Automatic speed optimization

Abstract

Embodiments of the present invention are directed to an apparatus and a method for synchronizing the velocity of an image of a moving object or target and the clocking of image sensor elements used to track the moving target. In one embodiment, an imaging apparatus comprises a plurality of rows of image sensor elements spaced from each other, extending in a first direction, and being configured to sense a set of image elements of a target moving in the first direction, to integrate light from the rows of image sensor elements into corresponding pixel values, and to shift the pixel values along the rows of image sensor elements in the first direction according to a clock rate, the plurality of rows having the same number of image sensor elements, each row having image sensor elements that are different in length from the image sensor elements of the other rows; and a measurement module coupled with the plurality of rows of image sensor elements to measure the sharpness of detected image elements sensed by the image sensor elements in each row.

1 . An imaging apparatus comprising: 
 a plurality of rows of image sensor elements spaced from each other, extending in a first direction, and being configured to sense a set of image elements of a target moving in the first direction, to integrate light from the rows of image sensor elements into corresponding pixel values, and to shift the pixel values along the rows of image sensor elements in the first direction according to a clock rate, the plurality of rows having the same number of image sensor elements, each row having image sensor elements that are different in length from the image sensor elements of the other rows; and    a measurement module coupled with the plurality of rows of image sensor elements to measure the sharpness of detected image elements sensed by the image sensor elements in each row.    
   
   
       2 . The imaging apparatus of  claim 1  further comprising a controller configured to control a velocity of the target based on the measured sharpness of the detected image elements of the rows of image sensor elements.  
   
   
       3 . The imaging apparatus of  claim 1  wherein the velocity of movement of the target is determined based on the sharpest detected image elements.  
   
   
       4 . The imaging apparatus of  claim 1  further comprising a two- dimensional array of image sensor elements being configured to sense another set of image elements of the target moving in the first direction with respect to the two-dimensional array of image sensor elements, to integrate light from the set of image elements into corresponding pixel values, and to shift the pixel values along the image sensor elements of the two-dimensional array in the first direction according to the clock rate.  
   
   
       5 . The imaging apparatus of  claim 4  wherein the image sensor elements in one of the plurality of rows of image sensor elements are equal in length to the image sensor elements of the two-dimensional array.  
   
   
       6 . The imaging apparatus of  claim 4  comprising at least three rows of image sensor elements spaced from each other, wherein the image sensor elements in at least one of the rows are long image sensor elements which are greater in length than the image sensor elements of the two-dimensional array, and wherein the image sensor elements in at least one of the rows are short image sensor elements which are smaller in length than the image sensor elements of the two-dimensional array.  
   
   
       7 . The imaging apparatus of  claim 6  wherein output from the at least three rows of image sensor elements are used to determine the velocity of movement of the target.  
   
   
       8 . The imaging apparatus of  claim 6  wherein the long image sensor elements are greater in length than the image sensor elements of the two-dimensional array of image sensor elements by at most about 30%, and wherein the short image sensor elements are smaller in length than the image sensor elements of the two-dimensional array of image sensor elements by at most about 30%.  
   
   
       9 . The imaging apparatus of  claim 6  wherein the image sensor elements in one of the rows are reference image sensor elements which are equal in length to the image sensor elements of the two-dimensional array.  
   
   
       10 . The imaging apparatus of  claim 9  further comprising a controller configured to control either the velocity of the target moving in the first direction or the clock rate of shifting the charge packets along the image sensor elements of the two-dimensional array in the first direction, wherein the controller makes no adjustment if the row of reference image sensor elements have the sharpest detected image elements, wherein the controller increases the velocity of the target or decreases the clock rate if the row of short image sensor elements have the sharpest detected image elements, and wherein the controller decreases the velocity of the target or increases the clock rate if the row of long image sensor elements have the sharpest detected image elements.  
   
   
       11 . The imaging apparatus of  claim 10  wherein the controller is configured to adjust the velocity of the target or the clock rate by interpolation or extrapolation based on differences in lengths of the sensor elements among the plurality of rows and the sharpness of the detected image elements by the plurality of rows of image sensor elements as sensed by the measurement module.  
   
   
       12 . The imaging apparatus of  claim 1  wherein the plurality of rows of image sensor elements are closely spaced from each other.  
   
   
       13 . The imaging apparatus of  claim 1  wherein the measurement module comprises a plurality of correlation circuits each coupled with one of the plurality of rows of image sensor elements to measure the sharpness of the detected image elements sensed by the image sensor elements in each row.  
   
   
       14 . The imaging apparatus of  claim 13  wherein the measurement module comprises a comparison module configured to compare the sharpness measured by the plurality of correlation circuits and identify the row of image sensor elements having the sharpest detected image elements.  
   
