JPH04173374A - inkjet recording device - Google Patents

Abstract

PURPOSE:To obtain an ink jet printer wherein strong rubbing of a printing paper and a paper guide against a head is prevented and turbulence in recording does not occur by providing a guide member for guiding movement of a carriage, a face for guiding the carriage in the direction that the head approaches the printing paper with respect to the guide member, and a guide section of the carriage for guiding so as to have looseness in the direction of moving away. CONSTITUTION:In a guide section 10, a contact section 11 contacts with a first guide member 6 and a looseness 12 is to be produced between the contact section 11 and the first guide member 6 at the reverse side. Accordingly, when a printing paper 2 and a paper guide plate 4 are rubbed strongly against a print head 1 by paper jam or paper float, forces to be received from the printing paper 2 and the paper guide plate 4 overcome the weight of a carriage 5 and the print head 1 so as to lift up the whole of the carriage 5 and can let the print head 1 go for a part of the looseness 12, so that the rubbing force of the printing paper 2 and the paper guide plate 4 against the print head 1 is reduced. Further, a position of a center of gravity 13 is changed so that the rubbing force against the print head 1 can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an inkjet recording apparatus, and particularly to a head positioning mechanism of an inkjet printer.

``Prior Art'' Conventionally, inkjet printers record information such as letters and pictures by colliding liquid ink with droplets of paper according to the information to be recorded as dots.

"Problem to be Solved by the Invention" The ejection of droplets from the print head of such an inkjet printer is easily affected by the condition of the head surface, and the printing paper and paper guide plate may be affected by the paper jam or paper floating of the printing paper. If the head is strongly rubbed by the head, the ejection state of the droplets changes due to small scratches on the head surface or changes in physical properties, resulting in disturbances in recording, which has been a problem.

The present invention was made in view of such problems, and
The objective is to provide an inkjet printer that does not cause disturbances in recording.

"Means for Solving the Problems" The inkjet recording device of the present invention includes a print head,
A platen that guides and positions the print paper in the printing portion of the print head, a paper guide plate that presses the print paper against the platen, a carriage that fixes the print head and is movable in the printing digit direction; A guide member that guides the movement of the carriage, a surface that guides the carriage in a direction in which the head approaches the printing paper with respect to the guide member, and a guide portion of the carriage that guides the carriage in a direction that moves away from the print paper with play. It is characterized by

"Function" According to the inkjet recording apparatus of the present invention, the backlash formed between the guide portion of the carriage and the guide shaft allows
This can prevent printing paper and paper guides from being strongly rubbed against the head.

"Embodiment" The basic structure and operation of the inkjet recording apparatus according to the present invention will be explained based on a first embodiment shown in FIG.

Reference numeral 1 in the figure is a print head that forms information such as characters and pictures on print paper 2 by ejecting droplets.

The printing paper 2 is guided by a platen 3, and is accurately positioned on a reference surface 5 on the platen 3 at the printing portion by the pressing force of a guide plate spring 9 attached to a paper guide plate 4. The carriage 5 is guided by a first guide member 6 and a second guide member 7, and scans the print head 1 in the printing column direction. At the same time, the carriage 5 securely fixes the print head 1. Furthermore, the guide section 10 of the carriage 5 has a position at least 1.5 times the length from the second guide member 7 to the printing part of the print head, with respect to the degree of freedom of rotation around the second guide member 7. There is a contact portion 11 with the first guide member 6, and the gap 8 between the print head 1 and the print paper 2 is precisely positioned by this lever ratio. The entire center of gravity 13 of the carriage 5 and the print head 1 is biased toward the print head 1 with respect to the line connecting the second guide member 7 and the first guide member 6. Therefore, in the normal state, the contact portion 11 of the guide portion 10 is the first
The guide member 6 is in contact with the guide member 6, and accurate positioning as described above is possible. On the other hand, on the opposite side, there is a first guide member 6
The structure is such that there is a play 12 between the two.

