JP2007036395A - Digital camera and method of setting photography mode thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent inconsistency in the operation of a quick photography mode in a digital camera having both a microphotography mode and the quick photography mode. <P>SOLUTION: When a macro setting button is provided on the back of the digital camera is pressed for setting the digital camera to the microphotography mode, the CPU of the digital camera determines whether the quick photography mode has been set. When the CPU determines that the quick photography mode has already been set, the CPU prevents the microphotography mode from being set. In this manner, when one of photography modes is set, the other is not set to prevent respective photography modes from being set simultaneously, thus preventing the inconsistency in the operation of the quick photography mode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a plurality of shooting modes including a macro shooting mode and a quick shooting mode, and sets / cancels these shooting modes according to the shooting scene, and performs a contrast type autofocus to capture a subject image. The present invention relates to a digital camera and a shooting mode setting method thereof.

  Digital cameras that convert a subject image captured by a solid-state imaging device such as a CCD into digital image data and store it in a storage medium such as a built-in memory or a memory card have become widespread. Most digital cameras in recent years have a so-called contrast autofocus function that calculates the focus evaluation value that represents the contrast of the image from the image data and automatically adjusts the focus lens. (See Patent Document 1).

  In contrast-based autofocus, the focus lens is moved within a predetermined search range, multiple focus evaluation values are calculated, and the focus lens is moved to the position where the focus evaluation value is the highest. . In this type of autofocus, since it takes about 1 second to focus, there are cases in which shooting is performed in a so-called out-of-focus state when shooting is performed instantaneously.

To deal with this problem, the auto-focus time is reduced compared to the normal shooting mode, and a quick shooting mode is provided for use in scenes where you do not want to miss a momentary photo opportunity, such as an athletic meet. Some digital cameras do this. In the quick shooting mode, it is assumed that the subject is almost in the vicinity of, for example, 3 m to 30 m, and the search range on the near side is reduced, thereby reducing the time required for autofocus.
Japanese Patent Laid-Open No. 2002-33569

  By the way, some digital cameras are equipped with a macro shooting mode for performing so-called close-up shooting that approaches a subject up to several centimeters. In this macro shooting mode, it is assumed that the subject is within a range of several centimeters to several tens of centimeters, and an autofocus search may be performed within this range.

  However, in a digital camera that has both the macro shooting mode and the quick shooting mode described above, if both are set at the same time, the macro shooting mode is reduced despite the fact that the search range on the near side is reduced by the quick shooting mode setting. The near side will be searched depending on the setting of. In this way, there is a contradiction in the search range of autofocus, and there is a problem that the time required for autofocus becomes long even though the quick shooting mode is set.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent a contradiction caused in the operation of the quick shooting mode in a digital camera having both the macro shooting mode and the quick shooting mode.

  In order to achieve the above object, a digital camera according to the present invention provides an image sensor that captures a subject image transmitted through an imaging lens and outputs image data corresponding to the subject image, and a focus lens included in the imaging lens. A lens moving means for moving in the axial direction, an evaluation value calculating means for calculating a focus evaluation value indicating the level of contrast of an image represented by the image data by extracting a high-frequency component from the image data, and a focus lens Based on the focus evaluation value in a predetermined search range according to movement, a focus control means for performing autofocus of contrast method, a macro shooting mode that enables close-up shooting, and the autofocus over the normal shooting mode Shooting to set / cancel multiple shooting modes, including quick shooting mode that reduces the time required for And mode setting means, characterized in that said macro shooting mode and the quick shooting mode is a shooting mode control means for preventing from being set at the same time.

  The photographing mode control means preferably does not set the other when one of the macro photographing mode and the quick photographing mode is set.

  The shooting mode control means is set when one of the macro shooting mode and the quick shooting mode is set and the other setting is instructed via the shooting mode setting means. It is good also as a structure which cancels | releases one said imaging | photography mode and is setting the other said imaging | photography mode instruct | indicated.

  Further, it is preferable that a two-stage release button consisting of half-press and full-press is provided, and the focusing control means performs the autofocus in response to the half-press operation of the release button.

