JP2545514B2 - Rear converter for autofocus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an autofocus rear converter that is used by being mounted between a camera body and a taking lens, and more particularly to a camera body equipped with an AF function and an AF. The present invention relates to an autofocus rear converter that enables AF shooting even with a conventional taking lens by mounting it between a conventional taking lens having no function.

(Prior art) Cameras with interchangeable shooting lenses usually have an AE (automatic exposure) function. To execute this AE, information about the intrinsic aperture value (open aperture value, minimum aperture value) of the shooting lens is displayed. , And automatic iris control or manual iris control switching information needs to be transmitted to the camera body. Therefore, the information transmission electrical contacts having a predetermined relationship are provided at the connecting portions of the camera body and the taking lens.

An example of such an electric contact for information transmission is disclosed in Japanese Patent Application Laid-Open No. 59-162531 of the applicant of the present application.

The information transmitting electrical contacts described in this publication will be described below with reference to FIGS. 6 (A) to 6 (D). Incidentally, FIG. 6 (A) is a front view of relevant parts showing a conventional camera body equipped with an AE function, and FIG. 6 (B) is a perspective view of relevant parts of a conventional taking lens. In order to explain the function of the contact part, FIG. 6 (C) shows the area around the electrical contact of FIG. 6 (A) or (B) as I.
FIG. 6 is a cross-sectional view that is schematically shown by cutting out along line -I.
FIG. 6 (D) is a cross-sectional view schematically showing the peripheral portion of the electrical contact shown in FIG. 6 (A) or (B) along the line II-II.

In these figures, 11 is a camera body, 13 is a camera body mount, 15 is a photographic lens, and 17 is a photographic lens mount.

The mount 13 and the mount 17 are made of, for example, a conductive material obtained by plating brass material. These mounts 13 and 15 are a camera body 11 and a photographing lens 15
It is used for connection with and has the function of electrical ground.

On the mount 13 of the camera body 11, for example, an electric contact group 27 having five electric contacts 21a, 22a, 23a, 24a, 25a is electrically insulated from the mount 13 and can protrude from the mount surface. It is provided (see FIG. 6 (A)). That is, as representatively shown in FIG. 6C, the electrical contacts 21a to 25a and the mount 13 are electrically insulated by the insulating layer 18. In addition, electrical contacts 21a-2
5a normally projects from the surface of the mount 13 (state shown by a solid line in FIG. 6C). And these contacts 21
a to 25a are provided on the mount 13 via a sprig 19 so that when the taking lens 15 is attached to the camera body 11, it can be pushed into the mount 13 while being pressed (shown by a broken line in FIG. 6C). State) is configured.

On the other hand, in the mount 17 of the taking lens 15 corresponding to the electric contact group 27, the electric contact group 29 having five electric contacts 21b, 22b, 23b, 24b, 25b does not protrude from the mount surface. Of course, it is electrically insulated from the mount 17 by the insulating layer 18 and fixed (see FIG. 6 (D)).

Also, one electrical contact is mounted on the mount 13 of the camera body 11.
The mount 31a is provided so as to be electrically insulated from the mount 13 and not to project from the mount surface (see FIG. 6D). Further, one electric contact 31b corresponding to the electric contact 31a is provided on the mount 17 of the photographing lens 15 so as to be electrically insulated from the mount 13 and project from the mount (see FIG. 6C). Has been.

When the above-mentioned taking lens 15 is attached to the above-mentioned camera body 11, each information is transmitted as follows, for example. That is, the open aperture value information is represented by both electrical contact groups 27, 29.
, (21a, 21b), (22a, 22b), (23a, 23b) are transmitted via three pairs of contacts, and the minimum aperture value information is (24a, 24
b), (25a, 25b) is transmitted through two pairs of contacts, and
The switching information for automatic / manual aperture control was transmitted via the electrical contact 31a (details will be described later).

