JPH0448375B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical accessory that can be attached to a camera body.

<Prior Art> In an interchangeable lens camera using a rotary detachable bayonet mount, the mounts of the interchangeable lens and the camera body are coupled or detached by rotating clockwise or counterclockwise. Recently, the interchangeable lens side and the camera body side each have electric circuits, and various information such as information for automatic exposure control and information for automatic focus adjustment has been exchanged between them. For this reason, it has become known that a large number of connector pin configurations are provided near the mount.

That is, as shown in FIGS. 8 to 11, a camera side bayonet mount 1, a lock pin 2 for fixing when the lens side mount is attached, and a camera side connector are formed on the front surface of the camera body 4 of camera A (FIG. 4). A contact seat 3 is fixedly mounted on the contact seat 3, and a contact pin 3a consisting of a plurality of contact pins 3a ₁ to 3a ₇ (seven in the illustrated example) is connected to a contact spring 3b ₁ to 3, respectively.
The contact spring 3b consisting of b ₇ urges the contact pins 3a 1 to _3a to protrude at the same height from the front surface of the contact seat 3.
_3a7 is connected to the camera body side electric device 6 by a flexible printed board 5. On the other hand, the interchangeable lens B holds the photographing lens group 7, and has a lens-side bayonet mount 8 on its rear end surface, an elongated lock groove 9 that engages with the lock pin 2 on the camera side, and a contact seat that constitutes a lens-side connector. 10 is fixedly installed, and the contact seat 10 has a contact pin 10a consisting of a plurality of contact pins 10a ₁ to 10a ₇ (seven in the illustrated example).
are fixed so that their rear ends are flush with each other,
The contact pins 10a ₁ to 10a ₇ are 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.
In contrast, the lens _- side bayonet mount 8 has three claws 8a ₁ to 8a ₃ that engage with the claws 1a ₁ to 1a _{3 ,} respectively. . When the mounting is completed, the locking pin 2 on the camera side engages with the locking groove 9 to maintain the mounted state.

When the interchangeable lens B is attached to the camera A with each bayonet mount, the mount surfaces of both lenses overlap each other as shown in FIG. 4, and the lens side contact pin 10a is attached to the camera body side contact pin 3a. 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 pin 10a ₁ to 10a ₇ are electrically connected, respectively, and the camera body side electric device 6 and the lens side electric The devices 12 exchange electrical signals with each other.

Regarding the connection operation of both contact pins when the interchangeable lens B is attached, as shown in FIG. Contact pins 3a ₇ to 3a ₁ of seat 3 are sequentially connected to lens side contact seat 1.
Contact springs 3b ₇ to 3b ₁ pushed by the end slope 10b of 0
In the compressed state, the contact pins 3a 1 and 10a 1 are alternately pressed and slid onto the surface of the lens side contact seat 10 and the lens side contact pins 10a ₁ to 10a ₇ , and when the attachment is completed, the contact pins 3a ₁ and 10a ₁ are compressed as shown in FIG. ,3a ₂ and 10a ₂ ,...3a ₇ and 1
0a and ₇ are in contact with each other on the same plane.

<Problems to be Solved by the Invention> However, in the conventional connection connector as shown in FIGS. 8 and 9, each time the interchangeable lens B is rotated and attached to the camera A, the lens side contact pin 10a ₁ first comes into sliding contact with the camera side contact pin 3a ₇ , and then comes into sliding contact with the camera side contact pins 3a ₆ to 3a ₁ to complete the rotational mounting. Hereinafter, during rotational mounting, the lens side contact pin _10a2 comes into sliding contact with the camera side contact pins _3a7 to _3a2 , the lens side contact pin _10a3 comes into sliding contact with the camera side contact pins _3a7 to _3a3 , and...the lens Side contact pin 10
a ₆ is in sliding contact with the camera side contact pins 3a ₇ and 3a ₆ , and the lens side contact pin 10a ₇ is in sliding contact with the camera side contact pin 3
Sliding contact only with a ₇ .

