JP2005328225A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera in which an enlarged screen is displayed at an appropriate timing. <P>SOLUTION: Half-push operation of a shutter button at an operating section 106 is detected at S1, and focus is locked to an object at a photography position indicated by an auto-focus frame AF in response to that detection at S2. An underwater judging section 123 detects the value of a water pressure sensor 121 and judges whether a digital camera 10 exists currently underwater or not based on that value at S3. When it exists underwater, transition is made to S4 where the enlarged image M of a focus area R, i.e. a part of the object surrounded by the auto-focus frame AF, is compounded with a through image and displayed on a monitor 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital camera, and more particularly to a digital camera used for underwater photography.

Conventionally, various techniques for facilitating confirmation of focusing in a digital camera used underwater have been devised. For example, according to Patent Document 1, the focus determination circuit determines the contrast of the image captured by the image sensor, and determines the focus point. The image around the subject within the focusing point is enlarged and displayed on the LCD.
JP 2003-234940 A, paragraph 0016

  By the way, in patent document 1, as a display method of an enlarged screen, when a dedicated display changeover switch is turned ON, a configuration for switching to an enlarged screen, a configuration for switching display every predetermined time, and a main screen and an enlarged screen as one LCD The structure which displays simultaneously on the top is disclosed. However, providing a dedicated switch may increase the manufacturing cost of the digital camera. Further, the configuration in which the display is switched every predetermined time is disadvantageous because there is a possibility that the timing at which the enlarged image is desired to be viewed does not match the timing at which the enlarged image is displayed. Furthermore, in the configuration in which the main screen and the enlarged screen are displayed at the same time, there is a possibility that an enlarged image is displayed at a timing when only the main screen is desired. The present invention has been made in view of such problems, and an object thereof is to provide a digital camera that displays an enlarged screen at an appropriate timing.

  In order to solve the above problem, the invention according to claim 1 performs autofocus adjustment when the shutter button is half-pressed, and locks the focus after the autofocus adjustment when the half-pressed state of the shutter button is maintained. In the digital camera, a display unit for displaying a subject image, a detection unit for detecting that the shooting environment is underwater, and maintaining the half-pressed state of the shutter button and focusing on the locked focus according to the detection There is provided a digital camera comprising display control means for enlarging and displaying a focus area which is a part of a subject image surrounded by a frame having a predetermined size.

  According to the present invention, the focus area is enlarged and displayed according to the half-pressed state of the shutter button and the detection that the shooting environment is underwater. That is, unlike the prior art, a part of the subject image whose focus is locked can be enlarged and displayed without providing a special button and at an appropriate timing.

  According to a second aspect of the present invention, there is provided the digital camera according to the first aspect, wherein the display control means displays a distance to a subject whose focus is locked.

  According to a third aspect of the present invention, there is provided the digital camera according to the first or second aspect, wherein the display control means terminates the enlarged display when it is no longer detected that the photographing environment is underwater.

  According to the present invention, it is possible to prevent the display of the subject image from being hindered by unnecessary enlarged display on land where the digital camera is easily operated.

  According to a fourth aspect of the present invention, there is provided the digital camera according to the first or second aspect, wherein the display control means terminates the enlarged display when the half-pressed state is released.

  According to the present invention, even when the focus lock of the subject is released by releasing the shutter button halfway, it is possible to prevent the enlarged image from being displayed and hindering the display of the subject image.

  The invention according to claim 5 further includes moving means for receiving movement of the frame, and the display control means enlarges and displays the focus area at the center of the display means. Provide digital cameras.

  According to the present invention, it is possible to prevent the enlarged image from being displayed outside the display device by displaying the focus area in the central portion in an enlarged manner regardless of the moving position of the frame.

