JPH04102852U - Print density adjustment device for impact printers - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a print density adjustment device for an impact printer that finely adjusts print density according to the number of copies of a print medium and the thickness of the medium. [Configuration] Eccentric cam 3 on shaft 2 of print density adjustment lever 1
and install encoder 7. When the print density adjustment lever 1 is rotated, the eccentric cam 3 is rotated to deflect the bracket 5 of the platen 4 and change the distance between the platen 4 and the print hammer 6. At the same time, the encoder 7 detects the rotation angle of the print density adjustment lever 1, a print hammer drive current is created according to the detection signal, and the print hammer 6 is controlled by the print hammer drive current to copy the print medium. Optimal printing is performed according to the number of sheets and the thickness of the medium.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a printing hammer bank in which a plurality of printing hammers are arranged in one horizontal row or in several horizontal rows. This relates to an impact printer that prints by moving it laterally using an eccentric cam, etc. be.

0002

[Conventional technology]

Conventional printers of this type print according to the thickness of print media such as single sheets and continuous sheets. Equipped with a setting device to set the distance between the hammer and the platen. This setting device is shown in Figure 1. As shown in the figure, the plate is adjusted by an eccentric cam 3 fixed to the shaft 2 of the print density adjustment lever 1. The distance between the platen 4 and the printing hammer 6 is changed by deflecting the bracket 5 that supports the platen 4. It is something that makes you change your mind. The printing medium is the printing hammer 6 and platen 4 (rubber roll). ), and printing is performed using the platen 4 as a base.

0003

[Problem that the idea aims to solve]

In recent years, line printers have been used as printing devices for printing continuous forms made by stacking multiple sheets of printing media. It's becoming more and more common. Particularly in the distribution industry, information about a single item is transmitted to many departments. Copying media is frequently used due to the need to store data. For this reason, copy media is required for line printers. High density printing performance is required when printing on the body. In response to such requests, printing Improvements in the physical properties of the hammer have improved the high-density printing performance of copy media. but , since this improvement is simply a method of increasing the printing pressure, the printing density when using a single sheet of media is has also been improved, so on thin media, printing marks may remain on the media after printing, or printing may be difficult. Problems such as increased noise and faster wear of the ink ribbon occurred.

0004

[Means to solve the problem]

This invention was made to solve the above problem, and the print density adjustment lever Attach an encoder to detect the rotation angle of this lever and adjust it to the thickness of the printing medium. The distance between the printing hammer and the platen, which was set by The printing hammer can be driven optimally depending on the thickness of the printing medium.

[0005]

[Effect]

Move the print density adjustment lever according to the number of copies of the print medium you are trying to print on. to set the distance between the printing hammer and the platen. Encodes the rotation angle of this lever. The drive current of the printing hammer is controlled based on the value of this rotation angle, and the Decrease print density for dark media and increase print density for copy media .

[0006]

【Example】

FIG. 2 shows an embodiment of the present invention, in which the print density adjustment lever 1 is adjusted according to the number of copies to be made. By setting , the eccentric cam 3 is rotated to move the platen 4, and the platen This is similar to the conventional device shown in Fig. 1 in that the distance between 4 and the printing hammer 6 is adjusted. However, in the present invention, an encoder 7 is connected to the shaft 2 of the print density adjustment lever 1, and this encoder 7 is connected to the shaft 2 of the print density adjustment lever 1. The rotation angle of the lever 1 is detected by the encoder 7, and the impulse current is adjusted according to the detected value. Therefore, the printing hammer 6 is controlled. Figure 3 shows a block diagram of the printing hammer drive current generation circuit, and 8 is the rotation angle. 9 is a printing density calculation circuit, and 10 is a printing hammer drive current control circuit. Figure 4 shows the relationship between the number of copies of the print medium, the rotation angle of the encoder 7, and the print density. .

[0007]

[Effect of the idea]

According to the present invention, the setting of the print density according to the number of copies of the print medium can be set as compared to the conventional method. Move the print density adjustment lever 1 to set the distance between the print hammer 6 and the platen 4 in the same way as above. At the same time, the print hammer drive voltage is activated by the output signal of the encoder installed in the setting device. Since the printing operation is performed by controlling the flow, it is possible to match the number of copies and the thickness of the printing medium. You will be able to make more detailed settings. As a result, after printing on thin media, The printed characters may leave marks on the media, the printing sound may become louder, or the ink ribbon may disappear. Problems such as early wear and tear are eliminated.

[0008]

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional print density adjustment device.

FIG. 2 is a perspective view of essential parts of an embodiment of the present invention.

FIG. 3 is a block diagram of a printing hammer drive current generation circuit in an embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the number of copies of a print medium, the rotation angle of an encoder, and print density.

[0009]

[Explanation of symbols]

1 Print density adjustment lever 2 axes 3 Eccentric cam 4 Platen 5 Bracket 6 Printing hammer 7 Encoder 8 Rotation angle calculation circuit 9 Print density calculation circuit 10 Printing hammer drive current control circuit

Claims (1)

[Scope of utility model registration request] [Claim 1] In an impact printer equipped with a setting device that sets the distance between a printing hammer and a platen according to the thickness of a printing medium such as a single sheet or a continuous sheet, an encoder is attached to this setting device, and the distance between the printing hammer and the platen is A printing density adjustment device for an impact printer, characterized in that the printing pressure of the printing hammer can be automatically adjusted according to the distance between the printing hammer and the platen.