pure black and white is called bitmap . It's zeros and ones, on or off, and unless you're doing VERY high resolution (1200 pixels per inch or more) scans, you're going to end up with jagged edges:
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as the program tries to decide what is an edge and to turn the angled edges into smooth lines. If you go vector, rather than pixel-based, you're either going to end up with tons of vector points to capture the detail or fewer points and less detail.
The devil is always trying to automate the decision of what is black and what is white. Too many shades of grey and too much purple and brown colors that read as black. Better men than I have bumped up against this problem. Greg Theakston takes his comic book pages and soaks them in a light bleach to eliminate the color and then scans them at high resolution for his reprint books. Bitmap web images are always a battle between size and clarity.
Good luck and let us know if you succeed. Just be aware that what you're trying to do is NON-trivial.
Peace, Jim (|:{>