Ricoh, historically, used the Pentax K-mount for their film SLR cameras, but with a slight and important modification: they added a pin that's used to indicate the aperture is in auto mode for shutter priority use. With some careful work, you can remove the pin for use on K-mount bodies made by Pentax or Samsung or with a K to EF adapter for Canon EOS digital and film variants. Nevertheless, if you have Ricoh K-mount lenses (with the P setting), then that pin has to go.
You can confirm if you have these based on this helpful bit of info from Wikipedia: The R-K mount is used on Rikenon P lenses, Ricoh bodies that include the letter 'P' in their model number, and some non-Ricoh lenses.
Now, it's also possible that the Ricoh lenses are M42 screw-mount lenses also known, funny enough, as the Pentax mount when most film cameras had it and Pentax was the SLR king. If that is the case, and it's easy to tell by just looking for threads on the lens mount, then you can easily get adapters for it for a variety of cameras including your Canon option.
On the ironic side, Pentax is now owned by Ricoh...