JPH04240833A - Interchangeable lens and camera attached with the lens - Google Patents

Abstract

PURPOSE:To obtain an interchangeable lens for obtaining an optimum exposure value and a camera on which the interchangeable lens is attached by correcting a photometric value obtained on a camera main body side based on the information of a tilting quantity and a shifting quantity at this time, when a tilt lens, a shift lens, a TS lens, etc., are attached on a camera main body, and tilted and shifted. CONSTITUTION:A detecting means 26, at least, detecting one of the quantity and direction of moving in parallel to the optical axis of a part of a lens group constituting the interchangeable lens 301, and the quantity and direction of an inclination with respect to the optical axis, memory 5 storing the proper information of the interchangeable lens 301, and an information specifying means 22 controlling the detection mode of the detecting means 26 in response to a detection commanding signal from the side of the camera 302, based on the proper information stored in the memory 5, are provided. The detecting means 26 carries out a prescribed detection based on a signal from the information specifying means 22, and the detection result is outputted to the side of the camera.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an interchangeable lens and a camera equipped with the same, and particularly to a photographic camera, a video camera, etc., in which a tilt lens, a shift lens, a tilt-shift lens (TS lens), etc. are used as interchangeable lenses. This lens relates to an interchangeable lens that compensates for fluctuations in the photometric value obtained by the photometric means installed on the camera body when tilting or shifting, so that the optimum exposure value can always be obtained, and the camera to which it is attached. be.

0002

2. Description of the Related Art Conventionally, cameras are equipped with an automatic exposure control device that determines the optimal combination of shutter speed and aperture value based on photometric values obtained by a photometric means installed in the camera, film sensitivity, AE mode, etc. Various proposals have been made.

FIG. 3 is a schematic diagram of main parts of a conventional interchangeable lens and a photometer and automatic exposure control device provided in a camera to which the interchangeable lens is attached. In the figure, each element on the left side of the broken line represents an objective lens side 301 as an interchangeable lens, and each element on the right side represents a camera body side 302 as a camera.

On the objective lens side 301, 1 is an objective lens, 2 is a focusing lens for the objective lens 1, 3 is an aperture, 4 is an aperture drive control circuit, and the camera body 302
The aperture drive is controlled based on the aperture drive amount and the state of the aperture 3 sent from the aperture. 5 is a memory for lens data;
Data specific to the objective lens, such as aperture/minimum F number and focal length, is stored.

On the side of the camera body 302, 6 is a quick return mirror, and 7 is a submirror, which guides the light beam that has passed through a part of the quick return mirror 6 to a spot photometry sensor 9. 8 is a pentaprism, and 10 is an average photometry sensor, which is provided on the exit surface side of the pentaprism 8.

Reference numeral 11 is an eyepiece lens, and 12 is a microcomputer, which performs photometry operations, AE operations, and the like. 13 is a film sensitivity reading means, and 14 is an AE mode setting means, which is used by the user to set how the shutter speed and aperture value are to be determined. Reference numeral 15 denotes a photometry method setting means, which is used by the user to set the photometry method. 16 is a shutter, and 17 is a shutter drive control circuit, which drives and controls the shutter 16 based on the shutter speed obtained from the microcomputer 12.

A drive end signal and the amount of aperture drive are transmitted between the aperture drive control circuit 4 and the microcomputer 12 via connection terminals t1 to t4. Lens data is transmitted from the lens data memory 5 to the microcomputer 12 via a lens data output terminal t5 and a lens data input terminal t6.

The microcomputer 12 reads the photometric value from the spot photometry sensor 9 or the average photometry sensor 10 according to the photometry method set by the user by the photometry method setting means 15, and reads the obtained photometry value and the film sensitivity reading means 13. Based on the obtained film sensitivity,
The AE mode setting means 14 calculates the shutter speed, aperture value, etc. according to the mode set by the user, transfers the calculated values to the shutter drive control circuit 17 and the aperture drive control circuit 4, and drives the shutter 16 and the aperture 3. It controls the timing.