  Furthermore, it is preferable that the quick shooting mode shortens the time required for the autofocus by reducing the search range closer to the normal shooting mode.

  The shooting mode setting method of the present invention includes an image sensor that captures a subject image that has passed through an imaging lens and outputs image data corresponding to the subject image, and a focus lens included in the imaging lens in the optical axis direction. A lens moving means for moving, an evaluation value calculating means for calculating a focus evaluation value indicating a contrast level of an image represented by the image data by extracting a high-frequency component from the image data, and according to the movement of the focus lens A focus control means for performing a contrast-type autofocus based on the focus evaluation value in a predetermined search range, and a macro shooting mode that enables close-up shooting, and the autofocus over the normal shooting mode. A digital camera with multiple shooting modes, including a quick shooting mode that reduces the time required for In La, and the macro shooting mode and the quick shooting mode is characterized by preventing from being set at the same time.

  At this time, when one of the macro shooting mode and the quick shooting mode is set, it is preferable not to set the other.

  Further, when one of the macro shooting mode and the quick shooting mode is set and the other setting is instructed, the one shooting mode that has been set is canceled and the other is instructed. The shooting mode may be set.

  According to the present invention, since the macro shooting mode and the quick shooting mode are prevented from being set at the same time, even in a digital camera having both of these shooting modes, there is a contradiction in the operation of the quick shooting mode. There is nothing.

  1 and 2 show the external appearance of the digital camera 2. As shown in the perspective view of FIG. 1, a lens barrel 11 that holds an imaging lens 10 is provided on the front surface of the digital camera 2. On the upper surface of the digital camera 2, a release button 12, a power switch 13, and a mode dial 14 are provided. Further, a memory card slot (not shown) in which a memory card 52 (see FIG. 3) is detachably loaded is provided on the side surface, and the lid 15 covers this memory card slot.

  As is well known, the power switch 13 is used when turning on / off the power of the digital camera 2. The digital camera 2 can select a still image shooting mode for shooting still images, a movie shooting mode for shooting movies, a playback mode for displaying captured images on the LCD 22, and a setting mode for performing various settings. . Switching between these modes is performed by rotating the mode dial 14. In the moving image shooting mode, along with shooting of moving images, surrounding sounds are recorded via a microphone (not shown).

  The release button 12 is a two-stage push switch. After the framing of the subject by the LCD 22, when the release button 12 is lightly pressed (half-pressed), various shooting preparation processes such as automatic exposure adjustment (AE) and automatic focus adjustment (AF) are performed. In this state, when the release button 12 is pressed once more (fully pressed), the imaging signal for one screen on which the imaging preparation processing has been performed is converted into image data. The converted image data is stored in the memory card 52 after, for example, various image processing and compression processing are applied.

  FIG. 2 is a plan view of the digital camera 2 as viewed from the back. A finder eyepiece window 21, a liquid crystal display (LCD) 22, and an operation unit 23 that constitute an electronic viewfinder are provided on the back surface of the digital camera 2. The LCD 22 displays, for example, captured images, so-called through images, and various menu screens. The operation unit 23 is a zoom operation button 24 for changing the zoom lens 30 (see FIG. 3) of the imaging lens 10 to the wide side or the tele side, when displaying a menu screen on the LCD 22, or when determining a selection content. The menu button 25 is operated, and the cross key 26 is used to move the cursor in the menu screen.

  Here, in addition to the normal shooting mode, the digital camera 2 performs a macro shooting mode that allows close-up shooting, which approaches the subject up to about several centimeters, and shooting preparation processing that is performed when the release button 12 is half-pressed. Quick shooting mode that shortens the time required. In this quick shooting mode, by shortening the time for the shooting preparation process, the shooting preparation process is completed even if the photographer presses it all at once without intentionally half-pressing it. As a result, it is possible to perform in-focus shooting without missing a momentary photo opportunity.