   
       15 . A method for optical imaging, comprising: 
 projecting a portion of an image of a target moving in a first direction onto a plurality of rows of image sensor elements spaced from each other and extending in the first direction, the plurality of rows having the same number of image sensor elements, each row having image sensor elements that are different in length from the image sensor elements of the other rows;    shifting the pixel values along the image sensor elements of the plurality of rows in the first direction according to a clock rate, each image sensor element of the plurality of rows continuing to integrate light projected thereon into the pixel value shifted therealong; and    measuring the sharpness of detected image elements sensed by the image sensor elements in each row of image sensor elements.    
   
   
       16 . The method of  claim 15  further comprising identifying the row of image sensor elements having the sharpest detected image elements sensed by the image sensor elements.  
   
   
       17 . The method of  claim 16  further comprising determining the velocity of movement of the target based on the sharpest detected image elements.  
   
   
       18 . The method of  claim 15  further comprising: 
 projecting another portion of the image of the target moving in the first direction onto a two-dimensional array of image sensor elements which are configured to integrate light from the image into corresponding pixel values; and    shifting the pixel values along the image sensor elements of the two- dimensional array in the first direction according to the clock rate, each image sensor element of the two-dimensional array continuing to integrate light projected thereon into the pixel value shifted therealong.    
   
   
       19 . The method of  claim 18  wherein at least three rows of image sensor elements are spaced from each other, wherein the image sensor elements in at least one of the rows are long image sensor elements which are greater in length than the image sensor elements of the two-dimensional array, wherein the image sensor elements in at least one of the rows are short image sensor elements which are smaller in length than the image sensor elements of the two-dimensional array, and wherein the image sensor elements in one of the rows are reference image sensor elements which are equal in length to the image sensor elements of the two-dimensional array.  
   
   
       20 . The method of  claim 19  further comprising determining the velocity of movement of the target based on output of the at least three rows of image sensor elements.  
   
   
       21 . The method of  claim 18  further comprising controlling either the velocity of the target moving in the first direction or the clock rate of shifting the charge packets along the image sensor elements of the two-dimensional array in the first direction, wherein no adjustment is made if the row of reference image sensor elements have the sharpest detected image elements, wherein the velocity of the target is increased or the clock rate is decreased if the row of short image sensor elements have the sharpest detected image elements, and wherein the velocity of the target is decreased or the clock rate is increased if the row of long image sensor elements have the sharpest detected image elements.  
   
   
       22 . The method of  claim 21  wherein adjusting the velocity of the target or clock rate comprises interpolating or extrapolating the sharpness of the detected image elements by the plurality of rows of image sensor elements based on differences in lengths of the sensor elements among the plurality of rows.  
   
   
       23 . An imaging apparatus comprising: 
 a plurality of CCD shift registers each including a plurality of image sensor elements extending in a first direction to generate charge packets from a set of image elements of a target projected on the image sensor elements of the CCD shift registers and moving in the first direction, and to shift the charge packets along the image sensor elements in the first direction according to a clock rate, the plurality of CCD shift registers having the same number of image sensor elements, each CCD shift register having image sensor elements that are different in length from the image sensor elements of the other CCD shift registers; and    a measurement module coupled with the plurality of CCD shift registers to measure the sharpness of detected image elements sensed by the image sensor elements in each CCD shift register.    
   
   
       24 . The imaging apparatus of  claim 23  wherein the measurement module is configured to identify the CCD shift register having the sharpest detected image elements sensed by the image sensor elements.  
   
   
       25 . The imaging apparatus of  claim 24  wherein the velocity of movement of the target is determined based on the sharpest detected image elements.  
   
   
       26 . The imaging apparatus of  claim 23  further comprising a two- dimensional CCD array of image sensor elements being configured to generate charge packets from another set of image elements of the target projected on the image sensor elements of the CCD array and moving in the first direction with respect to the CCD array of image sensor elements, and to shift the charge packets along the image sensor elements in the first direction according to the clock rate.  
   
   
       27 . The imaging apparatus of  claim 26  further comprising a controller configured to control either the velocity of the target moving in the first direction or the clock rate of shifting the charge packets along the image sensor elements of the CCD array in the first direction based on the measured sharpness of the detected image elements of the CCD shift registers.  
   
   
       28 . The imaging apparatus of  claim 27  wherein at least three CCD shift registers are spaced from each other, wherein the image sensor elements in at least one of the CCD shift registers are long image sensor elements which are greater in length than the image sensor elements of the two-dimensional array, wherein the image sensor elements in at least one of the CCD shift registers are short image sensor elements which are smaller in length than the image sensor elements of the two-dimensional array, and wherein the image sensor elements in one of the CCD shift registers are reference image sensor elements which are equal in length to the image sensor elements of the two-dimensional array.  
   
   
       29 . The imaging apparatus of  claim 28  wherein output from the at least three CCD shift registers are used to determine the velocity of movement of the target.  
   
   
       30 . The imaging apparatus of  claim 28  wherein the controller makes no adjustment if the row of reference image sensor elements have the sharpest detected image elements, wherein the controller increases the velocity of the target or decreases the clock rate if the row of short image sensor elements have the sharpest detected image elements, and wherein the controller decreases the velocity of the target or increases the clock rate if the row of long image sensor elements have the sharpest detected image elements.