JP3572854B2 - Inkjet printer and damper - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inkjet printer that performs a main scanning operation by reciprocating a carriage, and more particularly to a technique for stabilizing a main scanning operation when ink is supplied to a print head using an ink supply tube.
[0002]
[Prior art]
As an inkjet printer that performs a main scanning operation by reciprocating a carriage, for example, a serial scan type inkjet printer as shown in FIG. 7 is known. FIG. 7 is a perspective view of a main part showing a configuration example of this ink jet printer, and clarifies the positional relationship between the members. The illustrated inkjet printer 10 includes a frame 2, a guide rail 3, a carriage 4, a print head 5, an ink cartridge 6, and an ink supply tube 7, and feeds a print sheet S serving as a print medium by a transport mechanism (not shown). And print.
[0003]
The frame 2 fixes the two guide rails 3 in the main scanning direction. The guide rails 3 are used when the carriage 4 reciprocates in the main scanning direction (left and right directions in FIG. 7) by a drive mechanism (not shown). In addition, the carriage 4 is slidably supported. The print head 5 is provided integrally below the carriage 4 and prints on the print paper S by discharging ink from a plurality of inkjet nozzles. The ink cartridge 6 is an ink storage tank for storing ink ejected from the print head 5. The ink supply tube 7 is an ink flow path attached to one end of the carriage 4 for supplying the ink stored in the ink cartridge 6 to the print head 5.
[0004]
Although not shown, a damper is interposed between the ink supply end of the ink supply tube 7 and the print head 5 so as to absorb the fluctuation of the ink when the carriage 4 reciprocates. . The structure of this damper is as shown in FIGS. 8 (a) and 8 (b). That is, this type of damper 40 is formed by enclosing a film pack 42 for storing ink in an internal space of a box-shaped housing 41. An ink supply port 43 is formed on one of both wide surfaces of the housing 41, and an ink discharge port 44 is formed on a lower thickness surface of the housing 41.
[0005]
The ink supplied from the ink supply tube 7 is guided from the ink supply port 43 to the film pack 42, where it is stored until it reaches a predetermined amount. Air is removed from the inside of the film pack 42, and pressure is applied from the outside as the amount of stored ink increases, and this pressure causes the stored ink to be discharged from the ink discharge port 44 toward the print head 5. It has become. With the damper 40 having such a structure, it is possible to absorb the fluctuation of the ink during the reciprocation of the carriage 4 and to stably supply a predetermined amount of the ink to the print head 5.
[0006]
In the inkjet printer 10 having the above configuration, when a print request command or data (hereinafter, print data) is sent from the outside, the inkjet printer 10 prints a predetermined character or image based on the sent print data. Print on paper S. More specifically, the carriage 4 is driven in the main scanning direction while the printing paper S is fed at a predetermined pitch in the sub-scanning direction orthogonal to the main scanning direction, and the carriage 4 reciprocates on the guide rail 3. When the carriage 4 reciprocates, ink is ejected from the print head 5 to the printing paper S at a predetermined timing. By repeatedly performing such a control operation, the inkjet printer 10 performs printing.
[0007]
By the way, the ink stored in the ink cartridge 6 needs to be completely shut off (gas barrier) from the outside air due to its nature. The gas barrier property is a condition required also for the ink supply tube 7 serving as an ink flow path. Further, in order to secure a stable flow path, the ink supply tube 7 is required to have a certain "stiffness", that is, a bending rigidity. For this reason, the ink supply tube 7 generally has a certain level of gas barrier properties, for example, by having a two-layer structure of nylon and polyester, and has a predetermined bending rigidity by adjusting hardness during manufacturing. Was.
[0008]
[Problems to be solved by the invention]
However, the conventional inkjet printer 10 has the following problems.
[0009]
The first problem is that since the ink supply tube 7 attached to one end of the carriage 4 has a predetermined bending rigidity, a load is intensively applied to the tube attachment portion of the carriage 4, and the amount of the load is reduced by the carriage. 4 greatly varies depending on the traveling position.
[0010]
The load and load amount applied to the carriage 4 will be described in detail. FIG. 9 is a diagram illustrating an example of a change in the shape of the ink supply tube 7 with respect to the carriage position. In FIG. 9, reference numeral 4a denotes a carriage located at the rightmost end on the guide rail 3, 4b denotes a carriage located at the center on the guide rail 3, and 4c denotes a carriage located at the leftmost end on the guide rail 3.
[0011]
Since the ink supply tube 7 has a predetermined bending rigidity, the amount of load applied to the carriage 4 changes depending on the radius of curvature. For example, in FIG. 9, when the carriage 4 (4a) is located at the rightmost end, the radius of curvature is maximum, so that the bending rigidity of the ink supply tube 7 is minimum and the load on the carriage 4 is minimum. Then, as the carriage 4 travels in the left end direction in FIG. 9, the radius of curvature of the ink supply tube 7 gradually decreases, and accordingly the bending rigidity increases, so that the load applied to the carriage 4 also increases. Due to such a variation in the load amount, the main scanning operation of the carriage 4 becomes unstable, and in the worst case, the printing is disturbed. In particular, in the case of a color inkjet printer, a plurality of ink cartridges and an ink supply tube are required, so that the above problem becomes more remarkable.
[0012]
A mechanism for solving such a problem is disclosed in Japanese Patent Application Laid-Open No. 62-152885 (recording apparatus). FIG. 10 is a schematic view showing this conventional mechanism, and for convenience, the same elements as those in FIG. 7 are denoted by the same reference numerals. In this conventional mechanism, the radius of curvature of the ink supply tube 7 during movement of the carriage 4 is kept substantially constant by providing the attachment member 20 that supports at least one of the ends of the ink supply tube 7 so as to be displaceable. As a result, the load fluctuation applied to the carriage 4 is reduced, and the main scanning operation of the carriage 4 is stabilized.
[0013]
However, in the case of the mechanism shown in FIG. 10, although a required effect can be expected, a mounting member 20 for supporting at least one of the ends of the ink supply tube 7 in a displaceable manner is indispensable. Needs to be fixed to at least one of the ends of the ink supply tube 7, which causes another problem that the assemblability is poor.
[0014]
The second problem is that the conventional damper 40 provided on the carriage 4 cannot be used for a color ink jet printer as it is. That is, in the conventional damper 40, as shown in FIG. 8, since the ink supply port 43 is formed on the wide surface side, the mounting position of the ink supply tube is limited. Will be difficult to place. In addition, when a plurality of components are arranged, the size of the carriage becomes large, and the driving accuracy of the carriage by the carriage driving mechanism becomes a problem. Therefore, in the case of a color inkjet printer, it is necessary to prepare a damper having a shape different from that of a monochrome printer, and cost reduction cannot be achieved.
[0015]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved ink jet printer that stabilizes a main scanning operation by suppressing a load variation on a carriage without using a special attachment member that affects an assembling property.
[0017]
[Means for Solving the Problems]
In order to solve the above problems, an inkjet printer according to the present invention has a plurality of print heads for discharging ink, and the plurality of print heads are arranged in a main scanning direction, and are integrated with each print head in the main scanning direction. A carriage that reciprocates in the print area, a plurality of ink cartridges that are arranged outside the print area in the main scanning direction and store ink to be supplied to each of the print heads, and one end of each of the plurality of ink cartridges. And a first group and a second group of ink supply tubes, the other ends of which are connected to the print head, wherein the first and second ink supply tubes are in opposite directions within the carriage scanning area. So as to enter the carriage from the side opposite to the main scanning direction and supply ink to the print head. Characterized in that it is continued.
Further, the plurality of ink cartridges are arranged in two groups of one end side and the other end side in the main scanning direction.
Further, the ink supply tubes of each group are configured such that the ink supply ends enter the carriage from positions symmetrical with respect to the center of gravity of the carriage.
Further, the amount of load applied to the carriage by the ink supply tubes of one group when the carriage travels in the forward path, and the amount of load applied to the carriage by the ink supply tubes of the other group when the carriage travels in the return path. It is characterized in that it is configured to have the same amount.
Further, an ink discharge tube for discharging ink discharged by the cleaning operation of the print head is attached to the carriage together with an ink supply tube of any group.
Further, dampers of the same shape are interposed between the ink supply end of each ink supply tube and the corresponding print head, and each damper has a film pack for storing ink, and at least a vertical thickness surface. A thin box-shaped casing for enclosing a film pack, and an ink supply port for guiding ink supplied from the ink supply end to the film pack is formed on an upper thickness surface of the casing; An ink outlet for guiding the ink stored in the film pack to the print head is formed on a lower thickness surface of the body and on a diagonal line with respect to the formation part of the ink supply port. Features.
