JP2006098676A - Autofocus camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve handleability and quick photographing performance by rapidly performing focusing operation in changing the posture of a camera. <P>SOLUTION: The autofocus camera has a focusing operation means for performing operation related to autofocus, a posture detection means for detecting the posture of the camera, and a detection means for detecting that the posture of the camera is changed from output from the posture detection means. The focusing operation means is actuated in response to detecting that the posture of the camera is changed. The operation of the focusing operation means is, for example, changing a selection area or focusing itself. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an autofocus camera, which improves the convenience of focusing accompanying a change in the posture of the camera.

  There is a camera that has a plurality of focus detection areas (ranging points) in the shooting screen, can select either one manually or automatically, and performs lens focus adjustment based on the focus adjustment information of the selected area. . In addition, considering that the alignment direction of the focus detection areas changes depending on whether the camera is held in the horizontal position or the vertical position, separate area selection algorithms for the horizontal position and the vertical position are prepared in advance. In some cases, the selection area is determined by an algorithm according to the camera posture detection result (see, for example, Patent Document 1).

JP-A-6-82678

  By the way, depending on the shooting situation, it is often unclear whether horizontal position shooting or vertical position shooting is good. In this case, the photographer searches for the best composition while changing the posture of the camera several times. However, when the camera of Patent Document 1 is used, the focus adjustment start operation (half-press operation) is performed every time the posture is changed. You have to start over. In other words, although the camera of Patent Document 1 changes the area selection algorithm between the vertical position and the horizontal position, an operation for that is always necessary to start a new focus adjustment.

An autofocus camera according to the present invention includes a focusing operation unit that performs an operation related to autofocus, a posture detection unit that detects the posture of the camera, and a detection unit that detects that the posture of the camera has been changed from the output of the posture detection unit. And the focusing operation means is operated in response to detection of a change in the posture of the camera.
Particularly, in the second and third aspects of the invention, the focusing operation means includes area selection means for selecting an area to be focused from a plurality of focus detection areas in the photographing screen, and the area selection means is determined in advance. If a posture change is detected when a focus detection area other than the reference area is selected, the selected area is changed to the reference area in response to the detection. The reference area is, for example, an area at the center of the screen.
According to a fourth aspect of the present invention, the focusing operation means includes area selection means for selecting an area to be focused from a plurality of focus detection areas in the photographing screen, and the area selection means responds to the detection of the posture change. The focus detection area having the closest positional relationship to the positional relationship on the screen of the selection area before the posture change is set as a new selection area.
In the invention of claim 5, the focusing operation means further includes a focus adjustment means for adjusting the focus of the lens based on the focus adjustment state of the selected area by the area selection means, the focus adjustment means responding to the detection of the posture change, The area selection means starts focus adjustment for the newly selected area.
According to the sixth and seventh aspects of the present invention, the focusing operation means includes focus adjustment means for adjusting the focus of the lens based on the focus adjustment state of the focus detection area in the photographing screen, and the focus adjustment means is responsive to a predetermined operation. When focus adjustment is started and a change in posture is detected thereafter, new focus adjustment is started in response to the detection. The focus adjustment performed in response to the predetermined operation and the focus adjustment performed in response to the posture change may be performed on the same focus detection area, or may be performed on different focus detection areas. .

  According to the present invention, since the focusing operation means is activated in response to the detection of the camera posture change, it is not necessary to perform the focus adjustment start operation every time the posture is changed, and the usability is improved. In addition, it is possible to increase the possibility of taking a photo opportunity.

-First embodiment-
A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view of a single-lens reflex digital still camera according to the present embodiment as viewed from the back side, where 10 indicates a camera body and 20 indicates a photographic lens attached to the body 10. On the rear surface of the camera body 10, an area selector (four-way button) 11 for selecting a focus detection area, a liquid crystal monitor 12 for displaying a captured image and various information, and a finder eyepiece window 13 are provided. On the upper surface of the camera body 10, a release button 14, a liquid crystal display 15 for displaying information, and an accessory shoe 16 for mounting an external flash device or the like are provided.

A posture sensor 31 for detecting the posture of the camera is provided in the camera body 10. The posture sensor 31 inserts a metal-plated sphere into a metal cylinder, for example, and when the sphere moves in the cylinder by gravity, an electrical signal corresponding to the contact position between the sphere and the cylinder inner wall is output. is there. By fixing the cylinder in the camera body 10 at a predetermined angle, the posture of the camera, specifically, the camera is in the horizontal shooting position (hereinafter, horizontal position) or in the vertical shooting position (hereinafter, vertical position). Can be detected. Further, by sequentially monitoring the sensor output, it can be detected that the camera posture has been changed from the horizontal position to the vertical position or vice versa.
Note that the configuration of the attitude sensor 31 is not limited to the above-described configuration, and other configurations may be used as long as the horizontal position and the vertical position can be detected.

