JP2000180699A - Zoom lens and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a camera angle from largely changing even when a zoom lens is loaded on a camera body comprising an image pick-up element of small image size for cost reduction, by communicating with a camera and determining a zoom range on the basis of the data intrinsic to the obtained camera. SOLUTION: This camera system comprises a camera body 1 using IX240 cartridge film or a digital camera body 50 applying an image pick-up element such as CCD and the like, and a zoom lens 100. LCPU 101 in the zoom lens 100 transmits and receives the command and the data on the basis of the demand of communication from FCPU 2 or DCPU 51 in the body, and executes the predetermined operation on the basis of the received command data and the control data. That is, the zoom lens 100 which can be used in common, communicates with the camera body, and receives the data intrinsic to the camera body. The zoom range is determined on the basis of the obtained data corresponding to the camera body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera body having at least two types of different image sizes, and a zoom lens that can be shared by the camera bodies.

[0002]

2. Description of the Related Art Two types of camera bodies using different recording media, such as a camera body using a silver halide film, a camera body using an image pickup device such as a CCD (Charge Coupled Device), and both camera bodies. Various technologies have been developed for camera systems having an interchangeable lens that can be used in common. For such a camera system, for example, the related art is described in "Photographic Industry (April 1998, P97 to P100)".

Here, when a common interchangeable lens is used for both camera bodies, the two camera bodies have no significant difference in the angle of view, so that they can be used without discomfort. It is considered desirable that the sizes, that is, the sizes of the photographing screens, be uniform. Generally, the image size of a silver halide film is 36 mm × 24 mm when a 135 format roll film is used.
mm, and even when an IX240 cartridge film is used, it is 27.4 mm in the case of the H type.
× 15.6 mm.

Therefore, in order to obtain the same angle of view in the digital camera body, the first method using an image sensor having the same image size or the use of a reduction optical system behind the image forming plane is used to reduce the image size. It is necessary to reduce the size and adopt the second method using a small image sensor.

The second method has an advantage that a small CCD can be used, but has a drawback that a camera is large and heavy because a space is required for a reduction optical system. On the other hand, the first method is advantageous in terms of the size and weight of the camera, but has the disadvantage of requiring a large-sized image pickup device and increasing the cost.

By the way, in an image pickup device such as a CCD, firstly, as the chip size becomes larger, the number of chips taken from a semiconductor wafer becomes smaller as the chip size becomes larger by simply considering the area ratio due to the semiconductor manufacturing process, resulting in an increase in cost. . Second, the larger the chip size, the lower the chip yield, which leads to an increase in cost. This is the acceleration condition for the first problem. Third, since the semiconductor wafer is usually circular and the imaging device is usually rectangular, the larger the chip size, the greater the waste in the peripheral area and the higher the cost. This is also the acceleration condition for the first problem.

[0007] As described above, when the current semiconductor manufacturing technology is assumed, it is not necessary to stick to making the sizes of the two images, that is, the sizes of the photographing screens, rather, it is necessary to balance the cost with the size of the imaging device. It is considered necessary to make the height slightly smaller than that of the silver halide film to allow for a change in the angle of view.

[0008]

However, in the case of adopting a method of balancing the cost and making the size of the image pickup device slightly smaller than that of the silver halide film and allowing a change in the angle of view, as described above, Since the image size of the image sensor is small, the angle of view of the image is reduced. That is, when a wide-angle lens is mounted, the usability is close to that of a standard lens, and there is a problem that it becomes difficult to take advantage of the characteristics of the wide-angle lens.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce cost even if the camera body is mounted on a camera body using an image sensor having a small image size with priority given to cost. Compared to when mounted on a camera body using film that is the image size,
An object of the present invention is to prevent a photographing angle of view from largely changing by widening a variable range of a focal length of a zoom lens.

[0010]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a zoom lens attachable to a camera, which communicates with the camera and transmits data unique to the camera. Communication means for receiving, zoom range determining means for determining a zoom range based on data unique to the camera obtained by the communication means, and zooming within the zoom range determined by the zoom range determining means. There is provided a zoom lens comprising: a zoom driving unit for driving.

According to a second aspect, the present invention provides a zoom lens freely attachable to a camera, a communication means for communicating with the camera and receiving data unique to the camera, and a focal length detecting means for detecting a set focal length. Means, based on the data corresponding to the type of camera obtained by the communication means and the focal length obtained by the focal length detection means, a shooting possibility determination means for determining whether shooting is possible, and communicates with the camera. And a transmitting means for outputting to the camera determination data indicating whether or not shooting is possible.

