I have a 1941 US DIME with a crown mark no D or S marking. Is it just worn or is this something to research more?

The mint mark on a 1941 US dime would be located on the reverse [tails] side of the coin just to the right of the letter "E" in the Word "ONE". If the crown you asked about is on the obverse [heads] side of the coin just above and slightly to the right of the date, what you are seeing are the initials "AW" for the designer of the coin , Adolph A. Weinman. Wear on the dies used to make the coin sometimes gives this the appearance of a crown.