JPH0418383A - Printing apparatus - Google Patents

Abstract

PURPOSE:To carry out printing without contaminating a printing surface by the blur transfer of ink by moving a printing head up and down in matching relation to the thickness of a printing line in a non-contact state with respect to a printing place in a medium following type printing apparatus. CONSTITUTION:A carrier 9 is pulled by a drive belt 8 to move on a support rail 10 to the left to ride on a printing medium 12. At this time, a roller 2 rides on the medium 2 at first and a roller link 4 inclines in a clockwise direction. A tension spring 15 moves in a groove 16 to the left to keep the tension same to that at the time when the roller link 4 is parallel. Tension links 6, 7 are pulled and compressed by the inclination of the roller link to pull the left of the belt 8 so as to raise the right thereof. Since the drive belt 8 moves to the left to receive the load in a laterial direction generated when the roller 2 rides on the medium as tension, the tension link is reversely pulled and the roller link 4 is ready to return to the original parallel state. When the tension of the tension spring 15 and that of the drive belt 8 are sufficiently strong, a slide 5 moves upwardly by the force of the roller link 4 ready to return to the parallel state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to stabilizing the height of a print head and a medium in a print mechanism of a printing device for bankbooks and the like.

[Conventional technology]

Conventional apparatuses, as described in Japanese Utility Model Application Laid-open No. 58-171359, have integrally equipped the print head with a pressing member that moves while pressing directly on the surface of the print medium, thereby maintaining a constant distance between the head and the medium. However, this method has the drawback that the pressing member comes into contact with the printing area immediately before and after the printing area, so that the printing surface becomes dirty or the ink immediately after printing is transferred.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration ink fading or transfer immediately after printing due to direct sliding on the printing medium surface, and there is a problem of staining of the printing surface. An object of the present invention is to prevent the medium from being soiled by contacting the medium at a location slightly distant from the printing location and by making point contact rather than surface contact.

[Means to solve the problem]

In order to achieve the above objective, rollers that detect the height of the medium and move up and down according to the height are installed on both sides of the print head in a position outside the printing range within the print line, and the It was designed to imitate the.

Further, in order to make the medium contact surface as small as possible, the roller is tapered so that it makes point contact on the arc of the upper surface of the platen.

[Operation] The copying roller is attached to a link having a fulcrum at a position rearward away from the center line of the print head, and the link is connected to a drive mechanism that drives the print head.

Rotation of the drive mechanism in either direction causes the link to rotate in a certain direction and be pressed against the media. At this time, the other roller rotates in a direction away from the medium due to the rotation of the link. As a result, the copying roller always presses the medium on either side of the print head, making it possible to print on the same line with different thicknesses.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows a print head 1, a carrier 9 to which it is attached and moves in the printing direction, a drive belt 8 that transmits the driving force to move the carrier, and a left belt that transmits the force to move the print head up and down in accordance with the thickness of the medium. The right copying rollers 2 and 3, the roller link 4 that attaches them, the print head that is connected to it with rotational support, and the slide 5 that moves up and down on the carrier, and the drive belt that is attached to both sides of the carrier and adjusts the inclination of the roller link. The tension spring 15, which is located between the left and right tension links 6°7, the slide and the roller link, moves within the groove 16 of the roller link due to the difference in tension due to the inclination of the roller link, and applies a specified pressure to the printing surface. FIG. 3 is a schematic front view of a configuration consisting of a spring 11 for pressing. FIGS. 2 and 4 are diagrams showing the operation.

Carrier 9 is pulled by drive belt 8 and supports rail 10
It moves to the left and tries to land on top of the print medium 12. At this time, the roller 2 first tries to ride on the medium 12, and therefore the roller link 4 is tilted clockwise.As a result, the tension spring 15 moves to the left in the groove 16 and maintains the same tension as when it is parallel.

The tension link 7 is pulled by the inclination of the roller link, and the tension link 7 is compressed, so that the left side of the drive belt 8 is pulled and the right side is pushed up. The drive belt 8 moves to the left and receives the lateral load as tension when the roller 2 rides on the medium, so the tension link 6 is pulled in the opposite direction and the roller link 4 attempts to return to its original parallel position. If the tension between the tension spring 15 and the drive belt is strong enough, the slide 5 will move upward due to the force that causes the roller link 4 to return to parallel. This makes it possible to perform a medium tracing method by reducing disturbances in the traveling speed due to lateral impacts caused by steps in the carrier moving direction.

Furthermore, as shown in the cross section I-1 in FIG. 3, the copying roller is located at a distance from the center of the print on the print medium surface on the upper surface of the platen, front and rear, so that it does not contact the printing area and does not stain the print surface.

Furthermore, by using a taber roller as the copying roller, it comes into point contact with the medium, and the printable range can be expanded. Also, by considering the distance between the copying rollers 2 and 3, it is possible to print near the crease of media with different thicknesses in the same line, such as a bankbook with left and right openings, and it is also possible to print on multiple different media in the same line. Become.

〔Effect of the invention〕

According to the present invention, the print head can be moved up and down according to the thickness of the line to be printed without contacting the place to be printed in a media-copying type printing device, so that the printing surface can be prevented from being smudged by blurred transfer of ink, etc. This has the effect of allowing printing without any problems.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of the printing mechanism section of an embodiment of the present invention;
Figures 2 and 4 are enlarged views of the schematic front view shown in Figure 1 when the medium is on the ground, and Figure 3 is an enlarged view of 1-1i in Figure 2.
It is a J sectional view. 1...Print head, 2...Left copying roller, 3...
Right copying roller, 4... Roller link, 5... Slide, 6... Left tension link, 7... Right tension link, 8... Drive belt, 9... Carrier, I
O...Support rail, 11...Spring, 12
...Print medium, 13...Roller link shaft, 14...
・Platen, 15...Tension spring, 16・
...Roller link groove.

Claims (1)

[Claims] 1. The printer has a print head and a carrier that moves along the rail in the direction of the print line, and a drive device to move the carrier. In a printing device that prints while maintaining a constant distance between the printing surface and the print head, the print head is placed on both sides of the print head, away from the print range in the front or rear direction of the line in the same direction as the carrier running direction, and is attached to the carrier. A copying member is attached to a member that moves the print head in a direction perpendicular to the printing surface and moves in the direction of the media thickness according to the thickness of the medium by rotational support, and a drive belt that drives the carrier and the left and right positions on both sides of the copying member. The left and right positions are connected so as to cross each other, and the rotational force when the copying member rides on the medium is transmitted as a load toward the center of the carrier to the connection point with the drive belt on the side in the direction of carrier movement, which is opposite to the direction of movement. At the connecting point on the side, there is a pair of connecting members that transmit the load in the direction away from the carrier, and a member that moves the copying member and the print head in a direction perpendicular to the printing surface. The member is movable in the left-right direction, and due to the rotation of the copying member that rides on the medium, the copying member is moved toward a higher left-right rotation position due to a tension difference, and is balanced with the tension of the drive belt transmitted to the connecting member to return the copying member to a parallel state. A printing device characterized by having a spring that applies force.