JP2993139B2 - Interchangeable lens and camera to wear it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens and a camera to which the interchangeable lens is mounted, and more particularly, to a photographic camera, a video camera and the like using a tilt lens, a shift lens, a tilt shift lens (TS lens), etc. The present invention relates to an interchangeable lens that compensates for fluctuations in photometric values obtained by photometric means provided on the camera body when tilting or shifting the camera so that an optimal exposure value is always obtained, and a camera to which the same is attached. is there.

[0002]

2. Description of the Related Art A camera provided with an automatic exposure control device for determining an optimal combination of a shutter speed and an aperture value from a photometric value, a film sensitivity, an AE mode, etc. obtained by a photometric means provided in a camera. Various proposals have been made.

FIG. 3 is a schematic view of a main portion of a conventional interchangeable lens, a photometric device provided in a camera to which the interchangeable lens is mounted, and an automatic exposure control device. In the figure, each element on the left side of the broken line indicates an objective lens side 301 as an interchangeable lens, and each element on the right side indicates a camera body side 302 as a camera.

On the objective lens side 301, reference numeral 1 denotes an objective lens, 2 denotes a focusing lens of the objective lens 1, 3 denotes an aperture, and 4 denotes an aperture drive control circuit.
The aperture drive is controlled based on the aperture drive amount sent from the printer and the state of the aperture 3. 5 is a lens data memory,
Data unique to the objective lens, such as the open / minimum F number and the focal length, are stored.

On the camera body 302 side, reference numeral 6 denotes a quick return mirror, and 7 denotes a submirror, which guides a light beam passing through a part of the quick return mirror 6 to a spot metering sensor 9. Reference numeral 8 denotes a pentaprism, and 10 denotes an average photometry sensor provided on the exit surface side of the pentaprism 8.

Reference numeral 11 denotes an eyepiece, and 12 denotes a microcomputer, which performs a photometric operation, an AE operation, and the like. Reference numeral 13 denotes film sensitivity reading means, and reference numeral 14 denotes AE mode setting means, which is used by a user to set how to determine a shutter speed and an aperture value.
Reference numeral 15 denotes a photometric method setting means for the user to set the photometric method. Reference numeral 16 denotes a shutter, and 17 denotes a shutter drive control circuit, which controls the drive of the shutter 16 by a shutter speed obtained from the microcomputer 12.

A drive end signal and an aperture drive amount are transmitted between the aperture drive control circuit 4 and the microcomputer 12 via connection terminals t _{1 to} t ₄ . From the lens data memory 5 to the microcomputer 12 transmits lens data Lens data output from the terminal t ₅ Lens data input terminal through t _6.

The microcomputer 12 reads the photometric value from the spot photometric sensor 9 or the average photometric sensor 10 in accordance with the photometric method set by the user by the photometric method setting means 15, and obtains the obtained photometric value and the film sensitivity reading means 13. Based on the film speed
According to the mode set by the user with the AE mode setting means 14, the shutter speed and the aperture value are calculated, and the calculated values are transferred to the shutter drive control circuit 17 and the aperture drive control circuit 4 and the shutter 16 and the aperture 3 are driven. Controlling timing.

A shutter drive control circuit 17 controls the drive time and timing of an actuator for driving the shutter 16 based on the shutter speed obtained from the microcomputer 12. When the driving is completed, a driving end signal is returned to the microcomputer 12. The aperture drive control circuit 4 controls the drive speed and the number of times of driving of the actuator for driving the aperture 3 based on the aperture value obtained from the microcomputer 12 and the state of the aperture 3. When the driving is completed, a driving end signal is returned to the microcomputer 12. The above is the basic exposure control operation.

Next, the photometric means will be described.

Light incident from the objective lens 1 is reflected by the quick return mirror 6 to form an object image on the surface of the focusing screen 24, and is further reflected by each reflecting surface of the pentaprism 8 to be reflected by the eyepiece 11.
Incident on. In the example of FIG. 3, the spot photometric sensor 9 is located below the sub-mirror 7, and the average photometric sensor 10 is located above the eyepiece 11 on the exit surface side of the pentaprism. Is detected and converted into an electrical signal.

