[Devel] Re: Patents will expire...?

[David Turner]

Hello Tony,

Tony Mobily a écrit :
> 
> Hi David,
> 
> did you check when the patents:
> 
> Patent #1 : US5155805: Method and apparatus for moving control points in
> displaying digital typeface on raster output devices
> 
> Filed on May, 8 1989
> 
> Patent #2 : US5159668: Method and apparatus for manipulating outlines in
> improving digital typeface on raster output devices
> 
> Filed on May, 8 1989 too. Actually, the two patents were filed and granted
> concurrently.
> 
> Patent #3 : US5325479: Method and apparatus for moving control points in
> displaying digital typeface on raster output devices
> 
> Filed on May 28, 1992
> 
> ...will expire?
> It's going to be 10 years soon, and...
>

Add 20 years to the filing date. This means that patents #1 and #2 will
expire on May, 8, 2009 (in about 7 years from today)

I ahve finely analyzed the patent and I'd like to remark the following:

  Patent #1 protects the _exact_ computation performed by a MIRP instruction.
  (basically a dot-product in 2D space, yekk..)

  Patent #3 protects _approximations_ of this computation, since these might
  generate an outline that is slightly different, but still produce correct
  bitmaps !! FreeType doesn't infringe on it, by the way..
 
Seems Apple really wanted to "lock" the use of TrueType :-)


Cheers,

- David Turner