Abstract:
A digital camera for capturing the image of a document comprising two detachable components. A camera pickup component comprises a lens system, a digitizing photo-receiver, and a transceiver. A camera control component comprises a display, a trigger button, and a transceiver, wherein said camera pickup transceiver and said camera control transceiver exchange control and image information. The camera pickup component may be held over a document in one hand, while the camera control component is held separately in the other hand to increase ease of use and reduce blurred images.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to digital cameras, and more particularly, to a two piece digital camera improving ease of use and image quality.  
         BACKGROUND OF THE INVENTION  
         [0002]    Digital cameras may be used to capture the image of a document much more rapidly than standard image scanners. A digital camera has a two dimensional image sensor array which captures an entire image simultaneously. A standard image scanner has a one dimensional image sensor array which must be moved over a document, producing individually detected lines which must then be pieced together to form a complete image. Digital cameras are described in the following application and patents which are hereby incorporated by reference for all that is disclosed therein. U.S. patent application, Ser. No. ______ , for DIGITAL CAMERA FIELD LENS of Donald Stavely (Attorney docket number HP: 10971803-1), U.S. Pat. No. 4,131,919, U.S. Pat. No. 4,420,773, and U.S. Pat. No. 4,541,010.  
           [0003]    Conventional digital cameras are clumsy and ill suited for document imaging. A user must hover over the document while looking through a viewfinder and adjusting the focus or depth of field. The camera must be moved up or down to crop the image properly. Finally, the user must carefully press a button to take the picture, often resulting in camera motion. This camera motion can cause blurring and misalignment in the final image.  
           [0004]    Digital cameras have been mounted on tripods or other types of fixed support arms to hold the camera steady. This solution has the disadvantage of requiring additional costly and bulky equipment. In addition, tripods and other such camera supports for document imaging reduce the portability of the camera system, which would otherwise be an advantage of digital cameras.  
           [0005]    Tripods and other such camera supports are also difficult to set up and adjust. To adjust the crop area, or target area, on the document, the camera is raised or lowered with respect to the document. To do this, tripod legs must be adjusted or adjustment screws must be turned. Also the photographer must still hover over the tripod mounted camera to look through the viewfinder. Finally, care must be taken when pressing the camera button even with a tripod, as a tripod only limits camera movement, rather than eliminating it.  
           [0006]    A need therefore exists for a digital camera system which can be more easily positioned over a document. A further need exists for a digital camera system with an improved viewfinder display. An additional need exists for a digital camera system in which camera motion caused by pressing a trigger button does not affect image quality.  
         SUMMARY  
         [0007]    To assist in achieving the aforementioned needs, the inventor has devised a two piece digital camera for document image capture. Thus the invention may comprise a digital camera having a camera pickup component and a physically separate, independently positionable camera control component. The camera pickup component may comprise a lens system, a digitizing photo-receiver, and a transceiver. The camera control component may comprise a display, a trigger button, and a transceiver. The camera pickup transceiver and the camera control transceiver exchange control and image information.  
           [0008]    The camera pickup and control components may also comprise interlocking clips for connecting the two components together as one unit. When a release button is pressed on the interlocking clips the pickup and control components separate into two individual units to be held in each hand of the user.  
           [0009]    In the preferred embodiment, the camera pickup and camera control transceivers comprise infra-red transmitters and receivers. Alternatively, the transceivers may comprise radio frequency transceivers or may be connected by one or more conductive wires. Other signal transmission transceivers now known or later developed may also be used.  
           [0010]    The camera pickup component transmits thumbnail images of the document, i.e., low resolution images, which are updated regularly and relatively quickly and are shown in the display of the camera control component. When the camera has been positioned as desired by monitoring the display in the control component, the trigger button in the camera control component is pressed. The camera control component transmits a command to the camera pickup component, causing the digitizing photo-receiver to capture a full resolution image of the document. The image may then be stored either in the camera pickup component or the camera control component. The two components may be held in opposite hands of the photographer or may be otherwise separately positioned, for example by hand positioning the pickup component while the control component is supported on a table top or bracket.  
