Printing apparatus

Abstract

There was a risk of the platen gap fluctuating. [Solution] The printing apparatus comprises a platen that supports a medium, a head that discharges liquid onto the medium supported by the platen, a sub-carriage that supports the head, a main carriage that supports the sub-carriage, and a position adjustment mechanism provided on the main carriage that can adjust the position of the sub-carriage in a direction that changes the distance between the platen and the head by adjusting the distance between the sub-carriage and the main carriage. The position adjustment mechanism consists of a rotating shaft and a receiving part that is inserted through the rotating shaft and receives the sub-carriage, and the receiving part is characterized in that its orientation does not change with the rotation of the rotating shaft.

Description

Technical Field

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[0001] The present invention relates to a printing apparatus.

Background Art

[0002] Conventionally, as shown in Patent Document 1, an apparatus for adjusting a so-called platen gap using a cam surface of an eccentric cam is known.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described apparatus, the cam surface formed of a curved surface and the cam follower portion are in contact with each other in a narrow range, and the contact position is likely to shift and become unstable, and there is a possibility that the platen gap may vary.

Means for Solving the Problems

[0007] 1.Printing device The following description of an embodiment of the printing apparatus 1 will be made with reference to the drawings. Directions in the drawings will be described using a three-dimensional coordinate system. For the sake of explanation, the positive direction of the Z axis will be referred to as the upward direction or simply up, and the negative direction as the downward direction or simply down; the positive direction of the X axis will be referred to as the right direction or simply right, and the negative direction as the left direction or simply left; and the positive direction of the Y axis will be referred to as the forward direction or simply forward, and the negative direction as the backward direction or simply backward.

[0008] As shown in Figure 1, the printing apparatus 1 houses a printing unit 2, a maintenance unit 50, and the like. The medium M is transported along a transport direction F from rear to front by a transport mechanism (not shown) including a transport motor and transport rollers. The medium M may be, for example, paper or a resin such as film. The medium M may be elongated and set at the rear of the printing device 1 in a rolled state. In this case, the printing device 1 may be equipped with a winding section (not shown) at the front, which is transported in the transport direction F by a transport mechanism, and the printed medium M is wound up by the printing unit 2.

[0009] Printing device 1 is an inkjet printer, a so-called large-format liquid ejection device capable of printing on media M of A1 size or larger. Printing device 1 may also be equipped with external components such as an ink tank capable of supplying liquid ink and a waste liquid tank (neither of which are shown in the figure). Furthermore, the printing apparatus 1 may be equipped with a drying unit (not shown), such as an infrared heater, to dry the liquid of the medium M that has been applied by printing.

[0010] The maintenance unit 50 includes a capping unit, a flushing unit, a suction unit, a wiping unit (all not shown), and the like. The maintenance unit 50 performs maintenance operations on the head 33, which will be described later and shown in Figure 2. The capping unit can cover and seal the nozzle surface 33a of the head 33 when printing is paused. The flushing unit can receive ink, which is liquid ejected from the nozzles (not shown) of the head 33. The suction unit can perform suction cleaning to remove ink from inside the nozzles of the head 33. The wiping unit can wipe the nozzle surface 33a of the head 33.

[0011] 2. Printing Unit The printing unit 2 will be described with reference to Figures 2 and 3. As shown in Figure 2, the medium M is supported by the platen P and transported along the transport direction F. The printing unit 2 has a first carriage 10 which is the main carriage, and a second carriage 30 which is the sub-carriage.

[0012] The first carriage 10 is supported so as to be movable by a carriage shaft 24. The first carriage 10 can be moved along the carriage shaft 24 in the scanning direction, which is the left-right direction, by a carriage motor (not shown). The first carriage 10 supports the second carriage 30. The second carriage 30 supports the head 33. As the first carriage 10 moves in the scanning direction, the second carriage 30 and the head 33 also move in the scanning direction.

[0013] The print head 33 has nozzles (not shown) that eject liquid ink onto the medium M. If the print head 33 has multiple nozzles, it is possible to eject multiple colors of ink. In this case, the print head 33 can eject not only CMYK (Cyan, Magenta, Yellow, Black) inks but also white ink, etc.

