Recording device

Abstract

To provide a recording device having a mechanism capable of suppressing vibrations of a carriage.SOLUTION: A recording device includes conveying means for conveying sheet in a conveyance direction, a recording head which discharges liquid in opposition to the sheet conveyed by the conveying means and records an image, a carriage which mounts the recording head thereon and is moved in a scanning direction intersecting the conveying direction and a guide part which supports the carriage and guides movement of the carriage in the scanning direction. Therein, the guide part supports the carriage by means of a guide face which is inclined to the upper side as proceeding to the downstream side in the conveyance direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus that records an image by ejecting ink from a recording head onto a sheet. [Background technology]

[0002] An inkjet recording device includes a recording head that ejects ink onto a sheet, a transport unit that transports the sheet in a transport direction, and a carriage that moves the recording head in a scanning direction that intersects with the transport direction. The carriage is guided by a guide unit and can move back and forth in the scanning direction. Patent Document 1 describes a recording device that can change the distance between the recording head and the sheet. In such a recording device, the distance between the sheet and the recording head can change due to vibration when the carriage moves. Therefore, carriage vibration is suppressed by pressing the carriage against the guide unit using a biasing means such as a spring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-23501 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration using such a biasing means, the pressing force of the biasing means is added to the carriage's own weight, resulting in a large sliding load between the guide section and the carriage. In this case, a motor with a large driving force is used to move the carriage. Therefore, further ingenuity is required for the mechanism to suppress carriage vibration. Therefore, an object of the present invention is to provide a recording device having a mechanism that can suppress carriage vibration without using a biasing means. [Means for solving the problem]

[0005] The recording apparatus of the present invention is a recording apparatus comprising: a conveying means for conveying a sheet in a conveying direction; a recording head that faces the sheet conveyed by the conveying means and ejects liquid to record an image; a carriage that carries the recording head and moves in a scanning direction that intersects with the conveying direction; and a guide unit that supports the carriage and guides the movement of the carriage in the scanning direction, and the guide unit supports the carriage with a guide surface that slopes upward as it proceeds downstream in the conveying direction. The carriage has a sliding member that contacts the guide surface, and a distance control member that contacts the sliding member and moves relative to the sliding member in the scanning direction to change the height of the recording head. It is characterized by: [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a recording apparatus having a mechanism capable of suppressing vibration of the carriage. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a main part of an inkjet recording apparatus. [Figure 2] FIG. 2 is a diagram showing the configuration of a carriage and a frame. [Figure 3] FIG. 2 is a cross-sectional view of the carriage and the frame. [Figure 4] FIG. 2 is a cross-sectional view of the lower part of the carriage and frame. [Figure 5] FIG. 2 is a cross-sectional view of the carriage and the frame at the top. [Figure 6] 10A and 10B are diagrams illustrating the structure of a distance control member. [Figure 7] FIG. 2 is a diagram showing the structure of a sliding member. [Figure 8] 5A and 5B are schematic diagrams showing forces acting on a sliding member. [Figure 9] 10A and 10B are diagrams illustrating the positional relationship of support surfaces of sliding members. [Figure 10] FIG. 4 is a cross-sectional view showing a convex surface of a sliding member. [Figure 11] FIG. 2 is a front view of the carriage and frame. [Figure 12] FIG. 10 is a cross-sectional view of a carriage and a frame in a second embodiment. [Figure 13] FIG. 11 is a cross-sectional view of a distance control member and a sliding member in a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the present invention, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the present invention. Note that the same components will be described with the same reference numerals. Furthermore, the relative arrangements, shapes, etc. of the components described in the embodiments are merely examples, and are not intended to limit the scope of the present invention to only those.

[0009] <Inkjet recording device> Figure 1 shows a perspective view of the main parts of an inkjet recording device. The inkjet recording device (hereinafter referred to as recording device 1) comprises a feeding mechanism 2, a conveying section 3, a discharge section 4, and a carriage unit 5. A sheet, which is a recording medium, placed on a tray 42 on the rear side of recording device 1 is fed to conveying section 3 by feeding mechanism 2. The sheet fed from feeding mechanism 2 is then conveyed in the conveying direction (Y direction) by conveying section 3 to a platen 8.

[0010] The recording head 6 has an ejection surface for ejecting ink, which is a liquid, and the ejection surface faces the platen 8 at a predetermined distance. The recording head 6 ejects liquid onto a sheet supported by the platen 8 while moving back and forth in a scanning direction (X direction) relative to the sheet transport direction. An image is recorded on the sheet by alternately repeating the sheet transport operation by the transport unit 3 and the ink ejection operation by the recording head 6. The sheet with the image recorded is discharged to the front of the recording device by the discharge unit 4.

