SD Card Corrupted File

I have a San Disk 1GB SD Memory card I have used in a Vivitar 5100 Camera. I put the card into a HP Photosmart C4280 All-in-One Printer slot and it opened and I viewed the pictures. I then closed it because I did not have time to work with the pics at that time. Later I put SD card back in the All-in-One to copy pics to my hard drive and it said there were no images to view. File now says it is 4 seperate files - a ".HPIMAGE VFS File with 38.7MB used hidden archive", a .hpiamge vfs file with okb, a 5 file with no property type and 0 kb, and a vcpMISC file with no file typr and 1KB. Normally file shows as a folder called "DCIM" which opens to a folder called "100vivit" which opens to pics that are .jpeg images. Is there a way to recover my photos? Is there a way to keep this from happening again?