JP2008233746A - Lens-interchangeable camera with stop value controller, and interchangeable lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens-interchangeable camera with an stop value controller which can correct the errors of stopping amont or the errors of actual stop value due to a mechanical factor, or the like of an interchangeable lens, and to provide the interchangeable lens. <P>SOLUTION: The lens-interchangeable camera includes an stop value control means which controls the interchangeable lens stopping device which performs opening/closing operations of an aperture in accordance with the movement of an aperture lever by a movement amount of the aperture lever; and a storage means, wherein the correction data for correcting aperture errors due to mechanical elements of the interchangeable lens is stored. The correction data corrects an aperture control value for controlling the moved amount of the aperture lever so that the stop value set in the camera agrees with an actual stop value of the aperture device which is controlled on the basis of the stop value by the aperture level of the stop value control means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an interchangeable lens camera and an interchangeable lens provided with an aperture value control device capable of correcting an aperture value.

  Conventionally, in an aperture control mechanism of a lens interchangeable camera, the aperture mechanism of the interchangeable lens operates following the movement of the aperture lever of the camera body, and the aperture of the aperture mechanism in the interchangeable lens is determined by the stop position of the aperture lever. It was a mechanism. Thus, this diaphragm control mechanism is a so-called equidistant position control method in which the movement amount of the diaphragm lever and the change in the diaphragm value are set to be linear. Thus, conventionally, in order to increase the accuracy of the equidistant position control, a device such as a governor is provided so that the moving speed of the aperture lever is constant.

However, in recent years, due to the downsizing of the imaging screen, the influence of dimensional errors and the like of a plurality of aperture driving parts in the interchangeable lens has increased, and the linear relationship has collapsed, and aperture errors often occur. FIG. 8A is a graph showing an error between the aperture value Av controlled by the aperture lever and the actual aperture value Av of the aperture when the movement amount of the aperture lever and the aperture value change are nonlinear. Therefore, an invention has been proposed in which exposure correction data for correcting such an aperture error is stored in a storage unit of an interchangeable lens and transmitted to a camera body at the time of photographing (Patent Document 1). FIG. 8B is a graph showing the relationship between the correction amount corrected by the exposure correction data and the aperture value.
Further, since the moving speed of the aperture lever is deviated from the design value, an error may occur between the timing at which the aperture lever is locked and the actual locking position. FIG. 8C is a graph showing the relationship between the set aperture value and the actual aperture value error that occur in such a case.
JP 2000-206585 A

  However, the prior art eventually corrects the exposure value, and the calculated aperture value or shutter speed differs from the actually controlled aperture value or shutter speed. In recent digital single-lens reflex cameras, high precision is also required regarding the aperture. The more the interchangeable lens with a smaller image sensor area and shorter focal length is attached, the greater the effect on the image due to the error in the actual aperture value. It has been desired that the actual aperture value and the aperture opening / closing degree exactly match.

  The present invention has been made in view of such a conventional problem, and an interchangeable lens camera including an aperture value control device capable of correcting an aperture amount error or an actual aperture value error due to mechanical factors of an interchangeable lens, and the like. An object is to provide an interchangeable lens.

  The present invention that achieves the above object is a lens-replaceable camera that is detachable from a lens, and an aperture value that controls an aperture device of an interchangeable lens that opens and closes the aperture in conjunction with movement of the aperture lever by controlling the amount of movement of the aperture lever. Control means, and storage means for storing correction data for correcting aperture errors caused by mechanical elements of the interchangeable lens, the correction data being based on the aperture value set in the camera and the aperture value. The present invention is characterized in that the correction data corrects an aperture control value for controlling the movement amount of the aperture lever so that the actual aperture value of the aperture device controlled by the aperture lever of the aperture value control means matches.

  Actually, in the interchangeable lens camera provided with the aperture value control device of the present invention, the aperture lever moves in the aperture direction from the open position, and the movement amount is controlled as a plurality of stages.

  In a preferred embodiment, the correction data stored in the storage means is a unit correction per 1 Ev and the number of steps N required for the diaphragm lever to move from the open position to the Avs value of the reference diaphragm that is a reference for correction. The amount was set as K. The aperture value control means calculates a correction amount for correcting the aperture control value by the equation: (Avs + N−Av) × K.

  In another preferred embodiment, the correction data stored in the storage means is corrected from the open position by the number of steps N required for the diaphragm lever to move from the open position to the Avs value of the reference diaphragm that is the reference for correction. The unit correction amount KE per 1 Ev is within the aperture value range up to the Avs value of the reference aperture that is the reference of 1 Ev, and 1 Ev within the aperture value range from the Avs value of the reference aperture that is the reference of the correction to the Av value of the minimum aperture. Per unit correction amount KS. Then, the aperture value control means calculates the correction amount for correcting the aperture control value by the formula (Avs + N−Av) × KS in the aperture value range from the open state to the reference aperture Avs value. From the Avs value to the minimum aperture value is calculated by the equation: (Avs + N−Av) × KE.

