Abstract:
A camera-projection device combines internal display and external projection of images in a portable electronic imaging device, such as a digital camera, a digital camcorder, a cell phone or a PDA. The same light source may be shared between an internal display and external projection and may be located internal or external to the camera-projection device. The same lens, such as a liquid lens, may be employed in image capture and image projection. The same display device may also be shared for internal display and external projection of the images.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    In recent years, rapid technology developments have taken place in the field of digital photography and imaging. Portable electric imaging devices have popularized the market, in part, because of their convenience of use, flexibility, and portability. An electric imaging device refers to any device with digital image capturing capability, including but not limited to a digital camera, a digital camcorder, a cell phone and a PDA. In addition to a view finder, many image recording devices now have an on-device internal display which allows more than one person to preview and review pictures. This is an improvement from traditional film cameras, camcorders, and the like. However, limited by its small size, the display on an internal screen can only accommodate the viewing needs of a few people. For presentations of images to a larger group of viewers, a separate projector has conventionally been employed. However, projection devices are both expensive and inconvenient to use with a personal digital image device. Projection devices tend to be large in size and have many bulky assemblies, making them inconvenient to use to satisfy the instant viewing needs of a large group of viewers. What is needed is a convenient way to enable several people to view images from a portable digital recording device. 
     
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         [0002]    The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the invention. 
           [0003]      FIG. 1  shows an embodiment of an integrated camera-projection device, comprising an image capture unit, a first presentation device, and a second presentation device. 
           [0004]      FIG. 2  is a block diagram of an aspect of an embodiment of a camera-projection device as per the present invention. 
           [0005]      FIG. 3  is a block diagram showing another embodiment of the present invention. 
           [0006]      FIG. 4  is a block diagram shows an aspect of an embodiment of a camera-projection device as per the present invention, where the same lens set is used for both image capture and image projection. 
           [0007]      FIG. 5  is a block diagram showing a different aspect of the embodiment of the present invention shown in  FIG. 4 . 
           [0008]      FIG. 6  is a block diagram showing an embodiment of the present invention where the same light source is used for internal display and external projection of images. 
           [0009]      FIG. 7  is a block diagram showing an embodiment of the present invention, where the same set of lens is used for both image capture and projection and the same light source is used for internal display and external projection of images. 
           [0010]      FIG. 8  is a block diagram shows an aspect of an embodiment of the present invention that uses a Digital Light Processor (DLP). 
       
    
    
     SUMMARY OF THE INVENTION 
       [0011]    The present invention is directed to a system for the combined internal display and external projection of images in a portable electronic imaging device, such as a digital camera, a digital camcorder, a cell phone or a PDA. An embodiment of the integrated camera and projection device having features of the present invention comprises an image capture unit  202 , a digital signaling switch  245 , and a first device first presentation device  230  and second presentation device  270 . The image capture unit  202  may be configured to output a digital representation of at least one image. The digital signaling switch  245  can receive the digital representation and selectively output the digital representation to the first presentation device  230 , or the second presentation device  270 . In particular, the first presentation device  230  may be an internal display device and the second display device  230  may be an external projection device. 
         [0012]    In another embodiment of the present invention, the same lens  410 , which is configured to transmit and focus light on both sides of the lens  410 , may be used to both capture an image and externally project an image. An optical switch may be employed to selectively receive light from either lens  410  or the display device  420  and to output the light to the image capture unit  202  or lens  410  respectively. The same display device  420  is also shared for the internal display of the image and the external projection of the image. 
         [0013]    In another embodiment of the present invention, the same light source  260  may be shared for both the internal display of an image and external projection of the image. This light source may be either internal or external. 
         [0014]    In yet another embodiment of the present invention, a DLP  810  may replace the digital signaling switch  245  and display devices  235  and  250  (as shown in  FIGS. 2 ,  3  and  6 ) or replaces the display device  420 , lens  415  and optical switch  405  (as shown in  FIGS. 4 ,  5 , and  7 ). It may carry out the combined functions of a switch (digital signaling or optical) and a display device. 
