JPH02235765A - Dot impact type serial printer - Google Patents

Abstract

PURPOSE:To prevent a print head from burning by calculating ratio of number of dots of printing data of one line to be externally given to maximum number of dots to be printed of one line, discriminating whether it is higher than a predetermined ratio or not, and moving, after printing, only a carrier predetermined times if it is the predetermined value or more. CONSTITUTION:In printing ratio discriminating means 7, whether cooling of a printing head 1 of temperature rise after next one line is printed is required or not according to calculated value of the ratio of the number of dots. That is, if it is a predetermined ratio or more, cooling of the head 1 is required after next one line is printed. Main control means 6 cools the head 1 by this determination by stopping next printing after one line is printed and moving only a carrier 2 predetermined times.

Description

[Detailed Description of the Invention] [Summary] For dot impact type serial printers that require printing pause operations, the present invention aims to efficiently reduce temperature without degrading print quality and prevent print head burnout. A carrier control means for driving a carrier carrying a print head to reciprocate along a platen, a print head control means for controlling the print head, and an analysis of one line of print data given from the outside. A dot-impact type serial printer comprising a main control means for controlling at least the carrier control means and the print head control means and performing printing control based on the print data, the dot impact type serial printer having a print ratio determination means, and a print ratio determination means. The means of determination is
The main control means calculates the ratio of the number of dots of the print data of one line given from the outside to the maximum number of printable dots of one line, and determines whether the ratio is equal to or higher than a certain ratio. The carrier is configured to move only the carrier a predetermined number of times after printing the print data given from the outside when the printing ratio determining means determines that the printing ratio is equal to or higher than a certain ratio.

[Industrial Field of Application] The present invention relates to a dot impact type serial printer, and particularly to a dot impact type serial printer that requires a printing pause operation.

In recent years, dot impact type serial printers are required not only to increase speed and print for a long time, but also to print with higher quality. For this reason, the burden placed on the print head,
That is, temperature rise becomes a problem, and depending on the temperature rise, there is a risk that the print head will burn out, and it is necessary to prevent this burnout.

[Conventional technology] Conventionally, in dot impact type serial printers, the temperature of the print head increases due to continuous printing or high-density printing, and the following measures were taken to prevent the print head from burning out due to the temperature rise. .

As a temperature detection means, a temperature detection sensor is mounted on the print head itself, and a signal is generated when the print head exceeds a certain temperature. Alternatively, as a temperature prediction means, the ratio of the number of dots in one line of print data sent from a host device to the total number of print dots in one line to be printed is determined, and it is determined whether the ratio exceeds a certain value. When the temperature exceeds the above-mentioned constant temperature or constant value, the printed characters are divided in the line feed direction, and one line is printed a plurality of times. For example, as shown in the example in Fig. 4, the head bin is divided into three parts, each of which prints by making one round trip.
By printing one line in three reciprocations, the temperature rise in the print head was suppressed and burnout of the print head was prevented.

Furthermore, the print head carrier has been stopped in response to temperature rise detection to cool the print head.

[Problem to be solved by the invention] However, in the divisional printing in the above conventional technology,
Many parts of the printing operation depend on the positional accuracy of the mechanical parts, and if the accuracy deteriorates for some reason, the divided parts of the printed characters will open or overlap, reducing the print quality. .

Furthermore, in the method of stopping the carrier of the print head, there is no movement, which gives the operator anxiety as if there is a malfunction.

The present invention was created in view of these problems, and
It is an object of the present invention to provide a dot impact type serial printer that can efficiently reduce temperature without deteriorating print quality and prevent burnout of a print head.

[Means for Solving the Problem] The means in the present invention for achieving the above object are as follows:
As shown in the functional block diagram of the present invention shown in FIG. means 5, and a main control means 6 which analyzes one line of print data given from the outside, controls at least the carrier control means 4 and the print head control means 5, and performs printing control based on the print data. The dot impact type serial printer is equipped with a printing ratio determining means 7, and the printing ratio determining means 7 calculates the number of dots of one line of print data given from the outside with respect to the maximum number of printable dots of one line. The main control means 6 calculates the ratio and determines whether it is a certain ratio or more, and when the printing ratio judgment means 7 determines that the printing ratio is more than the certain ratio, the main control means 6 controls the printing ratio given from the outside. A dot impact type serial printer is used which controls the movement of only the carrier 2 a predetermined number of times after printing the print data.

[Operation] In the present invention, the printing ratio determining means 7 determines whether or not cooling is necessary for the temperature rise of the print head 1 after printing the next line, based on the calculated value of the ratio of the number of dots. In other words, if the ratio is above a certain level, the print head 1 needs to be cooled after printing the next line. Based on this determination, the main control stage 6 cools the print head 1 by stopping the next printing after printing one line and moving only the carrier 2 a predetermined number of times.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of a control system of a dot impact type serial printer which is an embodiment of the present invention. 21 is a CPU, 22 is a host interface for connection with a host device (not shown), 23 is a program ROM, 24 is a character generator for generating character fonts, 25
is a RAM, 26 is a line buffer in which I-line print data is stored, 27 is a print head control circuit that fires each head pin of the print head 28 based on the output from the line buffer 26, and 29 is a line feed motor that drives paper feed. 30 is a line feed control circuit that controls the print head 2; 31 is the print head 2;
This is a carrier control circuit that controls a carrier movement motor 32 that moves carriers No. 8.

