JP2012133041A - Imaging apparatus, lens system and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow more accurate determination on proximity photographing.SOLUTION: Based on positions of a zoom lens and a focus lens, it is automatically determined whether to perform close-up photographing on the tele-side and the movable range of the focus lens is changed.

Description

  The present invention relates to an imaging apparatus having a so-called telemacro shooting mode, a lens, and a control method thereof, which can perform close-up shooting (macro shooting) on the telephoto side (telephoto side).

  As an imaging device such as a digital video camera or a digital still camera, an imaging device having a so-called telemacro shooting function that enables selection of a macro shooting mode capable of focusing on a close subject that cannot be focused in the normal shooting mode on the telephoto side. There is a device. In such an imaging apparatus, a photographer measures the distance to a subject and selects which shooting mode to use via a selection button or the like. In addition, there is a method in which a warning is displayed when focusing cannot be performed in the normal shooting mode, and the photographer is prompted to switch the shooting mode (see, for example, Patent Document 1).

JP 2003-241069 A

  However, in the above-mentioned document 1, in an imaging device having a telemacro shooting function, the selection of the normal shooting mode or the telemacro shooting mode is left to the photographer, which reduces the convenience of the photographer. In addition, the photographer may forget to select the telemacro shooting mode even though the subject is in the close position.

  The present invention has been made in view of the above problems, and an imaging apparatus having a telemacro shooting mode automatically switches to the telemacro shooting mode, that is, automatically determines the close-up shooting on the tele side. For the purpose.

  In order to achieve the above object, the technical features of the present invention include a control step for controlling the zoom lens for performing zooming operation and the focus lens for performing focus adjustment to move in the optical axis direction, respectively. The movable range of the focus lens on the telephoto side with respect to the predetermined zoom lens position is switched between a first range and a second range that is set to include the first range and further extend to the closest side. A switching step, and in the switching step, when the zoom lens is moved beyond a predetermined position to the telephoto side, the position of the zoom lens, the position of the focus lens, and the storage means are stored. The subject distance is determined according to information on the position of the focus lens for obtaining focus at the position of the zoom lens that changes according to the subject distance. It is determined whether the close side than the object distance, and switches the movable range of the focus lens in accordance with the determination result.

  According to the present invention, it is possible to automatically switch to the telemacro mode by determining whether close-up shooting is performed automatically without requiring an operation switching by a photographer. When making a decision, the zoom lens position information and subject distance information can be used to make it possible to make a more accurate close-up shot decision and suppress the occurrence of switching to the telemacro mode against the photographer's intention to shoot. Is possible.

System Configuration Focus position relationship diagram of focus lens and zoom lens Diagram showing focus lens tracking method Diagram showing focus lens position identification and subject distance calculation by interpolation method Table data for in-focus locus information Relationship diagram between focus lens and focus signal Diagram showing how to identify the in-focus locus during zoom movement The figure which showed the focus locus identification method using the center movement during zoom movement Flow chart of determination processing according to focus mode Flowchart of close-up shooting determination during zoom movement in MF mode Telemacro mode determination flowchart Display in telemacro mode Close-up shooting determination flowchart during zoom movement in AF mode The figure which showed the movement locus of the focus lens during zoom movement at the time of tele macro judgment

  Hereinafter, embodiments will be described with reference to the drawings.

<Device configuration>
FIG. 1 shows a configuration of a video camera as an imaging apparatus equipped with a lens system including a zoom lens unit and a focus lens unit. In addition, this embodiment is applicable not only to a video camera but to various imaging devices, such as a digital still camera.

  Reference numeral 101 denotes a front lens unit 101 and 102 which are fixed, a zoom lens unit which moves in the optical axis direction to perform a zooming operation, 103 denotes a diaphragm, and 104 denotes a fixed lens unit which is fixed. Reference numeral 105 denotes a focus lens unit that has a focus adjustment function and a compensator function that corrects image plane movement due to zooming, and moves behind the zoom lens unit in the optical axis direction. The photographing optical system composed of these lens units is a rear focus lens type optical system composed of four lens units having positive, negative, positive and positive optical powers in order from the object side (left side in the figure). is there. In the drawing, each lens unit is described as being configured by a single lens, but in actuality, it may be configured by a single lens or by a plurality of lenses. It may be configured. Hereinafter, the zoom lens unit 102 is simply referred to as a zoom lens 102, and the focus lens unit 105 is simply referred to as a focus lens 105.

