JPS5867477A - Control on thermal head in heat-sensitive recorder - Google Patents

Abstract

PURPOSE:To permit the performance of high-speed, uniform-dense recording by controlling a power to be applied to each heating element constituting a thermal head according to the past and next printing information for the heating element and the printing information for the other heating element. CONSTITUTION:In a heating element H1, printing information for thermally driving the element H1 is controlled according to signals from RE11 on the one hand and applied, on the other hand, to a register RE01 first, which move to left- handed registers RE11, RE21, ... every recording period. Thus, printing information being recording at present is stored in RE11, the next information is in RE01, and the last before-last, and before before-last printing information is each stored in RE21, RE31 and RE41. Signals from RE01-RE41 and RE12 and the present printing information of the heating element H2 adjacent to the direction at a right angle to the moving direction of the head are each put in a control circuit CC1 to control the pulse width of pulse width signal output from a drive circuit PW1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling a heat generating head in a thermal recording device such as a thermal printer or a thermal transfer link. More specifically, the present invention relates to a method of controlling a heating head having, for example, 24×24 or 1×24 dot heating elements for recording characters or the like in a dot matrix.

The recording density in thermal recording is generally determined by the thermal energy applied from the heat-generating element to the color forming agent or transfer agent.If this is thermally driven in a high heat storage state, the recording will be dark, and in a low heat storage state, the recording density will be dark. When thermally driven, the recording becomes thinner. Therefore, in the past, the heat storage effect was eliminated by incorporating an OR time constant circuit that matched the thermal time constant of the heat generating element into the drive circuit, or the next heat generation was performed by waiting for the heat generating element to drop to a predetermined temperature. A method of driving was used. However, the former method requires a complicated circuit configuration, and the latter method has the disadvantage that high-speed recording cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of controlling a heat-generating head that can perform high-speed recording with uniform density using a simple configuration.

A heat generating head control method according to the present invention applies power to a heat generating head based on the previous print information and the next print information of the heat generating head, and the neighboring information arranged perpendicularly (up and down) to the moving direction of the heat generating head. The invention is characterized in that it is controlled according to the print information of the heat generating head.

FIG. 1 is a block diagram showing an example of a device for implementing the control method of the present invention. Here, we assume a circuit consisting of I x n heat-generating elements, and T represents only the circuit that controls two heat-generating elements arranged in the vertical direction. A similar circuit is used for the heating element. In the figure, Hl and H2 are heat generating elements that constitute a heat generating head, and both of these are composed of a heat generating resistor B and a switching transistor Tr connected in series with it, one end of which is grounded, and the other end of which is connected to a power source. Connected to VOC. PWj and PW2 are drive circuits for one heating element H, , H2, and registers REj+ to be described later.
input the signal from the switching transistor T
Outputs a pulse width signal that turns on and off.

REO1 to RB4+ and REO2 to RE42 are all registers, and here we will start with register ag.
The print information given to the heating element H1 (H2) is applied to o+ (RBO2) and is stored, and this print information is sent to the register Rg11 (RE+ 2) at each recording cycle.
Rgz+(uE22)→RLs+(REs2)→RE4
1 (FLE42). CC+
, CC2 are each drive circuit PW1. This is a PW20 control circuit. This control circuit CC1 (CC2) receives signals from the respective registers REO+ to RJ41 (REO2 to RE42) and the heat generating element H2 (which is adjacent to the heat generating element H1).
The register RE12 (
The pulse width of the pulse width signal output from the drive circuit pw+(pw2) is controlled according to the states of these signals. In addition, here,
These control circuits 001. CC2 and drive circuit PW1
．． Although PW2 is shown as separate blocks, they may also be comprised of a single microprocessor.

The operation of the apparatus constructed in this manner will now be described with reference to FIGS. 2 and 3. Now, focusing on the heat generating element H1, the print information for thermally driving it corresponds to the signal from the register RE11. On the other hand, the print information is first applied to the register REO+, and this is applied to the left register RE11. Move to RE21... Therefore, the currently recorded print information is the content stored in register Rg+1, and the next print information is stored in register Rg01 and register RE21. RE! 51. RB41K stores the print information of the previous time, the previous previous time, and the previous previous previous time, respectively.

