Abstract:
An image taking device and an image taking method are provided. The image taking device and image taking method allow a shutter to be released without having to apply much force while preventing camera shake that can occur during image taking of a subject and while preventing unintended release of the shutter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Japanese Patent Application No. 2010-036240, filed Feb. 22, 2010, which is hereby incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    Embodiments of the disclosure relate to an image taking device that has a shutter and takes an image by opening and closing the shutter, and an image taking method. 
       BACKGROUND 
       [0003]    Cameras are used as an image capturing device for taking still images of a subject. With a general conventional camera, a user presses a shutter button in order to take a still image of a subject. Completely pressing the shutter button requires the user to exert a certain amount of force. However, fully pressing the shutter button without moving the camera is difficult and often causes camera shake, which results in blurring of the still image. 
         [0004]    One way to take a clear still image without blurring the still image is to fix a camera on a tripod and take a picture without directly pressing the shutter button. The picture can be taken, for example, by connecting a release to the shutter button and manipulating the release to operate the shutter. 
         [0005]    More recently, digital cameras have been introduced that have a touch-sensitive panel or touch pad on the camera. These digital cameras provide shutter button functions at a desired position on the panel or pad so that the user can release the shutter to take an image by touching the position on the panel without using much force. 
         [0006]    For these digital cameras with a touch-sensitive-panel shutter button, methods have been disclosed for taking an image that is unaffected by camera shake. The image is taken by touching the touch-sensitive-panel shutter button. The shutter can also be released when the user&#39;s finger has moved away from the touch-sensitive-panel shutter button. 
         [0007]    However, since a camera shutter button that functions at a certain position on a touch-sensitive panel or touch pad allows the shutter to be released just by touching the position without applying much force, the camera can accidentally release the shutter when something makes contact with the position. For example, the shutter may be accidentally released when the user carries the camera in a pocket or a bag. 
         [0008]    A camera that releases the shutter when the user&#39;s finger has moved away from the shutter button can also accidentally release the shutter when something comes into and out of contact with the shutter-button position. 
         [0009]    Therefore, it is desirable to have an image taking device and an image taking method for allowing a shutter to be released without having to apply much force while preventing camera shake that can occur during shooting of a subject and while preventing unintended release of the shutter. 
       SUMMARY 
       [0010]    An image taking device according to the present disclosure includes: a housing; a shutter contained in the housing; an imaging unit that is contained in the housing and that receives incident light upon opening of the shutter to form an image of a subject; an operation unit that is provided on the housing for performing opening and closing operations of the shutter; and a touch-sensitive panel provided on a first surface of the housing. The operation unit includes a first touch sensor and a second touch sensor that can be touched by a user when the user holds the housing. The operation unit can open and close the shutter after both the first touch sensor has detected a contact and the second touch sensor has detected a contact within a predetermined time period after the contact detected by the first touch sensor. A predetermined portion or area of the touch-sensitive panel functions as the first touch sensor and the second touch sensor may be provided on a second surface of the housing that is different from the first surface. 
         [0011]    Also, an image taking device according to the present disclosure includes a housing; a shutter contained in the housing; an imaging unit that is contained in the housing and that receives incident light upon opening of the shutter to form an image of a subject; and an operation unit that is provided on the housing for performing opening and closing operations of the shutter. The operation unit has a first touch sensor and a second touch sensor that can be touched by a user when the user holds the housing. The operation unit opens and closes the shutter after the first touch sensor has detected a contact and the second touch sensor has detected a contact within a predetermined time period after the contact detected by the first touch sensor. 
         [0012]    The operation unit of the image taking device may open and close the shutter after the first touch sensor has detected a release of the contact and the second touch sensor has detected a contact within a predetermined time period after the release of the contact of the first touch sensor. 
         [0013]    The operation unit of the image taking device may open and close the shutter after the second touch sensor has detected a contact while a contact is being detected by the first touch sensor. 
         [0014]    The operation unit of the image taking device may open and close the shutter after the second touch sensor has detected the release of the contact of the first touch sensor and the second touch sensor has detected a contact within a predetermined time period after the release of the contact. 