[0011] <Carriage unit> The carriage unit will be described using Figures 2 to 5. Figure 2 shows the configuration of the carriage unit and frame, with (a) being a perspective view of the carriage unit and (b) being a cross-sectional view showing the carriage unit and frame. Figure 3 is a cross-sectional view of the carriage and frame, with (a) being a cross-sectional view of the carriage unit and frame taken along line AA in Figure 2 and (b) being a cross-sectional view of the frame taken along line BB in Figure 2. Figure 4 is a cross-sectional view of the lower part of the carriage unit and frame. Figure 5 is a cross-sectional view of the upper part of the carriage unit and frame.

[0012] The carriage unit 5 includes a carriage 7 and a recording head 6. The carriage 7 is mounted with the recording head 6. The carriage unit 5 receives driving force from a belt 33 and can move back and forth in the scanning direction, which is the width direction of the sheet. The belt 33 is looped around pulleys on both ends of a frame 13 and is driven back and forth by a motor 14. The carriage 7 has a distance control member 9 and a sliding member 10 in an area surrounded by a downstream regulating surface 38 and an inner surface 41 on the downstream side in the conveying direction, and an upstream regulating surface 39 on the upstream side (FIG. 8). The sliding member 10 supports the carriage 7 and slides against a guide portion 15 of the frame 13. The distance control member 9 is disposed between the inner surface 41 of the carriage 7 and the sliding member 10 in the vertical direction (Z direction). The distance control member 9 moves in the scanning direction relative to the carriage 7 to change the vertical distance between the recording head 6 and the sheet.

[0013] The carriage 7 is supported by the guide unit 15 via the distance control member 9 and the sliding member 10 at the inner surface 41. Therefore, the sliding member 10 bears the weight of the carriage 7. The upstream end of the guide unit 15 in the conveying direction is fastened to the fastening surface of the frame 13 with screws. Note that the guide unit 15 may also be attached to the frame 13 by other methods, such as adhesive bonding or welding. Meanwhile, the downstream end 16 of the guide unit 15 in the conveying direction supports the carriage 7 with a guide surface 25. The guide surface 25 of the guide unit 15 slopes upward at a predetermined angle as it advances downstream in the conveying direction. The lower support surface 17 of the sliding member 10 similarly slopes upward at a predetermined angle as it advances downstream in the conveying direction and abuts against the guide surface 25. Therefore, the guide unit 15 receives a downward pressing force (P1) toward the sheet and a pressing force P2 toward the conveying direction (Figure 2). In this example, the predetermined angle is 50 degrees, but any angle that can support the carriage 15 is acceptable. That is, it can be from 0 to 89 degrees. However, the inclination of the guide surface 25 is preferably in the range of 40 to 60 degrees.

[0014] The frame 13 has an upper sliding portion 11 above and a lower sliding portion 12 below in the vertical direction. An upper abutting portion 18 of the carriage 7 abuts against an upper sliding surface 30 of the upper sliding portion 11. Meanwhile, a lower abutting portion 19 of the carriage 7 abuts against a lower sliding surface 31 of the lower sliding portion 12. The upper sliding surface 30 faces upstream in the transport direction. The lower sliding surface 31 faces downstream in the transport direction. A guide surface 25 is located between the lower sliding surface 31 and the fastening surface of the frame 13 in the transport direction. The upper sliding surface 30 and the lower sliding surface 31 are parallel to the scanning direction. Therefore, when changing the gap between the recording head 6 and the platen 8, the carriage 7 moves up and down in the vertical direction relative to the platen 8 with the upper abutting portion 18 abutting against the upper sliding surface 30 and the lower abutting portion 19 abutting against the lower sliding surface 30. Because the lower sliding surface 30 and the upper sliding surface 31 are perpendicular to the sheet, there is no difference in height of the ejection surface relative to the platen 8 between the upstream and downstream sides in the transport direction of the recording head 6. This makes it possible to stabilize image quality even for sheets of various thicknesses. The frame 13 is formed from a single plate by bending it along a line parallel to the scanning direction.