The shutter drive control circuit 17 controls the driving time and timing of the 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 sent back to the microcomputer 12. Further, the aperture drive control circuit 4 controls the driving speed and 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 sent back to the microcomputer 12. The above is the basic exposure control operation.

Next, the photometric means will be explained.

The light incident from the objective lens 1 is reflected by the quick return mirror 6 to form an object image on the focusing screen 24, and further reflected by each reflecting surface of the pentaprism 8 to the eyepiece 11.
incident on . In the example shown in FIG. 3, the spot photometry sensor 9 is located below the sub-mirror 7, and the average photometry sensor 10 is located above the eyepiece 11 on the exit surface side of the pentaprism. It detects the noise and converts it into an electrical signal.

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

In this example, the photometric sensor 25 is located above the eyepiece 11. In a normal state, the objective lens is positioned as shown in FIG. 2A, and the angle between the optical axis passing through the center of the objective lens 1 and the optical axis toward the photometric sensor 25 is θ1.

FIG. 2B shows cases where, when the objective lens 1 is tilted by a predetermined amount, the light beam passing through the objective lens 1 is incident on the photometric sensor 25 at 0 degrees and at θ2 degrees depending on the tilt direction. Each is shown.

FIG. 5 shows the relationship between the angle θ formed by the optical axis passing through the center of the objective lens 1 and the optical axis to the photometric sensor 25 in FIG. 4 and the amount of light L detected by the photometric sensor 25. be. The focusing screen 24 is designed so that the closer the optical axis is to a right angle, the greater the amount of light passing through it. In other words, as shown in FIG. It is designed to have a characteristic that the smaller the value, the greater the amount of light that can be obtained. When the objective lens 1 is at position A in FIG. 4(A), θ=θ1, so the photometric sensor 2
As can be seen from FIG. 5, the amount of light L detected by 5 is L=L1
becomes.

[0016]

[Problems to be Solved by the Invention] In the conventional camera shown in FIG. 3, when the objective lens 1 tilts and moves from its normal position to position B as shown in FIG. 4(B), the photometry sensor The optical axis to 25 and the optical axis passing through the center of the objective lens 1 coincide (θ=0). At this time, as shown in FIG. 5, the amount of light detected by the photometric sensor 25 is L3, which is larger than the amount of light L1 that the photometric sensor 25 should actually detect.

When the objective lens 1 is at position C in FIG. 4(B), 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 θ2, and 5
Therefore, the amount of light detected by the photometric sensor 25 is L2, which is smaller than the amount of light L1 that the photometric sensor 25 should actually detect. If the objective lens 1 is displaced from its normal position in this way, it becomes impossible to detect the correct amount of light.

Although the figure 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.

[0019] Here, the shift lens is an objective lens that can move the optical axis of the photographing lens in parallel.
It mainly enables correction of perspective. A tilt lens is an objective lens that can tilt the optical axis of the photographic lens, and makes it possible to tilt the surface of the object that can be focused, which is usually parallel to the film plane.

When such a shift lens or tilt lens is used as the objective lens 1 in FIG. 3, the spot photometry sensor 9
Since the average photometry sensor 10 can detect the correct amount of light, no photometry error occurs. However, when shifted or tilted, the spot metering sensor 9
Also, the angle formed between the optical axis to the average photometry sensor 10 and the optical axis passing through the center of the objective lens becomes smaller or larger than when no shift or tilt is performed.

If photometry is performed carelessly in such a state, the spot photometry sensor 9 will be damaged as shown in FIG.
Since the average light metering sensor 10 detects a light amount that is larger or smaller than the actual light amount, it may cause a photometry error, and in the worst case, there is a risk of taking a photograph with a greatly incorrect exposure value. be.

As a countermeasure, either shift lenses or tilt lenses should not be included in the photographic lens series for cameras equipped with automatic exposure control devices, or conventional objective lenses cannot be attached to automatic exposure cameras. There are ways to devise ways to do this.