  According to the present invention, the focus area is enlarged and displayed according to the half-pressed state of the shutter button and the detection that the shooting environment is underwater. That is, unlike the prior art, a part of the subject image whose focus is locked can be enlarged and displayed without providing a special button and at an appropriate timing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[Schematic configuration]
FIG. 1 is a block diagram showing a schematic configuration inside a digital camera 10 according to a preferred embodiment of the present invention. In the figure, a CPU 100 is a control unit that performs overall control of each circuit of the camera system, and includes storage means such as a ROM 102 and a RAM 104. The ROM 102 stores programs processed by the CPU 100 and various data necessary for control. The RAM 104 is used as a work area when the CPU 100 performs various arithmetic processes. The ROM 102 is composed of a flash ROM capable of erasing / writing data. The CPU 100 outputs an operation signal output from the operation unit 106 including a release button, a power button, a strobe button, a macro button, a zoom lever, a display button, a BACK button, a mark button, a menu / OK button, a cross button, a mode switch, and the like. Based on this, the operation of the corresponding circuit is controlled, and lens drive control, shooting operation control, image processing control, image data recording / reproduction control, display control of the monitor 30, etc., automatic exposure (AE) calculation, automatic focus adjustment are performed. Various calculation processes such as (AF) calculation and white balance (WB) adjustment calculation are executed.

  The light that has passed through the lens 14 enters a CCD image sensor (CCD) 108. Photosensors are arranged in a plane on the light receiving surface of the CCD 108, and an optical image of a subject formed on the light receiving surface of the CCD 108 via the lens 14 is a signal corresponding to the amount of incident light by each photosensor. Converted to electric charge. The signal charge accumulated in each photosensor is sequentially read out as a voltage signal (image signal) corresponding to the signal charge based on a driving pulse given from a timing generator (not shown) and sent to the analog signal processing unit 110.

  The analog signal processing unit 110 includes a signal processing circuit such as a sampling hold circuit, a color separation circuit, a gain adjustment circuit, an A / D converter, and the image signal input by the analog signal processing unit 110 is correlated double sampling. Processing and color separation processing are performed on each of the R, G, and B color signals, and signal level adjustment (pre-white balance processing) of each color signal is performed. Then, it is converted into a digital image signal and stored in the RAM 104.

  The image signal stored in the RAM 104 is sent to the image signal processing unit 112. The image signal processing unit 112 includes a digital signal processor (DSP) including a luminance / color difference signal generation circuit, a gamma correction circuit, a sharpness correction circuit, a contrast correction circuit, a white balance correction circuit, and the like, and is input according to a command from the CPU 100. The processed image signal is processed. The image signal input to the image signal processing unit 112 is converted into a luminance signal (Y signal) and a color difference signal (Cr, Cb signal) and subjected to predetermined processing such as gamma correction and then stored in the RAM 104. Stored. The image data stored in the RAM 104 is input to the display unit 114. The display unit 114 converts the input image data into a predetermined signal for display (for example, an NTSC color composite video signal) and outputs the signal to the monitor 30.

  The image data in the RAM 104 is periodically rewritten by the image signal output from the CCD 108, and the image signal generated from the image data is supplied to the monitor 30, so that the image input via the CCD 108 is real-time. It is displayed on the monitor 30. The photographer can confirm the shooting angle of view from the image (through image) displayed on the monitor 30.

  The display unit 114 includes an OSD signal generation circuit, and the OSD signal generation circuit displays character and symbol information such as a shutter speed, an aperture value, the number of images that can be captured, a shooting date and time, and a warning message according to a command from the CPU 100. Generate a signal. A signal output from the OSD signal generation circuit is mixed with an image signal as necessary and supplied to the monitor 30. As a result, a combined image in which characters and the like are combined with the through image and the reproduced image is displayed.

  When the mode of the camera is set to the shooting mode by the mode switch, the digital camera 10 can perform shooting. When the release button is half-pressed in this state, an S1 ON signal is issued to the CPU 100. The CPU 100 detects this S1 ON signal and executes AE and AF operations. That is, the CPU 100 controls a lens driving unit (not shown) so that the subject is in focus, measures the brightness of the subject, and determines the aperture value and the shutter speed so as to achieve proper exposure.

  Thereafter, when the release button is fully pressed, an S2 ON signal is issued to the CPU 100, and the CPU 100 detects the S2 ON signal and executes a recording operation. In other words, an aperture drive unit (not shown) and the electronic shutter of the CCD 108 are controlled so that the aperture value and shutter speed determined when the release button is half-pressed, and the image is captured.