  FIG. 3 shows a viewfinder image, 41 shows a photographing screen, and 42 shows an off-screen display area. Eleven focus detection areas 41a to 41k arranged in a two-dimensional manner are set in the screen, and the blacked out area indicates a selection area. The focus detection area is selected by operating the area selector 11 shown in FIG. Each time the area selector 11 is pressed, the selection area is changed one by one in the direction (either up, down, left, or right) corresponding to the operation part.

  FIG. 2 shows a camera control system, and only elements related to the present invention are shown. On the input side of the CPU 51, the attitude sensor 31, the focus detection device 52, a half-press switch SW <b> 1 that is turned on by half-pressing the release button 14, a release switch SW <b> 2 that is turned on by full-pressing the release button 14, A selection switch SW3 that is turned on by the operation of the area selector 11 is connected. A driver 54 for driving the AF motor 53, an exposure control device 55, and a superimpose display device 56 are connected to the output side of the CPU 51.

  The focus detection device 52 can independently detect the focus adjustment states of the eleven focus detection areas described above, and the CPU 51 controls the AF motor 53 based on the detection output of the focus detection device 52. Under the control of the AF motor 53, the focusing optical system of the photographic lens moves in the optical axis direction to perform focus adjustment. In response to an instruction from the CPU 51, the exposure control device 55 drives a photographing operation member such as an aperture or a shutter to perform exposure. The superimpose display device 56 notifies the photographer by illuminating the selected area in the finder screen. For example, the superimpose display device 56 disclosed in Japanese Patent Application Laid-Open No. 2003-107560 by the present applicant is used. .

  In the above configuration, the photographer selects any focus detection area by the area selector 11, determines the composition so that the selected area overlaps the main subject, and presses the release button 14 halfway. As the half-push switch SW1 is turned on, the CPU 51 detects the focus of the selected area as part of the shooting preparation operation, and adjusts the focus of the shooting lens based on the detection information. When the lens is focused on the subject, the lens is held at that position.

  In addition, the CPU 51 sequentially monitors the output of the posture sensor 31 during the half-press operation to determine whether or not the posture of the camera is changed. When the posture change is detected, the CPU 51 selects any focus detection area. The area is shifted to the central area 41f. For example, FIG. 3A shows a case where the camera is half-pressed in the horizontal position. At this time, the rightmost area 41h in the middle stage is the selection area. When the camera is changed to the vertical position in FIG. 3B while being pressed halfway, the CPU 51 changes the selection area to the central area 41f. FIG. 3B shows the vertical position where the grip of the camera is at the top, but the selection area is similarly changed to the center area 41f in the case of the vertical position where the grip is at the bottom (see FIG. 4). The selection area is also changed to the central area 41f even when the half-pressing initial posture is any vertical position and this is changed to the horizontal position. Further, the CPU 51 immediately activates the superimpose display device 56 in accordance with the change of the selection area, notifies the photographer of the new selection area (center area), and adjusts the focus on the selection area.

  The reason why the selection area is changed in accordance with the change in the posture of the camera is that there is a high possibility that the composition changes due to the change in posture and the initial selection area is no longer appropriate as the selection area. The reason why the selection area is changed to the central area 41f is that the central area 41f is a selection area (reference area) in the initial setting of the camera and is used most frequently. In other words, it is highly likely that the photographer will adjust the main subject to the center area after changing the posture. In this case, the main subject can be focused and the image can be quickly taken simply by changing the posture. On the other hand, if the intended area is not the central area 41f, the photographer changes the selection area by operating the area selector 11. However, the area is changed from the central area 41f. For example, the number of operations of the area selector 11 can be reduced and can be changed quickly.

  By the way, some conventional cameras change the exposure control algorithm according to the camera attitude determination result, change the date imprinting position on the film, or change the orientation of the image displayed on the digital still camera. is there. If the control of this embodiment is applied to such a camera, the posture sensor can also be used, so that an increase in cost can be minimized without increasing the number of parts.

FIG. 5 shows a flowchart for realizing the above-described control.
When the half-push switch SW1 is turned on by half-pressing the release button 14, the CPU 51 executes this program. In step S1, the superimpose display device 56 is driven to superimpose the currently selected focus detection area. Display. In step S2, focus detection is performed by the focus detection device 52 to acquire focus adjustment information of the selected area. In step S3, the focus motor 53 is driven based on the focus adjustment information to bring the photographing lens to the in-focus position. .