         [0015]    The operation unit of the image taking device may, when detecting that the second touch sensor has been touched for at least a predetermined time period, open and close the shutter at predetermined time intervals until the contact is released. 
         [0016]    The operation unit of the image taking device may open and close the shutter when the second touch sensor has detected a contact. 
         [0017]    The operation unit of the image taking device may open and close the shutter when the second touch sensor has detected a release of the contact. 
         [0018]    The image taking device may have a configuration in which the first touch sensor is positioned on a first surface of the housing, and the second touch sensor is positioned on a second surface of the housing that is different from the first surface. 
         [0019]    The image taking device may further include a touch-sensitive panel provided on the housing, and a portion of the touch-sensitive panel may function as at least one of the first and second touch sensors. In this configuration, the portion or area of the touch-sensitive panel that functions as at least one of the first and second touch sensors may be arbitrarily configurable by the user. 
         [0020]    The image taking device according to the present disclosure may further include a touch-sensitive panel provided on the housing. Predetermined areas of the touch-sensitive panel separated by space respectively function as the first and second touch sensors. In this configuration, the predetermined areas of the touch-sensitive panel are arbitrarily configurable by the user. 
         [0021]    The imaging unit of the image taking device may have auto-focusing function and determine a focal length when the first touch sensor has detected a contact. 
         [0022]    The operation unit may have a control unit to perform fingerprint authentication. The control unit may be configured to determine that the first touch sensor has detected a contact when the control unit determines that fingerprint authentication is successful based on a signal that is output when the first touch sensor has detected a contact. 
         [0023]    The image taking device may have two of the first touch sensors, and the two first touch sensors may be provided at positions on the touch-sensitive panel separated by space. The operation unit may open and close the shutter after the two first touch sensors have detected a contact and the second touch sensor has detected a contact within a predetermined time period after the contact detected by the two first touch sensors. 
         [0024]    A portable terminal according to the present disclosure may include the aforementioned image taking device according to the present disclosure, and a data communication function to perform data communication by radio. 
         [0025]    An image taking method according to the present disclosure includes an image taking method for taking an image of a subject by opening and closing a shutter, the method including: detecting a contact, by a first touch sensor provided on a housing of an image taking device; and detecting a contact, by a second touch sensor provided on the housing of the image taking device after the first touch sensor detected a contact. A control unit in the image taking device opens and closes the shutter after the second touch sensor has detected a contact. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0026]      FIG. 1  is a front perspective view schematically showing one illustrative example of an image taking device; 
           [0027]      FIG. 2  is a backside perspective view schematically showing the image taking device shown in  FIG. 1 ; 
           [0028]      FIG. 3  is a block diagram showing an illustrative example of a functional configuration for opening and closing a shutter of the image taking device; 
           [0029]      FIG. 4  is a flowchart of an illustrative method for opening and closing the shutter of the image taking device; 
           [0030]      FIG. 5  is a backside perspective view schematically showing an illustrative example of an image taking device; 
           [0031]      FIG. 6  is a front perspective view schematically showing an illustrative example of an image taking device; 
           [0032]      FIG. 7  is a front perspective view schematically showing the image taking device of  FIG. 6  in a telephone mode; and 
           [0033]      FIG. 8  is a front perspective view schematically showing the image taking device of  FIG. 6  in a camera mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    An image taking device and an image taking method according to embodiments of the present disclosure will be described with reference to the drawings. Embodiments set forth below are for describing embodiments of the present disclosure and are not intended to limit the present disclosure only to those embodiments. Therefore, the present disclosure may be practiced in any of various forms within the spirit thereof. 
         [0035]      FIG. 1  is a front perspective view schematically showing an illustrative example of an image taking device;  FIG. 2  is a backside perspective view schematically showing the image taking device shown in  FIG. 1 ;  FIG. 3  is a block diagram showing an illustrative example of a functional configuration for opening and closing a shutter of the image taking device; and  FIG. 4  is a flowchart of an illustrative method for opening and closing the shutter of the image taking device. In the Figures, a thickness, dimension, and the like of components are not drawn to scale for the sake of clarity. 
