JPH0118406B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical accessory such as an interchangeable lens, which improves the reliability of an electrical connection terminal for electrical connection with a camera body. It is related to goods.

[Conventional technology]

Recently, interchangeable lens cameras that use a rotatable bayonet mount that connects or detaches the mounts of the interchangeable lens and camera body by rotating clockwise or counterclockwise, There is an electric circuit on each side of the camera body and information for automatic exposure control.
Various types of information, such as information for automatic focus adjustment, have come to be exchanged with each other, and it has become known that a large number of electrical connection terminal groups are provided near the mount for the purpose of exchanging signals.

That is, as shown in FIGS. 7 to 11,
A camera side bayonet mount 1, a locking pin for fixing when the lens side mount is attached, and a contact seat 3 forming a camera side connector are fixedly installed on the front surface of the camera body 4 of camera A. In the illustrated example, contact pins 3a consisting of contact pins 3a ₁ to 3a ₇ (seven in the example) are urged by contact springs 3b consisting of contact springs _{3b 1} to 3b ₇ so as to protrude at the same height from the front surface of contact seat 3. The contact pins 3a ₁ to 3a ₇ are connected to a camera body electric device 6 via a flexible printed board 5. On the other hand, the interchangeable lens B holds a photographing lens group 9, has a lens side bayonet mount 8 on its rear end surface, and a lock pin 2 on the camera side.
A locking groove 9 in the form of an elongated hole that engages with the lens side connector and a contact seat 10 constituting the lens side connector are fixedly provided, and the contact seat 1
0 has a plurality of contacts 10a ₁ to 1 (seven in the illustrated example).
A contact group 10a consisting of 0a ₇ is fixed so that its rear end is on the same plane, and the contacts 10a ₁ to 10a ₇
is connected to a lens-side electric device 12 via a flexible printed board 11.

3 on the inner circumference of camera side bayonet mount 1.
Bayonet pawls 1a ₁ to 1a ₃ are formed on the lens side bayonet mount 8.
Three bayonet pawls 8a ₁ to 8a ₃ that engage with a ₁ to 1a ₃ , respectively, are formed in a distributed manner. When the mounting is completed, the locking pin 2 on the camera side engages with the locking groove 9 on the lens side, thereby maintaining the mounted state.

When the interchangeable lens B is attached to the camera A with its respective bayonet mount, the mount surfaces of both lenses overlap each other as shown in FIG. 7, and the camera body side contact pin group 3a is connected to the lens side contact 10a. are brought into contact with appropriate contact pressure by the contact spring 3b, and each contact pin 3a ₁ to 3a ₇ and each contact point 10a ₁ to 10a ₇ are electrically connected, respectively, and the camera body side electric device 6 and the lens side electric device 12 exchange electrical signals with each other.

Regarding the connection operation of both contacts when the interchangeable lens B is attached, as shown in FIG. 3
The contact pins 3a ₇ to 3a ₁ are sequentially connected to the lens side contact seat 10.
When the contact springs _3b7 to 3b1 are compressed by being pressed by the end slope 10b, the contact springs 3b7 to _3b1 are alternately pressed and slid onto the surface of the lens side contact seat 10 and the lens side contacts _10a1 to _10a7 . Contact 3 as shown in Figure 11
a ₁ and 10a ₁ , 3a ₂ and 10a ₂ , . . . 3a ₇ and 10a ₇ are in contact with each other on the same plane.

[Problems to be solved by the present invention]

However, in the conventional connection connector as shown in FIGS. 10 and 11, each time the interchangeable lens B is rotated and attached to the camera A, the lens side contact 10a ₁ first comes into sliding contact with the camera side contact pin 3a ₇ . Thereafter, it comes into sliding contact with the camera side contact pins 3a ₆ to 3a ₁ and the rotational mounting is completed.

Below, when rotating the lens side contact 10a ₂
are in sliding contact with the camera side contact pins _3a7 to _3a2 , and the lens side contact _10a3 is in sliding contact with the camera side contact pins _3a7 to _3a3 ...The lens side contact _10a6 is in sliding contact with the camera side contact pins _3a7 and _3a6. Sliding contact and lens side contact 10a ₇
makes sliding contact only with the camera side contact pin _3a7 .