FIGS. 4A and 4B show a tilt lens as an example of the objective lens 1 when it is fixed and when it is rotated (tilted) by a predetermined amount about a point on the optical axis of the focusing screen surface 24. Is shown. That is, the focusing screen 24 before and after the tilt, the eyepiece 11,
The relative positional relationship of the photometric sensors (average photometric sensor, spot photometric sensor, etc.) 25 and the optical system are shown.

In this example, the photometric sensor 25 is located above the eyepiece 11. In a normal state positioned as objective the figure (A), the angle between the optical axis of the optical axis and the photometric sensor 25 through the center of the objective lens 1 at that time is theta _1.

FIG. 2B shows a case where the objective lens 1 is tilted by a predetermined amount, and a case where a light beam passing through the objective lens 1 is incident on the photometric sensor 25 at 0 degree depending on the tilt direction, and is incident at θ ₂ degrees. Are respectively shown.

FIG. 5 shows the relationship between the angle .theta. Between the optical axis passing through the center of the objective lens 1 in FIG. 4 and the optical axis to the photometric sensor 25 and the amount of light L detected by the photometric sensor 25. is there. The closer the optical axis is to a right angle, the greater the amount of light passing therethrough, that is, the angle between the optical axis passing through the center of the objective lens 1 and the optical axis to the photometric sensor 25 as shown in FIG. Is designed to have such a characteristic that the smaller the is, the larger the amount of light can be obtained. The objective lens 1 is positioned at the position A in FIG.
, Since θ = θ ₁ , the photometric sensor 2
Amount L of 5 is detected becomes L = L ₁ As can be seen from FIG.

[0016]

In the conventional camera shown in FIG. 3, when the objective lens 1 tilts and moves from a normal position to a position B as shown in FIG. The optical axis to 25 coincides with the optical axis passing through the center of the objective lens 1 (θ = 0). Light amount detecting photometric sensor 25 from FIG. 5 this time would detect larger amount of light than L _3, and the amount of light L ₁ to be actually detected photometric sensor 25.

When the objective lens 1 is at the position C in FIG. 4B, the angle between the optical axis to the photometric sensor 25 and the optical axis passing through the center of the objective lens 1 is θ ₂ , light amount detecting photometric sensor 25 from FIG. 5 would detect the smaller amount than the amount L ₁ to be detected L _2, and the actual photometric sensor 25. If the objective lens 1 is displaced from the normal position as described above, it becomes impossible to detect a correct amount of light.

Although FIG. 1 shows a tilt lens as an example, the same applies to the case where a shift lens or a tilt shift lens (TS lens) is used.

Here, the shift lens is an objective lens which can move the optical axis of the taking lens in parallel.
It mainly enables correction of perspective. The tilt lens is an objective lens capable of tilting the optical axis of the photographing lens, and is capable of tilting a focusable imaging interface which is usually parallel to the film surface.

When such a shift lens or tilt lens is used as the objective lens 1 shown in FIG. 3, when no shift or tilt is performed, the spot metering sensor 9 is used.
In addition, since the average photometric sensor 10 can detect a correct light amount, no photometric error occurs. However, when shifting or tilting, the spot metering sensor 9
In addition, the angle formed between the optical axis to the average photometric sensor 10 and the optical axis passing through the center of the objective lens is smaller or larger than in the state without shifting or tilting.

If the photometry operation is performed carelessly in such a state, as shown in FIG.
In addition, since the average photometric sensor 10 detects a light amount larger or smaller than the actual light amount, a photometric error is caused, and in the worst case, there is a risk that a photograph whose exposure value is greatly out of order is taken. is there.

As a countermeasure, a shift lens or a tilt lens should not be included in a photographing lens series for a camera having an automatic exposure control device, or a conventional objective lens cannot be attached to the automatic exposure camera. Such a method can be considered.

However, this is extremely inconvenient when using a shift lens or a tilt lens because a manual exposure camera must be made easy in addition to an automatic exposure camera. Considering further development of the automatic exposure mechanism of the camera in the future, such a measure is not preferable. Also, most of the automatic exposure cameras can manually control the exposure by switching, and it is very inconvenient that such a shift lens or tilt lens cannot be used at all.

The present invention solves the above-mentioned problems, and an appropriate exposure value can be obtained even when a shift lens, a tilt lens, a TS lens, or the like is used as an objective lens. An object of the present invention is to provide a lens and a camera equipped with the lens.