  Reference numeral 106 denotes an image sensor constituted by a CCD or CMOS sensor. A light beam from a subject that has passed through the photographing optical system is incident on the image sensor 106. The image sensor 106 photoelectrically converts incident subject image light and outputs an image signal. The imaging signal is amplified to an optimum level by an amplifier (AGC) 107 and input to the camera signal processing circuit 108. The camera signal processing circuit 108 converts the input imaging signal into a standard television signal, which is sent to the monitor device 109 and displayed as a captured image. The monitor device 109 also displays an image that informs the photographer of the shooting mode, warning, and the like.

  The output signal of the amplifier (AGC) 107 is also input to the AF signal processing circuit 112. The AF signal processing circuit 112 detects an AF evaluation signal corresponding to the contrast of the captured image that is the focus signal of the focus lens 105. The AF evaluation signal (sharpness signal) generated by the AF signal processing circuit 112 is read as data by communication with the system microcomputer 113.

  The system microcomputer 113 outputs a signal for moving the zoom lens 102 in the tele direction (telephoto side) or the wide direction (wide angle side) corresponding to the direction in which an operation member (not shown) such as a zoom switch is operated. . As a result, the zoom lens 102 is moved in this direction via the zoom drive source 110. Further, the system microcomputer 113 performs a so-called AF operation in which the focus lens 105 is moved and brought into focus via the focusing drive source 111 based on the AF evaluation signal obtained from the AF signal processing circuit 112.

  In addition, the system microcomputer 113 includes a shooting state determination unit 115 that determines whether or not telemacro shooting is to be performed based on the movement history of the focus lens 105. If it is determined that telemacro shooting is being performed, the moving range switching unit 114 adds the moving range (movable range) of the focus lens 105 to the moving range in the normal shooting mode, and further expands to the near side. Switch to the movement range at. Furthermore, the shooting status determination unit 115 causes the monitor device 109 to display a display for notifying the photographer of the determination status.

<Operation range of zoom lens and focus lens>
Next, the operation area in the normal shooting mode and the tele macro shooting mode in the position space composed of the moving range of the zoom lens 102 and the moving range of the focus lens 105 in the camera of the present embodiment will be described with reference to FIG. In this position space, the moving range of the zoom lens 102 is set on the horizontal axis, the left direction is set to the wide side, and the right direction is set to the tele side. Further, the movement range of the focus lens 105 is set on the vertical axis, and the downward direction is set to the far distance (infinity) side, and the upward direction is set to the near distance (closest) side. In the drawing, a curved line L1 indicates a locus of points formed by a combination of a zoom lens position and a focus lens position that focuses on a subject at infinity. A curved line L2 indicates a locus of a point formed by a combination of a zoom lens position and a focus lens position that is focused on the shortest shooting distance (for example, 1 cm) at the wide end. A curve L3 indicates a locus of a point formed by a combination of a zoom lens position and a focus lens position that is focused on the shortest shooting distance (for example, 1 m) at the tele end in the normal shooting mode. A straight line L4 indicates a movement limit (closest end) on the closest side of the focus lens 105 with the maximum point of the curve L3 as a limit. ZoomTh indicates the zoom lens position that is the maximum point of the curve L3. In the normal shooting mode, the area is surrounded by the curves L1, L2, L3, and L4 (closest end). In the normal shooting mode, the focus lens position can be adjusted in the normal shooting area.

  In addition, the telemacro imaging region is provided in a region surrounded by the curve L3 and the closest end of the focus lens 105 on the telephoto side from the zoom lens position ZoomTh where the curve L3 becomes maximum as shown in the figure. In the telemacro shooting area, the shortest shooting distance becomes closer as it goes to the wide side. Therefore, when focusing at the tele end and zooming to the wide side, it becomes impossible to focus on the way. In this way, the telemacro imaging area is an area set so as to extend further to the closer side than in the normal imaging area.

<Focus lens tracking method>
FIG. 3 is a diagram for explaining an example of a locus tracking method of the focus lens 105 in the inner focus type lens system.

  3, Z0, Z1, Z2,... Z6 indicate positions of the zoom lens 102. a0, a1, a2,... a6 and b0, b1, b2,... b6 are positions of the focus lens 105 according to the subject distance stored in advance in a microcomputer (not shown). A collection of these focus lens positions (a0, a1, a2,... A6 and b0, b1, b2,... B6) is a focus locus (representative locus) that the focus lens 105 should follow for each representative subject distance. )

Further, p0, p1, p2,... P6 are positions on the in-focus locus that should be followed by the focus lens 105, calculated based on the two representative loci. A formula for calculating the position on the in-focus locus is shown below.
p (n + 1)
= | P (n) -a (n) | / | b (n) -a (n) | × | b (n + 1) -a (n + 1) | + a (n + 1) (1)
According to the above equation (1), for example, when the focus lens 105 is at p0 in FIG. 3, the ratio that p0 internally divides the line segment b0-a0 is obtained.
A point that internally divides the line segment b1-a1 according to this ratio is defined as p1. From the positional difference between p1 and p0 and the time required for the zoom lens 102 to move from Z0 to Z1, the moving speed of the focus lens 105 for maintaining focus can be found.

  Next, a case where there is no restriction that the stop position of the zoom lens 102 is on the boundary of the zoom area having the stored representative trajectory data will be described. FIG. 4 is a diagram for explaining an interpolation method in the moving direction of the zoom lens 102. A part of FIG. 3 is extracted and the position of the zoom lens 102 is made arbitrary.

In FIG. 4, the vertical axis indicates the position of the focus lens 105, and the horizontal axis indicates the position of the zoom lens 102. When the focus lens position on the representative locus stored in the microcomputer (not shown) is set to Z0, Z1,... Zk-1, Zk,. ,
a0, a1, ... ak-1, ak ... an
b0, b1,... bk-1, bk.
It is said.

Now, when ax and bx are obtained when the zoom lens position is in Zx not on the zoom area boundary and the focus lens position is px,
ax = ak− (Zk−Zx) × (ak−ak−1) / (Zk−Zk−1) (2)
bx = bk− (Zk−Zx) × (bk−bk−1) / (Zk−Zk−1) (3)
It becomes.

  That is, according to the internal ratio obtained from the current zoom lens position and the two zoom area boundary positions (for example, Zk and Zk-1 in FIG. 4), the stored four representative trajectory data (in FIG. 4). Ak, ak-1, bk, bk-1) of the same subject distance are internally divided by the above-mentioned internal ratio. Thereby, ax and bx can be obtained.

  Then, according to the internal ratio obtained from ax, px, and bx, among the four representative data stored in advance, the data with the same focal length is internally divided at the above internal ratio as shown in equation (1). Thus, pk and pk-1 can be obtained.

  When zooming from wide to tele, the moving speed of the focus lens 105 is determined based on the difference between the focus lens position pk to be followed and the current focus lens position px and the time required for the zoom lens 102 to move from Zx to Zk. I understand. The moving speed of the focus lens 105 is a time necessary for maintaining the focus.

When zooming from tele to wide,
The moving speed of the focus lens 105 can be determined from the difference between the focus lens position pk-1 to be followed and the current focus lens position Px and the time required for the zoom lens 102 to move from Zx to Zk-1. The moving speed of the focus lens 105 is a time necessary for maintaining the focus.

  FIG. 5 shows an example of table data of in-focus locus information stored in advance in a microcomputer (not shown). FIG. 5 shows focus lens position data A (n, v) for each subject distance, which varies depending on the zoom lens position.

  The subject distance changes in the column direction of the variable n, and the zoom lens position (focal length) changes in the row direction of the variable v. Here, n = 0 represents a subject distance at infinity, and the subject distance changes to the closest distance side as n increases. n = m indicates a subject distance of 1 cm.

  On the other hand, v = 0 represents the wide end. Furthermore, the focal length increases as v increases, and v = s represents the zoom lens position at the tele end. Therefore, one representative trajectory is drawn with one column of table data.

  Next, a method for calculating the subject distance will be described with reference to FIG.

Trajectories Dn, Dn-1, and Dx are in-focus trajectories for each subject distance. When calculating the subject distance, if the focus lens 105 is not on the stored representative trajectory data, the subject distance is calculated using interpolation calculation. Dx as shown below
= | Px-ax | / | bx-ax | × | Dn-1−Dn | + Dn (4)
According to the above equation (4), for example, when the focus lens 105 is at px in FIG. 4, the ratio by which px internally divides the line segment bx-ax is obtained, and the line segment Dn-1-Dn is internally divided according to this ratio. Let Dx be the point to do.

  In this way, the subject distance can be calculated from the zoom lens position, the focus lens position, and the focus locus (representative locus).

  Next, a trajectory tracking method for solving the problem that it becomes difficult to know which trajectory the focus lens 105 should follow during zooming from wide to telephoto will be described. The focus lens 105 in focus is dense on the wide side, but it is far away on the tele side, so it may not be clear which trajectory to follow when zooming from wide to tele.

  First, the relationship between the AF evaluation signal and the focus lens 105 is as shown by a curve E1 in FIG. This AF evaluation signal indicates the level of the high-frequency component (sharpness signal) of the imaging signal. A point P at which the AF evaluation signal reaches a peak is a focus position of the focus lens 105.

  Therefore, by continuing to maintain the focus lens 105 at the peak (point P) of the AF evaluation signal, it is possible to solve the problem that it is not possible to know which locus should be followed during zooming. However, the peak of the AF evaluation signal is a relative value, and the value sequentially changes due to a change in the angle of view due to zooming and a change in the contrast of the subject. Therefore, the direction in which the peak of the AF evaluation signal exists can be determined by moving the focus lens 105 minutely in the infinity / closest direction and observing the change of the AF evaluation signal.

  In the curve E1 of FIG. 6, when the lens is moved slightly around the point A and the point B, the AF evaluation signal repeatedly increases and decreases and shows a large fluctuation. Since the peak of the AF evaluation signal exists in the increasing direction of the AF evaluation signal at the time of minute movement, the peak of the AF evaluation signal can be specified by moving the focus lens 105 in the increasing direction. On the other hand, when the focus lens 105 is slightly moved at the point P, the fluctuation of the AF evaluation signal becomes a small value.

  In FIG. 7A, it is assumed that a focus locus (collection of focus lens positions) that the focus lens 105 should follow when zooming while focusing on a subject located at a certain distance is 1900. Here, assuming that the center focus locus of the minute movement is 1900, the minute movement of the focus lens 105 will be described. When the focus lens 105 is at a position F0 that is L away from the center focus locus on the infinite side, an AF evaluation signal at F0 is acquired. For this purpose, the focus lens 105 is moved to F1 (a point that is infinitely separated by L from the center focus locus) with the same inclination as 1900, and an AF evaluation signal E0 is obtained.

  Next, since 1900 is the center focus locus, the focus lens 105 is moved to a point F2 that is 1 L away from 1900.

  Next, in order to acquire the AF evaluation signal at F2, the focus lens 105 is moved to F3 (a point L away from the center focus locus) with the same inclination as 1900, and an AF evaluation signal E1 is obtained. Similarly, the focus lens 105 is moved to a point F4 that is L away from the center focus locus 1900 toward the infinity side. By repeating this operation, a minute movement around 1900 becomes possible.

  As described above, the movement of the focus lens 105 has a focus locus of 1900 to be traced, and the AF evaluation signals E0, E1, E2,... Obtained by the minute movement are shown in FIG. As shown in FIG. That is, zooming is performed while maintaining focus.

  However, the center focus locus is not always the focus locus that should be followed. Such a case will be described with reference to FIG. First, when the focus lens 105 is at the position of F′0, the above-described minute movement is performed around the temporary center focus locus 1901. When moving from F'0 to F'5, AF evaluation signals E'0, E'2, and E'4 on the orbit are stored. Here, the next focus lens position F′6 is determined by comparing the AF evaluation signals.

  When the AF evaluation signal has a value as shown in FIG. 8B, since E′0 <E′2 and E′4 <E′2, the peak of the AF evaluation signal is in the direction of E′2, that is, It can be seen that there is a focus locus to be traced to the closest side.

  Therefore, the position of F′6 is moved closer to the closest side by W (center movement) than the temporary center focus locus 1901. Then, the minute movement is performed again using the in-focus locus 1902 that is closer to W by 1901 as a temporary central in-focus locus.

  Similarly, the above-mentioned minute movement is performed several times around the temporary center focus locus 1902, and the AF evaluation signals are compared. Based on the result, the center movement amount W is set, and the focus transfer is repeated until the focus locus can be identified.

  In this way, based on the AF evaluation signal obtained by the minute movement, the focus locus where the AF evaluation signal becomes substantially constant is specified while changing over the center focus locus during zooming. As a result, it is possible to solve the problem that it is impossible to know which locus the focus lens 105 should follow when zooming from wide to tele.

  The zooming control described above is generally performed in synchronization with the vertical synchronization signal of the video because of focus detection using the image pickup signal from the image pickup device.

  Note that there are cases where there is no clear peak even when the focus lens 105 is moved infinitely from the closest position and the AF evaluation signal at the time of the movement is illustrated as shown by a curve E2 in FIG. This occurs when the subject has a low contrast. In this case, it is difficult to specify the focus position, and the focus lens 105 may reciprocate around the point P without specifying the peak. As described above, when the threshold value of the AF evaluation signal for which a sufficient focus position cannot be specified is Eth, and the AF evaluation signal is lower than Eth, it is determined that the in-focus state is not achieved.

  Similarly, during zooming, a sufficient AF evaluation signal cannot be obtained when the lens is moved close and infinitely. If the AF evaluation signal is equal to or less than Eth, it is determined that the in-focus state is not achieved.

<Photographing situation determination method and control after determination>
Next, a shooting situation determination method and control after determination performed in the system microcomputer 113 will be described. FIG. 9 shows a flowchart of processing in the MF mode and the AF mode. The series of processes shown in FIG. 9 is executed in synchronization with the vertical synchronization signal and executed once per vertical synchronization time (1 V) according to the computer program stored in the system microcomputer 113.