The lens-side contact pins 10a ₁ to 10a ₇ are fixed, and are disposed at the same height as the connection surface of the lens-side contact seat 10 or in a recessed state, so that foreign substances such as dust and dirt may not be present. The degree of adhesion is high. In the conventional connection connector described above, the lens side contact pins 10a ₁ to 10a ₇
Foreign matter adhering to the camera is cleaned by sliding the camera-side contact pins 3a ₇ to 3a ₁ on the pins (on the surface) during the mounting rotation described above. Here, the lens side contact pins 10a ₁ to 10a ₆ and the camera side contact pins 3a ₇ to 3a ₁ slide from end to end (left and right ends in FIGS. 8 and 9) at least once. However, only the lens side contact pin 10a ₇ is cleaned when the camera side contact pin 3a ₇ is moved from one end (the right end in FIGS. 8 and 9) to approximately the center when the rotation is completed. Because it only slides up to the
Reliable cleaning may not be performed and foreign matter may not be removed. Also, interchangeable lens B
Every time the camera A is rotated and attached to the camera A, foreign matter attached to the lens side contact pins 10a ₁ to 10a ₆ is removed by the camera side contact pins 3a ₇ to 3a ₂ in the direction of the lens side contact pin 10a ₇ . The foreign matter is transported and accumulated on the lens-side contact pin _10a7 , and the degree of foreign matter adhering to the lens-side contact pin _10a7 increases.This foreign matter causes poor contact, etc., and damages the camera and lens. There was a problem that normal operation of the system could not be guaranteed.

<Purpose of the Invention> The present invention has been made to solve the above-mentioned problems of the conventional art. To provide an optical accessory that can improve continuity reliability and prevent malfunctions by connecting accessory-side connection terminals in parallel with each other in a small number of times.

<Means for achieving the object> An optical accessory that has an accessory-side bayonet mount and is attached to the camera body by relative rotation with the camera-side bayonet mount of the camera body, wherein the camera body A first accessory-side connection terminal group is provided that slides with the first camera-side connection terminal group of the camera body during relative rotation for attachment to the camera body, and among the first accessory-side connection terminal group, Said first
Connect electrically in parallel the connection terminal with the least number of sliding movements when attached to the camera-side connection terminal group and the connection terminal with the second least number of sliding movements, and connect with the two connection terminals. The present invention is characterized by an optical accessory that receives or supplies a common signal to and from connection terminals in the first camera-side connection terminal group.

<Example> A first example of the present invention will be described below with reference to FIGS. 1 to 4.

A rotatable camera-side bayonet mount 1 of the camera body 4 on the front side of the camera A shown in FIG.
A contact seat 3 constituting a camera body side connector is provided around the circumferential area, and camera side contact pins 3a ₁ , 3a ₂ , . . . , 3a ₈ are arranged on the contact seat 3 at equal intervals along the circumferential direction. , and contact springs 3b ₁ to 3b ₂ ,..., 3b ₈
The front surface of the contact seat 3 (FIGS. 1 and 2)
In the figure, the contact pins 3a ₁ to 3a ₈ protrude from the top surface of the flexible printed board 5.
It is connected to a power supply battery (not shown) whose terminals are connected to the camera body side electric device 6 and a power supply pattern (not shown) of the flexible printed board 5.

On the other hand, lens-side contact seats 10 constituting an interchangeable lens-side connector are provided around the rotatable lens-side bayonet mount 8 of the interchangeable lens B, and the contact seats 10 are arranged at equal intervals along the circumferential direction. Lens-side contact pins 10a ₁ , 10a ₂ , . . . , 10a ₈ are fixedly attached to the lenses.

Furthermore, the camera side contact pins 3a ₇ and 3a ₈ and the lens side contact pins 10a ₇ and 10a ₈ are electrically connected in parallel, which will be explained later using the electrical circuit diagram shown in FIG. do. Slopes 10b ₁ and 10b ₂ are formed on the outer end surfaces of the contact pins 10a ₁ and 10a ₈ of the lens side contact seat 10, respectively, and when the interchangeable lens B is rotatably attached to the camera A, the contact pins 3a 1 to 3a ₁ on the camera A side are formed. The lens contact pins 10a _{1 to} 10a ₈ are connected to the lens-side electric device 12 via a flexible printed board _{11 .} There is.

