JP2007279677A - Focus state display device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a focus state display device capable of easily and accurately performing focusing by MF in a camera for performing mount climbing AF and capable of performing MF. <P>SOLUTION: The focus state display device for the camera is provided with: an imaging part 1; a focusing evaluation value calculation part 2 for calculating a focusing evaluation value for evaluating a degree of focusing of an object image at present time on the basis of an image signal outputted from the imaging part 1; a peak detection part 3 for detecting that the focusing evaluation value passes a peak value by referring to the focusing evaluation value outputted from the focusing evaluation value calculation part 2; a focusing meter preparation part 5 for preparing a focusing meter image for visually expressing the focusing evaluation value; a meter format control part 4 for generating a signal instructing a display format or the like of a display bar or the like prepared by the focusing meter preparation part 5 and outputting the generated signal to the focusing meter preparation part 5; and a display part 6 for composing an image and outputting the composed image to a monitor 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a focus state display device for a camera capable of manual focus, and more particularly to a camera focus state display device capable of displaying a focus level.

  In general, in manual focus (hereinafter referred to as MF) in a digital camera, a user observes a subject with a viewfinder or an electronic viewfinder (EVF) while manually rotating a photographing lens, and is considered to have the best focus. A method of stopping the movement of the photographing lens at the lens position is performed.

  However, in the MF as described above, it cannot be said that the lens position at which the user stopped the photographing lens is the lens position at which the best focusing state can be obtained due to factors such as the user's ability and the viewability of the viewfinder.

  On the other hand, as autofocus (hereinafter referred to as AF) of a digital camera, an evaluation value (hereinafter referred to as a focus evaluation value) representing the degree of focus is calculated by performing a predetermined calculation on the output of the image sensor, There is known a method for obtaining the best in-focus state by moving the photographing lens to the lens position of the photographing lens when the focus evaluation value becomes a peak value. The focus evaluation value indicates the magnitude of the high frequency component of the video signal, and indicates a higher value as the focus state is reached. Therefore, it is possible to detect the lens position where the best focus state can be obtained by scanning the lens position where the focus evaluation value becomes the peak value. This AF method is called the name of mountain climbing AF, imager AF, or contrast AF.

  By the way, as a technique for using the focus evaluation value for focusing in MF, for example, the following techniques are known.

  First, Patent Document 1 discloses a camera device that performs real-time display of a focused state level. Patent Document 2 discloses an electronic camera that displays information on the position of a photographing lens and displays information on a focus evaluation value in a bar.

As described above, according to the techniques disclosed in Patent Documents 1 and 2, an MF that is relatively more accurate than a commonly performed MF is realized.
JP-A-6-113184 JP 2001-42207 A

  However, in the techniques disclosed in Patent Documents 1 and 2, since the focus evaluation value is simply presented to the user who performs MF, the accuracy and operability of focusing by MF are improved. I can't say that.

  Therefore, for example, what is obtained by the MF of the camera, for example, that the photographic lens of the camera is easily and accurately moved to the position of the photographic lens when the focus evaluation value reaches the peak value is realized. Is hard to say.

  The present invention has been made in view of the above-described circumstances, and is a camera that performs hill-climbing AF, and in a camera capable of MF, a focus state display that allows easy and accurate focusing with MF. An object is to provide an apparatus.

  To achieve the above object, a focus state display device for a camera according to a first aspect of the present invention forms a subject image via a photographing lens capable of manual focusing by a photographer, and the photographing lens. Imaging means for converting the subject image into a video signal, focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at predetermined time intervals based on an output of the imaging means, and the photographer While the focus of the photographic lens is being focused by manual focus, the evaluation value display means for displaying the calculation result of the focus evaluation value calculation means, and the focus of the photographic lens by manual focus by the photographer In the meantime, the maximum value of the focus evaluation value is calculated based on the output of the focus evaluation value calculating means, and the level of the maximum value is Characterized by comprising a maximum value displaying means for displaying together with the display by the value display means.

  In order to achieve the above object, a camera focus state display device according to a second aspect of the present invention forms a subject image via a photographing lens capable of manual focus by a photographer, and the photographing lens, and Imaging means for converting the subject image into a video signal, focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at predetermined time intervals based on an output of the imaging means, and the photographer While the focus of the photographic lens is being focused by manual focus, the evaluation value display means for displaying the calculation result of the focus evaluation value calculation means, and the focus of the photographic lens by manual focus by the photographer The maximum focus evaluation value is calculated based on the output of the focus evaluation value calculation means while the latest focus evaluation is being performed. The maximum value coincidence determining means for determining whether or not the maximum value coincides again with the maximum value after the value has decreased by a predetermined value or more from the maximum value, and the maximum value coincidence determining means, the focus evaluation value is again And a maximum value coincidence notifying unit for notifying the photographer of the fact when it is determined that the maximum value is met.

  In order to achieve the above object, a focus state display device for a camera according to a third aspect of the present invention forms a subject image via a photographing lens capable of manual focusing by a photographer, and the photographing lens. Imaging means for converting the subject image into a video signal, focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at predetermined time intervals based on an output of the imaging means, and the photographer While the focus of the photographic lens is being focused by manual focus, the evaluation value display means for displaying the calculation result of the focus evaluation value calculation means, and the focus of the photographic lens by manual focus by the photographer In the meantime, the maximum value of the focus evaluation value is calculated based on the output of the focus evaluation value calculating means, and the level of the maximum value is The focus evaluation value based on the output of the focus evaluation value calculation means while the maximum value display means is displayed together with the display by the value display means, and the photographing lens is focused by manual focus by the photographer. A maximum value coincidence determining means for determining whether or not the latest focus evaluation value is a value that is lower than the maximum value by a predetermined value or more and then again coincides with the maximum value; And a maximum value coincidence notifying unit for notifying the photographer of the fact that the maximum value coincidence determining unit determines that the focus evaluation value again matches the maximum value. .

In order to achieve the above object, a focus state display device for a camera according to a fourth aspect of the present invention forms a subject image via a photographing lens capable of manual focus by a photographer, and the photographing lens. Imaging means for converting the subject image into a video signal, focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at predetermined time intervals based on an output of the imaging means, and the photographer While the focus of the photographic lens is being focused by manual focus, the evaluation value display means for displaying the calculation result of the focus evaluation value calculation means, and a substantially entire image corresponding to the video signal are displayed as a through image. To switch to the non-enlarging mode, which is the display mode, or the enlarging mode, which is the mode for enlarging a part of the image corresponding to the video signal and displaying the through image And the focus evaluation value calculation means includes a focus evaluation value calculation area, which is a target area for performing focus evaluation value calculation in an image corresponding to the video signal, in the non-enlarging mode. The area is set differently in the enlargement mode.

  The present invention can provide a focus state display device that can easily and accurately focus on MF in a camera that performs hill-climbing AF and that can perform MF.

[First Embodiment]
Hereinafter, a camera focus state display device according to a first embodiment of the present invention will be described with reference to the drawings, taking a camera having a so-called hill-climbing AF function as an example.

  First, the main configuration of the camera focus state display device according to the first embodiment will be described with reference to the block diagram shown in FIG. Details of the operation control will be described later with reference to other drawings.

  Reference numeral 1 indicates that a subject image is formed through a photographing lens of a camera on which the camera focus state display device according to the first embodiment is mounted, and the formed subject image is displayed. It is an image pickup unit for converting into a video signal by photoelectric conversion. And this imaging part 1 outputs the said video signal to the focus evaluation value calculating part 2 mentioned later.

  The focus evaluation value calculation unit 2 calculates a focus evaluation value for evaluating the degree of focus of the subject image at the current time point based on the video signal output from the imaging unit 1.

