Can individual patents be converted into company patents?

You can apply in your own name, and then go to the patent office to handle the transfer procedures and transfer to the company.

Of course, if the applicant for this patent is also a legal person of the company, this may be a bit problematic, but you can apply for the patent in the name of others, then go through the transfer procedures, or take the patent as an intangible asset to become a shareholder.