Many people probably had not forgotten that, during the last battle against the Fear Laughing Demon in the Dream, Schiller had used the ring's properties to amplify certain aspects of Victor, Gordon, and the others' emotions, thereby drawing rings of many different colors.
As mentioned before, because the battle had taken place in a dream, the rings that had been summoned discovered that the hosts they wanted to bond with were unconscious. During the bonding process, if they did not receive a positive response from the person, they would not leave directly.
Thus, the rings abandoned their physical forms and sent their energy into the hosts' bodies, intending to awaken their consciousness. In doing so, they entered the dream space where the battle against the Fear Laughing Demon was taking place and provided energy for the group.
However, the physical rings had remained outside. Having lost their energy, they became ordinary metal rings and could no longer return to the Lantern Corps.
After the battle ended, each of the people who woke up found a brightly colored metal ring beside them. Schiller had warned them beforehand, so they collected the rings and eventually handed them over to Schiller.
Schiller had no interest in the rings. In his view, the so-called "Emotional Spectrum" was about as reliable as using naive materialism to explain the truth of the world. So he stuffed all the rings into a box and tossed it to Batman.
As everyone knew, once anything entered the Batcave as part of Batman's collection, not even God himself could get it back.
When Batman poured that box of rings onto the table, Hal's eyes nearly popped out of his head. Having worn a Green Lantern ring for so long, he could naturally tell that these were not counterfeit souvenirs, but