The unique aperture value information is formed as follows, for example. That is, each contact of the electric contact group 29 on the side of the photographing lens is covered with an insulating material at one contact and the other contact is connected to the mount according to the type of the photographing lens. Take action. When the electrical contacts on the camera body side are connected to the contacts thus treated and a voltage is supplied through the pull-up resistor provided on the camera body side, the voltage state of the insulated contacts becomes high. And the voltage state at the contacts connected to the mount becomes low level. Therefore, unique aperture value information including a combination of high and low signals according to the aperture value information can be obtained.

The automatic / manual switching information is formed as follows, for example. The electric contact 31b on the photographing lens side is connected (grounded) to the mount 17 on the photographing lens side in advance.
In such a connection state, for example, when the aperture ring provided in the taking lens is rotated and the ring is set at a predetermined position and the electrical contact 31b on the camera body side contacts the electrical contact 31a on the camera body side, Automatic / manual switching information can be obtained by utilizing two states, that is, a case where the electric contact 31a on the camera body side is not in contact with the electric contact 31b on the camera lens side from a predetermined position.

These pieces of information are taken in by a control unit (not shown) in the camera body 11.

The information transmission electrical contact described above is capable of reliably transmitting the intrinsic aperture value information and the automatic / manual aperture control switching information to the camera body side despite the simple configuration.

By the way, in recent years, some cameras having an interchangeable photographic lens have an AF function (for example, JP-A-60-4916). FIG. 7 is a diagram showing a schematic configuration of a camera equipped with such an AF function.

Such a camera has a mechanism for automatically moving the lens in the taking lens to the in-focus position. That is,
The taking lens 41 for an AF-enabled camera includes a plurality of lenses including a lens 43 that is movable to a focus position, a driving force transmitting means 45 for the movable lens 43, and a unique aperture value of the taking lens 41. A lens ROM (Read Only Memory) 4 for storing information such as shooting conditions according to the lens position moved for focusing (sometimes referred to as unique data of the shooting lens)
7 and.

On the other hand, the camera body 51 for a camera capable of AF is
A control unit 53 for realizing AF and a driving unit 55 for moving the lens in the photographing lens to the in-focus position are provided.

As described above, such a camera with an AF function has a shooting lens 41 with an AF function and a camera body 51 with an AF function.
AF shooting was performed by using and in combination with each other.

(Problems to be solved by the invention) From the standpoint of the person using the camera, the expensive camera body and shooting lens have compatibility without having to replace each new product released by the manufacturer. It is desirable that it can be used forever. In particular, photography enthusiasts purchase many kinds of taking lenses and exchange them at appropriate times for taking pictures. In such a case, there is a problem in that it is a great economic burden for the camera user to replace the photographing lens with a new one each time the camera body becomes new.

The object of the present invention is to solve the above-mentioned problems and not to mention that it is possible to perform AE shooting, but also to mount it between a camera body equipped with an AF function and a conventional shooting lens that does not have the AF function. The objective is to provide an autofocus rear converter that enables AF shooting with a conventional shooting lens.

(Means for Solving the Problems) In order to achieve this object, according to the present invention, a control unit for realizing photographing by automatic focusing and an automatic focusing lens controlled by the control unit are combined. A rear converter for autofocus, which is used by being inserted between a camera body having a driving means for moving to a focal position and a photographing lens, and a body mount to which the mount of the camera body is mounted, The lens mount to which the mount of the photographing lens is attached, the lens system including the movable lens for automatic focusing that is moved by transmitting the driving force from the driving unit, and the driving force of the driving unit. A rear converter for autofocus, comprising a driving force transmission mechanism for transmitting to the movable lens, wherein data specific to the lens system and various types of photographing are provided. A lens ROM for storing a unique data each lens,
Any of the stored unique data of the various photographing lenses is accessed by an identification signal transmitted from the photographing lens side, and the unique data of the accessed photographing lens and the lens system unique data are stored in the camera body side. A lens ROM configured to be read by a control unit, and a lens ROM control electrical contact for transmitting the lens ROM drive voltage, which is provided in the body mount and is sent from the camera body control unit, to the lens ROM A first electrical contact group provided on the body mount for performing information communication between the control unit of the camera body and the lens ROM; and the identification signal provided on the lens mount from the photographing range side. A second electrical contact group for transmitting to the lens ROM, and an image provided on the lens mount and electrically grounded It is equipped with electrical contacts for lens control.

