I read a few threads explaining how to drive a 1-digit (7-segment) LED correctly. After all, most threads recommend that I should connect 1 resistor for each segment (which make it the total of 8 resistors) rather than using only 1 resistor for all of them. Now I agree with this view-point, as the characteristic of each LED is different and therefore using only 1 resistor may result in uneven brightness and other issues.
However, when I think about the case of driving a 4-digit (7-segment) LED. The problem seems to repeat itself.
With the above 4-digit LED, each segment is connected to one common pin. For example, all 4 A-segment are connected to pin number 11. Since I can only wire 1 resistor to this pin, this turn out to be the case of 1 resistor for 4 parallel LED again!
So I wonder how can I drive this 4-digit LED correctly without causing uneven brightness in any segment at all? Moreover, I exclude the case we use 4 separate 1-digit LED because that results in too much pinouts and resistors.