JP4701014B2 - Camera with focus adjustment device - Google Patents

Description

  The present invention relates to a system single-lens reflex camera capable of exchanging lenses, and more particularly to a camera having a focus adjustment device.

A focus adjustment device for a system single-lens reflex camera capable of exchanging lenses is disclosed in, for example, Japanese Patent Application Laid-Open No. H10-228707.
Japanese Patent Laid-Open No. 9-211649

  The focus adjustment device of a system single-lens reflex camera disclosed in Patent Document 1 and the like capable of exchanging lenses is capable of macro shooting for shooting an object at a short distance by performing autofocus (hereinafter abbreviated as AF). is there. Among macro photography, there is what is called 1x macro photography, which shoots a subject image at a full size.

It is known that the following phenomenon occurs in the case of the same magnification macro photography.
For example, when the focus lens is extended from the in-focus state, the defocus amount usually changes in the negative (front pin) direction for the same subject, but the defocus amount is positive ( Changes to the rear pin) direction.

  In normal magnification macro photography in which such a phenomenon occurs, there are the following problems when performing normal AF operation.

FIG. 12A shows, as an example, the relationship between the focus lens extension amount and the defocus amount of the photographing lens near the equal magnification macro region. FIG. 12B shows the relationship between the focus lens feed amount and the photographing magnification.
As shown in the figure, when the focus lens is extended from the in-focus state A where the defocus amount is 0, the defocus amount changes in the negative direction.
However, the defocus amount shows a peak at point C, and thereafter, the change of the defocus amount becomes a positive direction, and the point B is again focused at a photographing magnification (equal magnification) different from the point A.
Since such a phenomenon occurs, the AF operation becomes impossible in the section from the point C to the point B, which is very unusable.

  Also, when the AF operation is performed when the focus lens is at point B, when the viewfinder is observed, the focus is first out of focus (point B) and then passes through point C. Thus, the AF operation with a sense of incongruity is performed in which the point A is reached and the image is focused at a magnification different from the first.

  A device such as a camera that improves the poor usability as described above has not been proposed yet.

  The present invention has been made in view of the above points, and in a system single-lens reflex camera capable of exchanging lenses, focus adjustment capable of improving the usability of focus adjustment at the time of macro photography for photographing a short-distance subject. An object is to provide a camera having an apparatus.

A first aspect of the camera having the focus adjustment device of the present invention is as follows.
A photographic lens that includes a focus lens and forms an optical image of the subject;
A main body to which the above photographing lens can be attached;
An intermediate ring that can be mounted between the photographic lens and the main body;
Comprising
The above photographic lens
Storage means for storing information relating to a region in which movement of the focus lens is prohibited , including the position of the focus lens corresponding to the same magnification macro corresponding to the type of the intermediate ring when the intermediate ring is mounted ;
The movement of the focus lens is controlled based on an instruction from the main body, and the information based on the information on the region where the movement of the focus lens is prohibited according to the type of the attached intermediate ring output from the storage means. Control means for controlling the movement of the focus lens into a region where the movement of the focus lens including the position of the focus lens corresponding to the same magnification macro is prohibited ;
It is characterized by having.
The second aspect of the camera having the focus adjustment device of the present invention is as follows.
A photographic lens that includes a focus lens and forms an optical image of the subject;
A main body to which the above photographing lens can be attached;
An intermediate ring that can be mounted between the photographic lens and the main body;
Comprising
The intermediate ring stores information relating to a region in which movement of the focus lens is prohibited, including the position of the focus lens corresponding to the same magnification macro corresponding to the type of the photographing lens when the photographing lens is mounted. Have
The photographing lens controls the movement of the focus lens based on an instruction from the main body, and prohibits the movement of the focus lens according to the type of the photographing lens from the storage unit of the attached intermediate ring. Information on the area is acquired, and control is performed so as to prohibit the movement of the focus lens into an area where the movement of the focus lens including the position of the focus lens corresponding to the equal magnification macro is prohibited based on the information. It has the control means to do.
The main body has display means for displaying the result of the focus adjustment operation,
The display means may display a warning when the photographing lens performs an operation of prohibiting the movement of the focus lens into an area where the movement of the focus lens is prohibited.

According to the present invention , AF in a lens position area where AF cannot be performed is prohibited in a system single lens reflex camera capable of exchanging lenses, or an AF disabled state is notified to a photographer. It is possible to provide a camera having a focus adjustment device capable of improving the usability of focus adjustment during double macro photography.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing a system configuration of a digital camera (hereinafter simply referred to as a camera) 10 as a camera having a focus adjustment apparatus according to a first embodiment of the present invention. FIG. 10 is a perspective view schematically showing an internal configuration of a camera body by cutting a part of the camera body in order to show the configuration of FIG.

  The camera 10 includes a camera body 12 and a lens barrel 14 that are interchangeable photographing lenses. The camera body 12 and the lens barrel 14 are configured to be detachable from each other. It will be.

