GB2249186A

GB2249186A - Interchangeable lens camera

Info

Publication number: GB2249186A
Application number: GB9120498A
Authority: GB
Inventors: Tatsuhide Takebayashi
Original assignee: Asahi Kogaku Kogyo Co Ltd
Current assignee: Pentax Corp
Priority date: 1990-10-03
Filing date: 1991-09-26
Publication date: 1992-04-29
Also published as: FR2667700A1; GB9120498D0; DE4132860A1

Abstract

An interchangeable lens camera includes a camera body (10) which has a power source and electric contacts (16) connected to the power source, an interchangeable lens (20) which is detachably attached to the camera body (10) and which has electric contacts (26) which come into contact with the corresponding electric contacts (16) of the camera body (10) to supply the interchangeable lens (20) with power from the power source and to transmit and received electrical signals to and from the camera body (10) when the interchangeable lens (20) is attached to the camera body (10). The camera also includes a lens attachment and detachment member (13) which is actuated when the interchangeable lens (20) is attached and detached to and from the camera body (10), and a switch member (36) associated with the lens attachment and detachment member (13) which is activated under a predetermined condition to prohibit power supply and signal communication between the interchangeable lens (20) and the camera body (10) only after a predetermined amount of time. <IMAGE>

Description

f 2 24 91 3 o INTERCHANGEABLE LENS CAMERA The present invention relates to

an interchangeable lens camera, and more precisely, it relates to an interchangeable lens camera in which a camera body and an interchangeable lens have respective electric contacts which come into electrical contact with each other when the interchangeable lens is attached to the camera body.

Recently, there have been cameras having various electronic circuits and motors incorporated therein to automate or motorize various functions.

To realize an electronic or motor driven interchangeable lens camera, it is necessary to transmit and receive electrical signals from electronic circuits provided in the camera body to the electronic circuits provided in the interchangeable lens and vice versa. It is also necessary to supply the motor provided in the interchangeable lens with electrical power from the power source provided in the camera body.

The power supply and signal communication which are usually required for automatic exposure, automatic focusing, or power zooming etc., are usually effected - 2 through electric contacts which come into contact with each other when the interchangeable lens is attached to the camera body.

However, in a known interchangeable lens camera having such electric contacts, when the interchangeable lens is detached from the camera body, if a photographer accidentally touches the operation members of a driving mechanism, such as the shutter button for performing the automatic focusing operation or a power zooming button, etc., the driving mechanism is actuated, much to the surprise of the photographer.

Such unexpected operation of the driving mechanism frequently occurs because (1) a photographer is usually concentrating on the detachment of the interchangeable lens from the camera body and therefore not paying attention to the operation members, (2) the operation members are positioned so as to be easily accessed, and (3) a relatively strong force is required to detach the interchangeable lens from the camera body, therefore one must firmly grip the camera, again resulting in a greater likelihood of accidental activation of the driving mechanism.

Furthermore, upon detachment of the interchangeable lens from -the camera body, if the operation members are actuated when the electrical connection between the electric contacts of the camera body and the interchangeable lens is not complete, a short or misoperation of the electronic circuits, including a microprocessor or the like, may take place.

These problems are more serious particularly in recent interchangeable lens cameras which require a higher electrical power than earlier interchangeable lens cameras.

In addition to the foregoing, in a known interchangeable lens camera having many electric contacts, if the photographer unconsciously touches the operation member of a driving mechanism such as the shutter button or the power zooming button, etc., while attaching the interchangeable lens to the camera body, the power supply to the motor of the corresponding driving mechanism commences as soon as the attachment of the lens to the camera body is completed, again, photographer.

contact interchangeable lens is wherein neither a driving circuits electrical electronic interchangeable startling the An object of the present invention is to provide an interchangeable. lens camera in which a camera body and an interchangeable lens have electric contacts which are brought into with each other when the attached to the camera body, unexpected operation of the nor misoperation of the camera takes place upon sudden mechanism of the - 4 detachment of the interchangeable lens from the camera body and atachment of the interchangeable lens to the camera body.

According to the present invention, there is provided an interchangeable lens camera including a camera body which has electric contacts, and an interchangeable lens which is detachably attached to the camera body and has electric contacts which come into electrical contact with the corresponding electric contacts of the camera body when the interchangeable lens is attached to the camera body, wherein said camera body employs a camera system having an outputting means to output electric signals to the interchangeable lens through the electric contacts of the camera body and the interchangeable lens, and wherein said camera body comprises; a locking means for securing the interchangeable lens to the camera body at a predetermined angular position with respect to the camera body; and, a switching means which permits the outputting means to output electric signals to the interchangeable lens only when the locking means is in an engagement position.

