An image quality on a recording material is influenced by, for example, the sensitivity of a developer for use in developing the recording material. Moreover, the endoscope apparatus according to the present invention can improve the maneuverability of the insert portion and applicator during pull-in operation. Thus, a fair profit redistribution can be easily performed. In addition, cut off wavelength is increased to just below the operating window. The arrays are then listed in a graphical user interface. The optical transmitter of the invention includes a controller configured to read initial parameters from the memory, to increase the bias and modulation currents in stepwise based on thus read initial parameters, and to begin the automatic feedback control to keep the optical output from the laser diode constant after the bias and modulation currents reach their temporarily target values.