JPH0656468B2 - Information transmission method and camera body in camera system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information transmission method in a camera system having a taking lens and a camera body, and a camera body suitable for use in the method.

(Prior Art) A camera in which a taking lens is replaceable usually has an AE (automatic exposure) function, and in order to execute this AE, information about the intrinsic aperture value (open aperture value, minimum aperture value) of the taking lens is provided. ,
And it is necessary to transmit the switching information of the automatic diaphragm control or the manual diaphragm control to the camera body. Therefore, the camera body and the taking lens are respectively provided with electrical contacts for transmitting information in a predetermined relationship.

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

The information transmission electrical contacts described in this publication will be described below with reference to FIGS. 7 (A) to 7 (D). Incidentally, FIG. 7A is a front view of relevant parts of a conventional camera body equipped with an AE function, and FIG. 7B is a perspective view of relevant parts of a conventional taking lens. FIG. 7 (C) is a cross-sectional view schematically showing the peripheral portion of the electric contact shown in FIG. 7 (A) or (B) by cutting along the line I-I in order to explain the function of the contact portion. FIG. 7 (D) is a cross-sectional view schematically showing the peripheral portion of the electrical contact of FIG. 7 (A) or (B) cut along the line II-II.

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

The mount 13 and the mount 17 are made of, for example, a conductive material obtained by plating brass material. These mounts 13 and 15 are used for connecting the camera body 11 and the taking lens 15, and also have a function of electrical grounding.

For example, the mount 13 of the camera body 11 has five electrical contacts.
An electrical contact group 27 having 21a, 22a, 23a, 24a, 25a is provided so as to be electrically insulated from the mount 13 and project from the mount surface (see FIG. 7 (A)).
That is, as shown representatively in FIG. 7 (C),
The electrical contacts 21a to 25a and the mount 13 are electrically insulated by the insulating layer 18. Furthermore, the electrical contacts 21a-25a are
Usually, it projects from the surface of the mount 13 (state shown by a solid line in FIG. 7C). And these contact points 21a-2
5a is provided on the mount 13 via a spring 19 so that it can be pushed into the mount 13 while being pressed when the taking lens 15 is attached to the camera body 11 (state shown by a broken line in FIG. 7C). It is configured.

On the other hand, in the mount 17 of the taking lens 15 corresponding to the electric contact group 27, the electric contact group 29 having five electric contacts 21b, 22b, 23b, 24b, 25b does not protrude from the mount surface. Of course, it is electrically insulated from the mount 17 by the insulating layer 18 and is fixed (see FIG. 7D).

Also, one electrical contact 31 is mounted on the mount 13 of the camera body 11.
a is electrically insulated from the mount 13 and is provided so as not to project from the mount surface (see FIG. 7D). In addition, the shooting lens 1 corresponding to this electrical contact 31a
Mount 17 of 5 has one electrical contact 31b
Are electrically insulated from each other and are provided so as to project from this mount (see FIG. 7 (C)).

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

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

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

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

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

By the way, in recent years, some cameras having an interchangeable photographic lens have an AF (automatic focusing) function (for example, Japanese Patent Laid-Open No. 60-4916). FIG. 8 is a diagram showing a schematic configuration of a camera equipped with such an AF function.

Such a camera has a mechanism for automatically moving the lens in the taking lens to the in-focus position. That is, AF
A shooting lens 41 for a camera that can be used is a plurality of lenses including a lens 43 that is movable to a focus position, a driving force transmission means 45 of the movable lens 43, a unique aperture value of the shooting lens 41, and a combination thereof. A lens ROM (Read Only Memory) 47 that stores information such as shooting conditions according to the lens position moved due to focus (sometimes referred to as unique data of the shooting lens).
It is equipped with

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

The conventional camera body 51 equipped with such an AF function is supposed to be used only with the dedicated taking lens 41. Therefore, various information necessary for realizing AE and AF is also provided through the dedicated information transmission electrical contact 61.

(Problems to be solved by the invention) From the standpoint of the person using the camera, the expensive camera body and shooting lens have compatibility without having to replace each new product released by the manufacturer. It is desirable that it can be used forever.

However, in the conventional camera body equipped with the AF function, there is a problem in that there is no compatible camera lens with both the AE function equipped and the AF function equipped.

