All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If the women can follow the lecture by listening directly from the place that is allotted to them, then there is no need to broadcast such lectures through TV screens as this might lead to temptation. Indeed, some women might be tempted by the men they see on screen and this can have bad consequences. This is one of the reasons many scholars believe that watching TV in general is not lawful. Ibn Katheer said in his explanation of the following verse: {And tell the believing women to lower their gaze (from looking at forbidden things),…} [Quran 24:31], 'Women should not look at that which Allah has forbidden to them; i.e., looking at non-Mahram men. For this reason, many scholars believe that it is unlawful for a woman to look at non-Mahram men whether it is with desire or without desire.” But if there is no fear of temptation and there is a need to see the lecture on TV screens because the lecturer uses some aids that make things clearer, then there is no objection to doing so.
Allah knows best.