1 is in relative motion with respect to the bar code 7 and the procedure goes to a step s 13 at the step s 13 all the data obtained so far is discarded and the procedure goes to the step s 1 to start a next read operation if the step s 5 indicates that another bar code is demodulated the procedure goes to a step s 6 where a check is made whether the bar codes demodulated at the steps s 1 and s 5 are obtained by the same scan e g scanned by the same scan beam scanning the same area this is an appropriate check point when the read operation requires that a particular beam be used for reading a bar code menu if the bar codes are not obtained by the same scan beam the procedure goes back to the step s 5 since required conditions for reading a bar code menu are not satisfied if the step s 6 indicates that the bar codes are obtained by the same scan beam the procedure goes to a step s 7 at the step s 7 a check is made whether the demodulated data of the step s 1 is the same as the demodulated data of the step s 5 this check is made based on a straightforward comparison between the two sets of data if the two sets of data are not the same this means that the bar code demodulated at the step s 1 is a different bar code from that of the step s 5 in.