According to another aspect of the present invention, there is provided an interchangeable lens camera including a camera body which has a power source with electric contacts connected thereto and an interchangeable lens - 5 which is detachably attached to the camera body with electric contacts which come into contact with the corresponding electrical contacts of the camera body, wherein when the interchangeable lens is attached to the camera body, the electric contacts of each side come into contact, and the camera body side can then supply power to the interchangeable lens and electrical signals may be transmitted and received by both the camera body and interchangeable lens, and wherein the camera body further includes a lens attachment member (locking means) which is actuated when the interchangeable lens is attached to the camera body, a switching means which is associated with' the lens attachment member to selectively perform a first switching operation in which the power supply and the signal transmission or reception between the interchangeable lens and the camera body are prohibited, and a second switching operation associated with the completion of attachment of the interchangeable lens to the camera body, and a timer means for making possible the power supply and the signal transmission or reception between the interchangeable lens and the camera body through the electric contacts of the interchangeable lens and the camera body at a predetermined time after the completion of the second switching operation.

In a preferred embodiment of the invention, upon attachment of the interchangeable lens to the camera body, the lens attachment operation member is actuated before electrical power is supplied to the driving mechanisms and bef ore data communication between the electronic circuits or the electronic elements commences so that the switch associated with the lens attachment operation member carries out the f irst switching operation, whereby neither the power supply nor data communication can be effected.

In a preferred embodiment, when the interchangeable lens is attached to the camera body, the operation of the lens attachment operation member is completed and upon completion of the operation of the lens attachment operation member, the switch associated with the lens attachment operation member performs the second switching operation, whereby after the lapse of a predetermined time, the power supply or data communication can be effected.

Consequently, even if a photographer accidentally touches the automatic focusing button (switch) or the power zooming button (switch) upon attachment of the interchangeable lens to the camera body, neither an unexpected operation of the driving mechanisms nor misoperation of the electronic circuits, including the microprocessor or the like, occurs.

According to another aspect of the present invention, there is provided an interchangeable lens camera including a camera body which has a power source and electric contacts connected to the power source, an interchangeable lens which is detachably attached to the camera body with electric contacts which come into contact with the corresponding electric contacts of the camera body so as to supply the interchangeable lens with the power from the power source and to transmit and receive electrical signals to and from the camera body when the interchangeable lens is attached to the camera body, a lens detachment member which is actuated when the interchangeable lens is detached from the camera body, and a switch which is associated with the lens attachment member to stop the power supply and the signal transmission or reception between the interchangeable lens and the camera body through the electric contacts of the interchangeable lens and the camera body.

In a preferred embodiment, upon detachment of the interchangeable lens from the camera body, a lens detachment operation member is actuated and the switch associated with the lens detachment operation member is then actuated to intercept the power supply to the automatic focusing motor or the power zooming motor as well as the transmission of electrical signals to the control circuits thereof.

Consequently, even if a photographer accidentally touches the automatic focusing button (switch) or the power zooming button (switch) upon detachment of the interchangeable lens from the camera body or attachment of the interchangeable lens to the camera body, neither an unexpected operation of the driving mechanisms nor misoperation of the electronic circuits, including the microprocessor or the like, occurs.

Preferably, the switching means is constituted by a mount switch which is turned ON and OFF in accordance with the attachment and detachment of the interchangeable lens to and from the camera body.

According to a further aspect of the invention, there is provided an interchangeable lens camera including a camera body which has a power source and electric contacts connected to the power source, an interchangeable lens which is detachably attached to the camera body and which has electric contacts which come into contact with the corresponding electric contacts of the camera body to supply the interchangeable lens with power from the power source and to transmit and receive electric signals to and from the camera body when the interchangeable lens is attached to the camera body, a lens attachment member which is actuated when the interchangeable lens is attached to the camera body, a switching means associated with the lens attachment member which is actuated under a predetermined condition to perform a first switching operation in which the - 9 power supply and the signal transmission or reception between the interchangeable lens and the camera body are prohibited, and which is actuated to perform a second switching operation upon the completion of attachment of the interchangeable lens to the camera body; and, a timer means for making possible power supply and signal transmission or reception between the interchangeable lens and the camera body through the electric contacts of the interchangeable lens and the camera body after a predetermined time after the completion of the second switching operation.