  In addition to the above, the operation unit 23 is provided with a macro setting button 27 for setting / canceling the macro shooting mode and a quick setting button 28 for setting / canceling the quick shooting mode. Each shooting mode is set by pressing the setting buttons 27 and 28 once, and is canceled by pressing again. That is, the macro setting button 27 and the quick setting button 28 constitute the photographing mode setting means described in the claims. Note that, for example, an icon may be displayed on the LCD 22 or a dedicated lamp may be turned on to notify the user that each shooting mode is set.

  FIG. 3 is a block diagram schematically showing the internal configuration of the digital camera 2. The imaging lens 10 includes a zoom lens 30, a diaphragm 31, and a focus lens 32 arranged along the optical axis L. A lens motor 33 is connected to the zoom lens 30. The lens motor 33 moves the zoom lens 30 to the wide angle side or the telephoto side in conjunction with the operation of the zoom operation button 24. An iris motor 34 is connected to the diaphragm 31. The iris motor 34 adjusts the amount of light incident from the zoom lens 30 by changing the aperture area of the diaphragm 31 during the shooting preparation process when the release button 12 is half-pressed. A lens motor (lens moving means) 35 is connected to the focus lens 32. The lens motor 35 moves the focus lens 32 to the close side or the infinity side in response to zooming of the zoom lens or half-pressing of the release button 12.

  Each motor 33, 34, 35 is connected to a motor driver 36. The motor driver 36 is connected to a CPU 37 that comprehensively controls the digital camera 2, and transmits drive pulses to the motors 33, 34, and 35 based on control signals from the CPU 37. Each of the motors 33, 34, and 35 rotates the rotation shaft according to the drive pulse. As each motor 33, 34, 35, for example, a stepping motor is used.

  Behind the imaging lens 10 is a CCD (imaging device) 38 that captures a subject image that has passed through the imaging lens 10. A timing generator (TG) 39 controlled by the CPU 37 is connected to the CCD 38, and the shutter speed of the electronic shutter is determined by a timing signal (clock pulse) input from the TG 39.

  The imaging signal output from the CCD 38 is input to a correlated double sampling circuit (CDS) 40, and is output as R, G, B image data that accurately corresponds to the accumulated charge amount of each cell of the CCD 38. The image data output from the CDS 40 is amplified by an amplifier (AMP) 41 and converted into digital image data by an A / D converter (A / D) 42.

  The image input controller 43 is connected to the CPU 37 via the bus 44, and controls each part of the CCD 38, the CDS 40, the AMP 41, and the A / D 42 in accordance with a control command from the CPU 37. The image data output from the A / D 42 is temporarily recorded in the SDRAM 45.

  The image signal processing circuit 46 reads the image data from the SDRAM 45, performs various image processing such as gradation conversion, white balance correction, and γ correction processing, and records the image data in the SDRAM 45 again. The YC conversion processing circuit 47 reads out the image data subjected to various processes by the image signal processing circuit 46 from the SDRAM 45, and converts it into a luminance signal Y and color difference signals Cr and Cb.

  The VRAM 48 is a memory for outputting a through image to the LCD 22, and stores image data that has passed through the image signal processing circuit 46 and the YC conversion processing circuit 47. The VRAM 48 has a memory for two frames so that image data can be written and read in parallel. The image data stored in the VRAM 48 is converted into an analog composite signal by the LCD driver 49 and displayed as a through image on the LCD 22.

  The compression / decompression processing circuit 50 compresses the image data YC converted by the YC conversion processing circuit 47 in a predetermined compression format such as TIFF or JPEG. The compressed image data is stored in the memory card 52 via the media controller 51.

  In addition to the release button 12 and the operation unit 23, an EEPROM 53 is connected to the CPU 37. The EEPROM 53 stores various control programs and setting information. The CPU 37 reads these pieces of information from the EEPROM 53 to the SDRAM 45, which is a working memory, and executes various processes.

  Also, the SDRAM 45 is provided with a macro flag 45a and a quick flag 45b for storing whether or not each shooting mode is set. When the setting buttons 27 and 28 are pressed and the respective shooting modes are set, the CPU 37 sets the corresponding flags 45a and 45b to store in the SDRAM 45 that the shooting mode is in the set state. When the setting buttons 27 and 28 are pressed again to release the set shooting modes, the corresponding flags 45a and 45b are lowered. The flags 45a and 45b may be raised or lowered when setting each shooting mode, as opposed to the above.