Therefore, an object of the first invention of this application is to have a storage means for storing lens-specific information, for example, a lens ROM.
In addition to transmitting information in a camera system that is composed of a photographic lens equipped with an F function and a camera body that can use this photographic lens, the photographic lens for which the photographic lens does not have the above storage means, for example, AE (automatic exposure) An object of the present invention is to provide an information transmission method in a camera system, which enables AE operation even when a conventional photographing lens having only functional equipment is replaced. Another object of the second invention of this application is to provide a camera body suitable for carrying out the information transmitting method of the first invention.

(Means for Solving the Problems) In order to achieve this object, according to the first invention of this application, a photographic lens mounting mount and a photographic lens mounting mount are provided to store lens unique information. An electric contact for supplying power to the camera body for supplying a voltage for driving the storage means to a photographing lens having a storage means for storing the electric power, and the electric contact provided on the mount for mounting the photographing lens separately from the electric contact. And a camera body mounting mount, a storage unit for storing lens-specific information of the first photographing lens, and the camera body mounting mount. An electrical contact connected to a power supply terminal of the storage means, the lens side power supply electrical contact corresponding to the camera body side power supply electrical contact; The first photographing lens, which is provided on the mount for mounting the camera body and has a group of electrical contacts connected to the storage means, the group of electrical contacts on the lens side corresponding to the group of electrical contacts on the camera body side; And a mount for mounting the camera body, and a lens side electrical contact group provided on the camera body mounting mount and corresponding to the camera body side electrical contact group, in which each electrical contact is grounded or ungrounded. Information transmission in a camera system including one photographing lens selected from the second photographing lens, which includes a lens side electric contact group but does not include an electric contact corresponding to the camera body side power supply electric contact In the method, when one of the taking lenses is mounted on the camera body, the one of the taking lenses is connected to an electric contact for supplying power to the camera body. The attached photographing lens is the first photographing lens or the second photographing lens, based on the voltage state of the electric contact for supplying power to the camera body, which changes depending on whether or not there is an electric contact. If it is determined that the attached taking lens is the first taking lens, the camera body side electrical contact group is set to the information between the storage means of the first taking lens and the camera body. Is used as a contact group for serial transmission, and when it is determined that the mounted photographing lens is the second photographing lens, the camera body side electric contact group is changed from the second photographing lens side to the camera. It is characterized in that it is used as a contact group for taking in parallel data to the body side, and information is transmitted between the camera body and one of the taking lenses.

Further, according to the second invention of this application, the mount for mounting the taking lens and the mount for mounting the taking lens are provided,
A camera body side power supply electric contact for supplying a voltage for driving the storage means to a photographing lens having a storage means for storing lens unique information, and the electric contact for the photographing lens mounting mount. And a camera body side electrical contact group provided separately from the camera body side electrical contact group based on a voltage state of the camera body side power supply electrical contact when the taking lens is mounted on the taking lens mounting mount. And a photographic lens determining means for determining whether the attached photographic lens has a storage means for storing the photographic lens specific information, and the photographic lens determining means has a storage means for the photographic lens. If it is determined that the camera body side electrical contacts are serially transmitted between the camera lens storage means and the camera body. When it is determined that the contact point is a contact point and the photographing lens does not have a storage means, a contact function switching circuit is provided that uses the camera body side electric contact group as a contact point for taking in parallel data from the photographing lens side to the camera body side. It is characterized by that.

In implementing the second aspect of the invention, it is preferable that the camera body side power supply electric contact and the electric contact group are provided on the photographic lens mounting mount so as to project from the mount surface.

(Operation) According to the information transmission method of the first invention, the taking lens mounted on the camera body is the first taking lens (hereinafter, referred to as “A
It may also be referred to as "F photographing lens or AF lens". ) Or the second photographing lens (hereinafter, also referred to as "conventional photographing lens or conventional lens") is automatically determined by using the electric contacts for power supply on the camera body side. . Further, based on the above judgment, the electric contact group on the camera body side is used as a contact for serial transmission of information or a contact for reading data in parallel from the photographing lens side, which is suitable for a photographing lens. It is used in the state and information is transmitted.

When a camera system is configured by mounting the first taking lens on the camera body of the second invention, the taking lens storage means (for example, lens ROM) from the camera body side.
On the other hand, the drive voltage of the storage means is supplied via the camera body side power supply electrical contact and the lens side power supply electrical contact.

Further, the photographing lens determining means (CPU in the example of the embodiment) provided in the camera body has a predetermined photographing lens attached to the camera body side power supply electrical contact since the attached photographing lens has a storage means. From the voltage, it is determined that the taking lens mounted on the camera body has the above-mentioned storage means.

