  For any rank 2 Drinfeld module rho defined over an algebraic function field,
we consider its period matrix P, which is analogous to the period matrix of an
elliptic curve defined over a number field. Suppose that the characteristic of
F_q is odd and rho is without complex multiplication. We show that the
transcendence degree of the field generated by the entries of P over F_q(theta)
is 4. As a consequence, we show also the algebraic independence of Drinfeld
logarithms of algebraic functions which are linearly independent over
F_q(theta).