  The lens barrel 14 is configured by holding therein a photographing optical system 16 including a plurality of lenses including a focus lens, a lens driving mechanism 18 and the like. For example, the photographing optical system 16 transmits a light beam from a subject so that an image of the subject formed by the subject light beam is formed at a predetermined position (on the photoelectric conversion surface of the image sensor 20). A plurality of optical lenses are used. The lens barrel 14 is disposed so as to protrude toward the front surface of the camera body 12.

  The camera body 12 includes various components and the like, and is an imaging optical device that is a connecting member for detachably mounting a lens barrel 14 that holds the imaging optical system 16. This is a so-called single-lens reflex camera having the system mounting portion 22 provided on the front surface thereof. That is, an exposure opening having a predetermined aperture capable of guiding the subject light flux into the camera body 12 is formed at a substantially central portion on the front side of the camera body 12. A photographing optical system mounting portion 22 is formed.

  On the outer surface side of the camera body 12, the above-described photographic optical system mounting portion 22 is disposed on the front surface thereof, and for operating the camera body 12 at a predetermined position such as an upper surface portion or a back surface portion. Various operation members, for example, a release button 24 for generating an instruction signal for starting a photographing operation and the like are provided.

  Inside the camera body 12 are various components such as a finder device 26 that constitutes a so-called observation optical system, and a shutter mechanism that controls the irradiation time of the subject luminous flux on the photoelectric conversion surface of the image sensor 20. The shutter unit 28 provided, the image sensor 20 that obtains an image signal corresponding to the subject image, and a predetermined position on the front side of the photoelectric conversion surface of the image sensor 20, such as dust on the photoelectric conversion surface A plurality of circuit boards including an image pickup unit 32 including a dustproof filter (also referred to as dustproof glass) 30 which is a dustproof member for preventing adhesion, and a main circuit board 34 on which various electric members constituting the electric circuit are mounted. (Only the main circuit board 34 is shown in FIG. 2) and the like are arranged at predetermined positions.

  The finder device 26 is configured to receive a light beam emitted from the reflecting mirror 26A and a reflecting mirror 26A configured to bend the optical axis of the subject light beam that has passed through the photographing optical system 16 and to guide the light beam to the observation optical system side. A pentaprism 26B that forms an erect image, an eyepiece lens 26C that forms an image in an optimum form for magnifying and observing an image formed by the pentaprism 26B, and the like.

  Here, the reflecting mirror 26A is configured to be movable between a position retracted from the optical axis of the photographic optical system 16 and a predetermined position on the optical axis, and in a normal state, the optical axis of the photographic optical system 16 is configured. Above, the optical axis is arranged with a predetermined angle, for example, an angle of 45 degrees. As a result, when the camera 10 is in the normal state, the subject luminous flux that has passed through the photographing optical system 16 is bent by the reflecting mirror 26A, and the pentaprism 26B disposed above the reflecting mirror 26A. Reflected to the side of the. On the other hand, while the camera 10 is performing a photographing operation, the reflecting mirror 26A moves to a predetermined position that is retracted from the optical axis of the photographing optical system 16, whereby the subject light flux is captured by the image sensor. Guided to the side.

  For the shutter unit 28, for example, a focal plane type shutter mechanism and its driving circuit, which are generally used in a conventional camera or the like, are applied.

  The lens barrel 14 is controlled by a lens control microcomputer (hereinafter referred to as Lμcom) 36. The camera body 12 is controlled by a body control microcomputer (hereinafter referred to as Bμcom) 38. Note that these Lμcom 36 and Bμcom 38 are electrically connected via the communication connector 40 so as to be communicable at the time of combination. In this case, the Lμcom 36 operates as a camera system in cooperation with the Bμcom 38 in a dependent manner.

Further, as described above, the photographing optical system 16 and the lens driving mechanism 18 are provided in the lens barrel 14, and the photographing optical system 16 is driven by a DC motor (not shown) in the lens driving mechanism 18. Driven. Furthermore, a stop 42 is provided in the lens barrel 14, and this stop 42 is driven by a stepping motor (not shown) in the stop drive mechanism 44.
The Lμcom 36 controls each of these motors in accordance with a command from the Bμcom 38.

  In addition to the above-described reflecting mirror 26A, pentaprism 26B, and eyepiece lens 26C, the camera body 12 receives a sub-mirror 46, which is a single-lens reflex system component, and a reflected light beam from the sub-mirror 46. And an AF sensor unit 48 for automatic ranging.

  Further, an AF sensor driving circuit 50 for driving and controlling the AF sensor unit 48, a mirror driving mechanism 52 for driving and controlling the reflecting mirror 26A, and a spring force for driving the front curtain and the rear curtain of the shutter section 28 are provided. A shutter charge mechanism 54 for charging, a shutter control circuit 56 for controlling the movement of the front curtain and the rear curtain, and a photometric circuit 58 for performing photometric processing based on the light flux from the pentaprism 26B are provided.

  On the optical axis, the imaging element 20 for photoelectrically converting the subject image that has passed through the photographing optical system 16 is provided as a photoelectric conversion element. In this case, the image sensor 20 is protected by the dust filter 30 made of a transparent glass member as an optical element disposed between the image sensor 20 and the photographing optical system 16.