In carrying out this invention, the above-mentioned first electrical contact group is provided so as not to project from the above-mentioned body mount surface, and the above-mentioned lens ROM control electrical contact is provided so as to project from the above-mentioned body mount surface. It is preferable to provide the second electric contact group and the above-mentioned photographing lens control electric contact so as to project from the lens mount surface.

(Operation) A rear converter for autofocus having such a configuration (hereinafter, may be abbreviated as "rear converter").
Is equipped with a camera body of the AF function device, a lens ROM, and
Consider a case where the lens is mounted between a taking lens having an F function or a conventional taking lens having no AF function.

The voltage for driving the lens ROM in the rear converter can be supplied from the camera body side via the lens ROM control contact.

When the photographing lens control contact is provided with a lens ROM on the photographing lens side, for example, the lens ROM can be electrically grounded to stop its function.

The identification signal indicating the type of the photographing lens is transmitted to the lens ROM in the rear converter via the second electric contact group.
This identification signal accesses the data unique to the taking lens stored in the lens ROM in the rear converter.

Further, the accessed data specific to the photographing lens and the data specific to the lens system in the rear converter are transmitted to the camera body side via the first electrical contact.

In the camera body, AE based on these data
A shooting control operation is performed. Further, the focusing lens in the rear converter is driven by the automatic focusing function to control the AF shooting.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. It should be noted that these drawings schematically show the components necessary for the explanation of the present invention, and a part of the description of ordinary parts included in the rear converter, the camera body or the taking lens is omitted.

Further, it is apparent that the size, shape and arrangement relationship of each constituent component are not limited to this illustrated example. Further, in these figures, the same constituents are designated by the same reference numerals.

Configuration of Rear Converter FIG. 1 is a block diagram showing an embodiment of the rear converter of the present invention.

In FIG. 1, reference numeral 611 indicates a rear converter of the present invention. This rear converter 611 is shown in FIG. 6 (A), for example.
A mount 613 for a body to which the mount 13 of the camera body 11 described above is attached using, for example, FIG. 6 (B).
The lens mount 615 to which the mount 17 of the taking lens 15 described above using is attached, the lens system 617 including the movable lens 616 for automatic focusing, and the lens system 61.
7 with lens ROM 619 for storing unique data.
It should be noted that both the body mount 613 and the lens mount 615 can be made of conventionally known materials. The mounts 613 and 615 are electrically connected to each other through, for example, a conductive connecting rod, and further have a function as an electrical ground.

Further, in FIG. 1, reference numeral 675 denotes a first electrical contact group provided on the body mount 613 and connected to different information terminals of the lens ROM 619, respectively. In this embodiment, this first electrical contact group 675 is, for example, three electrical contacts 675.
It consists of a, 675b and 675c.

775 is provided on the lens mount 615, and the identification signal of the photographing lens connected to the lens mount 615 is transmitted to the lens R.
Figure 6 shows a second group of electrical contacts for transmission to OM619. In this embodiment, this electrical contact group 775 is used as, for example, three electrical contacts 7
It consists of 75a, 775b and 775c. In this case, a 3-bit identification signal is formed, which can indicate eight types of lenses. Unique data corresponding to these eight types of lenses can be stored in advance in the lens ROM 619. These electrical contacts 775a, 775b and 775c are respectively connected to information terminals of the lens ROM 619 for accessing the unique data of the photographing lens stored therein.