  In still another preferred embodiment, the correction data stored in the storage means is the open aperture value Avo, and the correction coefficient for the acceleration interval from the open position to the first reference value D1 at which the aperture lever accelerates is Ks1. , The correction constant is C1, the correction coefficient for the constant speed section from the first reference value D1 to the second reference value D2 at which the aperture lever moves at a constant speed is Ks2, the correction constant is C2, and the second is that the aperture lever is decelerated. The correction coefficient for the deceleration zone from the reference value D2 to the minimum aperture is set as Ks3, and the correction constant is set as C3. Then, the Av value of the reference diaphragm serving as the reference is set to the open diaphragm Avs value, the diaphragm value control means calculates the correction amount, and, when the diaphragm value Av to be controlled is less than D1, the equation is (Ks1 × Av + When the aperture value Av to be controlled is greater than or equal to D1 and less than D2, according to (C1), the equation is (Ks2 × Av + C2). When the aperture value Av to be controlled is greater than or equal to D2, the equation is: Calculate by

  The present invention relating to an interchangeable lens is an interchangeable lens of an interchangeable lens camera, and an aperture device whose aperture is controlled by the amount of movement of the aperture lever of the camera, and an aperture error caused by mechanical elements of the interchangeable lens Storage means for storing correction data, and the correction data matches the aperture value set in the camera with the actual aperture value of the aperture device controlled by the aperture lever of the camera based on the aperture value. As described above, the present invention is characterized in that it is correction data for correcting an aperture control value for controlling the movement amount of the aperture lever.

  In a preferred embodiment, the correction data stored in the storage means includes the number of steps N required for the diaphragm lever to move from the open position to the Av value of the reference diaphragm that serves as a correction reference, and the unit correction amount per 1 Ev. K.

  In another preferred embodiment, the correction data stored in the storage means includes the number N of steps required for the diaphragm lever to move from the open position to the Av value of the diaphragm that is a reference for correction, and the correction data from the open position. Within the aperture value range up to the Av value of the reference reference aperture, the unit correction amount KE per 1 Ev, and per Ev within the aperture value range from the Av value of the reference aperture that is the reference of the correction to the Av value of the minimum aperture Unit correction amount KS.

  In still another preferred embodiment, the correction data stored in the storage means includes the open aperture value as Avo, and the correction coefficient for the acceleration interval from the open position to the first reference value D1 at which the aperture lever accelerates as Ks1. , The correction constant is C1, the correction coefficient for the constant speed section from the first reference value D1 to the second reference value D2 at which the aperture lever moves at a constant speed is Ks2, the correction constant is C2, and the second is that the aperture lever is decelerated. The correction coefficient for the deceleration zone from the reference value D2 to the minimum aperture is set as Ks3, and the correction constant is set as C3.

As described above, according to the present invention, since the interchangeable lens stores correction data for correcting the aperture amount so that the set aperture value can be obtained, the correction data is read out and the actual aperture value to be controlled The error with the aperture value (diaphragm aperture) of the aperture device can be reduced.
Further, according to the present invention, even when the linear relationship between the aperture amount and the aperture value is broken and a mountain-shaped or valley-shaped aperture error is generated with reference to a certain aperture value, the correction data corresponding thereto is stored in the lens. Thus, the correction data can be read by the camera, and the error between the aperture value to be controlled and the aperture value of the actual aperture device can be reduced.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of an external appearance of an embodiment of a camera body 10 of an interchangeable lens camera equipped with an aperture value control device of the present invention. A lens mount 3 for attaching / detaching the interchangeable lens 100 is provided on the front surface of the camera body 10, and a main switch lever 37, a shutter button 39, an electronic dial 45a, a mode setting dial 45b, and an external LCD 41 for displaying information are provided on the upper part. Etc. are arranged. A finder window, a monitor LCD, and the like are disposed on the back. A diaphragm lever 61 that moves in the vertical direction is provided in the mount 51. The aperture lever 61 abuts on the aperture interlocking rod of the mounted interchangeable lens 100 and normally maintains the aperture of the interchangeable lens in an open state. Move to a position to narrow down to the value. Reference numeral 71 denotes a mirror, and FIG. 1 is in a state of being lowered to the observation position.

  FIG. 2 is a block diagram showing an embodiment of the main configuration of the control system related to aperture control mounted on the camera body 10. The control system mounted on the camera body 10 is composed of a CPU 11 and a DPU 13 connected to each other via a bus line. The CPU 11 and the DPU 13 are control means that collectively control the entire system of the camera body 10. It has the function of The DPU 13 is connected to a lens CPU 101 mounted on the interchangeable lens 100, and the CPU 11 communicates with the lens CPU 101 via the DPU 13.