[0018]
The ink supply tubes of the respective groups are configured such that the ink supply ends enter the carriage from positions symmetrical with respect to the center of gravity of the carriage, and one of the ink supply tubes when the carriage travels forward. It is preferable that the load applied to the carriage by the ink supply tube of the group is the same as the load applied to the carriage by the ink supply tube of the other group when the carriage travels backward. .
[0019]
In another inkjet printer according to the present invention, dampers having the same shape are interposed between the ink supply ends of the respective ink supply tubes and the corresponding print heads. Each damper has a film pack for storing ink, and a thin box-shaped housing having at least upper and lower thickness surfaces and enclosing the film pack. An ink supply port for guiding ink supplied from a supply end to the film pack is formed, and a portion of the lower thickness surface of the housing that is diagonal to a portion where the ink supply port is formed includes the film supply port. An ink outlet for guiding the ink stored in the pack to the print head is formed.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 1 is a perspective view illustrating a main configuration of a color inkjet printer according to an embodiment of the present invention. For convenience, the same components as those of the conventional ink jet printer shown in FIG. 7 are denoted by the same reference numerals.
[0023]
The ink jet printer 1 of the present embodiment performs color printing using four color inks of black, cyan, magenta, and yellow, and includes two guide rails 3 in a frame 2 and guide rails 3. The four print heads 5a, 5b, 5c, and 5d are provided near the carriage 4 supported in the main scanning direction, and each print head 5 is provided with ink supply tubes 7a, 7b, and 7c from ink cartridges 6a, 6b, 6c, and 6d. , 7d supply the ink of the corresponding color. That is, the color inkjet printer 1 supplies ink to one carriage 4 using a plurality of ink cartridges 6a to 6d.
[0024]
The ink supply tubes 7a to 7d attached to the respective ink cartridges 6a to 6d are made of the same material, that is, have the same bending rigidity. The first group of ink supply tubes 7a and 7b and the second group of ink supply tubes 7c are used. , 7d. The ink supply tubes 7a, 7b, 7c, 7d (hereinafter, collectively referred to as the ink supply tubes 7) of each group are arranged such that the respective ink supply ends thereof are opposed to each other from the side opposite to the running direction of the carriage 4. 4, and is mounted so as to supply ink via a damper to a print head located at a position distant from the direction of entry.
[0025]
FIG. 2 shows an example of an attachment mode of the ink supply tube in this case. FIG. 2A shows an example in which the ink supply tube 7 is directly attached to the corresponding damper 8a, 8b, 8c, 8d (hereinafter, collectively referred to as the damper 8), and FIG. Is an example of being attached to the damper 8 via the tube buffer 9, and any of them may be adopted. The point is that the respective ink supply ends of the ink supply tubes 7a and 7b of the first group and the ink supply tubes 7c and 7d of the second group are mounted at positions symmetrical with respect to the center of gravity of the carriage 4. To
[0026]
FIG. 3A is a transparent perspective view of the damper 8, and FIG. 3B is a transparent front view. All of the dampers 8 have the same shape and structure. A film pack 82 for storing ink is sealed in an internal space of a thin box-shaped housing 81 having upper and lower thickness surfaces and left and right thickness surfaces. Become. An ink supply port 83 is formed on the upper thickness surface of the casing 81, and an ink discharge port 84 is formed on a lower thickness surface on a diagonal line with respect to the formation portion of the ink supply port 83. The ink discharge port 84 is of a detachable connector type with respect to the corresponding print heads 5a to 5d (hereinafter, collectively referred to as the print head 5), and is mounted simply by being pushed into the print head 5 from a predetermined direction. I can do it.
[0027]
The ink supplied from the ink supply tube 7 is guided from the ink supply port 83 of the damper 8 to the film pack 82, where it is stored until it reaches a predetermined amount. Air is removed from the inside of the film pack 82, and pressure is applied from the outside as the amount of stored ink increases, and this pressure causes the stored ink to be discharged from the ink discharge port 84 toward the corresponding print head 5. It has become so.
[0028]
With the damper 8 having such a structure, it is possible to absorb the fluctuation of the ink during the reciprocation of the carriage 4 and to stably supply a predetermined amount of the ink to the print head 5.