  The peak detection unit 3 refers to the focus evaluation value output from the focus evaluation value calculation unit 2, and detects that the focus evaluation value has passed the peak value during the change process. It is. That is, the peak detection unit 3 indicates that the focus evaluation value has passed the peak value in the process of changing the focus evaluation value due to the driving (focusing operation) of the photographing lens performed by the user of the camera. Is detected.

  Here, the focus meter creation unit 5 creates a focus meter image that visually represents the focus evaluation value based on the focus evaluation value output from the focus evaluation value calculation unit 2. . The focus meter image represents the AF focus evaluation value in a graphic shape, and has a display graphic such as a display bar inside. The details of the focusing meter image will be described later with a specific example. The focus meter creation unit 5 changes the display scale of the focus meter image according to a signal indicating that the focus evaluation value output from the peak detection unit 3 has passed the peak value. The display scale will be described later in detail.

  Further, the meter form control unit 4, based on the information on the peak detection of the focus evaluation value output from the peak detection unit 3, the display bar and the like in the focus meter created by the focus meter creation unit 5 And a signal instructing the presence or absence of a peak hold display, which will be described later, is generated and output to the focusing meter creating unit 5.

  Then, the display unit 6 synthesizes the video signal output from the imaging unit 1 and the focus meter image output from the focus meter creation unit 5, and creates an image created by the synthesis, for example, It outputs to the monitor 7 which consists of LCD etc. That is, the monitor 7 is a member for displaying an image generated by the display unit 6.

  FIG. 2 is a block diagram showing in detail the configuration of a camera equipped with the camera focus state display device according to the first embodiment. In the following, with reference to the figure, the components of the camera will be described in detail by taking AF performed by a normal camera as an example.

  The correspondence between the constituent members of the focus state display device shown in the block diagram of FIG. 1 and the constituent members of the camera shown in the block diagram of FIG. 2 is as follows. That is, the function of the imaging unit 1 is performed by the imaging optical system 102, the diaphragm 104, the shutter unit 208, the imaging element 212, and the imaging interface circuit 217 shown in FIG. The function by the focus evaluation value calculation unit 2, the function by the peak detection unit 3, the function by the meter form control unit 4, the function by the focus meter creation unit 5, and the function by the display unit 6 are, for example, It is carried by the image processing controller 218 and the buffer memory 219 shown in FIG. The function of the monitor 7 is performed by, for example, a liquid crystal monitor 222 shown in FIG.

  The imaging unit 1, the focus evaluation value calculation unit 2, the peak detection unit 3, the focus meter creation unit 5, and the display unit 6 are controlled by a body control microcomputer (hereinafter referred to as Bucom) 201 described later. Then, an instruction is issued to the image processing controller 218 and the buffer memory 219 to sequentially execute the processing in each of them.

  First, as shown in FIG. 2, the camera on which the camera focus state display device according to the first embodiment is mounted includes a lens barrel 100 and a camera body 200.

  Here, each part of the lens barrel 100 is controlled by a lens control microcomputer (hereinafter referred to as Lucom) 101. On the other hand, each unit of the camera body 200 is controlled by the Bucom 201. Here, when the lens barrel 100 is attached to the camera body 200, the Lucom 101 and the Bucom 201 are communicably connected via the communication connector 101a. In this case, as a camera system, the Lucom 101 is operated so as to be subordinate to the Bucom 201.

  A photographing optical system 102 is disposed inside the lens barrel 100. Here, in FIG. 2, a plurality of optical lenses (photographing lenses) constituting the photographing optical system 102 are representatively illustrated as one optical lens. The photographing optical system 102 is moved in the optical axis direction by a DC motor (not shown) existing in the lens driving mechanism 103.

  A diaphragm 104 is provided behind the photographing optical system 102. The diaphragm 104 is driven to open and close by a stepping motor (not shown) existing in the diaphragm drive mechanism 105. By controlling the opening and closing of the diaphragm 104, the amount of light flux from the subject incident on the camera body 200 via the photographing optical system 102 is controlled.

  Here, the control of the DC motor in the lens driving mechanism 103 and the control of the stepping motor in the diaphragm driving mechanism 105 are performed by the Lucom 101 that has received a command from the Bucom 201. Further, when the focus ring 106 which is a rotatable member provided on the outer periphery of the lens barrel 100 is rotated by the user, the photographing optical system 102 is driven by the lens driving mechanism 103 in synchronization with the rotation. The That is, the focus ring 106 is a member for manual focus by the user.

  In addition, a finder device including a main mirror 202a, a pentaprism 202c, and an eyepiece 202d is provided inside the camera body 200. When the camera is in a normal state, a part of the light beam from the subject incident through the photographing optical system 102 is reflected by the main mirror 202a. Thereby, an image for observation is formed through the pentaprism 202c and the eyepiece lens 202d.

  Here, a photometric circuit 204 is provided in the vicinity of the pentaprism 202c, and a part of the light beam that has passed through the pentaprism 202c enters a photosensor (not shown) in the photometric circuit 204. In the photometry circuit 204, a well-known photometry process is performed based on the light amount of the light beam detected by the photosensor. The result processed by the photometry circuit 204 is transmitted to the Bucom 201.

  In the Bucom 201, the exposure amount at the time of photographing is calculated based on the result input from the photometry circuit 204. This result is transmitted from Bucom 201 to Lucom 101. In the Lucom 101, drive control of the diaphragm 104 is performed based on the exposure amount notified from the Bucom 201.

  The light beam transmitted through the main mirror 202a and reflected by the sub mirror 203 is guided to an AF sensor unit 205 for performing an automatic focus adjustment process (AF process). An area sensor (not shown) is provided inside the AF sensor unit 205, and a light beam incident on the area sensor is converted into an electric signal.

  The output from the area sensor is transmitted to the Bucom 201 via the AF sensor driving circuit 206. Then, ranging processing is performed in the Bucom 201, and the focus state (defocus amount) of the photographing optical system 102 necessary for focus adjustment is calculated. The calculation result is transmitted from Bucom 201 to Lucom 101. In the Lucom 101, drive control of the photographing optical system 102 is performed based on the movement amount notified from the Bucom 201.

  By the way, when the camera is in the photographing operation state, the main mirror 202a is moved to a predetermined up position where it is retracted from the optical axis of the photographing optical system 102. Such driving of the main mirror 202 a is performed by the mirror driving mechanism 207. The mirror drive mechanism 207 is controlled by the Bucom 201. Here, when the main mirror 202a is moved to the up position, the sub mirror 203 is folded accordingly.

  As the main mirror 202 a is moved to the up position in this way, the light beam from the subject that has passed through the photographing optical system 102 enters the direction of the shutter unit 208. The light beam that has passed through the shutter unit 208 is then incident on the image sensor 212 disposed behind the shutter unit 208. Note that the shutter unit 208 is a focal plane shutter that includes a front curtain and a rear curtain. Here, the spring force for driving the front curtain and the rear curtain is charged by the shutter charge mechanism 209. The front curtain and the rear curtain are driven by the shutter control circuit 210. The shutter charge mechanism 209 and the shutter control circuit 210 are controlled by the Bucom 201.

  The luminous flux of the subject image formed by the image sensor 212 is converted into an electrical signal (video signal). The electrical signal is read out and digitized via the imaging interface circuit 217 at every predetermined timing. Then, the image data obtained by digitization by the imaging interface circuit 217 is stored in a buffer memory 219 constituted by an SDRAM or the like via an image processing controller 218. Here, the buffer memory 219 is a memory for temporarily storing data such as image data, and is used as a work area when various processes are performed on the image data. The buffer memory 219 temporarily stores data related to the processing executed by the focus evaluation value calculation unit 2, the peak detection unit 3, the focus meter creation unit 5, and the display unit 10 in FIG. It is a memory to do.