  In this way, in response to the full pressing operation of the release button, capturing of image data for recording is started, and an image signal for one frame output from the CCD 108 is captured into the RAM 104 via the analog signal processing unit 110. The image signal taken into the RAM 104 is subjected to predetermined signal processing by the image signal processing unit 112, stored again in the RAM 104, and sent to the image recording unit 116.

  The image recording unit 116 includes a compression / decompression processing circuit, and the compression / decompression processing circuit compresses image data input according to a command from the CPU 100 according to JPEG or another predetermined format. The compressed image data is recorded on the recording medium 120 as an image file of a predetermined format via a media interface (media I / F) 118. The recording medium 120 is a removable medium that can be attached to and detached from the camera body, such as an xD picture card, smart media, compact flash, magnetic disk, optical disk, magneto-optical disk, memory stick, etc. It may be a recording medium (internal memory).

  When the playback mode is selected with the mode switch, the image recorded on the recording medium 120 can be played back. When the mode switch is set to the playback mode, the image data of the image file recorded last on the recording medium 120 is read. The read image data is output to the monitor 30 via the display unit 114 after being subjected to a required expansion process in the image recording unit 116. Thereby, browsing of the image recorded on the recording medium 120 becomes possible.

  The frame advance of the image is performed with the cross button. When the right key of the cross button is pressed, the next image file is read from the recording medium 120 and reproduced and displayed on the monitor 30. When the left key of the cross button is pressed, the previous image file is read from the recording medium 120 and reproduced and displayed on the monitor 30.

  The digital camera 10 shifts its operation mode to the communication mode with the USB connection to the host device as a trigger. The communication mode is “PC mode” connected to a personal computer (PC) and recognized as a removable disk (mass storage device) from the PC, connected to the printer, and recorded on the recording medium 120 with respect to the printer. "Direct print mode" to print the image that is present. The communication control unit 122 transmits and receives data according to a predetermined command format under the set communication mode.

  The digital camera body 10 is waterproofed by being housed in the underwater housing 11 and can be photographed underwater. A water pressure sensor 121 is provided in the underwater housing 11 and detects the water pressure applied to the underwater housing 11. The underwater determination unit 123 detects the value of the water pressure sensor 121 and determines whether or not the digital camera 10 is currently in water based on this value. As an example, the underwater determination unit 123 determines that it is in water when the water pressure exceeds 1.2 atmospheres, that is, when the digital camera 10 is at a depth of about 2 m. On the other hand, when the water pressure is 1.2 atm or less, the underwater determination unit 123 determines that it is not in water (that is, on land). Instead of the water pressure sensor 121, various devices (such as a submersion sensor) that can detect that the digital camera 10 is in water may be provided.

[Processes performed by the digital camera]
Next, processing executed by the digital camera 10 will be described based on the flowchart of FIG. In this process, when the shooting environment is underwater when the focus is locked, a part of the focused subject is enlarged and displayed.

  In S1, a half-press operation of the shutter button of the operation unit 106 is detected, and in S2, focus lock (that is, focus lock) is performed on the subject at the shooting position indicated by the autofocus frame AF in response to this detection. FIG. 3A shows a display example of a through image and an autofocus frame AF when the focus is locked. In this figure, a half-press operation is performed in a state where the focus F, which is the center of the autofocus frame AF, is located on a part of the subject, and the autofocus frame AF surrounds a part of the subject. Note that the display position of the autofocus frame AF on the monitor 30 may be the center of the monitor 30, or by scrolling up, down, left and right with the cross button (for example, the monitor 30 as shown in FIG. 3A). It may be possible to move to a position slightly moved to the upper left of the center of. Then, the focus may be locked to the subject at the shooting position indicated by the moved autofocus frame AF by pressing the shutter button halfway thereafter. In S <b> 3, the water pressure sensor 121 detects the water pressure applied to the underwater housing 11. The underwater determination unit 123 detects the value of the water pressure sensor 121 and determines whether or not the digital camera 10 is currently in water based on this value. If it is underwater, the process proceeds to S4, and if it is not underwater, this process is terminated. After this process is completed, it is possible to continue waiting for detection of the shutter button full press and to record an image in response to the full press detection.

