Font Substitution Logic for Recording Devices

The patent extracts only the essential font characteristics (column count, line feed pitch, recording medium characteristics) from the complete font data, storing only these extracted features in the recording device. When a font is specified, the system retrieves the characteristics and finds a matching internal font based on these extracted features, rather than storing complete font files. This resolves the contradiction by storing minimal necessary information to achieve font compatibility.

The patent changes the approach from storing complete font data to storing font characteristics parameters (column count, line feed pitch, recording medium characteristics). By transforming the font representation from full graphical data to parametric characteristics, the system can store font information within limited storage capacity while still enabling accurate font substitution and maintaining print quality.

The patent makes the recording device universal by implementing font substitution functionality that works with any specified font regardless of whether it is stored internally. The device can receive print data with any font specification from the host, retrieve the font characteristics, substitute with an appropriate internal font, and produce comparable output. This multi-functionality allows the device to work with any host device and any specified font, resolving the font availability problem when devices are replaced.

The patent introduces font substitution information as an intermediary between the specified font and the internal fonts. Instead of requiring the specified font to be directly available in the device, the substitution information acts as a mediator that maps the specified font characteristics to matching internal fonts. This intermediary mechanism ensures font availability even when the original specified font is not stored in the device.

The patent implements self-service by enabling the recording device to automatically perform font substitution without requiring changes to the host device's operating settings or application programs. The device independently retrieves font characteristics from the print data, finds matching internal fonts, and performs substitution automatically. This eliminates the need for users to modify host settings, maintaining ease of operation while ensuring printing capability.

The patent performs preliminary action by pre-storing font characteristics and substitution information in the recording device before printing operations begin. The device prepares the font substitution mapping in advance, so when print data arrives with any font specification, the substitution can occur immediately without requiring real-time font installation or host setting changes. This preliminary preparation ensures both productivity and ease of operation.