677 is mounted on the body mount 613 and is the lens described above.
The electrical contacts for controlling the ROM 619 are shown. This lens ROM control electrical contact 677 is the lens from the camera body side.
For example, the power supply voltage is supplied to the ROM 619.
When power is supplied from the control electrical contact 677, the lens ROM 619 is in operation.

Reference numeral 777 denotes a contact for controlling a photographing lens provided on the lens mount 615. The photographing lens control contact 777 is electrically grounded by connecting to the lens mount 615, for example. A detailed description of the function of the electric contact 777 will be given in the section of the usage example of the rear converter described later.

Also, the body side mount 613 has electrical contacts 679a, 679b and 68.
The lens side mount 615 has electrical contacts 779a, 7
It has 79b and 781. The electric contact 679a is an electric contact 779a, the electric contact 679b is an electric contact 779b,
681 are respectively electrically connected to the electrical contacts 781. For example, minimum aperture value information can be transmitted from the photographing lens side to the camera body side via the electrical contacts 679a, 779a, 679b and 779b. Further, through the electrical contacts 681 and 781, it is possible to transmit switching information, for example, whether to perform automatic exposure control or manual exposure control from the photographing lens side to the camera body side.

Reference numeral 621 denotes a ground terminal of the lens ROM 419, which is connected to the body mount 613 or the lens mount 615, for example.

Reference numeral 623 represents a driving force transmission mechanism. This transmission mechanism 623
This is for transmitting the force of a driving source such as a motor provided in a functional camera body to a movable lens 616 provided in a rear converter 611 to contribute to automatic focusing.

 An example of this transmission mechanism will be described.

A clutch mechanism is provided on each of the camera body and the rear converter. The power of the drive source on the camera body side is transmitted to the inside of the rear converter via these clutch mechanisms. The transmitted driving force is converted into a force for moving the movable lens in the optical axis direction by the gear mechanism and the helicoid screw. The transmission mechanism can be modified into various structures according to the design.

By the way, in this embodiment, 675a, 675b, 675c, 679a, 679b
And each electrical contact indicated by 681 to the body mount 613,
Each contact 21b, which has already been described with reference to FIGS. 6 (B) to (D),
22b, 23b, 24b, 25b, and 31b are provided with the same arrangement relationship and mechanism. That is, each contact 675a, 675b, 675c, 679a and 679b is isolated from mount 613 and
It is provided so that it does not protrude from the surface. In addition, contact point 68
1 is provided so as to be insulated from the mount 613 and project from the mount 613. Also, electrical contact 677 for lens ROM control
For this, the contact 677 is provided at a predetermined position of the mount 613 so as to be capable of projecting from the surface of the mount 613 and electrically insulated from the mount 613.

Also, the contacts 775a, 775b, 775c, 779a, 779b, and 781 are mounted on the lens mount 615, and the contacts 21a, 22a already described with reference to FIGS. 6 (A), (C), and (D) are used. , 23a, 24a,
The layout and mechanism are similar to those of 25a and 31a. That is, the contacts 775a, 775b, 775c, 779a and 779b are provided so as to be insulated from the mount 615 and project from the surface of the mount 615. Further, the contact 781 is provided so as to be insulated from the mount 615 and not protrude from the mount 615. Also, regarding the electrical contact 777 for controlling the shooting lens, mount this contact 777 at a predetermined position of the mount 615.
It is provided so that it can project from the surface of 615 and is electrically insulated from the mount 615.

Usage Example of Rear Converter Hereinafter, a usage example of the above-described rear converter of the present invention will be described. A suitable camera body to which the rear converter 611 of the embodiment can be attached is, for example, a camera body having an AF function, which will be described below with reference to FIG. Further, as the photographing lens that can be mounted on the rear converter 611, for example, the photographing lens already described with reference to FIG. 6 (B) or the AF function equipment described below with reference to FIG. There is a shooting lens.

<Camera body equipped with AF function> First, referring to FIGS. 2A and 2B, a camera body equipped with an AF function suitable for the rear converter 611 of the present invention (hereinafter also abbreviated as AF body). There is an example). FIG. 2 (A) is a block diagram showing the internal structure of this AF body, and FIG. 2 (B) is a front view of the essential parts schematically showing this AF body.