  In order to vibrate the dust filter 30 at a predetermined frequency, the piezoelectric element 60 is attached to the peripheral edge of the dust filter 30. The piezoelectric element 60 has two electrodes, and the piezoelectric element 60 is configured to vibrate the dust filter 30 by the dust filter driving circuit 62 and remove dust adhering to the glass surface. ing.

  In order to measure the temperature around the image sensor 20, a temperature measurement circuit 64 is provided in the vicinity of the dust filter 30.

  The camera 10 also includes an interface circuit 66 connected to the image sensor 20, a liquid crystal monitor 68, an SDRAM 70 provided as a storage area, a flash ROM 72, a recording medium 74, and the like, and an image processing controller that performs image processing. 76, and an electronic image display function as well as an electronic recording display function can be provided.

  As the other storage area, a non-volatile memory 78 made of, for example, an EEPROM, which stores predetermined control parameters necessary for camera control, is provided so as to be accessible from the Bμcom 38.

  Further, the Bμcom 38 is provided with an operation display LCD 80 for notifying the user of the operation state of the camera by display output, and a camera operation switch (SW) 82. The camera operation SW 82 is a switch group including operation buttons necessary for operating the camera, such as a release SW, a mode change SW, a menu setting SW, and a power SW.

  Further, the camera 10 is provided with a battery 84 as a power source and a power circuit 86 that converts the voltage of the power source into a voltage required by each circuit unit constituting the camera 10 and supplies the converted voltage.

Next, the operation of the camera system configured as described above will be described.
Each part of this camera system operates as follows.

  First, the image processing controller 76 takes in image data from the image sensor 20 by controlling the interface circuit 66 in accordance with a command of Bμcom 38. This image data is converted into a video signal by the image processing controller 76 and output and displayed on the liquid crystal monitor 68. The user can check the captured image from the display image on the liquid crystal monitor 68.

  The SDRAM 70 is a memory for temporarily storing image data, and is used as a work area when image data is converted. The image data is set to be stored in the recording medium 74 after being converted into JPEG data.

  The image sensor 20 is protected by the dustproof filter 30 made of a transparent glass member as described above. A piezoelectric element 60 for oscillating the glass surface is disposed at the peripheral edge of the dust filter 30, and the piezoelectric element 60 is driven by a dust filter driving circuit 62. It is more preferable for dust prevention that the image pickup element 20 and the piezoelectric element 60 are integrally housed in a case having the dustproof filter 30 as one surface and surrounded by a frame as shown by a broken line.

  By the way, the temperature usually affects the elastic coefficient of a glass material and is one of the factors that change its natural frequency. Therefore, the temperature is measured during operation and the change of the natural frequency is taken into consideration. There must be. It is preferable to measure the temperature change of the dustproof filter 30 provided in order to protect the front surface of the image sensor 20 where the temperature rises rapidly during operation, and to predict the natural frequency at that time. Therefore, in the camera 10, a sensor (not shown) connected to the temperature measurement circuit 64 is provided to measure the ambient temperature of the image sensor 20. The temperature measurement point of the sensor is preferably set in the vicinity of the vibration surface of the dust filter 30.

  The mirror driving mechanism 52 is a mechanism for driving the reflecting mirror 26A to the UP position and the DOWN position. When the reflecting mirror 26A is at the DOWN position, the light beam from the photographing optical system 16 is pentagonally connected to the AF sensor unit 48 side. The light is divided and guided to the prism 26B side.

  The output from the AF sensor in the AF sensor unit 48 is transmitted to the Bμcom 38 via the AF sensor driving circuit 50 and a known distance measurement process is performed.

  The eyepiece 26C adjacent to the pentaprism 26B allows the user to see the subject, while part of the light beam that has passed through the pentaprism 26B is guided to a photosensor (not shown) in the photometry circuit 58, where it is detected. A well-known photometric process is performed based on the light quantity.

  FIG. 3 is a flowchart of the main flow executed by the Bμcom 38 of the camera 10. That is, when the camera 10 is turned on, the main flow is started by the Bμcom 38.

  First, the entire system is initialized when the camera 10 is started (step S10).

  Thereafter, the state of the camera operation SW 82 is detected (step S12). Here, it is determined whether or not a state change of a mode change SW (not shown), which is one of the camera operation SWs 82, has been detected in the above step S12 (step S14). The operation mode of the camera is changed in conjunction with the SW (step S16). Then, information corresponding to the changed camera operation mode is displayed on the operation display LCD 80 (step S18), and the process returns to step S12.

  For example, when the AF / MF switching SW (not shown) is operated to switch from the AF mode to the MF (manual focus) mode, an MF operation is performed in which the photographer manually operates the focus ring of the lens barrel 14 to perform focusing. It becomes possible. Further, the display on the operation display LCD 80 is switched from AF to MF.