[0025]

An interchangeable lens according to a first aspect of the present invention is an interchangeable lens that is detachable from a camera, and includes a translation amount of at least a part of a lens group constituting the interchangeable lens with respect to an optical axis. Detecting means for detecting at least one of the moving direction or the tilt amount with respect to the optical axis and the tilt direction, and the aperture value is determined based on the exposure correction information obtained using the detection result of the detecting means. It is characterized by. According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a lens data memory for storing the unique information of the interchangeable lens, and the unique information stored in the lens data memory and the detection of the detecting means. The aperture value is determined based on the exposure correction information obtained using the result. A camera according to a third aspect of the present invention is a camera to which the interchangeable lens according to the first or second aspect is mounted, comprising a photometric unit and a unit for obtaining the exposure correction information, wherein the photometric value obtained from the photometric unit is used as the camera. It is characterized in that correction is performed using exposure correction information.

In particular, in the embodiment of the present invention , one of the unique information of the interchangeable lens is information indicating that the interchangeable lens is a tilt lens or a shift lens or a tilt shift lens, and the interchangeable lens is The camera to which is attached has photometric value correcting means for correcting the photometric value obtained by the photometric means in the camera based on the unique information from the interchangeable lens and the detection result obtained by the detecting means. It is characterized by having. In addition to the above, in the present invention, means for detecting the amount of parallel movement of the optical axis of at least a part of the lens, means for detecting the direction of parallel movement of at least a part of the lens, Detecting means for detecting the amount of inclination of the optical axis, at least one or more detecting means for detecting the direction of inclination of the optical axis of at least some of the lenses, and an individual code indicating a tilt lens or a shift lens An individual code indicating which of the detection means is provided, an output means for outputting the information detected by the detection means and the individual code to the camera body, and a designation for designating information of the detection means from the camera body Means, and input means for inputting the designation information from the camera, and output means for sending a command or data to the interchangeable lens, and Input means for inputting data; determining means for determining that the mounted interchangeable lens is a tiltable or shiftable lens; and at least one of which uses a shift amount or inclination of an optical axis of the interchangeable lens as a parameter. A storage circuit for fixedly storing the exposure correction information corresponding to the above-described photometry method at each address, an address specifying circuit for specifying an address of the exposure correction information by a shift amount or a tilt amount of the optical axis of the interchangeable lens, The camera is provided with photometric value correction means for correcting the photometric value based on the correction information, and when it is detected that the interchangeable lens is in the shift or tilt state, the shift amount / direction or the tilt amount / direction is determined. Detection, and reads out predetermined exposure correction information based on the information and the photometry method, and corrects the exposure based on the exposure correction information, and always So that vertebral taken with exposure.

[0027]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention. FIG. 1 shows a case where a TS lens is used as an interchangeable lens (objective lens).

FIG. 2 is a flowchart showing the AE operation mode according to the first embodiment of the present invention. In FIG. 1, the same elements as those shown in FIG. 3 are denoted by the same reference numerals. In this embodiment, a case where a TS lens is used as an interchangeable lens is shown. However, there is an essential difference in applying the present invention to a shift lens or a tilt lens having only a shift mechanism or a tilt mechanism. However, the present invention can be similarly applied to a shift lens or a tilt lens.

Although the photometric sensor is shown as a spot photometric sensor and an average photometric sensor, the same applies to those having photometric sensors corresponding to other photometric methods.

In FIG. 1, reference numeral 1 denotes an objective lens, which in this embodiment is constituted by a TS lens. 2 is TS lens 1
, A tilt mechanism 18 of the TS lens 1, and 19 a tilt amount direction detecting means for detecting a tilt amount and a tilt direction of the tilt mechanism 18. Reference numeral 20 denotes a shift mechanism of the TS lens 1, and reference numeral 21 denotes a shift amount / direction detecting unit, which detects the shift amount and the shift direction of the shift mechanism 20.

The lens data memory 5 in this embodiment.
Stores data indicating whether the objective lens 1 is a shift lens, a tilt lens, or a TS lens, and data unique to the objective lens, such as a focal length and an F-number. Lens signal from the microcomputer 12 of the camera body 302 in the data memory 5 is inputted to the lens data specifying signal input terminal t ₁₁ through the lens data designation signal output terminal t _12.