[0029]
In the damper 8 according to the present embodiment, the ink supply port 83 is formed on the upper thickness surface of the housing 81 and the ink discharge port 84 is formed at a predetermined portion on the lower thickness surface. Mounting becomes easy, and the flow of ink in each damper 8 becomes smooth. Further, the overall thickness of the damper 8 can be made smaller than that of a conventional damper of this type, and as shown in FIG. 4, the carriage 4 is in a state where the wide surfaces of the plurality of dampers 8 are in contact with each other. Since the carriage 4 can be disposed above, the entire carriage 4 can be made compact. Needless to say, the damper 8 can be used not only in a color inkjet printer but also in a monochrome inkjet printer under the same conditions.
[0030]
Next, the operation of the color inkjet printer 1 of the present embodiment, in particular, the effect of the ink supply tube on the change in the position of the carriage 4 will be described with reference to FIG. In FIG. 5, four ink tubes are represented by two ink supply tubes 71 of a first group and an ink supply tube 72 of a second group for convenience, and illustration of the ink cartridge 6 is omitted.
[0031]
FIG. 5A shows an example of the shape of the ink supply tubes 71 and 72 when the carriage 4 is located at the rightmost end of the guide rail 3. FIG. 5B shows the carriage 4 located at the center on the guide rail 3. FIG. 5C shows an example of the shape of the ink supply tubes 71 and 72 when the carriage 4 is located at the leftmost end on the guide rail 3.
[0032]
Since the ink supply tubes 71 and 72 in each group have a predetermined bending rigidity, the radius of curvature drawn by the ink supply tubes 71 decreases as the carriage 4 travels from the right end position to the left end position in FIG. Conversely, the ink supply tube 72 has a large radius of curvature.
[0033]
FIG. 6 is a diagram showing the relationship between the traveling position of the carriage 4 and the load (sliding load) at each position. In the drawing, a thin broken line indicates the load due to the ink supply tubes 71 of the first group, a thin solid line indicates the load due to the ink supply tubes of the second group, and a thick solid line indicates the load due to the ink supply tubes 71 and 72 of the first and second groups. Quantity. For reference, an example in which all the ink supply tubes 71 and 72 are attached to one end of the carriage 4 (n-digit side of the print area) is shown by a thick broken line.
[0034]
As is apparent from FIG. 6, as the carriage 4 travels in the direction from the first digit to the nth digit of the print area, the load applied to the carriage 4 increases due to the bending rigidity of the ink supply tubes 71 of the first group. Conversely, due to the bending stiffness of the ink supply tubes 72 of the second group, the load applied to the carriage 4 decreases as the carriage 4 travels from the first digit to the nth digit. Since the carriage 4 is subjected to the load by both the ink supply tubes 71 and 72, the carriage 4 eventually travels in the direction from the first digit to the nth digit, so that a substantially uniform load as shown by the thick solid line is obtained. The carriage 4 is involved. This relationship is the same when the carriage 4 travels from the nth digit to the first digit.
[0035]
That is, although the load fluctuation occurs in the ink supply tubes of only one group, the load is changed by attaching the ink supply tubes 71 and 72 of the first and second groups respectively to positions symmetrical with respect to the center line of the carriage 4. Fluctuation can be suppressed. As a result, it is possible to eliminate a factor that makes the main scanning operation of the carriage 4 unstable.
[0036]
As described above, according to the present embodiment, it is possible to stabilize the main scanning operation by reducing the load variation during the traveling of the carriage without requiring a special mounting member unlike the conventional mechanism.
[0037]
In the present embodiment, an example in which the number of the ink supply tubes of the first and second groups is set to two has been described. However, any structure may be used as long as the load variation applied to the carriage 4 can be suppressed. The number of ink supply tubes in the group is not necessarily limited to two, and can be set to any number. That is, one color ink may be supplied to the print head 5 by a plurality of ink supply tubes, or one group may be formed by one ink supply tube and two ink supply tubes. .
[0038]
Further, in the present embodiment, four ink supply tubes having the same bending rigidity are divided into two groups, each of which is disposed at a position symmetrical with respect to the center line of the carriage 4, so that the load applied to the carriage 4 can be reduced. Although the balance is maintained, when ink supply tubes having different bending stiffnesses are mixed, the load amount may be balanced by distributing and attaching each ink supply tube so as to divide the total bending stiffness into two. In some cases, dummy tubes may be arranged in either group. In addition, not only an ink supply tube for supplying ink for printing but also an ink discharge tube for discharging, for example, discharged ink generated by a cleaning operation of the print head 5 may be added to any group.
