JP2011186020A - Imaging apparatus including automatic focusing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problems: in order to successively and repeatedly perform an operation for selecting a range-finding point and starting operation for automatic focusing by a photographer, it is necessary to properly use different operation systems many times while performing a series of operations. <P>SOLUTION: An imaging apparatus is equipped with a control means which is configured, in response to the operation of an operation instruction unit: to give the instructions to start the display of the range-finding points currently set by the operation of a range-finding point display part; also to start the operation of the automatic focusing mechanism; and to start to select the range-finding points, and which is configured, in response to the operation of a range-finding point selection part; to stop the operation of the automatic focusing mechanism; to select the optional range-finding points among the plurality of range-finding points; and to display the optional range-finding points newly selected by the operation of the range-finding point display part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image pickup apparatus and an automatic focus adjustment (autofocus) mechanism mounted on the image pickup apparatus, and more particularly to a distance measurement point selection operation in an automatic focus adjustment mechanism capable of multipoint distance measurement.

  In recent imaging apparatuses, in particular, single-lens reflex cameras, an automatic focus adjustment mechanism is an essential equipment. In addition, the automatic focus adjustment mechanism generally has a plurality of distance measuring points (focus detection points). The camera automatically selects a distance measuring point and performs distance measurement. An automatic focus adjustment mechanism having an arbitrary selection mode for selecting and setting a distance measuring point from a plurality of distance measuring points is known.

  Here, the selection of a distance measuring point in the automatic focus adjustment mechanism will be described first, and then the operation of the automatic focus adjustment mechanism will be described.

  As a method for the photographer to select and set the AF point from multiple AF points, and to change the set AF point, while holding down the AF point selection button, dial, cursor button, joystick, etc. A general method is to select a desired distance measuring point position by operating and determine a distance measuring point by releasing a distance measuring point selection button. When the AF point selection button is pressed, the AF point selection mode is called up, and changes to the AF point change by dialing etc. are accepted, and the AF point selection mode ends when the release button is pressed halfway, etc. There is also. During the distance measuring point selection operation, the selected distance measuring point is indicated by a superimpose display described later.

  A display in the finder is generally used as a method for informing the photographer of the set distance measuring point and in-focus state. When ranging point selection is set or when focusing is performed by ranging operation, the ranging frame on the SI board corresponding to the ranging point is illuminated by the LED, and the superimposed display is performed. In recent years, a transmissive LCD has been incorporated into a finder optical system, and there is also a liquid crystal display of a distance measuring frame corresponding to a distance measuring point. The focus status is displayed using an icon (focusing lamp) that emits light in the viewfinder. It is “off” during distance measurement, “lit” when in focus during distance measurement, and “flashing” when out of focus. The display is changed as follows. In addition to being displayed on the LCD installed outside the shooting area in the finder, an icon can be displayed in the shooting area in an electronic view finder in which a color liquid crystal is used for finder display in recent years.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for performing display corresponding to a distance measuring point on an LCD in a finder in order to indicate a focused distance measuring point without using a superimpose display.

  Next, the operation of the automatic focus adjustment mechanism will be described. The automatic focus adjustment mechanism is generally started by a half-press operation (first release) of a release button. In addition to the half-press operation of the release button, there are buttons that can be set with any function assigned to the operation of the auto focus adjustment mechanism, and buttons dedicated to the operation of the auto focus adjustment mechanism. There are also things.

  The automatic focus adjustment mechanism receives the luminous flux of the subject guided by the mirror or the prism by the phase difference automatic focus adjustment sensor, and calculates the defocus amount from the signal value output from the line sensor corresponding to the distance measuring point. The amount of movement of the focus lens is calculated from the calculated defocus amount and lens-specific information such as the focal length, and focusing is performed by moving the focus lens. The above is a general type of phase difference detection type automatic focus adjustment mechanism in a single-lens reflex camera. In recent years, contrast detection type automatic focus adjustment mechanisms are also frequently used mainly in compact digital cameras. The contrast detection method automatic focus adjustment mechanism is a method in which the focus lens is sequentially captured by the image pickup device while the focus lens is driven, and the focus lens position at which the contrast peak is detected is detected. In addition, there are various automatic focus adjustment mechanisms such as an active system that performs distance measurement by irradiating light rays and detecting reflected light.