         [0015]    These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than as limitations on the present invention. 
         [0017]      FIG. 1  is a illustrative drawing of an integrated camera and projection device  200  comprising an image capture unit  202 , a first presentation device  230 , a second presentation device  270  and a switching mechanism (not shown) which may change between the two display devices to display an image on either the internal screen or an external projection screen. 
         [0018]    An embodiment of the present invention is illustrated in  FIG. 2  (with image processing) and  FIG. 3  (without image processing). Shown is an integrated camera-projection device  200  that comprises an image capture unit  202 , a digital signaling switch  245 , a first presentation device  230  and a second presentation device  270 . 
         [0019]    The image capture unit  202  captures images and outputs digital representations of the images. One example of an image capture unit  202  is shown in  FIG. 2 . This image capture unit  202  comprises optical lens  205 , an image capture device  210 , a compression device  215 , storage  220 , and a decompression device  225 . When the term lens (such as  205 ,  410  and  415 ) is mentioned, one will recognize that the lens may be a single lens, a sequence of lenses or an array of lenses, as desired the specific applications. An image capture device  210  may be any image sensing devices, such as a CCD image chip or a CMOS image chip. On source of CMOS Image sensors is Micron Technology, Inc. of Boise, Id. Once an image is captured, the image may be processed and stored in storage  220 . Image processing may include image compression  215  and decompression  225  as illustrated in  FIG. 2 . A compression device  215  takes an image and digitally compresses it into a smaller size, allowing more images to be stored in the same storage  220 . When an image is ready to be displayed, the decompression device  225  may receive the image data from storage  220 , decompress it and output the image data (or a digital representation of the image). An image can also be stored and outputted without any image processing, as illustrated in  FIG. 3 . A digital signaling switch  245  may receive the digital representation of an image and selectively output it to the first presentation device  230 , the second presentation device  270  or a combination of both. In particular, the first presentation device  230  may be an internal display device and the second display device  270  may be an external projection device in the camera and projection device  200 . An example of the first display device  235  is an LCD. An LCD display may be obtained from Kent Displays Incorporated of Kent, Ohio. Alternatively, a MEMs device may be used. MEMs devices may be obtained from Colibrys of Neuchatel, Switzerland, or Texas Instruments of Dallas, Tex. The first presentation device  230  may comprise an internal screen  240  and a first display device  235 . The second presentation device  270  may comprise a light source  260 , an optical lens  255 , and a second display device  250 . Display device  235  and  250  may be the same type of device. Display device ( 235  or  250 ) may receive the digital representation of an image from the digital signaling switch and project the digital representation optically onto an internal screen  240  or an external screen  250  respectively. Light source  260  may provide light to the second presentation device  270 , which may include second display device  250  and optical lens  255 , to be projected onto an external screen. The light source can be internal or external. Examples of light sources include Xeon bulbs, LEDs, fluoresecent light sources, incandescent light sources, electrical luminescence light sources and natural lights. Similar to optical lens  205 , optical lens  255  may be a single lens or an array of lens. 
         [0020]    Another embodiment of an integrated camera and projection device  200  is shown in  FIG. 4  (with image processing) and  FIG. 5  (without image processing). The integrated camera-projection device  200  comprises an image capturing unit  202 , a display device  420 , a light source  260 , an internal screen  240 , a focusing lens  415 , and an optical switch  405 . In this embodiment, light may be transmitted from the outside through lens  410  and focused on an optical switch  405 . The optical switch  405  receives the light and transmits it to the image capture unit  202 , which in turn may output a digital representation of the image to a displaying device  420 . Optical switches may be obtained from Wanshih Electronic Co Ltd. Of Taiwan. As in the previous embodiment of the invention, the image capture unit  202  may store the digital representation of the image with ( FIG. 4 ) or without additional image processing ( FIG. 5 ). The display device  420  may receive the digital representation of the image from the image capture unit  202  and selectively project the image to an internal screen  240 . Optionally, the image may be projected externally. In this case, the display device  420  may receive the digital representation of the image from image capture unit  202 , and output the digital image optically on lens  415 , which in turn focuses it on the optical switch  405 . The optical switch  405  may then project the optical image through lens  410  onto an external screen. Depending upon the particular type of technology used for the display device  420 , light source  260  may be used to provide illumination. 