However, when using a shift lens or a tilt lens, it is necessary to use a manual exposure camera in addition to an automatic exposure camera, which is extremely inconvenient. Considering the further development of automatic exposure mechanisms of cameras in the future, such countermeasures are by no means preferable. Moreover, even though they are automatic exposure cameras, most of them allow manual exposure control by switching, and it is very inconvenient that such shift lenses and tilt lenses cannot be used at all.

[0024] The present invention solves the above-mentioned problems, and even when a shift lens, tilt lens, TS lens, etc. is used as an objective lens, an appropriate exposure value can be obtained, and good photographs can always be taken. The purpose is to provide lenses and cameras to which they are attached.

[0025]

[Means for Solving the Problems] The interchangeable lens of the present invention includes:
An interchangeable lens that is detachably attached to a camera and used, the interchangeable lens includes an output means for outputting unique information of the interchangeable lens to the camera to which it is attached, and at least a part of the lenses constituting the interchangeable lens. detection means for detecting at least one of the amount of parallel movement of the group with respect to the optical axis and the direction at that time, and the amount of inclination with respect to the optical axis and the direction at that time;
A lens data memory that stores unique information of the interchangeable lens; and a detection mode of the detection means in response to a detection command signal sent from the camera based on the unique information stored in the lens data memory. and information specifying means for controlling the information specifying means, and the detecting means performs predetermined detection based on the signal from the information specifying means and outputs the detection result to the camera side. .

Particularly, in the present invention, one of the unique information of the interchangeable lens is information indicating that the interchangeable lens is a tilt lens, a shift lens, or a tilt shift lens, and when the interchangeable lens is attached. The camera has photometric value correction 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 detection means. It is a feature. In addition, the present invention includes means for detecting the amount of parallel movement of the optical axis of at least some of the lenses, means for detecting the direction of parallel movement of at least some of the lenses, and means for detecting the direction of parallel movement of at least some of the lenses. at least one or more of the following: a means for detecting the amount of inclination of the optical axis; a means for detecting the direction of inclination of the optical axis of at least some of the lenses; and an individual code indicating that the lens is a tilt lens or a shift lens. , an individual code indicating which of the detection means it has, an output means for outputting the information detected by the detection means and the individual code to the camera body, and a designation for specifying the information of the detection means from the camera body. and an input means for inputting the specified information from the camera, an output means for sending commands or data to the interchangeable lens, an input means for inputting data from the interchangeable lens, and an input means for inputting the specified information from the camera, and an input means for inputting data from the interchangeable lens. , or a determination means for determining whether the lens is shiftable, and exposure compensation information corresponding to at least one photometry method using the amount of deviation or tilt of the optical axis of the interchangeable lens as a parameter is fixed to each address. a storage circuit for storing the information; an addressing circuit for specifying the address of the exposure correction information based on the amount of deviation or inclination of the optical axis of the interchangeable lens; and a photometric value correction means for correcting the photometric value based on the exposure correction information. If it is detected that the interchangeable lens is in a shifted or tilted state, the amount and direction of shift or the amount and direction of tilt is detected, and a certain predetermined exposure is determined based on the information and the photometry method. The correction information is read out and the exposure is corrected based on the exposure correction information, so that images are always taken with the correct exposure.

[0027]

Embodiment FIG. 1 is a schematic diagram of a main part of Embodiment 1 of the present invention. The figure 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 of the first embodiment of the present invention. In FIG. 1, the same elements as those shown in FIG. 3 are given the same reference numerals. Although this example shows a case where a TS lens is used as an interchangeable lens, there are essential differences in applying the present invention to a shift lens or a tilt lens that only has either a shift mechanism or a tilt mechanism. However, it can be similarly applied to shift lenses or tilt lenses.

Regarding the photometric sensors, a spot photometric sensor and an average photometric sensor are shown, but the same applies to photometric sensors according to other photometric methods.

In FIG. 1, 1 is a TS lens, 2 is a focusing lens of the TS lens 1, 18 is a tilt mechanism of the TS lens 1, 19 is a tilt amount direction detecting means,
The tilt amount and tilt direction of the tilt mechanism 18 are detected. 20 is a shift mechanism of the TS lens 1, and 21 is a shift amount/direction detecting means, which detects the shift amount and shift direction of the shift mechanism 20.

