Hearn recently rewarded manager Russell Slade for guiding the O's to two seventh-placed finishes in three seasons with a two-year contract extension.
And Hearn is backing Slade to mount a genuine bid to reach the Championship next term.
"Finishing seventh two years out of three, I think we would normally bite peoples arms off at that, so we're now getting a bit ambitious," he told the club website.
"We're now thinking 'okay that's great but what's the next level?' The next level is to try and get into the Championship and that's what we're going to try and do this year."