  The interchangeable lens 100 further includes a lens memory 103 in which lens information is written. The lens CPU 101 reads lens information from the lens memory 103 and uses it for control. This lens information includes information related to correction of the aperture value of the aperture stop device 110 in addition to known information related to the lens function.

  A peripheral circuit such as a photometric IC 15 and a DC / DC converter 21 and an operation unit 45 are connected to the DPU 13, and the CPU 11 controls the peripheral circuit via the DPU 13. The photometry IC 15 inputs an electrical signal photoelectrically converted according to the amount of received light to the CPU 11 via the DPU 13 as a photometry signal (subject brightness Bv). The CPU 11 calculates a proper exposure value Ev, a proper shutter speed Tv, and an aperture value Av by executing a predetermined exposure calculation (AE calculation) based on the input subject brightness Bv, ISO sensitivity Sv, and the like. Further, in the present embodiment, an EE pulse corresponding to the calculated aperture value Av is also calculated. Here, the EE pulse is a pulse output by the aperture control photo interrupter 29 in conjunction with the aperture operation of the aperture mechanism 60 (FIG. 2). The aperture value can be controlled by counting the number of EE pulses and stopping the narrowing mechanism 60. In the camera body 10, the number of EE pulses is an aperture control value.

  The DC / DC converter 21 is connected to the DPU 13 and a battery (not shown). When the power control signal output from the CPU 11 is input via the DPU 13, the DC / DC converter 21 is supplied to the aperture control photo interrupter 29, the in-finder LCD 43, the external LCD, and the like. Supply power. The operation unit (switch unit) 45 includes switches for selecting each function and mode of the camera, such as setting of an exposure mode. The DPU 13 changes the state of the camera body 10 according to each switch information input from the operation unit 45. Set.

  The DPU 13 communicates with the lens CPU 101 mounted on the interchangeable lens 100 via the electrical contact group provided on the mount surface. The lens CPU 101 is connected to a memory that stores lens information unique to the photographing lens, such as focal length information, full aperture value, and minimum aperture value information. These pieces of shooting information are read into the DPU 13 by communication with the camera body. The DPU 13 transmits the lens information read by communication with the lens CPU 101 to the CPU 11 by communication executed with the CPU 11.

  The CPU 11 includes a ROM 11a in which a program related to camera functions and the like are written, and a RAM 11b that temporarily stores various parameters, lens information, and the like. The CPU 11 inputs the lens information including the aperture value correction information of the interchangeable lens 100 and the subject luminance Bv detected by the photometry IC 15 via the DPU 13. The CPU 11 functions as a control unit that comprehensively controls the entire system of the camera body 10 and a correction function that corrects the aperture value, and also functions as a setting unit, a measurement unit, a release unit, a determination unit, and a determination unit. Have.

  An EEPROM 23, a motor driver 24, and an aperture control photo interrupter 29 are connected to the CPU 11. The EEPROM 23 stores various data relating to photographing, and the data is read out by the CPU 11 in a timely manner.

  A main motor 25 is connected to the motor driver 24, and the main motor 25 is controlled by the CPU 11 via the motor driver 24. The main motor 25 moves (charges) to the initial position against the spring force that travels the front curtain and rear curtain of the shutter, and moves (charges) the mirror 71 (see FIG. 1) to the initial position. A mechanism charge function that moves (charges) the aperture lever 61 for reducing the aperture to the initial position against the spring force. Each member is locked by a mechanical locking means (not shown) at the charge position.

  The aperture control photo interrupter 29 outputs an EE pulse in conjunction with the aperture operation of the aperture mechanism 60 that narrows the aperture device 110 of the interchangeable lens 100. The aperture mechanism 60 has an aperture lever 61 that controls the aperture by contacting the lens aperture interlocking lever 111 of the aperture device 110 of the interchangeable lens 100 (see FIGS. 2 and 3). In an initial state where the mirror 71 is down (see FIG. 1), the aperture lever 61 is mechanically locked at an open position that holds the aperture of the interchangeable lens 100 at the open position. When the mirror 71 is raised, the diaphragm lever 61 is released from mechanical locking, and slides in a direction that allows the diaphragm to be squeezed by the biasing force of the diaphragm spring and the pressing force of the interchangeable lens 100 by the lens diaphragm interlocking lever 111. Conventionally, the urging force for driving the lens aperture interlocking lever 111 of the interchangeable lens 100 in the squeezing direction is set stronger than the urging force for driving the aperture lever 61 of the camera body 10 in the squeezing direction. Slides with the lens aperture interlocking lever 111 in contact.