  STEP 301 determines the focus mode. If the camera setting is in the MF mode, the process proceeds to STEP 302. If the camera setting is in the AF mode, the process proceeds to STEP 303.

  STEP 302 is a process for determining the close-up shooting in the MF mode, and details will be described with reference to the flowchart of FIG.

  STEP 303 is a process for determining the close-up shooting in the AF mode, and details will be described with reference to the flowchart of FIG.

  STEP 304 is processing for performing telemacro mode determination, and details will be described with reference to the flowchart of FIG.

<Close-up shooting determination during zoom movement in MF mode>
Next, FIG. 10 shows a flowchart of the close-up shooting determination at the time of zoom movement in the MF mode, which is one of the flows of the telemacro shooting determination control of the present embodiment.

  STEP 401 determines the zoom lens position. The zoom lens position is determined using the ZoomTh position as a boundary. If the zoom lens position is wider than ZoomTh, the process proceeds to STEP 402. If the zoom lens position is on the tele side with respect to ZoomTh, the process proceeds to STEP 406, the close-up shooting flag is turned off, and the process ends.

  STEP 402 determines the moving direction of the zoom lens 102. When the moving direction of the zoom lens 102 is the tele direction, the process proceeds to STEP 403. If the moving direction of the zoom lens 102 is the wide direction, the process proceeds to STEP 406, the close-up shooting flag is turned off, and the process ends.

  In step 403, the position of the focus lens 105 is determined. The fact that the focus lens 105 reaches the straight line L4 during the movement of the zoom lens 102 means that the zoom lens 102 is photographing a subject closer than 1 m on the wide side. Therefore, when the position of the focus lens 105 reaches L4, the process proceeds to STEP 404. If the position of the focus lens 105 does not reach L4, the process proceeds to STEP 406, the close-up shooting flag is turned off, and the process ends.

  In STEP 404, the subject distance is calculated. The subject distance is calculated by performing interpolation calculation according to equation (4). When the focus lens 105 reaches the 1m focus limit L4, the subject distance is specified by performing interpolation calculation from the focus locus traced just before. This subject distance is the subject distance to be traced when the zoom lens position is zoomed to the tele side from ZoomTh. When the calculation is completed, the process proceeds to STEP 405.

  STEP 405 performs a close-up shooting flag ON setting process. Based on this close flag, a telemacro determination process described later is performed. The close-up shooting flag is a signal composed of 0 and 1. The initial value is 0, and when it is determined that the close-up shooting is set, the close-up shooting flag is set to 1.

  STEP 406 performs a close-up shooting flag OFF setting process. Based on this close flag, a telemacro determination process described later is performed. The close-up shooting flag is a signal composed of 0 and 1. The initial value is 0. If it is determined that the close-up shooting is not performed, the close-up shooting flag is set to 0.

<Tele-macro mode judgment>
Next, FIG. 11 shows a flowchart of telemacro determination, which is one of the flows showing the flow of telemacro shooting determination control of the present embodiment.

  STEP 501 determines whether a telemacro mode flag described later is ON / OFF. This telemacro mode flag is a flag indicating whether or not the telemacro mode is set. If this telemacro mode flag is once turned on, the process proceeds to STEP 506. If the telemacro mode flag is OFF, the process proceeds to STEP 502.

  STEP 502 determines whether the close-up shooting flag is ON / OFF. As described with reference to the flowchart of FIG. 10, the close-up flag is a flag that indicates whether or not close-up shooting at the time of zooming is performed. If the close-up shooting flag is ON, the process proceeds to STEP 503. If the close-up shooting flag is OFF, the process ends.

  STEP 503 determines whether or not the zoom lens position has exceeded ZoomTh, which is the position of the 1m focus peak. When the zoom lens position exceeds ZoomTh, the zoom lens position enters the telemacro imaging region shown in FIG. 2, and thus the focus limit needs to be changed. Therefore, when the zoom lens position exceeds ZoomTh, the process proceeds to STEP 504 in order to set the telemacro mode flag. If the zoom lens position does not exceed ZoomTh, it is not in the telemacro area, and the process is terminated.

  STEP 504 is processing for setting a telemacro mode flag indicating ON for telemacro shooting to ON. The telemacro mode flag is a signal composed of 0 and 1. The initial value is set to 0. When it is determined that the close-up shooting and the zoom lens 102 are on the tele side from ZoomTh, the telemacro mode flag is set to 1, and the process proceeds to STEP 505. Transition processing.

  STEP 505 is processing for canceling the limiter of the focus lens 105 and permitting movement of the telemacro region in FIG.

