Patent Document

CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is related to application Ser. No. xx/xxx,xxx entitled, “Automatic Selection of Illumination Source for Hybrid Digital Cameras,” filed on or about the same date as the present application, and hereby incorporated herein by reference. application Ser. No. xx/xxx,xxx discloses and claims a method for the automatic selection of illumination sources by digital cameras. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to the field of photography and more specifically to the field of lighting of photographic subjects for still and video imaging.  
       BACKGROUND OF THE INVENTION  
       [0003]     Many modem digital cameras include both a still photography mode and a video mode. In the video mode, short moving video clips are captured by the digital camera. These video clips may range in length from a few seconds to several minutes. The lighting requirements for these two modes of operation are significantly different. In digital still cameras a very bright flash for scene illumination is often desired so that high shutter speeds can be used to stop and freeze any motion in the scene being captured. In video mode, a more uniform constant light source is desired.  
       SUMMARY OF THE INVENTION  
       [0004]     A lighting device for a digital camera is built including one or more light emitting diodes (LEDs) along with a strobe. The LEDs are configured to provide lighting of the subject during a video mode of the camera and the strobe is configured to provide lighting of the subject during a still mode of the camera. These independent light sources may share a common reflector in some embodiments, while in other embodiments they may use separate reflectors. This lighting device may be built-in to a digital camera or in some embodiments may be configured as a separate device controlled by the digital camera.  
         [0005]     Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is front view of an example embodiment of a digital camera including a LED and strobe lighting device according to the present invention.  
         [0007]      FIG. 2  is front view of an example embodiment of a digital camera attached to a lighting device including a LED and a strobe according to the present invention.  
         [0008]      FIG. 3  is a cross-sectional view of a lighting device including two LEDs, a strobe, and a single reflector according to the present invention.  
         [0009]      FIG. 4  is a cross-sectional view of a lighting device including one LED, a strobe, and two reflectors according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0010]      FIG. 1  is front view of an example embodiment of a digital camera including a LED and strobe lighting device according to the present invention. An example embodiment of a camera  100  constructed according to the present invention may include a camera body  102 , a lens  106 , a LED and strobe lighting device  104 , an external viewfinder window  108 , a shutter release  110 , and a control  112 . As with all digital cameras, this example embodiment of the present invention includes a circuit  114  electrically connected to the shutter release  110 , electrically connected to the LED and strobe lighting device  104 , and configured to control the lighting device  104  by activating either the LED or the strobe within the lighting device. This circuit  114  includes a means for detecting when the shutter release  110  is depressed. In some example embodiments of the present invention, the circuit  114  may also be configured to detect when the shutter release  110  is partially depressed. In an example embodiment of the present invention, the control  112  may be used to select a mode of the digital camera. These modes may include a still photo mode and a video mode.  
         [0011]      FIG. 2  is front view of an example embodiment of a digital camera attached to a lighting device including a LED and a strobe according to the present invention. In this embodiment of the present invention the lighting device including a LED and a strobe is configured as a separate device from the digital camera. Similar to the digital camera of  FIG. 1 , this example embodiment of a camera includes a camera body  202 , a lens  206 , an external viewfinder window  208 , a shutter release  210 , a control  212 , a hot shoe  220  including hot shoe electrical contacts  222 . As with all digital cameras, this example embodiment of the present invention includes a circuit  224  electrically connected to the shutter release  210 , electrically connected to the hot shoe electrical contacts  222  and the flash control outputs  218 . The circuit  224  is configured to control one or more external lighting devices through the hot shoe electrical contacts  222  or the flash control outputs  218 . This circuit  224  includes a means for detecting when the shutter release  210  is depressed. In some example embodiments of the present invention, the circuit  224  may also be configured to detect when the shutter release  210  is partially depressed. In an example embodiment of the present invention, the control  212  may be used to select a mode of the digital camera. These modes may include a still photo mode and a video mode. This example embodiment also includes dedicated flash control outputs  218  separate from the hot shoe electrical contacts  222 . Both the flash control outputs  218  and the hot shoe electrical contacts  222  may be used to control a mode of the lighting device  200 . This example embodiment of a lighting device  200  includes a combined LED and strobe  204 , flash control inputs  216 , and a switch  214 . The flash control inputs  216  and the switch  214  may be used to select a mode of the flash. In a still mode, the strobe of the flash is activated when triggered by the camera. In a video mode, the LED is activated when triggered by the camera. In an example embodiment of the present invention, the switch  214  may allow a user to override the mode signal communicated from the camera through the flash control outputs  218  into the flash control inputs  216  of the lighting device  200 .  
         [0012]      FIG. 3  is a cross-sectional view of a lighting device including two LEDs, a strobe, and a single reflector according to the present invention. In this example embodiment of the present invention a lighting device  300  is built including a body  302  with supports  312  for a reflector  308  and a lens  310 . In this example embodiment two LEDs  306  share the common reflector  308  with a strobe tube  304 . Those of skill in the art will recognize that many different configurations of LEDs and strobe tubes may be used within the scope of the present invention. While this example embodiment includes two LEDs  306  positioned on either side of a strobe tube  304  other embodiments may use any number of LEDs  306  positioned in widely varying locations with respect to the strobe tube  304 . Also, other embodiments of the present invention may use more than one strobe tube  304 .  
         [0013]      FIG. 4  is a cross-sectional view of a lighting device including one LED, a strobe, and two reflectors according to the present invention. In this example embodiment of the present invention a lighting device  400  is built including a body with supports  414  configured to mechanically affix a first reflector  406 , a first lens  410 , a second reflector  408 , and a second lens  412 . A strobe tube  402  is configured to use the first reflector  406  and the first lens  410 , while a LED  404  is configured to use the second reflector  408  and the second lens  412 . This embodiment of the present invention includes a hot shoe foot  416  including flash input connections  418  configured to electrically couple to the hot shoe of the camera shown in  FIG. 2 . Those of skill in the art will recognize that many different quantities and configurations of strobe tubes and LEDs may be used within the scope of the present invention. While many implementations of the present invention will use white LEDs for video illumination, other colors of LEDs may be used either in place of, or in addition to white LEDs to change the color of the light generated by the lighting device.  
         [0014]     In other embodiments of the present invention, the LED and strobe illumination device may be configured as a device separate from the camera. It may attach to the camera via a hot shoe, and additional signals within the hot shoe may control the mode of the illumination device. In some simple embodiments of the present invention the mode of the illumination device may be controlled by the user of the camera with a switch.  
         [0015]     The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The 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 various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.

Technology Category: h