  In S4, the enlarged image M, which is an image obtained by enlarging the focus area R, which is a partial area of the subject surrounded by the autofocus frame AF, is combined with the through image and enlarged and displayed on the monitor 30. The enlarged display of the focus area R is performed as follows, for example. That is, as shown in FIG. 4, an enlarged image M, which is an image of 320 × 120 pixels corresponding to the portion surrounded by the autofocus frame AF, is cut out from an image input via the CCD 108 and converted into a through image of 640 × 240 pixels. Combine and display. FIG. 3B shows a display example of the enlarged image M. The enlarged image M is an image cut out from the CCD 108. However, if the cut-out size fits within the maximum display size of the monitor 30, it can be combined with the through image without being thinned out. In this case, since the image quality deterioration due to thinning does not occur in the enlarged image M, the details of the subject can be visually observed. The display position of the enlarged image M is the central portion of the monitor 30 regardless of the position of the autofocus frame AF when the focus is locked in order to prevent a part or all of the enlarged image M from protruding from the monitor 30 and being displayed. Is preferably displayed. As shown in FIG. 3C, the subject at the shooting position may be displayed with the distance to the subject when the focus is locked. Various methods can be used to calculate the distance to the subject. For example, the distance to the subject may be calculated from the positional relationship of the focus lens when the focus is locked, or various distance measurement such as triangular distance measurement is performed with the digital camera 10. May be.

  In S5, it is determined whether a half-press release operation of the shutter button of the operation unit 106 is detected. If the half-press is released, the process proceeds to S7. If the half-press is not released, that is, if the half-press is maintained, the process proceeds to S6. In S <b> 6, the water pressure sensor 121 detects the water pressure applied to the underwater housing 11. The underwater determination unit 123 detects the value of the water pressure sensor 121 and determines whether or not the digital camera 10 is currently in water based on this value. If it is in the water, this process is terminated. If it is not in the water, that is, if it is on land, the process proceeds to S7. In S <b> 7, the combined display of the enlarged image M is finished, and only the through image is displayed on the monitor 30. A program for causing the CPU 100 to execute the above-described processing steps S1 to S7 is stored in the ROM 102.

  Through the above processing, during underwater shooting, since the enlarged image M of the focus area R, which is the part where the autofocus frame AF surrounds the subject image, is displayed, the details of the focus area R can be visually confirmed, and the focus locked subject It is possible to easily determine whether or not the subject is in focus. At this time, since the distance to the subject is also displayed, the distance to the subject can be grasped.

1 is a block diagram of a digital camera according to a preferred embodiment of the present invention. Flow chart showing the flow of processing executed by the digital camera The figure which shows the example of a display of a through image and an enlarged image Enlarged image concept illustration

Explanation of symbols

10: Digital camera, 121: Water pressure sensor, 122: Underwater determination unit

Claims (5)

In a digital camera that performs autofocus adjustment when the shutter button is half-pressed, and locks the focus after the autofocus adjustment when the shutter button is half-pressed,
Display means for displaying a subject image;
Detection means for detecting that the shooting environment is underwater;
Display control for enlarging and displaying a focus area that is a part of a subject image surrounded by a frame of a predetermined size centered on the locked focus in accordance with the half-pressed state of the shutter button and the detection. Means,
Digital camera equipped with.   The digital camera according to claim 1, wherein the display control unit displays a distance to a subject whose focus is locked.   The digital camera according to claim 1, wherein the display control unit terminates the enlarged display when it is no longer detected that the shooting environment is underwater.   The digital camera according to claim 1, wherein the display control unit terminates the enlarged display in response to the release of the half-pressed state. A moving means for receiving movement of the frame;
The digital camera according to any one of claims 1 to 4, wherein the display control means enlarges and displays the focus area at a central portion of the display means.

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