Since the introduction
of the original HP LaserJet printer there has been a demand for additional
typefaces to compliment the printers resident fonts. The early
LaserJet printers prior to the LaserJet III printer in 1990 had a
resolution of 300 dots per inch (dpi) and only supported fixed size
fonts, called PCL bitmap soft fonts. The arrival of the LaserJet
III printer saw the resolution increased to 600 dpi and the addition
of support for scaleable soft fonts. Both formats are
detailed below.
Bitmap Fonts
For PCL
bitmap fonts a separate font must be created for each required
size. Therefore if a typeface was required to be used at 10,
12 and 14 point and was required in regular and italic weights,
six fonts would need to be produced.
In addition a
bitmap font is manufactured at a specific resolution of usually
300 or 600 dpi and a font can only be used on a printer with
equal or greater resolution than the font. Therefore a 600
dpi font can not be used on a 300 dpi printer and although
a 300 dpi font can be used on a 600 dpi printer it will produce
a below standard image.
Scaleable Fonts (Downloable TrueType fonts)
The scaleable
font format differs from a bitmap font because the character
data is stored as a mathematical outline. This enables a single
font to be used for all sizes as the outline data can be scaled
to any required size. The other benefit of using a scaleable
outline is that as it does not have a specific resolution,
the printed image is always produced at the maximum resolution
of the printer.
The scaleable font format is supported by all HP LaserJet printers
from the HP LaserJet III onwards.
A soft font is the
general term given to fonts that can be added to a printer. Depending
on the specific printer and the customers requirements, soft
fonts can be supplied either as downloadable fonts on diskette
or on cartridges, SIMMs or DIMMs which physically
plug in to the printer itself. The options are covered below.
Downloadable fonts
Fonts
that are supplied on diskette are usually referred to as downloadable
fonts as they need to be downloaded to the printer before they
can be used. The process of downloading is very simple if the
printer is connected to a PC, in which case the fonts can be
downloaded using the DOS copy command. Once downloaded the
fonts remain resident in the printer until either the printer
is switched off or a command is sent to the printer to delete
the downloaded fonts.
The major advantage
to downloadable fonts is one of cost as there is no printer
specific hardware involved. The major disadvantage is that
the fonts need downloading each time the printer is switched
off.
Fonts stored in
the printer
Most LaserJet
printers have a mechanism by which soft fonts can be stored
on the printer. The early LaserJet printers had a cartridge
slot into which a font cartridge could be plugged and newer
LaserJet printers support either font SIMMs or font DIMMs
which are added inside the printer. Some high end LaserJet
printers even have a hard disk which can be used for storing
soft fonts.
All of the these
methods of storing fonts on a printer are non-volatile which
means that the fonts are not deleted when the printer is switched
off. The advantage being that the fonts are always available
with no user intervention required.
Once soft fonts
have been added to a LaserJet printer they are accessed by sending
an escape sequence which selects the font ready for use. Data
is then sent to the printer as usual and will be printed using
the selected font.
Although TrueType
fonts are great for Windows and Apple Mac users, HP soft fonts
are often an ideal solution for companies using other operating
systems such as Unix and DOS.
Although this article
refers specifically to Hewlett Packard printers, a large number
of office laser printers emulate HP printers and therefore should
support the use of HP soft fonts. For more information regarding
HP soft fonts, containing typefaces, logos, signatures, symbols
or quality marks, please contact the sales team for more information.
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