JPH03211059A - Dot matrix type printing head - Google Patents

Abstract

PURPOSE:To realize a dot matrix printing head which has a simple structure and can perform impact printing and non impact printing by providing a nozzle block having ink chambers and nozzles arranged at certain positions so as to face to tips of impact wires, and attaching the nozzle block under conditions that a movable wall of the ink chambers faces to the tips of the impact wires. CONSTITUTION:A nozzle block 10 having ink chambers 14 is attached to the front end portion of an impact type printing head 4, and a movable wall 15 of the ink chambers 14 faces to tips of impact wires 13. When the impact wires 13 are driven, the movable wall 15 is depressed by the projection of the impact wires 13 and pressurizes the ink in the ink chambers 14 so as to discharge ink droplets from nozzles 16. Therefore, one-to-one correspondence between the driving operation of the wires 13 of the impact type printing head 4 and the discharging operation of the ink droplets is realized, and the same pattern of printing is formed by the ink droplets as the pattern of printing to be produced by the impact type printing head.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention relates to
- It is related to a lix-type print head, and has two printing methods: impact printing, which prints by impacting the tip of a wire on printing paper, and inkjet printing, which prints by jetting ink droplets onto printing paper. Regarding possible printheads.

(Prior art) There are impact type and non-impact type print heads used in printers for information processing equipment.Wire impact type print heads are widely used as impact type print heads, and non-impact type print heads are It is well known that one type of print head is an on-demand inkjet print head.

FIG. 6 schematically shows the structure of a wire impact print head, in which a wire is fixed to the tip of the armature 22 as the armature 22 is attracted to or separated from the yoke 23 by energization of the electromagnetic coil 21. 1
3 to perform impact printing. FIG. 7 schematically shows a piezo-type on-demand inkjet printing head, in which a pressure wave is generated in the ink chamber 14 each time the piezoelectric element 25 is energized. This is a structure in which ink droplets 18 are ejected. In addition to the piezo type described above, a bubble type is well known as an on-temant type inkjet print head.

(Problems to be Solved by the Invention) In impact printing using a wire impact print head, copy paper can be used as printing paper, and a wide range of paper qualities can be used. , the disadvantage is that the printing sound is noisy.

On the other hand, non-impact printing produces quiet printing, but has the disadvantage that the types of printing media are limited, such as the inability to print on copy paper. For example, if you need to print on multiple sheets of copy paper, such as a slip, impact printing is essential, but if you only need one hard copy, non-impact printing, which produces quieter printing, is preferable. .

However, with conventional devices, it has been impossible to perform printing by appropriately selecting impact printing or non-impact printing depending on the type of printing paper.

Therefore, an object of the present invention is to provide a print head capable of impact printing and non-impact printing with a simple structure.

(Means for Solving the Problems) The print head of the present invention is provided with a removable adapter at the tip of the impact print head 4 equipped with an impact wire 13, and by attaching this adapter, non-impact printing by inkjet is possible. making it possible.

That is, the print head of the present invention is an impact type print head 4 equipped with an electrically driven invac I wire 13.
and a nozzle block 10 having an ink chamber 14 with a movable wall 15, and the nozzle block 10 can be attached to and removed from the tip of the impact type print head 4. The ink chamber 14 and the nozzle 16 of the nozzle block 10 are arranged at a position opposite to the tip of the wire 13 of the impact print head 4, and the nozzle block 10 has a movable wall 15 of the ink chamber that is connected to the impact wire of the impact print head. It is attached facing the tip of the 4.

(Function) When printing on copy paper with a printer equipped with the print head having the above structure, impact printing is performed in the same manner as the conventional wire-in-back 1-type print head with the nozzle block 10 removed. When switching from impact printing to inkjet printing, the ink ribbon device 8 is removed, the impact print head 4 is moved backward, and a nozzle block 10 is attached to the tip thereof. The ink tank 9 that supplies ink to the nozzle block 10 may be installed in the space after the ink ribbon device 8 is removed.

The ink ribbon device 8 of the normal impact print head is
It is housed in a cartridge and can be easily replaced, so it is convenient to install an inkjet printing unit that integrates the nozzle block 10 and ink tank 9 in place of the cartridge. .

The nozzle block 10 attached to the tip of the impact type printing head 4 has a movable wall 15 of its ink chamber facing the tip of the impact wire 13, and
When driven, the movable wall 15 is pushed by its protruding action, pressurizes the ink in the ink chamber 14 facing it, and ink droplets 18 are ejected from the nozzle 16. Therefore, there is a one-to-one correspondence between the driving of the wire 13 of the impact-type print head 4 and the ejection of droplets from the ink chamber 14 of the nozzle block 10, resulting in a print pattern that is exactly the same as the print pattern formed by the impact-type print head. The pattern is nozzle block 10
It will be formed by ink droplets from.

