JPS61108574A - Thermal printer - Google Patents

Abstract

PURPOSE:To increase the printing speed of a thermal head, by preheating an ink ribbon in a printing pattern form by one heat generating part and performing printing by the remaining heat generating part. CONSTITUTION:Heat generating parts TH1, TH2 respectively having, for example, 24 dot lines have common electrodes CT1, CT2 and dot electrodes DT and driven by the signal respectively applied thereto. When a printing order P and printing information PI are sent from an information processing apparatus, a carriage CAR is set to a home position at first and subsequently begins to move from the home position to the rightward direction. A thermal head H is contacted with recording paper under pressure through an ink ribbon and the ink ribbon is at first preheated by the heat generating part TH1 to be heated in a pattern form and moved along with the carriage to allow the preheated part to reach the position of the heat generating part TH2 where the ink ribbon is further heated in a printing pattern form by the heat generating part TH2 while the molten ink on the recording paper is transferred at every one column to perform printing.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a thermal printer capable of high-speed printing.

[Prior Art] Conventional thermal printers have been limited in the number of prints per unit time to prevent overheating of the thermal head.

[Objective] An object of the present invention is to provide a thermal printer that can improve the above-mentioned drawbacks.

Another object of the present invention is to provide a thermal printer that can realize high-speed printing by providing a thermal head with a plurality of columns (or rows) of heat-generating sections and supplying the same signal to the plurality of columns of heat-generating sections.

Other objects of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[Example] Figure 1 is a top view of a printer for explaining the present invention in detail. In the figure, l is a platen roller.

2 is a platen roller (recording paper that is wound). 3 is a carriage, which moves in the direction of the arrow when printing. 4 is a thermal head.

In Figure 1, the circuit is placed on the carriage 3 and a circuit is formed on the thermal head as shown in Figure 2.
, TH2 are emitting fIS parts of, for example, 24 dot rows, and have common electrodes CTI, CT2, and dot electrodes 5iDT,
Driven by signals applied to each. SR is a serial-parallel-out shift register, and R is a parallel-in-parallel-out register. G1. G2
and G3 are transfer gates.

Returning to M 1 lΔ, 5 is an ink ribbon supply reel, and 6 is an ink ribbon take-up reel. The supply reel 5 and the take-up reel 6 are provided within a cassette, for example.

FIG. 3 is a block diagram of printing control. In the same figure,
H is a thermal head, which corresponds to the thermal head 4 in FIG. CAR is a carriage, carriage 3 in Figure 1.
corresponds to A belt B is fixed to the carriage CAR and moves the carriage CAR in the axial direction of the platen l. RL1 is an idle roller provided near one end of the platen roller 1, and around which a bell) B is wound.

RL2 is a roller around which the belt B is wound, and the belt B is moved by the roller. RL3 is a roller, roller RL
It is fixed coaxially with 2.

TG is an encoder, which is fixed coaxially with the rollers RI and 2, and generates a signal in accordance with the rotation of the shaft A. 0M is a motor, which rotates the roller RL3 via the drive roller DH. C0NTl is a control circuit that starts the motors M and RM based on the pre-7 command 9 from the information processing device, picks up the encoder TG signal, and controls the motor M.
feedback control, and also generates printing timing signals.

C0NT2 is a control circuit that receives print information (for example, dot patterned information 24×24, 24 dots at a time) from the information processing device and sends it to the thermal head H.

FIG. 4 is a block diagram showing details of the control circuit C0NT2. OSC is a signal generator, and FF in FIG. 5 is a flip-flop, which generates a signal like FFS in FIG. 4 using a signal obtained through an AND gate AG.

051 is a one-seat signal, and outputs an 85r14tyyO5IS Noyora lx signal te with the output of a flip-flop FF.

032 is a one-shot, activated by a print command, and the fifth
A signal like 0525 in the figure is output.

RM is a motor that drives the take-up reel 6, and drives the take-up reel 6 via a frictional engagement member in order to feed the ink ribbon in a fixed amount.

The operation of the embodiment configured as described above will be explained.

When a print command P and print information PI are sent from the information processing device, the carriage is first set at the home position, and then the carriage CAR starts moving from the home position (left end) to the right. The thermal head H is brought into pressure contact with the recording paper through the ink ribbon. First, the ink ribbon is preheated by the heat generating part THI, and the ink ribbon is heated in a pattern. The carriage and the ink ribbon move, and the preheated area is heated. When the ink ribbon reaches the 1% portion TH2, the ink ribbon is further heated in a printing pattern by the heating section TH2, and the melted ink is transferred column by column as shown by arrow B in FIG.
The carriage feed and the ink ribbon feed amount are controlled so that printing is performed (indicated by dots in column 7 in the figure) and the carriage and ink ribbon do not slide.

The above control will be briefly explained. First, control W circuit C0
A print command P is applied to NTl, and a signal for driving the seventh motor M and the motor RM is output, and the motor M rotates at a constant speed Mlj based on the signal from the encoder TG. On the other hand, print information is applied to the control circuit C0NT2, which converts the signals sent in parallel into serial signals and sends them to the thermal head H.

The 24-dot print information sent serially is stored in the serial parallel output shift register SR.
Next, it is applied to the heat generating part THI via the transfer gate G2,
The heat generating part THI generates heat due to coincidence with the selection signal sent to the common electrode CTI.A transfer signal arrives at the 0th order, new 24-dot print information is applied to the shift register SR, and the contents of the shift register SR are changed. It is transferred to register R via transfer gate G3.

Next, when a drive signal comes, the ink ribbon is heated again by the heat generating part TH2 and printing is performed.6 Heat generating part TH2
The location where the ink ribbon is heated is the location heated by the heat generating portion THI.

As described above, by pre-printing the ink ribbon in a printing pattern with one heat generating part and printing with the remaining heat generating part, heating of the heat generating part can be prevented and the printing speed of the thermal head can be increased.

[Brief explanation of the drawing]

FIG. 1 is a top view illustrating an embodiment of the present invention, and FIG. 2 is a diagram illustrating a thermal head. FIG. 3 is a diagram explaining control, FIG. 4 is a detailed diagram of the control circuit C0NT2, FIG. 5 is a waveform diagram, and FIG. 6 is a diagram explaining a printing example. S R-----Shift register G 3-----One transfer gate

Claims (1)

[Claims] A thermal printer comprising a plurality of columns (or rows) of heat generating sections and means for sequentially applying the same information to the plurality of columns of heat generating sections.