Portable instrument for electro-optically reading indicia and for projecting a bit-mapped color image

Abstract

A portable instrument incorporates an electro-optical assembly for reading indicia during a reading mode, and for projecting a bit-mapped color image during a display mode. A manually operable switch on the instrument is disposed for selecting one of the modes. The color image is formed by pulsing a plurality of differently colored lasers at selected times on selected scan lines.

1 - 17 . (canceled)  
   
   
       18 . An image projection arrangement for projecting a two-dimensional image, comprising: 
 a) an energizable light source for generating a light beam when energized;    b) a scanner operative at an operating power for sweeping the light beam at a scan angle and at a scan rate in a pattern of scan lines across a viewing surface, each scan line having a number of pixels; and    c) a controller operatively connected to the scanner and the light source, for causing selected pixels to be illuminated, and rendered visible, by the light beam to produce the image having a display area on the viewing surface, and for varying the display area as a function of at least one of the scan angle, the scan rate, and the operating power of the scanner.    
   
   
       19 . The arrangement of  claim 18 , wherein the light source is a laser, and wherein the light beam is a laser beam.  
   
   
       20 . The arrangement of  claim 18 , wherein the scanner includes a first scan mirror for sweeping the light beam along a first direction, and a second scan mirror for sweeping the light beam along a second direction generally orthogonal to the first direction.  
   
   
       21 . The arrangement of  claim 18 , and a support for supporting the light source, the scanner and the controller.  
   
   
       22 . The arrangement of  claim 18 , wherein the pattern of scan lines is a raster pattern.  
   
   
       23 . The arrangement of  claim 18 , wherein the controller is operative for pulsing the light source on and off while the light beam is swept over each of the scan lines.  
   
   
       24 . The arrangement of  claim 18 , wherein the scan rate is at a minimum of 40 Hz to reduce flicker.  
   
   
       25 . The arrangement of  claim 20 , wherein at least one of the mirrors is a planar mirror mounted for oscillation about an axis extending along a centerline of the planar mirror.  
   
   
       26 . The arrangement of  claim 18 , and means for blocking the scan lines at a top and a bottom of the pattern to reduce distortion due to variation of the scan rate.  
   
   
       27 . A method of projecting a two-dimensional image, comprising the steps of: 
 a) energizing a light source for generating a light beam;    b) sweeping the light beam at a scan angle and at a scan rate in a pattern of scan lines across a viewing surface by operating a scanner at an operating power, each scan line having a number of pixels; and    c) causing selected pixels to be illuminated, and rendered visible, by the light beam to produce an image having a display area on the viewing surface, and varying the display area as a function of at least one of the scan angle, the scan rate, and the operating power of the scanner.    
   
   
       28 . The method of  claim 27 , wherein the light source is a laser, and wherein the light beam is a laser beam.  
   
   
       29 . The method of  claim 27 , wherein the sweeping step is performed by a first scan mirror for sweeping the light beam along a first direction, and a second scan mirror for sweeping the light beam along a second direction generally orthogonal to the first direction.  
   
   
       30 . The method of  claim 27 , wherein the pattern of scan lines is a raster pattern.  
   
   
       31 . The method of  claim 27 , and pulsing the light source on and off while the light beam is swept over each of the scan lines.  
   
   
       32 . The method of  claim 29 , wherein the scan rate is at a minimum of 40 Hz to reduce flicker.  
   
   
       33 . The method of  claim 29 , and the step of mounting at least one of the mirrors for oscillation about an axis that extends along a centerline of the at least one mirror.  
   
   
       34 . The method of  claim 27 , and the step of blocking the scan lines at a top and a bottom of the pattern to reduce distortion due to variation of the scan rate.