JP2936362B2 - Reverse adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a close-up photographing reverse adapter used for an interchangeable lens used in a single-lens reflex camera, and in particular, a motor for automatic focusing and a motor for driving an aperture are electrically controlled on the camera side. The present invention relates to a close-up photography reverse adapter used in a camera system.

[0002]

2. Description of the Related Art Conventionally, when performing close-up photography, a dedicated lens for close-up photography has been used or a close-up ring has been used. Also, a reverse adapter for mounting the taking lens in reverse has been used to improve the optical performance during close-up photography. The reverse adapter is an adapter for screwing an adapter having a lens mount into a filter screw of the interchangeable lens, attaching the lens mount of the adapter to the mount of the camera, and attaching the interchangeable lens in reverse.

[0003]

In the case of close-up photography using a reverse adapter, since the mount section that is linked with the automatic aperture is on the subject side, the aperture must be determined manually before shooting to the practical aperture. When the focus is determined after the aperture is determined, the finder becomes dark and it is difficult to perform accurate focusing. Further, in the case of a camera in which the aperture is electrically adjusted by the camera body and the exposure is determined by controlling the aperture motor in the interchangeable lens, the aperture cannot be adjusted.

[0004]

The exposure of a subject is determined by opening the photographic lens aperture, and the iris of the photographic lens is moved to a predetermined aperture position by an electric signal of the iris of the camera linked to the shutter release of the camera. The focus of the subject is measured on the camera side, the focusing lens is moved by the motor in the lens by the electric signal, and in the reverse adapter used for the interchangeable lens that focuses, the reverse adapter is attached to the tip of the interchangeable lens A mounting means, a lens mount having the same lens mount and electric contacts as the lens, and a camera mount having the same camera mount and electric contacts as the camera are provided, and the lens mount and the camera mount of the reverse adapter are provided. Connect electrical contacts and reverse adapter camera mount By mounting the mounting of the interchangeable lens, an iris diaphragm adjustment electrically conducted at the camera body, it is possible to determine the exposure by controlling the motor stop in the interchangeable lens.

[0005]

[Function] The reverse adapter is mounted on the front of the interchangeable lens by the screw part that is screwed into the filter screw of the interchangeable lens, and the interchangeable lens is attached to the camera body by the lens mount that has the same lens mount and electrical contacts as the lens of the reverse adapter. Can be installed. On the other hand, by attaching a camera mount that has the same camera mount and electrical contacts as the camera to the interchangeable lens mount, the electrical contacts of the lens mount and the electrical contacts of the camera mount are connected, and the aperture adjustment can be performed with the camera body. The exposure can be determined electronically by controlling the aperture motor in the interchangeable lens.

[0006]

The present invention will be described below with reference to examples.

FIG. 2 is a schematic diagram of a camera system using the reverse adapter of the present invention.
Reference numeral 0 denotes an interchangeable lens, and an interchangeable lens 20 is mounted on the camera body 10 by a camera mount 19 and a lens mount 29. Part of the subject light that has passed through the optical system 21 of the interchangeable lens 20 is transmitted to the main mirror 1 in the camera body 10.
1a is reflected and passes through the pentaprism 12 to reach the photographer's eyes. Another part of the subject light is guided to the AF (autofocus) control unit 14 by the sub mirror 11b.
At the time of photographing, the main mirror 11a of the subject light moves upward, the shutter is opened, and reaches the film surface. Also,
A control circuit 13 processes information from an AF control unit 14 and an AE (auto exposure) control unit 15.
Reference numeral 6 denotes a power supply battery housed in the camera body 10. The contact pins 17a and 17b that contact the contact pins 27a and 27b provided on the interchangeable lens 20 are connected to the control circuit 13 and the battery 16, respectively.

The contact pin 17a is a power supply line for supplying power from the battery 16 in the camera body 10 to the control circuit 23 in the interchangeable lens 20, the AF motor 24, and the AE motor 25. The contact pin 17b is a signal line for transmitting and receiving signals between the control circuit 13 on the camera body 10 side and the control circuit 23 on the interchangeable lens 20 side.
3 is connected.

The interchangeable lens 20, which is configured to be detachable from the camera body 10 having the above configuration, includes:
An AF motor 24 that moves the optical system 21 for focusing;
A control circuit 23 that controls the AE motor 25 that operates the aperture and transmits and receives various signals to and from the control circuit 13 on the camera body 10 is mounted. Contact pins 27a and 27b that contact the contact pins 17a and 17b on the camera body are provided.
Reference numerals 7a and 27b are connected to an AF motor 24 for focus driving, an AE motor 25 for aperture, and a control circuit 23.

Next, the operation of the camera system will be described.

