Large depth of field line scan camera

Abstract

A system for imaging an object comprising a surface for receiving the object to be imaged and an imaging device. The imaging device comprises a housing and a fixed focusing optical device mounted to the housing, whereby the fixed focusing optics comprises a lens for focusing light reflected from the object. A plurality of independent linear imaging sensors are positioned in the housing at different distances from the fixed focusing lens so that a face of each of the plurality of independent linear imaging sensors is aligned parallel to the surface. A processor is coupled to the plurality of independent linear imaging sensors for receiving an output signal from each of the plurality of independent linear imaging sensors representative of the reflected light. The lens defines a plane parallel to the surface, and the plurality of independent linear imaging sensors are adapted to receive reflected light from the object.

1 . A system for imaging an object comprising: 
 a. a surface for receiving an object to be imaged; and    b. an imaging device comprising: 
 i. a housing;  
 ii. a fixed focusing optical device mounted to said housing and comprising a lens for focusing light reflected from the object on said surface, said lens defining a plane parallel to said surface;  
 iii. a plurality of independent linear imaging sensors positioned in said housing at different distances from said fixed focusing lens so that a face of each of said plurality of independent linear imaging sensors is aligned parallel to said lens plane, wherein said plurality of independent linear imaging sensors are adapted to receive said reflected light from the object on said surface; and  
   c. a processor coupled to said plurality of independent linear imaging sensors receives an output signal from each of said plurality of independent linear imaging sensors representative of said reflected light.    
   
   
       2 . The system for imaging an object of  claim 1 , wherein said processor reads said output signal from said plurality of independent linear imaging sensors and selectively stores the data from one of said plurality of imaging sensors based on an intensity of light received by each of said plurality of independent linear imaging sensors, wherein said intensity of light is directly related to an amplitude of said output signal from each of said plurality of independent linear imaging sensors.  
   
   
       3 . The system for imaging an object of  claim 1 , further comprising a plurality of light sources mounted in said housing proximate said fixed focusing optical device for illuminating at least one surface of the object placed on said surface.  
   
   
       4 . The system for imaging an object of  claim 1 , wherein said plurality of independent linear imaging sensors are located at distances from said lens plane such that a plane intersecting each linear row of pixels for each of said plurality of independent linear imaging sensors intersects said lens plane at the Sheimpflug angle such that the focal point of each of said plurality of independent linear imaging sensors differ with respect to said surface.  
   
   
       5 . The system for imaging an object of  claim 1 , further comprising a height measuring device for detecting a height of the object on said surface prior to reaching said imaging device, wherein said detected height is used by said processor for selectively reading said output signal from one of said plurality of independent linear imaging sensors.  
   
   
       6 . The system for imaging an object of  claim 1 , wherein said processor forms a two-dimensional image from said output signals of said plurality of independent linear imaging sensors.  
   
   
       7 . The system for imaging an object of  claim 1 , wherein said processor is adapted to read an output signal from individual pixels located in a different one of said plurality of independent linear imaging sensors based on an intensity of said output of said individual pixels.  
   
   
       8 . The system for imaging an object of  claim 1 , wherein said surface is moveable in a direction perpendicular to an axis of each of said plurality of independent linear imaging sensors.  
   
   
       9 . A system for imaging an object comprising: 
 a. a surface for receiving an object to be imaged; and    b. an imaging device comprising: 
 i. a housing;  
 ii. a plurality of independent linear imaging sensors being positioned in said housing so that a face of each of said plurality of independent linear imaging sensors is parallel to said surface, said plurality of independent linear imaging sensors being adapted to receive reflected light from the object on said surface; and  
 iii. a fixed focusing optical device mounted to said housing and comprising a single lens for focusing said reflected light from the object on said surface onto each of said plurality of independent linear imaging sensors;  
   c. a processor coupled to said plurality of independent linear imaging sensors for reading an output signal from each of said plurality of independent linear imaging sensors.    
   
   
       10 . The system for imaging an object of  claim 9 , wherein said single lens is an irregular lens that provides a plurality of focal lengths each corresponding to a respective one of said plurality of independent linear imaging sensors.  
   
   
       11 . The system for imaging an object of  claim 9 , further comprising a plurality of linear actuators for independently moving each of said plurality of independent linear imaging sensors with respect to said fixed focusing optical device.  
   
   
       12 . The system for imaging an object of  claim 11 , further comprising a height measuring device for detecting a height of the object on said surface prior to reaching said imaging device, wherein said detected height is used by each of said plurality of linear actuators for moving each of said plurality of independent linear imaging sensors with respect to said fixed focusing device.  
   
   
       13 . The system for imaging an object of  claim 12 , further comprising a feedback loop from said processor to each of said plurality of linear actuators to assist in positioning each of said plurality of independent linear imaging sensors.  
   
   
       14 . The system for imaging an object of  claim 13 , wherein said processor is adapted to read an output signal from individual pixels located in a different one of said plurality of independent linear imaging sensors based on an intensity of said output of said individual pixels.  
   
   
       15 . The system for imaging an object of  claim 10 , further comprising a height measuring device for detecting a height of the object on said surface prior to reaching said imaging device, wherein said detected height is used by said processor for selectively reading said output signal from one of said plurality of independent linear imaging sensors.  
   
   
       16 . A system for imaging an object comprising: 
 a. a surface for receiving an object to be imaged; and    b. an imaging device comprising: 
 i. a housing;  
 ii. a fixed focusing optical device mounted to said housing and comprising a lens for focusing light reflected from the object on said surface, said fixed focusing optical device lens defining a plane parallel to said surface;  
 iii. a linear imaging sensor positioned in said housing radially outward from an axis normal to said plane;  
 iv. first and second mirrors rotatably coupled to a pivot axis and positioned so as to direct light entering said fixed focusing optical device onto said linear imaging sensor; and  
   c. a processor coupled to said linear imaging sensor for reading an output signal from individual pixels in said linear imaging sensor based on an intensity of said output signal from each of said individual pixels,    wherein each of said first and said second mirrors are independently moveable about said pivot axis along a path generally perpendicular to said linear image sensor with respect to each other so that different portions of said surface can be focused onto different portions of said linear sensor.    
   
   
       17 . The system for imaging an object of  claim 16 , further comprising a first and second actuator for respectively rotating said first and second mirrors about said pivot axis with respect to said linear imaging sensor.  
   
   
       18 . The system for imaging an object of  claim 17 , further comprising third and fourth actuators for respectively translating said first and said second mirrors along said pivot axis with respect to said lineal imaging sensor.  
   
   
       19 . The system for imaging an object of  claim 16 , further comprising a third mirror rotatably coupled to said pivot axis and positioned so as to direct light entering said fixed focusing optical device onto said linear imaging sensor.  
   
   
       20 . The system for imaging an object of  claim 16 , further comprising a height measuring device for detecting a height of the object on said surface, wherein said detected height information is used by said first and said second actuators for moving each of said first and second mirrors to focus on the object on said surface.