[0014] The nozzle surface 33a is the surface on the head 33 where the nozzle is formed and where the nozzle opens. The nozzle surface 33a faces downward and can face the platen surface Pa above the platen P. The distance PG, which is the distance between the head 33 and the platen P, is called the platen gap. Specifically, the distance PG is the distance from the nozzle surface 33a of the head 33 to the platen surface Pa of the platen P. Since the distance PG affects the print quality, it is configured to be adjustable by the first adjustment unit 11, as described later. The distance PG may also be the distance between the head 33 and the surface of the medium M supported by the platen P.

[0015] The platen P supports the medium M placed on its platen surface Pa as it is transported in the transport direction F. When the first carriage 10 moves in the scanning direction, the head 33 mounted on the second carriage 30 also moves in the scanning direction, and prints by ejecting liquid ink from above onto the medium M supported by the platen P. The print head 33, which moves while printing, is known as a serial print head.

[0016] Between the first carriage 10 and the second carriage 30 in the front-rear direction, a first stopper 40 is provided above and a second stopper 41 is provided below. The first carriage 10 and the second carriage 30 can contact the first stopper 40 and the second stopper 41. Note that the first stopper 40 and the second stopper 41 may be provided on either the first carriage 10 or the second carriage 30.

[0017] Furthermore, a first spring 42 is mounted above and a second spring 43 below between the first carriage 10 and the second carriage 30 in the front-rear direction. In the example shown in Figure 2, the first spring 42 and the second spring 43 are so-called tension coil springs. The first spring 42 and the second spring 43 exert a force that pulls the first carriage 10 and the second carriage 30 in the front-rear direction. In other words, the first spring 42 and the second spring 43 act to bring the first carriage 10 and the second carriage 30 closer together in the front-rear direction.

[0018] As described above, the first stopper 40, the second stopper 41, and the first spring 42 and the second spring 43 enable the first carriage 10 to support the second carriage 30. Specifically, the first carriage 10 can support the second carriage 30 movably. With such a configuration, as described below, the position of the second carriage 30 with respect to the first carriage 10 can be adjusted by the first adjustment unit 11 and the second adjustment unit 21 provided on the first carriage 10.

[0019] As shown in FIG. 2, the first carriage 10 has a first adjustment unit 11 and a second adjustment unit 21 capable of adjusting the position of the second carriage 30. The first adjustment unit 11 is disposed at the lower part of the first carriage 10, and the second adjustment unit 21 is disposed at the upper part thereof. The second carriage 30 has a first contact portion 31 capable of contacting the first adjustment unit 11 and a second contact portion 32 capable of contacting the second adjustment unit 21. The first contact portion 31 and the second contact portion 32 have a shape protruding toward the first carriage 10 at the rear.

[0020] 3. First adjustment unit First, the first adjustment unit 11 will be described with reference to FIGS. 2 and 3. The first adjustment unit 11 is a position adjustment mechanism capable of adjusting the position of the second carriage 30 in a direction changing the distance PG, which is the distance between the head 33 and the platen P, as described below. The first adjustment unit 11 includes a first shaft 13 that is a rotation axis and a receiving component 14 that is inserted through the first shaft 13 and receives the second carriage 30. The first shaft 13 can rotate freely while the receiving component 14 is inserted therethrough.

[0021] The first shaft 13 extends in the left - right direction. The first shaft 13 may be attached so as to be parallel to the carriage shaft 24. The receiving component 14 has a square shape when viewed from the axial direction of the first shaft 13. The receiving component 14 is provided with a flat surface 14a on the upper side. The flat surface 14a is a surface parallel to the platen P. Furthermore, the receiving component 14 may have shapes other than a square or other quadrilateral when viewed from the axial direction of the first shaft 13, such as a triangle or pentagon. In other words, the receiving component 14 may have multiple flat surfaces similar to the flat surface 14a. All of these multiple flat surfaces are configured to be at equal distances from the first shaft 13. When the distances of the multiple flat surfaces from the first shaft 13 are equal, multiple angles can be selected for the receiving component 14 that passes through the first shaft 13, making assembly easier. The receiving component 14 can also be considered as a cam having multiple flat surfaces. The receiving component 14 may also have a shape in which each corner of the polygon viewed from the axial direction of the first shaft 13 is chamfered.

[0022] The first adjustment section 11 includes a plate-shaped spacer 15 having flat surfaces on its upper and lower sides. The lower surface of the spacer 15 abuts against the flat surface 14a of the receiving component 14, and the upper surface abuts against the first contact portion 31 of the second carriage 30. By interposing the spacer 15, the receiving component 14 can stably support and move the first contact portion 31. Furthermore, if the area below the first contact portion 31 that abuts the receiving component 14 is a flat surface, it is not necessary to interpose the spacer 15. In this case, the flat surface 14a of the receiving component 14 and the first contact portion 31 of the second carriage 30 can stably come into direct contact.

