Our Procedures our viewed electronically and the version that we see has blank spots where the approval signatures should be. Should we be viewing the copy that shows who approved them and the dates?

Our Procedures our viewed electronically and the version that we see has blank spots where the approval signatures should be. Should we be viewing the copy that shows who approved them and the dates?
It's not necessary, so long as there's a control mechanism in place that insures that the viewed copies are always the same as the controlled (approved) copies.

We convert all our MS-word document into PDF file, so that no one can alter the document. Secondly, we have scanned the signature of "authority" and insert into the PDF file.

Before we implemented above procedure, we typed "signed-off copy available" where the approval signature should be.

Both good answers. The main things are to ensure that the latest copy is what is available and there are measures in place that prevent unauthorized tampering. When you make sure that whomever needs access to the documents has it, you then have this issue closed.

Actually, the Standard is silent on this issue. Some regulatory body for certain industries may make this an issue, but for the most part, duplicating the actual holograph signature of the approver is not necessary in electronic document management, especially if you have a system of checks and balances to assure an audit trail to identify authors and approval signatories by their log in password. In point of fact, a handwritten signature is not required in the Standard - a typed one would do as well. The main point is for the organization to assure the document went through the approval process and that it is the most recent approved copy. That assurance is not the burden of the document reader.

In the case where the document is simply a scanned copy of a hard document into a locked pdf file, why not take the picture of the signature as well?

Think of it this way: will most document users and readers be able to decipher and identify the signature as belonging to a person actually having approval authority? Will they be able to detect a forgery? Is it necessary? If I'm in a 50 person company, probably yes. If I'm a machine operator in a multinational of tens of thousands of employees, would I have a clue?

The Standard always makes allowance for what makes sense for the organization, not what fits the Standard.

It depends on the system you have in place for doc control. When we were still all paper, we wrote into our system a signature hand-off for documents. Now that we have an electronic system that has its own system for raising change requests and approval of changes, we use this in our qms and have no signatures at all. If you are electronic but do not have an elaborate system, you could still keep from signatures by using email.