Lens data memory 5 in this embodiment
Stored in the field are data indicating whether the objective lens 1 is a shift lens, tilt lens, or TS lens, and unique data such as the focal length and F number of the objective lens. The lens data memory 5 receives a signal from the microcomputer 12 of the camera body 302 via the lens data designation signal output terminal t12 and then enters the lens data designation signal input terminal t1.
1 is input.

The lens data memory 5 transfers predetermined data from the lens data output terminal t5 to the lens data input terminal t based on a designated signal from the microcomputer 12.
6 and is input to the microcomputer 12.

[0033] 22 is an information specifying means, and the camera body 3
The detection mode of the detection means 26 is controlled according to the detection command signal sent from the microcomputer 12 of 02. That is, the information specifying means 22 receives a signal from the microcomputer 12 from the information specifying signal output terminal t8 to the information specifying signal input terminal t7, indicating which information to specify among the tilt amount, tilt direction, shift amount, and shift direction.
It is transmitted via

26 is a detection means, and information specifying means 22
Tilt amount/direction detection means 1 based on a command signal from
9 and/or shift amount/direction detection means 21. The detection means 26 detects information specified by the microcomputer 12 from among the information on the tilt amount, tilt direction, shift amount, and shift direction obtained from the tilt amount/direction detection means 19 and/or the shift amount/direction detection means 21. The detected information is output from the detected information output terminal t9 to the microcomputer 12 via the detected information input terminal t10.

Reference numeral 23 denotes a memory circuit, which fixes exposure compensation information that is fixedly stored in each address according to at least one or more photometry methods using tilt amount, tilt direction, shift amount, and shift direction as parameters. I remember.

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

In this embodiment, in addition to these pieces of information, exposure correction information based on the tilt amount, tilt direction, shift amount, and shift direction is also added to control the exposure.

First, the microcomputer 12 reads an individual code from the lens data memory 5 and uses a determining means to determine whether the attached objective lens is a tilt lens, a shift lens, or a TS lens. As a result, if it is determined that the attached objective lens has a tilt mechanism, a shift mechanism, or both, the lens data is then determined as to whether it has a tilt amount/direction detection means 19 or a shift amount/direction detection means 21. The individual code is read out from the memory 5 for judgment.

As a result, the tilt amount/direction detection means 19
Alternatively, if the microcomputer 12 determines that it has the shift amount/direction detection means 21 or both, the microcomputer 12 determines the tilt amount,
Any or all of the tilt direction, shift amount, and shift direction is specified and output to the information specifying means 22. The information specifying means 22 outputs the specified information to the detecting means 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 sends the data obtained from these detecting means to the detected information output terminal t9. The detected information is output to the microcomputer 12 via the input terminal t10.

The microcomputer 12 uses the information thus obtained and the photometry method at that time to store the information in the memory circuit 2.
The exposure correction information stored in the calculated address is read out from the storage circuit 22, and correction is applied to the exposure value obtained from the photometric value, film sensitivity, AE mode, etc.

Next, the flowchart shown in FIG. 2 will be explained. In addition to the AE operation, the microcomputer used here often controls, for example, a photometric system, so only the AE operation will be described on the premise that this is the case.

In FIG. 2, from control other than AE operation
Moving on to the operation, first in step 1, lens data is read from the lens data memory 5. Here, the lens data includes an individual code indicating that it is a tilt lens, a shift lens, or a TS lens, and an individual code indicating whether it has a tilt amount/direction detection means, a shift amount/direction detection means, or both. This is a set of data specific to a series of lenses.

Next, in step 2, the photometry method is read from the photometry method setting means 15, and in the case of average photometry, the average photometry value is read from the sensor 10 for average photometry in step 3, and in the case of spot photometry, the value for spot photometry is read in step 4. Read the spot photometry value from 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 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 shift amount/direction detection means, and if so, the shift amount/direction is read in step 9.

