Abstract:
In an imaging apparatus capable of continuously capturing images, the captured images are displayed sequentially to allow a user to select a desired image and record the selected image on a recording medium. This can prevent the recording of unnecessary images on the recording medium, making effective use of the memory space.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-089513, filed on Mar. 25, 2005, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an imaging apparatus such as a digital camera and an image recording method for the imaging apparatus.  
         [0004]     2. Description of the Related Art  
         [0005]     An imaging apparatus for forming a subject image on an image-pickup device such as a CCD through an imaging optical system, converting it to an electric signal, and recording a resulting subject image on a recording medium such as a semiconductor memory have recently become widespread.  
         [0006]     A camera with a so-called precapture function is proposed in Japanese Patent Laid-Open No. 2002-252804. In this camera, a buffer memory is circularly used to store a predetermined number of the most recently captured images while a user remains pressing a shutter release button at a first (half-press) position, allowing the user to capture images sequentially. Then, when the user further presses the shutter release button to a second (full-press) position, the images stored in the buffer memory before the press of the shutter release button to the second position and an image shot at the time of pressing the shutter release button to the second position are recorded on a recording medium.  
         [0007]     The use of this precapture function allows the user to get a desired image easily without missing the opportunity to get the best shot.  
         [0008]     In the case of the precapture function proposed in Japanese Patent Laid-Open No. 2002-252804, the images stored in the buffer memory before the press of the shutter release button to the second position and the image shot at the time of the press of the shutter release button to the second position are all recorded on the recording medium. This results in recording even images that do not need recording.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     According to the present invention, there is provided an imaging apparatus capable of continuously capturing images, in which the images continuously captured are displayed sequentially to allow a user to select a desired image and record the selected image on a recording medium. In this case, only the image selected by the user is recorded on the recording medium, and this makes effective use of the memory space possible.  
         [0010]     The following is an example of a more detailed structure. An imaging apparatus comprises: an imaging unit for performing an imaging operation to capture a subject image; a recording medium for recording the image captured in the imaging operation performed by the imaging unit; a display part for displaying the image captured in the imaging operation performed with the imaging unit; an imaging instruction part for outputting a first instruction signal when depressed to a first position and a second instruction signal when depressed to a second position; a selection instruction part for outputting a selection instruction signal; and a controller. In the imaging apparatus, the controller controls the imaging unit to repeatedly perform the imaging operation in response to the first instruction signal. Then, when the second instruction signal is output while the imaging operation is repeated, at least images captured before the output of the second instruction signal are displayed sequentially on the display part. Then, when the selection instruction signal is output while the images are sequentially displayed on the display part, an image being displayed on the display part at the time of outputting the selection instruction signal is recorded on the recording medium.  
         [0011]     In addition to the above-mentioned recording medium, another recording medium (first recording medium) for temporary storage of images continuously captured by the imaging unit under the control of the controller can also be provided. In this case, another recording medium exists in the imaging apparatus as well as the recording medium (second recording medium) for recording the image being displayed on the display part in response to the selection instruction signal.  
         [0012]     When the selection instruction signal is output, the controller can copy the image, being displayed at the time of outputting the election instruction signal, from the first recording medium to the second recording medium so that the image will be recorded on the second recording medium. This allows only the necessary image can be copied from the first recording medium to the second recording medium so that only the necessary image will be recorded on the second recording medium.  
         [0013]     For example, the first recording medium can be a hard disk drive. The second recording medium can be a recording medium removably loaded into the imaging apparatus.  
         [0014]     The selection instruction part can also output the selection instruction signal in response to the operation of an operation part. Alternatively, it can output the selection instruction signal according to biometric information of an operator (user using this imaging apparatus). The biometric information of the operator can include the brain wave patterns, voice, and eye blinks of the operator.  
         [0015]     Further, the controller can display the images captured by the imaging unit on the display part in response to the second instruction signal while extending the display duration of the images irrespective of the actual capturing time of the images. This makes it easy for the user to select an image.  