  Details of the narrowing mechanism will be described in more detail with reference to FIG. The aperture lever 61 is formed integrally with a slide plate 63 slidably guided by the camera body 10. The slide plate 63 is provided with 16 slits 63a and grooves (teeth) 63b with respect to the aperture value 1Av. Each time one of the slits 63a passes through the aperture control photointerrupter 29, the aperture control photointerrupter 29 is provided. To output one EE pulse. That is, 16 EE pulses are output per 1 Av. The CPU 11 counts every time this EE pulse is detected, and outputs a latch signal when the count value reaches the number of EE pulses obtained by the AE calculation, and turns on the transistor Tr that drives the aperture locking magnet EEMg. Then, power is supplied to the diaphragm locking magnet EEMg. The aperture stop magnet EEMg is formed of a permanent magnet and a coil. During normal times, the latch claw 65 is held in the release position where the latch pawl 65 is attracted by the magnetic force of the permanent magnet in the direction A in FIG. However, when energized, the magnetic force of the coil and the magnetic force of the permanent magnet cancel each other, and the latch claw 65 rotates in the direction B in FIG. The sliding operation of the aperture lever 61 is stopped. The stop of the aperture lever 61 stops the lens aperture interlocking lever 111 at that position, and the aperture device 110 is set to an aperture value corresponding to the stop position.

  The lens aperture interlocking lever 111 of the interchangeable lens 100 regulated by the aperture lever 61 moves in an arc shape along the inner circumference of the lens mount, as is well known, although details are not shown. Is configured to open and close. The lens diaphragm interlocking lever 111 is spring-biased in the direction of narrowing the diaphragm, and narrows the diaphragm to the minimum diaphragm in a free state. Thus, the lens aperture interlocking lever 111 contacts the aperture lever 61 when the interchangeable lens 100 is mounted on the camera body 10, and reaches the open position when the interchangeable lens 100 is relatively rotated to the normal mounting position. Forced to move. The open position here is not the open aperture position of the interchangeable lens 100 but a general-purpose open position that can open up to the maximum possible open aperture F value. Lens Aperture Interlocking Lever The lens aperture interlocking lever 111 is movable from the open aperture position to the open position, but is not involved in opening / closing of the aperture and is held in the open aperture state.

  Further, the CPU 11 is connected with a front curtain magnet 31, a rear curtain magnet 33, and a release magnet 35 as magnets in addition to the diaphragm locking magnet EEMg. The front curtain magnet 31 and the rear curtain magnet 33 are energized during the release process, and the front curtain and the rear curtain are respectively locked by electromagnetic force, and when the energization is cut off, the magnetic lock of the front curtain and the rear curtain is released. To control the travel. The release magnet 35 is energized after the front curtain magnet 31 and the rear curtain magnet 33 are energized to release the mechanical locking of the front curtain and the rear curtain.

  The CPU 11 is connected with a photometric switch SWS, a release switch SWR, a main switch SWM, a front curtain travel completion detection switch SWX, and a rear curtain travel completion detection switch SWY as switches. As is well known, the metering switch SWS and the release switch SWR are interlocked with the shutter button 39, and when the shutter button 39 is half-pressed, the metering switch SWS is turned on, and when the shutter button is fully pressed, the release switch SWR is turned on. The main switch SWM is a switch that is linked to the main switch lever 37. When the main switch lever 37 is turned on and turned on, the main switch SWM starts supplying power to the peripheral circuit via the DPU 13 and executes an operation corresponding to each switch operation. To do.

  Furthermore, the CPU 11 has an external LCD 41 and a viewfinder LCD 43 that function as display means for displaying information necessary for photographing. When the main switch SWM is turned off, the external LCD 41 and the viewfinder LCD 43 display nothing. When the main switch SWM is turned on, the number of shots, ISO sensitivity, etc. are displayed on the external LCD 41, and nothing is displayed on the in-finder LCD 43 until AE calculation is executed. After execution of the AE calculation, information useful for photographing such as the set appropriate shutter speed and the appropriate aperture value is displayed on the external LCD 41 and the in-finder LCD 43.

  The above is the main configuration of the control system of the camera body 10, but the camera body 10 also includes an AF device (AF sensor unit, AF motor) that performs automatic focus adjustment by detecting the focus state of a subject (not shown). In the case of a digital camera, an image sensor, an image signal processing circuit, an LCD for displaying an image, an image recording circuit for recording a captured image on a recording medium, etc. Comprises a film feeder.