If the lens-side contacts 10a ₁ to 10a ₇ are fixed, foreign matter such as dust and dust may adhere to them due to the fact that they are arranged at the same height as the connector surface of the lens-side contact seat 10 or in a recessed state. There is a high degree of In the conventional connection connector described above, foreign matter attached to the lens side contacts 10a ₁ to 10a ₇ is removed from the camera side contact pin 3 during the mounting rotation.
_A7 to _3a1 are cleaned by sliding on the pins (on the surface). Here, the lens side contact 10
a ₁ to 10a ₆ are connected to the camera side contact pins 3a ₇ to 3a ₁ at least once from end to end (Figs. 10 and 11).
The camera side contact pin 3a 7 is cleaned by sliding it to the left and right ends (as shown in the figure), but when the lens side contact 10a ₇ is completely rotated, the camera side contact pin 3a ₇ is moved to one end (Figs. 10 and 11). Since it slides only from the right end (at the right end) to approximately the center, reliable cleaning may not be performed and foreign matter may not be removed. Also, each time the interchangeable lens B is rotated and attached to the camera A, the lens side contacts 10a ₁ to 10
The foreign object attached to a ₆ is the contact pin 3 on the camera side.
_a7 to _3a2 , the foreign matter is carried in the direction of the lens side contact _10a7 and accumulates at the lens side contact _10a7 , and the degree of foreign matter adhering to the lens side contact _10a7 increases. The presence of foreign matter causes poor contact and the like, resulting in the problem that normal operation of the camera and lens cannot be guaranteed.

Conventionally, as a countermeasure against poor contact due to dirt adhering to the contacts, a special adhesion removal pin was provided on the lens side, separate from the contact pin, to remove dirt adhering to the concave contacts on the camera side by rotating both mounts. A device that cleans when installed is proposed as Utility Model Application No. 120440/1986. However, this proposal merely scrapes out the dust from the control electrical contact, which is located in the middle of the camera side contact group and is retracted into a concave state, using the above-mentioned cleaning-specific dirt removal pin. be. Therefore, the first
None of the above-mentioned proposals can deal with the problem of dust adhesion on the lens-side contact, where the number of times of sliding contact in FIGS. 0 and 11 is one. Also, conventionally,
A device in which the mount also serves as a means for electrical connection is known as JP-A-58-83824.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical accessory that can improve the reliability of contact between a group of contacts and prevent malfunctions.

[Means to achieve the purpose]

The structure of the present invention for achieving the above-mentioned object is as follows:
In order to facilitate understanding, the explanation will be made using FIGS. 1 to 3 as examples.

Lens side contacts 10a 1 to 10a ₇ are formed on an interchangeable lens that is rotatably attached to a camera body having camera side contact pins _{3a 1 to} 3a ₇ , and when the camera body is rotatably attached, the camera side contact pin group 3a The lens-side bayonet mount ₈
connected in parallel.

[Effect]

Dust attached to lens side contacts 10a ₁ to 10a ₇ ,
Foreign matter such as dust is cleaned by the mounting operation of the interchangeable lens on the camera body, that is, by the sliding movement with the camera-side contact pins 3a ₁ to 3a ₇ accompanying the rotation operation. The lens-side contact _10a7 , which is the rear in the rotational direction and whose surface is not completely cleaned of foreign matter due to the small number of sliding movements, is also connected in parallel with the lens-side bayonet mount 8. Even if the lens-side contact _10a7 has poor conductivity with the camera-side contact pin _3a7 due to dust or the like, the lens-side contact _10a7 and the lens-side bayonet mount 8 are electrically connected in parallel. Therefore, the electrical connection between the lens-side bayonet mount 8 and the camera-side bayonet mount 1
Electrical continuity can be achieved reliably.

Note that by electrically connecting the same line using two systems, the reliability of the electrical connection between the interchangeable lens and the camera body is greatly improved.

〔Example〕

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. Constituent elements similar to those of the conventional example are given the same reference numerals, and their explanations will be omitted.