In the above configuration, the operations of the main control means and printing ratio determining means in the present invention are performed under the control of the flowchart shown in FIG.

In addition, in the address A of the RAM 25 in the above configuration,
Data on the maximum number of printable dots in one line of printing and head temperature proportional data, which is a criterion for determining the temperature rise of the print head 28, are stored at address B.

As shown in the flowchart of FIG. 3, the printing operation in this embodiment is as follows: (1) The CPU 21 receives one line of print data via the host interface 22.

(2) If the received print data is a character code, it is subjected to bit expansion by the character generator 24 and stored in the line buffer 26.

(3) Transfer the maximum number of printable dots (b) stored at address A of the RAM 25 to the CPU 21.

(4) The print data in the line buffer is transferred to the CPU 2l, and the number of dots (a) of the received print data is transferred to the CPU 2l.
). (5) In the CPU 21, the dot ratio (θ=a+b
).

(6) Transfer the head temperature proportional data (α) stored at address B of the RAM 25 to the CPU.

(7). (8) Compare the dot ratio (θ) and head temperature proportional data (α).

(9) If the dot ratio (θ) is equal or small, that is, if the temperature rise of the print head 28 during printing of this L line is within the permissible range, the print head control circuit 27 and carrier control circuit perform normal printing. A drive command is issued to 31, and the ■ line is printed.

(10) When the printing process for one line is completed, the line feed control circuit 29 is controlled to perform a line feed, and the process returns to (1) to receive the next print data.

(11) In the comparison of (8) above, the dot ratio (θ
) is large, that is, when the print head 28 needs to be cooled, a drive command is issued to the print head control circuit 27 and carrier control circuit 31 to print one line.

(12) When the printing process for one line is completed, the line feed control circuit 29 is controlled to perform a line feed.

(13) Stop the operation of the print head control circuit 27,
Issue a drive command only to the carrier control circuit 31, (14)
The carrier is driven three times.

(15) When the three reciprocating drives are completed, the print head 2
At the end of the day's cooling, the process returns to (1) to receive the next print data.

In this way, in this embodiment, the need for cooling in response to temperature rise is determined by the ratio of the number of dots of received print data for one line to the number of dots that can be printed for one line, that is, the number of head pins fired in the print head 28. Determine whether or not. Cooling of the print head 28 is performed by reciprocating the carrier without driving the print head 28 after printing the line (1).

As a result, if the number of times the carrier is moved back and forth in conventional divided printing is 3 round trips, this embodiment can also be moved as fast as before if the number of times it moves including printing and movement of only the carrier is 3 round trips as described above. It is possible to print with . Moreover, since printing is performed once, there is no deterioration in printing quality.

In the above embodiment, it is determined whether or not the print head needs to be cooled before printing the (1) line, but it may be determined after the printing is completed.

[Effects of the Invention] As explained above, according to the present invention, there is no deterioration in printing quality because split printing is not used, and the carrier continues to operate even when printing is stopped, so it does not cause anxiety to the operator. Moreover, the movement of the carrier increases the cooling effect, efficiently lowers the temperature, and prevents burnout of the print head, which greatly contributes to improving the performance of such dot impact type serial printers.

[Brief Description of the Drawings] Fig. 1 is a functional block diagram of the present invention, Fig. 2 is a block diagram of a control system according to an embodiment of the present invention, Fig. 3 is a control flowchart of the embodiment, and Fig. 4 is a conventional control system. FIG. 3 is an explanatory diagram of divided printing. DESCRIPTION OF SYMBOLS 1... Print head, 2... Carrier, 3... Platen, 4... Carrier control means, 5... Print head control means, 6... Main control means, 7... Print ratio Judgment means, 2I...CPU, 22...Host interface, 23...Program ROM, 24...Character generator, 25...RAM, 26...Line buffer, 27...Print head Control circuit, 28...Print head, 29...Line feed control circuit, 31...Carrier control circuit. 4111a block diagram of the present invention FIG. 1 A block diagram of a control system according to an embodiment of the present invention Explanatory diagram of conventional divided printing FIG. 4

Claims (1)

[Claims] Carrier control means (4) for controlling a carrier (2) on which a print head (1) is mounted to reciprocate along a platen (3); and a carrier control means (4) for controlling the print head (1). Print head control means (
5) and analyze one line of print data given from the outside,
A dot impact type serial printer comprising a main control means (6) for controlling at least the carrier control means (4) and the print head control means (5) and performing printing control based on the print data, the dot impact type serial printer comprising: printing ratio determining means; (7), this printing ratio determining means (7) calculates the ratio of the number of dots of the print data of one line given from the outside to the maximum number of printable dots of one line, and calculates the ratio of the number of dots of the print data of one line given from the outside, and the ratio is equal to or higher than a certain ratio. The main control means (6) is for determining whether or not the printing ratio determination means (7)
If the determination is that the ratio is higher than a certain ratio, after printing the print data given from the outside, the carrier (2)
A dot impact type serial printer characterized by controlling the chisel to move a predetermined number of times.