According to a third aspect, a camera is provided with a zoom lens, which communicates with the zoom lens and receives data specific to the zoom lens and data corresponding to a set focal length of the zoom lens. Communication means;
There is provided a camera comprising: a photographing possibility determination unit that determines photographing possibility according to data unique to the zoom lens and data corresponding to a focal length.

According to the above-described first to third aspects, the following operations are provided.

That is, in the first aspect of the present invention, communication with the camera is performed by the communication means, data unique to the camera is received, and data unique to the camera obtained by the communication means by the zoom range determination means. Is determined on the basis of the zoom range, and zoom driving is performed by the zoom driving unit within the range of the zoom range determined by the zoom range determining unit.

In the second aspect, the communication means communicates with the camera, data unique to the camera is received, the focal length set by the focal length detecting means is detected, and the photographing availability determining means detects the focal length. Based on the data corresponding to the type of camera obtained by the communication unit and the focal length obtained by the focal length detection unit, determination of whether or not shooting is possible is performed, and the transmission unit communicates with the camera and communicates with the camera. In response to this, the determination data indicating whether or not shooting is possible is transmitted.

In the third mode, the communication means communicates with the zoom lens, and data unique to the zoom lens and data corresponding to the set focal length of the zoom lens are received. The determination as to whether or not shooting is possible is made according to the data unique to the zoom lens and the data corresponding to the focal length.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external structural view of a camera according to a first embodiment of the present invention.

FIG. 1 shows a state in which a zoom lens 100 is mounted on a camera body (hereinafter, referred to as an IX240 body) using an IX240 cartridge film. Such a zoom lens 100 is a CCD
Digital camera body using an image sensor such as
Digital body). The zoom lens 100 has a TELE S for zoom operation.
W103 and WIDESW104 are provided at predetermined positions on the side surface as shown.

FIG. 2 is a block diagram of a camera system employing a zoom lens and a camera according to the first embodiment of the present invention.

As shown in FIG. 1, the camera system includes an IX240 body 1 or a digital body 50 and a zoom lens 100.

First, the internal configuration of the IX240 body 1 will be described.

In FIG. 2, an FCPU 2 such as a microcomputer is provided inside the IX240 body 1 and is communicably connected to the exposure control unit 6.
The exposure control section 6 controls exposure of a body such as a shutter. Further, the FCPU 2 is electrically connected to a 1RSW that turns on in a first stroke of the release operation and a 2RSW 5 that turns on in a second stroke. Further, the IX 240 body 1 is provided with a mount contact 3, and the connection with the mount contact of the zoom lens 100 enables communication between the FCPU 2 and the zoom lens.

The IX240 body 1 uses the IX240 cartridge film 7 as a recording medium. The image size of the IX240 cartridge film 7 is 27.4 mm for the H type as shown in the figure.
× 15.6 mm, and the diagonal length is 31.5 mm
It is.

Next, the internal configuration of the digital body 50 will be described.

Referring to FIG. 2, a digital body 50 has a D
A CPU 51 is provided. The DCPU 51 includes an exposure control unit 60, a CCD driver 55, an image processing circuit 57,
It is communicably connected to the image recording circuit 58. The exposure control section 60 is for performing exposure control on the digital body 50 side such as a shutter. The CCD driver 55 is connected to the CCD 56 and controls the driving of the CCD 56. The output of the CCD 56 is connected to an image processing circuit 57.
A / D conversion, color conversion,
Processing such as data compression is performed.

The output of the image processing circuit 57 is connected to the input of an image recording circuit 58,
Then, the image data subjected to the various processes described above is stored in the recording medium 5.
Write 9 In addition, the DCPU 51 includes a 1RSW 53 that is turned on in the first stroke of the release operation,
The 2RSW 54 that is turned on in the second stroke is electrically connected. The image size of the CCD 56 is 17 mm × 12 mm as shown, and the length of the diagonal line is 20.8 mm. The diagonal length of the image size in the case of the IX240 body 1 is 31.
Since it is 5 mm, in the case of the digital body 50, the shooting angle of view is narrowed to about 66%.

Next, the internal structure of the zoom lens 100 will be described.