  Next, the process goes through a loop of steps S4 to S6. In this loop, the output of the posture sensor 31 is monitored to determine whether or not the posture of the camera is changed (step S4), and whether the release switch SW2 and the half-press switch SW1 are on or off is determined (steps S5 and S6). . When the posture change is detected, it is determined in step S7 whether or not the current selection area is the central area 41f, and if it is the central area 41f, the process proceeds to step S5. If it is not the central area 41f, the selected area is changed to the central area in step S8, and the process returns to step S1. If it is determined in step S5 that the release switch SW2 is on, shooting is performed in step S9, and the process ends. If it is determined in step S6 that the half-press switch is off, the process ends.

  Here, when the camera is at an intermediate position (around 45 degrees) between the horizontal position and the vertical position, the posture sensor may output a horizontal position signal or a vertical position signal. The camera posture may be determined based solely on the sensor output. For example, the photographer attempts to change from the horizontal position to the vertical position by rotating the camera to around 45 degrees (at this time, the sensor output is switched), and at that time In some cases, you can rethink and return to the horizontal position. In order to prevent it from being determined that the posture has been changed in such a case, it is determined that the posture has been changed when there is no change in the sensor output while waiting for a predetermined time (for example, several seconds) after switching the sensor output. It is desirable.

  In the flowchart of FIG. 5, when the center area 41f is originally selected, nothing is performed even if the posture is changed, but only the focus adjustment operation may be performed. Further, the change destination of the selection area associated with the posture change is not limited to the central area 41f, but may be an area set by the user in advance through custom setting or the like, for example. In addition, the selection area was changed in response to the posture change at the time of half-press operation, but even after the half-press operation was canceled and before the so-called half-press timer expired, Similar to the above, the selection area may be changed or the focus may be adjusted.

  When the camera is extremely upward or downward, it may not be possible to determine both the horizontal position and the vertical position. In such a case, the central area may be forcibly selected.

-Second Embodiment-
A second embodiment of the present invention will be described.
In the previous embodiment, the change destination of the selection area associated with the camera posture change was the central area. However, in this embodiment, the selection area after the posture change is determined according to the selection area before the posture change. Show.

  When the photographer changes the posture of the camera, the main subject is often placed at substantially the same position on the screen after the posture change as the screen before the posture change. For example, when the main subject is initially placed in the horizontal position and the main subject is placed at the left edge of the screen and a specific object is placed as the background on the right side of the main subject, the positional relationship between the main subject and the background object in the screen even if this is changed to the vertical position You may want to keep In consideration of this point, in the present embodiment, when a posture change is detected, the focus detection area that is closest to the positional relationship on the screen of the selection area before the posture change is set as a new selection area. FIGS. 6 (a) and 6 (b) show an example. In the horizontal position, the area 41d at the left end of the center stage is the selection area, so in response to the posture change to the vertical position (grip is up). The area 41b at the left end of the center stage in the vertical position screen is set as a new selection area.

When the grip is changed to the lower vertical position in the same case, the selection area is changed to the area 41j as shown in FIG. This area 41j is also the area at the left end of the center stage in the new screen. Furthermore, when returning from the vertical position to the horizontal position, the area 41d becomes the selection area again. Also in the present embodiment, the focus adjustment is started in response to the change of the selection area due to the posture change. According to this, when the main subject is arranged at the same position before and after the posture change, it is possible to quickly focus on the main subject after the posture change. Even if the selected area after the posture change deviates from the main subject, the deviation is very small, so that a desired area can be quickly selected by manual operation.
Such control can be realized by changing step S8 in FIG. 5 to step S80 in FIG.

  FIG. 9 shows an example in which more focus detection areas 101 (black circles are selected areas) are arranged, and the focus detection areas are positioned at equiangular intervals on a plurality of concentric ellipses. Also in this case, in response to the change of the camera posture, the focus detection area having the closest positional relationship to the positional relationship on the screen of the selection area before the posture change is set as a new selection area. Further, in this example, it is also possible to perform control such that the selected area is shifted one by one on the same ellipse by detecting the rotation angle around the optical axis of the camera more finely.

  Convenience by providing the same camera with the algorithm of the second embodiment described above and the algorithm of the first embodiment described above so that any algorithm can be selected by custom setting or the like. Can be improved.

