Thermal recording apparatus
AssigneeBrother Kogyo Kabushiki Kaisha
InventorKatsuhito Kurachi
Life of this patent
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Abstract
The number of pulses N corresponding to the gradation level of a print dot is read out from a table and stored in a counter 63 (S1). The first pulse is applied to the heating elements for the duration T.sub.1 (S4) and is stopped for the duration T.sub.off (S6). The number of pulses N is read out and restored in the counter after the subtraction of 1 therefrom (S7). The second pulse is applied for the duration T.sub.2 (S9) and then interrupted for the duration T.sub.off (S11). The number of pulses N is read out and, after 1 subtracted therefrom, is restored (S12). If the number of pulses N read out is not zero, the step for the application of pulses for the duration T.sub.2 (S9) and subsequent steps are repeated. If the number of pulses N is zero, the application of pulses is terminated (S13).
Claims7
A thermal recording apparatus, including:
- a thermal recording device provided with a plurality of heating elements, the thermal recording device capable of printing a pixel with a number of gradation levels "n";
- pulse application means for selectively applying a drive pulse train to the heating elements, the pulse application means capable of applying a number of drive pulses "m" that is larger than the number of gradation levels "n" to the heating elements;
- pulse number setting means for setting a number of pulses of the drive pulse train according to gradation density of the pixel to be printed through the heating elements;
- pulse width setting means for setting a width of a first drive pulse of the drive pulse train to be larger than those of a second and subsequent drive pulses;
- and
- pulse control means for applying the first drive pulse to the heating elements thereby to preheat the same up to a predetermined heating temperature and then the second and subsequent drive pulses to the preheated heating elements to record the pixel.
A thermal recording apparatus, including:
- a thermal recording device provided with a plurality of heating elements, the thermal recording device capable of printing a pixel with a number of gradation levels "n";
- pulse application means for selectively applying a drive pulse train to the heating element, the pulse application means capable of applying a number of drive pulses "m" that is larger than the number of gradation levels "n" to the heating elements;
- and
- pulse number setting means for setting the number of drive pulses so as to be larger as the gradation density of a pixel to be printed through the heating elements becomes higher, and setting an increasing rate of the number of pulses so as to be low in a low gradation density area and high in a high gradation density area.
A thermal recording apparatus, including:
- an input device for inputting character data such as characters;
- a thermal head provided with a plurality of heating elements to print the characters input by the input device on a long-sized tape, the thermal recording device capable of printing a pixel with a number of gradation levels "n";
- pulse application means for selectively applying a drive pulse train to the heating elements, the pulse application means capable of applying a number of drive pulses "m" that is larger than the number of gradation levels "n" to the heating elements;
- pulse number setting means for setting a number of pulses of the drive pulse train according to gradation density of a pixel to be printed with the heating elements;
- pulse width setting means for setting a width of a first drive pulse of the drive pulse train to be longer than those of a second and subsequent drive pulses;
- and
- pulse control means for applying the first drive pulse to the heating elements thereby to preheat the same up to a predetermined preheating temperature and then the second and subsequent drive pulses to the heating elements to record the pixel.
Dependencies are inferred from the claim text.