  When the close-up shooting is performed and the zoom lens 102 moves to the tele side beyond ZoomTh, the photographer determines that he / she wants to perform telemacro shooting. Then, the limit of the focus lens 105 is changed from the limit of the normal shooting area to the limit of the telemacro shooting area, and the focus can be moved to the 1 m focusing limit L4 on the tele side.

  On the other hand, STEP 506 determines whether the position of the zoom lens 102 is wider than the 1 m focus peak. When the telemacro mode flag is ON and the zoom lens position is outside the telemacro region, the telemacro mode flag is automatically set to OFF after a predetermined time. Therefore, when the position of the zoom lens 102 is on the wide side from the 1 m focusing peak ZoomTh, the process proceeds to STEP 507. When the position of the zoom lens 102 is not on the wide side from the 1 m focusing peak ZoomTh, the process proceeds to STEP 509.

  STEP 507 is a process for incrementing the telemacro mode timeout count. The timeout counter is a counter that starts from an initial value of 0, and performs a process of incrementing the count by one process. After the processing is completed, the process proceeds to STEP 508.

  STEP 508 determines whether the value of the timeout count is greater than a certain threshold Th. This threshold value Th can be arbitrarily set, and is a time to cancel the telemacro mode depending on the time when the zoom lens 102 is on the wide side from ZoomTh after the transition to the telemacro mode. Note that the threshold Th is set to a value at which the telemacro mode is not canceled at a timing not sufficiently intended by the photographer after sufficient verification. In this embodiment, it is set to 2 seconds. If the time-out counter is 2 seconds or less, the process proceeds to STEP 511. If 2 seconds or more have elapsed, the process proceeds to STEP 509.

  STEP 509 is processing for setting a telemacro mode flag indicating that telemacro shooting is OFF. The telemacro mode flag is a signal composed of 0 and 1, and when the zoom lens position moves to the wide side from ZoomTh within a predetermined time while the close-up shooting flag is ON, the telemacro mode flag is set to 0 and the process proceeds to STEP510. Transition.

  STEP 510 is a process for setting the limiter of the focus lens 105 again and prohibiting the movement of the telemacro region in FIG. If the zoom lens 102 moves to the wide-angle side beyond ZoomTh in a state where the telemacro shooting is being performed, the photographer determines that the telemacro shooting is to be ended. Then, the limit of the focus lens 105 is changed from the limit of the telemacro shooting area to the limit of the normal shooting area, and on the telephoto side, it is limited to 1 m subject shooting. After the processing is completed, the process proceeds to STEP511.

  STEP 511 is a process for performing display setting of the telemacro icon. The telemacro icon switches between display / non-display according to the telemacro mode flag. An example of the display is shown in FIG. When the close-up subject 122 is photographed, if the zoom lens 102 is moved and zoomed to the tele side beyond ZoomTh, a telemacro icon 121 indicating that the telemacro mode photographing with the focus lens 105 being released is displayed is displayed. . At the time of display, the system microcomputer 113 transmits a display request to the photographing information display process, and controls the display of the telemacro icon on the display in the photographing information display process.

  By performing the above processing, it is possible to switch to the telemacro mode by automatically determining the close-up shooting without switching the operation by the photographer in the MF mode. At the time of determination, by using the position information of the zoom lens 102 and the subject distance information, it is possible to determine a more accurate close-up shooting, and suppress the occurrence of switching to the telemacro mode against the photographer's shooting intention. It becomes possible. Thereby, normal control can be performed with priority given to focus responsiveness to changes in the subject distance such as camera work.

<Tele-macro judgment in AF mode>
Next, close-up shooting determination processing in the AF mode will be described.
FIG. 13 shows a flowchart of telemacro determination in the AF mode, which is one of the flows showing the flow of telemacro shooting determination control of the present embodiment.

  STEP 1301 determines the zoom lens position. The zoom lens position is determined using the ZoomTh position as a boundary. If the zoom lens position is wider than ZoomTh, the process proceeds to STEP 1302. If the zoom lens position is on the tele side of ZoomTh, the process proceeds to STEP 1307, the close-up shooting flag is turned off, and the process ends.

  STEP 1302 determines the moving direction of the zoom lens 102. When the moving direction of the zoom lens 102 is the tele direction, the process proceeds to STEP 1303. When the moving direction of the zoom lens 102 is the wide direction, the process proceeds to STEP 1307, the close-up shooting flag is turned off, and the process ends.

  In STEP 1303, the subject distance is calculated. The subject distance is calculated by performing interpolation calculation according to equation (4). However, the focus lens position used for the calculation uses the center focus locus and performs interpolation calculation to specify the subject distance. This subject distance is the subject distance to be traced when the zoom lens position is zoomed to the tele side from ZoomTh. When the calculation is completed, the process proceeds to STEP 1304.