It is located at the same diameter position as the camera-side contact pins 3a ₁ to 3a ₇ of the contact seat 3 of the camera A, and when the interchangeable lens B is mounted and rotated, the lens-side electrical contact pin 1
A contact pin 3a ₈ having a cleaning function is provided in the circumferential direction in the direction of first connection to 0a so as to be movable in the optical axis direction. This contact pin 3a ₈ is connected to the other camera side contact pin 3a ₁ by a spring member 3b ₈ .
~3a ₇ is biased in the same direction and approximately at the same protrusion height.

With the above arrangement and configuration, the contact pin _3a8 slides with all the lens-side contact pins _{10a1 to 10a7 when the interchangeable lens B is rotated to be attached to the camera A, and when the attachment is completed, the contact pin 3a8 slides on all the lens-side contact pins 10a1} to _10a7 , as shown in FIG. As shown in FIG. 2, the lens reaches a position where it abuts against the lens side contact pin _10a8 . Therefore, lens side contact pin 1
Even if foreign matter such as dust adheres to the contact surfaces of 0a ₁ to 10a ₇ , the foreign matter should be cleaned by sliding (swept away like a wiper) during the above-mentioned mounting rotation. The lens side contact pin _10a7 , which is essentially on the negative end side, which was impossible to clean, can also be cleaned by sliding, and the lens side contact pins _10a1 to _10a7 and the camera side contact pins _3a1 to 3 can be cleaned by sliding.
Electrical contact can be ensured at the stage of completion of installation with _A7 .

As mentioned above, the camera side contact pin _3a8 removes foreign matter such as dirt and dust from the contact portions of the lens side contact pins _10a1 to _10a7 , and the lens side bayonet mount 8 is removed from the camera side bayonet mount 1. In the state shown in Fig. 2 when the attachment is complete, the lens side contact pins _10a1 to _10a7 and the camera side contact pin _3a1
3a and ₇ are in contact with each other, dirt and dust between the contacts is removed, and contact failures are greatly reduced due to increased contact resistance.

Furthermore, as mentioned above, the camera-side contact pins 3a ₇ and 3a ₈ and the lens-side contact pins 10a ₇ and 10a ₈ are electrically connected in parallel, and in order to establish continuity between each two contact portions, Poor contact accidents are reduced.

FIG. 3 is an electric circuit diagram showing the connection between the camera body side electric device 6 and the lens side electric device 12 used in the present invention.

In the figure, 21 is an electric circuit mounted on the camera body, 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 also connects the electronic circuit 21 and the lens side described later. A constant voltage output circuit serves as a power source for the electronic circuit, 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 a camera side bayonet mount provided on the camera body, and 26 is a A lens mounting detection switch 27 is provided on the input signal line of the electronic circuit 21 and is located near the camera-side bayonet mount 1. Reference numeral 27 is a lens mounting/detaching response member that operates 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, and one arm is driven by engaging a part of the lens side bayonet mount 8. , the other arm is a lens attachment detection switch 26.
The switch piece on one side is pressed.

The lens attachment 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 contact pins 10a ₁ to 10a ₇ provided on the lens side. A large number of contact pins 3a 1 to 3a 7 are provided, each contacting the contact pins 3a ₁ to 3a ₇ . Here, the contact pins 3a ₁ to 3a ₇ are individually connected to the wiring L ₁ to L ₇ on the printed wiring board attached to the camera body, but the contact pin 3a ₈ having a cleaning function is connected to the wiring L ₁ It can be seen that it is connected in parallel to one wiring L ₇ of ~L ₇ . Similarly, the contact pin _10a8 is connected in parallel to the wiring _L14 .

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 are provided.

The wiring L ₃ connected to the contact pin 3 a ₃ is connected to the lens attachment detection switch 26 and the input terminal of the electronic circuit 21 . Also, the wire L ₂ connected to contact pin 3a ₂ is a power ground line (power ground line)
The wiring L ₂ is connected to the negative electrode of the power supply 22.

