PS5 Rumored to Be Able to Play PS4 Games
At the beginning of 2022, rumors about the release of the PlayStation 5 were getting stronger. Although it has been tightly closed regarding information from the PS5, Sony doesn’t seem to be able to do that. This is evidenced by rumors circulating that the PS5 can play games from the PS4.
The report was obtained through Hokanko-Alt, based on that, Sony seems to have patented a novelty to Japanese Patent Office which is where a CPU can share software for the future. In a sense, the PS5 CPU can play games from the PS4.

However, the information above is still just a rumor. The reason, Sony has not provided related information about this.
Source: Hokanko Alt