Referring to FIG. 2, an LCPU 101 is provided inside the zoom lens 100 by a microcomputer or the like for controlling the entire system. This LCPU 101
Is output from the zoom motor 1 via the zoom drive circuit 106.
05 is connected to the input. This zoom motor 105
Is for driving a zooming mechanism, and is driven and controlled by the zoom drive circuit 106. The zoom state (corresponding to the focal length) of the zooming mechanism is detected by the zoom encoder 107, and the detection result is obtained by the LCPU 1
01 is fed back.

The output of the LCPU 101 is supplied to the stepping motor 1 via a stepping motor driving circuit 113.
12 is connected. This stepping motor 112
Is for driving the aperture mechanism 111, and is driven and controlled by the stepping motor drive circuit 113.
Further, the output of the LCPU 101 is connected to the input of the LD motor 108 via the LD motor drive circuit 109. The LD motor 108 drives a lens focusing mechanism, and is driven and controlled by an LD motor drive circuit 109. The driving amount of the LD motor 108 is detected by the LD encoder 110 and the LCPU 101
Will be fed back.

In addition, the LCPU 101 can communicate with the IX 240 body 1 or the digital body 50 via the mount contact 102. Also, the LCPU 10
1 is TELE S for zooming to the TELE side.
W103, WIDE for zooming to WIDE side
It is electrically connected to the SW 104.

Referring now to FIG. 3, the difference in the zoom range of the zoom lens 100 when the IX240 body 1 and the digital body 50 are mounted will be described.

The zoom lens of the present invention has a different focal length variable range (hereinafter referred to as a zoom range) depending on whether the zoom lens is mounted on the IX240 body 1 or mounted on the digital body 50. In FIG. 3, the horizontal axis represents the focal length of the zoom lens, and the vertical axis represents the number of resolutions at the periphery of the screen. The number of resolutions indicates how many lines can be resolved on the imaging plane when the specified test chart is photographed at the specified magnification. Usually, it is indicated by the number / mm. The RPTH on the vertical axis indicates the allowable number of resolution lines in the peripheral portion of the screen.

The vertical axis in FIG. 3 represents the number of resolutions at the periphery of the screen, but does not represent the absolute value of (number / mm).
It is expressed as a relative value to TH.

Here, in the case of the IX240 body 1, the diagonal length of the image size (hereinafter referred to as IS) is IS
= 31.5 mm, and the number of resolutions at the periphery of the screen is R when the focal length of the lens is between 35 mm and 105 mm.
Exceeds PTH. Therefore, a zoom range of 35 mm to 105 mm is a usable range.

In the case of the digital body 50, IS =
Since it is as small as 20.8 mm, the deterioration of the resolution at the peripheral portion of the screen is smaller than that of the IX240 body 1. At the periphery of the screen, the aberration increases and the image quality (the number of resolutions) deteriorates.
The degree increases according to the distance from the center of the screen.
Therefore, in the case of the digital body 50, the zoom range is 28
The range of mm to 120 mm is a usable range.

Hereinafter, referring to the flowchart of FIG.
An operation sequence of the LCPU 101 of the zoom lens 100 will be described.

LCPU 101 in zoom lens 100
Is transmitted from the FCPU 2 or the DCPU 51 in the body in response to a communication request from the FCPU 2 or the DCPU 51 in the body.
Then, commands and data are transmitted and received, and a predetermined operation described in detail below is executed according to the received command data and control data.

That is, when a communication request is received from a body (step S1), communication with the body (body communication) is performed.
Is executed (step S2). The type of command data obtained by the body communication is determined, and if the command data is “image size / data write”, the process proceeds to step S4 (step S3).

Then, in step S2, the image size data (IS) of the body is sent as control data along with the command data. If the image size data is IS ≧ 23 mm, the zoom range is set to 35 mm.
１０５105 mm (steps S4 and S5), and IS <
In the case of 23 mm, the zoom range is 28 mm to 120 m
m (steps S4 and S6).

If the command data obtained by the body communication in step S2 is "zoom enable", a subroutine "zoom enable" is executed (steps S7 and S8). The sequence of this subroutine "zoom enable" will be described later in detail with reference to FIG.