  STEP 1304 determines whether the subject distance is less than 1 m. If the subject distance calculated in STEP 1303 is closer than 1 m which is the threshold for close-up shooting, the process proceeds to STEP 1305, and if it is on the infinite side from 1 m, the process proceeds to STEP 1307.

  STEP 1305 determines whether or not the subject is in focus. As described above, the in-focus position during zooming is determined by detecting the increase or decrease of the AF evaluation signal and moving the focus lens 105 in the direction in which the AF evaluation signal increases. However, as described with reference to FIG. 6, the subject with low contrast has a low AF evaluation signal and no peak. Therefore, in the case of a subject whose AF evaluation signal is lower than the AF evaluation signal Eth, even if the subject distance is closer than 1 m, the subject may not be in focus when the AF evaluation signal is low. That is, since there is a possibility that the photographer has not photographed the closest subject, it is determined that the photographing is not close. Therefore, the process transitions to STEP 1307. On the other hand, when a sufficient AF evaluation signal is obtained, it is determined that the in-focus state is obtained, and the process proceeds to STEP 1306. This in-focus state determination method is one of a plurality of determination methods, and other methods may be used.

  In STEP 1306, close-up shooting flag ON setting processing is performed. Based on this close flag, a telemacro determination process described later is performed. The close-up shooting flag is a signal composed of 0 and 1. The initial value is 0, and when it is determined that the close-up shooting is set, the close-up shooting flag is set to 1.

  STEP 1307 performs a close-up shooting flag OFF setting process. Based on this close flag, a telemacro determination process described later is performed. The close-up shooting flag is a signal composed of 0 and 1. The initial value is 0. If it is determined that the close-up shooting is not performed, the close-up shooting flag is set to 0.

  This completes the close-up shooting determination in the AF mode.

  After the closeness determination process is completed, the process proceeds to the telemacro mode determination process in the same manner as the MF mode.

<Actual focus lens movement for telemacro judgment>
Next, the actual movement of the focus lens 105 in the AF macro telemacro determination described with reference to FIG. 13 is shown in FIG.

  FIG. 14 shows the movement of the focus lens 105 indicated by solid arrows L6 to L8 when a subject of about 70 cm is zoomed from the wide end to the tele end in the AF mode. This is based on the assumption that the photographer zooms to further enlarge the subject close to the camera. The effect of this embodiment will be described with reference to this figure. However, in the present embodiment, description will be made on the condition that there is no blurring during zooming.

  In this position space, the moving range of the zoom lens 102 is set on the horizontal axis, the left direction is set to the wide side, and the right direction is set to the tele side. Further, the movement range of the focus lens 105 is set on the vertical axis, and the downward direction is set to the far distance (infinity) side, and the upward direction is set to the near distance (closest) side. Since L1 to L4 are the same as those described with reference to FIG.

  A broken line L5 is in-focus locus information with a subject distance of 70 cm. When a 70 cm subject is photographed, the focus can be maintained by moving the focus lens 105 along this L5.

  First, L6 is a locus of the movement center of the focus lens 105 when zooming from the wide end. The focus lens 105 specifies the in-focus position while finely moving the focus lens 105 in the closest and infinite directions with respect to L6. When the distance L6 is moving, the subject distance is calculated from the position of the focus lens 105. Then, the subject distance immediately before L6 intersects with L4 is stored.

  When it is determined that the stored subject distance is 1 m or less, the closeness flag is set to ON. Since the focus lens 105 is in contact with the closest end L4, the focus lens 105 moves on L7. When moving on L7, when the zoom lens 102 is moved to the tele side with respect to ZoomTh, the telemacro mode flag is turned ON.

  When the telemacro mode flag is turned on, the limit of the focus lens 105 is expanded from L3 to L4 which is the closest end, and the close subject can be focused.

  At a point where L7 intersects with a focus locus with a subject distance of 70 cm, the focus lens 105 moves on L8, which is a focus locus with a subject distance of 70 cm. Then, as the zoom lens 102 reaches the tele end, the movement of the focus lens 105 is terminated, and normal AF mode processing is performed.

  Thus, the limit of the position of the focus lens 105 is changed according to the determination result of the close-up shooting, and the movable area of the focus lens 105 is expanded to the telemacro area. Thereby, it is possible to move on L8, which does not require operation switching by the photographer, and cannot be moved following in normal photographing. Further, in the determination, by using the position information of the zoom lens 102, the subject distance information, and the focus information, it becomes possible to determine the more accurate close-up shooting, and the telemacro mode is against the shooting intention of the photographer. It is possible to suppress the occurrence of switching.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

(Other embodiments)
The object of each embodiment is also achieved by the following method. That is, a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but the present invention includes the following cases. That is, based on the instruction of the program code, an operating system (OS) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  Furthermore, the following cases are also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the procedure described above.

