For red, green and blue OLEDs that emit for
each of them in a wide spectral range ($\Delta \lambda \approx 200$
nm), we calculate the luminous luminance, the energetic luminance and the
various yields in the pseudo-monochromatic hypothesis (ideal source
generally considered), and we compare with a calculation in relation with a
polychromatic system (real source). Finally, we demonstrate that the values
of the energetic luminance and of the energetic or quantum yield are
practically unchanged whatever the hypothesis; on the contrary, in the
simplified case of the pseudo-monochromatic source, the luminous luminance
and the luminous yield of a green organic diode are overvalued in relation
to the polychromatic real case, whereas for a blue or a red organic diode
these parameters (calculated in the pseudo-monochromatic hypothesis) are
undervalued. The error is all the more great since the OLED emission is far
away from the maximum value of the photoptical eye response.