摘要 |
FIELD: physics. ^ SUBSTANCE: in the reading method, light modulation frequency is changed in accordance with the selected linear speed. The light modulation frequency is equal to the ratio of peak power to average laser beam reading power. For two linear reading speed values, the second of which is double the first, the second average reading power is higher than the first average reading power, and the second light modulation frequency is lower than the first light modulation frequency. ^ EFFECT: high signal-to-noise ratio of reading. ^ 2 cl, 6 dwg |