In step 10, it is determined whether the lens is a tilt lens based on the lens data read in step 1, and if it is not a tilt lens, step 13 is performed.
Proceed to. If it is a tilt lens, it is determined in step 11 whether or not it has a tilt amount/direction detection means, and if so, the tilt amount/direction is read in step 12. In step 13, the photometry method read in step 2, the shift amount and direction read in step 9,
The address of the memory 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 determined in step 13 is read from the storage circuit 23. In step 15, the shutter speed is determined from the photometry method read in step 2, the photometry value read in step 3 or step 4, the film sensitivity read in step 5, the AE mode read in step 6, the exposure compensation value read in step 14, etc.・Calculate the aperture value, display them in step 16, and set the AE
Abort the operation and shift to control other than AE operation.

According to this embodiment, it is possible to attach a shift lens, a tilt lens, a TS lens, etc. to a camera equipped with an automatic exposure control device, and the photometry sensor detects an incorrect photometry value due to shift or tilt. Even in such cases, the exposure value is corrected based on information about shift amount and direction and tilt amount and direction, so you can always take photos with the correct exposure.

Note that the memory circuit 23 fixes the exposure compensation information.
may be an arithmetic circuit that calculates the exposure correction value from the shift amount/direction, tilt amount/direction, and photometry method.

[0048]

Effects of the Invention According to the present invention, the interchangeable lens attached to the camera body is a shift lens, a tilt lens, or a T lens.
This is an interchangeable lens that is an S lens, and allows you to always obtain an appropriate exposure value by setting each element as described above and correcting the photometric value obtained from the photometer, even if you perform a predetermined shift or tilt. It can be achieved by attaching a camera.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the main parts of Example 1 of the present invention.

FIG. 2 is a flowchart diagram of Embodiment 1 of the present invention.

[Fig. 3] A schematic diagram of the main parts when a conventional interchangeable lens is attached to a camera body.

[Figure 4] Interchangeable lenses, focusing screen,
FIG. 2 is an explanatory diagram showing the positional relationship between an eyepiece lens, a photometric sensor, and an optical system.

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

[Explanation of symbols]

1 Objective lens 2
Focusing lens 3 aperture
4 Aperture drive control circuit 5 Lens data memory
6 Click return mirror 7 Sub mirror 8
Pentaprism 9 Spot photometry sensor 10
Average photometry sensor 11 Eyepiece 12
Microcomputer 13 Film sensitivity reading means 14 AE mode setting means 15 Photometry method setting means 16 Shutter 17 Shutter drive control circuit 18 Tilt mechanism 19 Tilt amount/direction detection means 20 Shift mechanism 21
Shift amount/direction detection means 22 Information specification means 23 Memory circuit 24 Focusing screen 25 Photometry sensor 26 Detection means t1 to t4 Aperture data transmission connection terminal t5
Lens data output terminal t6 Lens data input terminal t7 Information designation signal input terminal t8 Information designation signal output terminal

Claims (3)

[Claims] 1. An interchangeable lens that is used while being detachably attached to a camera, the interchangeable lens comprising an output means for outputting unique information of the interchangeable lens to the camera to which the interchangeable lens is attached; a detection means for detecting at least one of the amount of parallel movement of at least some of the lens groups with respect to the optical axis and the direction at that time, and the amount of inclination with respect to the optical axis and the direction at that time; storing unique information of the interchangeable lens; and information specifying means for controlling the detection mode of the detection means in response to a detection command signal sent from the camera side based on the unique information stored in the lens data memory. An interchangeable lens characterized in that the detection means performs predetermined detection based on the signal from the information designation means and outputs the detection result to the camera side. 2. The interchangeable lens according to claim 1, wherein one of the unique information of the interchangeable lens is information indicating that the interchangeable lens is a tilt lens, a shift lens, or a tilt shift lens. 3. A camera to which the interchangeable lens is attached,
The camera is characterized by comprising a photometric value correction 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 detection means. camera.