[0023] If the upper surface of the receiving part 14 that contacts the lower surface of the first contact portion 31 is a curved surface rather than a flat surface like the flat surface 14a, stable contact cannot be achieved. The receiving part 14 is prone to rotating and tilting around the first axis 13. In this case, after the position of the second carriage 30 is adjusted by the first adjustment unit 11, there is a risk that the position may shift due to the rotation of the receiving part 14 or other reasons.

[0024] According to the above-described embodiment, the flat surface 14a of the receiving component 14 and the first contact portion 31 of the second carriage 30 come into contact with each other as flat surfaces, either directly or with a spacer 15 in between, thus enabling stable contact. In the following description, it will be assumed that the flat surface 14a and the first contact portion 31 are in direct contact. That is, the receiving component 14 has a flat surface 14a parallel to the platen P, and the second carriage 30 can be supported by the flat surface 14a. Furthermore, it is preferable that the second carriage 30 be equipped with an adjustment mechanism or the like so that the contact surface of the first contact portion 31 always remains parallel to the platen P.

[0025] The first adjustment unit 11 has a first eccentric cam 12 that supports the first shaft 13 while eccentrically rotating it. When the first eccentric cam 12 rotates, the first shaft 13 also moves vertically in an arc. At this time, the receiving part 14 inserted through the first shaft 13 also moves vertically along with the movement of the first shaft 13. The first eccentric cam 12 is fixed to the first lever 16 shown in Figure 3. The first eccentric cam 12 can be rotated by the user's operation of the first lever 16.

[0026] Incidentally, a third spring 44 is attached between the first carriage 10 and the second carriage 30 in an oblique direction, including the vertical direction. The third spring 44 is a so-called tension coil spring. The third spring 44 exerts a force on the first carriage 10 and the second carriage 30, pulling them in a direction including the vertical direction. As described above, the flat surface 14a of the receiving component 14 and the first contact portion 31 of the second carriage 30 are in contact with each other. The pulling force from the third spring 44 acts in the vertical direction, which is the direction in which the flat surface 14a and the first contact portion 31 come into contact. The flat surface 14a and the first contact portion 31 can come into contact more strongly.

[0027] The third spring 44 makes the contact between the flat surface 14a and the first contact portion 31 more stable. Even if the receiving component 14 moves vertically as the first shaft 13 moves, changes in these contact states are suppressed. In this way, when the first shaft 13 moves, the receiving part 14 is prevented from tilting or changing its posture, and can move vertically while maintaining the same posture. The flat surface 14a and the first contact part 31 are maintained in a state where their flat surfaces are in contact with each other, and changes in this contact state are prevented. In other words, the receiving component 14 is configured so as not to change its orientation due to the rotation of the first axis 13. As a result, changes in the distance PG are suppressed, as will be described later.

[0028] Next, the adjustment of the distance PG by the first adjustment unit 11 will be explained. In the first adjustment unit 11, when the user operates the first lever 16 shown in Figure 3 to raise it, the first eccentric cam 12 rotates clockwise as shown in Figure 2, and the first shaft 13 moves upward in an arc. At this time, the receiving part 14 inserted through the first shaft 13 also moves upward along with the movement of the first shaft 13. The flat surface 14a of the receiving component 14 maintains contact with the first contact portion 31 of the second carriage 30, and pushes the first contact portion 31 upward, thereby moving the second carriage 30 upward.

[0029] In the examples shown in Figures 2 and 3, the receiving part 14 of the first adjustment unit 11 and the first contact part 31 of the second carriage 30 are raised over a distance L1. In this way, the first adjustment unit 11 can raise the second carriage 30 over a distance L1 by raising the first lever 16.

[0030] As described above, the second carriage 30 supports the head 33. As the second carriage 30 rises, the head 33 also rises over a distance L1. As a result, the distance PG, which is the distance between the head 33 and the platen P, also becomes relatively longer by distance L1. In this way, the first adjustment unit 11 can be adjusted to increase the distance PG.