Further, the contact function switching circuit provided in the camera body, when the photographing lens judging means judges that the photographing lens has a storage means, the above-mentioned camera body side electrical contact group is used for information between the photographing lens storage means and the camera body. Is a contact for serial transmission.

Therefore, in the camera system configured by mounting the above-mentioned first taking lens on the camera body of the second aspect of the invention, taking a photograph by the AF and AE operations using the lens unique information stored in the storage means of the taking lens. Can be done.

Further, in the camera body of the second invention, the mount structure and the arrangement of the electrical contact groups correspond to those of this camera body, but the storage means (for example, lens ROM) is not provided and the individual electrical contacts are When the second photographing lens in the grounded or non-grounded state, for example, the conventional lens described with reference to FIG. 7 (B) is mounted, the voltage for driving the storage means is normally changed from the camera body side to the photographing lens side. Since it is not supplied, the voltage of the electric contact for body side power supply becomes a value different from a predetermined value, and therefore the photographing lens judgment means of this camera body judges that this photographing lens has no storage means.

Further, the contact function switching circuit provided in the camera body fetches parallel data from the photographing lens side to the camera body side by the above-mentioned electric contact group when the photographing lens judging means judges that the photographing lens does not have a memory means. Contact point.

Therefore, if the photographing lens is, for example, the conventional lens described with reference to FIG. 7 (B), this camera body uses parallel data (for example, open aperture value) via the electrical contacts 21d, 22b, 23b and the camera body side electrical contacts. ) Is taken in, the camera system composed of this camera body and the conventional lens can take a picture by AE operation.

(Embodiment) An embodiment of an information transmission method in a camera system of the first invention and a camera body of the second invention of the present application will be described below with reference to the drawings. It should be noted that these figures schematically show the components necessary for explaining the present invention.
Descriptions of ordinary parts included in the camera body or the taking lens are partially omitted. Further, it is apparent that the size, shape and arrangement relationship of each constituent component are not limited to this illustrated example. Further, in these figures, the same constituents are designated by the same reference numerals.

Description of Camera Body First, an embodiment (which is also an embodiment of the second invention) of a camera body that is one of the components of the camera system that is the subject of the first invention will be described. FIG. 1A is a block diagram schematically showing the internal structure of the camera body.

In FIG. 1 (A), 101 denotes a camera body of the present invention, and 103 denotes a photographic lens mounting mount on which a photographic lens is mounted.

Although details will be described later, the camera body 101 includes a control unit 105, an image pickup unit 106, and a lens driving unit 107.

The photographic lens mounting mount 103 includes a camera body side electrical contact group 175 composed of a plurality of electrical contacts, and a lens ROM (described later) as a storage unit for storing the lens-specific information provided in the photographic lens (described later). ) Is provided with a camera body side power supply electric contact 177 for supplying the lens ROM driving voltage, and electric contacts 179a, 179b and 181.

Further, the control unit 105 of this embodiment includes the microcomputer (CPU) 191, and the camera body side electrical contact group used for exchanging information between the CPU 191 and the photographing lens.
175 function switching circuit 201.

The image pickup unit 106 is connected to the CPU 191 and is used to form an image of a part of the light from the subject that has passed through a photographing lens (not shown) and entered the camera body 101. (C harge C oupled D evise) can be constituted by a circuit including a.

Further, the lens driving means 107 is connected to the CPU 191 and drives a movable lens for automatic focusing provided in a photographing lens (details will be described later).

The main functions of the control unit 105 described above will be described. The CPU 191 of the control unit 105 can perform automatic exposure control (AE). Further, the CPU 191 can perform automatic focusing (AF) control by driving the movable lens in the taking lens to the focusing position by the lens driving means 107 in the camera body 101 according to the information from the imaging unit 106. I can.
Further, the CPU 191 is configured to be able to perform various controls necessary for taking a picture. The contact function switching circuit 201 of the control unit 105 controls each contact of the camera body side electrical contact group 175 when the photographing lens mounted on the camera body 101 has a lens ROM for realizing automatic focusing. When the photographing lens has different focusing points for information transmission and the photographing lens does not have the focusing function (when the lens ROM does not have), the camera body side electrical contact group 175 is one information (parallel data) as a whole. Switch so that it becomes a contact that transmits.

<Description of Each Electrical Contact> Next, the structure and function of each electrical contact will be described with reference to FIGS. 1 (A) and (B) and FIGS. 7 (C) and (D). FIG. 1 (B) is a front view of the essential parts showing the camera body of this embodiment.

