http://revach.net/article.php?id=620

Section: Halacha   Category: Tshuvos
Do You Need To Learn Torah On Tisha B'Av?

Many poskim say that the Mitzva of Talmud Torah does not apply on Tisha B'Av and therefore you don't need to learn at all. If you do want to learn you may learn only things that are permissible, but this is optional. Others including the Sdei Chemed disagree and hold that the mitzva of Talmud Torah applies just like every day, but you may only learn things that are appropriate.