If the command data obtained by the body communication in step S2 is "AV narrowing down", "AV narrowing down" is performed (steps S9 and S1).
0). In this “AV focusing”, the stepping motor 112 is controlled under the control of the stepping motor driving circuit 113.
Is driven to narrow down the aperture mechanism 111. In the body communication in step S2, since data corresponding to the number of steps to be narrowed down from the open state is received as control data following the command data, narrowing down is performed according to the data. After the end of the above operation, communication is performed with the body, and command data indicating the end of the narrowing down of the AV is transmitted to the body (step S11).

If the command data obtained by the body communication in step S2 is "AV release",
"AV release" is performed (steps S12 and S13). This “AV release” is an operation of opening the aperture to a fully open state regardless of the current aperture stop state. Under the control of the stepping motor driving circuit 113, the stepping motor 112 is operated to open the aperture mechanism 111. It will open to the fully open state. After the "AV release" is completed, communication with the body is performed, and command data indicating the end of the AV release is transmitted to the body (step S14).

If the command data obtained by the body communication in step S2 is "LD drive", "LD drive" is performed (steps S15 and S16).
In this “LD drive”, the LD motor 108 is driven under the control of the LD motor drive circuit 109. At this time, the 2-byte data including the control data 1 and 2 communicated together with the command data, the driving direction of the LD drive and L
The D drive amount is specified. After the "LD drive" is completed,
The body communication is performed, and command data indicating the end of LD driving is transmitted to the body (step S17).

If the command data obtained by the body communication in step S 2 is “read focal length”, the output signal from the zoom encoder 107
The zoom encoder value is read (step S18,
S19). Then, the focal length of the lens is calculated from the read zoom encoder value (step S2).
0), communicate with the body, and transmit focal length data (step S21).

If the command data obtained by the body communication in step S2 is "lens attachment detection", communication with the body is performed and the lens ID number (type identification number) is transmitted to the body (step S2). Step S22, S
23). Then, communication with the body is performed, and the parameters of the lens are communicated to the body. The parameters of the lens are parameters such as the open aperture value and the number of stops (step s24).

Steps S5, S6, S11, S1
After completion of steps 4, S17, S21, S24 and step S2
If the determination of No. 2 is No, the process returns to step S1.

Next, a detailed sequence of the subroutine "zoom enable" executed in step S8 of FIG. 4 will be described with reference to the flowchart of FIG.

When the subroutine "zoom enable" is entered, first, the state of the TELE SW 103 is monitored (step S50). (Zooming to the side) is started (step S51).

Subsequently, according to the output signal from the zoom encoder 107, the zooming mechanism sets the TEL within the zoom range.
It is determined whether or not the E limit value has been reached (step S5)
2). Here, when the TELE limit value is reached, a short brake (zoom motor short circuit) is applied to the zoom motor 105 (step S53), and the zoom motor 105 is turned off (non-operating) (step S5).
4), monitor the state of the TELE SW103 and
It waits until the E SW is turned off, and if it is turned off, the process proceeds to step S68 (step S5).
5).

On the other hand, in step S52,
When the zooming mechanism has not reached the TELE limit value of the zoom range, the LCPU 101 sets the TELE SW 103
Is confirmed (step S56), and the TELE S
If W103 is ON, the process returns to step S52, and TE
If the LE SW 103 is OFF, the zoom motor 105
Is short-circuited (zoom motor short-circuit) (step S57), and the zoom motor 105 is turned off.
After entering the (non-operation) state (step S58), the process proceeds to step S68.

On the other hand, in step S50, TE
When the LE SW 103 is OFF, the WIDE SW
104 is monitored (step S59), and the corresponding WID
If the ESW 104 is ON, the zoom motor 105 and the zoom drive circuit 106 are operated to perform WIDE drive (WIDE drive).
(Zooming to the side) is started (step S60). Subsequently, when the zooming mechanism has reached the wide limit value of the zoom range (step S61), a short brake (zoom motor short circuit) is applied to the zoom motor 105 (step S62), and the zoom motor 105 is turned off (step S62). (Non-operation) state (step S63), and the WIDE SW1
04, and waits until the WIDE SW 104 is turned off.
When the state becomes the F state, the process proceeds to step S68 (step S64).

On the other hand, in step S61, when the zooming mechanism has not reached the wide limit value of the zoom range, if the WIDE SW 104 is ON, the process returns to step S61, and the WIDE SW 104 is turned OFF.
If so, a short brake (zoom motor short circuit) is applied to the zoom motor 105 (step S66), the zoom motor 105 is turned off (non-operating), and the process proceeds to step S68 (step S67). Step S68
In, if there is a communication request from the CPU in the body, the process returns to step S2 in FIG. 4 described above, and if there is no communication request, the process returns to step S50 in FIG.