[0031] On the other hand, in the first adjustment unit 11, when the user operates the first lever 16 shown in Figure 3 to lower it, the first eccentric cam 12 rotates counterclockwise, as shown in Figure 2, and the first shaft 13 moves downward in an arc. At this time, the receiving part 14 inserted through the first shaft 13 also moves downward along with the movement of the first shaft 13. The flat surface 14a of the receiving component 14 can move the first contact portion 31 of the second carriage 30 downward while maintaining contact with the first contact portion 31 of the second carriage 30, thereby moving the second carriage 30 downward.

[0032] The receiving part 14 of the first adjustment unit 11 and the first contact part 31 of the second carriage 30 are lowered over a distance L1. In this way, the first adjustment unit 11 can lower the second carriage 30 over a distance L1 by lowering the first lever 16. As the second carriage 30 descends, the head 33 also descends over a distance of L1.

[0033] As a result, the distance PG, which is the distance between the head 33 and the platen P, also becomes relatively shorter by distance L1. In this way, the first adjustment unit 11 can be adjusted to shorten the distance PG. In other words, the first adjustment unit 11 is provided on the first carriage 10 and can adjust the distance between it and the second carriage 30 by, for example, a distance L1. As a result, the first adjustment unit 11 can adjust the position of the second carriage 30 in the vertical direction, which is the direction in which the distance PG changes.

[0034] As described above, the flat surface 14a of the receiving part 14 of the first adjustment unit 11 and the first contact portion 31 of the second carriage 30 equipped with the head 33 are in stable contact with each other due to their flat surfaces. Even after the first adjustment unit 11 is adjusted, changes in these contact conditions are suppressed. As a result, even after the distance PG is adjusted by the first adjustment unit 11, variations in the distance PG are suppressed. The first eccentric cam 12 may also be configured to be screw-fastened. After adjusting the distance PG by operating the first lever 16 of the first adjustment unit 11, the user can screw the first eccentric cam 12 in place to fix it in place.

[0035] Next, the adjustment of the left-right tilt of the head 33 by the first adjustment unit 11 will be described. As shown in Figure 3, two first adjustment units 11 are provided and are arranged symmetrically on the left and right sides of the first carriage 10. For example, if the head 33 is tilted so that it is lowered to the right and raised to the left, the user can raise the right side of the second carriage 30 using the first adjustment unit 11 on the right. Alternatively, the user can lower the left side of the second carriage 30 using the first adjustment unit 11 on the left. Or, the user can do both of these.

[0036] As a result, the second carriage 30 is modified so that the right side is raised and the left side is lowered, and its tilt is adjusted. At the same time, the tilt of the head 33 supported by the second carriage 30 is also adjusted in the same manner. Furthermore, even if the head 33 is tilted to the opposite side to the one described above, the tilt can be adjusted by reversing the upward and downward movements of the left and right first adjustment units 11. After adjusting the distance PG and the tilt of the head 33 using the first adjustment unit 11, the distance PG can be adjusted by changing the distance from the first shaft 13 to the flat surface 14a. In this case, the receiving part 14 can be replaced with one that has a different distance from the first shaft 13 to the flat surface 14a. After replacing the receiving part 14 with one that has a different distance from the first shaft 13 to the flat surface 14a, the distance PG and the tilt of the head 33 can also be adjusted using the first adjustment unit 11. If each of the multiple flat surfaces of the receiving part 14 is at a different distance from the first shaft 13, the distance PG can also be adjusted by changing the angle of the receiving part 14 that is inserted into the first shaft 13.

[0037] 4.Second adjustment section Next, the second adjustment unit 21 will be described with reference to Figure 2. The second adjustment section 21 includes a second shaft 23 that passes through the second contact portion 32 of the second carriage 30. The second shaft 23 extends in the left-right direction. The second shaft 23 may be mounted parallel to the carriage shaft 24. The second shaft 23 can rotate freely while passing through the second contact portion 32. The second adjustment unit 21 has a second eccentric cam 22 that supports the second shaft 23 while eccentrically shifting it. When the second eccentric cam 22 rotates, the second shaft 23 moves while tracing an arc L2. For illustrative purposes, in Figure 2, the arc L2 is drawn outside the second shaft 23.

[0038] As a result, the second contact portion 32 of the second carriage 30, which is inserted through the second shaft 23, can also move along the arc L2. That is, the moving second contact portion 32 allows the entire second carriage 30 to rotate around the position where it contacts the first stopper 40 or the second stopper 41 as a pivot point. The second adjustment unit 21 allows the upper and lower distances between the first carriage 10 and the second carriage 30 to be changed by rotating the second carriage 30, thereby adjusting the front-to-back tilt of the second carriage 30. By adjusting the front-to-back tilt of the second carriage 30, the front-to-back tilt of the head 33 can be adjusted.

