ITherm® 280 Unicode and Fonts iTherm
®
280 Programmer’s Guide
Page 260 Rev C 28-07764
are always spaced in a fixed dot cell provided that the legacy commands are used. Adding or
subtracting space between characters achieves different character pitches with a fixed
character cell size. As each dot has a fixed size and position, only specific pitches are possible.
Character spacing may also be selected by requesting a print pitch based on characters pre
inch. Once again, the results are not exact.
If the requested spacing is zero, the character spacing will be defined by the character
definition, and will result in variable spacing.
Line spacing
The legacy commands select line spacing as lines per inch. With scalable characters, the lines
per inch is a minimum spacing. If a character is larger then the spacing between lines, the line
spacing will be increased to allow enough room for the characters on that line.
Selecting character size by points.
In addition to the legacy or classic method of character size selection, the ITherm 280 allows
selection by point size. Point sizes from 4 to 72 points may be selected for both the horizontal
and vertical axes. If a horizontal point size of zero (0) is selected for the horizontal spacing the
characters are printed using variable spacing based on the character definition, using the
vertical point size for the horizontal point size.
To provide fine control over character size, two commands are available, one of which specifies
the size in points, and the other of which specifies the size in ¼-point increments.
If the font is a stroke font, the boldness of the characters is controlled through variations in
individual stroke width.
Internal Fonts
The ITherm 280 is provided by default with a standard WGL4 outline-based font, and optionally
with an additional GB18030 stroke-based font. Additional user defined outline or stroke fonts
may be used as required.
The default font provided with the ITherm 280 is called “Andale Mono Regular” from Monotype.
This is a fixed-pitch font that produces good results when compared to legacy bitmap fonts. As
another alternative, the printer may be ordered with a variable-pitch font, which will allow
variable-pitch printing.
Character Cache
The ITherm 280 supports a high speed character cache that can cache character bitmaps,
outlines, tiles, or bands of characters. The caching technique is based on a least-recently used
(LRU) algorithm. The Cache contains an entry for each size of character used. The amount of
space in the cache used by each character is dependant on the size of the character.
At power up, the character cache is empty. The first ticket will require that all characters to be
printed be generated from the vector data. This will typically make the first ticket slightly slower
than subsequent tickets. It is also possible to define a user defined font with different metrics
that will cause the cache to be flushed when any of the user characters are being accessed. If
this should occur, the user defined font should be changed to match the other fonts in the
printer.
