SharePoint People Search Results gives "Domain\Account" Instead of User Display Name

Problem:
SharePoint 2010 people search gives "Domain\AccountID" instead of Display name of the user!


Solution:
SharePoint uses "Preferred Name" property which is mapped with "Display Name" property from AD in People search results. Here, I found the root cause of the problem as: User profile not in sync!

Steps to resolve:

• Make sure in AD, display name field is set properly
• Go to SharePoint central Administration >> Do a full profile import. 
• Once you run full profile import, You should see the display name field updated  in user profiles.
• Run SharePoint search incremental crawl once for the search results to get updated.