[0015] Here, the force that the frame 13 receives from the carriage 7 will be described with reference to FIG. 2(b). The center of gravity of the carriage 7 is on the recording head 6 side in the transport direction. Therefore, the upper sliding portion 11 is pressed by the upper contact portion 18 of the carriage 7 with a pressing force (P4) toward the downstream side in the transport direction. Meanwhile, the lower sliding portion 12 is pressed by the lower contact portion 19 of the carriage 7 with a pressing force (P3) toward the upstream side in the transport direction (opposite the transport direction). As a result, the frame 13 restricts the rotation of the carriage 7 in direction D and determines the position of the carriage 7 in the transport direction. Furthermore, the lower support surface 17 of the sliding member 10 presses the guide surface 25 of the guide portion 15 with a pressing force P2 toward the downstream side in the transport direction. Meanwhile, the lower contact portion 19 on the downstream side of the lower support surface 17 in the transport direction presses the lower sliding portion 12 with a pressing force P3 toward the upstream side in the transport direction (opposite the transport direction). That is, the guide surface 25 of the guide portion 15 is pressed by the carriage 7 with a pressing force toward the downstream side in the conveying direction. On the other hand, the lower sliding portion 12 is pressed by a pressing force from the carriage 7 toward the upstream side in the conveying direction. The lower sliding portion 12 and the guide portion 15 generate opposing resistance forces. As a result, the carriage 7 is restricted from moving in the conveying direction and is stably supported by the frame 13. This mechanism makes it possible to suppress vibrations that occur during scanning of the support carriage 7.

[0016] In addition, in a configuration in which the carriage 7 is supported by a flat frame 13 rather than by an inclined guide portion 15, the carriage needs to be pressed by a spring. In this embodiment, the inclination of the guide surface 25 converts the weight of the carriage 7 into a pressing force (P2) toward the downstream side in the conveying direction, making it possible to eliminate the need for a spring. As a result, the pressing force with which the carriage 7 presses the guide portion 15 is mainly a force based on the weight of the carriage 7. This reduces the sliding load acting between the guide portion 15 and the lower support surface 17.

[0017] <Gap control member and sliding member> The distance control member 9 and the sliding member 10 will be explained using Figures 6 to 11. Figure 6 shows the structure of the distance control member 9, and Figure 7 shows the structure of the sliding member 10. Figure 8 is a schematic diagram of the forces that the sliding member receives. Figure 9 is a diagram showing the positional relationship between the lower support surface 17 and the upper support surface 20 of the sliding member 10. Figure 10 is a cross-sectional view showing the relationship between the convex surface of the sliding member and the regulating surface of the carriage. Figure 11 is a front view of the carriage as seen from the front side of the recording device.

[0018] The distance control member 9 is sandwiched between the inner surface 41 of the carriage 7 and the sliding member 10 in the vertical direction (Z direction). As shown in FIG. 6, a cam surface 24 consisting of a flat surface parallel to the sheet and a sloped surface inclined relative to the sheet is formed on the sliding member 10 side of the distance control member 9. The cam surfaces 24 are located at two positions spaced apart in the scanning direction (H direction). As shown in FIG. 7, the sliding member 10 has lower support surfaces (17a, 17b) located at positions spaced apart in the scanning direction (H direction) of the sliding member 10. The two cam surfaces (24a, 24b) of the distance control member 9 respectively abut against two upper support surfaces (20a, 20b) spaced apart in the scanning direction (H direction) of the sliding member 10. The lower support surface 17 of the sliding member 10 is supported by the guide surface 25 of the guide unit 15. As a result, the carriage 7 is supported by the guide unit 15. The upper support surface 20 and the lower support surface 17 are positioned so that they do not overlap in the transport direction. Therefore, the carriage 7 rotates in one direction around the scanning axis. The sliding member 10 has a regulating portion 40 that regulates the movement of the carriage 7 in the transport direction or the vertical direction. In the transport direction, the guide portion 15 is sandwiched between the regulating portion 40 and the sliding member 10. In other words, the regulating portion 40 is located on the opposite side of the guide surface 25 from the lower support surface 17. The regulating portion 40 is positioned so that the position of its lower end is not lower than the position of the lower end of the guide portion 15.

[0019] The distance control member 9 is slidable in the scanning direction relative to the carriage 7. The cam surface 24 of the distance control member 9 slides against the upper support surface 20, changing the relative height of the distance control member 9 with respect to the sliding member 10. This changes the distance between the carriage 7 and the sliding member 10. In other words, the distance between the recording head 6 mounted on the carriage 7 and the platen 8 can be changed. By sliding the distance control member 9 relative to the carriage 7 in this way, the distance between the platen 8 and the recording head 6 can be changed depending on the thickness or type of the sheet.