The switching means is preferably constituted by a mount switch which is turned ON and OFF in accordance with the attachment and detachment of the interchangeable lens to and from the camera body.

According to a further aspect of the invention, there is provided an interchangeable lens camera including a camera body which has a power source and electric contacts connected to the power source, an interchangeable lens which is detachably attached to the camera body and which has electric contacts which come into contact with the corresponding electric contacts of the camera body to supply the interchangeable lens with power from the power source and to transmit and receive electrical signals to and from the camera body when the interchangeable lens is attached to the camera body, a lens detachment member which is actuated when the interchangeable - 10 lens is detached from the camera body, and a switching means associated with the lens attachment member to stop the power supply and signal transmission or reception between the interchangeable lens and the camera body through the electric contacts of the interchangeable lens and the camera body.

Examples of the present invention will be described below in detail with reference to the accompanying drawings, in which; Figure 1 is a front elevational view of an interchangeable lens camera body embodying the present invention; Fig. 2 is a side elevational view of an interchangeable lens of the interchangeable lens camera whose body is shown in Fig. 1; Fig. 3 is a back view of the interchangeable lens shown in Fig. 2; Fig. 4 is a schematic view of a lens attachment and detachment button, a mount switch, and a circuit, embodying the present invention; and, Fig. 5 is a view similar to Fig. 4 of another embodiment of the present invention.

power supply The embodiment illustrated in Figs. 1 through 4 is applied to a power zoom interchangeable lens camera.

In Fig. 1, a camera body 10 is provided on its front surface with a body mount 11 to which a lens mount 21 of an interchangeable lens 20 (Figs. 2 and 3) is detachably attached. The body mount 11 and the lens mount 21 are of bayonet type.

To attach the interchangeable lens 20 to the camera body 10, the lens mount 21 is aligned at some predetermined angular position with respect to the body mount 11 so as to be engaged therewith. The interchangeable lens 20 is then secured to the camera body 10 by rotation through a predetermined angular distance in a predetermined direction with respect to the camera body 10.

The body mount 11 is provided on its front surface with a retractable lock pin (locking means) 12 which is biased to project out from the front surface of the body mount 11 by a spring (not shown). The lock pin 12 is 12 connected to a lens attachment and detachment button 13 provided on the camera body 10 by a connecting piece 17 (Fig. 4).

Consequently, when the lens attachment and detachment button 13 is depressed to detach the interchangeable lens 20 from the camera body 10, the lock pin 12 is retracted into the body mount 11. On the other hand, upon attachment of the interchangeable lens to the camera body, when the lens mount 21 abuts against the front end (upper end) of the lock pin 12 to push it into the body mount 11, the lens attachment and detachment button 13 moves down and snaps back into position when the connection is complete.

As can be understood from the foregoing, since the lock pin 12 is depressed by the lens mount 21, upon attachment of the interchangeable lens to the camera body, the lens attachment and detachment button 13 is indirectly actuated (depressed) thereby. In the illustrated embodiment, the lock pin 12 and the lens attachment and detachment button 13 constitute a lens attachment and detachment member which is actuated when the interchangeable lens 20 is attached to the camera body 10.

The lens mount 21 has a lock pin hole 22 in which the lock pin 12 is fitted when the interchangeable lens 20 is attached to the camera body 10 in a photographable position. When the lock pin 12 is engaged in the lock pin hole 22, the - 13 interchangeable lens 20 is locked to the camera body 10.

For detachment of the interchangeable lens 20 from the camera body 10, the lens attachment and detachment button 13 is depressed to disengage the lock pin 12 from the lock pin hole 22 thereby releasing the lock. Thereafter, the interchangeable lens 20 is rotated to a detachment position in the direction opposite to the direction when the interchangeable lens i camera body thereby detaching the interchangeable lens 20 from the camera body 10.

The body mount 11 is provided on its front surface with a plurality of electric contacts 15 which come into contact with corresponding electric contacts 25 provided on the lens mount 21 to effect data communication and power supply therebetween when the interchangeable lens 20 is attached to the camera body 10.