         [0036]    As shown in  FIGS. 1 to 3 , an image taking device  1  is illustrated as a digital camera. The image taking device  1  includes an image taking lens  12  and an objective-side window  13  of a finder arranged on a front surface of a housing  11  of the image taking device  1 . The housing  11  contains a shutter  18 , an aperture, an imaging unit  19 , a control unit  100  for controlling image taking operations, and so forth. On a back surface of the housing  11 , a liquid crystal display  15  is embedded. The shutter  18 , aperture, imaging unit  19  and the like are similar to those of a conventional digital camera. 
         [0037]    The liquid crystal display  15  includes a touch-sensitive panel over an entire surface thereof and functions as a finder. The liquid crystal display  15  is also used as a user interface to provide access to image data taken via the image taking lens  12  and various functions of the image taking device  1 . An area (e.g., a portion of the display shown by a dotted line in  FIG. 2 ) of the liquid crystal display  15  that can be touched by a user (e.g., a thumb of the user&#39;s right hand) when the user holds the housing  11  is configured to function as a first touch sensor  20  to detect contact when the user touches the area. The first touch sensor  20  is connected with the control unit  100  and a signal detected by the first touch sensor  20  is sent to the control unit  100 . 
         [0038]    A shutter button  16  for opening/closing the shutter is provided at a position on an upper surface of the housing  11  that can be touched by the user when the user holds the housing  11 . The shutter button  16  includes a touch sensor for detecting contact when the user touches the shutter button  16 . The image taking device  1  is configured to release the shutter  18  to cause light incident through the image taking lens  12  to impinge the imaging unit  19  to form an image of a subject (an optical image) by the user touching the first touch sensor  20  and then the shutter button  16  (a second touch sensor). The shutter button  16  is connected to the control unit  100  and a signal detected by the shutter button  16  is sent to the control unit  100 . 
         [0039]    According to an embodiment, the first touch sensor  20 , the shutter button  16  (the second touch sensor), and the control unit  100  constitute an illustrative example of an operation unit  50  for performing opening/closing operations of the shutter  18  as shown in  FIG. 3 . 
         [0040]    Specifically, releasing (or opening/closing) operations of the shutter  18  may take place as follows. For example, at step S 101  of the flowchart shown in  FIG. 4 , the control unit  100  determines whether the first touch sensor  20  has detected a contact or not. If the first touch sensor  20  has detected a contact (YES at step S 101 ), the method proceeds to step S 102 . If the first touch sensor  20  has not detected a contact (NO at step S 101 ), the method returns to step S 101 . 
         [0041]    At step S 102 , the control unit  100  determines whether the shutter button  16  has detected a contact or not. If the shutter button  16  has detected a contact (YES at step S 102 ), the method proceeds to step S 103 . In step S 103 , the shutter  18  is opened and closed to take an image of the subject. On the other hand, if the shutter button  16  has not detected a contact (NO at step S 102 ), the method proceeds to step S 104 . 
         [0042]    At step S 104 , the control unit  100  determines whether a predetermined time period has elapsed since the first touch sensor  20  detected a contact. If the predetermined time period has elapsed (YES at step S 104 ), the method ends. On the other hand, if the predetermined time has not elapsed (NO at step S 104 ), the method returns to step S 102 . 
         [0043]    In one embodiment, the image taking device  1  does not release the shutter  18  when only the shutter button  16  has been touched without the first touch sensor  20  being touched. In other words, both the first touch sensor  20  and the shutter button  16  are touched or at least detect a contact before the image taking device releases the shutter  18 . The image taking device  1  does not release the shutter  18  as long as the shutter button  16  is not touched, even if the first touch sensor  20  is touched. This can keep the shutter  18  from being released in response to an unintended contact while the image taking device  1  is, by way of example only, in a bag or a pocket. 
         [0044]    In an embodiment, the control unit  100  performs control functions such that the shutter  18  is opened and closed when the control unit  100  determines that the first touch sensor  20  has detected a contact and that the shutter button  16  has detected a contact. This is not limiting, however. The control unit  100  may also open and close the shutter  18  when the control unit  100  determines that the first touch sensor  20  has detected a contact and the release of the contact, and thereafter the detected a contact of the shutter button  16 . 