  Next, an outline of the narrow-down control operation of the camera body 10 will be described. When the shutter button 39 is pressed halfway and the photometry switch SWS is turned on, the camera body 10 (CPU 11) starts photometry processing, obtains the subject brightness Bv from the brightness signal input from the photometry IC 15, and obtains the obtained subject brightness Bv and ISO sensitivity. AE calculation is performed based on Sv and the like, and an appropriate exposure value Ev, an appropriate shutter speed Tv, an aperture value Av, and an EE pulse number corresponding to the appropriate aperture value Av are obtained. When the shutter button 39 is fully pressed and the release switch SWR is turned on, the CPU 11 starts the release process. First, the CPU 11 energizes the front curtain magnet 31 and the rear curtain magnet 33 to lock the front curtain and the rear curtain by electromagnetic force, and energizes the release magnet 35 to release the mechanical locking of the front curtain and the rear curtain. .

  Next, the mirror 71 is moved up via the main motor 25, the mechanical locking of the aperture mechanism 60 is released, the aperture lever 61 is operated to reduce the aperture, and the EE pulse output from the aperture control photo interrupter 29 is checked. When the EE pulse is detected, count processing for adding 1 to the count value is executed. When the count value of the EE pulse reaches the number of EE pulses obtained by the AE calculation, the aperture stop magnet EEMg is energized, the aperture operation of the aperture lever 61 is stopped, and it waits until the mirror up is completed.

  When the mirror up is completed, the check of the EE pulse is stopped, and the running of the shutter curtain is controlled and exposed at the set appropriate shutter speed Tv.

  The above is a normal aperture control operation in a single-lens reflex camera. The normal aperture control is based on the premise that the movement amount of the aperture lever and the change in aperture value are in a linear relationship. However, the movement amount of the aperture lever 61 corresponding to the calculated aperture value and the actual aperture value change may become nonlinear due to mechanical errors of the aperture device 110 in the interchangeable lens 100. The embodiment of the present invention is characterized by reducing an error between the calculated aperture value and the actual aperture value even in such a non-linear case. The aperture value control apparatus and aperture value control method of the present invention applied to this single-lens reflex camera will be described below.

  FIG. 4 is a graph for explaining the aperture value correction effect by the aperture value control apparatus to which the first embodiment of the present invention is applied. 4A is a graph showing the error when the aperture value is not corrected, FIG. 4B is a graph showing the correction amount of the aperture value according to the first embodiment, and FIG. FIG. 7 is a graph showing a control amount error that is a difference between a set aperture value and an actual aperture value when the aperture value is corrected according to the first embodiment.

In the first embodiment, the correction data stored in the lens memory 103 in the interchangeable lens 100 is the Av value of the diaphragm that serves as a reference for correction, the number N of steps from the open position, and the unit correction amount K per 1 Ev. , Is set as Then, the CPU 11 sets the Av value of the stop used as a reference as Avs based on the number of steps N and the unit correction amount K which are correction data input from the lens memory 103,
(Avs + N-Av) × K
Calculated by The aperture value is corrected by the correction value Avs thus obtained. In this camera, the driving amount of the diaphragm lever 61, that is, the number of EE pulses is corrected.

  As is apparent from FIG. 4, the first embodiment is effective for error correction in which the control amount error changes linearly from the reference Av to the minimum aperture.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram for explaining the aperture value correction effect by the aperture value control apparatus according to the second embodiment of the present invention using the same graph as FIG. In FIG. 5, (A) is a graph showing the error when the aperture value is not corrected, (B) is a graph showing the aperture value correction amount according to the second embodiment, and (C) is a graph showing the second embodiment. FIG. 7 is a graph showing the aperture control error when the aperture value is corrected by the graph. In the second embodiment, the aperture value error changes from minus to plus in the range from the open position to the reference aperture value Av, and is suitable for replacement lesbians that change in the minus direction after exceeding the reference Av. .

In the second embodiment, the format of the correction data stored in the lens memory 103 in the interchangeable lens 100 is the Av value of the diaphragm that serves as a reference for correction, the number N of stages from the open position, and the reference value for correction from the open position. The unit correction amount KE per 1 Ev within the range up to the Av value of the aperture, and the unit correction amount KS per 1 Ev from the Av value of the aperture serving as the correction reference to the minimum aperture are set. Then, based on the number of steps N and the unit correction amounts KE and KS that are correction data input from the lens memory 103, the CPU 11 sets the aperture value of the reference aperture as the open aperture Avs value, and the CPU 11 sets the aperture control value. The correction amount to be corrected
From the open state to the range of the reference aperture Avs value,
(Avs + N-Av) x KS
Calculated by
From the standard aperture standard aperture Avs value to the minimum aperture,
(Avs + N-Av) × KE
Calculated by The driving amount of the aperture lever 61 is corrected based on the correction value thus obtained.

  As is apparent from FIG. 5, this embodiment is effective when the control error curve from the open position to the reference Av and the control error curve from the reference Av to the minimum aperture are discontinuous or inflected.

