Abstract:
An image capturing device comprises an audio transducer, a processor, and a memory. The memory receives an audio signal produced by the audio transducer and gated by the processor. The memory includes an audio buffer capable of continuously accumulating the audio signal until the buffer becomes full, and thereafter storing a predetermined time amount of the most recent audio signal. The memory further includes one or more audio storage cells capable of storing at least a portion of the audio signal held in the audio buffer. The processor is capable of storing at least a portion of the audio signal from the audio buffer into an audio storage cell of the one or more audio storage cells.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to an audio capture function in an image capturing device, and more particularly to a continuous audio capture in an image capturing device.  
         BACKGROUND OF THE INVENTION  
         [0002]    Still image capturing devices are used to visually memorialize scenes, events, or items. Still image capturing devices, such as cameras, include a lens, a shutter, and either a photosensitive film or an electronic image sensor. In addition, most modern cameras include a processor and/or other control electronics that function to control shutter speed, aperture, flash, focus, etc.  
           [0003]    It has become increasingly common in image capturing devices to also capture a small audio sequence associated with an image. By capturing audio along with an image, an image capturing device may preserve voices, music, laughter, etc. to enhance the enjoyment of a captured image. This may be very desirable to the user of the image capturing device. In addition, an audio recording may be easily and efficiently used to record data about the captured image, such as date, occasion, people in the image, etc.  
           [0004]    In the prior art, an image capturing device typically included audio apparatus that is triggered upon an image capture, i.e., upon a press of a shutter button or upon some other manual input by the user. Therefore, in order to capture audio according to the prior art, the user must press a button and generally gets a fixed audio recording captured over a fixed time period. Often, a separate button is provided to perform audio recording. Recording continues as long as the button is pressed (subject to a time limit), but this can only be done after the image is captured.  
           [0005]    The audio capture according to the prior art has several drawbacks. It is either linked to an image capture or is dependent on foresight and preparation by the user. In the prior art approach the user must enable the audio capture at a desired time. This is unfortunate, as a sound may trigger a desire to capture an image (and the associated audio). For example, a child&#39;s laugh may trigger a desire to capture both an image and the laugh. This is not possible in the prior art.  
           [0006]    Therefore, there remains a need in the art for improvements in image capturing devices with audio capture capability.  
         SUMMARY OF THE INVENTION  
         [0007]    An image capturing device comprises an audio transducer, a processor, and a memory. The memory receives an audio signal produced by the audio transducer and gated by the processor. The memory includes an audio buffer capable of continuously accumulating the audio signal. The memory further includes one or more audio storage cells capable of storing at least a portion of the audio signal held in the audio buffer. The processor is capable of storing at least a portion of the audio signal from the audio buffer into an audio storage cell of the one or more audio storage cells. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a schematic diagram of an image capturing device according to one embodiment of the invention;  
         [0009]    [0009]FIG. 2 is a flowchart of an audio capture method according to another embodiment of the invention; and  
         [0010]    [0010]FIG. 3 is a flowchart of an audio capturing method according to yet another embodiment of the invention.  
     
    
     DETAILED DESCRIPTION  
       [0011]    [0011]FIG. 1 is a schematic diagram of an image capturing device  100  according to one embodiment of the invention. The image capturing device  100  includes a lens apparatus  101 , an optional lens cover  102 , a processor  105 , an audio transducer  110 , an optional audio conditioning circuit  116 , a shutter button  123 , and a memory  130 .  
         [0012]    The processor  105  may be any type of general purpose processor. The processor  105  executes a control software program contained in the memory  130 . In addition, the processor  105  receives inputs and controls the overall operation of the image capturing device  100 . The processor  105  may optionally include an analog-to-digital converter (A/D) that converts a received audio signal into a digital audio signal.  
         [0013]    The shutter button  123  may be employed by a user to perform an image capture operation. In addition, the shutter button  123  may be used in combination with other input devices in order to select modes and control operation of the image capturing device  100 .  
         [0014]    The audio transducer  110  may be any type of audio transducer capable of converting sound into a representative electrical audio signal. The audio transducer  110  may be a microphone, for example.  
         [0015]    The optional audio conditioning circuit  116  may be included if audio signal processing between the audio transducer  110  and the processor  105  is required. Therefore, the optional audio conditioning circuit  116  may include any type of audio processing circuitry as is known in the art, such as amplification, filtering, etc. In addition, the audio conditioning circuit  116  may include an A/D converter that converts an analog electrical signal from the audio transducer  110  into a representative digital audio signal. The resultant digital audio signal may be received by the processor  105  and relayed to the memory  130 , or may be directly gated into the memory by the processor  105 .  