         [0021]    In this embodiment, lens  410  may replace lens  205  and lens  255 . Lens  410  having a first and second side should be capable of transmitting and focusing light on both its first and second sides. Therefore, the same lens  410  may be used in image capture and projection. Conventional auto-focus and zoom cameras generally perform focus and zooming by shifting lens with an electromotor. The motor, together with the lens-slide mechanism, makes the system bulky and vulnerable to shock, wear, or contamination with dirt, dust, sand, or rain. Moreover, a motor consumes electrical power. In addition, as the dimensions shrink, it becomes more difficult to assemble systems like motorized auto-focus cameras that contain moving parts. However, researchers at two companies, Philips Research of Eindhoven, the Netherland and Varioptic of France, have successfully developed a fluid lens or liquid lens which solves these problems. The fluid lens or liquid lens consists of two fluids with different refractive index, one an electrically conducting aqueous solution and the other an electrically non-conducting liquid, contained in a transparent tube. Because the volume of the liquid is constant, charging different voltages to the liquids will cause the curvature of their interface to change. Since the liquids have different refractive indices, their interface can act as a variable-focus lens. Because a liquid lens changes shape instead of position, it should not require a motor. Since liquids are density matched, they are not susceptible to strong impulse forces. The energy to drive the liquid lens may also be extremely low. Lens (such as  410 ) may employ one or several fluid/liquid lens alone or in combination with conventional lens. 
         [0022]      FIGS. 6 and 7  show embodiments of an integrated camera and projection device where the same light source  600  is used for displaying an image on an internal screen and projecting the same image out on an external screen. As in  FIG. 6 , the light source  600  can be internal or external. Examples of the light source  600  may include a Xeon bulb, an LED, a fluorescent light source, an incandescent light source, an electrical luminescence and natural light.  FIG. 6  illustrates the shared light source  600  in an embodiment similar to that shown in  FIG. 2 . The shared light source  600  can also be used in the embodiment as illustrated in  FIG. 3 .  FIG. 7  illustrates the same light source  600  in an embodiment as shown in  FIG. 4 . The same light source  600  may also be used in an embodiment as shown in  FIG. 5 . 
         [0023]    In  FIG. 6 , light source  600  selectively provides light to the second presentation device  270 , which comprises a display device  250  and optical lens  255 ; or to the first presentation device  230 , which comprises a display device  240  and internal screen  235 . In  FIG. 7 , light source  600  provides light to the display device  420 , which may also receive a digital representation of the image from image capture unit  202 , and then output the digital representation of the image optically to either the internal screen  240  or the optical switch  205 , which in turn may project the image out through lens  410 . 
         [0024]    Another embodiment of an integrated camera and projection device is shown on  FIG. 8 , where a DLP  810  replaces the digital signaling switch  245  and display devices  235  and  250  (as shown in FIGS.  2 , 3  and  6 ). The DLP  810  may also replace the display device  420 , lens  415  and optical switch  405  (as shown in  FIGS. 4 ,  5 , and  7 ). In this embodiment, lens  410  should be capable of transmitting and focusing light on both its first and second sides. The same light source  300  may be used for either internal display or external projection. To capture an image, light may be transmitted through lens  410 , and focused on DLP  810 , which then reflects it to the image capture unit  202 . To display an image, the image capture unit  202  may output a digital representation of the image to DLP  810 . Together with light from light source  600 , the digital representation of the image may be projected optically either through lens  410  onto an external screen or directly to an internal screen  240 . 
         [0025]    The foregoing descriptions of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The illustrated embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.