  On the other hand, if it is determined in step S14 that the state change of the mode change SW has not been detected, it is further determined whether or not the 1st release SW (not shown) which is one of the camera operation SWs 82 is turned on. (Step S20). That is, the release button 24 is a two-stage push button in which the 1st release SW is turned on in response to the first-stage depression, and the 2nd release SW (not shown) is turned on in the second-stage depression. ing. Therefore, here, it is determined whether or not the first-stage pressing operation of the release button 24 has been performed. If the first release SW is not turned on, the process returns to step S12.

  If it is detected that the 1st release SW is turned on, the subject brightness is measured by the photometry circuit 58 to determine the presence or absence of strobe light emission and to calculate the Tv value and the Av value (step S22). Then, the AF sensor unit 48 is controlled to detect a focus shift amount, and based on this focus shift amount, a subroutine “AF” for performing focus drive control by the lens drive mechanism 18 of the lens barrel 14 is executed (step S24). . Details of this subroutine “AF” will be described later.

  After execution of this subroutine “AF”, it is determined whether or not a 2nd release SW which is one of the camera operation SWs 82 has been operated (step S26). If the 2nd release SW is not turned on, the process returns to step S12.

  On the other hand, if the 2nd release SW is turned on, the diaphragm 42 is controlled by the diaphragm driving mechanism 44 in the lens barrel 14 (step S28). Then, mirror-up control for driving the quick return mirror (reflecting mirror 26A) to the photographing position by the mirror driving mechanism 52 is performed (step S30), and control for opening the shutter by running the front curtain of the shutter unit 28 is performed. (Step S32), the imaging operation (charge accumulation operation) of the image sensor 20 is performed (step S34).

  Thereafter, control is performed to move the rear curtain of the shutter unit 28 and close the shutter (step S36), mirror down control for driving the quick return mirror (reflecting mirror 26A) to the photographing preparation position by the mirror driving mechanism 52, and shutter charge. Shutter charge control is performed by the mechanism 54 (step S38), and control for opening the aperture 42 of the lens barrel 14 is further performed (step S40).

Then, the image processing controller 76 performs a recording operation for the acquired image data (step S42).
The operation of the main flow is completed as described above, and the process returns to step S12 to repeat the same operation.

  FIG. 4 is a flowchart showing details of the subroutine “AF” executed in step S24.

  In this subroutine “AF”, first, a focus detection operation for controlling the AF sensor unit 48 to detect the defocus amount of the photographing optical system 16 in the lens barrel 14 is performed (step S50).

  Then, it is determined whether or not the focus detection result is undetectable (step S52). If the focus detection result is undetectable, display in the finder or other display is performed (step S54). To finish.

  On the other hand, if the focus detection result is detectable, it is determined whether or not the focus detection result is in-focus within a predetermined defocus amount range (step S56).

  Here, in the case of out-of-focus, it is determined whether or not the focus lens position is near the equal magnification macro region (step S58). This is performed by reading the focus lens position from an encoder (not shown) included in the lens driving mechanism 18 of the lens barrel 14 and determining whether or not it is located in the vicinity of the equal magnification macro region.

  If the focus lens position is not in the vicinity of the equal-magnification macro area, focus driving of the photographic optical system 16 is executed based on the defocus amount obtained by focus detection in step S50 (step S60). Then, the process returns to step S50.

  On the other hand, if the focus lens position is near the equal magnification macro region, it is determined whether or not an inflection point (point C in FIG. 12) has already been detected (step S62). If the inflection point has not been detected yet, a subroutine “inflection point detection”, which will be described in detail later, is executed to obtain the inflection point (step S64). Then, the process returns to step S50.

  If an inflection point has already been detected, compare the detected inflection point with the current focus lens position, and check whether the current focus lens position is closer to the inflection point position. It is determined whether or not (step S66). Here, if it is not the short distance side, the process proceeds to step S60, the focus driving of the photographing optical system 16 is executed, and then the process returns to step S50.

  On the other hand, when the current focus lens position is located closer to the inflection point position, the AF disabled display corresponding to the same-magnification macro area is performed by display in the finder or other display (step S68), the subroutine “AF” is terminated. This is a display indicating that AF cannot be performed in the same-magnification macro area, and a display different from the undetectable display in step S54, for example, a blinking display in a different cycle of the LED display in the finder is performed. This display has a meaning of prompting the photographer to perform focusing in MF because AF is impossible.

  The above process is repeated, and if it is determined that the in-focus state is obtained in step S56, in-focus display or other in-focus display is performed (step S70), and this subroutine "AF" is terminated.

  FIG. 5 is a flowchart showing details of the subroutine “inflection point detection” executed in step S64.

  In this subroutine “inflection point detection”, first, an operation of extending the focus lens of the photographing optical system 16 by a predetermined amount is performed (step S80). Then, a focus detection operation for detecting the defocus amount of the photographing optical system 16 by controlling the AF sensor unit 48 is performed to obtain the defocus amount (step S82).

  Here, it is determined whether or not the defocus amount change direction is negative as compared with the defocus amount at the previous focus lens position (step S84).

