JPS5853452A - Dot matrix printer - Google Patents

Abstract

PURPOSE:To enable to print in a constant density even when the distances between a platen and dot pins are different from each other, by a method wherein the period of time for which a dot pin is excited is changed in accordance with the distance between a circular platen and the dot pin. CONSTITUTION:A predetermined one of fixed period forming circuits 14a-14e is started by a signal, corresponding to a predetermined one of the dot pins, which is supplied from a printing control circuit 13, and an electromagnet corresponding to each of the dot pins is excited for the period of time for which an output is generated. The circuits 14a-14e are one-shot multivibrators, and according to the disposition of dot pins, the period of time formed by the circui 14a-14e is set to be longer as the distance between the platen 2 and the dot pin 4 is larger. Accordingly, it is enabled to print in a constant density by regulating the period of time of exciting, even when the distances between a platen and dot pins are different.

Description

[Detailed Description of the Invention] The present invention is applicable to line printers, serial printers, etc.
This print head 1 is a dot-bin driven i! which is made of a magnet or the like. 3 and dot bin 4 are the main components.This dot bin number has a plurality of dot bin numbers arranged in a vertical line or in a staggered arrangement at the tip a.In addition, this dot pin number is arranged close to each other. To do so.

The bin drive unit 3 is arranged so as to be spread out radially so that the drive unit can be accommodated therein.

The print head 1 as described above is now mounted on the spear 5 and is moved in the column direction as will be described later, and operates to sequentially print a predetermined pattern.

On the other hand, a platen 2 is disposed opposite the tip a of the print head 1. The platen 2 has an inside made of a hard material such as metal, and a surface lined with an elastic material such as rubber.

The platen head 1 and the platen 2 are arranged at a predetermined interval, and a paper 8 and an ink ribbon 9 are arranged between them, and by selectively driving the bin drive unit 3 according to a desired pattern, the bin numbers are projected. Ink ribbon 9 and paper B
A desired pattern is formed on the paper 8 by striking the platen 2 through the ? 1. Lint 〇 Figure 2 is a front view of the printer as shown in Figure 1. In Figure 1, the same symbols as in Figure 1 indicate the same items.

As shown in the figure, the platen 2 has a width corresponding to the maximum flame of the paper used, and the carriage 5 on which the matrix head 1 is mounted is guided by the guide bar 6 and the feed screw 'y
By rotating it, it moves to the left and right in the drawing, facing the platen 2.

These movements are performed by rotating the feed screw using the drive motor 0. These are all frame 1
It is fixed at 2.

The position of the matrix head 1 is detected by an encoder 11 directly connected to the feed screw 1, and is operated to form a desired dot pattern at a desired position. Such a matrix printer performs printing. In some cases, the following problems occurred.

That is, as shown in Fig. 3, the platen 2 and dot bin 4
The distance between the dot bins 4 and 5 differs depending on the dot bin 4. This is because 1 latte/2 is a circular platen.

Vertical dot bin? When arranged, the tip of the dot bin 4 at the center is closest to the platen 2 as shown in FIG. 1, and the farther the dot bin 4 is from the center, the farther the dot bin 4 is to the platen 2.

Therefore, since the dot pinch 41 is conventionally driven with the same excitation time, the pattern formed by the dot bins 4 located at a distance V from the center has a disadvantage that the density is thinner than that of the dot bins 4 located at the center. O Therefore, is the present invention a new dot matrix printer that eliminates the above drawbacks? The object is to provide a dot bin having a plurality of dot bins and a circular platen disposed opposite to the dot bins at a predetermined distance t, and between the plurality of dot bins and the circular platen. In a dot matrix printer that prints a predetermined pattern by impact printing in a dot matrix configuration by placing a medium in a dot matrix and selectively driving the plurality of dot pins, the number of dot bins is determined according to the distance between the circular platen and each of the dot bins. This can be achieved by changing the entire excitation time.

The present invention will be explained below with reference to the drawings.

FIG. 4 shows an embodiment of the dot matrix printer of the present invention. In the figure ↓ 3rd wife printing control circuit.

14a to 14etf constant time generation circuits, and 15 a dot bin drive circuit, respectively. In order to form a predetermined pattern by driving the dot bins, the print control circuit 13 issues a signal to excite the drive circuit 15t corresponding to the predetermined dot bin.

In general, a dot printer is equipped with a magnet 2 for each dot bin to drive the dot bins.

The generation circuits 14a to 14eQ are activated for a certain period of time. The fixed time generation circuits 14a to 14e are activated by a signal from the print control circuit 13 to generate an output for a predetermined fixed time, and are, for example, one-shot multi-bar breaker. The drive circuit 15 is driven by signals from the one-step time generating circuits 14a to 14e, and excites the magnet corresponding to the dot bin that is generating the output.

In the present invention, the excitation time of the magnet corresponding to each dot bin is changed according to each dot bin.

That is, the fixed time creation circuits 141L to 14e.

The preset time differs depending on the arrangement of each dot bin. That is, as the distance between the platen and the dot bin increases, the time width created by the one-step time creation circuits 14a to 14e increases.

With this configuration, the greater the distance between the platen and the dot bin, the longer the excitation time of the magnet for fully driving the dot bin.

With this configuration, in the present invention, even if the distance between the platen and the dot bin is different, the concentration can be kept constant by adjusting the excitation time.

[Brief explanation of drawings]

Figure g1 is a side view of the dot printer according to the present invention. lig diagram is a front view of the dot printer according to the present invention. FIG. 3 shows the relationship between the platen and dot pins of the dot printer according to the present invention, and FIG. 4 shows an embodiment of the dot printer according to the present invention. Furthermore, 1F in the diagram! Print head, 2 is a platen, 3 is a pin drive unit, 4 is a dot bin, 5 is a carriage,
6 is an indoor bar, M is a feed screw, 8 is paper, 9 is an ink ribbon, 10 is a drive motor, 11i encoder, 12 is a frame, 13 is a print control circuit, 14a to 14θ are fixed time creation circuits, FIG.

Claims (1)

[Claims] It has a plurality of O dot pins and a circular platen arranged opposite to the dot bins at a predetermined distance t, and a medium is arranged between the plurality of dot bins and the circular platen to select the plurality of dot bins. The dot matrix printer is driven to perform impact printing in a predetermined pattern T-dot matrix configuration, and the excitation time of the dot bins is varied according to the distance between the circular platen and each of the dot bins. dot matrix printer.