The wire 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 wire L ₇ is connected to the ground terminal of the electronic circuit 21 on the camera body side as well as the power source 22. 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.

The interchangeable lens of the present invention, which is configured to be detachably attached to the camera body configured as described above, includes a focusing drive motor 29, a stationary switch device that switches the direction of power supply to the motor 29, and The lens is equipped with an electronic circuit 30 that controls the motor 29 and exchanges various signals with the electronic circuit 21 on the camera body side, and is detachably fitted to the camera side bayonet mount 1. A side bayonet mount 8 and a contact seat 10 which is disposed in a lower inner peripheral area of the lens side bayonet mount 8 and faces the contact seat 3 on the camera body side are 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.
7 contact pins 10a ₁ to 10a ₇ that can contact 3a ₇
These contact pins 10a ₁ ~
Wiring lines _L8 to _L14 are connected to _10a7 , respectively.

The wires _L8 and _L9 are connected to the motor 29 via a static switch device, which will be explained later, and serve as power lines for flowing a larger current than the other wires _L10 to _L14 , which will be explained later. As shown, _L8 is a motor power line, and _L9 is a power ground line for grounding one pole of the motor 29.

The wiring L ₁₀ connected to the contact pin 10a ₃ serves as an electronic circuit power 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 contact pin 10a _3. and _3a3 , it is connected to the wiring _L3 on the camera body side.

The wiring L ₁₄ is connected to the ground terminal of the electronic circuit 30 and to the wiring L ₇ on the camera body side via contact pins 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 connected to the contact pins 10a ₄ to 10a ₆ respectively, and are also connected to the contact pins 10a ₄ to 10a ₆ on the lens side and the camera body side. contact pin 3
Wiring L ₄ to L ₆ on the camera body side via a ₄ to 3a ₆
They are each connected separately. That is, the wirings L ₁₁ to _{L 13} are signal lines on the lens side.

The static switch device for switching the direction of power supply to the motor 29 consists of one NPN transistor.
It consists of two sets of four transistors T ₁ to T ₄ paired with a PNP transistor, 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. In addition, the emitters of each pair 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 pin 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 . Wiring _L9 is a power ground line provided on the interchangeable lens side, and connects the negative pole side of the motor 29 to contact pin 1.
It is connected to the contact pin 3a ₂ on the camera body side via 0a ₂ and to the negative electrode of the power source 22 via the wiring L ₂ on the camera body side.

The electronic circuit 30 is provided with a control terminal for controlling each transistor T ₁ to _{T 4} of the static switch device, and each control terminal and each transistor T _{1 to} T 4 are connected to each other.
Each base of T ₄ is connected to signal lines M ₁ to M ₄ . Note that R ₁ to R ₄ are resistances.

As mentioned above, the feature of the interchangeable lens of this embodiment is that the grounding wire and grounding connection terminal of the motor 29 and the grounding wire and grounding connection terminal for the electronic circuit are respectively provided for exclusive use. The operation of the illustrated components will be briefly explained below.

() 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 both contact pins 3a ₁ to 3a ₇ and 10a ₁ to
10a 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 negative electrode of the power supply 22 via the pressure reducing resistor RPD, and a low level voltage close to the ground voltage is applied to the input terminal. Therefore, a high level voltage is generated from the output terminal of the electronic circuit 21 that turns off the analog switch 24 (open state), so the analog switch 24 is turned off and the power supply 2 is turned off.
2 and contact pin _3a1 are disconnected.