         [0016]     The present invention can also be understood as another example of an imaging apparatus. The imaging apparatus comprises: an imaging part for performing an imaging operation to capture a subject image so as to acquire image data; a display part for displaying the image based on the image data; an operation part manually operated to output a first instruction signal, a second instruction signal, or a third instruction signal; and a controller. In the imaging apparatus, the controller controls the imaging part to acquire image data corresponding to a plurality of images in response to the first instruction signal, displays the plurality of images sequentially on the display part in response to the second instruction signal, and selects image data to be recorded in response to the third instruction signal.  
         [0017]     The imaging apparatus can include a first recording medium for temporary storage of the plural pieces of image data and a second recording medium for recording the image data selected.  
         [0018]     The imaging apparatus can also include a release button and an operation button. In this case, the release button can be manually operated to output the first instruction signal when depressed to a first position and the second instruction signal when depressed to a second position. The operation button can be manually operated to output the third instruction signal.  
         [0019]     In this case, the third instruction signal can be output according to biometric information of an operator (user using the imaging apparatus). The biometric information of the operator can include, for example, the brain wave patterns, voice, and eye blinks of the operator.  
         [0020]     The controller can also display the images captured by the imaging part in response to the second instruction signal while extending the display duration of the images irrespective of the actual capturing time of the images. This makes it easy for the user to select an image.  
         [0021]     In a more specific structure of the present invention, an imaging apparatus comprises: an image pickup device for capturing a subject image to output an image signal; an image processing controller for processing the image signal to generate image data; a monitor capable of displaying the image data; first, second, and third switches manually operated to output first, second, and third instruction signals, respectively; and a microcomputer. In the imaging apparatus, the microcomputer repeatedly operates the image pickup device and the image processing controller in response to the first instruction signal, displays images captured at least before and at the time of outputting the second instruction signal on the monitor in response to the second instruction signal, and records image data, being displayed at the time of outputting the third instruction signal, on a recording medium in response to the third instruction signal.  
         [0022]     On the other hand, the present invention can also be directed to an image recording method.  
         [0023]     According to the present invention, only necessary images among all images obtained by a precapture function can be recorded, thereby providing an imaging apparatus and an image recording method for the imaging apparatus capable of effective use of recording medium each having a limited capacity. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0024]     These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:  
         [0025]      FIG. 1  is a block diagram showing the details of an internal electric circuit configuration of a digital camera as an example of an imaging apparatus according to a first embodiment of the present invention;  
         [0026]      FIG. 2  is a back view of the appearance of the digital camera for explaining operation parts of the camera;  
         [0027]      FIG. 3  is a flowchart showing the operation of the digital camera in a single-shot mode;  
         [0028]      FIG. 4  is a block diagram showing the details of an internal electric circuit configuration of a digital camera as an example of an imaging apparatus according to a second embodiment of the present invention;  
         [0029]      FIG. 5  is an illustration showing such a state that the digital camera is connected to an electroencephalographic device as an example of a biometric information input device;  
         [0030]      FIG. 6  is an illustration showing such a state that the electroencephalographic device is attached to a user; and  
         [0031]      FIG. 7  is a flowchart showing the operation of the digital camera in a single-shot mode according to the second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     Preferred embodiments of the invention are described below with reference to the accompanying drawings.  
       First Embodiment  
       [0033]      FIG. 1  is a block diagram showing the details of an internal electric circuit configuration of a digital camera as an example of an imaging apparatus according to a first embodiment of the present invention. It is assumed in  FIG. 1  that the digital camera (hereinafter called the “camera”) shown in  FIG. 1  is a digital single-lens reflex (SLR) camera with interchangeable lenses. However, the first embodiment can be applied to cameras other than the SLR camera.  
         [0034]     The camera  1  shown in  FIG. 1  has a lens barrel  100  and a camera body  200 .  