The lens data memory 5 stores predetermined data from a lens data output terminal t ₅ to a lens data input terminal t ₆ based on a designated signal from the microcomputer 12.
Is input to the microcomputer 12 via the.

Reference numeral 22 denotes information designating means,
The detection mode of the detection means 26 is controlled in accordance with the detection command signal sent from the microcomputer 12 of FIG. That amount of tilt from the microcomputer 12 to the information specifying unit 22, tilt direction, the shift amount, the information specifying signal input terminal t ₇ from the signal indicating whether to specify which information of shift direction information designation signal output terminal t ₈ Transmitted via

Reference numeral 26 denotes a detecting means, and the information specifying means 22
Tilt amount / direction detecting means 1 based on a command signal from
9 and / or the shift / direction detecting means 21 is controlled. Then, the detecting means 26 outputs the information specified by the microcomputer 12 from the information of the tilt amount, the tilt direction, the shift amount and the shift direction obtained from the tilt amount / direction detecting means 19 and / or the shift amount / direction detecting means 21. The signal is output from the detection information output terminal t ₉ to the microcomputer 12 via the detection information input terminal t ₁₀ .

Reference numeral 23 denotes a storage circuit, which stores exposure correction information in which at least one exposure correction information corresponding to at least one or more photometric methods using the tilt amount, the tilt direction, the shift amount, and the shift direction as parameters is fixed. I remember.

The microcomputer 12 controls the exposure on the basis of information from the spot photometric sensor 9 or the average photometric sensor 10, the film sensitivity reading means 13, the AE mode setting means 14, and the photometric method setting means 15.

In this embodiment, in addition to these information, the exposure is controlled by adding exposure correction information based on the tilt amount, tilt direction, shift amount, and shift direction.

First, the microcomputer 12 reads the individual code from the lens data memory 5 and determines whether or not the mounted objective lens is a tilt lens, a shift lens or a TS lens by the discriminating means.
As a result, when it is determined that the mounted objective lens has the tilt mechanism or the shift mechanism or both, it is next determined whether the objective lens has the tilt amount / direction detecting means 19 or the shift amount / direction detecting means 21. The individual code is read out from the memory 5 for use in determination.

As a result, the tilt amount / direction detecting means 19
Alternatively, if the microcomputer 12 determines that it has the shift amount / direction detecting means 21 or both, the microcomputer 12 sets the tilt amount,
One or all of the tilt direction, the shift amount, and the shift direction are specified and output to the information specifying unit 22. The information designating unit 22 outputs the designated information to the detecting unit 26. The detecting means 26 drives the tilt amount / direction detecting means 19 or the shift amount / direction detecting means 21 based on the signal from the information specifying means 22, and outputs the data obtained from those detecting means to the detection information output terminal t _9. via the detection information input terminal t ₁₀ and outputs to the microcomputer 12.

The microcomputer 12 uses the information obtained in this way and the photometry system at that time to store the information in the storage circuit 2.
Address 2 is calculated, the exposure correction information stored at the calculated address is read from the storage circuit 22, and the exposure value obtained from the photometric value, film sensitivity, AE mode, etc. is corrected.

Next, the flowchart of FIG. 2 will be described. The microcomputer used here often controls, for example, a photometric system in addition to the AE operation, and only the AE operation will be described on the premise of this.

In FIG. 2, the control other than the AE operation
In operation, first, in step 1, lens data is read from the lens data memory 5. Here, the lens data is an individual code indicating that the lens is a tilt lens, a shift lens, or a TS lens, an individual code indicating whether the apparatus has a tilt amount / direction detecting unit, a shift amount / direction detecting unit, or both. It is a set of lens-specific data including a series.

Next, in step 2, the photometric method is read from the photometric method setting means 15. In the case of average photometry, the average photometric value is read from the average photometric sensor 10 in step 3, and in the case of spot photometry, in step 4, the spot photometric method is used. The spot metering value is read from the sensor 9. In step 5, the film sensitivity is read from the film sensitivity reading means 13.
In step 6, the AE mode is read from the AE mode setting means 14. In step 7, it is determined whether or not the lens is a shift lens based on the lens data read in step 1. If the lens is not a shift lens, the process proceeds to step 10. If it is a shift lens, it is determined in step 8 whether or not it has a shift amount / direction detecting means. If so, the shift amount / direction is read in step 9.