The contacts of the camera body side electrical contact group 175 are connected to different ports of the CPU 191 via the contact function switching circuit 201 described above. The camera body side electrical contact group 175 of this embodiment includes, for example, three electrical contacts 175a, 175b and
175c, the contact 175a is the external terminal 201a of the contact function switching circuit 201, the contact 175b is the external terminal 201b of the switching circuit 201, and the contact 175c is the external terminal 201c of the switching circuit 201.
Connect to each.

As described above, each of the electrical contacts 175a, 175b, and 175c functions as a dedicated contact for exchanging different information depending on whether or not the photographing lens mounted on the camera body 101 is equipped with the AF function. Or, each contact functions as a contact for transmitting one information.

The electrical contact 177 for supplying power to the camera body is connected to the external terminal 201d of the switching circuit 201.

The electrical contacts 179a, 179b are for transmitting, for example, minimum aperture value information of the photographing lens to the CPU 191 of the camera body. Further, the electrical contact 181 determines whether to take a photograph by automatic exposure control or manual exposure control.

In this embodiment, the contact points 175a, 175b, 175c, 179a, 179b and 181 are attached to the photographic lens mounting mount 103,
The contacts 21a, 22a, 23a, 24a, 25a, and 31a, which have already been described with reference to FIGS. (A), (C), and (D), are provided with the same arrangement relationship and mechanism. That is, each contact 175a, 175b, 175c, 1
79a and 179b are provided so as to be insulated from the mount 103 and project from the surface of the mount 103. Also, contact 181
Is provided so as to be insulated from the mount 103 and not to project from the mount 103. Further, the electrical contact 177 for supplying power to the camera body is mounted on the mount 103 at a predetermined position.
The mount 103 is provided so as to be projectable from the surface and electrically insulated from the mount 103. The photographic lens mounting mount 103 can be made of a conventionally known material and functions as an electrical ground (ground).

<Description of Contact Switching Circuit> Next, an example of the configuration of the contact function switching circuit 201 will be described with reference to FIG. Figure 2 (A)
FIG. 3 is a block diagram showing a contact function switching circuit.
The contact point function switching circuit is not limited to the example shown in the figure, and can be configured by other hardware or software.

The contact function switching circuit 201 of this embodiment includes 175a, 175b, 1
Four individual switching circuits 21 of the same configuration, each connected to the respective electrical contacts indicated by 75c and 177.
Contains 0.

These individual switching circuits 210 include a first D flip-flop circuit (D-FF) 221, which functions as an input / output switching latch, a second D-FF 223 which functions as an output latch, and a first D-FF 223 which functions as an output buffer. It comprises one three-state buffer 225, a second three-state buffer 227 functioning as an input buffer, and a pull-up resistor 229. The connection relationship between these components and the connection relationship between the individual switching circuit 210 and the electric contact or CPU will be described by taking the electric contact 175a as an example.

The Q output terminal of the first D-FF 221 is connected to the control terminal of the first three-state buffer 225. First DF
The Q output terminal of F221 is connected to the control terminal of the second three-state buffer 227. Also, the Q output terminal of the second D-FF 223 is connected to the input terminal of the first three-state buffer 225. The D of the first and second D-FFs 221, 223
The input terminal is connected to a predetermined port of the CPU 191.

The output terminal of the first three-state buffer 225 is connected to the electrical contact 175 of the body mount 103 via the external terminal 201a of the control unit. The external terminal 201a is also connected to the input terminal of the second three-state buffer 227. The output terminal of the second three-state buffer 227 is the CPU 191.
Connect to the specified port of.

Further, the same voltage (V _DD ) as the power supply voltage of the CPU 191 is supplied to the external terminal 201a via the pull-up resistor 229.

Each individual switching circuit associated with electrical contacts 175b, 175c and 177 is also connected between these electrical contacts and the CPU in the same manner as electrical contact 175 described above.

The switching circuit 201 and the CPU 191 operate as described below in response to an electric signal formed by the voltage state of the camera body side power supply electric contact 177. FIG. 2B is a flow chart showing this operation.

For example, first, "0" is written in the D input of the first D-FF 221 of the individual switching circuit 210 of each of the electrical contacts 175a, 175b, 175c and 177 so that Q = "0" and Q = "1". . At this time, since the output buffer 225 is in the off state and the input buffer 227 is in the on state, the electrical contacts 175a, 175
The voltage states of b, 175c and 177 can be taken into the CPU 191. While the CPU 191 is being activated (step 251), the CPU fetches the signal (voltage state) of the electrical contact 177 into the CPU at a certain fixed cycle (step 252). Then, it is determined whether the signal S ₁ of the electrical contact 177 is "1" or "0" (step 253).