Next, referring to the flowchart of FIG.
The sequence on the camera body side will be described in detail.

When the power switch (not shown) is turned on, communication with the zoom lens 100 is performed, and the mounting of the zoom lens 100 is detected (step S100). At this time, an ID number and lens parameters of the zoom lens 100 are received from the zoom lens 100. If the communication is successful, it is determined that the zoom lens 100 is mounted, and the process proceeds to step S102. If the communication is not successful, it is determined that the zoom lens 100 is not mounted, and the process proceeds to step S100. Return to

Next, in step S102, communication with the zoom lens 100 is performed, and image size data (IS) corresponding to the body is transmitted from the body. That is, if the body is IX240 body 1, IS = 31.
5mm, IS = 20.8m for digital body 50
Send m.

Subsequently, the state of the 1RSW 4 or 53 is detected, and if the 1RSW 4 or 53 is ON, the process proceeds to step S
The process proceeds to step S106, and if the 1RSW 4 or 53 is not ON, the process proceeds to step S104 to perform lens communication and detect lens attachment (step S105). In this step S105, the process returns to the step S103 when the lens is mounted, and returns to the step S100 when the lens is not mounted.

Next, communication with the zoom lens 100 is performed, and the focal length is read from the zoom lens 100 (step S106). Then, photometry is performed using a photometric element (not shown), and exposure calculation is performed based on the photometric result (step S107). Further, the distance is measured using a distance measuring element (not shown), and the amount of driving of the lens is calculated from the result of the distance measurement (step S108).

Subsequently, communication with the zoom lens 100 is performed, and LD driving is performed in accordance with the lens driving amount obtained above (step S109). And 2RSW5 or 5
4 is monitored, and if 2RSW5 or 54 is ON, the process proceeds to step S112. If 2RSW5 or 54 is not ON, at step S111, 1RSW4 or 5
3 is monitored, and if the 1RSW 4 or 53 is ON, the process returns to step S110;
Return to

Subsequently, in step S112, lens communication is performed and "AV narrowing down" is performed. Then, exposure is performed (step S113). In the case of the IX240 body 1, the exposure is performed on the film using the exposure control unit 6, and in the case of the digital body 50, the exposure control unit 60 is used to perform the exposure from the CCD image pickup device. Get the data.

Next, lens communication is performed and "AV release" is performed.
Is performed (step S114). Then, after the operation, charging is performed in the shutter in the exposure control unit 6 or 60 (step S115). The shutter is a focal plane shutter operated by a spring force, and it is necessary to charge the spring after the operation.

Subsequently, when the image pickup medium is a film, that is, when the IX240 body 1 is used, the film is wound up and the process returns to the step S103 (step S103).
116, S117). On the other hand, when the image pickup medium is an image pickup element, that is, when the digital body 50 is used, image data processing is performed using the image processing circuit 57, and the image recording circuit 58 is used to perform image data processing. And the process returns to step S103 (step S11).
6, S118, S119).

Next, a second embodiment of the present invention will be described.

FIG. 8 is a block diagram of a camera system employing a zoom lens and a camera according to a second embodiment of the present invention. Here, the same components as those in FIG. 2 described above are denoted by the same reference numerals, and description thereof is omitted.

This camera system comprises an IX240 body 1, a digital body 50, and a zoom lens 100. Explaining only the differences from the configuration of FIG.
The display unit 9 and the display driver 8 are provided in the IX240 body 1. The display unit 9 performs a display such as a warning display, and is driven and controlled by the display driver 8. Similarly, a display driver 61 and a display unit 62 are provided in the digital body 50. On the other hand, the zoom lens 100 is provided with a zoom tube 14 for performing a zoom operation. The form of the zoom ring 114 is as follows.
This is as shown in FIG. This is an operation member for the photographer to perform zooming by manual operation. The zoom mechanism 115 is driven in conjunction with the driving of the zoom ring 114.

Hereinafter, referring to the flowchart of FIG.
LCPU1 in the zoom lens 100 according to the second embodiment
The lens sequence of No. 01 will be described.

Incidentally, those having the same step numbers as those shown in FIG. 4 perform the same operations.