         [0035]     A lens control microcomputer (hereinafter called “Lucom”)  101  controls each component of the lens barrel  100 . On the other hand, a body control microcomputer (hereinafter called “Bucom”)  201  controls each component of the camera body  200 . When the lens barrel  100  is mounted on the camera body  200 , the Lucom  101  and the Bucom  201  are electrically connected through a communication connector  101   a  so that they can communicate with each other. In this case, the Lucom  101  cooperates dependently with the Bucom  201  to operate in the camera system.  
         [0036]     An imaging optical system  102  is provided inside the lens barrel  100 . The imaging optical system  102  consists of a plurality of optical lenses, and is driven along its optical axis by a DC motor (not shown) provided in a lens drive mechanism  103 .  
         [0037]     An aperture  104  is provided behind the imaging optical system  102 . The aperture  104  is driven to be opened or closed by a stepping motor (not shown) provided in an aperture drive mechanism  105 . The opening/closing of the aperture  104  is controlled to control the amount of light coming from a subject through the imaging optical system  102  and incident into the camera body  200 .  
         [0038]     Here, the Lucom  101  controls the DC motor in the lens drive mechanism  103  and the stepping motor in the aperture drive mechanism  105  in accordance with instructions from the Bucom  201 .  
         [0039]     An AF mirror  202  is arranged inside the camera body  200  on the optical path of the imaging optical system  102 . When the camera  1  is in a normal state, the AF mirror  202  is at the position shown in  FIG. 1 . In this case, a flux of light coming from a subject through the imaging optical system  102  is incident on and reflected by the AF mirror  202 . The flux of light reflected by the AF mirror  202  is guided to an AF sensor unit  203  for automatic focus adjustment (autofocus (AF) processing). An AF sensor for AF processing, for example, of a phase-contrast type, is provided inside the AF sensor unit  203 . The flux of light incident on the AF sensor is converted to an electric signal. The output of the AF sensor in the AF sensor unit  203  is sent to the Bucom  201  through an AF sensor drive circuit  204 . The Bucom  201  performs distance measurement processing to calculate a focus state of the imaging optical system  102 . The Bucom  201  sends the calculation result to the Lucom  101 . Then, based on the focus state notified from the Bucom  201 , the Lucom  101  controls the drive of the imaging optical system  102 .  
         [0040]     When the camera  1  is changed to an imaging mode, the AF mirror  202  is withdrawn out of the optical axis of the imaging optical system  102 , and moved to a predetermined position. A mirror drive mechanism  205  drives the AF mirror  202  to move this way. Further, the Bucom  201  controls the mirror drive mechanism  205 .  
         [0041]     In this case, since the AF mirror  202  is withdrawn out of the optical path of the imaging optical system  102 , the flux of light coming from the subject through the imaging optical system  102  is incident on a shutter  206 . The shutter  206  is of a focal plane type consisting of front and rear curtains. A shutter charge mechanism  207  charges a spring to drive the front and rear curtains. A shutter control circuit  208  controls the drive of the front and rear curtains. The shutter charge mechanism  207  and the shutter control circuit  208  are controlled by the Bucom  201 .  
         [0042]     The flux of light passing through the shutter  206  is incident on an image pickup device  210  in an imaging unit  209  arranged behind the shutter  206 . The image pickup device  210  is protected by a dust reduction filter  211  provided between the image pickup device  210  and the imaging optical system  102 . The dust reduction filter  211  is made of a transparent material such as glass.  
         [0043]     Further, a piezoelectric element  212  is attached along the circumference of the dust reduction filter  211  to vibrate the dust reduction filter  211  at a predetermined frequency. The piezoelectric element  212  has two electrodes and is driven by a dust-reduction (DR) filter driving circuit  213 . The dust reduction filter  211  is controlled by the Bucom  201 . In other words, the DR filter driving circuit  213  drives the piezoelectric element  212  to vibrate the dust reduction filter  211 . This allows dust particles adhering on the surface of the dust reduction filter  211  to be shaken off.  