  Thereafter, the image processing controller 218 reads the image data read out via the imaging interface circuit 217 and stored in the buffer memory 219. Image data read by the image processing controller 218 is subjected to known image processing such as white balance correction, gradation correction, and color correction, and then stored in the buffer memory 219. At the time of image recording, the image data processed by the image processing controller 218 is compressed by a known compression method such as the JPEG method. The JPEG data obtained by the JPEG compression is stored in the buffer memory 219 and then recorded on the FlashRom 220 or the recording medium 221 as a JPEG file to which predetermined header information is added.

  Here, the FlashRom 220 is assumed to be a memory built in the camera, and the recording medium 221 is assumed to be mounted outside the camera. As the recording medium 221, for example, a memory card or a hard disk drive configured to be detachable from the camera is used.

  Further, when an image is played back from the JPEG file recorded on the FlashRom 220 or the recording medium 221, the JPEG data recorded on the FlashRom 220 or the recording medium 221 is read and decompressed by the image processing controller 218. Is done. Thereafter, the decompressed data is converted into a video signal, resized to a predetermined size for display, and output and displayed on the liquid crystal monitor 222.

  The Bucom 201 is connected to a nonvolatile memory 223 that stores predetermined control parameters necessary for camera control. The non-volatile memory 223 is composed of, for example, a rewritable EEPROM. Further, a battery 225 as a power source is connected to the Bucom 201 via a power circuit 224. The voltage of the battery 225 is converted to a voltage required by each part of the camera system by the power supply circuit 224 and supplied to each part of the camera system.

  The Bucom 201 includes an operation display LCD 226 for notifying the user of the operation state of the camera by display output, and a camera operation SW (camera operation switch) 227 for detecting operation states of various operation members of the camera. And are connected.

  By the way, when electronic viewfinder (EVF) display is performed in the camera, the image data read out via the imaging interface circuit 217 and stored in the buffer memory 219 is read out by the image processing controller 218. The image data read by the image processing controller 218 is subjected to image processing such as white balance correction for EVF display, and then stored in the buffer memory 219 separately from the read image data. Thereafter, the image data stored in the buffer memory 219 is read out by the image processing controller 218 in units of frames and converted into video signals. The video signal is resized to a predetermined size for display and then output and displayed on a liquid crystal monitor 222 as display means. The user can check the captured image from the image displayed on the liquid crystal monitor 222.

  If the operation control of EVF display as described above is performed, display generally referred to as a through image can be performed. In order to display a through image, the following operation control is usually performed. That is, first, the main mirror 202a is moved to the up position, and the shutter unit 208 is opened. As a result, the imaging light flux directly enters the image sensor 212. Thereafter, the image data acquired by the image sensor 212 by shooting at a predetermined frame rate (the number of shot images per second) is read by the image processing controller 218 and displayed on the liquid crystal monitor 222. By observing the through image display on the liquid crystal monitor 222, the user can observe the subject image without looking into the eyepiece.

  Hereinafter, various operation members used by the user of the camera will be described with reference to FIG. 3 showing a rear view of the camera equipped with the in-focus state display device according to the first embodiment.

  As shown in the figure, on the back of the camera 11, a main dial 316, an AF frame button 317, an AE lock button 318, a playback mode button 319, a delete button 320, a protect button 321 and an information display button are displayed. 322, a menu button 323, a cross button 324, an OK button 325, and a live button 326 are provided. A mode dial 303 is provided on the upper surface of the camera 11. Hereinafter, each member will be described sequentially.

  First, the main dial 316 is a member for changing the setting of the function related to the operation member currently pressed by the user by being rotated.

  The mode dial 303 is a member for setting various shooting modes. Here, the mode dial 303 will be described by taking a scene mode (SCN) as an example of the various shooting modes. That is, when the main dial 316 is rotated by the user while the mode dial 303 is set to SCN, the liquid crystal monitor 222 displays a menu screen related to setting of shooting conditions according to a desired scene. Is done. Here, examples of the desired scene include portraits, sports, commemorative photography, landscapes, night scenes, and the like. Various shooting conditions such as exposure, flash emission, photometry mode, AF method, and continuous shooting interval are set according to the scene selected by the user.

  The AF frame button 317 is a button for selecting an AF method at the time of shooting. When the main dial 316 is operated while the AF frame button 317 is being pressed, the AF method is changed to, for example, multi AF or spot AF.

  In the multi AF, the focus state of a plurality of ranging points in the screen is detected. On the other hand, in the spot AF, the focus state of one point (can be selected from a plurality of candidates) in the screen is detected.

  The AE lock button 318 is a button for fixing exposure conditions. While the AE lock button 318 is being pressed, the exposure amount calculated at that time is fixed.

  The reproduction mode button 319 is a button for switching the operation mode of the camera 11 to a reproduction mode in which an image can be reproduced and displayed on the liquid crystal monitor 222 from a JPEG file recorded on the FlashRom 220 or the recording medium 221.

  The delete button 320 is a button for deleting the image data (JPEG file) from the FlashRom 220 and the recording medium 221 during the playback mode.

  The protect button 321 is a button for protecting the image data so that the image data is not accidentally erased during the reproduction mode.

  The information display button 322 is a button for causing the liquid crystal monitor 222 to display image information based on additional information (for example, Exif information) of image data.

  The menu button 323 is a button for displaying a menu screen on the liquid crystal monitor 222. This menu screen is composed of menu items having a plurality of hierarchical structures. The user can select a desired menu item with the cross button 324 and can determine the item selected with the OK button 325. Here, the menu items include, for example, a setup menu for the FlashRom 220 and the recording medium 221, a shooting menu capable of setting image data quality, image processing, scene mode, and the like, playback conditions during image playback, and settings during image printing. There are a playback menu that allows the user to perform various operations, a custom menu that allows various fine settings according to the photographer's preference, a setup menu that sets the operating state of the camera such as the type of warning sound, and the like.

  The live button 326 is a button for selecting a mode for displaying the above-described through image. Hereinafter, a mode for displaying a through image is referred to as a live view mode. When the live button 326 is pressed by the user, display of a through image on the liquid crystal monitor 222 is started (entering the live view mode). Thereafter, when the live button 326 is pressed again, the live view mode is exited. During the live view mode, since the main mirror 202a is in the up position, no light beam enters the AF sensor unit 205. That is, in this case, the AF operation is impossible. Therefore, when the live view mode is entered, the Bucom 210 switches from the AF operation state to the MF operation state.

  The contents set by the operation of each operation member by the user are stored in the buffer memory 219 or a memory (not shown) in the Bucom 201.

  Hereinafter, an actual in-focus state display scene by the in-focus state display device according to the first embodiment will be described with reference to FIGS.

  First, as described above, when the user presses the live button 326, the camera enters a live view mode. At this time, the liquid crystal monitor 222 starts displaying a through image of the subject.

  When the camera enters the live view mode, the enlargement box 230 for designating an enlargement area is displayed in the display screen of the liquid crystal monitor 222 as shown in FIG. 4A (in FIG. 4A). Does not depict the subject).

  Here, the enlarged box 230 shown in FIGS. 4A and 4B is a display that can be moved to a user desired area on the liquid crystal monitor 222 as shown in FIG. 4A. Therefore, the user selects the enlargement box 230 so as to overlap the desired area including the image of the portion to be enlarged and displayed. The enlargement box 230 is moved by operating the cross button 324 by the user. In other words, the user operates the cross button 324 to move the enlargement box 230 to a position desired by the user within the display screen of the liquid crystal monitor 222. Thereafter, when the user operates the OK button 325, an enlarged display of the region where the enlargement box 230 is overlaid is performed on the liquid crystal monitor 222 (see FIG. 4C).