Japanese Patent No. 3890098

  As described above, the selection of the distance measuring point and the operation of the automatic focus adjustment mechanism are independent and separate functions in a general single-lens reflex camera, and the operation system is different. However, in general, the selection of the distance measuring point and the operation of the automatic focusing mechanism (and the focusing operation including manual focusing) are performed sequentially or simultaneously and are closely related.

  From the viewpoint of the photographer, in order to select a distance measuring point, it must be in focus to some extent, and a focus adjustment operation must be performed. If it is desired to change the distance measuring point after the focus is obtained to some extent, the distance measuring point is changed and selected again and the focus adjustment operation is performed. That is, in order for the photographer to sequentially and repeatedly select the distance measuring point and start the automatic focus adjustment operation, it is necessary to use different operation systems many times during the series of operations. This is not only unfavorable from the viewpoint of operability, but is also a factor of reducing the rapid photographing property.

  In addition, installing a plurality of single-function operation systems causes an increase in hardware costs. It is also an obstacle to downsizing the entire device.

  While existing operation systems have these problems, there is also a problem in introducing an entirely new operation system that has never existed before. Although there are some differences between manufacturers in the operation system of an imaging device, particularly a single-lens reflex camera, a certain degree of commonality is achieved. For this reason, it is necessary to consider the convenience of a photographer who is accustomed to the conventional operation system by adopting a configuration that is not significantly different from the operation system and operation method used for normal photography.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide an imaging apparatus that is improved in operability.

  Accordingly, in the image pickup apparatus according to the present invention as set forth in claim 1, a distance measuring point display unit that allows a photographer to visually recognize a plurality of distance measuring points, and automatic focus adjustment for the plurality of distance measuring points. An automatic focus adjustment mechanism that can perform an operation, a distance measurement point selection unit that selects an arbitrary distance measurement point from the plurality of distance measurement points, an operation start of the automatic focus adjustment mechanism, and an operation start of the distance measurement point display unit In addition, in the imaging apparatus having an operation instruction unit for instructing an operation start of the distance measurement point selection unit, the currently set distance measurement point by the operation of the distance measurement point display unit according to the operation of the operation instruction unit Display start, the operation start of the automatic focus adjustment mechanism, and an instruction to start the distance measurement point selection, and the operation of the automatic focus adjustment mechanism according to the operation of the distance measurement point selection unit Stop and any distance measurement at the plurality of distance measurement points And selection of, characterized by comprising a control means for the display of the newly selected the arbitrary distance-measuring point by the operation of the distance measuring point display unit.

  According to the present invention, it is possible to provide an imaging apparatus in which the operation of the automatic focus adjustment mechanism (and the focus adjustment operation including manual focus adjustment) and the selection of the distance measuring point can be sequentially performed by one operation system. .

  The preferred embodiments of the present invention will be described below with reference to the drawings.

<About the imaging apparatus in the embodiment>
First, an external operation system of the imaging apparatus according to the embodiment of the present invention will be described with reference to the rear perspective view of FIG. In FIG. 1, the first release button that can instruct the start of the operation of the automatic focus adjustment mechanism and the second release button that can instruct the start of the exposure operation are the release buttons 1 that can be pushed in two stages. It is configured on the front.

  In addition, a dial 2 and a cursor key 3 are provided on the upper surface or the rear surface of the imaging apparatus as a distance measuring point selection unit used when the photographer selects an arbitrary distance measuring point from a plurality of distance measuring points. An interface such as a joystick may be used as the distance measuring point selection unit. Further, a ranging point selection unit that can be selected by touching the liquid crystal screen 4 provided in the imaging apparatus may be used.

  Further, an A button 5 is provided on the rear surface of the imaging apparatus main body as an operation instruction unit for instructing an operation start of the automatic focus adjustment mechanism, an operation start of the distance measurement point display unit, and an operation start of the distance measurement point selection unit. The A button 5 is normally arranged so that the photographer can operate with the right thumb, but can be moved as appropriate. If attention is paid to the duplication of functions, the functions can be integrated into the first release button of the release button 1.

  Next, a distance measurement point display section that is referred to when the photographer selects an arbitrary distance measurement point from a plurality of distance measurement points will be described. The distance measuring point display unit illuminates a distance measuring point selected when selecting an arbitrary distance measuring point from a plurality of distance measuring points in the display on the liquid crystal screen 4 in FIG. 1 or the finder image in the finder 6. indicate.