  Further, the bus 44 detects whether the exposure amount, that is, whether the shutter speed of the electronic shutter and the aperture value of the aperture 31 are appropriate for shooting, and detects whether the white balance is appropriate for shooting. The detection circuit 54 is connected to an AF detection circuit (evaluation value calculation means) 55 that detects whether or not the focus adjustment of the imaging lens 10 is appropriate for photographing.

  The AE / AWB detection circuit 54 detects the appropriateness of the exposure amount and the white balance based on the integrated value of the luminance signal Y of the image data YC converted by the YC conversion processing circuit 47 and the color difference signals Cr and Cb. This detection result is transmitted to the CPU 37. The CPU 37 controls the operations of the diaphragm 31 and the CCD 36 based on the detection result transmitted from the AE / AWB detection circuit 54.

  The AF detection circuit 55 performs so-called contrast AF control, calculates a focus evaluation value representing the contrast of the image from the image data digitized by the A / D 42, and sends the calculation result to the CPU 37. Send. The focus evaluation value is obtained by performing contour extraction processing with a high-pass filter or the like on a specific area of the image, for example, image data of the central portion of the shooting angle of view, and extracting the contour signal and the central portion of the image data. It is obtained by integrating the luminance value. Note that the larger the focus evaluation value is, the more high-frequency components are in the portion, and the portion is in focus.

  As shown in FIG. 4, the CPU 37 drives the lens motor 35 during the shooting preparation process when the release button 12 is half-pressed to move the focus lens 32 from the closest distance to infinity or from infinity to the closest distance. While moving (searching) by d, the AF evaluation circuit 55 calculates a focus evaluation value (indicated by a black circle in the figure) at each point. Then, the point where the focus evaluation value is maximized is determined as the in-focus position, and the focus lens 32 is moved to that point. That is, the CPU 37 corresponds to the focusing control means described in the claims.

  Also, as shown in FIG. 4, the AF search range is different in each shooting mode, such as 60 cm to infinity in the normal shooting mode, 1 m to infinity in the quick shooting mode, and 6 cm to 80 cm in the macro shooting mode. As can be seen, the search range in the quick shooting mode is shorter than the search range in the normal shooting mode. That is, in the quick shooting mode, it is assumed that the subject is almost in the vicinity of, for example, 3 m to 30 m, and the time required for AF is shortened by reducing the search range closer to the normal shooting mode. Is. These search ranges are merely examples, and are not limited to the above. Further, it is known that when an optical plastic lens is used for the imaging lens 10, the curvature of the lens changes depending on the temperature and the focal length changes. For this reason, a so-called over search region in which the temperature characteristics of the lens are anticipated may be provided at both ends of each search range, ie, near and infinity.

  Next, the operation of the digital camera 2 configured as described above will be described with reference to the flowcharts shown in FIGS. When the digital camera 2 is set to the macro shooting mode, the macro setting button 27 provided on the back surface of the digital camera 2 is pressed. The CPU 37 that has detected the pressing of the macro setting button 27 accesses the SDRAM 45, checks the quick flag 45b, and determines whether or not the quick shooting mode is set.

  The CPU 37, which has determined that the quick flag 45b is down and the quick shooting mode is not set, sets the digital camera 2 to the macro shooting mode, accesses the SDRAM 45, sets the macro flag 45a, and sets the macro shooting mode. Is stored in the SDRAM 45. On the other hand, the CPU 37 that determines that the quick shooting mode 45b is set and the quick shooting mode is already set does not set the macro shooting mode.

  On the other hand, when the digital camera 2 is set to the quick shooting mode, the quick setting button 28 provided on the back surface of the digital camera 2 is pressed. The CPU 37 that has detected the pressing of the quick setting button 28 accesses the SDRAM 45, checks the macro flag 45a, and determines whether or not the macro shooting mode is set.

