JPS60242070A - Printing system of multiple head type dot printer - Google Patents

Abstract

PURPOSE:To continue printing even though high printing duty connects, by a method wherein the printing head to be applied to printing is selected from plural printing heads in accordance with the temperature of each printing head, and shifted to a printing paper. CONSTITUTION:The temperature of each printing head is detected with a temperature sensing part 11 and all or any one of head drivers 14-1-14-4 corresponding to a specific printing head are selected. Then, a printing data is given to the selected driver via a printing mechanism control part 15 by driving an SP motor 12 and printing is carried out by movement of a head carriage 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a printing method for a multi-head dot printer, and more particularly to a printing method when the head generates heat.

(Background Art) Conventionally, in a multi-head focus printer (hereinafter referred to as LP), when printing continues with a high print duty load, the print head used in the LP generates heat. If the heat generation temperature becomes high, the excitation coil for driving the printing element used in the print head may burn out, so set a certain temperature T1℃ and reduce the printing speed to reduce the actual printing duty. It's on. If the print head continues to generate heat even if the printing speed is reduced, a limit temperature of T2°C is set (T2>TI), and when the temperature reaches 12°C, printing is stopped and the print head is cooled down. Wait until the head temperature drops to below 12°C, then start printing again. However, when reducing the printing nupid, there is a delay time from the printing command pulse to printing, as shown in Figures 5(a) and 5(a), and this time is approximately 370 μs in the case of the conventional device. is constant regardless of printing speed. As shown in Fig. 5(a), when the printing command pulse interval in the normal case is 740 μs,
Because the printing delay time is %, printing is performed at almost the same position whether the printing direction is forward or requisite, as shown in (b) of Figure 5 (C) at normal printing speed. (In (o) of FIG. 5(C), the upper side shows the forward direction printing, and the lower side shows the reverse direction printing. Note that (a) of FIG. 5(C) shows the printing position. )
. On the other hand, when the printing speed decreases as shown in Figure 5), the ratio of the printing command pulse to the printing delay time gradually decreases in proportion to the decrease in printing speed, so the apparent The printing delay decreases, and as in the case of the printing speed decrease shown in (c) of Fig. 5(C), a difference δ between actual printing occurs between forward direction and reverse direction printing, and the difference δ is There was a drawback that the printing speed increased in proportion to the decrease in printing speed (in (c) of FIG. 5(C), the upper side is when printing in the forward direction, and the lower side is when printing in the reverse direction).

In addition, the second drawback is that when considering printing quality and printing under conditions where the difference δ does not change significantly compared to normal printing, the limit to which the printing speed can decrease is about 80% of the normal printing speed. However, this method also had the disadvantage that the temperature of the print head could not be lowered to that extent and reached a temperature at which printing should be stopped.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned drawbacks of the conventional technology, and even if the print head temperature rises due to continuous high printing duty,
To provide a printing method for a multi-head dot printer that can continue printing while maintaining print quality.

(Summary of the Invention) The key points of this invention to achieve this object are: a plurality of print heads composed of a plurality of print elements; a carriage on which these print heads are mounted at regular intervals; In a dot line printer that prints one line with the plurality of print heads, it has a space motor that moves left and right with respect to the print paper, and a line field motor that moves the print paper and performs a line feed. means for detecting temperature; and means for selecting a print head to be used for printing from among the plurality of print heads based on the temperature of each print head, and controlling the space motor and the line motor; The printing may be performed by moving the selected print head with respect to the printing paper once or multiple times.

Hereinafter, the present invention will be explained based on embodiments with reference to the drawings.

(Example) FIG. 3 is a plan view of the printing mechanism section of an LP having four print heads as an example, and FIG. indicates the end of printing. 1 is a platen, and 2 is a space motor (hereinafter referred to as an SP motor).

The carriage moves left and right by an SP motor (not shown), 3-1.3-2.3-3.3-4 are print heads fixed to the carriage 2 at regular intervals, and 4 is printing paper. , A.I.

A2, A3, and A4 are print heads 3-1, respectively.
．． The printing range of 3-2.3-3.3-4 is shown. here,
If the number of characters printed for one line is 88 characters, there are 4 print heads (3-1, 3-2, 3-3, 3-4,), so
Each head prints 22 characters in one printing operation.

FIG. 1 is a block diagram of an LP showing an embodiment of the present invention. 11 is the print head 3-1.3-2゜3-3.3-
Temperature sensing part that senses the temperature of 4.

12 is an SP motor that moves the carriage 2 in FIG. 3 left and right; 13 is an LF motor that feeds the printing paper 4 in FIG. 3;
14-1.14-2.14-3 and 14-4 are head drivers for driving printing elements constituting the corresponding print heads 3-1.3-2.3-3.3-4, and 15 is an sp Motor 12, LF motor 13, and head driver 14-1.1
4-2.14-3.14-4 and the like.

FIGS. 2(a) to 2(C) are operation timing diagrams of the LP shown in FIG. 1.