[0020] The sliding member 10 has a downstream convex surface 21 on the downstream side in the conveying direction and an upstream convex surface 22 on the upstream side. Meanwhile, the carriage 7 has a downstream regulating surface 38 on the downstream side and an upstream regulating surface 39 on the upstream side that regulate the movement of the convex surface of the sliding member 10 in the conveying direction. The downstream regulating surface 38 and the upstream regulating surface 39 face each other on the inside of the carriage 7. These regulating surfaces regulate the rotation of the sliding member 10 around the scanning direction axis (direction R) ( FIG. 8 ). Because the carriage 7 is supported by the guide surface 25, the forces acting on the downstream regulating surface 38 and the upstream regulating surface 39 are reduced. This reduces the rigidity of the carriage 7, leading to cost savings through thinner materials. The position of the center of gravity of the carriage 7 and the arrangement of the downstream regulating surface 38 and the upstream regulating surface 39 regulate the rotation around the scanning direction axis to a predetermined angle. Due to the configuration of the carriage unit 7 and the configuration of the frame 13, the moment around the scanning axis remains counterclockwise, so rattles caused by movement of the carriage 7 can be suppressed.

[0021] Here, the rotation of the sliding member 10 around the scanning direction axis becomes the direction R, which will be described in detail. As shown in FIG. 9 , imaginary planes parallel to the lower support surface 17 and the upper support surface 20 are defined as plane A and plane B, respectively. The projections of the lower support surface 17 and the upper support surface 20 onto plane A are defined as projection Ai and projection Aii, respectively. The projections of the lower support surface 17 and the upper support surface 20 onto plane B are defined as projection Bi and projection Bii, respectively. The lower support surface 17 and the upper support surface 20 of the sliding member 10 are arranged in positions where projection Ai is below projection Aii in the vertical direction and upstream in the transport direction so as not to overlap. The lower support surface 17 and the upper support surface 20 of the sliding member 10 are arranged in positions where projection Bi is upstream in the transport direction so as not to overlap projection Bii. In this manner, the projections of the lower support surface 17 and the upper support surface 20 are positioned so as not to overlap, and therefore the moment around the scanning direction axis generated by the forces received by the sliding member 10 from the lower support surface 17 and the upper support surface 20 is determined to be counterclockwise (direction R). Note that the support surfaces may be arranged so that the projection Ai is downstream of the projection Aii in the transport direction.

[0022] The upper support surface 20 of the sliding member 10 receives a downward force F1 in the direction of gravity due to the weight of the carriage 7. Therefore, the lower support surface 17 receives a resultant force F2, which is a result of the drag force due to the weight of the carriage 7 and the drag force generated by the moment (direction M), in a direction perpendicular to the lower support surface 17. Incidentally, the carriage 7 is connected to a timing belt 33, and moves in a scanning direction 34 as the timing belt 33 rotates. While the carriage 7 is scanning, a moment (direction M) about the transport direction axis is generated in the carriage 7 due to inertia due to the driving force generated by the rotation of the timing belt. At this time, the forces received by the lower support surface 17a and the lower support surface 17b are different. However, the moment (direction M) about the transport direction axis is less likely to affect the moment (direction R) about the scanning direction axis. Therefore, even if a moment (direction M) is generated around the transport direction axis on the carriage 7, no large change occurs that would cause the moment (direction R) around the scanning direction axis on the carriage 7 to be in the opposite direction. As a result, the carriage 7 can maintain its posture around the scanning direction axis of the sliding member 10.

[0023] The above-described mechanism reduces the energy required for carriage scanning, allowing the use of a motor with a smaller driving force. As a result, the size of the recording device can be reduced. Furthermore, the spring used to press the guide unit and carriage can be eliminated, reducing the number of parts and assembly steps. Also, carriage vibration can be suppressed without using a spring to press the carriage 7 against the guide unit 15. As a result, the carriage posture is stabilized, carriage vibration is suppressed, and image quality from the recording head is improved. In this way, a recording device having a mechanism that can suppress carriage vibration can be provided.

[0024] [Second embodiment] A second embodiment of the present invention will be described below with reference to the drawings. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so only the distinctive features will be described below.

[0025] A cross-sectional view of a carriage unit in the second embodiment is shown in Figure 12. The guide section 15 in the first embodiment is integrated with the frame 13. The guide surface 25 of the frame 13 is inclined upward with respect to the conveyance direction. A lower sliding surface 31 is provided below the end of the guide surface 25. An upper sliding surface 30 is provided at the opposite end of the frame 13. The frame 13 is formed from a single plate by bending it along a line parallel to the scanning direction of the carriage 7.

