 receives the power for the focusing operation and the aperture control operation from the camera body, it is originally a video camera of the type in which the lens barrel incorporating the focusing motor and the aperture motor is attached. The camera is attached to the camera 23 for autofocus and AE shooting.

Further, in this embodiment, when the interchangeable lens barrel 21 is attached to the mount portion 3a, the pin 15 is pushed in and the switch 16 is pushed. When the switch 16 is pressed, the circuit in the converter is turned on, communication with the camera body 23 becomes possible through the contact group 5, and the lens specific information is transmitted to the video camera. Along with that, driving information and aperture control information for focusing are transmitted from the video camera, and the motors 10 and 12 are operated.

When the interchangeable lens 21 is not attached to the converter mount 3a, the switch 15 is turned off because 15 is not pushed in, communication with the camera body 23 is cut off, and the motors 10 and 12 do not operate.

[0017]

As described above, the mount converter is provided with a motor for performing focusing operation and aperture control of the photographing lens, and a conversion IC for matching the unique information of the lens with the video camera system used in the main body is provided. Provide a switch that operates when the lens mount is mounted near the mount surface where the lens is mounted, and provide a signal transmission contact in the mount surface where the lens is mounted and on the video camera side mount surface where the converter is mounted. As a result, it becomes possible to use a lens for mechanically controlling focusing and aperture control from the main body, which operates only when the lens is attached to the converter and has only electrical contacts.

[Brief description of drawings]

FIG. 1 is a sectional view of an intermediate barrel according to the present invention.

FIG. 2 is a perspective view of an intermediate barrel according to the present invention.

FIG. 3 is a diagram showing a camera system to which an intermediate lens barrel is applied.

Claims (1)

[Claims] 1. An intermediate lens barrel which is mounted between a camera body and a lens barrel, and which includes a focusing lens moving mechanism in the lens barrel and a drive mechanism for applying a driving force for driving a diaphragm device. An intermediate lens barrel having a determination means for determining whether or not the lens barrel is mounted.