  The liquid crystal screen 4 can be used in a so-called live view shooting, which is a shooting method in which a plurality of distance measuring points are superimposed and displayed while displaying a subject image. FIG. 2 shows an example of display on the liquid crystal screen 4 in live view shooting. FIG. 2 shows a situation in which a cylindrical subject 1, subject 2, and subject 3 arranged obliquely from the front are photographed. At this time, the distance measuring points are the five distance measuring points (left distance measuring point 7, upper distance measuring point 8, center distance measuring point 9, lower distance measuring point 10, right side Among the distance measuring points 11), the left distance measuring point 7 is selected. The selected distance measuring frame is highlighted as if illuminated in the finder, or may be recognized by changing the color.

  Outside the shooting range in the liquid crystal display, there is a finder liquid crystal screen 12 showing various settings of the imaging device. In the vicinity thereof, there is a focusing lamp 13 for displaying the above-mentioned focusing state.

  Even if it is not so-called live view shooting, there is a method of displaying to the photographer by using a menu that schematically displays the arrangement of distance measuring points. FIG. 3 shows a screen display when various functions are set in a single-lens reflex camera shown as an example of an imaging apparatus. A symbol corresponding to the distance measuring point is shown in the center of the screen, and the selected distance measuring point is highlighted as if it is illuminated in the viewfinder. Of course, it may be recognized by changing the color.

  As a most general example, an example of display in the optical viewfinder is shown. Similar to the screen display in the live view shooting using the liquid crystal screen 4, the distance measuring frame on the SI board corresponding to the distance measuring point is illuminated by the LED, and the superimposed display is performed. In recent years, a transmissive LCD has been incorporated into a finder optical system, and there is also a liquid crystal display of a distance measuring frame corresponding to a distance measuring point. A situation is shown in which a cylindrical subject 1, subject 2, and subject 3 arranged obliquely from the front are photographed. At this time, the distance measuring point on the left side is selected from among the five distance measuring points indicated by the brackets. The selected ranging frame is illuminated in the viewfinder. It is to be noted that the electronic view fan inda that has recently appeared can operate in the same manner.

<Operation of Imaging Device in Embodiment>
Next, the operation of the camera in one embodiment of the present invention will be described using the flowcharts shown in FIGS. FIG. 4 shows a series of operations from activation to imaging by the CPU in the camera body. When power is supplied to the camera, this flow starts. In step # 1, initial settings are first made. If there is information such as the set shooting mode, ISO sensitivity, manually set shutter speed, aperture value, etc. Reading those shooting conditions.

  Next, a series of operations of focus detection point display, automatic focus adjustment mechanism operation, and focus detection point selection operation is performed by a subroutine (step # 3). This operation will be described later with reference to FIG.

  In step # 5, it is determined whether or not the first release is pressed. If the first release is pressed as a result of the determination, photometry is performed (step # 7), and automatic focus adjustment distance measurement calculation is performed (step # 9). If the result of determination is that the first release has not been pressed, processing returns to the subroutine (step # 3).

  In step # 11, it is determined whether or not it is in focus. If the result of determination is in focus, focus display is performed (step # 13). If the result of determination is that the lens is not in focus, the lens is driven to the target position calculated in step # 9 (step # 19), and it is determined again whether it is in focus (step # 21). If the result of determination is in focus, focus display is performed (step # 13). If the result of determination is not in focus, out-of-focus display is performed (step # 23). After performing out-of-focus display in step # 23, it is determined whether or not release priority is set (step # 25). As a result of the determination, if release priority is set, the process proceeds to step # 15. If the result of determination is that release priority is not set, the process returns to the subroutine (step # 3).

  After performing in-focus display in step # 13 or out-of-focus display in step # 23, it is determined in step # 15 whether the second release is being pressed. If the second release is pressed as a result of the determination, an exposure operation is performed (step # 17). If the result of determination is that the second release has not been pressed, processing returns to the subroutine (step # 3).

  Here, the above-described exposure operation will be described. The exposure operation refers to an operation performed by full pressing in a general still camera. More specifically, mirror driving in a single-lens reflex camera and shutter driving (including a focal plane method, an electronic shutter method, and a lens shutter method) are performed. The digital still camera includes reading of image data output from the image sensor, image processing, and image storage.

