JPS6021265A - Dot printer - Google Patents

Abstract

PURPOSE:To prevent the lowering in printing quality, by providing an apparatus for storing the boundary of one block of a printing data, an apparatus for counting the length of the printed data in the block and a means for detecting printing reaching the boundary of one block. CONSTITUTION:Printing data LD1 generated from a printing data source 1 is sent to an image buffer 2 for storing said data and simultaneously sent to a block length memory 4 for storing the data bite number of one block through a decoder 3 for detecting ESC%N to store the data bite number. In the next step, printing data LD2 is similarily sent to the image buffer 2 and the block length memory 4 to a store the data bite number thereof. When the reception of data LD1-LDn corresponding to one line is finished by this mechanism, printing is started. When the voltage of a printing head driving power source is dropped below reference voltage V0, this voltage drop is detected by a voltage drop detecting circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a dot printer such as an impact type or a thermal type that prints characters, symbols, etc. by a combination of a plurality of dots applied by a print head.

[Prior art]

In impact type or thermal type dot printers, there are many dots to be printed at the same time, and in extreme cases, all dots may be printed at the same time. Therefore, the capacity of the print head drive power supply should be adjusted in consideration of printing all dots. However, there is a problem in that it is difficult to increase the driving power supply in order to miniaturize the printer.

Therefore, conventional dot printers detect the voltage drop in the drive power supply, and when the voltage drops below a certain level, they immediately stop printing, and then continue printing the print data after the voltage is restored. In particular, when printing high-density data (so-called image data), there is a drawback that a drop in printing quality is inevitable, such as gaps occurring at interrupted locations due to machine play, motor startup characteristics, etc.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and its purpose is to realize a dot printer that can print without deteriorating print quality with a limited drive power supply capacity. It is something.

[Structure of the invention]

In order to achieve the above-mentioned object, the present invention regularly uses 1
Focusing on the fact that the size of a block can be defined, we developed a means for storing the delimiter of one block of printed data, a means for counting the length of printed data within a block, and a method for calculating one block from the counting result. By providing a means for detecting that printing has been completed up to the end of the line, the length of one pronk of the data to be printed is memorized in advance, instead of immediately stopping printing upon detection of a voltage drop in the drive power supply. Then, at the timing of this block separation, a voltage drop in the power supply is detected and printing is stopped, and after the voltage is restored, printing is performed again from the print stop position, thereby connecting with the previous data. An embodiment of the dot printer according to the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the print data transfer format adopted in the present invention and its printing results. In the case of data with high print density, that is, image data,
Number of data nodes in the block N (in this figure, m
n / 8), and then 1 block N
A format is adopted in which bytes of image data are transferred, and in this example, ESC%N defines the number of data bytes to be sent next.In addition, t1 in the figure is the first of the data to be printed. The block length, t2, is the second block length.

FIG. 2 is a circuit block diagram showing the main part of this embodiment. In the figure, print data LDI in the format shown in FIG. 1 generated from print data source 1 is stored in image buffer 2 for storing this data. The data is sent via a decoder 3 that detects the simultaneous ESC %N to a block length memory 4 that stores the number of data bytes of one block.

Next, print data LD2 is sent to image buffer 2 and block length memory 4 in the same way, and the number of data bytes is stored. In this way, when the reception of data LD1 to LDn for 1 life is completed, printing starts. .

Therefore, if the printing density of certain data among the print data LD1 to LDn mentioned above is high and the voltage of the drive power source of the print head drops below the reference voltage Vo required to not affect the print quality, this voltage drop is detected by the voltage drop detection circuit 5.

Then, the print data length memory 6, which stores the number of data bytes that have been printed in the block, and the matching circuit 7, which detects that the data stored in the block length memory 4 match, are used to separate blocks 9. When the force is detected, the voltage drop control circuit 8 senses the output of the voltage drop detection circuit 5, and controls the print head movement circuit 9 and the print head drive circuit 1.
By controlling 0, printing by a print head (not shown) is temporarily stopped. Thereafter, when the output of the voltage drop detection circuit 5 stops, printing starts again from the printing stop position.

The print data length memory 6 uses a count as an example, and when the first byte data of the front is transferred to the print head drive circuit 1o, the count value "r" is loaded, and then the print head drive circuit 1 ( IIc The count may be incremented every time 1 byte of data is transferred.

Figure 3 shows the block division 9 position of the print data when printing is performed by the FC circuit mentioned above, △ in printing is at the end of m character of l block, (b) is the waveform of voltage drop detection, (C ) shows the waveform during printing, and (d) shows the waveform of the movement of the print head.

As seen in this figure, when a print stop instruction is issued at a block break 9, the print head is decelerated by the print head movement circuit 9 and then stopped. When starting printing again, it returns to the top position of the block before printing was stopped, and from there it accelerates to print the following block.

By printing one line of data in this way, it is possible to print without having to stop printing in the middle of printing image data, which eliminates gaps in connections with the previous data and guarantees print quality. can do.

It should be noted that the present invention is not limited to the embodiments described above, and various design changes are possible. For example, when a printing font such as kanji is included, the delimitation of blocks may be changed depending on the configuration of the font. Since the block length can be uniquely and automatically defined, the present invention can be applied without setting data such as ESC%N.

〔Effect of the invention〕

As explained above, the present invention includes means for storing the delimitation of one block of data to be printed by the print head, means for counting the length of printed data within the block,
1 step from the count result. It is printed up to the tsuku delimiter.
When printing high-density data, a voltage drop is detected at the timing of one block of data, printing is temporarily stopped, and after the voltage is restored. Since printing is started again from the printing stop position, it is not affected by mechanical play or motor start-up characteristics, and high-quality printing can be performed with a limited drive power supply capacity. It has the effect of being able to print, and can be widely used not only in serial dot printers but also in line dot printers, fax machines, and the like.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a print data transfer format adopted in a dot printer according to the present invention and its printing result. FIG. 2 is a circuit block diagram showing a main part of an embodiment of the dot printer according to the present invention. FIG. 3 is a time chart showing the position of the block delimiter 9 and the operation of the print head. 1...Print data source 2...Image buffer 3.
...Decoder 4...Block length memory 5...Voltage drop detection circuit 6...Print data length memory 7...
-Several circuits 8...Voltage drop control circuits 1, 9
...Print head movement circuit 10...Print head drive circuit layer 2111i 7 2 Dt LDn 8 3 [

Claims (1)

[Claims] 1. In a dot printer that prints characters, symbols, etc. by a combination of a plurality of dots given by a print head, there is a means for detecting a voltage drop in the drive power supply of the print head and a memorization of the delimitation of one block of data to be printed. When printing data with a high printing density, the printing method has a means for counting the length of printed data in a block, and a means for detecting from the count result that up to the division of one block has been printed. A dot printer characterized in that it detects a voltage drop at the timing of one block of data, temporarily stops printing, and resumes printing from the printing stop position after the voltage is restored.