[0039]
【The invention's effect】
As is apparent from the above description, according to the present invention, in an ink jet printer that supplies ink using an ink supply tube, load fluctuation during carriage running is suppressed without providing a special member, and the main scanning operation is performed. Has the effect of stabilizing.
[0040]
Further, according to the damper of the present invention, it is possible to unify the mounting positions of the ink supply tubes and to prevent the carriage size from being enlarged when a plurality of ink supply tubes are arranged.
[Brief description of the drawings]
FIG. 1 is an external perspective view illustrating a configuration example of an inkjet printer according to an embodiment of the present invention.
FIGS. 2A and 2B are diagrams illustrating an example of an attachment mode of an ink supply tube, in which FIG. 2A illustrates an example in which the ink supply tube is directly attached to a corresponding damper, and FIG. This is an example of attachment to a damper.
3A is a transparent perspective view of the damper, and FIG. 3B is a transparent front view.
FIG. 4 is an explanatory view showing a state in which a plurality of dampers are arranged on a carriage.
FIG. 5 is a diagram showing a process of changing the shape of an ink supply tube with respect to a carriage position according to the embodiment.
FIG. 6 is an explanatory diagram showing a relationship between loads applied to a carriage by an ink supply tube.
FIG. 7 is a perspective view of a main part showing a configuration example of a conventional ink jet printer.
8 (a) is a perspective view of a conventional damper, and FIG. 8 (b) is a transparent front view.
FIG. 9 is a diagram showing a process of changing the shape of an ink supply tube with respect to a carriage position in this type of conventional printer.
FIG. 10 is a schematic view showing a conventional mechanism for suppressing a load variation applied to a carriage.
[Explanation of symbols]
1, 10 Inkjet printer 2 Frame 3 Guide rails 4, 4a, 4b Carriage 5, 5a-5d Print head 6, 6a-6d Ink cartridge 7, 7a-7d Ink supply tube 71 First group ink supply tube 72 Second group Ink supply tubes 8, 8a to 8d, 40 Damper 9 Tube buffer 20 Tube mounting members 81, 41 Damper housings 82, 42 Film packs 83, 43 Ink supply ports 84, 44 Ink discharge ports S Printing paper

Claims (6)

A plurality of print heads for discharging ink,
The plurality of print heads are arranged in the main scanning direction, a carriage that reciprocates in a printing area in the main scanning direction integrally with each print head,
A plurality of ink cartridges arranged outside the printing area in the main scanning direction and storing ink to be supplied to each of the print heads;
One end is connected to each of the plurality of ink cartridges, and the other end includes a first group and a second group of ink supply tubes connected to the print head ,
The first and second ink supply tubes are bent so as to be in opposite directions in the carriage scanning area, and enter the carriage from a side opposed to the main scanning direction to the print head. An ink jet printer connected to supply ink. 2. The ink jet printer according to claim 1, wherein the plurality of ink cartridges are arranged in two groups, one end side and the other end side in the main scanning direction. 3. The ink jet printer according to claim 2, wherein the ink supply tubes of the respective groups are configured such that the ink supply ends enter the carriage from positions symmetrical with respect to the center of gravity of the carriage. Printer. The same amount of load is applied to the carriage by the ink supply tube of one group when the carriage travels in the forward direction, and the same amount of load is applied to the carriage by the ink supply tube of the other group when the carriage travels in the return path. 4. The ink jet printer according to claim 2, wherein 5. The ink jet printer according to claim 2, wherein an ink discharge tube for discharging discharged ink generated by a cleaning operation of the print head is attached to the carriage together with an ink supply tube of any group. A damper of the same shape is interposed between the ink supply end of each ink supply tube and the corresponding print head, and each damper has a film pack for storing ink and at least an upper and lower thickness surface, And a thin box-shaped casing for enclosing the casing, and an ink supply port for guiding ink supplied from the ink supply end to the film pack is formed on an upper thickness surface of the casing, An ink outlet that guides the ink stored in the film pack to the print head is formed at a lower thickness surface and on a diagonal line with respect to the formation part of the ink supply port. The inkjet printer according to any one of claims 1 to 5, wherein: 』

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