() 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 are in contact with the contact pins 10a ₁ ~ 10a ₇ on the lens side as shown in the figure, so the wiring L ₁ ~ L ₇ on the camera body side is connected to the wiring L ₈ ~ L ₁₄ on the lens side with the contact pins 3a ₁ ~ Connected via 3a ₇ , 10a ₁ to 10a ₇ ,
As a result, wiring connections as shown are completed.
(However, in the attached drawing, the lens attachment detection switch 26 is shown in an open state, but when the lens attachment is completed, the switch 26 is kept in the closed state.) After the lens attachment is completed, the camera body Control signals related to camera operations (mainly focusing operations) are sent from the electronic circuit 21 on the lens 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, the electronic circuit 30 on the lens side From there, signals related to the motor 29 are sent to the electronic circuit 21 on the camera side via the same wiring. For example, if the electronic circuit 30 changes the signal level of the wiring M ₁ to “L” and simultaneously changes the signal level of the wiring M ₃ to “H” in response to a control signal from the electronic circuit 21, the transistors T ₁ and
T ₃ becomes conductive, and a current flows into the motor 29 through the wiring L ₈ and the transistor T ₁ in the direction of the arrow b shown in the figure, causing the motor 29 to rotate in the forward rotation direction, and the current flows through the wiring through the transistor T ₃ L ₉ , contact pin 10a ₂
And 3a ₂ , the current flows back to the negative electrode side of the power supply 22 through the wiring L ₂ .

Furthermore, when a signal to reverse the motor 29 is sent from the electronic circuit 21 to the electronic circuit 30 through the wiring L ₄ to _{L 6} , an “L” signal is sent from the electronic circuit 30 to the wiring M ₂ .
At the same time as the high level signal is output, an "H" level signal is output to the wire _M4 (at this time, the signal level of the wire _M1 is "H", and the signal level of the wire _M3 is "L"). ), and as a result, the transistor
T ₂ and T ₄ are conductive and the motor 29 is connected to the arrow b shown in the figure.
A current in the opposite direction flows from the transistor _T2 , causing the motor 29 to rotate in reverse.

Next, based on FIGS. 5 to 7, 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 the wear of the sliding contact pin, and the same components as the first embodiment are the same. A reference numeral is given and the explanation thereof will be omitted. 5 and 6, the contact seat 3 on the camera A side is formed with a stepped surface consisting of a first surface 3c and a second surface 3c', while the contact seat 10 on the interchangeable lens B side also has a first surface 10c. and second
A step surface consisting of surface 10c' is formed. Furthermore, the amount of depression of the second surface 3c' when viewed from the first surface 3c of the contact seat 3 as a reference, and the amount of protrusion of the second surface 10c' when viewed from the first surface 10c of the contact seat 10 as a reference. They almost match.

The first surface 3c of the contact seat 3 on the camera A side
Two camera-side contact pins 3a ₁ and 3a ₂ are provided on the second surface 3c', while the remaining camera-side contact pins 3a ₃ to 3a ₇ are provided on the second surface 3c'. Further, two lens-side contact pins 10a 1 and 10a ₂ corresponding to the above-mentioned contact pins 3a ₁ and 3a ₂ are arranged on the first surface 10c of the contact seat ₁₀ on the side of the interchangeable lens B, and on the other hand,
The remaining lens-side contact pins 10a ₃ to 10a ₇ corresponding to the above-mentioned contact pins 3a ₃ to 3a ₇ are arranged on the second surface 10c'. Here, the camera side contact pin 3a ₁ ~
3a ₇ are contact springs 3b ₁ to 3b as in the first embodiment described above.
_3b7 , it is urged in the optical axis direction and is normally held in the protruding position, and of course can be retracted when pressed. Further, the lens side contact pins 10a ₁ to 10a ₇ are fixedly disposed on the contact seat 10. However, the amount of constant protrusion of these contact pins 3a ₁ to 3a ₇ is
As shown in the figure, when attaching the interchangeable lens B to the camera A, the tips of the camera-side contact pins 3a ₃ to 3a ₇ arranged on the second surface 3c' of the contact seat 3 are attached to the contact seat on the lens side. The lens side contact pins 10a ₁ and 10a ₂ disposed on the first surface 10c of the lens 10 are set so as not to be in contact with each other.

