| 摘要 |
PURPOSE:To obtain a high-quality negative, by stopping the developing treatment when the ratio of the receiving intensity of the laser light transmitted through a bit forming part to that through a part, where bits are not formed, on the negative reaches a prescirbed value. CONSTITUTION:The light incident to a negative 2 is transmitted there and is made incident to a lower photoelectric transducer 10 when bits are not formed. When bits are formed, a part of the incident light is diffracted by bits and is made incident to a photoeletric transducer 11. Electric outputs of transucers 10 and 11 are amplified and are inputted to an operator 12. The output signal of the operator 12 which indicates the ratio of the quantity of receiving light of the transducer 10 to that of the transducer 11 is inputted to a comparator 13 and is compared with a reference signal Vr. The comparator 13 generates a developing treatment stop signal when the output of the operator 12 reaches the level of the signal Vr. When receiving this signal, a controlling circuit 14 excites valve driving motors 15 and 16 to terminate the developing treatment. Thus, a high-quality negative is obtained without the variance of bit dimensions in each negative. |