An example of the printing operation will be described below with reference to FIGS. 1 and 2. Each print head 3-1.3-2.3-3.3
-4 is detected by the temperature sensing section 11, and a predetermined print head 3-1.3 is detected according to the detection level.
-Bed driver 14- corresponding to 2.3-3.3-4
1, 14-2, 14-3, or any one of 14-4 is selected, and then the KSP motor 12 is driven, and print data is transmitted from the control device (not shown) to the print mechanism control unit 5 via the selected item. One line is printed by moving the hemlock carriage 2 in the left or right direction once or by moving it several times (for example, by moving it forward and backward twice). For example, if the temperature detection level of all the print heads is 11 degrees Celsius or less, all the print heads 3 are detected at once by moving the carriage 2 forward and reverse in Fig. 3, as shown in Fig. 2 (a).
Select the head driver 14-1.14-2°14-3.14-4 corresponding to -1.3-2.3-3°3-4.
Prints a line. Therefore, in this case, one line is printed during the forward run and one line is printed during the next reverse run. In each of Figures 2 (a) to (C), when a pulse exists (on), the component corresponding to the pulse is in the on state, and when no pulse exists (off), the component corresponding to the pulse is in the on state. state. Next, if the temperature detection level of one print head is higher than T1℃ and lower than T2℃,
), the head driver 14-1.14-2 corresponding to the print head 3-1.3-2 is selected in forward running, printing is performed, and a line feed (LF) is performed, and then the print head is moved in reverse running. Head driver 14-3.14-4 corresponding to 3-3.3-4 is selected and printing is performed to print one line. Therefore, in this case, the printing speed is increased by running twice, forward running and reverse running, as shown in Figure 2 (
In the same way as in case a), one line is printed and a new line is inserted. Next, when the printing duty is high and the head temperature rises even when printing is performed in two times, and one of the four heads reaches the limit temperature of 12°C, the temperature detection level becomes 12°C or higher. In this case, as an example, the second print head 3-
FIG. 4 shows the case where 2 reaches the critical temperature. In this case, the print head 3-2 is unable to print, so instead, the print head 3-1 prints an additional 22 characters, which is the print range of the print head 3-2. Therefore, print head 3
-1 means that a total of 44 characters will be printed. Figure 2 (C
) is an example of this, in which print head 3 is first used in the first half of forward printing.
The head driver +4-1 corresponding to -1 is selected to perform printing, and the print head 3-1 continues to space until the print head 3-2 reaches the reverse print start position. Thereafter, the head driver 14-1 corresponding to the print head 3-1 is selected during the first half of reverse travel without performing a line feed, and printing is performed in the range that the print head 3-2 should be responsible for.

Thereafter, the head driver 14-3.14-4 corresponding to the print head 3-3.3-4 is selected to perform printing. Therefore, in this case, one line is printed by forward running twice the normal distance and reverse running twice the normal distance, and then a line feed is performed.

As explained above, according to this embodiment, the printing speed is changed to the normal printing speed A when the temperature detection level T1°C is 72°C, and is still at the temperature detection level T2°C. In the case of , since the running speed of the carriage can be changed while keeping the normal printing processing speed constant, there is no deterioration in printing quality. In addition, the effective printing processing speed is 50% (%) and 25% (I) compared to the conventional 80%.
The situation where the LP stops due to an alarm due to temperature rise is only in extremely limited cases where high printing duty continues, and normally this does not occur, and the LP
P is stopped and the so-called "dumb" state no longer occurs.

(Effects of the Invention) As explained above, according to the present invention, a multi-head dot printer that can continue printing while maintaining print quality even if the print head temperature rises due to continuous high printing duty. method can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
) to (C) are operation timing diagrams of the device shown in FIG. (b) is a plan view of the printing operation of an embodiment of the present invention, and FIGS.
(C) is a diagram showing the state of printing when the printing speed is constant and when the printing speed is decreased. 1. Platen, 2. Carriage, 3-1. ,3-2
．． 3-3.3-4... Print head 1.4... Print paper, 11... Temperature sensing section, 12... SP motor,
13・LF motor, 14-1.14-2.14-3.1
4-4 head driver, 15... printing mechanism control section,
A1-A4...Print head printing range. Patent Applicant: Oki Electric Industry Co., Ltd. Patent Application Agent Megumi Yamamoto - 1st Diagram System # 2nd Diagram (a) 2nd (b) (8) To, i″11 Rhino 14-2 (D) Bed driver 1 key 3 (E) λ Sodo Y Live 14-4 (F) LP low power Figure 2 (C) (F) LF low power Figure 3 (Q) Figure 5 (Q) ) Figure 5 (b) Figure 5 (C)

Claims (2)

[Claims] (1) A plurality of print heads consisting of a plurality of print elements, a carriage on which these are mounted at regular intervals, a space motor that moves the carriage from side to side with respect to the print paper when printing, and a print paper. The dot line printer has a line field motor that prints one line using the plurality of print heads, and includes means for detecting the temperature of each print head, and means for detecting the temperature of each print head based on the temperature of each print head. means for selecting a print head to be used for printing from among a plurality of print heads and controlling the space motor and the line motor; A printing method for a multi-head dot printer characterized in that printing is performed by moving the dot once or multiple times. (2) When all of the print heads are below the predetermined temperature TI°C, all the print heads are selected and one line is printed by one movement of these print heads, and one of the print heads is at a temperature above 11°C. When the temperature drops below 72°C, the print head used for printing when the carriage moves to the right and the print head used for printing when it moves to the left are selected, and by moving in both directions, one line is printed. is printed, and when one of the print heads reaches a temperature of 12°C or higher, multiple print heads including the print head adjacent to the print head are selected for rightward and leftward movement of the carriage, respectively, and the print heads are selected for both of these directions. 2. The multi-head dot printer according to claim 1, wherein one line is printed by moving the dot printer.