In this embodiment, if the printing paper 2 or the paper guide plate 4 is strongly rubbed against the print head 1 due to a paper jam or paper floating, the force received from the printing paper 2 or the paper guide plate 4 will be applied to the carriage 5. It is possible to overcome the weight of the print head 1 and lift the entire carriage 5, allowing the print head 1 to escape by the amount of backlash 12, thereby reducing the force of the print paper 2 and paper guide plate 4 rubbing against the print head 1, and further lifting the carriage 5. By changing the positions of the center of gravity 13 of the print head 5 and the print head l, the force that rubs the print head 1 can be controlled.

FIG. 2 shows a second embodiment according to the invention.

The guide part 10 of the carriage 5 has a positioning spring 14 and a spring holding member 15. Therefore, in a normal state, the contact part 11 is in contact with the first guide member 6 regardless of the position of the center of gravity of the carriage, and accurate positioning is possible. It is possible. On the other hand, on the opposite side, a play 12 is formed between the guide member 6 and the first guide member 6, as in the first embodiment.

In this embodiment, as in the first embodiment, the force received from the printing paper 2 and the paper guide plate 4 overcomes the pressing force of the positioning spring 14 and pushes the entire carriage 5, causing backlash 12.
Since the print head 1 can be released by up to 10 minutes, the force of the print paper 2 and paper guide plate 4 rubbing against the print head 1 can be reduced, and by changing the pressing force of the positioning spring 14, the force of rubbing the print head 1 can be reduced. can be managed.

FIG. 3 shows a third embodiment of the present invention.

As in the second embodiment, there is a positioning spring 14 and a spring holding member 15 in the guide portion 1o of the carriage 5, and as in the first embodiment, the entire center of gravity 13 of the carriage 5 and print head 1 is located at the second embodiment. It is biased toward the print head 1 side with respect to the line connecting the guide member 7 and the first guide member 6. Therefore, in a normal state, the contact portion 11 is in contact with the first guide member 6 due to both the position of the center of gravity of the carriage and the pressing force of the positioning spring, and accurate positioning is possible. On the other hand, on the opposite side, a play 12 is formed between the guide member 6 and the first guide member 6, as in the first embodiment.

In this embodiment, as in the first embodiment, the force received from the printing paper 2 and the paper guide plate 4 overcomes the pressing force of the positioning spring 14 and pushes the entire carriage 5, causing backlash 12.
Since the print head 1 can be released by up to 10 minutes, the force of the print paper 2 and paper guide plate 4 rubbing against the print head 1 can be reduced, and by changing the pressing force of the positioning spring 14, the force of rubbing the print head 1 can be reduced. can be managed.

"Effects of the Invention" As explained above, according to the present invention, even if the printing paper or paper guide plate is lifted up due to the paper jam or paper lifting of the printing paper, it is possible to reduce and manage the force that rubs the print head. Therefore, since it is possible to prevent small scratches on the head surface or changes in physical properties, it is possible to realize a stable inkjet recording apparatus that does not cause disturbances due to changes in the ejection state of droplets.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an apparatus showing one embodiment of the present invention, Fig. 2 is a block diagram of a second embodiment of the present invention, and Fig. 3 is a block diagram of a third embodiment of the present invention. . 1. Print head 4. ,,,paper guide plate 2,
,,,Printing paper 5. ,,,Carriage 3,,,
, platen 6. ,,,first guide member? ,,
, Second guide member 8, Gap (between head and platen) 9,...
Guide leaf spring 10, . . . Carriage guide portion 11, . . . Contact portion (carriage-first guide member) 1
2., backlash 14. ,,positioning spring 13
,,,center of gravity 15. ,,Spring holding member Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Claims] a print head, a platen that guides and positions the print paper in the printing portion of the print head, a paper guide plate that presses the print paper against the platen, and a paper guide plate that fixes the print head and is movable in the printing digit direction. a carriage, a guide member that guides the movement of the carriage, a surface that guides the carriage in a direction in which the head approaches the printing paper with respect to the guide member, and a guide portion of the carriage that guides the carriage in a direction that moves away from the print paper with play. An inkjet recording device comprising: