RPR-220 photosensor to logic level?
In your original circuit any current flowing through the photo transistor will go into the base of the NPN transistor and turn it ON.

Answer - change the position of the resistor in the photo transistor circuit and increase its value.
To turn the NPN transistor ON we need to raise its base-emitter voltage to 0.6V. With a 22k resistor this require a current of about 27 microamps (about half your measured value). To increase sensitivity increase the value of this resistor but remember there is ambient light which may cause the opto transistor to turn on so there will be a limit on how large you can make this value.