In FIG. 1, 21 is an electronic circuit mounted on the camera A, 22 is a power source such as a battery that is also housed in the camera body, and 23 is a power source that is supplied with power from the power source 22, and is connected to the electronic circuit 21 and the lens described below. 24 is an analog switch that turns on and off the power supply to the motor (described later) mounted on the lens side; 1 is the camera side bayonet mount provided on the camera body; 26 is a lens mounting detection switch provided with an input signal line for the electronic circuit 21 and disposed near the camera-side bayonet mount 1; 27 is a lens mounting/detaching response member for operating the lens mounting detection switch 26. The lens attachment/detachment response member 27 is the camera side bayonet mount 1.
It is a swinging member pivotally mounted on the back side of the lens, and has two arms on both sides of the pivot point, one of which is driven by engaging a part of the camera mount of the lens. , the other arm is the lens attachment detection switch 2.
It is designed to press one switch piece of 6.

The lens device detection switch 26 has two switch pieces that are separated from each other when the lens is not attached, and when the lens is attached, the two switch pieces contact each other to connect the input terminal of the electronic circuit 21 and the constant voltage output. It is designed to be connected to the output terminal of the circuit 23.

As mentioned above, the contact seat 3 for wiring connection is provided in the lower inner peripheral area of the camera side bayonet mount 1, and the contact seat 3 has each of the contacts 10a ₁ to 10a ₇ provided on the lens side. A large number of contact pins _3a1 as a group of electrical connection terminals on the camera body side that come into contact with the
~ _3a7 is provided. Here, each contact pin 3
A ₁ to 3a ₇ are respectively connected to wiring lines L ₁ to _{L 7} on a printed wiring board 5 attached to the camera body.

Furthermore, the wire L ₇ ′ connected in parallel to the wire L ₇ is connected to the camera side bayonet mount 1 as described below.
Wires _{L14' connected in parallel to L14 are} respectively connected to the lens-side bayonet mounts 8.

The wiring L ₁ connected to the contact pin 3a ₁ serves as a motor power line for supplying power from the power supply 22 inside the camera body to the motor inside the lens (described later), and as mentioned above, it is connected to the analog switch 2.
4 is provided.

The wiring _L3 connected to the contact pin _3a3 is a lens 1C power line connected to the lens attachment detection switch 26 and the input terminal of the electronic circuit 21. In addition, the wiring L ₂ connected to the contact pin 3a ₂ is a power ground line (power ground line), and the wiring L ₂
is connected to the negative pole of the power supply 22.

The wiring L ₇ connected to the contact pin 3a ₇ is connected to the ground wire of the electronic circuit on the lens side, which will be described later, and the wiring L ₇ is connected to the power supply 22 together with the installation terminal of the electronic circuit 21 on the camera body side. connected to the negative terminal of

Wiring L ₄ ~ connected to contact pins 3a ₄ ~ 3a _6
L6 is a signal line for transmitting and receiving signals between the electronic circuit 21 on the camera body side and the electronic circuit on the lens side, and each wiring _L4 to _L6 is a signal line for transmitting and receiving signals between the electronic circuit 21 on the camera body side and the electronic circuit on the lens side.
1 signal terminal.

Interchangeable lenses that are removably attached to camera bodies that have the above-mentioned configuration include:
A focusing drive motor 29, a switch device for switching the direction of power supply to the motor 29, and the motor 29.
electronic circuit 2 on the camera body side.
An electronic circuit 30 that sends and receives various signals to and from 1.
and a lens side bayonet mount 8 which is removably fitted to the camera side bayonet mount 1, and a contact seat 3 on the camera body side which is arranged in the lower inner peripheral area of the lens side bayonet mount 8. A contact seat 10 that faces the contact seat 10 is provided.

As shown in the figure, the contact seat 10 provided on the interchangeable lens side has contact pins 3a _{1 to 3} on the camera body side.
Seven contacts 10a ₁ to 10a 7 are provided as a group of electrical connection terminals on _the optical accessory side that can come into contact with 3a ₇ , and these contacts 10a ₁ to 10a ₇ are individually connected with wiring L ₈ to _{L 14 .} is connected.

Wires L ₈ and L ₉ are connected to the motor 29 via a switch device that will be explained later, and other wiring
Compared to _L10 to _L14 , it is a power line for flowing a large current.As will be explained later, _L8 is a motor power line, and _L9 is a power ground line for grounding one pole of the motor 29. It's summery.