         [0016]    The memory  130  may be any type of memory, including all types of random access memory (RAM), flash memory, magnetic storage media such as magnetic disc, tape, etc., or optical or bubble memory. The memory  130  may include, among other things, an audio buffer  136  and one or more audio storage cells  133 . In addition, if the image capturing device  100  is a digital image capturing device, the memory  130  may store digital images (not shown). Furthermore, the memory  130  may store a software program to be executed by the processor  105 .  
         [0017]    The audio buffer  136  may continuously store a predefined length of a received digital audio signal gated by the processor  105  when the image capturing device  100  is in an audio capture mode. The audio buffer  136  therefore may contain a predetermined time segment of the (captured) audio signal. The predetermined time segment may be 30 seconds of captured audio, for example. However, it should be understood that the predetermined time segment may be of any time length, and is limited only by the amount of memory the designer wishes to dedicate to this purpose.  
         [0018]    The processor  105  gates the audio signal and therefore allows the audio signal into the audio buffer  136  when the image capturing device  100  is in the audio capture mode. The processor  105  may gate the audio signal by controlling the making or breaking of an audio path (i.e., switching). Alternatively, the processor  105  may gate the audio signal by receiving and selectively relaying it to the memory  130 . In another alternative, the processor  105  may control the supply of electrical power to the audio transducer  110 , if the audio transducer  110  is an active device.  
         [0019]    The audio buffer  136  may continuously accumulate a predefined time amount of the audio signal during the audio capture mode. The audio capture mode may be enabled whenever the lens cover  102  has been opened and the lens apparatus  101  is exposed, for example. Alternatively, the audio capture mode may enable whenever the image capturing device  100  is powered on, such as through a camera power switch. In yet another alternative, the audio capture mode may be enabled whenever the shutter button  123  is partially depressed; such as in image capturing devices that have a two-stage shutter button  123  that may be partially depressed in order to perform a focus and/or flash measurements.  
         [0020]    The one or more audio storage cells  133  may store all or part of the digital audio signal contained in the audio buffer  136 . Therefore, when the user of the image capturing device  100  desires to capture audio at some point in time at or near an image capture, the user may specify that the contents of the audio buffer  136  be copied to one of the audio storage cells  133 . In this manner, the user does not have to worry about setting up or causing an audio capture. This enables a user to capture audio (along with an image) without having to plan to do so beforehand, and may allow the user to do so even after the image capture has occurred. Due to circumstances surrounding an image capture, the user may not have had the forethought to enable an audio capturing mode, as is necessary in the prior art. Moreover, the user may select a portion of an audio signal to be stored. Therefore, if the image capturing device  100  captures 30 seconds of audio, for example, the user may select and store only a portion. This may be a portion captured before, during, or after the associated image capture.  
         [0021]    [0021]FIG. 2 is a flowchart  200  of an audio capture method according to another aspect of the invention. In step  201 , the image capturing device  100  determines whether it is in an audio capture mode. This may include monitoring a lens cover position, monitoring a power switch or power state, etc. If it is not, the method does not proceed. Otherwise, it proceeds to step  206 .  
         [0022]    In step  206 , an audio signal is continuously recorded into the audio buffer  136 . This is continuously done during an audio capture mode. The audio signal is continuously stored in the buffer until the buffer is full. Thereafter, the signal is overwritten from the beginning of the buffer, such as in a first-in, first-out shift operation.  
         [0023]    In step  240 , the image capturing device  100  determines whether an image has been captured (i.e., a press of the shutter button  123 , for example).  
         [0024]    In step  244 , after a picture has been taken, the image capturing device  100  stores at least a portion of the recorded audio into an audio storage cell  133 . This may include transferring all or part of the audio buffer  136  to an audio storage cell  133 . In this manner, the user of the image capturing device may automatically capture and record audio around an image capture time. In a digital image device, the audio signal is stored with an address of the corresponding stored image, or the image may be stored with the address of the corresponding audio signal.  
         [0025]    [0025]FIG. 3 is a flowchart  300  of an audio capturing method according to yet another embodiment of the invention. In step  302 , the image capturing device  100  determines whether it is in an audio capture mode, as previously discussed.  
         [0026]    In step  307 , an audio signal is continuously recorded, as previously discussed.  
         [0027]    In step  313 , a store command input is detected. This may be some manner of input by the user. For example, an image capturing device may include an audio store button or may include a user interface that displays menus or list of commands among which the user may choose, including an audio store command. In addition, the user may optionally enter a command that specifies only a portion of the audio buffer  136  be transferred and recorded. Alternatively, the store input command may be configured so that it is automatically issued in conjunction with an image capture. In another alternative embodiment, the store input command may be issued a predetermined delay time period after the image capture. If the store command input is detected, the method proceeds to step  319 . Otherwise, it exits.  
         [0028]    In step  319 , the recorded audio is stored. As previously discussed, this comprises copying all or part of the digital audio signal from the audio buffer  136  to an audio storage cell  133 . In this manner, the user may store audio before, during, or after an image capture.