This AF body 101 is a rear converter 611 of the present invention.
(See FIG. 1) The electrical contacts 175a, 175b and 175c corresponding to the electrical contacts 675a, 675b and 675c, the determination contact 177 corresponding to the control electrical contact 677 of the lens ROM619 provided in the rear converter, and the rear converter. Electrical contacts 679a, 679b and
Electrical contacts 179a, 179b and 181 corresponding to 681 are provided on the mount 103 of the AF body 101, respectively. Further, the AF body 101 includes a control unit 105 for realizing shooting with AE and AF functions, a driving unit 107 for driving a movable lens 616 in the rear converter 611, and the like.

FIG. 2B shows the above-mentioned electric contacts 175a, 175b, 175c, 1
77 shows a state in which 77, 179a, 179b and 181 are mounted on the AF body 101. That is, the contacts 175a, 175b, 175c, 179a, 179b are mounted on the mount 103 of the AF body 101, and the contacts 21a, 22a, 23a, 24a, 25 already described with reference to FIG.
The layout and mechanism are the same as a and 31b.
That is, the contacts 175a, 175b, 175c, 179a and 179b are provided so as to be insulated from the mount 103 and project from the surface of the mount 103 (see FIG. 6C). Further, the contact 181 is provided so as to be insulated from the mount 103 and not project from the surface of the mount 103 (see FIG. 6D). further,
The contact point 177 is provided at a predetermined position of the mount 103 so as to project from the mount 103 and be electrically insulated from the mount 103. The mount 103 can be made of a conventionally known material and functions as an electrical ground.

<Photographing Lens with AF Function> Next, referring to FIGS. 3A and 3B, a photography lens with AF function equipped with the rear converter 611 of the present invention (hereinafter, abbreviated as AF lens) There is also an example). FIG. 3 (A) is a block diagram showing the internal structure of this AF lens, and FIG. 3 (B) is a perspective view of the essential parts schematically showing this AF lens.

In these figures, 71 indicates an AF lens. 73 is this AF
The lens ROM of the lens is shown. The lens ROM 73 stores the unique data of the taking lens for realizing the AE and AF operations. Reference numeral 75 denotes an electric contact group which is respectively connected to different information terminals of the lens ROM 73 and which is provided corresponding to the second electric contact group 775 of the rear converter 611. Therefore, in this case, the electrical contact group 75 is composed of three electrical contacts 75a, 75b, 75c. Reference numeral 77 indicates an electrical contact for controlling the lens ROM of the AF lens. The control electrical contact 77 is normally for supplying, for example, a power supply voltage from the AF body 101 described above to the lens ROM 73. When power is supplied from the control electrical contact 77, the lens ROM 73 is in operation. Also 74
Indicates a ground terminal. The ground terminal 74 can be connected to, for example, a mount of a taking lens.

Reference numerals 79a and 79b denote electric contacts provided corresponding to the electric contacts 779a and 779b of the rear converter 611, respectively. These electrical contacts transmit, for example, minimum aperture value information to the camera body side. In the configuration shown in FIG. 1, a binary digital signal, that is, minimum aperture value information represented by (01) is transmitted to the camera body side by the electric contacts 79a and 79b. 81 is an electrical contact 781 of the rear converter 611
The electrical contacts provided corresponding to This electrical contact transmits the switching information of automatic / manual aperture control to the camera body side. Next, the above-mentioned electrical contacts 75a, 75b, 75c, 79a, 79b and 81
FIG. 3B shows a state in which the control contact 77 and the control electrical contact 77 are mounted on the taking lens. FIG. 3B is a perspective view showing the AF lens. Each contact point indicated by 75a, 75b, 75c, 79a, 79b and 81 is mounted on the mount 85 of the AF lens 71, as shown in FIG.
Each contact 21b, 22b, 23b, 24b, 25 already described using (D)
It is provided with the same layout relationship and mechanism as b and 31b.
That is, the contacts 75a, 75b, 75c, 79a and 79b are provided so as to be insulated from the mount 85 and not to project from the surface of the mount 85. Further, the contact 81 is provided so as to be insulated from the mount 85 and project from the mount 85. Further, the contact 77 is provided at a predetermined position of the mount 85 so as to be capable of protruding from the mount 85 and electrically insulated from the mount 85. The mount 85 can be made of a conventionally known material and functions as an electrical ground (ground).