         [0044]     Here, the image pickup device  210  and the piezoelectric element  212  are integrally housed in a case with the dust reduction filter  211  as its one side. This construction can ensure the prevention of the dust particles from adhering to the image pickup device  210 .  
         [0045]     Further, a thermometric circuit  214  is provided near the imaging unit  209 . In general, temperature affects the elastic coefficient of a glass material. In other words, since temperature is one factor that varies the natural frequency of the dust reduction filter  211 , ambient temperature is always measured for vibrating the dust reduction filter  211 . It is preferable that the temperature measuring points of the thermometric circuit  214  be set very close to both poles of the vibrating surface of the dust reduction filter  211 . The control of vibration of the dust reduction filter  211  in consideration of temperature variations allows the dust reduction filter  211  to be always vibrated under the optimum conditions.  
         [0046]     Here, the camera  1  shown in  FIG. 1  uses an electronic view finder (EVF) as its finder. Therefore, an electric signal (picture signal) obtained from the image pickup device  210  is read through an imaging interface (I/F) circuit  215  at every predetermined interval, and converted to a digital signal. Image data obtained from the digital signal from the imaging I/F circuit  215  is stored in a buffer memory  217  such as an SDRAM through an image processing controller  216 . The buffer memory  217  is a memory for temporary storage of data such as image data, and is used as a work area for various processing of image data.  
         [0047]     The image data read through the imaging I/F circuit  215  and stored in the buffer memory  217  is read by the image processing controller  216 . The image data read by the image processing controller  216  is subjected to image processing such as white balance correction for EVF display, and stored in the buffer memory  217 . After that, the image data stored in the buffer memory  217  is read by the image processing controller  216  on a frame basis, and converted to a video signal. The video signal is resized to fit a predetermined display size, and displayed on an EVF-LCD monitor  218  as a monitor image so that a user can view the image on the EVF-LCD monitor  218  through an eyepiece  219 . This allows the user to observe a subject state through his or her eye even without the provision of an optical finder.  
         [0048]     After completion of the imaging operation, the shot image can also be displayed on an external LCD monitor  220 . In other words, the image data read from the imaging I/F circuit  215  and stored in the buffer memory  217  is read by the image processing controller  216 . The image data read by the image processing controller  216  is subjected to known image processing such as white balance correction, gray-level correction, color correction, etc, and stored in the buffer memory  217 . After that, the image data stored in the buffer memory  217  is read by the image processing controller  216 , in which the image data is converted to a video signal, resized to fit a predetermined display size, and output to and displayed on the external LCD monitor  220 . This allows the user to view the image displayed on the external LCD monitor  220 , and hence to check the shot image.  
         [0049]     Upon image recording, the image data processed by the image processing controller  216  is compressed by a known compression technique such as JPEG. The JPEG data obtained by applying JPEG compression to the image data is stored in the buffer memory  217 , recorded on an internal recording medium  221  as a first recording medium, and then recorded on a removable recording medium  222  as a second recording medium. The internal recording medium  221  is, for example, a hard disk drive. On the other hand, the removable recording medium  222  can be a memory card removably loaded into the camera  1 .  
         [0050]     Further, upon image playback, the image processing controller  216  reads and decompresses the JPEG data recorded on the internal recording medium  221  or the removable recording medium  222 . The decompressed data is converted to a video signal, resized to a predetermined display size, and output to the external LCD monitor  220  so that it will be displayed on the external LCD monitor  220 .  
         [0051]     A nonvolatile memory  223  storing predetermined control parameters necessary for camera control and a Flash ROM  224  with a camera control program written to it are also connected to the Bucom  201  so that the Bucom  201  can access the control parameters and the camera control program. The nonvolatile memory  223  is, for example, a rewritable EEPROM.  