  Next, a subroutine (step # 3) for performing a series of operations of ranging point display, operation of the automatic focusing mechanism, and ranging point selection operation will be described.

  When this subroutine is entered, it is first determined in step # 27 whether the A button has been pressed. If the result of determination is that the A button has been pressed, the currently set focus point is displayed (step # 33). If the result of determination is that the A button has not been pressed, the distance measuring point changing flag is cleared (0) in step # 29 and the routine returns.

  After the distance measuring point is displayed in step # 33, it is determined in step # 35 whether the distance measuring point changing flag is 1. As a result of the determination, if the ranging point changing flag is 1, the process proceeds to step # 49. If the result of determination is that the ranging point changing flag is not 1, automatic focus adjustment ranging calculation is performed (step # 37), and in step # 39, it is determined whether or not it is in focus. If the result of determination is in focus, focus display is performed (step # 45). If the result of determination is that the lens is not in focus, the lens is driven to the target position calculated in step # 37 (step # 41), and it is determined again whether the lens is in focus (step # 43). If the result of determination is in focus, focus display is performed (step # 45). If the result of determination is not in focus, out-of-focus display is performed (step # 47).

  After performing in-focus display in step # 45 or non-focus display in step # 47, it is determined in step # 49 whether the dial is operated clockwise. If the result of determination is that the dial has been operated clockwise, the focus lens drive is stopped (step # 51), and the currently set focus point is changed to the right focus point (step # 53). In step # 61, the ranging point changing flag is set (1), and the process returns to the original routine.

  If the result of determination in step # 49 is that the dial has not been operated clockwise, it is determined in step # 55 whether the dial has been operated counterclockwise. If the result of determination is that the dial has been operated counterclockwise, driving of the focus lens is stopped (step # 57), and the currently set focus point is changed to the left focus point (step # 59). In step # 61, the ranging point changing flag is set (1), and the process returns to the original routine.

  In the present embodiment, the example using the dial as the distance measuring point selection unit has been described in detail, but it can be replaced by other operation methods as described above.

<Example of actual operation>
The operation of the present invention shown in claim 1 can be expressed more simply. When the A button provided on the camera is pressed, the camera displays the currently set distance measurement frame, and then the operation of the automatic focus adjustment mechanism. Is started, and the state further shifts to a state of accepting an instruction to change the distance measurement frame. Here, when the photographer wants to change the distance measuring frame, after pressing the A button, the operation of the distance measuring point selection unit such as a dial stops the operation of the automatic focusing mechanism, and the measurement is performed. A distance measuring point corresponding to the operation of the distance point selecting unit is selected. As long as the operation of the distance measuring point selection unit continues, the movement and display of the distance measuring point are repeated. When the photographer finishes changing the ranging point and presses the A button again, the camera displays the currently set ranging point and then starts the operation of the automatic focus adjustment mechanism.

  Here, the relationship between the actual operation example and the above-described flowcharts of a series of operations of the focus detection point display, the auto focus adjustment mechanism, and the focus detection point selection operation will be described with reference to FIGS. .

  FIG. 6 shows a state in which the subject is observed from the viewfinder of the single-lens reflex camera. At this time, in FIG. 4, the initial setting in step # 1 is completed. In the subroutine of FIG. 5, step # 27, step # 29, and step # 5 of the main routine are looped. At this time, the focus lamp 13 is not lit because it is not in focus.

  Here, when the A button 5 is pressed, the process proceeds from step # 27 to step # 33 in the subroutine of FIG. 5, and the currently set distance measuring point is displayed. Here, as shown in FIG. 7, the left distance measuring point 7 is first selected and illuminated in the viewfinder.

  Subsequently, the process proceeds to step # 35. However, since the ranging point changing flag is not set to 1, the process proceeds to step # 37, and the automatic focus adjustment mechanism performs a ranging calculation. In step # 39, the in-focus state is determined. At this time, since the in-focus state is not reached, the process proceeds to step # 41, and the lens is driven to the lens target position calculated in step # 37.

  FIG. 8 shows a state where the focus lens is driven in step # 41 and the in-focus state is reached. When the focus determination in step # 43, the process proceeds to step # 45, and the focus lamp 13 is turned on.