Here, when S ₁ = 0, the CPU 191 determines that the photographing lens mounted on the camera body is a conventional lens.
At this time, since the camera body side electrical contact group 175 is switched so as to function as a contact for capturing the voltage state of each contact, the conventional aperture value information of the photographing lens is captured through the electrical contact group 175 (step 254), the AE operation is controlled as in the conventional case.

On the other hand, when S ₁ = 1, the CPU 191 determines that the taking lens mounted on the camera body is the taking lens equipped with the AF function. Then, "1" is written to the D input of the first D-FF 221 of the individual switching circuit 210 of each of the electrical contacts 175a, 175b and 175c to set Q = "1" and Q = "0". At this time, since the output buffer 225 is in the on state and the input buffer 227 is in the off state, the electric contacts 175a, 175b and 175c of the camera body side electric contact group 175 function as different dedicated contacts for outputting information. Therefore,
Communication with an external circuit becomes possible (step 255).

Description of Photographing Lens Next, referring to FIGS. 3 and 4, as an example of the first photographic lens that can be the other component of the camera system that is the subject of the first invention, a photographic lens equipped with an AF function ( Hereinafter, it may be referred to as an AF lens.).

FIG. 3 is a block diagram schematically showing the internal structure of one embodiment of the AF lens described above.

In FIG. 3, 71 indicates an AF lens. Reference numeral 73 represents a lens ROM provided in the AF lens 71. The lens ROM 73 stores the unique data of the taking lens for realizing the AE and AF operations. Reference numeral 75 denotes a lens side electric contact group which is connected to different information terminals of the lens ROM 73 and corresponds to the camera body side electric contact group 175 (see FIG. 1). This lens side electrical contact group 75 is replaced with three electrical contacts 75
It consists of a, 75b, and 75c.

Reference numeral 77 indicates an electrical contact for controlling the lens ROM. The control electric contact 77 is an electric contact for supplying power to the lens side. The electric contact 77 corresponds to the electric contact 177 for supplying power to the camera body. Through the contacts 177 and 77, a predetermined voltage, for example, the power supply voltage of the CPU 191, is supplied from the control unit 105 of the camera body to the lens ROM 73. Supply. When power is supplied through the lens side power supply electrical contact 77, the lens ROM 73 is in an operating state. Reference numeral 74 indicates a ground terminal. The ground terminal 74 can be connected to, for example, a mount 85 of a taking lens (mount mount 85 for mounting a camera body, see FIG. 4).

Reference numerals 79a and 79b respectively indicate electrical contacts for transmitting the minimum aperture value information to the control unit on the camera body side. Third
In the configuration shown in the figure, a binary digital signal, namely (0
The minimum aperture value information represented by 1) is transmitted. Reference numeral 81 indicates an electrical contact for transmitting switching information for automatic / manual aperture control.

Next, referring to FIG. 4, each of the electric contacts 75a, 75b, 75c,
The mounting state of 79a, 79b and 81 and the lens side power supply electric contact 77 on the AF lens will be described. Incidentally, FIG. 4 is a perspective view schematically showing an example of the configuration of this AF lens.

In this embodiment, the contacts indicated by 75a, 75b, 75c, 79a, 79b and 81 are mounted on the camera body mount 85 of the photographing lens.
In addition, each contact point already described with reference to FIGS. 7 (B) to (D)
21a, 22b, 23b, 24b, 25b and 31b are provided with the same arrangement relationship and mechanism. That is, each contact 75a, 75b, 75c,
79a and 79b are isolated from mount 85 and
It is provided so as not to project from the surface of 85. Also, contact
81 is provided so as to be insulated from the mount 85 and project from the mount 85. Further, the contact 77 is provided at a predetermined position of the mount 85 so as to be capable of protruding from the mount 85 and electrically insulated from the mount 85. The camera body mounting mount 85 can be made of a conventionally known material, and
It functions as an electrical ground.