         [0052]     Further, a battery  226  as an electric power source is connected to the Bucom  201  through a power supply circuit  225 . The power supply circuit  225  converts the voltage of the battery  226  to a voltage necessary for each component of the camera system, and supplies the voltage to each component of the camera system.  
         [0053]     In addition, an LCD panel  227  for showing the operating conditions of the camera  1  so that the user can check the operating conditions of the camera  1  on the display, and camera control switches (SW)  228  for detecting the various operating conditions of the camera  1  are connected to the Bucom  201 .  
         [0054]     The following describes operation parts of the camera  1 .  FIG. 2  is a back view of the appearance of the camera  1  for explaining the operation parts of the camera  1 . In an actual situation, more operation parts than those shown in  FIG. 2  can be arranged on the back face of the camera  1 .  
         [0055]     As shown in  FIG. 2 , a main dial  311 , an AF frame button  312 , an AE lock button  313 , a playback mode button  314 , an erase button  315 , a protect button  316 , an information display button  317 , a menu button  318 , a cross-shaped cursor button  319 , an OK button  320 , and a bookmark button  321  are provided on the back face of the camera  1 . Further, a shutter release button  322  is provided on the top face of the camera  1 .  
         [0056]     The user operates the main dial  311  while pressing any other operation part. The user can rotate the main dial  311  to change the setting of a function related to the operation part being pressed by the user at the time.  
         [0057]     The AF frame button  312  is to select an AF system for imaging. When the user rotates the main dial  311  while pressing this AF frame button  312 , the AF system can be changed, for example, to multi AF or spot AF. In the multi AF mode, the focusing states of multiple focusing points on a screen are detected. On the other hand, in the spot AF mode, the focusing state of one point (selectable among multiple points) on the screen is detected.  
         [0058]     The AE lock button  313  is to lock exposure. While the user is pressing the AE lock button  313 , the amount of exposure calculated at the time is locked.  
         [0059]     The playback mode button  314  is to switch the operation mode of the camera  1  to a playback mode capable of playing images back.  
         [0060]     The erase button  315  is to erase image data (JPEG file) in the playback mode from the internal recording medium  221  or the removable recording medium  222 .  
         [0061]     The protect button  316  is to protect image data in the playback mode from being erased by accident.  
         [0062]     The information display button  317  is to display additional information embedded in image data based on image information (e.g. Exif information).  
         [0063]     The menu button  318  is to display a menu screen on the external LCD monitor  220 . The menu screen consists of menu items in a multi-layered structure. The user or operator can select a desired menu item using the cross-shaped cursor button  319  and confirm the selected item by pressing the OK button  320 . The menu items include, for example, an imaging menu, a playback menu, a custom menu, and a setup menu. On the imaging menu, the setup of the internal recording medium  221  or the removable recording medium  222 , and the settings of image data quality, image processing, and a scene mode can be configured. On the playback menu, playback conditions upon image playback and the setting upon printing of images can be configured. On the custom menu, various detailed settings can be customized according to user&#39;s preferences. On the setup menu, the operational conditions of the camera such as the kind of alarm beep sound can be set.  
         [0064]     The bookmark button  321  as a selection instruction part is to output a selection instruction signal for selecting an image, from images recorded in a capture operation to be described later, as being copied from the internal recording medium  221  to the removable recording medium  222 .  
         [0065]     The shutter release button  322  as an imaging instruction part is to perform imaging preparation and exposure operations. The shutter release button consists. of two-step switches, namely a first shutter release switch and a second shutter release switch. When the user presses the shutter release button  322  to a first position, the first shutter release switch works to output a first instruction signal upon which the imaging preparation operations, such as photometering and distance measuring, and the capture operation to be described later are performed. When the user further presses the shutter release button  322  to a second position, the second shutter release switch works to output a second instruction signal upon which images captured at least before and at the time of outputting the second instruction signal are all record on the internal recording medium  221 .  
