Abstract: A bar code reading method and apparatus. Comparison reference values are calculated based upon actual measurements of the width of bars and spaces which comprise the bar code pattern and upon a prestored constant. The measured bar and space widths are compared to the reference values to determine the information represented by the bar code. Since the reference values are generated from the measured values of the bars and spaces the scanning speed is irrelevant and errors are avoided. Similarly, minor width variations, caused by inaccurate printing, between like bars or spaces do not affect reading results.

Abstract: Bar code reading method and apparatus which is insensitive to scanning speed and to minor variations in width, caused by inaccurate printing, between like bars and spaces and which is suitable in particular to hand held manual scanners. The width of all the bars and spaces in a bar code are measured and stored in a memory. Selected ones of the stored measured width values are summed up to provide one or more sum values. For each bar and space whose binary status "0" or "1" is to be determined, a respective quotient is generated by dividing one of the stored sum values by the measured width of the bar or space whose binary status is being determined. The quotient, thus obtained, is compared to a prestored reference constant and on that basis the binary status of the bar or space is ascertained.

Abstract: A method is described for preparing a magnetic recording medium by vapor-depositing a magnetic metal thin film on a polyester film, which comprises winding up a polyester film while subjecting the polyester film to a tension of from 0.1 to 2.0 kg/mm.sup.2, heating the resulting polyester film roll at 60.degree. C. to 80.degree. C. for from 10 to 100 hours, and vapor-depositing a magnetic thin film onto the polyester film while subjecting the polyester film to a tension of 0.5 kg/mm.sup.2 or more.

Abstract: A dot matrix printer having a printer hammer bank carried on a frame to allow movement parallel to the platen. A balancing member is suspended from the head hammer bank by resilient springs and carries a motor for driving the head hammer bank in a reciprocating manner. A linkage further couples the head hammer bank and the balancing member so that the balancing member moves in a direction opposite to that of the head hammer bank.