         [0045]    In this case, the control unit  100  may also control the shutter  18  by opening and closing the shutter  18  when the control unit  100  determines that the shutter button  16  has detected a contact within a predetermined time since when the contact detected by the first touch sensor  20  ceased. 
         [0046]    The control unit  100  may also control the shutter  18  by opening and closing the shutter  18  when the first touch sensor  20  has detected a contact and the shutter button  16  has also detected a contact, or when both the first touch sensor  20  and the shutter button  16  have detected a contact and then the shutter button  16  has detected the release of the contact. 
         [0047]    The control unit  100  may also control the shutter  18  by opening and closing the shutter  18  when, after the first touch sensor  20  and the shutter button  16  have detected contact, the shutter button  16  has detected a contact again within a predetermined time period since when the shutter button  16  detected the release of the first contact. In this case, continuous shooting of the subject is possible. 
         [0048]    Furthermore, the control unit  100  may also perform control such that when the first touch sensor  20  has detected a contact and the shutter button  16  has detected a contact that lasts at least a predetermined time, the shutter  18  is opened and closed at certain time intervals until the shutter button  16  detects the release of the contact. In this case, automatic continuous shooting of the subject is possible. 
         [0049]    In an embodiment, an area of the liquid crystal display  15  that can be touched by the user (e.g., a thumb of the user&#39;s right hand) when the user holds the housing  11  functions as the first touch sensor  20  as described above. This is not limiting, however.  FIG. 5  is a backside perspective view schematically showing an illustrative example of the image taking device  1 . For example, an area of the liquid crystal display  15  that can be touched by the thumb of the user&#39;s left hand when the user holds the housing  11  may be configured to function as the first touch sensor  20  as shown in  FIG. 5 . A desired area of the liquid crystal display  15  can also be set to function as the first touch sensor  20  and may be user-configurable. Further, a liquid crystal display may be provided on the upper surface of the housing  11  and an area of the liquid crystal display on the upper surface that can be touched by the user may function as the shutter button  16 . 
         [0050]    Also, the image taking device  1  may have multiple first touch sensors  20 . For example, the image taking device  1  may have both the first touch sensor  20  shown in  FIG. 2  and the first touch sensor  20  shown in  FIG. 5 . The control unit  100  may control the shutter  18  by opening and closing the shutter  18  when both the first touch sensors  20  have detected a contact and also the shutter button  16  has detected a contact. In this case, the user may be required to hold the housing  11  with both hands and thus can take pictures in a stable position. 
         [0051]    Also, the first touch sensor  20  can also be used as a trigger to start focusing. A conventional, or non-touch-sensor, shutter button is designed to focus the camera when the button is halfway pressed and release the shutter when the button is fully pressed. A touch-sensor shutter button, however, makes it difficult to distinguish between halfway pressing and full pressing. The image taking device  1  eliminates the necessity to include a separate element (a component) acting as a trigger for focusing the image taking device  1  by configuring the control unit  100  to perform control such that a focal length is determined by auto-focusing upon detection of contact by the first touch sensor  20 . The shutter  18  is opened and closed following detection of contact by the shutter button  16 . 
         [0052]    Furthermore, the control unit  100  may include a fingerprint authentication unit to perform fingerprint authentication and may determine that the first touch sensor  20  has detected a contact if the control unit  100  determines that fingerprint authentication is successful based on output from the first touch sensor  20 . In this case, only a particular user is allowed to take pictures. Also, by utilizing the fingerprint authentication as a condition for switching to a picture playback mode, it is also possible to prevent playback of pictures against the user&#39;s will to enhance security. The fingerprint authentication capability may also be configured to be arbitrarily enabled and disabled by the user so that a particular user can choose to permit other users to take or play back pictures. 