           [0011]    These and other important features and embodiments of the present invention will be further explained in, or will become apparent from, the accompanying description, drawing and claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    An illustrative and presently preferred embodiment of the invention is illustrated in the drawing, in which:  
         [0013]    [0013]FIG. 1 is a diagram illustrating the elements of a two piece digital camera for document image capture;  
         [0014]    [0014]FIG. 2 is a diagram illustrating the use of a two piece digital camera in which the display comprises an eyepiece; and  
         [0015]    [0015]FIG. 3 is a diagram illustrating the use of a two piece digital camera in which the display comprises a panel. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    A digital camera is used to take pictures which are stored digitally, in the form of electrical signals, rather than storing the pictures visually using chemicals in photographic paper. Digital images produced by a digital camera must be processed by a computer to view or print them. Digital cameras may be used to capture the image of a document in one brief operation, unlike scanners which must scan over the surface of the document.  
         [0017]    [0017]FIG. 1 illustrates a preferred embodiment of a digital camera for capturing the image of a document. The digital camera comprises two individual components, a camera control component  2  and a camera pickup component  4 . Each has a separate housing, allowing the camera control component  2  to be held in one hand while the camera pickup component  4  is held in the other. Each component is preferably of a size and shape that is easily held and manipulated with one hand. Each component  2  and  4  may have an interlocking clip  11 ,  13 , respectively, for connecting the camera control component  2  to the camera pickup component  4 . The digital camera may therefore be clipped together into one integrated unit, or may be separated to facilitate use in document imaging, as will be described hereafter. The interlocking clip may comprise any connection mechanism, e.g., friction fit, latch and catch, screws, detents, sleeves, brackets, etc., depending upon the type of housing used for the camera control component  2  and the camera pickup component  4 . Alternatively the camera may be provided without an interlocking clip.  
         [0018]    The camera pickup component  4  comprises an optical system  40  and a digitizing photo-receiver  36  for producing a digital image of a document (e.g.,  64  FIG. 2) or other subject. Optical systems and digitizing photo-receivers (two dimensional photosensor arrays) for digital cameras are well known in the art. A controller and memory system  34  processes and stores the electrical image information produced by the digitizing photo-receiver  36 . The memory may be for example a non-volatile memory such as an EEPROM, a RAM, or other conventional memory device. A power source  32  preferably includes a battery and a battery circuit for regulating the voltage and current levels from the battery and for maximizing battery life. Such power sources are conventional and well known in the art.  
         [0019]    The camera control component  2  also comprises a controller and memory system  34  and a power source  20 . A display  10  in the camera control component  2  acts as the viewfinder of the digital camera, allowing the user to position and focus the camera pickup component  4  properly. A trigger button  6  causes the digital camera to take and store an image.  
         [0020]    The camera control component  2  and the camera pickup component  4  each have a transceiver  12  and  24  which allow the components to exchange control and image information. The camera control component  2  transceiver  12  comprises a transmitter  14  for transmitting information to a receiver  26  in the camera pickup component  4  transceiver  24 . The camera pickup component  4  transceiver  24  also contains a transmitter  30  for transmitting information to a receiver  16  in the camera control component  2 . The transceivers may be of a wireless type such as infra-red, radio frequency, etc., or alternatively may be physically linked as by electrical signal transmission leads, optical fiber or other signal transmission media.  
         [0021]    In one preferred embodiment, illustrated in FIG. 2, the display (e.g.,  10 ) in the camera control component  50  comprises an eyepiece display  52 . To capture the image of a document in this embodiment, the user first separates the camera control component  50  from the camera pickup component  58  by releasing the interlocking clips. The camera control component  50  is held in one hand  54  while the camera pickup component  58  is held in the other hand  60 . The eyepiece display  52  is brought to the user&#39;s eye, and the camera pickup component  58  is held over a document  64  or other such subject. The camera pickup component  58  is oriented to direct the optical system  40  at the document  64 .  
         [0022]    As light reflects from the document  64 , the reflected image light  62  enters the optical system  40  of the camera pickup component  58  and is converted to a digital representation of the image, either as a low resolution thumbnail image or as a final full resolution image.  