The wiring L ₁₀ connected to the contact 10a ₃ serves as an electronic circuit power supply line for supplying current to the lens side electronic circuit 30, and is connected to the power terminal of the electronic circuit 30 and also connects to the contacts 10a ₃ and 3a. It is designed to be connected to wiring _L3 on the camera body side via wire _L3 .

The wiring L ₁₄ is connected to the ground terminal of the electronic circuit 30 and also to the wiring L ₇ on the camera body side via contacts 10a ₇ and 3a ₇ , and is connected to the wiring L 7 on the interchangeable lens side of the electronic circuit 30. It forms the ground line (signal ground line).

The wires L ₁₁ to _{L 13} are connected to the signal terminals of the electronic circuit 30 and are also separately connected to the contacts 10a ₄ to 10a ₆ , and are also connected to the contacts 10a 4 to _{10a 6} on the lens side.
10a ₆ and contact pins 3a ₄ to 3a ₆ on the camera body side to be separately connected to wirings L ₄ to L ₆ on the camera body side, respectively. That is,
Wiring lines L ₁₁ to _{L 13} serve as signal lines on the lens side.

The switch device for switching the direction of power supply to the motor 29 consists of one NPN transistor and one
It consists of two sets of four transistors T ₁ to T ₄ paired with PNP transistors, one pair is connected to one pole of the motor 29, and the other pair is connected to the other pole of the motor. ing. Also, each pair
The emitters of PNP transistors T ₁ and T ₂ are connected to the wiring L ₈ provided on the interchangeable lens side.
The wiring L ₈ is connected to the wiring L ₁ on the camera body side via a contact 10a ₁ in the contact seat 10. (In other words, the wiring L ₈ and the wiring L ₁ constitute a power supply line for supplying power from the power source 22 to the motor 29.) One pole of the motor 29 is connected to a paired PNP transistor T ₁ . The motor 29 is connected to the collector of each of the NPN transistors _T4 , while the other pole of the motor 29 is connected to the collectors of each of the paired PNP transistors _T2 and _T3 . On the other hand, the emitters of each pair of NPN transistors _T3 and _T4 are connected to the wiring _L9 . The wiring _L9 is a power ground line provided on the interchangeable lens side, and the negative pole side of the motor 29 is connected to the contact point _10a2.
It is connected to the contact pin _3a2 on the camera body side through the wire _L2 on the camera body side, and to the negative pole of the power source 22 through the wiring L2 on the camera body side.

The electronic circuit 30 is provided with control terminals for controlling each of the transistors T ₁ to _{T 4} of the switch device, and each control terminal and the base of each transistor T ₁ to _{T 4} are connected to the transistors T 1 to T 4 related to motor control. Connected by main signal wire. Note that R ₁ to R ₄ are resistances.

The operation of the present invention having the above configuration will be briefly explained.

(i) When no lens is attached to the camera body.

When the lens is not attached, the contact seat 10 on the lens side is separated from the contact seat 3 on the camera body side, so the contacts 3a ₁ to 3a ₇ and 10a ₁ to 10 on the lens side are separated from each other.
A and ₇ are not in contact with each other. Further, as shown in the figure, the lens mounting detection switch 26 provided on the camera side bayonet mount 1 has two switch pieces separated from each other. Therefore, the input terminal of the electronic circuit 21 is connected to the power supply 2 via the pressure reducing resistor RPD.
2, and a low level voltage close to the ground voltage is applied to the input terminal. Therefore, the analog switch 24 is turned off (open state) from the output terminal of the electronic circuit 21.
Since a high level voltage is generated, the analog switch 24 is turned off, and the power supply 22 and the contact pin _3a1 are cut off.

(ii) When a lens is attached to the camera body.

When attaching a lens to the camera body, the lens side bayonet mount 8 is rotated clockwise in the figure with respect to the camera side bayonet mount 1. is rotated counterclockwise about its pivot point, and as a result, one switch piece of the lens attachment detection switch 26 is pushed by one arm of the lens attachment/detachment responsive member 27. , both switch pieces of the detection switch 26 come into contact with each other, and the switch 26 is turned on. Therefore, the 5V output terminal of the constant voltage output circuit 23 is connected to the input terminal of the electronic circuit 21 via the switch 26, so that a high level (5 volts) input voltage is applied to the input terminal. For this reason,
The voltage level of the output terminal of the electronic circuit 21 is changed from "H" to "L", the analog switch 24 is turned on, and the positive electrode of the power supply 22 and the contact pin _3a1 are connected.