The control circuit CC1 receives signals from each register FLEO+ to RE41 and RB12, that is, next printing information.

The previous print information, the previous previous print information, the previous previous print information (these previous print information are collectively referred to as past print information), and the current information of the heat generating element H2 adjacent in the direction perpendicular to the moving direction of F and C. The print information is inputted, and the pulse width of the pulse width signal output from the drive circuit PW1 is controlled according to the print information.

Fig. 2 shows the dots of printing information inputted by the control circuit CC1 when paying attention to the dots (r)jl currently being printed by the heat generating element H1. Print information of D21 to D41 and D12 is input.

The control circuit cc1 inputs each of these print information, and controls the pulse width from the drive circuit PWI, for example, as shown in Table 1, according to the states of these signals. .

Table 1 Figure 3 shows the waveform of the pulse width signal output from the drive circuit PW1. In the case of printing dots, the pulse width is different from the next printing information, past printing information, and the lower side. The distance varies between 1.2 m8 and 2.1 m8 depending on the state of the printed information of the dots adjacent to the dot.

In addition, here, if any of the print information of the previous time, the previous previous time, and the previous previous previous time is 1m, the past print information is collectively set to 11", but this is summarized. Instead, the pulse width may be finely changed according to each pulse width.
1 is designed to input the current printing information of the dot adjacent to the lower side. For example, in the control circuit 002, the signal from the register FLE11 and the signal from the register TLF, 1s, ie, Dora adjacent to the upper side) r) 11 and Dora adjacent to the lower side) D13
It is also possible to input each print information (see FIG. 2) and change the pulse width according to these conditions.

Conventionally, as shown in Japanese Patent Application Laid-open No. 55-150!588, there is a known device that controls the power applied to the head only in accordance with past printing information. However, if only past printing information is used, for example, when recording horizontal lines or vertical lines, it may become blurred or smeared, making it impossible to obtain uniform recording density. There wasn't.

In the present invention, in addition to the past printing information, the next printing information and the printing information of the upper or lower dots or vertically adjacent dots lined up in the direction perpendicular to the dot movement direction are taken into consideration, and the heating element is It is a 5K that controls the power given, and has various shapes such as horizontal lines and vertical lines.

This also has the effect of being able to record characters with uniform density at high speed.

In the above embodiment, the power applied to the heat generating element was controlled by changing the pulse width, which made it possible to configure the entire device with a digital circuit, but by changing the applied voltage, The power may also be controlled. Furthermore, although one heat generating head is assumed to be a case in which heat generating elements are arranged in a line, it is also applicable to a heat generating head in which heat generating elements are arranged in a matrix.

As explained above, according to the control method of the present invention, it is possible to arrange various character shapes (with uniform density) at high speed.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram showing an example of a device for realizing the method of the present invention, FIG. 2 is an explanatory diagram for explaining the state of printed dots, and the $S diagram is an output signal waveform diagram from the drive circuit. It is. RFjol ~RE41. RFi02~RB42-・
Register, H1+) I2... Heat generating element, PWt
, PW2...drive circuit, ccl, cc2...control circuit pH diagram

Claims (2)

[Claims] (1) A method for controlling a heat-generating head in a heat-sensitive recording device having a heat-generating head configured by arranging a plurality of heat-generating elements, the method comprising: controlling the power given to each heat-generating element constituting the heat-generating head; Past printing information and
A method for controlling a heat-generating head in a thermal recording device, characterized in that the control is performed according to the next print information and the print information of other heat-generating elements arranged adjacently in a direction perpendicular to the moving direction of the heat-generating element. . (2) The power given to the heating element is controlled by changing the power pulse width.
A method for controlling a heat generating head in a thermal recording device as described in 1.