  Thus, in the live view mode, the user can enlarge and display an arbitrary area. The purpose of the enlarged display of such an arbitrary area is to make it easier for the user to focus at the time of MF. Hereinafter, a description will be given along a time series.

  Here, as shown in FIGS. 4B and 4C, for example, when an area including the head of the subject 231 is enlarged and displayed, the head of the subject 231 is included by the operation of the cross button 324 by the user. When the enlargement box 230 is aligned with the area and then the OK button 325 is pressed, the head area of the subject 231 is enlarged and displayed on the liquid crystal monitor 222 as shown in FIG. Mode). Hereinafter, the mode for performing the enlarged display as shown in FIG. 4C is referred to as an enlarged mode. In this way, the image (see FIG. 4B) in the area of the enlargement box 230 whose position is set by the user uses the entire display screen of the liquid crystal monitor 222 as shown in FIG. 4C. The enlarged display is made.

  Here, in the enlargement mode, the image of the area in the enlargement box 230 (in this example, the image of the head of the subject 231) is enlarged and displayed on the liquid crystal monitor 222. A 50% area of the entire display screen from the center of the liquid crystal monitor 222 in the vertical and horizontal directions is a focus evaluation value calculation area 232. That is, the focus evaluation value in the focus evaluation value calculation area 232 is calculated every predetermined frame rate.

  The focus evaluation value calculated in the focus evaluation value calculation area 232 is displayed as a display bar 241 in the focus meter 240 on the right side of the display screen on the liquid crystal monitor 222 as shown in FIG. 4C, for example. Is displayed. Here, the longer the length of the display bar 241, the higher the focus evaluation value (the higher the degree of focus), and the shorter the length of the display bar 241, the lower the focus evaluation value (the lower the degree of focus). . Although the focus evaluation value display bar 241 is displayed only in the enlargement mode here, the focus meter 240 and the display bar are similarly displayed in the non-enlargement mode shown in FIG. Of course, 241 may be displayed.

  The calculation for expressing the focus evaluation value as the display bar 241 in the focus meter 240 will be described later.

  Hereinafter, the flow of operation control processing in the Bucom 201 in the shooting operation in the live view mode will be described with reference to the flowchart shown in FIG. Note that the detailed operation control of the constituent members of the camera is as described above with reference to FIG. 2, and therefore, the processing flow will be mainly described here.

  A release switch (not shown) in the camera is a general two-stage switch. That is, the first release switch is turned on by being half pressed by the user, and the second release switch is turned on by being fully pressed. The photographing operation is executed when the second release switch is turned on.

  First, when the transition operation to the live view mode described above is performed (when the user presses the live button 326), the camera enters the live view mode. At this time, the series of processes described above with reference to FIGS. 4A to 4C is performed by a user operation. Since this is not the gist of the present invention, the details are omitted. After the process in the previous stage of the live view mode is performed, the process proceeds to the process of the flowchart illustrated in FIG.

  First, the live view mode operation in the in-focus state display device according to the first embodiment is performed, and display of a through image of the subject is started on the liquid crystal monitor 222 (step S1). Here, step S1 will be described in detail later with reference to another flowchart. When the release button (not shown) is fully pressed by the user during the live view mode operation in step S1, the second release switch is turned on. Thereby, the processing of the live view mode operation in step S1 is completed. Then, the main mirror 202a is driven through the mirror driving mechanism 207 from the up position to the down position (initial position) which is the position of the main mirror 202a shown in FIG. 2 (step S2). This step S2 is a step for executing a photometric operation.

  Next, photometry is performed by the photometry circuit 204, and the aperture time of the shutter unit 208 and the aperture value of the aperture 104 are calculated (step S3). Then, the main mirror 202a is driven to the up position by the mirror driving mechanism 207 (step S4). Further, the diaphragm 104 is driven based on the diaphragm value calculated in step S3 (step S5).

  Thereafter, driving of the image sensor 212 is started to start an imaging operation (step S6). The shutter unit 208 is opened based on the opening time calculated in step S3 and is closed again (step S7). After closing the shutter unit 208, the driving of the image sensor 212 is stopped, and the image interface circuit 217 reads pixel data in the image sensor 212 (step S8). Here, the image processing controller 218 performs image processing on the pixel data read from the image sensor 212 in step S8 (step S9).

  Then, the image data processed in step S9 is temporarily stored in the buffer memory 219 (step S10). Further, the diaphragm 104 is returned to the open position (step S11). Thereafter, an image file of the image data is generated (step S12). In step S12, an image file of the image data is generated as a mode in which the image data temporarily stored in the buffer memory 219 in step S10 is written to the recording medium 221. Then, the image file of the image data generated in step S12 is recorded on the recording medium 221 (step S13). Thereafter, the process returns to step S1 to resume the live view.

  Hereinafter, the end operation of the live view mode will be described with reference to FIG. 5B, which is a flowchart showing the flow of processing in the Bucom 201 when the operation of the live view mode ends. Note that, when the live button 326 is pressed by the user during the live view mode operation in step S1, the process proceeds to the process of the flowchart shown in FIG.

  First, the live view display on the liquid crystal monitor 222 is terminated (step S21). Subsequently, the MF operation state set during the live view mode is canceled, and the AF operation state set before the live view mode is set again (step S22).

  Then, the opened shutter portion 208 is closed (step S23). Further, with the closing of the shutter unit 208, the driving of the image sensor 212 is stopped (step S24). Subsequently, the main mirror 202a is driven to the down position which is the initial position (step S25). Then, it will be in a standby state.

Hereinafter, a display example of an index for manual focus, which is one of the features of the in-focus state display device according to the first embodiment, will be described with reference to FIG. Here, FIG. 6A is a diagram illustrating a relationship between the focus evaluation value and the lens position of the photographing optical system 102 in the first embodiment. FIG. 6B is a diagram illustrating an example of display of the focus evaluation value at each lens position in the process of movement (1) illustrated in FIG. FIG. 6C is a diagram showing an example of display of the focus evaluation value in the process of movement (2) shown in FIG. FIG. 6D is a diagram showing an example of display when a focus evaluation value higher than the AF _peak is observed in the vicinity of the lens position L4 that is the focal point in the movement (2).

As shown in FIG. 6A, the focus evaluation value at the time of switching to the enlargement mode is set as AF _start . Then, it is assumed that the lens position of the photographing optical system 102 at this time is the lens position L1, and the focus evaluation value AF _start at the lens position L1 is in a considerably low state (a state in which it is considerably out of focus). The focus evaluation value calculation is repeatedly performed at a predetermined frame rate from the time when the mode is switched to the enlargement mode.

  Then, as shown in FIGS. 6B to 6D, in the first embodiment, the focus evaluation value at each lens position is displayed as a bar as the display bar 241 and the focus evaluation value at that time point is displayed. The peak hold display 242 is displayed at the same time in order to clearly indicate to the user the peak value up to.

  First, for the user, when the position of the photographing optical system 102 is moved from the lens position of the lens position L2 by the rotation operation of the focus ring 106, if the focus ring 106 is first rotated in either rotation direction, the user can adjust the position. It is unclear whether it will be in focus.

  Therefore, the user once rotates the focus ring 106 in any desired direction to move the position of the photographing optical system 102. For example, here, when the out-of-focus state is worse than the position of the photographing optical system 102 at the position of the lens position L1 shown in FIG. This means that the focus ring 106 is rotated. Therefore, in such a case, the user only has to rotate the focus ring 106 in the opposite direction.

Therefore, when the user rotates the focus ring 106 in the opposite direction, the position of the photographing optical system 102 passes through the lens position L1 to the lens position L3 and becomes the lens position L4. At the position L4, the focus evaluation value reaches a peak (the most focused state). That is, at the lens position L4, the focus evaluation value becomes a peak value (AF _peak ).