On the other hand, the lens is mounted on the camera side bayonet mount 1.
When the camera is fully attached, contact pin 3a ₁ on the camera side
~ 3a ₇ is in contact with the contacts 10a ₁ ~ 10a ₇ on the lens side as shown in the figure, so the wiring on the camera body side
L ₁ to _{L 7} are contacts 3a ₁ to 3 to the wiring L ₈ to L ₁₄ on the lens side.
a ₇ , 10a ₁ to 10a ₇ , and as a result, the wiring connection as shown is completed. (however,
In the attached drawing, lens attachment detection switch 2
Although the switch 26 is shown in an open state, the switch 26 remains in a closed state when the lens attachment is completed. ) After the lens attachment is completed, control signals related to camera operations (mainly focusing operations) are sent from the electronic circuit ₂₁ on the camera body side to the electronic circuit 30 on the lens side via the wiring L ₄ to _{L 6} and L 11 to L ₁₃ . At the same time, a signal related to the motor 29 is sent from the electronic circuit 30 on the lens side to the electronic circuit 21 on the camera side via the same wiring. For example, in response to a control signal from the electronic circuit 21, the electronic circuit 30 changes the signal level of the wiring _M1 (the topmost signal related to motor control) to "L", and at the same time, the wiring _M3 (the third signal from the top) ) is set to "H", transistors T ₁ and T ₃ become conductive, and current flows into the motor 29 in the direction of arrow b in the figure through the wiring L ₈ and the transistor T ₁ , and the motor 29 starts running. The current is rotated in the normal rotation direction, and the current flows back to the negative electrode side of the power supply 22 through the transistor T ₃ , the wiring L ₉ , the contacts 10a ₂ and 3a ₂ , and the wiring L ₂ .

Further, when a signal to reverse the motor 29 is sent from the electronic circuit 21 to the electronic circuit 30 through the wirings L ₄ to _{L 6} , an "L" signal is sent from the electronic circuit 30 to the wiring M ₂ (second from the top). At the same time as the high level signal is output, an "H" level signal is output to the wiring _M4 (fourth from the top) (at this time, the signal level of the wiring _M1 is "H", and the signal level of the wiring _M3 is (The level is "L"), as a result, the transistors T ₂ and T ₄
becomes conductive, and a current flows into the motor 29 from the transistor _T2 in the direction opposite to the arrow b shown in the figure.
9 will be reversed.

Incidentally, when attaching the interchangeable lens B to the camera A by rotation, the lens side contacts 10a ₁ to 1 are connected as in the conventional example.
Foreign matter adhering to _0a7 is cleaned by the camera-side contact pins _3a7 to _3a1 sliding on the contacts (on the surface) during the mounting rotation described above. here,
There is a possibility that only the lens side contact 10a ₇ cannot be cleaned properly and foreign matter cannot be removed, but even if the contacts 10 ₇ and 3a ₇ become non-conductive due to the presence of foreign matter at the time of completion of installation. ,
The lens-side bayonet mount 8 and camera-side bayonet mount 1 are brought into pressure contact and electrically connected. Therefore, the wires L ₁₄ and L ₇ are electrically connected via the wires L _{14 ′} and L _{7 ′} , and the electric circuits of camera A and interchangeable lens B are reliably connected.

In addition, since the contact surfaces of the lens-side and camera-side bayonet mounts have a much wider area than the respective contact points, reliable conduction can be obtained through contact between both bayonet mounts. Further, since the two bayonet mounts are configured to come into complete contact with each other by a known mechanism when the rotation of the interchangeable lens is complete, malfunctions due to poor contact between the contacts can be completely prevented.