Reference numeral 83 indicates a switching means for switching the function of the electric contact group 73. In the case of this embodiment, the switching means 83 can be configured as described below. That is, an electrical contact 75 connected to one information terminal 73a of the lens ROM 73.
The emitter of PNP transistor Tr1 as an electronic switch is connected to a. Similarly, the emitter of the PNP transistor Tr2 is connected to the electric contact 75b connected to the information terminal 73b, and the PNP transistor T is connected to the electric contact 75c connected to the information terminal 73c.
Connect the emitter of r3. Further, the base of each transistor is connected to the lens ROM control electrical contact 77 connected to the lens ROM 73. Further, whether the collector of each transistor is grounded or opened by an electric circuit is preliminarily treated according to the type of the photographing lens. For example, in the case of the configuration example shown in FIG. 3 (A), the collector of the transistor is open in Tr1 and is grounded in Tr2 and Tr3.
In such a case, when the potential of the control electrical contact 77 becomes substantially equal to the ground, each transistor is turned on, and a voltage is supplied to the electrical contacts 75a, 75b, 75c via pull-up resistors as in the conventional case. In case of
The voltage state of the contact 75a becomes high level, and the voltage state of the contacts 75b and 75c becomes low level.

Further, the taking lens 71 of the present invention comprises a lens system including a lens 87 which is movable to a focus position, and a driving force transmitting means 89 for transmitting a driving force for driving the lens 87 from the camera body. Get

<Usage Example 1 of Rear Converter> FIG.
FIG. 9 is a configuration diagram schematically showing a state in which the F body 101 is mounted between the F body 101 and a conventional taking lens 15 that does not have an AF function, which has already been described using FIG. 6B.

In such a configuration, the conventional taking lens 15 is
As described above, for each contact of the electrical contacts 21b, 22b and 23b, one contact is covered with an insulating material and the other contact is connected to the mount. is there. Therefore, when a predetermined voltage (for example, the power supply voltage for driving the lens ROM) is applied to each contact 775a, 775b and 775c of the second electrode group of the rear converter 611 via a pull-up resistor, the contacts 21b, 22b and 23b are contacted. Depending on whether they are isolated or grounded, these contacts 775a, 7
The voltage state at 75b and 775c changes. Therefore, the identification signal of the photographing lens can be transmitted to the lens ROM 619 of the rear converter 611 by the combination of the voltage states. In this case, eight kinds of signals can be shown by the second electrode group 775. Further, in this case, in the lens ROM 619, peculiar data corresponding to these eight kinds of signals are stored in advance, and these peculiar data are read by these identification signals.

On the other hand, from the control unit 105 of the AF body 101 to the contact 177 and the contact 6
The voltage for driving the lens ROM via the rear converter 6
11 are supplied to the lens ROM 619, and the lens ROM 619 operates as specified.

Rear converter 611 and AF body 1 in predetermined operation
Information is exchanged with 01, for example, as follows. AF
Reset signal (RE) from the body control unit 105 to contact 175a
And 675a to the lens ROM 619. In addition, the clock signal (CK) is sent from the control unit 105 of the AF body to the contacts 175b and 6
It is supplied to the lens ROM 419 via 75b.

On the other hand, in accordance with the above-mentioned reset signal and clock signal, predetermined information such as position data of the lens system 617 in the rear converter from the lens ROM 619 of the rear converter 611 to the control unit 105 of the camera body via the electrical contacts 675c and 175c. Are transmitted serially.