  FIG. 9 shows a state where the photographer has operated the dial, which is a distance measuring point selection unit, to rotate clockwise from the state of FIG. Although the focus lens has already stopped driving, the focus lens drive stop process is performed in step # 51, and the center distance measuring point 9 which is the distance measuring point set right in step # 53 is the right one. Changed to In step # 61, the ranging point changing flag is set to 1, and the process returns to the main routine.

Here, it is assumed that the first release is not pressed and the A button is further pressed. In the flowcharts of FIGS. 4 and 5, since the first release is not pressed and the A button is pressed, the process proceeds from step # 5 to step # 27 of the subroutine, and then proceeds to step # 33. In step # 33, the center distance measuring point 9 after the change is displayed. Further, in step # 35, since the ranging point changing flag is set to 1 in step # 61, the process proceeds to step # 49.
If the dial operation and the first release operation are not performed here, the process returns to the main routine via step # 49 and step # 55.

  Subsequently, if the first release and the A button are not pressed, the process proceeds to step # 29 via step # 27, the ranging point changing flag is cleared (0), and the process returns to the main routine.

  Here, when the first release is not operated and the A button 5 is pressed, the process proceeds from step # 27 to step # 33 in the subroutine of FIG. 5, and the currently set distance measuring point is displayed. Here, as shown in FIG. 9, the center distance measuring point 9 which is the changed distance measuring point is illuminated in the finder.

  Subsequently, the process proceeds to step # 35, but since the ranging point changing flag is cleared in step # 29, the process proceeds to step # 37, and the automatic focus adjustment mechanism performs a ranging calculation. In step # 39, the in-focus state is determined. At this time, since the in-focus state is not reached, the process proceeds to step # 41, and the lens is driven to the lens target position calculated in step # 37.

  FIG. 10 shows a state in which the focus lens is driven in step # 41 and the in-focus state is reached. When the focus determination in step # 43, the process proceeds to step # 45, and the focus lamp 13 is turned on.

  Thereafter, if the dial operation is not performed, the focus detection point changing flag is not set and the process returns to the main routine.

  In the above embodiment, the camera (imaging device) is taken as an example. However, since the present invention can be easily added as long as it has an automatic focus adjustment mechanism, the applicable imaging device is limited to this type of camera. Absent. For example, it can also be deployed in digital video cameras, surveillance cameras, web cameras, mobile phones and the like.

It is a back perspective view showing a single-lens reflex camera in an example of the present invention. It is an example of the display of the liquid crystal screen of the single-lens reflex camera in the Example of this invention. 4 is a screen display for setting various functions of the single-lens reflex camera according to the embodiment of the present invention. It is a flowchart (main routine) in the Example of this invention. It is a flowchart (subroutine) in the Example of this invention. It is a finder display of the single-lens reflex camera in the Example of the present invention. It is a finder display of the single-lens reflex camera in the Example of the present invention. It is a finder display of the single-lens reflex camera in the Example of the present invention. It is a finder display of the single-lens reflex camera in the Example of the present invention. It is a finder display of the single-lens reflex camera in the Example of the present invention.

1 Release button 2 Dial 3 Cursor button 4 LCD screen 5 A button 6 Finder 7 Left focus point 8 Upper focus point 9 Center focus point 10 Lower focus point 11 Right focus point 12 Finder LCD Screen 13 Focus lamp

Claims (1)

A distance measuring point display unit that allows a photographer to visually recognize a plurality of distance measuring points; an automatic focus adjustment mechanism that can perform automatic focus adjustment on the plurality of distance measuring points; A distance measuring point selection unit for selecting an arbitrary distance measuring point from the distance measuring points, and an operation instruction for instructing an operation start of the automatic focus adjustment mechanism, an operation start of the distance measuring point display unit, and an operation start of the distance measuring point selection unit In an imaging device having a unit,
In response to the operation of the operation instruction unit, display of the currently set ranging point by operation of the ranging point display unit, start of operation of the automatic focus adjustment mechanism, and selection of a ranging point are started. Instructions to do so,
In response to the operation of the ranging point selection unit, the operation of the automatic focusing mechanism is stopped, the selection of an arbitrary ranging point among the plurality of ranging points, and the operation of the ranging point display unit An imaging apparatus comprising: control means for displaying the selected arbitrary distance measuring point.

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