JPH02162058A - Impact dot line printer - Google Patents

Abstract

PURPOSE:To improve the points of size, durability, maintenance properties, cost and to accelerate an impact dot line printer by employing two rows of printing heads in a low resolution high speed printing mode, and employing one row of printing heads in a high resolution mode. CONSTITUTION:45 and 44 hammer pins are aligned in two rows in a zigzag shape, and a printing speed of 600 lines/min is realized in a data processing mode (DP mode) and 300 lines/min is realized in a near lever quality mode (NLQ mode) with the hammer pins. A hammer bank 2 is moved in one reciprocation of shuttle motion by the one revolution of a motor. In the case of the DP mode, the printing hammers are printed in two rows. Accordingly, 4 dot lines of vertical direction are printed by one revolution of the motor. Thus, vertical 7 dots are printed by the two revolutions, and the character space is fed by the following half revolution. Accordingly, the motor speed of the case of the printing speed of 600 lines/min becomes 600X2.5=1,500 RPM. In the case of the NLQ mode, one row of printing hammers are printed to print longitudinal 9 dots. Accordingly, the motor speed of the case of 300 lines/min becomes 300X(9/2+0.5)=1,500 RPM.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable resolution impact dot line printer.

[Conventional technology]

The print heads of variable resolution dot line printers currently in general use are of the single-row type, in which print heads are arranged in one horizontal row, as shown in FIG.

In this structure, multiple types of lateral resolution can be accommodated by appropriately selecting the pitch between the print heads. In addition, while the vertical direction can be handled by changing the paper feed resolution, a multi-row type or a staggered two-row type as shown in Figure 2 has been proposed for the print head of a fixed-resolution dot line printer. There is.

These print heads are reciprocated in the lateral direction by a shuttle drive mechanism illustrated in FIG. 3 to perform printing operations.

In the figure, l is a printing hammer, 2 is a hammer bank, 3 is a cam follower, and 4 is a cam.

Here, the assembly of print heads is called a hammer bank, and its reciprocating movement is called a shuttle.

Figure 4 shows the speed curve for the shuttle, and Figure 5-5 shows the speed curve for the shuttle.
@ shows the timing of printing and paper feeding during the reciprocating movement of the shuttle.

While the shuttle moves in one direction, the single-row type prints one dot line, and the staggered two-row type prints two dot lines. FIG. 5 shows the case of simultaneous two-dot line printing using a staggered two-row type.

A line feed between dot lines is performed during the return of the shuttle, but since the line feed between characters takes a long time and cuts into the next printing area, the printing operation is paused at this time.

In the case of a two-row type, the rotation speed of the shuttle drive motor can be lower than that of a one-row type.

[Problem to be solved by the invention]

Multi-rowing print heads in order to improve printing speed is an effective method in that the shuttle drive mechanism can be made smaller and lower in cost.

However, in the case of a multi-row head, the inter-row pitch is fixed, and although it is possible to vary the dots of the line feed method by using small paper feeds, etc., there are many constraints, and it is costly.
This is not practical in terms of speeding up.

As a recent trend in the European and American markets, it has become a requirement for dot printers to be able to switch the dot pitch so that one printer can be used for a wide variety of applications. Particularly in the case of printers that can also print graphics, the variable range of dot pitch required is wide, and the only way to achieve high speed was to use a single-line head. We were not able to obtain anything satisfactory in terms of cost.

[Means to solve the problem]

Alphanumeric impact dot line printers for the European and American markets have a dot pitch of about 50 to 150 dots/inch, and the required printing hammer is a Kanji printer, which has been put into practical use at a sufficient level for high-speed printing.

On the other hand, the shuttle drive mechanism currently faces bottlenecks in increasing speed due to size, durability, maintainability, and cost.

This invention was made to solve this problem.It uses staggered hammers, prints entirely with the hammers in high-speed printing mode, and keeps the shuttle drive acceleration sufficiently lower than in the case of a single-row hammer, allowing high-density printing. In this mode, only one row of hammers is used to switch the resolution.