  However, even when the position of the photographing optical system 102 is the lens position L4 and the focus evaluation value becomes a peak value, it is unclear to the user whether or not the value is the peak value at that time. . Therefore, it is considered that the user continues the rotation operation of the focus ring 106 even after the position of the photographing optical system 102 becomes the lens position L4.

  For example, when the position of the photographing optical system 102 is the lens position L5, the display image is slightly out of focus compared to the time of the lens position L4 (the photographing optical system from the lens position L1 to the lens position L5). The movement process 102 is referred to as movement (1)). Therefore, the user recognizes that the in-focus position has been passed, and performs an operation to reversely rotate the focus ring 106 and return it to the lens position L4 (the photographing optical system 102 for the movement (1)). The movement process of moving in the opposite direction is called movement (2)).

  In the first embodiment, as shown in FIGS. 6A to 6D, the peak hold display 242 is represented by two triangular marks and one line, but the peak hold is recognized by the user. Of course, any shape can be used as long as it can be achieved. That is, for example, even a single line can serve as a peak hold display.

As in the example shown in FIG. 6B, when the photographing optical system 102 is moved from the lens position L1 to the lens position L4, the focus evaluation value is always a peak value at the current lens position. The current focus evaluation value is displayed as a peak hold on the peak hold display 242 as a peak value. When the lens position L4 is passed, the focus evaluation value at the lens position L4 is AF _peak , which is the peak value. Therefore, the focus evaluation value at the lens position L4 is the peak value by the peak hold display 242. Is displayed as a peak hold.

  Therefore, the user can always recognize the peak value of the focus evaluation value by the peak hold display 242 and rotate the focus ring 106 so that the lens position of the photographing optical system 102 is aligned with the lens position L4. it can.

  FIG. 6C shows the display bar 241 and the peak after the user rotates the focus ring 106 and moves the position of the photographing optical system 102 to the position of the lens position L5 by the movement (1). A process of recognizing that the peak has already passed by the hold display 242 and moving the photographing optical system 102 to the lens position of the lens position L4 or to the lens position of the lens position L4 by rotating the focus ring 106 in reverse. 3 shows an example of display of the display bar 241.

Here, in the first embodiment, in the process of the movement (2), the user rotates the focusing ring 106 so that the display bar 241 coincides with the position of the peak hold display 242, and the photographing optical system 102 is rotated. In order to clearly indicate to the user that the lens position of the photographing optical system 102 coincides with the lens position L4 during the adjustment, the lens position of the photographing optical system 102 is adjusted to the lens position. The display form of the display bar 241 is changed once it matches L4. That is, the display form of the display bar 241 is changed when the focus evaluation value reaches the value of AF _peak .

  Thereby, the ease of focusing adjustment by MF in the process of the movement (2) is remarkably improved. In the example shown in FIG. 6C, the display form of the display bar 241 is changed by changing the display color of the display bar 241 (for example, when the display color of the display bar 241 is normally white). As described above, the lens position of the photographing optical system 102 is changed to black when it once matches the lens position L4, that is, the focal point).

  Various modifications can be considered as means for notifying the user that the lens position of the photographing optical system 102 coincides with the lens position L4, that is, the focal point. That is, although the case where the display color of the display bar 241 is changed is shown here, the texture pattern of the display bar 241 is changed (for example, changed to a stripe shape), or an in-focus display mark is separately provided and displayed. There are various methods such as voice notification.

By the way, after the display form of the display bar 241 is changed as described above, the lens position of the photographing optical system 102 is moved in the direction of the lens position L1 by a further rotation operation of the focus ring 106 by the user. If the lens position of the photographic optical system 102 deviates from the lens position L4, the peak hold display 242 displays the focus evaluation value at the lens position L4 as AF _{peak and} displays the display bar. The display form 241 returns to the normal display form, that is, the display form similar to the display form shown in FIG. In consideration of the fact that the lens position of the photographing optical system 102 is not already in focus, the display form of the display bar 241 should be returned to the normal display form (display form shown in FIG. 6B). Because there is. In this example, the display color of the display bar 241 is returned from black to white.

FIG. 6D shows a display example when a focus evaluation value higher than the AF _peak is observed in the vicinity of the lens position L4 that is the focal point in the movement (2). As shown in the figure, when a focus evaluation value higher than a predetermined level by the AF _peak is observed, the peak value of the new focus evaluation value is newly handled as an AF _peak .

That is, for example, when a new AF _peak is observed immediately before the user is notified of the focal point by changing the display color of the display bar 241, the position indicated by the peak hold display 242 is updated at that time. As a result, even if the user does not recognize that the peak value of the focus evaluation value has changed, the focus ring 106 is again rotated in the reverse direction by the user viewing the display bar 241, and the display bar 241. If the value pointed to matches the new AF _peak , the in-focus state is established and the above-mentioned in-focus notification is made.

On the other hand, when a new AF _peak is observed immediately after notifying the user of the focal point by changing the display color of the display bar 241, the display form of the display bar 241 is returned to the normal display form (in this example, The display color of the display bar 241 is changed from black to a normal display color, that is, white), and the display of the peak hold display 242 is updated to a new AF _peak . As a result, the user can recognize that the value of the AF _peak , which is the peak value of the focus evaluation value, has been updated, so that further focus adjustment can be easily performed.

Note that a situation where a focus evaluation value higher than the above AF _peak is observed near the lens position L4, which is the focal point, is a factor such as repeated variation in focus evaluation value calculation, subtle movement of the subject, or camera shake. It can easily happen if there exists.

  Hereinafter, transition of display on the actual liquid crystal monitor 222 in the enlargement mode will be described with reference to FIGS. 7A to 7F show the display on the liquid crystal monitor 222 when shooting in the enlargement mode using the center of a flower (including a stamen and pistil) as a subject that is often used in macro shooting. Is shown.

  First, FIG. 7A shows a display on the liquid crystal monitor 222 when the subject is completely in low contrast. In such a case, since the focus evaluation value is very low, the value indicated by the display bar 241 is a very low value, and the peak hold display 242 indicates the current upper surface of the display bar 241. ing.

  FIG. 7B shows a display on the liquid crystal monitor 222 when the subject is still out of focus. In such a case, the value indicated by the display bar 241 is still a low value, and the peak hold display 242 indicates the current upper surface of the display bar 241. Note that the lens position of the photographing optical system 102 at this time corresponds to the lens position L1 shown in FIGS. 6A and 6B, for example.

  FIG. 7C shows the state in which the focus ring 106 is further rotated in the in-focus direction by the user in the state shown in FIG. The display on the liquid crystal monitor 222 when the lens position of the optical system 102 is set is shown. At this time, the peak hold display 242 indicates the current upper surface of the display bar 241. At this time, the user can recognize that the vicinity of the lens position is the in-focus position from the in-focus level of the display image displayed in an enlarged manner, but cannot determine that this lens position is the in-focus position. Note that the lens position of the photographing optical system 102 at this time corresponds to a lens position L4 shown in FIGS. 6A and 6B, for example.

  Thereafter, when the focus ring 106 is further rotated in the same direction by the user, the lens position of the photographing optical system 102 becomes a position where the focus evaluation value slightly decreases from the peak value (see FIG. 7D). . Note that the lens position of the photographing optical system 102 at this time corresponds to the lens position L5 shown in FIGS. 6A and 6B, for example. At this time, as shown in FIG. 7 (d), the peak hold display 242 holds the same display as that shown in FIG. 7 (c). Therefore, the user sees the display bar 241 and the peak hold display 242 and recognizes that the focus evaluation value has already passed the lens position where the peak value is reached, and moves the focus ring 106 in the opposite direction. Rotate.

