| 摘要 |
PURPOSE:To secure the reliability of printing quality by keeping the viscosity of ink and a density range almost constant, by constituting the titled apparatus so that a diluted solution is injected in an ink sump part corresponding to the output signal of a sensor detecting the evaporation quantity of moisture in ink on the basis of the change in the output level of a light receiving element. CONSTITUTION:A moisture evaporation ratio sensor consisting of a fiber 121, a light emitting element 122 and a light receiving element 123 is provided in an ink liquid chamber 42. The light emitting element 122 introduces a definite quantity of light into the fiber 121. The light passing through the fiber 121 is received by a light receiving element 123 and detected through a photodetector 125, an amplifier 126 and a level detector 127 to be supplied to CPU. When the moisture evaporation ratio sensor detects that the moisture evaporation ratio of the ink in the ink liquid chamber 42 exceeds a reference value, the diluted solution in a dilution tank is injected in the ink liquid chamber 42 and, when said evaporation ratio reaches the reference value of less, by approving printing, the reliability of printing quality can be secured. |