         [0053]    By way of example only and not limitation, the first touch sensor  20  may be provided on the back surface of the housing  11  (i.e., the liquid crystal display  15 ) and the shutter button  16  may be provided on the upper surface of the housing  11 . The first touch sensor  20  and the shutter button  16  may be located at any position that can be touched by the user when the user holds the housing  11 . For example, any positions separated by space on the liquid crystal display  15  may have the functions of the first touch sensor  20  and the shutter button  16 . Also, the first touch sensor  20  may be positioned somewhere other than the liquid crystal display  15  on the housing  11 . 
         [0054]    In an embodiment, a portable terminal according to the present disclosure will be described with reference to the drawings.  FIG. 6  is a front perspective view schematically showing an illustrative example of an image taking device. The image taking device in  FIG. 6  may be a portable terminal.  FIG. 7  is a front perspective view schematically showing the portable terminal shown in  FIG. 6  in a telephone mode.  FIG. 8  is a front perspective view schematically showing the portable terminal shown in  FIG. 6  in a camera mode. In the figures, thickness, dimension, and the like of components are not drawn to scale for the sake of clarity. Also, similar components to those of the other embodiments are given the same reference numerals and detailed descriptions of such components are omitted. 
         [0055]    As shown in  FIGS. 6 to 8 , a portable terminal  2  according to an embodiment of the present disclosure includes a folding mobile phone that has camera functions and data communication functions to perform data communication by radio. The portable terminal  2  contains an image taking device having the configuration shown in  FIG. 3  like the image taking device  1 , and a first housing  21  and a second housing  22  are connected with each other by a hinge  23 . 
         [0056]    A liquid crystal display  24  is positioned on the first housing  21  and is formed of a touch-sensitive panel to be operated by the user. The liquid crystal display  24  is connected with a processing circuit contained in the housing  21  and displays user interface screens for various modes and functions as a user interface. For example, when the portable terminal  2  is in the telephone mode, a character/numeric key area  26  is displayed on the liquid crystal display  24  as shown in  FIG. 7 , allowing the user to enter a telephone number or mail text by operating the character/numeric key area  26  as with a conventional mobile phone. 
         [0057]    When the portable terminal  2  is in the camera mode, an area of the liquid crystal display  24  that can be touched by the user (e.g., the thumb of the user&#39;s right of left hand) when the user holds the first housing  21  functions as the first touch sensor  20  to detect a contact when the user touches the area as shown in  FIG. 8 . Another area of the liquid crystal display  24  that can be touched by the thumb of the other hand when the user holds the first housing  21  functions as the shutter button  16 . The first touch sensor  20  and the shutter button  16  are connected with the control unit  100 , and signals detected by the first touch sensor  20  and the shutter button  16  are sent to the control unit  100 . In this embodiment, the control unit  100  may be a part of a processing circuit contained in the first housing  21 . 
         [0058]    On the second housing  22 , a liquid crystal display  25  is positioned. An image taking lens is embedded in an opposite side of the surface of the second housing  22  on which the liquid crystal display  25  is positioned and the liquid crystal display  25  serves as a finder. The second housing  22  contains a shutter, an aperture, an imaging unit, and the like. 
         [0059]    The user can take a picture of a subject with the portable terminal  2  by first switching the portable terminal  2  to the camera mode, holding the first housing  21 , touching the first touch sensor  20  with the thumb of one hand (or other finger) and then the shutter button  16  with the thumb or finger of the other hand. 
         [0060]    The image taking device included in the portable terminal  2  does not open and close the shutter when the shutter button  16  has detected a contact without the first touch sensor  20  also detecting a contact, and the image taking device included in the portable terminal  2  does not open and close the shutter either even if the first touch sensor  20  has detected a contact but the shutter button  16  has not detected a contact, similar to the image taking device  1 . This can prevent the shutter from being released in response to an accidental contact when the portable terminal  2  is carried in a bag or a pocket, for example. The portable terminal  2  also has the focusing and fingerprint authentication functions described herein. 
         [0061]    For the image taking device included in the portable terminal  2 , the first touch sensor  20  and the shutter button  16  may be set at any positions that can be touched by the user when the user holds the first housing  21  or the second housing  22 , similar to the image taking device  1  previously described.