101 Front lens unit 102 Zoom lens unit 103 Aperture 104 Fixed lens unit 105 Focus lens unit 106 Image sensor 107 AGC
DESCRIPTION OF SYMBOLS 108 Camera signal processing circuit 109 Monitor apparatus 110 Zoom drive source 111 Focusing drive source 112 AF signal processing circuit 113 System microcomputer 114 Moving range switching part 115 Shooting condition determination part

Claims (12)

Control means for controlling the zoom lens for zooming operation and the focus lens for focus adjustment to move in the optical axis direction, respectively;
Detecting means for detecting position information of the zoom lens and the focus lens;
Storage means for storing the position of the focus lens for obtaining focus at the position of the zoom lens according to the subject distance;
Switch for switching the movable range of the focus lens on the telephoto side from a predetermined zoom lens position between a first range and a second range that includes the first range and extends to the near side. Means,
When the zoom lens is moved beyond a predetermined position to the telephoto side, the switching unit is configured to change the subject according to the position of the zoom lens, the position of the focus lens, and information stored in the storage unit. An image pickup apparatus that determines whether or not the distance is closer to a predetermined subject distance and switches a movable range of the focus lens according to the determination result.   The imaging apparatus according to claim 1, wherein the switching unit determines whether or not the zoom lens has performed close-up shooting at a wide-angle side with respect to a predetermined position.   The switching means specifies a subject distance when the focus lens reaches the closest end when the zoom lens is on a wide-angle side from a predetermined position, and determines close-up shooting based on the subject distance. The imaging apparatus according to claim 2, wherein: Imaging means for capturing a subject image and outputting an imaging signal;
A focus adjusting unit that controls the focus lens based on a focus signal that is a sharpness signal extracted from the imaging signal and performs focus adjustment;
The switching means performs tracking of a focus position based on the focus signal when the zoom lens is moving, specifies a subject distance immediately before the zoom lens exceeds the predetermined position, and determines the subject distance. The image pickup apparatus according to claim 1, wherein the close-up shooting is determined on the basis of the image pickup device.   The switching means detects the focus signal when determining a subject distance and performing close-up shooting, and changes the determination result of close-up shooting when the focus signal is not in focus. Item 5. The imaging device according to Item 4.   6. The switch according to claim 1, wherein the switching unit switches the movable range of the focus lens from the first range to the second range when it is determined that close-up shooting is performed. The imaging device according to any one of the above.   The imaging device according to any one of claims 1 to 6, wherein when the switching unit determines that the close-up shooting is not performed, the movable range of the focus lens is set to the first range. .   The configuration of the zoom lens and the focus lens is a rear focus lens type, the shortest subject distance is different on the wide-angle side and the telephoto side of the zoom lens, and the shortest subject distance is larger on the wide-angle side than on the telephoto side. The imaging apparatus according to claim 1, wherein the imaging apparatus is closer.   The predetermined subject distance is a closest subject distance among subject distances that can maintain focus in the movable range of the zoom lens in the subject distance information stored in the storage unit. The imaging device according to any one of claims 1 to 8.   The predetermined position of the zoom lens is a position of the zoom lens that the focus lens extends to the nearest end among positions of the zoom lens stored in the storage unit. The imaging device according to claim 9. A control step for controlling the zoom lens for zooming operation and the focus lens for focus adjustment to move in the optical axis direction, respectively;
Switch for switching the movable range of the focus lens on the telephoto side from a predetermined zoom lens position between a first range and a second range that includes the first range and extends to the near side. And having steps,
In the switching step, when the zoom lens is moved beyond a predetermined position to the telephoto side, the zoom lens changes according to the position of the zoom lens, the position of the focus lens, and the subject distance stored in the storage unit. In accordance with the position information of the focus lens for obtaining the focus at the position of the zoom lens, it is determined whether or not the subject distance is closer to the predetermined subject distance, and according to the determination result A control method characterized by switching a movable range of the focus lens. A zoom lens for zooming,
A focus lens for adjusting the focus,
When the zoom lens is moved beyond a predetermined position to the telephoto side, the zoom lens changes according to the position of the zoom lens, the position of the focus lens, and the subject distance stored in the storage unit. The movable range of the focus lens is set so as to include the first range and the first range and further extend to the closest side according to the position information of the focus lens for obtaining focus at the position. The lens system is switched to the second range.

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