Part of the subject light that has passed through the optical system 21 of the interchangeable lens 20 is transmitted to the AF controller 1 via the sub-mirror 11b.
4, the AF control unit 14 detects the amount of defocus and outputs a signal to the control circuit 13. Control circuit 13
The contact pin 17 outputs a signal for rotating the AF motor 24 for focusing drive based on the calculated amount of movement of the focus lens.
The control signal is transmitted to the control circuit 23 mounted on the interchangeable lens 20 through b and 27b to control the AF motor 24. On the other hand, the AE control unit 15 that controls the exposure detects the luminance and outputs a signal to the control circuit 13. The control circuit 13 transmits a signal for rotating the aperture AE motor 25 to the control circuit 23 mounted on the interchangeable lens 20 through the contact pins 17b and 27b based on the calculated appropriate aperture value, and controls the AE motor 25 to control the aperture. The mechanism 22 is operated.

Next, an embodiment to which the present invention is applied will be described with reference to FIG.

FIG. 1 is a schematic view when a reverse adapter according to the present invention is used. An interchangeable lens 20 is mounted on a camera body 10 via a reverse adapter 30. As described above, part of the subject light that has passed through the optical system 21 of the interchangeable lens 20 reflects off the main mirror 11a in the camera body 10, passes through the pentaprism 12, and reaches the eyes of the photographer. Another part of the subject light is AF-controlled by the sub-mirror 11b.
At the time of photographing, the main mirror 11a moves upward, the shutter is opened, and the subject light reaches the film surface when guided by the control unit 14.

The reverse adapter according to the present invention has 30, 40
The reverse adapter 30 has the same lens mount 39 and the interchangeable lens 20 as those on the interchangeable lens side.
Male screw 3 corresponding to female screw 28 which is a filter screw of
8, and a contact pin 17 provided on the camera body 10
Contact pins 37a and 37b are provided to abut on a and 17b. The contact pins 37a and 37b are connected to the contact pins 47a and 47b of the reverse adapter 40. The contact pin 37a serves as a power supply line for supplying power from the battery 16 in the camera body 10 to the control circuit 23 in the interchangeable lens 20, the AF motor 24, and the AE motor 25 via the contact pin 17a. The contact pin 37b is a signal line for transmitting and receiving signals between the control circuit 13 on the camera body 10 and the control circuit 23 on the interchangeable lens 20 via the contact pin 17b. Reverse adapter 40
Has a camera mount 49 similar to the camera mount 19 of the camera body 10, and is mounted on the lens mount 29 of the interchangeable lens 20.

Next, the operation of the embodiment will be described.

Part of the subject light that has passed through the optical system 21 of the interchangeable lens 20 is transmitted to the AF controller 1 via the sub-mirror 11b.
4, the AF control unit 14 detects the amount of defocus and outputs a signal to the control circuit 13. Control circuit 13
The contact pin 17 outputs a signal for rotating the AF motor 24 for focusing drive based on the calculated amount of movement of the focus lens.
The control signal is transmitted to the control circuit 23 mounted on the interchangeable lens 20 through b, 37b, 47b, and 27b to control the focusing drive AF motor 24 that moves the optical system 21.

On the other hand, the AE control section 15 for controlling the exposure detects the luminance and outputs a signal to the control circuit 13. The control circuit 13 sends a signal for rotating the aperture AE motor 25 based on the calculated appropriate aperture value to the contact pins 17b, 37b, 47.
The control signal is transmitted to the control circuit 23 mounted on the interchangeable lens 20 through b and 27b, the AE motor 25 for driving the aperture is controlled, and the aperture mechanism 22 is operated.

In the schematic diagram of this embodiment, the signal line and the power supply line are each constituted by one for simplification.

[0019]

As described above, when a photographing lens is mounted in reverse to improve the optical performance at the time of close-up photographing, the focus of the subject is measured by the camera side, and the focusing within the lens is performed by an electric signal. By controlling the motor, the focus is adjusted, the aperture is electrically adjusted by the camera body, and the aperture motor is controlled by controlling the aperture motor in the interchangeable lens, so that the photographing can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram when a reverse adapter is used.

FIG. 2 is a schematic diagram of a camera system using a reverse adapter.

[Explanation of symbols]

 Reference Signs List 10 camera body 13 control circuit 14 AF controller 15 AE controller 20 interchangeable lens 23 control circuit 24 AF motor 25 AE motor 30 reverse adapter 40 reverse adapter

Claims (1)

(57) [Claims] An exposure of a subject is determined by opening a photographic lens aperture, and an aperture of the photographic lens is operated to a predetermined aperture position by an electric signal of a iris of the camera interlocked with a shutter release of the camera. In a reverse adapter used for an interchangeable lens that measures the focus on the camera side and controls the motor in the lens by an electric signal to adjust the focus, the reverse adapter (30) has the same lens mount and contact pins (37a, 37b ) as the lens. ) is provided, the camera similar camera mount and the contact pins (47a, a 47b) provided on the reverse adapter (40), said contact <br/> point pin (37a) and said contact pins (47a) and said contact pin
A reverse adapter, wherein the contact pin (47b) and the contact pin (47b) are connected.