  If the change direction is negative, the number of executions of the focus lens predetermined amount feeding operation in step S80 and the focus detection operation in step S82 is counted, and it is determined whether or not the predetermined number has been reached (step S86). If the predetermined number of times has not been reached, the process returns to step S80, and the focus lens predetermined amount feeding operation (step S80) and the focus detection operation (step S82) are repeatedly executed. On the other hand, if the predetermined number of times has been reached, a flag indicating no inflection point is set in a memory (not shown) in the Bμcom 38 or SDRAM 70 (step S88), and this subroutine “inflection point detection” is terminated.

  If it is determined in step S84 that the defocus amount change direction is not negative, the current focus lens position, which is the inflection point (point C in FIG. 12), is stored in the memory (not shown) or SDRAM 70 in the Bμcom 38. (Step S90).

  Thereafter, an operation of extending the focus lens of the photographing optical system 16 by a predetermined amount is performed (step S92), a focus detection operation is performed, and a defocus amount is obtained (step S94). Then, it is determined whether or not the defocus amount change direction is positive as compared with the defocus amount at the previous lens position (step S96).

  If the change direction is not positive, it is determined that there is a detection error, and this subroutine “inflection point detection” process is executed again. Therefore, after driving to return the focus lens position to the initial position that is the lens position before executing this subroutine (step S98), the process returns to step S80.

  On the other hand, if it is determined that the defocus amount change direction is positive, it is further determined whether or not the focus lens has reached the closest position (step S100). If the closest position has not yet been reached, the process returns to step S92, and the focus lens extension operation (step S92) and the focus detection operation (step S94) are repeated.

  If it is determined that the focus lens has reached the closest position, a drive for returning the focus lens position to the initial position which is the lens position before executing this subroutine is performed (step S102). The “inflection point detection” process is terminated.

  As described above, in the region where the AF operation cannot be normally performed in the vicinity of the equal-magnification macro region (from point C to point B in FIG. 12), the focus lens position at the inflection point C is detected and stored. Since the prohibited area is set so as not to extend the focus lens beyond the stored point C, the photographer does not feel uncomfortable.

  In addition, when the focus lens is located near the inflection point, the photographer is notified by a display in the finder, etc., so that it is possible to focus by switching to the MF mode when focusing is desired at the B point. good.

[Second Embodiment]
It is called an intermediate ring (or close-up ring) and is used by being mounted between the camera body 12 and the lens barrel 14 including the photographing optical system 16 and is further closer than when only the photographing optical system 16 is attached. In general, accessories having an effect of enabling photographing are known.

  By mounting such an intermediate ring between the camera body 12 and the photographic optical system 16 (lens barrel 14), the back focus is extended and the shootable distance range of the photographic optical system 16 is reduced. Since it can be shifted to the side, it is possible to shoot in the macro area.

  Furthermore, if the type of the photographing optical system 16 is a macro system, it is possible to photograph in the same magnification macro region.

  The second embodiment is applied when the above-described intermediate ring is used. Since the specific system configuration of the camera 10 having the focus adjustment apparatus according to the present embodiment is the same as that of FIG. 1 described in the first embodiment, the description thereof is omitted.

  FIG. 6 is a flowchart of the main flow executed by the Bμcom 38 of the camera 10. That is, when the camera 10 is turned on, the main flow is started by the Bμcom 38.

  First, the entire system is initialized when the camera 10 is started (step S10).

  Thereafter, in the present embodiment, mounting detection of the lens barrel 14 (including the intermediate ring) having the photographing optical system 16 is executed (step S110). Then, it is determined whether or not the lens barrel 14 (including the intermediate ring) is attached (step S112).

  If it is determined that the lens is attached, a lens flag provided in a memory (not shown) in the Bμcom 38 or the SDRAM 70 is set (step S114). Then, it communicates with the lens barrel 14 and acquires necessary data. Thereafter, it is determined whether or not an intermediate ring is attached (step S116). If it is attached, an intermediate ring flag provided in a memory (not shown) in the Bμcom 38 or SDRAM 70 is set (step S118). . Then, communication with the intermediate ring is performed, and data stored in a memory element (not shown) such as an EEPROM in the intermediate ring is read (step S120). Thereafter, the process proceeds to step S12 as described in the first embodiment.

  If it is determined in step S116 that the intermediate ring is not attached, the intermediate ring flag is cleared (step S122). Thereafter, the process proceeds to step S12 as described in the first embodiment.

  On the other hand, if it is determined in step S112 that the lens barrel 14 (including the intermediate ring) is not attached, whether or not the lens barrel 14 (including the intermediate ring) including the photographing optical system 16 has been removed. (Step S124), and if not removed, the process proceeds to step S12 as described in the first embodiment. If the lens barrel 14 is removed, the lens barrel 14 is not attached. Therefore, after the lens flag is cleared (step S126), the process proceeds to step S12 as described in the first embodiment.

  The subsequent processing in steps S12 to S42 is executed in step S24, and the return destination after the processing in steps S18 and S42 is step S110 when NO is determined in steps S20 and S26. The subroutine “AF” is the same as that of the first embodiment except that the contents of the subroutine “AF” are different, and the description thereof is omitted.