The interchangeable lens 20 has a zooming mechanism (not shown) for moving the lens group thereof, which constitutes the interchangeable lens, a power zoom motor 31 (Fig. 4) for driving the zooming mechanism, a zoom ring 27 (Fig. 2) which constitutes a zoom operation member actuated by a photographer to effect the power zooming operation, a zoom operation switch 32 (Fig. 4) which selectively occupies a neutral position in which the zoom ring is not driven and a selection position when the zooming s attached to the - 14 mechanism is moved in either the wide angle direction or the telephoto direction in association with the zoom ring 27, and a lens control circuit 33 (Fig. 4) which controls the power supply to the zoom motor 31 in accordance with the selected position of the zoom operation switch 32 and the position of the zooming mechanism. The power zoom mechanism constituted by the components mentioned above is per se known, and accordingly, no detailed explanation thereof is given herein.

The interchangeable lens 20 has a pair of electric contacts 26 for power zooming, located inside the lens _mount 21. The power zooming electric contacts 26 are connected to the motor 31 through the lens control circuit 33.

The camera body 10 has a power source (not shown), f or example a battery, which is used as a power source not only for the power zooming operation of the interchangeable lens 20, but also for various devices in the camera body 10 such as an automatic exposure mechanism, an automatic film winding mechanism, etc. Fig. 4 shows a body control circuit 35 which is constituted by the power source and the surrounding circuits including the microprocessor etc.

The camera body 10 also has a pair of electric contacts 16 which are located inside the body mount 11 to come into contact with the associated electric contacts 26 1 - is - of the interchangeable lens 20 when the latter is attached to the camera body 10. The electric contacts 16 are connected to the body control circuit 35. In the illustrated embodiment, the body control circuit 35 and the lens control circuit 33 correspond to a control means for controlling the power supply to the motor 31 by the power source.

Thus, the power is supplied to the interchangeable lens 20 by the power source of the camera body 10 through the body electric contacts 16 and the lens electric contacts 26 to drive the power zooming motor 31.

As can be seen in Fig. 4, the camera body 10 has a mount switch (switching means) 36 connected to thebody control circuit 35.

Generally speaking, the mount switch is an electric switch similar to the electric contacts 15 or 16, which are widely used in an interchangeable lens camera in which the camera body is provided with electric contacts which come into contact with corresponding electric contacts of the interchangeable lens. The mount switch 36 is turned ON and OFF in accordance with the attachment and detachment of the interchangeable lens to and from the camera body to transmit the necessary signals to the electronic circuits in the camera body 10.

In the illustrated embodiment, the lens attachment and detachment button 13 is associated with the mount switch 36. Namely, when the lens attachment and detachment button 13 is depressed to detach the interchangeable lens 20 from the camera body 10, or when the lock pin 12 is retracted into the body mount 11 by the lens mount 21 while attaching the interchangeable lens 20 to the camera body 10, a projection 13a of the lens attachment and detachment button 13 comes into contact with a contact 36a extending from the mount switch 36. When the projection 13a depresses contact 36a, it becomes disconnected from a contact 36b thus turning the mount switch 36 OFF.

When the mount switch 36 is turned OFF, it is detected in the body control circuit 35 to which the mount switch 36 is connected. As a result, the boay control circuit 35 breaks the power supply line to the electric contacts 16, so that the power supply to the power zooming motor 31 is halted.

Furthermore, the body control circuit 35 is connected to a timer circuit 37 which starts when the mount switch 36 is turned ON (closed). This is the second switching operation.

Namely, upon completion of the attachment of the interchangeable lens to the camera body, the lock pin 12 projects into the lock pin hole 22 to return the lens attachment and detachment button 13 to its original position thereby closing the mount switch 36.

The closure of the mount switch 36 is detected in the body control circuit 35 to which the mount switch 36 is connected. Consequently, the body control circuit 35 activates the timer circuit 37 which then starts counting.

The timer circuit 37 is reset after the lapse of a predetermined time (e. g., a few seconds), and thereafter, the body control circuit 35 establishes a power supply line to the electric contacts 16, so that the motor 31 can be supplied with power.

The timer circuit 37 which is represented by a block in Fig. 4 can be realized by software using an existing microprocessor or the like provided in the camera body 10.

In an interchangeable lens camera as constructed above, to attach the interchangeable lens 20 to the camera body 10, the lock pin 12 and the lens attachment and detachment button 13 are actuated through the lens mount 21 so that the mount switch 36 is turned OFF (opened) in association with the lens attachment and detachment button 13. As a result electrical power supplied to the power zooming motor 31 is halted.