Further, in FIG. 3, reference numeral 83 denotes a switching means for switching the function of the lens side electrical contact group 73. In the case of this taking lens, the switching means 83 is constructed as described below. That is, one information terminal of the lens ROM73
P as an electronic switch for the electrical contact 75a connected to 73a
The emitter of the NP transistor Tr1 is connected. Similarly, the electric contact 75b connected to the information terminal 73b is connected to the emitter of the PNP transistor Tr2, and the electric contact 75c connected to the information terminal 73c is connected to the emitter of the PNP transistor Tr3. The base of each transistor is connected to a lens ROM control electrical contact 77 connected to the lens ROM 73. Further, whether the collector of each transistor is grounded or opened by an electric circuit is treated in advance according to the type of the photographing lens. For example, in the case of the configuration example shown in FIG. 3, the collector of the transistor is open in Tr1, Tr2 and Tr3.
Then it is grounded. In such a case, when the potential of the control electrical contact 77 becomes substantially equal to the ground, each transistor is turned on, and further, the electrical contacts 75a, 75b, 75
If the voltage is supplied to c through the pull-up resistor as in the conventional case, the voltage state of the contact 75a becomes high level, and the voltage states of the contacts 75b and 75c become low level.

Also, this photographing lens 71 is a lens that can be moved to the in-focus position.
A lens system including 87, and a driving force transmission unit 89 for transmitting the driving force of the lens driving unit 107 of the camera body 101 from the camera body to the lens 87.

Description of Camera System <Usage Example 1> Next, an operation of a camera system in which the above-mentioned AF photographing lens 71 is mounted on the above-mentioned camera body 101 will be described.

FIG. 5 shows the above-mentioned AF lens 7 in the camera body 101.
FIG. 3 is a configuration diagram schematically showing a state in which 1 is attached.

In such a configuration, the control unit 1 of the camera body 101
A predetermined voltage (in this case, the power supply voltage of the CPU 191) is supplied to the lens ROM 73 from 05 via the camera body side power supply electric contact 177 and the lens side power supply electric contact 77. At the same time, this voltage is also supplied to the bases of the PNP transistors Tr1 to Tr3 of the switching means 83. Therefore, the lens ROM 73 operates as specified and the transistors Tr1 to Tr3 are turned off.
Because of this, the circuit between contact 75a and terminal 73a, contact 75b
The circuit between the terminal 73b and the terminal 73b and the circuit between the contact point 75c and the terminal 73c are enabled.

On the other hand, on the camera body 101 side, since the camera body side power supply electric contact 177 contacts the lens side power supply electric contact 77, the voltage state at the electric contact 177 shows a high level. When the electrical contact 177 is in the high-level signal state, the CPU 191 performs the serial transmission operation with the taking lens for the automatic focusing photography and the automatic exposure photography, as already described with reference to FIG. Furthermore, FIG. 2 (A)
As already described using the above, when the voltage state of the electric contact 177 for supplying power to the camera body side is high level, the control unit 1
The switching circuit 210 in 05 includes the electrical contacts 175a, 175b and 17
It operates to make 5c different dedicated contacts for information transmission. Therefore, the control unit 105 of the camera body 101 and the AF
Information can be exchanged by serial transmission with the lens ROM 73 of the lens 71.

This information is passed, for example, as follows. Reset signal (RE) from controller 105 of camera body to contact 175
It is supplied to the lens ROM 73 via a and 75a at a constant cycle. In addition, a clock signal (C
K) is supplied to the lens ROM 73 via the contacts 175b and 75b. On the other hand, in accordance with the reset signal and the clock signal, the control unit 1 from the lens ROM 73 via the contacts 75c and 175c.
Various information including the aperture value information of the photographing lens 71 and the position information of the lens 87 is serially transmitted to 05.

Further, the minimum aperture value information is transmitted via the contacts 179a and 79a and the contacts 179b and 79b.

Further, regarding the switching information of the automatic diaphragm control or the manual diaphragm control, the diaphragm ring (not shown) provided in the AF lens 71 is rotated, and the contact 81 of the camera body contacts the contact 81 of the photographing lens, and the contact 81 does not. It is transmitted by two states.

With such a configuration, it is possible to perform shooting by AF and AE operations.

<Use Example 2> Next, the operation of the camera system configured by mounting the conventional taking lens 15 already described with reference to FIG. 7 (B) on the camera body 101 will be described.

FIG. 6 shows the conventional camera lens 1 in the camera body 101 described above.
FIG. 3 is a configuration diagram schematically showing a state in which 5 is attached.