  The CPU 37, which has determined that the macro flag 45a is down and the macro shooting mode is not set, sets the digital camera 2 to the quick shooting mode, accesses the SDRAM 45, sets the quick flag 45b, and sets the quick shooting mode. Is stored in the SDRAM 45. On the other hand, the CPU 37 that determines that the macro shooting mode 45a is already set and the macro shooting mode is already set does not set the quick shooting mode. That is, the CPU 37 and the SDRAM 45 constitute the photographing mode control means described in the claims.

  As shown in FIG. 4, the AF search range differs greatly between the macro shooting mode and the quick shooting mode. For this reason, if these shooting modes are set at the same time, the search range becomes wider than in the normal shooting mode, resulting in a contradiction that the time required for AF becomes longer despite the quick shooting mode being set. End up. On the other hand, in this example, the state of each flag 45a, 45b is confirmed, and when one shooting mode is set, the other is not set, and the macro shooting mode and the quick shooting mode are set simultaneously. Therefore, there is no contradiction in the operation of the quick shooting mode.

  In the above-described embodiment, the shooting mode setting means includes the macro setting button 27 and the quick setting button 28, and each shooting mode is set / released in response to these pressing operations. Without limitation, for example, the shooting mode setting means includes a menu button 25, a cross key 26, and the like. By pressing the menu button 25, each shooting mode can be set / released from the menu screen displayed on the LCD 22. You may make it perform.

  Further, in the above embodiment, after determining whether one of the shooting modes is set, the other is not set by electrical control of the CPU 37. However, the present invention is not limited to this. When the shooting mode is set, the electrical wiring connecting the other setting buttons 27 and 28 and the CPU 37 cannot be disconnected (so that they can be reconnected), or the other setting buttons 27 and 28 cannot be pressed. For example, the other may not be set by mechanical control.

  Further, in the above embodiment, whether or not each shooting mode is set is stored in the form of the flags 45a and 45b provided in the SDRAM 45, but the present invention is not limited to this, but in other forms. You may make it memorize | store in SDRAM45. In addition, the storage medium is not limited to the SDRAM 45, but may be stored in another readable / writable memory.

  In the above embodiment, when one of the shooting modes is set, the other is not set to prevent the macro shooting mode and the quick shooting mode from being set at the same time. However, the present invention is not limited to this, and control may be performed as shown in the flowcharts of FIGS. 7 and 8, for example. Hereinafter, aspects of the flowcharts shown in FIGS. 7 and 8 will be described. In addition, since the structure itself is the same as that of the said embodiment, it abbreviate | omits detailed description by quoting the same code | symbol.

  When the digital camera 2 is set to the macro shooting mode, the macro setting button 27 provided on the back surface of the digital camera 2 is pressed. The CPU 37 that has detected the pressing of the macro setting button 27 accesses the SDRAM 45, checks the quick flag 45b, and determines whether or not the quick shooting mode is set.

  The CPU 37 that has determined that the quick flag 45b is down and the quick shooting mode is not set sets the digital camera 2 to the macro shooting mode, accesses the SDRAM 45, sets the macro flag 45a, and sets the macro shooting mode. Is stored in the SDRAM 45. On the other hand, the CPU 37 that determines that the quick shooting mode 45b is set and the quick shooting mode is already set performs the macro shooting mode setting after canceling the quick shooting mode.

  On the other hand, when the digital camera 2 is set to the quick shooting mode, the quick setting button 28 provided on the back surface of the digital camera 2 is pressed. The CPU 37 that has detected the pressing of the quick setting button 28 accesses the SDRAM 45, checks the macro flag 45a, and determines whether or not the macro shooting mode is set.

  The CPU 37, which has determined that the macro flag 45a is down and the macro shooting mode is not set, sets the digital camera 2 to the quick shooting mode, accesses the SDRAM 45, sets the quick flag 45b, and sets the quick shooting mode. Is stored in the SDRAM 45. On the other hand, the CPU 37 that has determined that the macro shooting mode 45a is set and the macro shooting mode has already been set performs the quick shooting mode setting after canceling the macro shooting mode.

