Efficient method and apparatus for downloading of fonts from a processor to a printer

• US 5,729,666 A
• Filed: 08/05/1996
• Issued: 03/17/1998
• Est. Priority Date: 08/05/1996
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Konsella, Shane, Gunning, Chris R.
• Primary Examiner(s): Evans, Arthur G.
• Application Number:
  US08/692,662
• Time in Patent Office: 589 Days
• Field of Search: 395/110, 395/114, 395/115, 395/117, 395/101, 395/167, 395/171, 395/172, 395/885, 395/892, 395/894, 400/70, 400/71, 400/76, 358/470
• US Class Current: 358/1.11
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 2215/0008 Downloading generic data

Abstract

A data processing configuration includes a computer, a printer and a font memory which houses tables that define spacing metrics that are individual to each glyph included in a font. The computer is connected to the font memory and further includes a printer driver function which is controllable to download glyph data to the printer in response to an output from an application, running on the computer, which specifies a requirement that a glyph is to be printed by the printer. The computer is responsive to a download requirement to derive from the font memory, header data for transmission to the printer. The downloaded header data excludes the spacing metrics that are individual to each glyph of the font. Thereafter, the printer driver downloads required font glyph data by transmitting data structures to the printer which include, among other data elements, the spacing metrics that are individual to the specific glyph being transmitted. In such manner, spacing metrics are transmitted to the printer only with a particular associated glyph and only when that glyph is required at the printer, thereby reducing data transfer times and making more efficient use of printer memory.

Claims

1. A data processing apparatus comprising:

a font memory including font header data which includes data which defines spacing metrics for each glyph stored in said font memory;

a printer; and

a host processor coupling said font memory to said printer and further including printer driver means for enabling communications with said printer, said printer driver means downloading said font header data to said printer when a first glyph of a corresponding font is downloaded thereto, said font header data excluding said data which defines spacing metrics except for said first glyph and, in response to a requirement to download a further selected font glyph to said printer, downloading a glyph data structure corresponding to said further selected font glyph, said glyph data structure including said spacing metric data for only said further selected font glyph.

2. The data processing apparatus as recited in claim 1, wherein said spacing metric data comprises left side bearing and advance width data.

4. The data processing apparatus as recited in claim 1, wherein said font memory stores TrueType font data which comprises contour descriptions of font glyphs.

3. The data processing apparatus as recited in claim 3, wherein said font header data is devoid of left side bearing and advance width data for glyphs comprising said font.

5. A method for downloading font data from a host processor to a printer, said host processor including a font memory for storing font header data which includes data which defines spacing metrics for each glyph in a font, said host processor further including printer driver means for enabling communications between said host processor and said printer, said method comprising the steps of:

a) responding to a requirement to download a first glyph of a selected font to said printer, by

i) downloading font header data, excluding said data which defines spacing metrics for each said glyph in said font except for said first glyph to said printer; and

ii) downloading to said printer, a glyph data structure corresponding to said first glyph, said glyph data structure including spacing metric data for only said first font glyph; and

b) responding to a requirement to download a further glyph of said font to said printer, by downloading a glyph data structure corresponding to said further glyph, said glyph data structure including spacing metric data for only said further glyph.

6. The method as recited in claim 5, wherein said spacing metric data comprises left side bearing and advance width data.

7. The method as recited in claim 6, wherein said font header data is devoid of left side bearing and advance width data for glyphs comprising said font.

8. The method as recited in claim 5, wherein said font memory stores TrueType font data which comprises contour descriptions of font glyphs.