Conveying device and liquid ejecting device

Abstract

To easily and accurately mount a position detection part.SOLUTION: A conveying device 20 includes a conveying roller 17 that conveys to-be-conveyed objects, a pair of roller support members 21A, 21B that support both ends of the conveying roller 17 in the axial direction, a position detection part 30 that detects positions of to-be-conveyed objects, a detection-part support member 22 that supports the position detection part 30, the pair of roller support members 21A, 21B has an insertion hole 25 for positioning the detection-part support member 22 in a direction intersecting with the insertion direction, into which the detection-part support member 22 is inserted, the detection-part support member 22 has position determination parts 221, 222 that determine the insertion direction C for at least one of the pair of roller support members 21A, 21B, the direction opposite to the direction C, and rotation direction centered on the axis of insertion direction C.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a transport device and a liquid ejection device. [Background technology]

[0002] 2. Description of the Related Art As a liquid ejection device that ejects liquid, an inkjet image forming device that ejects ink onto a sheet such as paper to form an image is known.

[0003] In an inkjet image forming apparatus, if a sheet is misaligned when conveyed by a conveyance roller or the like, the position of the ink that lands on the sheet may also be misaligned, which may result in a decrease in image quality. Therefore, some such image forming apparatuses are provided with a position detection unit such as an optical sensor that detects the position (misalignment) of the sheet in order to improve the misalignment of the ink relative to the sheet (see, for example, Patent Document 1: JP 2018-130956 A). Summary of the Invention [Problem to be solved by the invention]

[0004] The position detection unit described above needs to be mounted accurately at a predetermined mounting position so that it can accurately detect the seat position. Generally, methods for improving the mounting accuracy of the position detection unit include improving the dimensional accuracy of the parts involved in the mounting or adjusting the position after mounting. However, there are problems such as increasing the dimensional accuracy of the parts leading to increased costs, and adjusting the position after mounting leading to increased installation time. Therefore, there is a need for a solution that allows the position detection unit to be mounted easily and accurately. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a conveying device, comprising: a conveying roller for conveying an object to be conveyed; a pair of roller support members for supporting both axial ends of the conveying roller; a position detection unit for detecting the position of the object to be conveyed; and a detection unit support member for supporting the position detection unit, wherein the pair of roller support members have insertion holes into which the detection unit support member is inserted and which position the detection unit support member in a direction intersecting with the insertion direction, and the detection unit support member has a positioning unit which positions at least one of the pair of roller support members in the insertion direction and a direction opposite to the insertion direction, and in a rotational direction about an axis in the insertion direction. a positioning unit that positions the position detection unit relative to the detection unit support member in the insertion direction, the direction opposite to the insertion direction, and the direction intersecting the insertion direction; The conveying device is characterized by having: [Effects of the Invention]

[0006] According to the present invention, the position detector can be attached easily and accurately. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the overall configuration of an inkjet image forming apparatus according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram illustrating a control system of an inkjet image forming apparatus according to an embodiment of the present invention. [Figure 3] FIG. 2 is a plan view illustrating a configuration of an image forming unit according to the present embodiment. [Figure 4] FIG. 2 is a side view illustrating the configuration of the transport device according to the present embodiment. [Figure 5] FIG. 10 is a plan view showing a state in which meandering occurs in the sheet. [Figure 6] FIG. 2 is a block diagram showing a position sensor and a control system of a head unit according to the embodiment. [Figure 7] 1 is a perspective view showing a sensor mounting structure according to an embodiment of the present invention; [Figure 8] FIG. 2 is an exploded perspective view of the sensor mounting structure according to the embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a state in which a support shaft is attached to a pair of side plates. [Figure 10]FIG. 2 is an exploded perspective view showing a state before a fixing member is attached. [Figure 11] FIG. 2 is an exploded perspective view showing a state before the sensor holder is attached to each support shaft. [Figure 12] FIG. 2 is an exploded perspective view showing a state before the position sensor is attached to the sensor holder. [Figure 13] 10A and 10B are diagrams showing an example in which a support shaft is attached from the inside of a pair of side plates. [Figure 14] 10A and 10B are diagrams showing an example in which a support shaft is attached from the inside of a pair of side plates. [Figure 15] 10A and 10B are diagrams showing an example in which a support shaft is attached from the inside of a pair of side plates. [Figure 16] 10A and 10B are diagrams showing an example in which a fitting hole for positioning a support shaft in the rotational direction is provided in a side plate. [Figure 17] 10A and 10B are diagrams showing an example in which the tip of the support shaft is positioned by abutting against a side plate. [Figure 18] FIG. 10 is a diagram showing an example in which two mounting surfaces are provided on a support shaft. [Figure 19] 1 is a diagram showing the overall configuration of an electrophotographic image forming apparatus; [Figure 20] 20 is a diagram showing the configuration of a cooling device included in the image forming apparatus shown in FIG. 19. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described below with reference to the accompanying drawings. In each drawing for explaining the present invention, components such as members and components having the same function or shape are designated by the same reference numerals as far as they can be distinguished, and descriptions thereof will be omitted once they have been described.

