Why is Ic constant in the plot of Vce vs Ic in a common emitter NPN transistor (in active region)?

In this plot, when $$\V_{ce}\$$ increases in the active region, shouldn't $$\I_c\$$ also increase as more electrons are getting diffused into the collector?

Then, why is it that for a large range of $$\V_{ce}\$$ , $$\I_c\$$ doesn't seem to change at all?

• Because the base collector depletion region widens with more collector voltage. – Andy aka Dec 15 '18 at 20:47