Upon completion of the attachment of the interchangeable lens 20 to the camera body 10, the lens attachment and detachment button 13 is returned to the original position. At that time the mount switch 36 is - is closed in association with the lens attachment and detachment button 13. After the lapse of a predetermined time, the power zooming motor 31 can be supplied with electrical power. When the power supply to the power zooming motor 31 is made possible, the photographer has finished the attachment operation of the interchangeable lens 20 to the camera body 10.

Consequently, even if the photographer unconsciously or accidentally touches the zoom ring 27 upon attachment of the interchangeable lens to the camera body, not only can the power zooming mechanism be effectively prevented from being unexpectedly actuated, but maloperation of the microprocessor which constitutes the body control circuit 35 can also be effectively prevented.

Figure 5 shows another embodiment of the present invention, wherein components common to Fig. 4 bear the same reference numerals. The pair of electric contacts 16 are connected to a power supply circuit 45. The power supply circuit 45 supplies the interchangeable lens 20 with the electric power through the electric contacts 16 and 26, similarly to the body control circuit 35 in Fig. 4. The power supply circuit 45 is connected to the mount switch 36, so that the power supply circuit 45 performs the power supply when the mount switch 36 is turned ON. Conversely, when the mount switch 36 is turned OFF, power supply by the power supply circuit 45 is halted.

The opening of the mount switch 36 is detected in the power supply circuit 45 to which the mount switch 36 is connected. Thereafter, the power supply circuit 45 stops the power supply to the electric contacts 16, thereby halting the supply of electrical power to the power zooming motor 31.

In this illustrated embodiment, upon detaching the interchangeable lens 20 from the camera body 10, the lens attachment and detachment- button 13 is first actuated. Consequently, the mount switch 36 is opened (OFF) in association with the operation of the lens attachment and detachment button 13. After detecting the OFF state of the mount switch 36, the power supply to the power zooming motor 31 is stopped. Consequently, even if the photographer unconsciously or accidentally touches the zoom ring 27 upon detachment of the interchangeable lens 20 from the camera body 10, neither an unexpected operation of the power zooming mechanism nor a maloperation of the electronic circuit employing the microprocessor takes place.

In the illustrated embodiments, the mount switch 36 is used as an electric switch in association with the lens attachment and detachment button (lens detachment operation member) 13, as mentioned above. This contributes to a reduction in the number of components in the camera embodying the present invention in addition to the intended technical advantages mentioned above. Alternatively, it is possible to use a different type of electric switch therefor in addition to the mount switch 36.

Although the zoom operation member is realized by the zoom ring 27 provided in the interchangeable lens 20 in the illustrated embodiments, it is possible to make a zoom operation member with a swingable operation lever similar to a seesaw switch, which rotates or swings in opposite directions in accordance with the zooming directions (wide angle direction or telephoto direction), or two operation buttons corresponding to the zooming directions, etc.

Furthermore, the location of the zoom operation member is not limited to the illustrated embodiments in which the zoom ring 27 is provided on the interchangeable lens 20. It is also possible to provide the zoom ring (zoom operation member) 27 on the camera body 10. In this alternative, the zoom operation switch in association with the zoom operation member and the control circuit 33 for the power zooming motor can be connected to each other by electric contacts similar to the electric contacts 15 in Fig. 1. Alternatively, it is also possible to provide the entirety or part of the control circuit 33 on the camera body 10.

Although the above discussion has been directed to a power zooming interchangeable lens camera, the present - 21 invention can be equally applied to an interchangeable lens camera in which a function other than zooming, such as focusing or exposure, is automated or electronically performed.

As can be understood from the above discussion of the embodiments of the present invention, when the interchangeable lens is attached to the camera body the power supply to the driving mechanisms or the data communication between the interchangeable lens and the camera body is prohibited at the beginning stage of the attachment. When the attachment of the interchangeable lens to the camera body is complete, in one of the embodiments the power supply and the data communication are made possible only after the lapse of a predetermined amount of time. Consequently, even if the photographer unconsciously or accidently touches the operation members upon attachment of the interchangeable lens to the camera body, neither an unexpected operation of the power zooming mechanism nor a maloperation of the electronic circuit employing the microprocessor occur.