         [0023]    In this preferred embodiment, the camera pickup component  58  continuously processes low resolution thumbnail images and transmits them to the camera control component  50  via the transceivers  12  and  24 . The thumbnail images are displayed in the eyepiece display  52 , allowing the user to orient and position the camera pickup component  58 . Low resolution images may be processed and transmitted more quickly than full resolution images and are thus usefully employed where processing power and/or signal transmission speed are use limiting considerations. For example, an exemplary full resolution image may be 640 pixels wide and 480 pixels high, while an exemplary low resolution image may be only 32 pixels wide and 24 pixels high. In this case, a full resolution image would require the transmission of at least 307,200 pixels, but a low resolution image would require the transmission of around 768 pixels. However, full resolution image capture and transmission could also be used for orienting the camera if desired.  
         [0024]    When the camera pickup component  58  is positioned as desired, the user presses the trigger button  56  of the camera control component  50 . The camera control component  50  then transmits a command to the camera pickup component  58 , causing it to take a full resolution image of the document  64 . The image may then be stored in the memory  34  of the camera pickup component  58 . Alternatively, the full resolution image may be transmitted to the camera control component  50  and stored in its memory  22 .  
         [0025]    In another embodiment, the display (e.g.,  10 ) comprises a panel display  72  as illustrated in FIG. 3. The camera control component  70  may be held in one hand  74 , while the camera pickup component  78  is held in the other hand  80 . The panel display  72  in the camera control component  70  may be held at arms length or at any comfortable viewing distance from the user, while the camera pickup component  78  is positioned over a document  82  as described above. Alternatively panel display  72  may be positioned on a table (not shown) or other support where it may be easily viewed by the user.  
         [0026]    The user positions the camera pickup component  78  as desired by monitoring the panel display  72  while moving the camera pickup component  78  over the document  82 . When the desired image is seen in the panel display  72 , the user presses the trigger button  76  on the camera control component  70  to process and store a full resolution image of the document  82 .  
         [0027]    The trigger button  6 ,  56 , and  76  is located on the camera control component  2 ,  50 , and  70 , isolating camera movement caused by pressing the button. As a result, the camera pickup component  4 ,  58 , and  78  can be held steady in the non-moving hand  60  and  80  to avoid blurring the image. The display  10 ,  52 , and  72  is also located on the camera control component  2 ,  50 , and  70 , allowing the user to easily see the image and position the camera pickup component  4 ,  58 , and  78  without hovering over the document  64  and  82 .  
         [0028]    It will also be appreciated that although the separate control and pickup components may be held in opposite hands during use, that either or both components may also be positioned on a support surface or mount during use. For example the pickup component could be supported above a document on a tripod or the like with the control component positioned on a flat surface next to the document.  
         [0029]    Having described the two piece digital camera for capturing a document image in general, as well as some of its more significant features and advantages, some of the various embodiments of such a digital camera will now be described in more detail.  
         [0030]    As shown in FIG. 1, the optical system  40  may comprise any system or apparatus for directing image light (e.g.,  62  FIG. 2) onto the digitizing photo-receiver. One such optical system  40  is the lens system described in U.S. patent application, Ser. No. _____,_ for DIGITAL CAMERA FIELD LENS of Donald Stavely (Attorney docket number HP: 10971803-1). The optical system  40  may also comprise infinite focus lenses, auto-focus lenses, manual focus lenses, or zoomable lenses.  
         [0031]    The digitizing photo-receiver  36  may comprise any type of optical sensor for converting image light into an electrical representation of the image, such as a two dimensional array of optical sensors. Optical sensor devices which could be used include contact image sensors (CIS) and charge coupled device (CCD) image sensors, or other known or later developed sensors.  
         [0032]    The display  10  may comprise any type of display for displaying either low resolution thumbnail images or full resolution images. In a preferred embodiment a display (e.g.,  52  and  72 ) comprises a liquid-crystal display (LCD) panel. Alternatively, the display may comprise a thin-film transistor (TFT) display, a plasma display panel (PDP), a light-emitting diode (LED) array or any other type of display panel now known or which may be developed in the future.  
         [0033]    The transceiver  12  and  24  of the preferred embodiment comprises an infra-red transmitter and receiver. Alternatively, the transceiver  12  and  24  may comprise any transmitter and receiver suitable for transmission and reception across a distance of up to about four feet, such as a radio frequency (RF) transceiver, or may comprise a cable connection across one or more conductive wires, optical cables, etc.  
         [0034]    While illustrative and presently preferred embodiments of the invention have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.