Ex parte GOTO - Page 4

            Appeal No. 95-2948                                                                                                     
            Application 07/833,664                                                                                                 

            superposition of two driving signals, one being in a high frequency range, typically about 50-200                      
            Hz, and the other within a low frequency range, typically about 5-100 Hz.  The reflector oscillates                    
            at a medium-high frequency, about 50-200 Hz, in the x-z plane (torsional mode) and at a low                            
            frequency, about 20-30 Hz, in the x-y plane (bending mode).  The scanner structure in figures 6a                       
            and 6b of Dvorkis is similar to appellant's scanner in figure 1 except that appellant's drive source                   
            is coupled to the end of the deformable shaft opposite the reflector.                                                  
                    Bard discloses a hand held bar code reader which use one or more piezoelectric bimorph                         
            elements in the scanning function of the bar code reader optical system.  A piezoelectric bimorph                      
            element comprises two layers bonded together with a conductive medium with conductive material                         
            also on the outside surfaces.  When a voltage is applied the device bends and when the voltage is                      
            reversed the device bends in the opposite direction (column 6, lines 26-40).  Bard states that                         
            piezoelectric actuators can operate at high frequencies "but have a technical disadvantage of a very                   
            small magnitude of mechanical displacement" (column 2, lines 53-56).  "Larger displacements are                        
            also possible when the frequency of the drive signal equals the mechanical resonance frequency                         
            of the piezoelement" (column 2, line 67 to column 3, line 1).  "FIG. 8 depicts a bar code scanning                     
            optical system having a pair of sequentially mounted piezoelectric bimorphs, a first bimorph 46                        
            for y deflection and a second bimorph 48, mounted on the first bimorph 46, for x deflection, which                     
            drives a scanning mirror 50 for combined x and y deflections of the scanned beam" (column 7,                           
            lines 45-50).                                                                                                          

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