(Embodiment of the Invention) FIGS. 3 and 4 are perspective views showing the print head mounting portion of a printer equipped with the print head of the present invention, in which 1 is a carrier running along a guide bar 2, and 3 is a carrier 1. 4 is a wire impact type I-type printing head, 5 is a fixing claw for fixing the impact type printing head 4 to the carrier 1, and 6 is a ribbon guide fixed to the carrier 1. A protrusion 7 is provided at the tip of the printing head 4 to serve as a mounting guide for the nozzle block described below.

Not shown in FIG. 3 is a ribbon cartridge 8 fixed with a bracket 3, 9 shown in FIG. This is the installed nozzle block.

As shown in FIG. 5, the nozzle block 10 has a recess 11 that fits into the tip of the impact print head 4, and a groove 12 that fits into the protrusion 7 is provided in this recess. 4J has been given. The nozzle block 10 is formed with an ink chamber 14 located on the extension of each wire 13 when attached to the tip of the impact print head 4, and the end of each ink chamber on the wire 13 side is made of silicone rubber. It is closed with a flexible partition wall 15 such as , and a nozzle 16 is opened on the side opposite to the wire. In order to attach the nozzle block 10 to the tip of the impact type print head 4, the impact type print head 4 is attached to the nozzle part of the nozzle block 10 with a thickness H (the first
It is necessary to move back by the distance shown in the figure. As a means for realizing this, for example, positioning holes (not shown) corresponding to positioning pins (not shown) when fixing the impact print head 4 to the carrier 1 can be placed in the forward position shown in FIG.
A structure is provided in which two locations are provided so that the print head 4 can be positioned between the backward position and the backward position shown in the figure, and a positioning mechanism using springs is used to bias and fix the print head 4 to the forward position and the backward position. It is possible to adopt a structure that enables this.

FIG. 3 shows an impact printing state, in which printing is performed by impacting the printing paper with the wire of the impact printing head 4 via the ink ribbon 17. FIG. 4 shows the state of inkjet printing. The ribbon cartridge 8 is removed from the state shown in FIG. 3, the impact print head 4 is moved to the retracted position, and the nozzle block 10 is installed in the space created by the retraction at the front end of the print head. The details of the relationship between the tip of the wire and the ink chamber of the nozzle block at this time are shown in FIG. The tip hits the movable wall 15 of the nozzle block facing it, deforms the movable wall toward the inside of the ink chamber 14, generates a pressure wave in the ink chamber 14, and ejects ink droplets 18 from the nozzle 16. . Then, by driving the wires in the same way as in the case of impact printing, ink droplets 18 are ejected from the ink chambers 14 corresponding to each wire 3, resulting in a character or figure pattern that is exactly the same as the pattern printed in impact printing. is formed by the ink droplet 18 on the printing paper.

(Effects of the Invention) The nozzle block of the present invention only has a movable wall that is pushed by the wire of the impact print head, and does not require an electric drive device itself, so its structure is extremely simple. . By attaching an ink block with such a simple structure to the tip of an impact-type print head, it is possible to convert the impact-type print head into an inkjet-type print head.For example, impact printing can be performed on copy paper. The effect is that impact printing and non-impact printing can be easily changed and used depending on the type of printing paper and printing suitability, such as performing non-impact printing when printing only one sheet. There is. Furthermore, since the same electric drive device is used for impact printing and non-impact printing, the structure and control of the drive system do not become complicated.

[Brief explanation of drawings]

1 to 5 are diagrams showing an embodiment of the present invention,
Fig. 1 is a sectional view of an impact-type print head and a nozzle block attached to its tip, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a printer device equipped with the print head of the present invention. FIG. 4 is a perspective view of the main part during impact printing, FIG. 4 is a perspective view during inkjet printing, and FIG. 5 is a perspective view showing the fitting structure between the nozzle block and the tip of the impact type printing head. FIG. 6 is a diagram schematically showing the internal structure of a wire impact print head, and FIG. 7 is a diagram schematically showing the internal structure of a conventional inkjet print head. In the figure, 4: Impact type printing head

Claims (1)

[Claims] The nozzle block (10) has an impact printing head (4) with an electrically driven impact wire (13) and a nozzle block (10) having an ink chamber (14) with a movable wall (15). ) ink chamber (14);
The nozzles (16) are arranged at positions corresponding to the tips of the wires (13) of the impact printing head (4), and the nozzle block (10) is removable from the tip of the impact printing head (4). A dot matrix print head characterized in that, when installed, the movable wall (15) of each ink chamber of the nozzle block faces the tip of the corresponding impact wire (13) of the impact print head.