  Then, the focus ring 106 is rotated in the reverse direction by the user from the state shown in FIG. 7D, and the lens position (the lens position shown in FIG. 7C) when the focus evaluation value reaches the peak value is obtained. When the lens position of the photographing optical system 102 coincides to obtain an in-focus state, the display on the liquid crystal monitor 222 is as shown in FIG. That is, the display bar 241 reaches a position that coincides with the value indicated by the peak hold display 242 again by the rotation operation of the focus ring 106 by the user. At this time, as shown in FIG. 7E, the user is notified that the in-focus state has been achieved. Here, the display form (display color in this example) of the display bar 241 is changed for the notification. Note that the lens position of the photographing optical system 102 at this time corresponds to the lens position L4 shown in FIGS. 6A and 6C, for example.

As shown in FIG. _7E, when a new AF _peak is observed immediately after notifying the user that the display state (display color) of the display bar 241 has been changed to obtain the in-focus state. Displays on the liquid crystal monitor 222 as shown in FIG. That is, as shown in FIG. 7F, the display form (display color) of the display bar 241 is returned to the normal display form (display color), and the position indicated by the peak hold display 242 is updated. Note that the lens position of the photographing optical system 102 at this time corresponds to, for example, a lens position L4 shown in FIG.

  The operation control in the Bucom 201 for actually displaying the focus evaluation value shown in FIG. 6 in the live view mode will be described below with reference to the flowchart shown in FIG. The flowchart shown in FIG. 8 is also a flowchart showing in detail the process of step S1 in the flowchart shown in FIG. In addition, steps in the same flowchart that perform the same processing are denoted by the same step numbers and description thereof is also omitted.

  In the live view mode, the AF mode cannot be used. Therefore, even if the AF mode is selected by an AF mode selection switch (not shown) for switching to the AF mode, the mode is first forcibly switched to the MF mode (step S31). That is, first in step S31, the mode is switched to the MF mode in order to execute the live view mode.

  Subsequently, the main mirror 202a is moved to the up position, and the shutter unit 208 is opened (step S32). As a result, the total luminous flux enters the image sensor 212 through the opening. Thereafter, a peak excess flag flag_peak, which is an index for determining that the focus evaluation value has once exceeded the peak value, is initialized to 0 (step S33). The peak over flag flag_peak is a flag that is set or cleared in step S33, S46 and S51 described later.

  Then, it waits for the input of a synchronization signal (step S34). Here, the synchronization signal is a signal for obtaining a video signal by driving the image sensor 212 at predetermined intervals. For example, when the frame rate is 30 frames / s, the frame rate is such that a video signal is obtained 30 times per second. That is, in this case, a synchronization signal is input from the imaging interface circuit 217 every 33.33 ms.

  Thereafter, if it is determined that the synchronization signal has been input, the imaging interface circuit 217 performs the charge accumulation operation of the imaging element 212 (step S35). When the charge accumulation operation of the image sensor 212 is completed, image data is read by the image interface circuit 217 (step S36).

  Furthermore, a known calculation is performed on the current imaging data to calculate an AE evaluation value for evaluating the exposure, and an exposure amount at the next driving time of the image sensor 212 is calculated based on the calculation result (step S37). The image sensor 212 has a known electronic shutter function, and the charge accumulation time of the image sensor 212 is set in the same step based on the exposure amount calculated in step S37.

Subsequently, a focus evaluation value in a setting area (here, the setting area is the focus evaluation value calculation area 232 shown in FIG. 4C; the same applies hereinafter) is calculated, and the value is expressed as AF _now . To do. (Step S38). The focus evaluation value is a value obtained by performing high-pass filter processing on the output of the image sensor 212 to extract a high-frequency component and performing a known calculation, and various calculation formulas have been known conventionally. Yes. In addition, this focus evaluation value becomes a large value because the higher the focus, the higher the frequency component.

  Then, it is determined whether or not the display scale in the focusing meter 240 has been determined (step S39). Note that the display scale is not fixed immediately after the transition to the MF mode. Therefore, in this case, step S39 is branched to No and the process proceeds to step S40 described later. Once the process of step S40 is executed, step S39 is branched to YES and the process proceeds to step S41 described later. That is, the process does not proceed to step S40 until the display scale is initialized. Here, as an example where the display scale is initialized, for example, a case where a start switch (not shown) or the like described later is operated can be cited.

When step S39 is branched to NO, the maximum value and the minimum value of the focus meter 240 are determined based on the latest focus evaluation value AF _now acquired in step S38 (step S40). Regarding the determination of the maximum value and the minimum value of the focusing meter 240, for example, the maximum value of the display bar 241 is set to AF _now × 50, and the display bar 241 is not displayed at all as the minimum value. The hour value is set to 0, and the display scale of the focusing meter 240 is automatically scaled.

Thereafter, the current focus evaluation value AF _now is displayed as the display bar 241 in the focus meter 240 on the display scale determined in step S40 (step S41). Subsequently, it is determined whether or not the peak over flag flag_peak is 0 (step S42).

When the process proceeds to step S42 for the first time, since the peak excess flag flag_peak is set to 0 in step S33, the process branches to YES and the process proceeds to step S43. In step S43, it is determined whether or not the value of AF _now is a peak value. If it is determined in step S43 that the AF _now value is a peak value, the above-described peak hold display is performed and the peak value AF _peak is updated to the current AF _now value (step S44).

On the other hand, when step S43 is branched to NO and after the process of step S44,
AF _peak -AF _now > first predetermined value (1)
It is determined whether or not AF _peak and AF _now satisfy the relationship (step S45). Here, the first predetermined value means a threshold value for determining whether or not the value of AF _now is lower than the value of AF _{peak by} a predetermined value, as shown in FIG. 8B. is doing. That is, satisfying the above equation (1) indicates that the rotation is further performed after the focus evaluation value once exceeds the peak value by the focus ring 106 being rotated by the user, as can be seen from FIG. 8B. It means that the value of AF _now is sufficiently lowered after being continued and exceeding the peak value. If step S45 is branched to NO, the process returns to step S34.

  When step S45 is branched to YES, the peak excess flag flag_peak is set to 1 to indicate that the focus evaluation value has exceeded the peak (step S46). Thereafter, the process returns to step S34.

By the way, if it is determined in step S46 that the focus evaluation value has once exceeded the peak and the peak excess flag flag_peak is set to 1, the process branches to NO in step S42 where the process proceeds again. Here, when step S42 is branched to NO,
| AF _peak -AF _now | <second predetermined value (2)
It is determined whether or not AF _peak and AF _now satisfy the relationship (step S47). Here, the second predetermined value refers to a change in AF _peak value due to a subtle change in the subject, a change in luminance, or the like after the focus evaluation value has once exceeded the peak in step S46. This is a value set in consideration of the possibility of a change in the value of AF _peak due to repeated variation in the focus evaluation value calculation. That is, the second predetermined value is a value for creating a dead zone in the peak value of the focus evaluation value necessary for appropriately determining the state of the peak value of the focus evaluation value. As shown in FIG. 8B, the second predetermined value is smaller than the first predetermined value.

When step S47 is branched to YES, AF _now again coincides with AF _peak , so that the user is notified as shown in FIG. 7E (step S48). Here, as described above, the display form of the display bar 241, that is, the display color is changed. At this time, when the second release switch is turned on by the user, the photographing operation is executed in the focused state. If the second release switch is not turned on by the user, the process returns to step S34 again.

On the other hand, when step S47 is branched to NO, it is still a case where AF _now does not coincide with AF _peak again.
AF _now > AF _peak + second predetermined value (3)
It is determined whether or not AF _now and AF _peak satisfy the relationship (step S49).

If it is determined in step S49 that the expression (3) is not satisfied, it is determined in step S46 that the focus evaluation value has once _exceeded the _peak , and then the AF _now value is changed to the AF _peak value again. This is the case when they do not match. Therefore, step S49 is branched to NO, and the display form of the display bar 241 is returned to the normal display form or the normal display form is maintained (step S52). Thereafter, the process returns to step S34.