In such a configuration, since the conventional taking lens 15 does not include an electrical contact corresponding to the camera body side power supply electrical contact 177, the electrical contact 177 directly contacts the mount 17 of the conventional taking lens 15. It will be. Therefore,
This electrical contact 177 is grounded and the voltage state of this electrical contact 177 becomes low level. When the voltage state of the electrical contact 177 is low level, the CPU 191 does not operate under the control of the automatic focusing photography, as already described with reference to FIG.
Further, as already described with reference to FIG. 2A, when the voltage state of the camera body side power supply electric contact 177 is low level, the switching circuit 210 in the control unit 105 and each electric contact 175a, 175b and 175c. It operates so that the voltage state in (3) is always taken into the control unit 105.

By the way, in the conventional photographing lens 15, as described above, for each contact of the electrical contacts 21b, 22b and 23b, one contact is covered with an insulating material and the other contact is connected to the mount. The required treatment is performed in advance for each case.
Therefore, as already described with reference to FIG. 1 (B), the contacts 175a, 175b and 175c on the camera body side are connected to the CPU 1 for example.
When the power supply voltage of 91 is applied, the voltage state of each contact 175a, 175b and 175c on the camera body 101 side corresponding to these contacts is determined depending on whether the contacts 21b, 22b and 23b are insulated or grounded. Therefore, the open aperture value information of the taking lens can be transmitted from the taking lens side to the control unit 105 by the combination of the voltage states.

Also, the minimum aperture value information is the contact points 24b and 179a, and the contact points 25b and 179a.
It is transmitted to the camera body side via 179b.

Further, the switching information of the automatic diaphragm control is transmitted to the camera body side by rotating the diaphragm ring and depending on two states of whether the contact point 181 is in contact with the contact point 181 or not.

These pieces of information are taken into the control unit 105 in the camera body 101.

With such a configuration, the conventional photographic lens can be attached to the camera body of the embodiment having the AF function to perform photographing by the AE operation.

Modifications The present invention is not limited to the above embodiments.

For example, in the above embodiment, the electrical contact group 175 has been described as an example including three electrical contacts. However, the number of electrical contacts that make up this electrical contact group can be changed according to the amount of information to be transmitted and the like.

It is also clear that the number of electrical contacts provided on the camera body and the taking lens can be changed according to the design.

Further, the number of the electric contacts 177 for supplying power to the camera body is not limited to one, and a plurality of such electric contacts 177 may be provided to cause the control unit to perform a more complicated operation by combining the logics of the judgment electric contacts. Is also possible.

Furthermore, the mechanical structures of the mounts of the camera body and the taking lens and the electrical contacts described in the above embodiments are merely examples, and these structures may be variously modified within the scope of the object of the present invention. I can. For example, the concavo-convex state with respect to the mount of the electrical contacts provided on the mount of the camera body and the mount of the taking lens may be changed to the concavo-convex state opposite to the configuration of the embodiment.

(Effects of the Invention) As is apparent from the above description, according to the information transmission method in the camera system of the first invention of the present application and the camera body of the second invention, the taking lens mounted on the camera body is the first. Whether the lens is the second lens or the second lens is automatically determined by using the electrical contacts for power supply on the camera body side, and the group of electrical contacts on the camera body side is photographed based on the above determination. It can be used in a state suitable for a lens to transmit information. For this reason,
When the first taking lens having a storage means for storing the lens specific information is used as the taking lens, AE is used.
Also, it enables photography by AF operation. Further, even when the taking lens mounted on the camera body does not have a storage unit for storing lens-specific information, for example, a lens ROM, and the taking lens is incapable of performing an AF operation, the taking lens does not perform such photographing. It is possible to automatically determine that the lens is a lens, and the parallel information is taken into the camera body side from this taking lens to enable photography by AE operation.

Therefore, in a camera system including a photographing lens having a storage unit, for example, a lens ROM that stores lens-specific information for realizing the AF function, and a camera body that can use this photographing lens, the photographing lens is A photographic lens having no storage means, for example, a camera system excellent in compatibility that enables AE (automatic exposure) operation even when the photographic lens is replaced with a conventional photographic function-equipped camera system. It is possible to provide a suitable camera body with excellent compatibility.