  As in the above-described embodiment, when one shooting mode is set, if the other is not set, a shooting mistake occurs unless the user notices that the selected shooting mode is not set. There is concern. In this example, since one of the set shooting modes is canceled and the other shooting mode instructed is set, it is possible to prevent inconsistency in the operation of the quick shooting mode. The occurrence of shooting mistakes can be suppressed by reflecting the user's operation.

It is a perspective view of the front direction which shows the external appearance of a digital camera. It is a top view of the back direction which shows the external appearance of a digital camera. It is a block diagram which shows the internal structure of a digital camera schematically. It is explanatory drawing which shows an example of a focus evaluation value and the search range in each imaging | photography mode. It is a flowchart which shows the setting operation | movement of macro imaging | photography mode. It is a flowchart which shows the setting operation | movement of quick imaging | photography mode. It is a flowchart which shows the other example of the setting operation | movement of macro imaging | photography mode. It is a flowchart which shows the other example of the setting operation | movement of quick imaging | photography mode.

Explanation of symbols

2 Digital camera 10 Imaging lens 12 Release button 27 Macro setting button (shooting mode setting means)
28 Quick setting button (shooting mode setting means)
32 focus lens 35 lens motor (lens moving means)
37 CPU (focus control means, shooting mode control means)
38 CCD (imaging device)
45 SDRAM (shooting mode control means)
55 AF detection circuit (evaluation value calculation means)

Claims (8)

From the image data, an image pickup device that picks up a subject image that has passed through the image pickup lens and outputs image data corresponding to the subject image, a lens moving unit that moves a focus lens included in the image pickup lens in the optical axis direction, and By extracting a high frequency component, an evaluation value calculating means for calculating a focus evaluation value indicating the level of contrast of the image represented by the image data, and the focus evaluation value of a predetermined search range according to the movement of the focus lens Based on the digital camera equipped with a focusing control means for performing contrast autofocus,
A shooting mode setting means for setting / releasing a plurality of shooting modes including a macro shooting mode that enables close-up shooting and a quick shooting mode that reduces the time required for the autofocus compared to a normal shooting mode;
A digital camera comprising: a shooting mode control means for preventing the macro shooting mode and the quick shooting mode from being set simultaneously.   The digital camera according to claim 1, wherein when one of the macro shooting mode and the quick shooting mode is set, the shooting mode control unit does not set the other.   The shooting mode control means is set when one of the macro shooting mode and the quick shooting mode is set and the other setting is instructed via the shooting mode setting means. 2. The digital camera according to claim 1, wherein one of the photographing modes is canceled and the other photographing mode instructed is set. Has a two-stage release button consisting of half-press and full-press,
4. The digital camera according to claim 1, wherein the focusing control unit performs the autofocus in response to the release button being pressed halfway. 5.   5. The quick shooting mode according to claim 1, wherein the time required for the autofocus is shortened by reducing the search range closer to the side than the normal shooting mode. 6. Digital camera. From the image data, an image pickup device that picks up a subject image that has passed through the image pickup lens and outputs image data corresponding to the subject image, a lens moving unit that moves a focus lens included in the image pickup lens in the optical axis direction, and By extracting a high frequency component, an evaluation value calculating means for calculating a focus evaluation value indicating the level of contrast of the image represented by the image data, and the focus evaluation value of a predetermined search range according to the movement of the focus lens A focusing control means that performs contrast-based autofocus, a macro shooting mode that enables close-up shooting, and a quick shooting mode that reduces the time required for autofocusing compared to the normal shooting mode. In a shooting mode setting method for a digital camera having a plurality of shooting modes including:
A shooting mode setting method that prevents the macro shooting mode and the quick shooting mode from being set simultaneously.   7. The shooting mode setting method according to claim 6, wherein when one of the macro shooting mode and the quick shooting mode is set, the other is not set. When one of the macro shooting mode and the quick shooting mode is set and the other setting is instructed, the one shooting mode that has been instructed is canceled by canceling the set one shooting mode. 7. The shooting mode setting method according to claim 6, wherein the mode is set.

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