JPS5919176A - Heat transfer printer - Google Patents

Abstract

PURPOSE:To provide a heat transfer printer, by a method wherein a part of a paper is heated by a heater means immediately before printing is made for sustaining the heating of the thermal head in order to obtain sufficient printing density and for avoiding unevenness in printing-shade. CONSTITUTION:In a heat transfer printer for transferring the ink of an ink ribbon 3 to a paper 2 by means of heating of a thermal head 4, the thermal head 4 and a thermosensor 5 are arranged to press the ink ribbon 3 and the paper 2 to a platen 1 at a position from which printing is to start, the thermal head 4 is heated in accordance with printing data, printing is conducted while sending the ink ribbon 3 by means of turning an ink ribbon feeding reel 7 and a winding reel 8 and while printing at least a part of the paper 2 which is immediately before to be printed is heated by a heater 6 in accordance with the temperature near the head.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer printer that performs printing by heating a thermal head to transfer ink from an ink ribbon onto paper.

Conventionally, in thermal transfer printers, the amount of ink transferred changes depending on the degree of heating of the ink, and as a result, printed characters may have shading depending on the degree of heating. In addition, when printing by continuously applying heat to the thermal head, the characters may have shading at the beginning and end of printing.1 Also, if the entire paper is heated to a certain extent, If there is a way to improve retention, the characters will still look pale. In addition, if continuous heating is performed, shading will similarly occur. An object of the present invention is to provide a thermal transfer printer that can obtain sufficient print density by suppressing heating of the printer.Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an external view of a heat transfer printer that is an embodiment of the present invention. In the figure, 1 is the platen, 2 is the printing paper,
6 is an ink ribbon that is melted by heating and transferred to printing paper; 4 is a dual head consisting of a plurality of resistance heating elements;
5 is a temperature sensor that detects the temperature around the thermal head, and 6 is a roller type heater that heats the printing paper 2. It has a resistor inside, and by passing a current through the resistor. cause fever. This heater is located in front of the thermal head 4 in the printing direction. ? has been done.

7 is an ink ribbon supply reel, 8 is a winding glue
In addition, the above-mentioned thermal head 4° temperature sensor 5. Heater 6. An ink ribbon supply reel 7 and an ink ribbon take-up reel 8 are mounted on a carriage 9.

FIG. 2 is an external view of a thermal transfer printer in which a plate-type heater 6' is used in place of the roller-type heater 6 shown in FIG. 1.

FIG. 6 shows the roller type heater 6 of FIG. This is a control circuit for controlling the plate-type heater 6' of FIG. 2. In the figure, numerals 4 and 6 are the temperature sensor and heater shown in FIG. 10 determines the most suitable current to be applied to the heater 6 based on the temperature around the thermal head obtained from the temperature sensor 4 with reference to a table 11, and supplies a current to the heater 6 according to the determined current value. Reference numeral 11 denotes a table storing supply current values based on the relationship between the temperature around the head and the heating temperature by the heater, as shown in FIG.

Zu-Full Head 4. The temperature sensor 5 is connected to the device C that starts printing, t, I that pushes the ink ribbon 6 and paper 2 onto the platen 1.
and heats the one-maru head 4 according to the print take,
The ink ribbon supply reel 7 and the ink ribbon take-up reel 8 are rotated in the direction of the arrow to advance the ink ribbon 6 while printing is executed from the left side to the right side. During printing, the lagoon around the head IJL r(- ↓[6] Next, heat the heater 6 to 11 power to heat at least a part of the paper before printing and start printing.This heater 60 system (all
The temperature sensor 4 detects the temperature around the thermal head 50 in 4.T.
ζ Send the crystallinity value to 〃11 Heater control fits IU t1
Do 1.

The heater control unit 10 refers to the table 11 based on the temperature value sent from the temperature sensor 4 and determines the optimal 1υ, 61Th fio to be supplied to the heater 6. Then, supply the optimum current to the heater 6, r knee, 7 Jl.
+ Heat.

As shown above, the current supplied to the heater 6 determined by the heater control unit 10 is determined by the current supplied to the heater 6 from the drawing showing the relationship between the head surrounding temperature and the heating temperature by the heater 6 in FIG.
This is done by referring to the table 11 which stores the optimum current value to be supplied to.

As explained above, according to the present invention, by heating at least a portion of the paper just before printing and by changing the heating depending on the temperature around the thermal head, it is possible to eliminate the disadvantage of printing shading, and to It is possible to obtain sufficient printing quality without increasing the heating too much, and since the heater is located in front of the thermal head in the printing direction, dirt does not adhere to the heater when the ink is fixed. Therefore, it is possible to provide a thermal transfer printer that does not require any measures against contamination of the heater with ink.

[Brief explanation of drawings]

FIG. 1 is an external view of a thermal transfer printer according to an embodiment of the present invention.
Fig. 2 is an external view of a thermal transfer printer according to another embodiment, Fig. 6 is a block diagram of a control circuit that performs tf control of the heater, and Fig. 4 is a diagram showing the relationship between the heating temperature of the heater and the temperature around the head. It is a figure showing a relationship. 6...Φ・Ink ribbon 4...γ^A degree sensor 5111+11...Thermal head 6・轡・Se-7JII M B Applicant Ki\'Non Co., Ltd. Agent 9 Noi% Gi - 1゛: aH+, ^-

Claims (1)

[Scope of Claims] A thermal transfer printer that performs printing by transferring ink from an ink ribbon onto paper by heating a thermal head, characterized in that a heating means is provided for heating at least a portion of the paper immediately before printing. Thermal transfer printer.