The minimum aperture value information is the contact points 24b, 779a, 679a and 179a.
And the contact point 25b, 779b, 679b and 179b through the taking lens 1
It is transmitted from the 5 side to the control unit 105.

Regarding switching information of automatic diaphragm control or manual diaphragm control, when the diaphragm ring (not shown) of the photographing lens 15 is rotated, the contact 31b of the photographing lens contacts the contact 781 of the rear converter 611, and It is transmitted by two states when they do not touch. In this case, the contact 681 of the rear converter 611 and the contact 181 of the camera body 101 are in electrical contact beforehand.

The driving force of the driving source 107 provided in the AF body 101 is transmitted to the movable lens 616 by the driving force transmission mechanism 623 of the rear converter. Then, the movable lens 616 moves to the in-focus position.

With such a configuration, it is possible to perform shooting with AF and AE operations using a conventional shooting lens that does not have an AF function.

<Rear Converter Usage Example 2> FIG.
FIG. 3 is a configuration diagram schematically showing a state of being mounted between the F body 101 and the AF lens 71 described above.

In such a configuration, since the electrical contact 777 provided on the lens mount 615 is electrically grounded, the lens ROM control electrical contact 77 of the AF lens 71 that contacts the electrical contact 777 must be grounded. become. Therefore, the lens ROM 73 in the AF lens 71 is stopped. On the other hand, each PNP transistor of the switching means 83 in the AF lens 71 is turned on. In such a state, the rear converter
When a predetermined voltage (for example, the power supply voltage for driving the lens ROM) is applied to each contact 775a, 775b, and 775c of the second electrode group 611 through, for example, a pull-up resistor, it has already been described with reference to FIG. The voltage state of these contacts 775a, 775b and 775c changes depending on the connection state between the collector of each PNP transistor and ground. Therefore, the identification signal of the AF lens can be transmitted to the lens ROM 619 of the rear converter 611 by the combination of the voltage states.

The following processing can be performed in the same manner as in the usage example 1 already described with reference to FIG.

With such a configuration, it is possible to stop the AF function provided in the AF lens and use the rear converter of the present invention to perform shooting by the AF and AE operations.

Modification Note that the rear converter of the present invention is not limited to the above-described embodiment.

For example, in the above embodiment, the first electrical contact group 675
And the second electric contact group 775 has three electric contacts. However, the number of the electrical contacts forming these electrical contact groups can be changed according to the design of the camera body to which the rear converter is attached and the taking lens.

Furthermore, the mechanical structures of the camera body, the mount of the taking lens and the rear converter, and the electrical contacts described in the above embodiments are merely examples, and these structures may be variously modified within the scope of the object of the present invention. Can be added. For example, the concavo-convex state with respect to the mount of the electric contact provided for each component can be changed to the concavo-convex state opposite to that of the embodiment.

(Effects of the Invention) As is apparent from the above description, the rear converter of the present invention includes an AF function-equipped camera body and an AF converter.
When mounted between a conventional photographic lens that does not have a function or a photographic lens equipped with an AF function, this lens drive voltage is applied from the camera body side to the lens ROM of the rear converter via the electrical contacts for lens ROM control. Supplied. Further, for the photographing lens equipped with the lens ROM, the operation of the lens ROM is stopped by the electric contact for controlling the photographing lens to bring it into the same functional state as the conventional lens. Further, the identification signal of the photographing lens is taken into the lens ROM of the rear converter via the second electric contact group. Further, the unique data of the taking lens and the unique data of the rear converter are transmitted from this lens ROM to the camera body side via the first contact group. As described above, the rear converter for autofocus of the present invention causes the combination of the rear converter and the photographing lens to function as if it were a single new AF lens. Therefore, the camera body calculates the lens drive amount as in the case of a normal AF lens. Further, in response to this, the focusing lens in the rear converter is moved to the focusing position.