Even when the display color of the display bar 241 is changed in step S48, and _AFnow ≦ _AFpeak + second predetermined value is satisfied in step S49, the display color is restored to the original in step S52.

On the other hand, when it is determined in step S49 that AF _now and AF _peak satisfy the relationship of the above expression (3), after the display form (display color) of the display bar 241 is changed in step S48, a larger value is obtained. This is a case where the value AF _peak is observed. Therefore, in this case, step S49 is branched to YES, the peak hold display is performed with the value of AF _now , and the value of AF _peak is updated (step S50). Since the value of AF _peak is updated in step S50, the peak over flag flag_peak is initialized to 0 (step S51), and the process proceeds to step S52. By the process in step S51, the next step S42 branches to YES.

  Hereinafter, the steps of the interrupt process will be described.

  First, when a display start switch (not shown) is pressed by the user during the processes in steps S34 to S52, the process proceeds to the process of step S33 in the interrupt process of Bucom 201, and the live view display is displayed again from the beginning. This is performed (step S53).

  In addition, when the second release switch is turned on by the user while the live view display update operation is being performed at the predetermined frame rate during the processing in steps S34 to S52, the Bucom 201 is switched on. In the interruption process, the sequence in the flowchart is exited, and the process proceeds to the process of step S2 described with reference to FIG. 5, and the photographing operation is performed (step S54). At this time, the display bar 241 is not displayed.

  Further, if the user presses the live button 326 while the live view display update operation is being performed at a predetermined frame rate during the processing in steps S34 to S52, the Bucom 201 interrupts. In the process, the sequence in the flowchart is exited, and the process proceeds to the process in step S21 described with reference to FIG. 5 and the live view mode end operation is performed (step S55).

  As described above, according to the first embodiment, it is possible to provide a camera focus state display device that achieves the following effects.

  First, the peak hold display 242 allows the user to clearly recognize the peak value of the focus evaluation value. Further, when the lens position of the photographic optical system 102 once exceeds the position where the focus evaluation value reaches the peak value and then reaches the position where the focus evaluation value reaches the peak value again, as described above. Since the notification is made, the user can perform MF very easily.

  In this way, by notifying the user that the lens position of the photographing optical system 102 coincides with the in-focus point, the user is in focus as compared with the case of the peak hold display 242 or the display bar 241 alone. Can be recognized more accurately, and focusing with MF becomes easier.

  Further, since the focus evaluation value is automatically scaled and displayed on the liquid crystal monitor 222, the fluctuation width of the display bar 241 can be maintained at a predetermined level without being greatly influenced by the subject condition. Therefore, according to the focus state display device of the camera according to the first embodiment, for example, the display bar 241 hardly fluctuates even if the subject is actually in focus for a certain condition. In the subject of the condition, the display bar 241 rarely swings to the vicinity of the maximum value.

  In the focus state display device for a camera according to the first embodiment, a predetermined function is provided in that the user can easily perform MF even by performing only a part of the functions, that is, the peak hold display 242 or the notification. The effect of can be obtained. Needless to say, a greater effect can be obtained by combining the above-described functions.

  By the way, the absolute value of the focus evaluation value varies greatly depending on the nature of the subject, the contrast of the subject, the luminance, camera shake by the user, and the like. Therefore, when the focus evaluation value is displayed by setting the maximum value and the minimum value of the display scale of the focus meter 240 to values determined in advance, the display bar 241 may shake greatly or slightly depending on the subject and shooting conditions. Thus, although a peak can be detected, it is difficult to say that the display bar 241 plays a role for facilitating manual focus when viewed from a general user who has little knowledge about the focus evaluation value. However, according to the focus state display device of the camera according to the first embodiment, the display scale of the focus meter 240 is based on the focus evaluation value calculated based on the video signal acquired in actual shooting. Since the maximum value and the minimum value are determined, the fluctuation width of the display bar 241 is stabilized, so that the user can easily grasp the in-focus position in the MF.

[Second Embodiment]
Next, a camera focus state display device according to a second embodiment of the present invention will be described. Only contents different from the camera focus state display device according to the first embodiment will be described.

  In the second embodiment, the focus evaluation value is calculated and displayed as the display bar 241 even in the non-enlargement mode described above. Therefore, in the second embodiment, a second focus evaluation value calculation area 332 that is a focus evaluation value calculation area in the non-enlarging mode is set. Therefore, the focus evaluation value calculation unit 2 calculates the focus evaluation value in the second focus evaluation value calculation area 332 in the non-enlarging mode. Further, the focus evaluation value calculated in the second focus evaluation value calculation area 332 is displayed as a display bar 241 in the focus meter 240.

  The second focus evaluation value calculation area 332 that is a focus evaluation value calculation area in the non-enlargement mode is different from the focus evaluation value calculation area 232 that is a focus evaluation value calculation area in the enlargement mode. The reason for setting as an area will be described later.

  FIG. 9 is a diagram showing a display screen on the liquid crystal monitor 222 in the non-enlarging mode of the camera equipped with the camera focus state display device according to the second embodiment. Hereinafter, the difference between the focus evaluation value calculation area 232 and the second focus evaluation value calculation area 332 will be described with reference to FIG.

  In general, in live view display in the non-enlarging mode, electrical signals from all of the pixels of the image sensor 212 are not read out and used via the imaging interface circuit 217.

  This is because it takes a certain amount of time to read out electrical signals from all the pixels in the image sensor 212, so it is difficult to read out electrical signals from all the pixels in the image sensor 212 within a predetermined frame rate. This is because the number of pixels exceeding the resolution is not necessary. Therefore, in the non-enlarging mode, a through image display is performed by thinning out the number of pixels in the image sensor 212 considerably.

  By the way, in the enlargement mode, the image shown in a part of the image displayed on the liquid crystal monitor 222 is enlarged and displayed. Therefore, as described above, the number of pixels thinned out in the non-enlargement mode is insufficient for display in the enlargement mode. Therefore, only the image data in the enlargement box 230 is used for through image display with a thinning rate reduced.

  As described above, the number of pixels used for through image display differs between the enlargement mode and the non-enlargement mode. Therefore, in order to ensure the accuracy of the focus evaluation value calculation, it is necessary to vary the number of pixels in the region where the focus evaluation value calculation is performed in the non-enlargement mode and the enlargement mode. In view of such circumstances, in the second embodiment, the focus evaluation value calculation area in the non-enlarging mode, that is, the second focus evaluation value calculation area 332 is referred to as the focus evaluation value calculation area 232. Are set as different areas. Normally, the second focus evaluation value calculation area 332 is set as a larger area than the focus evaluation value calculation area 232.

  As described above, according to the second embodiment, in addition to the same effects as the camera focus state display device according to the first embodiment, the camera focus state display device has the following effects. Can be provided.

  That is, according to the focus state display device of the camera according to the second embodiment, it is possible to calculate and display a highly accurate focus evaluation value not only in the enlargement mode but also in the non-enlargement mode. Focusing with MF can be performed easily and accurately.

  As mentioned above, although this invention was demonstrated based on 1st Embodiment and 2nd Embodiment, this invention is not limited to embodiment mentioned above, A various deformation | transformation and application are within the range of the summary of this invention. Of course it is possible.

  For example, in the first embodiment and the second embodiment, the case where the camera focus state display device is mounted on a single-lens reflex camera with interchangeable lenses has been described as an example, but other hill-climbing AF functions and MF functions are also described. Of course, the above-described embodiments can also be applied to other types of cameras having a combination of the above and the like, that is, still cameras, video cameras, and the like.