  As described above, when the aperture value when the aperture lever 61 of the camera body 10 is stopped is different from the aperture value of the aperture device of the interchangeable lens 100, the aperture value control device that can reduce these errors and the same 3 is an embodiment of a control algorithm. Next, if the aperture lever 61 cannot be stopped at the set aperture value even if the aperture stop magnet EEMg is energized at the set aperture value, the aperture lever 61 may be stopped at the set aperture value. Embodiments relating to a possible aperture value control apparatus and its control algorithm will be described.

The aperture device 110 is formed so that the lens aperture interlocking lever 111 accelerates from the aperture start (open position), maintains the speed when it reaches a predetermined speed, that is, moves at a constant speed, and decelerates when it approaches the maximum aperture value Av. Has been. The acceleration and the constant speed vary depending on the manufacturing error of the diaphragm device or the model. On the other hand, the time required from when the latch signal is output until the aperture stop magnet EEMg is energized and the latch claw 65 engages with the groove 63b is constant. The timing for outputting the latch signal is set based on the fact that the lens aperture interlocking lever 111 is accelerated at a predetermined acceleration and moves at a predetermined constant speed. Therefore, when the lens aperture interlocking lever 111 is accelerated at the design acceleration and moves at the design constant speed, the number of EE pulses corresponding to the calculated appropriate aperture Av is reached and a latch signal is output, and the latch claw 65 is inserted into the groove 63b. When engaged, the aperture lever 61 stops at a position where an appropriate aperture value Av is obtained.
However, when the acceleration and the constant speed of the lens aperture interlocking lever 111 are slower than the design value, the number of grooves 63b that pass while outputting the latch signal and the latch pawl 65 engages the groove 63b is larger than a predetermined number. The aperture value Av is set to be small and overexposure occurs. On the other hand, when the acceleration and constant speed of the lens aperture interlocking lever 111 are faster than the design value, the number of grooves 63b that pass while the latch claw 65 locks the groove 63b by outputting a latch signal is greater than a predetermined number. And the aperture value Av is set large, resulting in underexposure. Therefore, in the embodiment of the present invention, an aperture correction value for correcting the aperture value is set based on the relationship between the speed change of the aperture lever 61 and the aperture value.

  FIG. 6 is a graph for explaining the aperture value correction effect by the aperture control apparatus that provides the third embodiment of the present invention. 6A is a graph illustrating the relationship between the moving speed of the lens aperture interlocking lever 111 and the aperture value, and FIG. 6B is a graph illustrating the relationship between the aperture value correction amount and the aperture value. FIG. 8C is a graph illustrating the aperture value error when corrected according to the third embodiment.

  When the lens aperture interlocking lever 111 is released at the open position, it accelerates at a substantially constant acceleration from the open position to the aperture value Av4, moves at an approximately constant speed from the aperture value Av4 to the aperture value Av16, and starts from the aperture value Av16. Deceleration at a substantially constant acceleration. Therefore, in the embodiment of the present invention, the aperture value Av4 is the first reference value D1, the aperture value Av16 is the second reference value D2, and the acceleration interval from the open position to the first reference value D1, the first reference value Dividing into a constant speed section from D1 to the second reference value D2 and a deceleration section from the second reference value D2 to the minimum diaphragm (maximum diaphragm Av), correction data corresponding to the diaphragm value Av of each section is set. did. Here, Avo is the open aperture value of the interchangeable lens 100 (aperture device 110), Ks1 is the correction coefficient for the acceleration section from the open position to the first reference value D1, and Ks2 is the first reference value D1 to the second reference value. A correction coefficient for a constant speed section up to a value D2, Ks3 is a correction coefficient for a deceleration section from the second reference value D2 to the minimum aperture. Further, C1 is an acceleration interval correction constant, C2 is a constant speed interval correction constant, and C3 is a deceleration interval correction constant.

Next, the aperture value control process in the third embodiment will be described with reference to the flowchart shown in FIG. When entering the aperture value control process, the control EE pulse PNs is expressed by the following equation:
PNs = (Av−Avo) × 16
(Step S101).
Here, Av is an aperture value to be controlled, and Avo is an open aperture value of the interchangeable lens 100 (aperture device 110).

Next, it is checked whether or not the aperture value Av to be controlled is less than D1 (step S103). If it is less than D1 (step S103: YES), the corrected EE pulse PNc is expressed by the equation:
PNc = (Ks1 × Av + C1) × 16
(Step S105). Then, the control pulse number PN is obtained from the corrected EE pulse PNc and the calculated pulse number PNs (step S113), and this flowchart is exited.