         [0066]     Referring next to the flowchart of  FIG. 3 , an image recording method performed by the camera  1  having the above-mentioned structure is described.  FIG. 3  is a flowchart showing the operation of the camera  1  in a single-shot mode. The flow of  FIG. 3  is controlled by the Bucom  201  as a controller.  
         [0067]     When the camera  1  is in the single-shot mode, the flow of the flowchart of  FIG. 3  is started each time the user presses the shutter release button  322  to the first position. When the user presses the shutter release button  322  to the first position, distance measuring is performed to calculate the focus state of the imaging optical system  102  (step S 1 ). Then, the Lucom  101  calculates the amount of driving the imaging optical system  102  necessary for focus adjustment according to the focus state. Then, based on the calculated amount of drive, the imaging optical system  102  is driven (step S 2 ).  
         [0068]     Then, the AF mirror  202  is moved to the predetermined position where it is withdrawn out of the optical path of the imaging optical system  102 , and the shutter  206  is opened (step S 3 ). This exposes the imaging surface of the image pickup device  210 , enabling the capture operation (step S 4 ). In this capture operation, continuous images are captured. The sequence of images (hereinafter called captured images) obtained in the capture operation are stored one by one in the buffer memory  217 . The buffer memory  217  can store a predetermined number of frames (for example, 10 frames) at the maximum. When a new image is captured, if the buffer  217  already contains the predetermined number of image frames, the oldest image is overwritten with the new image in due order. Thus, the predetermined number of frames corresponding to the latest images are stored in the buffer memory  217 . If the number of shot images is less than the predetermined number of frames when the capture operation shifts to the following operation (step S 6 ), all the shot images are, of course, stored in the buffer memory  217 .  
         [0069]     During the capture operation, photometering is performed from cumulatively added values of data in a predetermined range of the image each time one frame is captured. According to the photometering result, the amount of opening of the aperture  104  or the like is adjusted. Alternatively, distance measuring can be performed from cumulatively added values of data in the predetermined range of the image to finely adjust the position of the imaging optical system  102  according to the distance measuring result.  
         [0070]     During the capture operation, it is determined whether the user presses the shutter release button  322  to the second position (step S 5 ). As a result of determination in step S 5 , if the user does not press the shutter release button  322  to the second position, the procedure returns to step S 4  to continue the capture operation.  
         [0071]     On the other hand, it is determined in step S 5  that the user has pressed the shutter release button  322  to the second position, the procedure proceeds from step S 5  to step S 6 , to record, on the internal recording medium  221 , the predetermined number of frames corresponding to the latest captured images including the image captured when the user pressed the shutter release button  322  to the second position (step S 6 ). Upon image recording in step S 6 , the capture operation can be continued for a predetermined period of time after the shutter release button  322  is pressed to the second position so that a predetermined number of frames corresponding to the latest captured images obtained during the period after the shutter release button  322  is pressed to the second position will also be recorded on the internal recording medium  221  as part of the captured images.  
         [0072]     After completion of image recording in step S 6 , the captured images recorded on the internal recording medium  221  are read and played back frame by frame (step S 7 ). Upon playback in step S 7 , the images are played back frame by frame while extending the display duration of frames irrespective of the actual duration of the frames captured in the capture operation so that the user can have time enough to view the frames and select an image from the frames. Note that the playback of images in step S 7  can be done concurrently with the image recording in step S 6 . In other words, one frame can be read and played back each time one frame is recorded.  
         [0073]     Upon image playback, it is determined whether the bookmark button  321  is pressed (step S 8 ). As a result of determination in step S 8 , if the bookmark button  321  has been pressed, the procedure proceeds from step S 8  to step S 9 , in which the image being displayed on the external LCD monitor  220  when the bookmark button  321  is pressed is copied from the internal recording medium  221  and recorded on the removable recording medium  222  (step S 9 ). Then, the procedure proceeds to step S 10 . On the other hand, it is determined in step S 8  that the bookmark button  321  is not pressed, the procedure proceeds from step S 8  to step S 10 .  