Furthermore, with the present invention, upon detachment of the interchangeable lens from the camera body, power supply and data communication are prohibited at the beginning stage of the detachment. Accordingly, even if the photographer unconsciously or accidentally touches the operation members upon detachment of the - 22 interchangeable lens from the camera body, neither an unexpected operation of the power zooming mechanism nor a maloperation of the electronic circuit employing the microprocessor take place.

Claims

CLAIMS:

I. An interchangeable lens camera including a camera body which has electric contacts, and an interchangeable lens which is detachably attached to the camera body and has electric contacts which come into electrical contact with said corresponding electric contacts of the camerq. body when the interchangeable lens is attached to the camera body; wherein said camera body employs a camera system having an outputting means to output electric signals to the interchangeable lens through the electric contacts of the camera body and the interchangeable lens, and wherein said camera body comprises:

a locking means for securing the interchangeable lens to the camera body at a predetermined angular position with respect to the camera body; and, a switching means which permits the outputting means to output electric signals to the interchangeable lens only when the locking means is in an engagement position.
2. An.Lnterchangeable lens camera according to claim 1, wherein said outputting means is a power source means for supplying the interchangeable lens with power through the electrical contacts.
3. An interchangeable lens camera according to claim I or 2, wherein said outputting means comprises a control means which exchanges data, in the form of electric signals, with the interchangeable lens.
4. An interchangeable lens camera according to any one of the preceding claims, wherein said switching means connects or disconnects the outputting means to or f rom the electric contacts of the camera body, respectively.
5. An interchangeable lens camera according to any one of the preceding claims, wherein said camera body has a detachment position on the camera body with which the interchangeable lens must be aligned to as to be detached from the camera body, and a lock position to which the interchangeable lens must be rotated so as to be secured to the camera body and which is provided at a predetermined angular distance from the detachment position with respect to the camera body; and wherein said locking means prohibits the interchangeable lens from rotating on the lens mount when the interchangeable lens is in the lock position.
6. An interchangeable lens camera according to any one of the preceding claims, wherein said locking means is actuated by manipulation of the photographer when the locking means needs to be disengaged to detach the interchangeable lens from the camera body.
7. An interchangeable lens camera according to any one of the preceding claims, wherein said switching means is turned ON and OFF corresponding to engagement and disengagement positions of the locking means, respectively.
8. An interchangeable lens camera according to claim 7, wherein said outputting means is turned ON and OFF to output electric signals to the interchangeable lens through the electric contacts of the camera body and the interchangeable lens, corresponding to the switching means being turned ON and OFF, respectively.
9. An interchangeable lens camera according to any one of the preceding claims, wherein said camera body has a body mount to which the interchangeable lens is detachably attached.
10. An interchangeable lens camera according to claim 9, wherein said electric contacts of the camera body are provided on the body mount.
11. An interchangeable lens camera according to claim 9 or 10, wherein said interchangeable lens has a lens mount which is detachably attached to the body mount.
12. An interchangeable lens camera according to claim 11, wherein said electric contacts of the interchangeable lens are provided on the lens mount.
13. An interchangeable lens camera according to claim 11 or 12, wherein said locking means comprises a pin means which moves into and out f rom the surf ace of the body mount in the optical axis direction with respect to the body mount,, the interchangeable lens being secured to the lens mount when the pin means moves out from the surface of the body mount.
14. An interchangeable lens camera according to claim 13, wherein said switching means is turned ON and OFF corresponding to the pin means moving out from and into the surface of the body mount.
15. An interchangeable lens camera according to any one of the preceding claims, wherein said switching means is turned on immediately after the locking means is disengaged.
16. An interchangeable lens camera according to any one of claims 1 to 14, wherein said switching means further comprises a delay means which turns the switching means ON after a predetermined period of time following the change in position of the locking means from disengagement to engagement.
17. An interchangeable lens camera body comprising:- body electrical contacts for coming into electrical contact in use with corresponding electrical contacts on an interchangeable lens; outputting means for outputting electrical signals in use to the interchangeable lens through said body electrical contacts; locking means for securing the interchangeable lens when attached to the body at a predetermined angular position relative thereto; and switching means for permitting said outputting means to output electrical signals to the interchangeable lens only when said locking means is in an engagement position at said angular position.
18. An interchangeable lens camera substantially as hereinbefore described with reference to the accompanying drawings.
19. An interchangeable lens camera body substantially as hereinbefore described with reference to the accompanying drawings.