  FIG. 7 is a flowchart showing details of the subroutine “AF” executed in step S24 in the present embodiment. Only the parts different from the first embodiment will be described, and the description of the other parts will be omitted.

  That is, in the subroutine “AF” in the present embodiment, when the in-focus state is determined in step S56, the intermediate ring flag set in the main flow of FIG. 6 is referred to (step S130), which is cleared. If so, the process proceeds to step S58.

  On the other hand, if the intermediate ring flag is set, the shooting magnification is calculated (step S132), and the process proceeds to step S58. This magnification calculation is calculated by reading the length of the ring according to the type of the intermediate ring and the focus lens position from the encoder included in the lens driving mechanism 18 of the lens barrel 14.

  In step S58, it is determined whether or not it is near the same magnification macro area (the photographing magnification is near 1) based on the photographing magnification.

  As described above, even when the intermediate ring is used, the same effect as that of the first embodiment can be obtained.

[Third Embodiment]
The camera 10 having the focus adjusting apparatus according to the third embodiment of the present invention uses an intermediate ring as in the second embodiment, and FIG. 8A shows a block diagram.

  That is, in the camera 10, the lens barrel 14 includes a memory element 88 (e.g., an EEPROM) as a storage means in addition to an Lμcom 36 that functions as a control means and a lens drive mechanism 18 that functions as a focus lens moving means. Yes.

  When the intermediate ring 90 and the lens barrel 14 are attached to the camera body 12, the Bμcom 38 in the camera body 12 detects that it is attached by communicating with the intermediate ring 90. The detection result of Bμcom 38 is output to Lμcom 36 in the lens barrel 14. The Lμcom 36 acquires information on the inflection point position stored in advance in the memory element 88. The inflection point position data is electrically written in the memory element 88 when the lens barrel 14 (exchangeable photographing lens) is manufactured. As a measurement method at the time of manufacture, the inflection point may be obtained by the method shown in FIG. 7 of the second embodiment and written into the memory element 88.

  The Lμcom 36 controls the lens driving mechanism 18 by comparing the position information of the focus lens of the photographing optical system 16 with the inflection point position acquired from the memory element 88. That is, in the vicinity of the same magnification macro, the operation of moving the focus lens closer to the closest side than the inflection point position by the AF operation is prohibited.

  Other configurations of the camera body 12 and the lens barrel 14 are the same as those in the first embodiment (FIG. 1). The main flow is the same as that of the second embodiment (FIG. 6). Therefore, those descriptions are omitted.

  FIG. 9 is a flowchart showing details of the subroutine “AF” executed by the Bμcom 38 in step S24 in the present embodiment.

  In other words, in the present embodiment, the Bμcom 38 first performs a focus detection operation for controlling the AF sensor unit 48 to detect the defocus amount of the photographing optical system 16 in the lens barrel 14 (step S50). Then, it is determined whether or not the focus detection result is undetectable (step S52). If the focus detection result is undetectable, display in the viewfinder or other display is performed (step S54), and this subroutine "AF" Exit.

  On the other hand, if the focus detection result is detectable, it is determined whether or not the focus detection result is in-focus within a predetermined defocus amount range (step S56). If it is determined that the subject is in focus, in-focus display or other in-focus display is performed (step S70), and this subroutine "AF" is terminated.

  On the other hand, if the in-focus state has not yet been achieved, the subroutine “focus lens drive” for performing focus drive of the lens barrel 14 is executed based on the defocus amount obtained by the focus detection in step S50 (step S50). Step S140). This subroutine “focus lens driving” is executed by the Lμcom 36 in the lens barrel 14 in accordance with an instruction from the Bμcom 38, and its flowchart is as shown in FIG.

  That is, the Lμcom 36 receives the defocus amount and the type of the intermediate ring 90 read out in step S120 of the main flow through communication with the Bμcom 38 (step S150). Then, based on the received defocus amount, the focus lens drive amount and drive direction are calculated (step S152).

  Thereafter, the lens driving target position is calculated from the lens driving amount and driving direction and the current lens position, and the inflection point position is read from the memory element 88 according to the received type of the intermediate ring 90, and the calculated lens driving is performed. It is determined whether or not the target position is closer to the read inflection point position (step S154). If the lens drive target position is not closer to the inflection point position, the lens drive mechanism 18 drives the focus lens to the lens target position (step S156) and returns to the upper routine.

  On the other hand, when the calculated lens drive target position is closer to the inflection point position stored in advance in the memory element 88, the lens driving mechanism 18 drives the focus lens to the inflection point position (step). S158). Then, the equal-magnification macro area AF disable flag provided in the memory element 88 or provided in the memory (not shown) in the Bμcom 38 or the SDRAM 70 is set to “1” (step S160), and the process returns to the upper routine. .

  Thus, the Bμcom 38 discriminates the state of the equal-magnification macro area AF disabled flag so that the lens drive target position, which is the focus lens focusing position, is closer to the inflection point position (point C in FIG. 12). It can be determined whether or not there is (step S142). Here, when the equal-magnification macro area AF disable flag is “0”, that is, when the focus lens in-focus position is not closer to the inflection point position, the process returns to step S50 and in step S56. The focus adjustment operation is repeated until focus is achieved.

