Camera with acceleration sensor

Abstract

A method and system for determining camera positioning information from an accelerometer mounted on a camera. The accelerometer measures the orientation of the camera with respect to gravity. Orientation measurement allows user interface information to be displayed in a “right side up” orientation on a viewfinder for any camera orientation. Alternatively, an artificial horizon indicator may be displayed in the viewfinder. The accelerometer may also measure camera movement. Camera movement information together with camera orientation can be used to determine camera usage. Additionally, camera movement information can be used to determine a minimum shutter speed for a sharp picture.

1 . A method for aligning a camera to the Earth's horizon, the method comprising: 
 a. providing the camera having a viewfinder display and an accelerometer for determining camera orientation with respect to gravity;    b. determining an orientation of the camera with respect to gravity using the accelerometer; and    c. displaying an artificial horizon indicator on the viewfinder display based on the determined orientation of the camera.    
   
   
       2 . A method according to  claim 1  further comprising: 
 d. aligning the camera with respect to the earth's surface using the artificial horizon indicator on the viewfinder display.    
   
   
       3 . A method according to  claim 1  further comprising: 
 d. displaying an reference indicator for the camera on the viewfinder display to aid in aligning the camera with respect to the earth's surface.    
   
   
       4 . A method for orienting icons displayed in a camera image comprising: 
 a. providing a camera, the camera including an accelerometer for determining an orientation of the camera with respect to gravity and a viewfinder display;    b. determining an orientation of the camera with respect to gravity using the accelerometer; and    c. displaying a given icon on an image produced by the camera, wherein the given icon's orientation is based at least in part on the determination of the orientation of the camera using the accelerometer.    
   
   
       5 . A method according to  claim 4 , where the image produced by the camera is displayed on the viewfinder display.  
   
   
       6 . A method according to  claim 4 , wherein displaying the given icon on an image produced by the camera includes printing the icon on a printed image.  
   
   
       7 . A method for adjusting image exposure time for a camera to reduce movement-induced image blurring, 
 a. providing the camera, the camera including an accelerometer;    b. measuring a peak-to-peak acceleration magnitude using the accelerometer for a given time duration; and    c. adjusting the image exposure time based at least in part on the peak-to-peak acceleration magnitude over the given time duration.    
   
   
       8 . A method according to  claim 8 , wherein adjusting the image exposure time includes calculating a minimum shutter speed.  
   
   
       9 . A method according to  claim 9 , wherein the minimum shutter speed is calculated as a function of the square of the inverse of the peak-to-peak acceleration magnitude divided by the camera focal length.  
   
   
       10 . A method according to  claim 4  wherein adjusting the image exposure time includes looking up a minimum shutter speed versus the peak-to-peak acceleration magnitude over the given time duration in a look-up table.  
   
   
       11 . A method for determining a state of utilization for a camera comprising: 
 a. providing the camera, the camera including an accelerometer for determining an orientation of the camera with respect to gravity and a peak-to-peak acceleration magnitude over a given duration;    b. determining an orientation of the camera using the accelerometer;    c. determining a peak-to-peak acceleration magnitude over a given duration using the accelerometer;    d. identifying the state of utilization for the camera based at least in part on the camera orientation determination and the peak-to-peak acceleration magnitude over a given duration.    
   
   
       12 . A method according to  claim 6  further including: 
 e. placing the camera in a lower power state based on the state of utilization.