〔Example〕

FIG. 6 shows an embodiment of the present invention, in which a hammer bin 1
1 has 45 and 44 pieces arranged in two rows in a staggered pattern.

Use this hammer pin in data processing mode (
A case will be described in which a printing speed of 600 lines/min is achieved in the DP mode (DP mode) and 300 lines/min in the near letter quality mode (NLQ mode).

In DP mode, the character dot matrix is 9 dots horizontally x 7 dots vertically, and the dot pitch is 60 dots/inch horizontally x 72 dots/inch vertically, and in NLQ mode, it is 13 dots x 9 dots.

100 dots/inch x 96 dots/inch.

The shuttle drive mechanism is based on a cam 4 fixed to a DC motor shaft.

It is assumed that with one revolution of the motor, the hammer bank 2 makes one reciprocating shuttle motion at a speed of a sine curve.

In the DP mode, the printing hammer prints in two rows, so one reciprocation of the hammer bank 2, that is, one rotation of the motor, can print four dot lines vertically, so two rotations can print seven dots vertically.
The dot characters are printed, and a line break is made between the characters in the second half of the rotation (see Figure 5).

Therefore, for a print speed of 600 lines/min, the motor speed is 600 x 2.5 = 150 ORPM.

In NLQ mode, printing is performed using only one row of printing hammers and 9 vertical dots are printed, so the motor speed at 300 lines/min is 300X (+0.5) = 15
It becomes 0ORPM.

The basic design considerations for increasing printing speed are the response frequency of the printing hammer and the maximum acceleration of the shuttle.

[Effects of the Invention] The present invention will now be described in detail in comparison with the conventional single-row type case shown in FIG.

Table 1 shows the results of determining the maximum frequency of the printing hammer and the maximum acceleration of the shuttle using the sine cam method when a sine cam was used in the shuttle drive mechanism.

From Table 1, the maximum response frequency of the printing hammer is the maximum response frequency of the hammer bank.Printing range per printing hammer...Staggered type?
, 62wm, single row type 3.81mm The values shown in Table 1 were calculated using the following formulas (1) and (2).

↑L: Shuttle return time...0.008 sec
g: Gravity unit...9800mm/sec" As shown in Table 1, in the case of an 89-piece staggered printing hammer, the maximum shuttle acceleration is 12g and the hammer bank weight is 1.2k.
g, the driving force by the cam is 14.4 kg, and the shuttle drive mechanism in this case can use existing low-cost, maintenance-free technology.

On the other hand, with the conventional single-row type, the maximum acceleration is 23g,
Since the cam mechanism is also complicated and requires oil lubrication, the competitiveness of the product is greatly reduced in terms of size, cost, and maintainability. The maximum frequency of printing hammers that can handle up to about 3.5 kg for Kanji printers have been put into practical use, and all types are at a level that causes no problems.

In addition, when using the staggered printing hammer in high resolution mode,
If only one row of print heads is used, there will be a difference in print performance, especially density, from the print head on the other side that is not being used due to wear of the rad pin tip for printing, so a means to switch the print head row to be used should be provided. It is also effective in extending the life of the print head.

[Brief explanation of the drawing]

Figures 1 and 2 are plan views showing the arrangement of printing hammers in a conventional device, Figure 3 is a front view of the printing hammer drive mechanism, Figure 4 is a speed curve for shuttle operation, and Figure 5 is a FIG. 6, which is an explanatory diagram of the printing operation in the case of a shuttle, is a plan view showing the arrangement of print heads in an embodiment of the present invention. 1... Printing pin 2... Hammer bank 3... Cam follower 4... Cam 11... Hammer pin 12... Hammer spring

Claims (2)

[Claims] (1) In a dot line printer with two rows of print heads arranged in a staggered manner, in low resolution high speed printing mode,
It uses two rows of printheads, but in high resolution mode,
An impact dot line printer characterized by using one row of print heads. (2) In a dot line printer with two rows of print heads arranged in a staggered manner, in high resolution mode, either one
An impact dot line printer that uses rows of print heads and has means for switching between rows of heads to equalize deterioration due to wear of the print heads.