  On the other hand, when the same-magnification macro area AF disable flag is “1”, that is, when the focus lens in-focus position is closer to the inflection point position, the display in the finder and other displays The AF disabled display corresponding to the equal magnification macro area is performed (step S68), and this subroutine “AF” is terminated. This is a display indicating that AF cannot be performed in the same-magnification macro area, and a display different from the undetectable display in step S54, for example, a blinking display in a different cycle of the LED display in the finder is performed. This display has a meaning of prompting the photographer to perform focusing in MF because AF is impossible.

  FIG. 8B is a diagram showing an example of inflection point position data stored in the memory element 88 of the lens barrel 14. As shown in the figure, a plurality of inflection point position data DL1, DL2,..., DLn corresponding to the types 1, 2,..., N of the intermediate ring 90 when the intermediate ring 90 is mounted are stored.

  The Bμcom 38 determines the type of the intermediate ring 90 by communication with the mounted intermediate ring 90, and the Lμcom 36 selects the corresponding inflection point data from the data group of the memory element 88 as shown in FIG. The Bμcom 38 selectively reads out and uses the intermediate ring 90 according to the type.

  Thus, the present invention can be applied to a plurality of types of lens barrels 14 and intermediate rings 90.

  Adopting this method in the newly released lens barrel 14 is advantageous because it can cope with a new combination of the new lens barrel 14 and the intermediate ring 90 already on the market.

  As described above, even when the intermediate ring 90 is used, it is prohibited to drive the focus lens closer to the inflection point at which AF is impossible near the same magnification macro, and the situation is notified to the photographer. Will improve.

[Fourth Embodiment]
In the fourth embodiment, as shown in FIG. 11A, information on the inflection point position stored in the memory element 88 of the lens barrel 14 in the third embodiment is provided in the intermediate ring 90. The data is stored in a memory element (EEPROM or the like) 92.

  That is, in the present embodiment, the Bμcom 38 in the camera body 12, the memory element 92 in the intermediate ring 90, and the Lμcom 36 in the lens barrel 14 can communicate with each other, and exchange commands and data. be able to.

  The Lμcom 36 acquires information on the inflection point position stored in advance in the memory element 92 in the intermediate ring 90 by communication. Then, the lens driving mechanism 18 is controlled by comparing the position information of the focus lens with the inflection point position. That is, when the focus lens position is located closer to the inflection point position, the AF operation is prohibited and the lens driving mechanism 18 does not move the focus lens.

  In this way, in the vicinity of the equal magnification macro, the operation of moving the focus lens from the inflection point position to the near distance side by the AF operation is prohibited.

  Other configurations of the camera body 12 and the lens barrel 14 are the same as those in the first embodiment (FIG. 1). The main flow is the same as that of the second embodiment (FIG. 6). Further, the flow of the subroutine “AF” and the subroutine “focus lens driving” is the same as those in the third embodiment (FIGS. 9 and 10). Therefore, those descriptions are omitted.

  FIG. 11B is a diagram illustrating an example of inflection point position data stored in the memory element 92 of the intermediate ring 90. As shown in the figure, the memory element 92 has a plurality of inflection point position data DT1, DT2,... Corresponding to the types 1, 2,. DTn is stored.

  Therefore, the Lμcom 36 selectively reads out and uses the inflection point data corresponding to the lens barrel 14 from the data group of the memory element 92 in the intermediate ring 90 as shown in FIG.

  Thus, the present invention can be applied to a plurality of types of lens barrels 14 and intermediate rings 90.

  Adopting this method in the newly released intermediate ring 90 is advantageous because it can cope with a new combination of the new intermediate ring 90 and the lens barrel 14 that has already been released.

  As described above, even when an intermediate ring is used, the focus lens drive closer to the inflection point position is prohibited in the AF operation near the same magnification macro, and the situation is notified to the photographer. , Improve usability.

  The same effect can be obtained by combining a plurality of types of photographing lenses and intermediate rings.

  As described above, in the region where the AF operation cannot be normally performed in the vicinity of the equal-magnification macro region (point C to point B in FIG. 12), the focus lens position of point C, which is an inflection point, is detected, and focus is determined from point C. Since the prohibited area is set so as not to extend the lens, the photographer does not feel uncomfortable.

  In addition, when the focus lens is located near the inflection point, the photographer is notified by a display in the finder, etc., so that it is possible to focus by switching to the MF mode when focusing is desired at the B point. good.

  The same effect can be obtained when an intermediate ring is used.

  Alternatively, the inflection point position can be stored in the taking lens or the intermediate ring at the time of manufacture, and the focus lens driving near the inflection point can be prohibited during AF, and the situation can be notified to the photographer. Will improve.

  Even if a plurality of types of photographing lenses and intermediate rings are used in combination, the above effect can be obtained.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

  For example, as an embodiment of the focus adjustment apparatus of the present invention, a camera system having an image sensor has been described as an example, but the present invention is not limited thereto.