  Further, the case where the photographer manually selects the area in advance has been described above. However, the camera has a mode for automatically selecting an area based on the focus detection result of each focus detection area. The invention can be applied. For example, if the algorithm is to focus on the closest subject among the subjects at multiple area positions (the area where the closest subject exists is the selected area), the algorithm responds to the half-press operation. If area selection and focus adjustment are performed, and then the posture is changed, area selection and focus adjustment can be performed again using the same algorithm. According to this, even if the position of the closest subject changes due to the posture change, it is possible to immediately focus on the main subject.

  The subject to be focused on is not limited to the closest distance. Moreover, the area selection algorithm by half-press operation and the area selection algorithm accompanying posture change may not be the same. For example, in a camera having an algorithm for a horizontal position and an algorithm for a vertical position, area selection may be performed using an algorithm according to the camera posture when half-pressed and when the posture is changed.

  In the first and second embodiments, after performing area selection in response to a posture change, focus adjustment is started in a new selection area. However, focus adjustment is not performed only by area selection. May be. In this case, the photographer recognizes the selected area after the change by superimpose display. If it is appropriate, the focus detection is started by half-pressing and shooting as it is. If it is not appropriate, the selected area is quickly changed by manual operation. it can.

-Third embodiment-
A third embodiment of the present invention will be described.
In the above description, the selected area is changed in response to the change in the camera posture. However, the focus adjustment may be simply started without changing the area. This is realized by, for example, the flowchart of FIG. Also in this case, since focus adjustment is automatically performed only by changing the posture, it is easy to use and shooting can be performed quickly. Since the selection area is not changed, the present invention can be applied to a camera having only one focus detection area.

  In the first to third embodiments, the orientation of the camera is the horizontal position or the vertical position, that is, the rotational attitude around the optical axis of the lens. For example, the inclination (pitch angle) of the optical axis with respect to the horizontal has changed. In this case, it may be determined that the posture has been changed, and the above processing may be performed.

The perspective view of the camera in the embodiment of the present invention. The block diagram which shows the control system of a camera. It is a figure showing change of a selection area when a posture is changed from a horizontal position to a vertical position, and shows a first embodiment in which the selection area is changed to a central area. It is a figure similar to FIG. 3, and shows an example in which the posture is changed to the opposite vertical position. The flowchart which shows the control content of 1st Embodiment. FIG. 6 is a diagram similar to FIG. 3, showing a second embodiment in which the selected area is changed to an area having the same positional relationship as the screen before the posture change. FIG. 6 is a diagram similar to FIG. 6, showing an example in which the posture is changed to the opposite vertical position. The flowchart which shows a part of control content of 2nd Embodiment. The figure explaining the other example of 2nd Embodiment. The flowchart which shows the control content of 3rd Embodiment.

Explanation of symbols

11 Area selector 31 Attitude sensor 41 Shooting screen in viewfinder 41a to 41k, 101 Focus detection area 51 CPU
53 Focus motor SW1 Half-press switch SW2 Release switch SW3 Switch linked to the area selector

Claims (7)

Focusing operation means for performing operations related to autofocus,
Posture detection means for detecting the posture of the camera;
Detecting means for detecting that the posture of the camera has been changed from the output of the posture detecting means;
An autofocus camera characterized in that the focusing operation means is activated in response to detection of a change in posture of the camera.   The focusing operation means includes area selection means for selecting an area to be focused from a plurality of focus detection areas in the photographing screen, and the area selection means includes a focus detection area other than a predetermined reference area. 2. The autofocus camera according to claim 1, wherein when the posture change is detected while the button is selected, the selected area is changed to the reference area in response to the detection. 3.   The autofocus camera according to claim 2, wherein the reference area is an area in the center of the screen.   The focusing operation means includes area selection means for selecting an area to be focused from a plurality of focus detection areas in the shooting screen, and the area selection means responds to the detection of the posture change and changes the posture. 2. The autofocus camera according to claim 1, wherein a focus detection area having a positional relationship closest to the positional relationship on the screen of the previous selection area is set as a new selection area.   The focusing operation unit further includes a focus adjustment unit that performs lens focus adjustment based on a focus adjustment state of the selected area by the area selection unit, and the focus adjustment unit responds to the detection of the posture change, and the area The autofocus camera according to any one of claims 2 to 4, wherein the selection means starts focus adjustment for a newly selected selection area.   The focusing operation means includes a focus adjustment means for adjusting the focus of the lens based on the focus adjustment state of the focus detection area in the shooting screen, and the focus adjustment means starts the focus adjustment in response to a predetermined operation. 2. The autofocus camera according to claim 1, wherein when the posture change is detected thereafter, new focus adjustment is started in response to the detection.   The autofocus camera according to claim 6, wherein the focus adjustment performed in response to the predetermined operation and the focus adjustment performed in response to the posture change are performed on the same focus detection area. .

Images