In step S10, it is determined whether or not the lens is a tilt lens based on the lens data read in step S1.
Proceed to. If it is a tilt lens, it is determined in step 11 whether or not it has a tilt amount / direction detecting means. If it is, the tilt amount / direction is read in step 12. In step 13, the photometric method read in step 2, the shift amount / direction read in step 9,
The address of the storage circuit 23 is calculated based on the tilt amount and direction read in step 12.

In step 14, the exposure correction information stored at the address obtained in step 13 is read from the storage circuit 23. In step 15, the shutter speed is determined from the photometric method read in step 2, the photometric value read in step 3 or step 4, the film sensitivity read in step 5, the AE mode read in step 6, the exposure correction value read in step 14, and the like. Calculate aperture values, display them in step 16, and set AE
The operation is terminated, and control is shifted to a control other than the AE operation.

According to the present embodiment, a shift lens, a tilt lens, a TS lens, and the like can be mounted on a camera having an automatic exposure control device, and the photometric sensor detects an incorrect photometric value due to the shift or tilt. Also in this case, the exposure value is corrected based on the information of the shift amount / direction and the tilt amount / direction, so that a photograph can always be taken with the correct exposure.

The storage circuit 23 for fixing the exposure correction information
May be an arithmetic circuit that calculates an exposure correction value from the shift amount / direction, the tilt amount / direction, and the photometry method.

[0048]

According to the present invention, the interchangeable lens mounted on the camera body is a shift lens, a tilt lens or a T lens.
An S lens, an interchangeable lens that always obtains an appropriate exposure value by setting each element as described above and correcting the photometric value obtained from the photometric means even if a predetermined shift or tilt is performed, and A wearing camera can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a flowchart of the first embodiment of the present invention.

FIG. 3 is a schematic view of a main part when a conventional interchangeable lens is mounted on a camera body.

FIG. 4 is an explanatory diagram showing a positional relationship and an optical system of an interchangeable lens, a focusing screen, an eyepiece, and a photometric sensor.

FIG. 5 is an explanatory diagram showing a relationship between an angle formed between an optical axis passing through the center of the interchangeable lens and an optical axis to a photometric sensor, and a light amount detected by the photometric sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Focusing lens 3 Aperture 4 Aperture drive control circuit 5 Lens data memory 6 Click return mirror 7 Submirror 8 Pentaprism 9 Spot photometry sensor 10 Average photometry sensor 11 Eyepiece lens 12 Microcomputer 13 Film sensitivity reading means 14 AE Mode setting means 15 Metering method setting means 16 Shutter 17 Shutter drive control circuit 18 Tilt mechanism 19 Tilt amount / direction detecting means 20 Shift mechanism 21 Shift amount / direction detecting means 22 Information designating means 23 Storage circuit 24 Focusing screen 25 Photometric sensor 26 detecting means t ₁ ~t ₄ stop data transmission connection terminal t ₅ lens data output terminal t ₆ Lens data input terminal t ₇ information specifying signal input terminal t ₈ information designation signal output terminal t ₉ detection information output terminal t ₁₀ detects information input terminal t ₁₁ lens data specifying signal input terminal t ₁₂ Lens data designation signal output terminal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-197926 (JP, A) JP-A-2-79808 (JP, A) JP-A-62-227108 (JP, A) 100218 (JP, U) JP-A 2-55212 (JP, U) JP-A 60-133435 (JP, U) JP-A 63-120236 (JP, U) JP-B 47-20729 (JP, B1) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 7/20 G03B 5/00

Claims (3)

(57) [Claims] 1. An interchangeable lens which is detachable from a camera.
And at least a part of lens groups constituting the interchangeable lens
The amount of parallel movement with respect to the optical axis and its moving direction, or
At least one of the amount of tilt and the direction of tilt is detected
Detecting means using the detection result of the detecting means.
Note that the aperture value is determined based on the
Interchangeable lens 2. An apparatus according to claim 1, wherein the information unique to said interchangeable lens is stored.
A lens data memory, and a lens data memo.
And the detection result of the detection means
The aperture value is determined based on the exposure compensation information obtained using
The interchangeable lens according to claim 1, wherein 3. An interchangeable lens according to claim 1 or 2,
A camera for determining photometric means and the exposure compensation information.
Means for measuring the photometric value obtained from the photometric means.
A camera that performs correction using exposure correction information.
La.