FIG. 1 is a block diagram showing a system configuration of a digital camera as a camera having a focus adjusting apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view schematically showing an internal configuration of a camera body cut away in order to show the configuration of the camera according to the first embodiment. FIG. 3 is a flowchart illustrating a main flow executed by Bμcom of the camera according to the first embodiment. FIG. 4 is a flowchart for explaining details of the subroutine “AF” in FIG. 3. FIG. 5 is a flowchart for explaining details of the subroutine “inflection point detection” in FIG. 4. FIG. 6 is a flowchart of a main flow executed by Bμcom of the camera having the focus adjustment apparatus according to the second embodiment of the present invention. FIG. 7 is a flowchart for explaining details of the subroutine “AF” in FIG. 6. FIG. 8A is a block diagram for explaining a characteristic part of a camera having a focus adjustment apparatus according to the third embodiment of the present invention, and FIG. 8B is stored in a memory element of a lens barrel. It is a figure which shows an example of the inflection point position data. FIG. 9 is a flowchart illustrating details of the subroutine “AF” in the camera according to the third embodiment. FIG. 10 is a flowchart for explaining details of the subroutine “focus lens driving” in FIG. 9. FIG. 11A is a block configuration diagram for explaining a characteristic part of a camera having a focus adjustment apparatus according to the fourth embodiment of the present invention, and FIG. 11B is stored in a memory element of an intermediate ring. It is a figure which shows an example of the inflection point position data. FIG. 12A is a diagram showing the relationship between the focus lens extension amount and the defocus amount of the photographic lens in the vicinity of the equal magnification macro region, and FIG. 12B is a diagram showing the relationship between the focus lens extension amount and the imaging magnification. .

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... Camera, 12 ... Camera body, 14 ... Lens barrel, 16 ... Shooting optical system, 18 ... Lens drive mechanism, 20 ... Image sensor, 22 ... Shooting optical system mounting part, 24 ... Release button, 26 ... Viewfinder device, 26A ... Reflector, 26B ... Pentaprism, 26C ... Eyepiece, 28 ... Shutter unit, 30 ... Dust filter, 32 ... Imaging unit, 34 ... Main circuit board, 36 ... Microcomputer for lens control (L [mu] com), 38 ... Body Microcomputer for control (Bμcom), 40 ... Communication connector, 42 ... Aperture, 44 ... Aperture drive mechanism, 46 ... Submirror, 48 ... AF sensor unit, 50 ... AF sensor drive circuit, 52 ... Mirror drive mechanism, 54 ... Shutter charge Mechanism 56 ... shutter control circuit 58 ... photometry circuit, DESCRIPTION OF SYMBOLS 0 ... Piezoelectric element, 62 ... Dust-proof filter drive circuit, 64 ... Temperature measurement circuit, 66 ... Interface circuit, 68 ... Liquid crystal monitor, 70 ... SDRAM, 72 ... FlashROM, 74 ... Recording media, 76 ... Image processing controller, 78 ... Non-volatile 80, LCD for operation display, 82 ... Camera operation switch (SW), 84 ... Battery, 86 ... Power supply circuit, 88, 92 ... Memory element, 90 ... Intermediate ring.

Claims (3)

A photographic lens that includes a focus lens and forms an optical image of the subject;
A main body to which the above photographing lens can be attached;
An intermediate ring that can be mounted between the photographic lens and the main body;
Comprising
The above photographic lens
Storage means for storing information relating to a region in which movement of the focus lens is prohibited , including the position of the focus lens corresponding to the same magnification macro corresponding to the type of the intermediate ring when the intermediate ring is mounted ;
The movement of the focus lens is controlled based on an instruction from the main body, and the information based on the information on the region where the movement of the focus lens is prohibited according to the type of the attached intermediate ring output from the storage means. Control means for controlling the movement of the focus lens into a region where the movement of the focus lens including the position of the focus lens corresponding to the same magnification macro is prohibited ;
A camera having a focus adjustment device. A photographic lens that includes a focus lens and forms an optical image of the subject;
A main body to which the above photographing lens can be attached;
An intermediate ring that can be mounted between the photographic lens and the main body;
Comprising
The intermediate ring stores information relating to a region in which movement of the focus lens is prohibited , including the position of the focus lens corresponding to the same magnification macro corresponding to the type of the photographing lens when the photographing lens is mounted. Have
The photographing lens controls the movement of the focus lens based on an instruction from the main body , and prohibits the movement of the focus lens according to the type of the photographing lens from the storage unit of the attached intermediate ring. Information on the area is acquired, and control is performed so as to prohibit the movement of the focus lens into an area where the movement of the focus lens including the position of the focus lens corresponding to the equal magnification macro is prohibited based on the information. A camera having a focus adjustment device characterized by having control means for controlling the focus. The main body has display means for displaying a result of the focus adjustment operation ,
The display unit, when the photographic lens is performed an operation for prohibiting the movement of the focus lens to the area to prohibit the movement of the focus lens, according to claim 1, characterized in that a warning display or A camera having the focus adjustment device according to 2 .

Images