On the other hand, a contact pin 3a ₉ having a cleaning function is arranged on the first surface 3c of the contact seat 3 on the camera side, and a contact pin 3a ₁₀ , which also has a cleaning function, is arranged on the second surface 3c'. . This contact pin 3a ₉ is located at the same diameter position as the camera side contact pins 3a ₁ and 3a ₂ , and is provided at a position in the circumferential direction where it first slides with the lens side contact pin 10a ₁ when rotating the interchangeable lens B. The spring member _3b9 is biased to protrude and retract in the optical axis direction. Further, the contact pin 3a ₁₀ is at the same diameter position as the camera side contact pins 3a ₃ to 3a ₇ , and is at the circumferential position where it first slides with the lens side contact pins 10a ₃ to 10a ₇ when the interchangeable lens B is rotated. Spring member 3
b ₁₀ , it is urged to protrude in the optical axis direction so as to be retractable. Note that the always protruding height of the contact pin 3a ₉ is set to be approximately the same height as the camera side contact pins 3a ₁ and 3a ₂ , and the normally protruding height of the above contact pin 3a ₁₀ is set to the same height as the camera side contact pin 3a _3. It is set at almost the same height as ~ _3a7 . Further, on the first surface 10c of the contact seat 10 on the side of the interchangeable lens, there is a contact pin 10a ₉ that comes into contact with the contact pin 3a ₉ in the fully attached state shown in FIG.
However, similarly, the contact pin 3a ₁₀ is on the second surface 10c'.
Contact pins 10a _{and 10} that come into contact with are respectively arranged. In addition, as shown in FIG. 7, the contact pin 3a ₉ on the camera side is connected to the wiring L ₂ connected to the contact pin 3a _2.
In addition, the contact pin 3a ₁₀ is connected in parallel to the wiring L ₇ connected to the contact pin 3a ₇ . On the other hand, the contact pin 10a ₉ on the interchangeable lens side is connected to the wiring L ₉ connected to the contact pin 10a ₂ , and the contact pin 10a ₁₀ is connected to the contact pin 1.
It is connected in parallel to the wiring _L14 connected to _0a7 .

To explain the operation of the second embodiment configured as described above, when the interchangeable lens B is rotated to attach to the camera A, the contact pin _3a9 connects the two lenses present on the first surface 10c of the contact seat 10 on the lens side. Even if foreign matter such as dust adheres to the contact surface by sliding on the side contact pins 10a ₁ and 10a ₂ , cleaning (same as in the first embodiment) will reliably prevent poor contact. Also, when the contact pin 3a ₁₀ is mounted and rotated, the second surface 1 of the contact seat 10
The remaining five lens side contact pins 1 present at 0c'
By sliding and cleaning 0a ₃ to 10a ₇ , poor contact can be similarly prevented reliably.

In the second embodiment, since the facing sides of both contact seats 3 and 10 are stepped, both contact pins 3a ₁ to 3a ₇ , 10a ₁ to 10a ₇
By reducing the number of sliding movements of each contact point, wear of the contacts can be reduced. For example, when the lens-side contact pin 10a ₁ in the first embodiment is rotated, it slides with the seven camera-side contact pins 3a ₁ to 3a ₇ and the contact pin 3a ₈ having a cleaning function. In the second embodiment, there are a total of three contact pins (3 contact pins).
a ₁ , 3a ₂ and contact pin 3a ₉ ), and the number of times the other contact pins slide can be reduced to suppress wear.

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

What is characteristic about the above-described embodiment is that when the interchangeable lens B as an optical accessory is rotatably attached to the camera A, the lens side contact pin (No. In the first embodiment, the contact pin 10a ₈ and in the second embodiment, the contact pin 10
a ₁₀ and 10a ₉ ) and the second smallest lens side contact pin (contact pin 10a ₇ in the first embodiment, contact pins 10a ₇ and 10a ₂ in the second embodiment) are electrically connected in parallel, and A common signal (ground signal) between two contact pins and the connected camera side contact pin.
Therefore, even if the contact pin on the lens side, which slides the least number of times, has poor conduction due to foreign matter such as dust, no problem will occur because proper conduction can be achieved using the other contact pin. Furthermore, since the two contact pins, which have a small number of sliding movements, are electrically connected in parallel, no problem will occur as long as at least one of the contact pins can conduct, and reliability can be significantly improved.