When a communication request is received from the body (step S1), communication with the body (body communication) is executed (step S2). The type of the command data obtained by the body communication is determined, and if the command data is “image size / data write”, the process proceeds to step S151 (step S150). In step S151, since the body image size data (IS) is transmitted as control data following the command data in the body communication, the IS data is
It is stored in the memory inside the LCPU 101.

If the command data obtained by the body communication in step S2 is "focal length reading" (step S152), the zoom encoder value is read from the output signal from the zoom encoder 107 (step S153). Then, the focal length of the lens is calculated from the zoom encoder value read as described above (step S154). If the image size data stored in the memory inside the LCPU 101 is IS <23 mm, the process proceeds to step S157, and if IS ≧ 23 mm, the process proceeds to step S156 (step S155).

The process proceeds to step S156 when the IS is larger than 23 mm. However, since the zoom range in which the resolution characteristics of the peripheral portion of the screen is guaranteed is 35 mm to 105 mm, when 35 mm ≦ focal length ≦ 105 mm Indicates that shooting (release) is possible, and proceeds to step S157. On the other hand, focal length <35 mm or focal length> 105 m
In the case of m, the resolution characteristics around the screen are not guaranteed.
In step S158, body communication is performed, and command data of "release not possible" is transmitted to the body. If the zoom range is within the zoom range, the focal length data is transmitted to the body (step S157). Other processes (steps S9 to S24) are the same as those in FIG.

Next, the sequence on the body side in the second embodiment will be described in detail with reference to the flowchart in FIG.

Steps for performing the same processing as in FIG. 6 according to the first embodiment described above are given the same step numbers, and descriptions thereof are omitted.

In steps S200 and S201, communication with the zoom lens 100 is executed, and the mounting of the zoom lens 100 is detected. At this time, an ID number and lens parameters of the zoom lens 100 are received from the zoom lens 100. If this communication is successful, it is determined that the zoom lens 100 is attached, and step S10 is performed.
3 and if the communication fails, it is determined that the zoom lens 100 is not mounted, and step S1 is performed.
Return to 00.

In step S106, when the focal length data is received from the lens, the process proceeds to step S201 assuming that the release is possible, and when the command data of "release not possible" is received from the lens, the release is performed. Since it is impossible, the process proceeds to step S202, a warning is displayed on the display unit 9 or 62 indicating that the release is impossible, and the process returns to step S103. As described above, when the release is impossible, the predetermined warning display is performed, so that a malfunction can be prevented.

Next, a third embodiment of the present invention will be described.

Note that the IX24 constituting the third embodiment is
0 body 1, digital body 50, zoom lens 100
Is the same as that of the above-described second embodiment (FIG. 8), and therefore, in the following description, the same components will be denoted by the same reference characters, and will not be described in detail below. Is omitted.

Hereinafter, referring to the flowchart of FIG. 11, the LCP in the zoom lens 100 of the third embodiment will be described.
The lens sequence executed by U101 will be described.

In FIG. 11, steps that perform the same processing as in FIG. 4 described above are given the same step numbers, and detailed descriptions thereof are omitted.

In FIG. 11, after performing the same processing as in FIG. 4 in steps S1 and S2, if the command data obtained by the body communication is “lens attachment detection”, the flow proceeds to step S251 (step S250). The subsequent processing is characteristic.

That is, in this embodiment, when the lens attachment is detected, communication with the body is performed first, the lens ID number is transmitted to the body (step S251), communication with the body is performed, and zooming is performed on the body. Range 1 (IS <2
A zoom range at 3 mm is transmitted (step S252), communication is performed with the body, and a zoom range 2 (zoomable range at IS = 23 mm) is transmitted to the body (step S253). ), Communicate with the body, and communicate lens parameters to the body. The parameters of the lens are parameters such as the open aperture value and the number of steps of stopping down (step S254).

Next, a sequence on the camera body side will be described with reference to FIG.

In FIG. 12, steps for performing the same processing as in FIG. 6 described above are denoted by the same step numbers, and detailed description is omitted.

When a power switch (not shown) is turned on, first, lens communication is performed, and attachment of the zoom lens 100 is detected. Here, the ID number of the zoom lens 100, the zoom range 1, the zoom range 2,
And lens parameter information (step S30)
0). In step S301 in the figure, the same processing as in step S301 is performed.