  In the first and second embodiments, the focus meter 240 is configured to indicate the degree of focus by the length of the display bar 241. However, the focus meter 240 can be recognized and determined at a glance by the user. For example, instead of the display bar 241, the degree of focusing may be expressed by the shape of another figure. For example, instead of the display bar 241, a circular display indicator is employed, and the degree of focus is expressed by the radius of the circular display indicator. Further, an example in which a triangular indicator having a fixed size is employed instead of the display bar 241 and the degree of focus is expressed by moving the triangular indicator in the liquid crystal monitor 222 within a predetermined range from side to side. It is done.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

1 is a block diagram showing a main configuration of a focus state display device according to a first embodiment of the present invention. The block diagram which showed in detail the structure of the camera carrying the focus state display apparatus which concerns on 1st Embodiment of this invention. The figure which shows the rear view of the camera carrying the focus state display apparatus which concerns on 1st Embodiment of this invention. (A) thru | or (c) is a figure which shows the display screen in the liquid crystal monitor at the time of live view mode. (A) is a flowchart showing a flow of operation control processing in Bucom of a shooting operation in a live view mode in a camera equipped with the focus state display device according to the first embodiment of the present invention. FIG. 6B is a flowchart showing the flow of processing in Bucom when the operation of the live view mode is terminated. (A) is a figure which shows the relationship between the focus evaluation value in 1st Embodiment of this invention, and the lens position of an imaging optical system. (B) is a figure which shows an example of a display of the focus evaluation value in each lens position shown to (a). (C) is a figure which shows an example of a display of the focus evaluation value in the process of the movement (3) shown to (a). FIG. 6D is a diagram showing an example of display when a higher focus evaluation value is observed near the lens position that is the focal point in the movement (2). (A) is a figure which shows the display in a liquid crystal monitor when a to-be-photographed object is completely low contrast. FIG. 6B is a diagram showing a display on the liquid crystal monitor when the subject is still out of focus. (C) shows a case where, from the state shown in (b), the focus ring is rotated in the in-focus direction by the user, and the lens position of the photographing optical system is set to the lens position where the focus evaluation value becomes the peak value. The figure which shows the display in a liquid crystal monitor. (D) is a diagram showing a display on the liquid crystal monitor when the focus ring is further rotated in the same direction by the user and the lens position of the photographing optical system is a position where the focus evaluation value is slightly lower than the peak value. . (E) is taken at the lens position (the lens position shown in FIG. 7C) when the focus ring is rotated in the reverse direction from the state shown in (d) and the focus evaluation value reaches the peak value. The figure which shows the display in a liquid crystal monitor when the lens position of an optical system corresponds and has acquired the focused state. (F) shows a case where a new AF _peak is observed immediately after notifying the user that the in-focus state has been obtained by changing the display form (display color) of the display bar as shown in (e). The figure which shows the display in a liquid crystal monitor. FIG. 6A is a flowchart illustrating operation control in a live view mode. FIG. 6B is a diagram illustrating a correlation between a lens position of the photographing optical system and a focus evaluation value. The figure which shows the display screen in the liquid crystal monitor at the time of the non-expansion mode of the camera by which the focus state display apparatus of the camera which concerns on 2nd Embodiment of this invention is mounted.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Imaging part, 2 ... Focus evaluation value calculating part, 3 ... Peak detection part, 4 ... Meter form control part, 5 ... Focus meter preparation part, 6 ... Display part, 7 ... Monitor, 101 ... Micro for lens control Computer 102: Shooting optical system 103 ... Lens drive mechanism 105 ... Aperture drive mechanism 106 ... Focus ring 201 ... Microcomputer for body control 202a ... Main mirror 204 ... Photometry circuit 205 ... AF sensor unit 208 ... Shutter unit 212 ... Imaging device 217 ... Imaging interface circuit 218 ... Image processing controller 219 ... Buffer memory 221 ... Recording medium 222 ... Liquid crystal monitor 230 ... Enlargement box 232 ... Focus evaluation value calculation area 240 ... Focus meter, 241 ... Display bar, 242 Peak hold display, 303 ... mode dial, 316 ... main dial, 317 ... AF frame button 326 ... live button 332 ... second Go focus evaluation value calculation region.

Claims (7)

A photographic lens capable of manual focus by the photographer;
Imaging means for forming a subject image through the photographing lens and converting the subject image into a video signal;
A focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at a predetermined time interval based on an output of the imaging means;
Evaluation value display means for displaying the calculation result of the focus evaluation value calculation means while the photographing lens is being focused manually by the photographer;
While the photographing lens is being focused manually by the photographer, the maximum value of the focus evaluation value is determined based on the output of the focus evaluation value calculation means, and the level of the maximum value is determined. Maximum value display means for displaying;
A focus state display device for a camera. A photographic lens capable of manual focus by the photographer;
Imaging means for forming a subject image through the photographing lens and converting the subject image into a video signal;
A focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at a predetermined time interval based on an output of the imaging means;
Evaluation value display means for displaying the calculation result of the focus evaluation value calculation means while the photographing lens is being focused manually by the photographer;
While the photographing lens is being manually focused by the photographer, the maximum value of the focus evaluation value is determined based on the output of the focus evaluation value calculation means, and the latest focus evaluation value Is a maximum value coincidence judging means for judging whether or not it is coincident with the maximum value again after becoming a value lower than a predetermined value from the maximum value,
When the maximum value match determination means determines that the focus evaluation value again matches the maximum value, the maximum value match notification means for notifying the photographer to that effect,
A focus state display device for a camera. A photographic lens capable of manual focus by the photographer;
Imaging means for forming a subject image through the photographing lens and converting the subject image into a video signal;
A focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at a predetermined time interval based on an output of the imaging means;
Evaluation value display means for displaying the calculation result of the focus evaluation value calculation means while the photographing lens is being focused manually by the photographer;
While the photographing lens is being focused manually by the photographer, the maximum value of the focus evaluation value is determined based on the output of the focus evaluation value calculation means, and the level of the maximum value is determined. Maximum value display means for displaying;
While the photographing lens is being focused manually by the photographer, the latest focus evaluation value is a value that is lower than the maximum value output from the maximum value display means by a predetermined value or more. A maximum value coincidence judging means for judging again whether or not the above maximum value is matched,
When the maximum value match determination means determines that the focus evaluation value again matches the maximum value, maximum value match notification means for notifying the photographer to that effect;
A focus state display device for a camera.   4. The focus state display device for a camera according to claim 2, wherein the maximum value coincidence notification unit performs the notification by changing a color displayed by the evaluation value display unit.   The evaluation value display means determines a display scale when displaying the calculation result of the focus evaluation value calculation means based on the output of the focus evaluation value calculation means. The focus state display device for a camera according to any one of the above. A photographic lens capable of manual focus by the photographer;
Imaging means for forming a subject image through the photographing lens and converting the subject image into a video signal;
A focus evaluation value calculating means for calculating a focus evaluation value indicating a focus state of the photographing lens at a predetermined time interval based on an output of the imaging means;
Evaluation value display means for displaying the calculation result of the focus evaluation value calculation means while the photographing lens is being focused manually by the photographer;
To switch to the non-enlarging mode, which is a mode for displaying a substantially entire image corresponding to the video signal, or the enlarged mode, which is a mode for displaying a through image by enlarging a part of the image corresponding to the video signal Mode switching means;
Comprising
The focus evaluation value calculation means sets the focus evaluation value calculation area, which is a target area for performing the focus evaluation value calculation in the image corresponding to the video signal, as a different area between the non-enlargement mode and the enlargement mode. A focus state display device for a camera.   The camera according to claim 6, wherein the focus evaluation value calculation unit sets the focus evaluation value calculation area in the non-enlargement mode to be larger than the focus evaluation value calculation area in the enlargement mode. Focus state display device.

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