[Brief description of drawings]

FIG. 1 (A) is a block diagram showing an embodiment of a camera body, FIG. 1 (B) is a front view of an essential part showing an embodiment of the camera body, and FIG. 2 (A) is provided in the camera body. FIG. 2 (B) is a block diagram showing a contact function switching circuit, FIG. 2 (B) is an operation flow chart showing an example of the function of the control unit provided in the camera body, and FIG. 3 is a block diagram showing an embodiment of a photographing lens equipped with an AF function. 4, FIG. 4 is a perspective view showing a taking lens equipped with an AF function, FIG. 5 is a configuration diagram showing a usage example 1 of a camera system, and FIG. 6 is a configuration diagram showing a usage example 2 of the camera system. 7 (A) and 7 (B) are explanatory views of a conventional camera equipped with an AE function, and FIGS. 7 (C) and 7 (D) are sectional views showing conventional and information transmission electrical contacts according to the present invention. FIG. 1 is a block diagram showing a conventional camera equipped with an AF function. 71 …… Shooting lens, 73 …… Lens ROM 74 …… Ground terminal, 75 …… Lens side electrical contact group 77 …… Lens side power supply electrical contact 79a, 79b, 81 …… Electric contact, 83 …… Switching means 85 …… Camera body mounting mount 87 …… AF movable lens 89 …… Driving force transmission means Tr1 to Tr3 …… PNP transistor 101 …… Camera body 103 …… Shooting lens mounting mount 105 …… Control section, 106 ...... Imaging unit 107 …… Lens driving means 175 …… Camera body side electrical contacts 177 …… Camera body side power supply electrical contacts 179a, 179b, 181 …… Electrical contacts 201 …… Contact function switching circuit 210 …… Each Individual switching circuit for each electrical contact 221,223 D flip-flop circuit 225,227 Three-state buffer 229 Pull-up resistor.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location // G02B 7/20 6920-2K (56) References JP-A-61-103375 (JP, A) JP-A-54-108628 (JP, A) JP-A-58-95721 (JP, A) JP-A-59-188609 (JP, A)

Claims (3)

[Claims] 1. A photographic lens mounting mount and a photographic lens provided on the photographic lens mounting mount and having storage means for storing lens-specific information, are supplied with a voltage for driving the storage means. A camera body side power supply electric contact for, and a camera body side electric contact group provided separately from the electric contact in the photographic lens mounting mount, and a camera body mounting mount, Storage means for storing the lens-specific information of the first photographing lens, and electrical contacts provided on the camera body mounting mount and connected to a power supply terminal of the storage means, the camera body side power supply Lens-side power supply electric contacts corresponding to the electric contacts for electric power, and electric contacts provided on the camera body mounting mount and connected to the storage means. The first photographing lens having an air contact group and a lens side electric contact group corresponding to the camera body side electric contact group, and a camera body mounting mount, and the camera body mounting mount. A lens-side electric contact group corresponding to the camera-body-side electric contact group, each electric contact including a lens-side electric contact group in a grounded or non-grounded state. A method for transmitting information in a camera system comprising one taking lens selected from a second taking lens having no electrical contact corresponding to the contact, wherein the one taking lens is attached to a camera body when the one taking lens is attached to the camera body. Electricity for supplying power to the camera body, which changes depending on whether one of the photographing lenses has an electric contact corresponding to the electric contact for supplying power to the camera body It is determined whether the attached taking lens is the first taking lens or the second taking lens based on the voltage state of the point, and the attached taking lens is the first taking lens. If it is determined that there is, the camera body side electrical contact group is used as a contact group for serially transmitting information between the storage unit of the first photographing lens and the camera body, and the mounted photographing lens is When it is determined to be the second photographing lens, the camera body side electric contact group is used as a contact group for taking in parallel data from the second photographing lens side to the camera body side. An information transmission method in a camera system, which is characterized in that information is transmitted between photographing lenses. 2. A photographic lens mounting mount, and a photographic lens provided on the photographic lens mounting mount and having storage means for storing lens-specific information, a voltage for driving the storage means is supplied. In the camera body, the camera body side power supply electric contact for supplying power and a camera body side electric contact group provided separately from the electric contact on the photographing lens mounting mount, Based on the voltage state of the electric contacts for supplying power to the camera body when the lens is attached, it is determined whether or not the attached photographic lens has a storage unit for storing photographic lens specific information. The photographing lens determining means that determines whether the photographing lens has the storage means, and the photographing lens determining means determines that the photographing lens has the storage means. If it is determined that the air contact group is a contact for serially transmitting information between the photographing lens storage means and the camera body, and the photographing lens does not have a storage means, the camera body side electrical contact group is set to the photographing lens side. The camera body is provided with a contact function switching circuit that serves as a contact for taking in parallel data from the camera body to the camera body side. 3. The camera body according to claim 2, wherein the camera body side power supply electric contact and the electric contact group are provided on the photographing lens mounting mount so as to project from the mounting surface. A camera body featuring.