If the aperture value Av to be controlled is not less than D1 (S103: NO), it is checked whether the aperture value Av to be controlled is greater than or equal to D1 and less than D2 (S107). When the aperture value Av to be controlled is not less than D1 and less than D2 (S107: YES), the corrected EE pulse PNc is expressed by
PNc = (Ks2 × Av + C2) × 16
(Step S109).
When the aperture value Av to be controlled is not greater than D1 and less than D2 (S107: NO), the corrected EE pulse PNc is expressed by the equation:
PNc = (Ks3 × Av + C3) × 16
(Step S109). Then, the control pulse number PN is obtained from the corrected EE pulse PNc and the calculated pulse number PNs (step S113), and this flowchart is exited.

  As described above, in the third embodiment, it is possible to correct an actual aperture value error that occurs when the moving speed of the lens aperture interlocking lever 111 is different from the design value. In particular, in a new interchangeable lens, even if the moving speed of the lens aperture interlocking lever 111 is set faster than before, aperture value correction data for correcting the error of the actual aperture value based on the speed difference is written in the lens memory. Thus, when the camera is mounted on a camera body that can use the correction data, it is possible to suppress the occurrence of an aperture value error. According to the third embodiment, the release time lag can be further shortened.

  Further, in the third embodiment, the correction data based on the mechanical error of the diaphragm device 110 of the interchangeable lens 100 is added to the correction coefficients and the correction constants as shown in the first and second embodiments. Also good.

  The present invention is applicable not only to a single-lens reflex camera as long as it is an interchangeable lens camera, and can be applied to any silver film camera or digital camera.

It is the perspective view which looked at the external appearance of embodiment of the camera body 10 of the interchangeable lens camera which mounts the aperture value control apparatus of this invention from the front. It is a figure which shows the embodiment of the control system main structure regarding aperture control mounted in the camera body by a block. It is a figure which shows the principal part of the aperture mechanism with an aperture lever mounted in the camera body. FIG. 5 is a graph for explaining the aperture value correction effect by the aperture value control apparatus according to the first embodiment of the present invention, in which FIG. (A) is a graph showing an error when the aperture value is not corrected; ) Is a graph showing the correction amount of the aperture value according to the first embodiment, and (C) is the difference between the set aperture value and the actual aperture value when the aperture value is corrected according to the first embodiment. It is a figure which shows a control amount error with a graph. FIG. 5A is a graph for explaining the aperture value correction effect by the aperture value control apparatus according to the second embodiment of the present invention in the same graph as FIG. 4, and FIG. 5A is a graph showing an error when the aperture value is not corrected. FIGS. 4A and 4B are graphs showing the correction amount of the aperture value according to the second embodiment. FIG. 4C is a graph showing the aperture control error when the aperture value is corrected according to the second embodiment. . FIG. 7A is a graph for explaining an aperture value correction effect by an aperture value control apparatus according to a third embodiment of the present invention, and FIG. 5A is a graph showing an error when an aperture value is not corrected, ) Is a graph illustrating the relationship between the aperture value correction amount and the aperture value, and C) is a graph illustrating the aperture value error when corrected according to the third embodiment. It is a figure which shows the operation | movement of the aperture_diaphragm | restriction control apparatus which is the said 3rd Embodiment with a flowchart. It is a figure explaining the error by the conventional aperture control, (A) is the error between the aperture value controlled by the aperture lever and the actual aperture value when the movement amount of the aperture lever and the aperture value change are nonlinear. (B) is a graph showing the relationship between the correction amount corrected by the conventional exposure correction data and the aperture value, and (C) is the design value of the moving speed of the aperture lever in the conventional exposure correction device. It is a figure which shows the difference | error of the setting aperture value and actual aperture value which arise when it deviates from.

Explanation of symbols

10 Camera body 11 CPU
29 aperture control photo interrupter 60 aperture mechanism 61 aperture lever 63 slide plate 63a slit 63b groove 65 latch claw 100 interchangeable lens 101 lens CPU
103 Lens memory 110 Aperture device 111 Lens aperture interlocking lever PN Number of control pulses (aperture control value)

Claims (12)