[0039] For example, if the head 33 is tilted so that the front is raised and the rear is lowered, in the state shown in Figure 2, the user rotates the second eccentric cam 22 of the second adjustment unit 21 clockwise. As the second shaft 23 rotates clockwise along the arc L2, the second contact unit 32 moves so as to be pushed forward, and the second carriage 30 and the head 33 tilt forward. As a result, the head 33 is adjusted so that the front is lower and the rear is raised. On the other hand, if the head 33 is tilted so that the front is lower and the rear is higher, in the state shown in Figure 2, the user can rotate the second eccentric cam 22 of the second adjustment unit 21 counterclockwise, in the opposite direction to what was described above. The second shaft 23 rotates counterclockwise along the arc L2, causing the second contact part 32 to move as if being pulled backward, and the second carriage 30 and head 33 to tilt backward. As a result, the head 33 is adjusted so that the front is higher and the rear is lower.

[0040] The second adjustment unit 21 may also be equipped with a lever similar to the first lever 16 of the first adjustment unit 11, and may be configured to allow the second eccentric cam 22 to be screwed in. After adjusting the front-to-back tilt of the head 33 by operating the lever of the second adjustment unit 21, the user can screw in and fix the second eccentric cam 22.

[0041] As described above, the printing apparatus 1 comprises a platen P that supports a medium M, a head 33 that discharges liquid onto the medium M supported by the platen P, a second carriage 30 that supports the head 33, and a first carriage 10 that supports the second carriage 30. Furthermore, the printing apparatus 1 includes a first adjustment unit 11 provided on the first carriage 10, which can adjust the position of the second carriage 30 in a direction that changes the platen gap, which is the distance between the platen P and the head 33, by adjusting the distance between the second carriage 30 and the first carriage 10. The first adjustment unit 11 consists of a first shaft 13 and a receiving part 14 that is inserted into the first shaft 13 and receives the second carriage 30, and the receiving part 14 can not change its position due to the rotation of the first shaft 13.

[0042] In this way, the flat surface 14a of the receiving part 14 of the first adjustment unit 11 and the first contact portion 31 of the second carriage 30 equipped with the head 33 are in stable contact. Even after the first adjustment unit 11 is adjusted, changes in these contact states are suppressed. As a result, even after the distance PG is adjusted by the first adjustment unit 11, changes in the distance PG are suppressed. This is effective when the type of media M used for printing is limited and printing is performed with the thickness of the media M not changing much.

[0043] Although embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may be modified, substituted, deleted, etc., as long as it does not depart from the spirit of this invention. [Explanation of symbols]

[0044] 1…Printing device, 2…Printing unit, 10…First carriage, 11…First adjustment unit, 12…First eccentric cam, 13…First shaft, 14…Receiving part, 14a…Flat surface, 21…Second adjustment unit, 22…Second eccentric cam, 23…Second shaft, 24…Carriage shaft, 30…Second carriage, 31…First contact part, 32…Second contact part, 33…Head, 33a…Nozzle surface, 40…First stopper, 41…Second stopper, 42…First spring, 43…Second spring, 44…Third spring, F…Conveying direction, L1…Distance, L2…Arc, M…Media, P…Platen, PG…Distance.

Claims

1. The platen that supports the medium, A head for dispensing liquid into the medium supported by the platen, A subcarriage supporting the head, The main carriage supporting the aforementioned subcarriage, A position adjustment mechanism is provided on the main carriage, which can adjust the position of the sub-carriage in a direction that changes the distance between the platen and the head by adjusting the distance between the sub-carriage and the main carriage, Equipped with, The position adjustment mechanism consists of a rotating shaft and a receiving component that is inserted through the rotating shaft and receives the subcarriage. The printing apparatus is characterized in that the receiving component does not change its orientation due to the rotation of the rotating shaft.

2. The printing apparatus according to claim 1, characterized in that the receiving component has a flat surface parallel to the platen and receives the subcarriage with the flat surface.

3. The receiving component has a plurality of the flat surfaces, The printing apparatus according to claim 2, characterized in that all of the multiple flat surfaces are at the same distance from the axis of rotation.

4. The printing apparatus according to claim 3, characterized in that the receiving component is square when viewed from the axial direction of the rotating shaft.

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