In the above embodiment, the number of contact pins on the lens side is basically increased by one pin compared to the conventional one, and the same signal is received or supplied from two contact pins by parallel connection, so the contact pin group on the camera side and the contact pin on the lens side are connected in parallel. The total number of sliding movements with the group increases accordingly. In the second embodiment, both contact pin groups are further divided into steps in the optical axis direction in order to reduce the total number of sliding movements and improve the reliability of the above-mentioned conduction.

<Effects of the Invention> The present invention provides an accessory-side connection terminal that slides the least number of times with the camera-side connection terminal group and an accessory-side connection terminal that slides the second least number of times during relative rotation for attachment to the camera body. are electrically connected in parallel and a common signal is received or supplied between these two connection terminals and the connected camera side connection terminal, so the accessory side connection terminal has fewer sliding movements. It is possible to solve the problem of poor conduction in the device, and to provide an optical accessory with significantly improved reliability.

In addition, in the second invention, the camera-side connection terminal group and the accessory-side connection terminal group are further shifted in the optical axis direction and divided into at least two groups, thereby reducing the total number of sliding movements of both connection terminal groups. It is possible to provide an optical accessory in which wear due to sliding of the connecting terminal is reduced.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the state of the connector while an accessory device is being attached to the main body of the optical device, and FIG.
The figure is a sectional view showing a state in which the connector shown in Fig. 1 has been attached, and Fig. 3 is an electric circuit diagram showing an outline of the electrical connection when the interchangeable lens and camera are connected.
Fig. 4 is a vertical cross-sectional view of the central part of the camera with the lens attached, Figs. FIG. 6 is a cross-sectional view showing the state of the connector shown in FIG. 5, and FIG. 7 is an electrical circuit schematically showing the electrical connection when the interchangeable lens and camera are connected. 8 to 11 show a second embodiment of the present invention, in which FIG. 8 is a sectional view showing the state of the connector in the middle of attaching an accessory to the optical equipment main body, and FIG. 10 and 11 are cross-sectional views showing the completed state of the connector shown in the figure, and show conventional examples.
The figure is a front view of the lens-side bayonet mount viewed from the mounting side. A...Camera (optical equipment), B...Interchangeable lens (attached equipment), 1...Camera side bayonet mount, 3...Contact seat, 3a ₁ to 3a ₁₀ ...Camera side contact pin, 8...Lens Side bayonet mount, 1
0... Contact seat, 10a ₁ to 10a ₁₀ ... Lens side contact pin.

Claims (1)

[Scope of Claims] 1. An optical accessory that has an accessory-side bayonet mount and is attached to the camera body by relative rotation of the camera body with the camera-side bayonet mount, comprising: A first accessory-side connection terminal group is provided that slides with the first camera-side connection terminal group of the camera body during relative rotation for mounting, and the first accessory-side connection terminal group is provided with the first accessory-side connection terminal group. 1st
Connect electrically in parallel the connection terminal with the least number of sliding movements when attached to the camera-side connection terminal group and the connection terminal with the second least number of sliding movements, and connect with the two connection terminals. An optical accessory that receives or supplies a common signal with a connection terminal in the first camera-side connection terminal group. 2. An optical accessory that has an accessory-side bayonet mount and is attached to the camera body by relative rotation with the camera-side bayonet mount of the camera body, the relative rotation for attachment to the camera body. At times, a first accessory side connection terminal group is provided that slides with the first camera side connection terminal group of the camera body, and when the camera body is rotated relative to the first camera side connection terminal group for attachment, the first camera side connection terminal is connected to the first camera side connection terminal group. The terminal group is a second accessory-side connection terminal group that slides with a second camera-side connection terminal group of the camera body that is shifted in the optical axis direction, and is included in the first accessory-side connection terminal group. In the first
Connect electrically in parallel the connection terminal that slides the least number of times when attached to the camera-side connection terminal group and the connection terminal that slides the second least number of times, and connect the two connection terminals. An optical accessory that receives or supplies a common signal with a connection terminal in the first camera-side connection terminal group.