A lens-replaceable camera with a detachable lens,
An aperture value control means for controlling the aperture device of the interchangeable lens that opens and closes the aperture in conjunction with the movement of the aperture lever, by controlling the amount of movement of the aperture lever;
Storage means for storing correction data for correcting an aperture error caused by mechanical elements of the interchangeable lens,
The correction data includes the movement amount of the aperture lever so that the aperture value set in the camera matches the actual aperture value of the aperture device controlled by the aperture lever of the aperture value control means based on the aperture value. A lens-interchangeable camera provided with an aperture value control device, characterized in that it is correction data for correcting an aperture control value for controlling the aperture. The interchangeable-lens camera provided with the aperture value control device according to claim 1, wherein the aperture lever includes an aperture value control device that moves in an aperture direction from an open position, and the movement amount is controlled as a plurality of stages. Interchangeable lens camera. In the interchangeable lens camera provided with the aperture value control device according to claim 2, the correction data stored in the storage means is:
Lens interchangeable type equipped with an aperture value control device that is set as the number of steps N required for the aperture lever to move from the open position to the Avs value of the reference aperture that is the reference for correction, and the unit correction amount K per 1 Ev camera. In the interchangeable lens camera provided with the aperture value control device according to claim 2, the correction data stored in the storage means is:
The number of steps N required for the diaphragm lever to move from the open position to the Avs value of the reference diaphragm that serves as a correction reference,
Within the aperture value range from the open position to the Avs value of the reference aperture that is the reference for correction, the unit correction amount KE per 1 Ev, and the aperture from the Avs value of the reference aperture that is the reference for correction to the Av value of the minimum aperture An interchangeable-lens camera provided with an aperture value control device set as a unit correction amount KS per 1 Ev within the value range. 3. The interchangeable lens camera provided with the aperture value control device according to claim 2, wherein the correction data stored in the storage means is an open aperture value Avo, and a first reference value at which the aperture lever accelerates from the open position. The correction coefficient for the acceleration section up to D1 is Ks1, the correction constant is C1, the correction coefficient for the constant speed section from the first reference value D1 to the second reference value D2 where the aperture lever moves at a constant speed is Ks2, and the correction constant. Is a lens-interchangeable camera in which C2 is set as the correction coefficient for the deceleration zone from the second reference value D2 at which the aperture lever decelerates to the minimum aperture, and the correction constant is C3. In the interchangeable lens camera provided with the aperture value control device according to claim 3, the aperture value control means expresses a correction amount for correcting the aperture control value,
(Avs + N-Av) × K
Interchangeable lens camera equipped with an aperture value control device for calculating by the above. 5. The interchangeable lens camera provided with the aperture value control device according to claim 4, wherein the aperture value control means sets a correction amount for correcting the aperture control value.
In the aperture value range from the open state to the reference aperture Avs value,
(Avs + N-Av) x KS
Is calculated by
From the standard aperture Avs value to the minimum aperture value,
(Avs + N-Av) × KE
Interchangeable lens camera equipped with an aperture value control device for calculating by the above. 6. The interchangeable-lens camera provided with the aperture value control device according to claim 5, wherein an Av value of the reference reference aperture is an open aperture Avs value, and the aperture value control means sets the correction amount,
If the aperture value Av to be controlled is less than D1, the formula:
(Ks1 × Av + C1)
If the aperture value Av to be controlled is greater than or equal to D1 and less than D2,
(Ks2 × Av + C2)
When the aperture value Av to be controlled is equal to or greater than D2, the equation (Ks3 × Av + C3)
Interchangeable lens camera equipped with an aperture value control device for calculating by the above. An interchangeable lens for an interchangeable lens camera,
An aperture device whose aperture is controlled by the amount of movement of the aperture lever of the camera;
Storage means for storing correction data for correcting an aperture error caused by mechanical elements of the interchangeable lens,
The correction data controls the movement amount of the aperture lever so that the aperture value set in the camera matches the actual aperture value of the aperture device controlled by the aperture lever of the camera based on the aperture value. An interchangeable lens, which is correction data for correcting an aperture control value. The interchangeable lens according to claim 9, wherein the correction data stored in the storage means is
An interchangeable lens provided with an aperture value control device set by the number of steps N required for the aperture lever to move from the open position to the Av value of the reference aperture that is a reference for correction, and the unit correction amount K per 1 Ev. The interchangeable lens according to claim 9, wherein the correction data stored in the storage means is
The number of steps N required for the diaphragm lever to move from the open position to the Av value of the diaphragm serving as a correction reference,
Within the aperture value range from the open position to the Av value of the reference aperture that is the reference for correction, the unit correction amount KE per 1 Ev, and the aperture from the Av value of the reference aperture that is the reference of correction to the Av value of the minimum aperture An interchangeable lens having an aperture value control device set by a unit correction amount KS per 1 Ev within a value range. The interchangeable lens according to claim 9, wherein the correction data stored in the storage means is
The open aperture value is Avo, the correction coefficient of the acceleration section from the open position to the first reference value D1 at which the aperture lever accelerates is Ks1, the correction constant is C1, and the first reference value D1 at which the aperture lever moves at a constant speed. The correction coefficient for the constant speed section from K2 to the second reference value D2 is Ks2, the correction constant is C2, the correction coefficient for the deceleration section from the second reference value D2 to which the aperture lever decelerates to the minimum diaphragm is Ks3, and the correction constant is An interchangeable lens provided with an aperture value control device set as C3.

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