Next, based on FIGS. 4 to 6, the second embodiment of the present invention will be described.
An example will be explained. This second embodiment is a further improvement of the first embodiment, and is particularly aimed at suppressing wear on sliding contacts.
Components that are the same as those in the first embodiment are given the same reference numerals, and their explanations will be omitted. In FIGS. 5 and 6, the contact seat 3 on the camera A side has the first surface 3c and the second surface 3c.
A step surface deviated in the optical axis direction consisting of a surface 3c' is formed, and a cross-sectional surface consisting of a first surface 10c and a second surface 10c' is also formed on the contact seat 10 on the side of the interchangeable lens B. It should be noted that the amount of recess of the second surface 3c' of the contact seat 3 when viewed from the first surface 3c as a reference and the amount of depression of the contact seat 10
The amount of protrusion of the second surface 10c' when viewed from the first surface 10c is approximately the same as that of the second surface 10c'.

The first surface 3c of the contact seat 3 on the camera A side
Three camera side contact pins 3a ₁ , 33a ₂ and 3a ₂ ' are arranged on the second surface 3c', while the remaining camera side contact pins 3a ₃ to 3a ₇ are arranged on the second surface 3c'.
Further, the contact pins 3a ₁ , 3a ₂ , 3 are provided on the first surface 10c of the contact seat 10 on the side of the interchangeable lens B.
a ₂ ′ and three lens side contacts 10a ₁ , 10 corresponding to
a ₂ , 10a ₂ ', and the remaining lens side contacts 10a 3 to 10a ₇ corresponding to the contact pins _{3a 3} to 3a ₇ are arranged on the second surface 10c'. Here, the camera side contact pins 3a ₁ to 3a ₇ are urged in the optical axis direction by the contact springs 3b ₁ to 3b ₇ and are normally held in the protruding position, as in the first embodiment described above.
It can be retracted if pressed. Further, the lens side contacts 10a ₁ to 10a ₇ are fixedly arranged on the contact seat 10. However, the amount of constant protrusion of these contact pins 3a ₁ to 3a ₇ is determined by the amount that they are arranged on the second surface 3c' of the contact seat 3 when the interchangeable lens B is rotatably attached to the camera A, as shown in FIG. Camera side contact pin 3a ₃ ~ 3
The tip of a ₇ is the first surface 10 of the contact seat 10 on the lens side.
Lens side contacts 10a ₁ , 10a ₂ , 1 arranged at c
It is set to be out of contact with 0a ₂ '.

As shown in Figure 4, the wire _L7 ' connected in parallel to the wire _L7 is connected to the camera side bayonet mount 1.
Wiring L ₁₄ ′ connected in parallel to wiring L ₁₄ is connected to the lens side bayonet mount 8, respectively. Additionally, a wire connected in parallel to wire L ₂
L ₂ ′ is connected to the contact pin 3a ₂ ′, and a wiring L ₉ ′ connected in parallel to the wiring L ₉ is connected to the contact 10a ₂ ′.

To explain the operation of the second embodiment configured as above, the contact pin 3a ₂ ' is connected to the interchangeable lens B.
When the camera A is mounted and rotated, it slides on the two lens-side contacts 10A ₁ and 10a ₂ existing on the first surface 10c of the lens-side contact seat 10, causing foreign matter such as dust to adhere to the contact surface. Even if there is a problem, contact failure can be reliably prevented by cleaning (same as in the first embodiment described above). Also, contact pin 3
Similarly, a ₇ is the second part of the contact seat 10 when the mounting is rotated.
Lens side contact pins 10a ₃ to 1 present on surface 10c'
Similarly, contact failure can be reliably prevented by sliding and cleaning with _0a6 .
Note that if such mounting rotation is repeated, foreign matter may accumulate on the contacts _10a2 ' and _10a7 on the lens side, resulting in poor contact between them and the contact pins _3a'2 and _3a7 on the opposing camera side. However, when the installation is completed as described above, contact continuity is established between contact pins 3a ₂ and 10a ₂ and camera side bayonet mount 1 and lens side bayonet mount 8, so the connection between the camera and lens side electrical circuits is established. It will definitely be done.

In the second embodiment, the facing sides of both the contact seats 3 and 10 are stepped, so that when the interchangeable lens B is rotated to attach to and detach from the camera A, the contacts 3a ₁ to 3a ₇ , By reducing the number of sliding movements of each of 10a ₁ to 10a ₇ , wear on the contact pins can be reduced.

In the above embodiment, the contact pin on the camera side is movable, but the same effect can be obtained even if the contact pin on the lens side is movable.