[0026] The center of gravity of the carriage 7 is located on the recording head 6 side in the transport direction. Therefore, the upper sliding surface 30 is pressed by the carriage 7 with a pressing force toward the downstream side in the transport direction. On the other hand, the lower sliding surface 31 is pressed by the carriage 7 with a pressing force toward the upstream side in the transport direction. The guide surface 25 on which the lower support surface 17 of the sliding member 10 slides is inclined upward as it advances downstream in the transport direction. Therefore, the inclination of the guide surface 25 converts the carriage 7's own weight into a pressing force toward the downstream side in the transport direction. As a result, the pressing force from the spring can be reduced, and the sliding load between the carriage 7 and the frame 13 can be reduced. In addition, the vertical surfaces on which the carriage 7 slides (the lower sliding surface 30 and the upper sliding surface 31) make it possible to change the distance between the carriage 7 and the platen 8 while keeping the recording head 6 horizontal. Because the configuration of the carriage unit 7 and the frame 13 ensures that the moment around the scanning axis remains constant in the counterclockwise direction, rattle caused by movement of the carriage 7 can be suppressed. In this way, it is possible to provide a recording apparatus having a mechanism that can suppress carriage vibration. Furthermore, since there is no need to separate the guide portion, the number of parts can be reduced.

[0027] [Third embodiment] Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so only the distinctive features will be described below.

[0028] FIG. 13 shows a cross-sectional view of the distance control member and sliding member in the third embodiment. One end of the guide portion 15 is connected to the fastening surface of the frame 13, and the other end extends downstream parallel to the transport direction. A guide surface for supporting the carriage 7 is provided at the other end of the guide portion 15. The lower support surface 23 of the sliding member 10 is parallel to the transport direction and abuts against the guide surface of the guide portion 15. The lower support surface 23 and the upper support surface 20 of the sliding member 10 are positioned so that projection Ai does not overlap with projection Aii upstream in the transport direction. As a result, the moment around the scanning direction axis of the carriage 7 is determined counterclockwise. Even if a moment around the transport direction axis occurs on the carriage 7, no significant change occurs that would reverse the moment around the scanning direction axis for the carriage 7. Therefore, the carriage 7 can maintain its position around the scanning direction axis of the sliding member 10. In this way, a recording device having a mechanism for suppressing carriage vibration can be provided. [Explanation of symbols]

[0029] 3. Conveyor 6 recording head 7 Carriage 15 Guide section

Claims

1. a conveying means for conveying the sheet in a conveying direction; a recording head that faces the sheet conveyed by the conveying means and discharges liquid to record an image; a carriage on which the recording head is mounted and which moves in a scanning direction intersecting the transport direction; a guide portion that supports the carriage and guides the movement of the carriage in the scanning direction; A recording device comprising: the guide portion supports the carriage by a guide surface that slopes upward as it advances downstream in the conveying direction, a distance control member that contacts the sliding member and moves in the scanning direction relative to the sliding member to change the height of the recording head;

2. 2. The recording device according to claim 1, wherein the sliding member has a first convex surface that abuts against a first regulating surface on the upstream side of the carriage in the transport direction, and a second convex surface that abuts against a second regulating surface on the downstream side of the carriage in the transport direction.

3. 3. The recording apparatus according to claim 2, wherein the first and second regulating surfaces face each other on the inside of a carriage.

4. the sliding member has a first support surface that supports the distance control member and a second support surface that is supported by the guide surface, 4. The recording apparatus according to claim 1, wherein the first support surface and the second support surface are positioned so as not to overlap with each other in the transport direction.

5. 5. The recording apparatus according to claim 1, wherein the sliding member has a restricting portion that restricts movement of the carriage in the transport direction or in a vertical direction.

6. 6. The recording apparatus according to claim 5, wherein the guide portion is located between the regulating portion and the sliding member in the transport direction.

7. 7. The recording apparatus according to claim 5, wherein the position of the lower end of the regulating portion is not lower than the position of the lower end of the guide portion.

8. a frame to which the guide portion is fastened, 8. A recording device according to claim 1, wherein the frame has a first sliding portion that abuts against a first abutment portion of the carriage, and a second sliding portion that abuts against a second abutment portion of the carriage.

9. a conveying means for conveying the sheet in a conveying direction; a recording head that faces the sheet conveyed by the conveying means and discharges liquid to record an image; a carriage on which the recording head is mounted and which moves in a scanning direction intersecting the transport direction; a guide portion that supports the carriage and guides the movement of the carriage in the scanning direction; A recording device comprising: a frame to which the guide portion is coupled, the guide portion supports the carriage by a guide surface that slopes upward as it advances downstream in the conveying direction, The recording apparatus according to claim 1, wherein the frame has a first sliding portion that comes into contact with a first contact portion of the carriage, and a second sliding portion that comes into contact with a second contact portion of the carriage.

10. The carriage includes a sliding member that abuts against the guide surface, 10. The recording apparatus according to claim 9, wherein the sliding member has a restricting portion that restricts movement of the carriage in the transport direction or in a vertical direction.

Images