For this reason, AE shooting is possible, and AF shooting with a conventional shooting lens is also possible by mounting it between the camera body with AF function and the conventional shooting lens that does not have AF function. It is possible to provide a rear converter for auto focus.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a rear converter of the present invention, and FIG. 2 (A) is a block diagram showing an example of a camera body having an AF function suitable for mounting the rear converter of the present invention. FIG. 3B is a front view of an essential part showing an example of a camera body equipped with a rear converter of the present invention and having a suitable AF function, and FIG. FIG. 3 (B) is a block diagram showing an example of a photographic lens equipped with functional equipment, FIG. 3 (B) is a perspective view of the essential parts showing an example of a photographic lens equipped with the AF converter suitable for mounting the rear converter of the present invention, and FIG. FIG. 5 is a block diagram showing a usage example 1 of the rear converter of the invention, FIG. 5 is a block diagram showing a usage example 2 of the rear converter of the invention, and FIGS. 6 (A) and 6 (B) are views of a conventional camera equipped with an AE function. Explanatory drawing, FIG. 6 (C) and D) is a sectional view showing a conventional and information transmitting electrical contacts according to the present invention, FIG. 7 is a block diagram showing a conventional camera AF featured. 71 …… Shooting lens, 73 …… Lens ROM 74 …… Ground terminal, 75 …… Electric contact group 77 …… Electric contact for lens ROM control 79a, 79b, 81 …… Electric contact 83 …… Switching means 85 ...... Mounting on the shooting lens side 87 …… Moveable lens for AF 89 …… Driving force transmission means Tr1 to Tr3 …… PNP transistor 101 …… Camera body 103 …… Mounting on camera body side 105 …… Control section, 107… … Lens driving means 175 …… Electrical contact group, 177 …… Judgment electrical contact 179a, 179b, 181 …… Electrical contact 611 …… Rear converter 613 …… Body mount 615 …… Lens mount 617 …… Focusing Lens system 619 …… Rear converter lens ROM 621 …… Ground terminal 623 …… Driving force transmission mechanism, 675 …… First electrical contact group 677 …… Rear converter lens ROM control electrical contacts 679a, 679b, 681, 779a, 779b, 781 ... electrical contacts 775 ... second electrical contact group.

Claims (2)

(57) [Claims] Claims: 1. A camera body comprising a control unit for realizing photographing by automatic focusing and a driving unit controlled by the control unit for moving an automatic focusing lens to a focusing position, and a photographing lens. An autofocus rear converter that is used by being inserted between the camera body mount, a body mount to which the camera body mount is mounted, a lens mount to which the photographing lens mount is mounted, and a drive unit driven by the driving means. Autofocus comprising a lens system including a movable lens for automatic focusing that is moved by transmitting force, and a driving force transmission mechanism for transmitting the driving force of the driving means to the movable lens In the rear converter for a lens, which is a lens ROM that stores each of the data specific to the lens system and the specific data of various shooting lenses, One of the stored unique data of the photographing lenses is accessed by an identification signal transmitted from the lens side, and the unique data of the accessed photographing lens and the unique data of the lens system are controlled by the camera body side. A lens ROM configured to be read by a unit, a lens ROM control electrical contact for transmitting to the lens ROM a voltage for driving the lens ROM, which is provided in the body mount, and is sent from a control unit of the camera body, A first electrical contact group provided on the body mount for performing information communication between the control unit of the camera body and the lens ROM; and the identification signal provided on the lens mount from the photographing lens side Second electric contact group for transmitting to lens ROM, and photographing lens provided on the lens mount and electrically grounded A rear converter for autofocus, which is equipped with electrical contacts for control. 2. The first electrical contact group is provided so as not to project from the body mount surface, the lens ROM control electrical contact is provided so as to project from the body mount surface, and the second electrical contact group and The rear converter for autofocus according to claim 1, wherein the electric contact for controlling the photographing lens is provided so as to be able to project from the lens mount surface.