In step S302, if IS <23 mm, step S10 is executed according to the image size of the body.
7 and if IS ≧ 23 mm, the process proceeds to step S303. In step S303, when the focal length of the zoom lens 100 received from the zoom lens 100 in step S106 is within the zoom range 2, the resolution characteristic of the peripheral portion of the screen is guaranteed. And proceeds to step S107. If the focal length is not within the range of the zoom range 2, since the resolution characteristic of the peripheral portion of the screen is not guaranteed, it is determined that the release is impossible, and the process proceeds to step S304. In step S304, a warning is displayed on the display unit 9 or 62 indicating that release is not possible, and the process returns to step S103.

The above embodiments of the present invention include the following inventions.

That is, there are at least two or more types of camera bodies having different image sizes, and a zoom lens that can be mounted on the camera bodies having different image sizes and can be used in common. Communication means for communicating with the camera body and receiving data unique to the camera body; and zoom range determination means for determining a zoom range according to the data corresponding to the camera body obtained by the communication means. And a zoom drive unit for performing a zoom drive within a range of the zoom range determined by the zoom range determination unit.

[0087]

As described in detail above, according to the present invention,
Even when mounted on a camera body that uses an image sensor with a small image size to prioritize cost, the focal length of the zoom lens can be changed more than when mounted on a camera body that uses film with a large image size. It is possible to provide a zoom lens and a camera that prevent a photographing angle of view from being largely changed by increasing.

[Brief description of the drawings]

FIG. 1 is an external configuration diagram of a camera according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a camera system employing a zoom lens and a camera according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a difference in a zoom area of the zoom lens 100 when the IX240 body 1 and the digital body 50 are mounted.

FIG. 4 is an LC of the zoom lens 100 according to the first embodiment;
4 is a flowchart illustrating an operation sequence of the PU 101.

FIG. 5 is a flowchart showing a detailed sequence of a subroutine “zoom enable” executed in step S8 of FIG. 4;

FIG. 6 is a flowchart illustrating a sequence on the camera body side according to the first embodiment.

FIG. 7 is an external configuration diagram of a second embodiment of the present invention.

FIG. 8 is a block diagram of a camera system employing a zoom lens and a camera according to a second embodiment of the present invention.

FIG. 9 illustrates L in the zoom lens 100 according to the second embodiment.
6 is a flowchart illustrating a lens sequence of the CPU 101.

FIG. 10 is a flowchart showing details of a sequence on the body side in the second embodiment.

FIG. 11 is a flowchart illustrating a lens sequence executed by an LCPU 101 in a zoom lens 100 according to a third embodiment.

FIG. 12 is a flowchart illustrating a sequence on the camera body side according to the third embodiment.

[Explanation of symbols]

 Reference Signs List 1 camera body 2 FCPU 3 4 1RSW 5 2RSW 6 exposure control section 7 film 50 camera body 51 DCPU 52 53 1RSW 54 2RSW 55 CCD driver 56 CCD 57 image processing circuit 58 image recording circuit 59 recording medium 60 exposure control section 100 zoom lens 101 LCPU 102 103 TELE SW 104 WIDE SW 105 Zoom motor 106 Zoom drive circuit 107 Zoom encoder 108 LD motor 109 LD motor drive circuit 110 LD encoder 111 Aperture mechanism 112 Stepper motor 113 Stepper motor drive circuit

Claims (3)

[Claims] 1. A zoom lens attachable to a camera, comprising: communication means for communicating with the camera and receiving data unique to the camera; and a camera based on data unique to the camera obtained by the communication means. A zoom lens comprising: a zoom range determining unit that determines a zoom range; and a zoom driving unit that performs zoom driving within a range of the zoom range determined by the zoom range determining unit. 2. A zoom lens attachable to a camera, comprising: communication means for communicating with the camera and receiving data unique to the camera; focal length detection means for detecting a set focal length; Based on data corresponding to the type of camera obtained by the communication unit and the focal length obtained by the focal length detection unit, a photographing availability determination unit that determines whether shooting is possible, and communicates with the camera to the camera. A transmission unit for outputting data indicating whether or not shooting is possible. And a communication unit for communicating with the zoom lens and receiving data unique to the zoom lens and data corresponding to a set focal length of the zoom lens. A camera comprising: a photographing possibility determination unit that determines photographing possibility according to data unique to the zoom lens and data corresponding to a focal length.