As explained above, in the above-mentioned embodiment, the lens-side contact point and the lens-side bayonet mount, which are the rear part in the rotation direction in rotational mounting, are electrically connected in parallel. Even if a conduction failure occurs at the contacts due to adhesion of foreign matter such as dust, reliable electrical connection can be achieved by electrically connecting the mounts to each other.

Furthermore, in the embodiment, since the same line is electrically connected by substantially two systems of connection terminals, the reliability of the electrical connection can be further improved.

Further, in the embodiment, it is the ground line of the power supply that is electrically connected to the same line by two systems. Compared to other fine signal communication lines, the ground line has a stricter contact resistance tolerance between contacts, but in this example, the ground line is electrically connected in two ways. Therefore, it is necessary to make sure that no problems occur even if the lens side contact for the ground line is placed at the rear of the rotation direction in rotational mounting, and to widen the distance from the power supply line to avoid problems such as leaks. was completed.

In addition, in this example, by dividing the contact points on the lens side and the camera side into two sections by a step offset in the optical axis direction, it was possible to reduce the number of times the two contacts slide against each other and reduce the friction of the contact points. .

〔Effect of the invention〕

The present invention electrically connects in parallel the optical accessory-side electrical connection terminal and the optical accessory-side mount, which is the rear part in the rotational direction when the camera body is rotatably mounted, to provide electrical connection in two systems. To provide an optical accessory that can greatly improve reliability by making it possible.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention, and FIG. 1 is an electrical circuit diagram showing an outline of the electrical connection when the interchangeable lens and camera are combined;
Figure 2 is a sectional view showing the state of the connector during rotation when attaching the interchangeable lens to the camera body, Figure 3 is a sectional view showing the completed attachment state, and Figures 4 to 6 are the main body. This shows a second embodiment of the invention, and FIG. 4 is an electric circuit diagram showing an outline of the electrical connection when the interchangeable lens and camera body are combined, and FIG. FIG. 6 is a cross-sectional view showing the state of the connector in the middle of installation, FIG. 6 is a cross-sectional view showing the state of completion of installation, and FIGS. 8 is a front view of the camera-side bayonet mount viewed from the front side, and FIG. 9 is a front view of the lens-side bayonet mount viewed from the mounting side. Figure 10 is a sectional view showing the state of the connector during rotation when attaching the interchangeable lens to the camera body;
FIG. 1 is a sectional view showing a state in which the mounting is completed. A...Camera, B...Interchangeable lens (optical accessory),
1...Camera side bayonet mount, 3...Contact seat,
3a ₁ to 3a ₈ ...Camera side contact pin, 8...Lens side bayonet mount, 10...Contact seat, 10a ₁ to 10
a ₇ …Lens side contact.

Claims (1)

[Scope of Claims] 1. A group of electrical connection terminals on the optical accessory side that slides with a group of electrical connection terminals on the camera body side by rotation for attaching the mount on the optical accessory side to the mount on the camera body side. In the optical accessory equipped with the above-mentioned optical accessory, when the accessory-side mount is rotationally attached to the camera body-side mount, an electrical connection terminal in the optical accessory-side electrical connection terminal group that is a rear part in the rotation direction and The optical accessory side mounts are electrically connected in parallel to enable parallel electrical connection between a corresponding electrical connection terminal in the camera body side electrical connection terminal group and the camera body side mount. Optical accessories characterized by: 2. By rotating the optical accessory side mount to attach it to the camera body side mount, the first optical accessory side electrical connection terminal group that slides with the first camera body side electrical connection terminal group is attached. and the first
An optical device comprising a second optical accessory side electrical connection terminal group that slides with a second camera body side electrical connection terminal group that is arranged offset from the camera body side electrical connection terminal group in the optical axis direction. In the accessory, when the accessory mount is rotatably attached to the camera body mount, at least one of the electrical connection terminals in the group of electrical connection terminals on the optical accessory side is connected to the rear part in the rotation direction. The optical accessory side mounts are electrically connected in parallel, and a corresponding electrical connection terminal in at least one of the camera body side electrical connection terminal groups is electrically connected in parallel with the camera body side mount. An optical accessory characterized by making it possible.