         [0074]     Following the above-mentioned processing, it is determined whether the frame-by-frame playback of the captured images is completed, for example, it is determined whether all captured images have been played back (step S 10 ). As a result of determination in step S 10 , if it is determined that the frame-by-frame playback of the captured images is not completed, the procedure returns to step S 8  to continue the frame-by-frame playback. On the other hand, it is determined in step S 10  that the frame-by-frame playback of the captured images is completed, the flowchart of  FIG. 3  is ended to return to a camera main flowchart, not shown. Note that, after the completion of the frame-by-frame playback of the captured images, the user can be confirmed if the user wants to repeat the frame-by-frame playback.  
         [0075]     As described above, according to the first embodiment, since the playback of captured images is performed immediately after completion of imaging in real time, the user can easily select an image to be recorded. This allows the user to select and record the best shot on the removable recording medium easily without fail. Further, since the captured images are recorded on the internal recording medium  221  incorporated in the camera, any one of the captured images can be fetched as necessary later from the internal recording medium  221 . In addition, since only the necessary images can be selected and recorded on the removable recording medium, the best shot images can be recorded efficiently without use of a large-capacity recording medium as the removable recording medium.  
         [0076]     The flowchart of  FIG. 3  shows the operation of the camera  1  in the single-shot mode. When the camera  1  is in a continuous-shot mode, it is determined whether the user has pressed the shutter release button  322  to the second position before shifting from step S 6  to step S 7 . In other words, in the continuous-shot mode, there can be provided a step for repeating the imaging operation and the writing to the recording medium while the user remains pressing the shutter release button at the second position. Then, the procedure can be configured to proceed to step S 7  in  FIG. 3  when the shutter button is released from the second position. This allows the first embodiment to be applied to the continuous-shot mode of the camera  1 .  
       Second Embodiment  
       [0077]     The following describes a second embodiment of the present invention. The second embodiment of the present invention shows an example in which the user can select an image to be recorded on a removable recording medium according to biometric information from a biometric information input device instead of the bookmark button  321 .  
         [0078]      FIG. 4  is a block diagram showing the details of an internal electric circuit configuration of a digital camera as an example of an imaging apparatus according to the second embodiment of the present invention. The structure of the camera  1  itself is the same as that shown in  FIG. 1 . The camera  1  is connected to a biometric information input device  401  as an external device, so that the biometric information input device  401  works instead of the bookmark button  321  in the first embodiment.  
         [0079]      FIG. 5  is an illustration showing such a state that the camera  1  is connected to an electroencephalographic device  501  as an example of the biometric information input device  401 . When the user (examinee) attaches the electroencephalographic device  501  to his or her forehead as shown in  FIG. 6 , the brain wave patterns (including α wave and β wave patterns) of the user are detected through an electrode  501   a  provided in the electroencephalographic device  501 . This signal is input into the Bucom  201  so that the Bucom  201  recognizes the instruction from the user. Note that various devices other than the electroencephalographic device can be considered as the biometric information input device, such as a device for inputting an audio signal and a device for detecting eye blinks or opening/closing of an eyelid of the user.  
         [0080]      FIG. 7  is a flowchart showing a procedure of an image recording method according to the second embodiment of the present invention. Only a different point is that it is determined whether biometric information is input (step S 18 ) instead of determining in step S 8  of  FIG. 3  whether the bookmark button  321  is pressed.  
         [0081]     As described above, according to the second embodiment, the user can select an image in response to input of the biometric information. This can reduce a delay in response time of a human being from viewing an image until pressing the bookmark button  321 .  
         [0082]     While there has been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention not be limited to the exact forms described and illustrated, but constructed to cover all modifications that may fall within the scope of the appended claims.