[0009] First, the configuration of an inkjet image forming apparatus, which is one embodiment of a liquid ejection apparatus according to the present invention, will be described with reference to Figures 1 and 2. Figure 1 is a diagram showing the overall configuration of the inkjet image forming apparatus, and Figure 2 is a diagram showing the control system of the inkjet image forming apparatus.

[0010] 1, the image forming apparatus 100 according to this embodiment includes a sheet supply unit 1 that supplies a sheet S for image formation, a conveying unit 8 that conveys the supplied sheet S, a first image forming unit 3 that forms an image on the front side of the sheet S, a second image forming unit 4 that forms an image on the back side of the sheet S, a front-back reversing unit 5 that reverses the sheet S, a first drying unit 6 and a second drying unit 7 that dry the sheet S, and a sheet collecting unit 2 that collects the sheet S on which the image has been formed. The image forming apparatus 100 according to this embodiment also includes a control unit 9 (see FIG. 2) that controls the sheet supply unit 1, the conveying unit 8, the first image forming unit 3, the second image forming unit 4, the front-back reversing unit 5, the first drying unit 6, the second drying unit 7, and the sheet collecting unit 2.

[0011] The sheet supply unit 1 has a supply roller 11 around which a long sheet S is wound in a roll shape. The supply roller 11 is configured to be rotatable in the direction of the arrow shown in Fig. 1, and the sheet S is fed out by the rotation of the supply roller 11.

[0012] The conveying section 8 includes a conveying device having a plurality of conveying rollers 17. The sheet S is stretched across each of the conveying rollers 17, and the sheet S is conveyed by the rotation of each of the conveying rollers 17. The conveying rollers may also be pipes or shafts with a circular cross section.

[0013] The first image forming unit 3 has multiple head units 12Y, 12M, 12C, and 12K that eject liquid ink onto the sheet S. Each head unit 12Y, 12M, 12C, and 12K ejects ink onto the front surface of the sheet S based on image data to be formed on the front surface of the sheet S, among the image data generated by the control unit 9, to form an image on the sheet S. Here, the ink is a liquid containing a colorant, a solvent, and crystalline resin particles dispersed in the solvent. The crystalline resin is a resin that undergoes a phase change when heated above a predetermined melting point, melting from a crystalline state into a liquid.

[0014] The first drying unit 6 has a heating drum 13 that heats the sheet S to accelerate drying of the ink on the sheet S. The heating drum 13 is a cylindrical member that rotates with the sheet S wrapped around its outer circumferential surface, and has a heat source such as a halogen heater disposed inside. The heating drum 13 is disposed below the conveyance path along which the sheet S is conveyed (on the back side of the sheet S). Therefore, when the sheet S is conveyed from the first image forming unit 3, the lower surface (back side) of the sheet S comes into contact with the outer circumferential surface of the heating drum 13, and the sheet S is conveyed while being heated by the rotating heating drum 13. This accelerates drying of the ink on the sheet S. The control unit 9 controls the rotation speed of the heating drum 13 at this time to be approximately the same as the conveyance speeds of the sheet supply unit 1, the sheet recovery unit 2, the conveyance unit 8, etc. Therefore, the sheet S is conveyed without being misaligned in the sheet conveyance direction relative to the outer circumferential surface of the heating drum 13.

[0015] The front-back reversing unit 5 is configured by a known device that reverses the positions of the front and back sides of the sheet S. When the sheet S conveyed from the first drying unit 6 passes through the front-back reversing unit 5, it is reversed and sent to the second image forming unit 4. That is, when the sheet S is conveyed with the front side facing up, the front-back reversing unit 5 reverses the sheet so that the front side faces down (the back side faces up) and conveys the sheet.

[0016] The second image forming unit 4 has basically the same configuration as the first image forming unit 3, and has multiple ejection heads 14Y, 14M, 14C, and 14K that eject ink. However, in the second image forming unit 4, an image is formed on the back side of the sheet S. That is, since the sheet S is conveyed to the second image forming unit 4 in a state in which it has been inverted by the front / back reversing unit 5, the second image forming unit 4 ejects ink onto the back side of the sheet S based on image data to be formed on the back side of the sheet S out of the image data generated by the control unit 9, thereby forming an image on the sheet S.

[0017] Like the first drying section 6, the second drying section 7 has a heating drum 15 that heats the sheet S. As shown in FIG. 1, the heating drum 15 of the second drying section 7 is disposed below the conveyance path, like the heating drum 13 of the first drying section 6, but because the sheet S being conveyed is turned over, the heating drum 15 comes into contact with the front side of the sheet S. At this time, even if an image has been formed on the front side of the sheet S, the drying of the ink has already been promoted by the first drying section 6, so the image will not be disturbed by the heating drum 15 coming into contact with the image on the front side.

[0018] The sheet collection unit 2 has a collection roller 16 that winds up and collects the sheet S. The collection roller 16 is configured to be rotatable in the direction of the arrow shown in Fig. 1, and as the collection roller 16 rotates, the sheet S is wound up in a roll and collected. The sheet collection unit 2 may also include a post-processing unit that performs post-processing such as cutting the sheet S to a predetermined length and aligning the cut sheets S.

[0019] The control unit 9 is configured by an information processing device such as a PC (Personal Computer). The control unit 9 generates image data to be formed on the front and back surfaces of the sheet S, and also controls various operations of the sheet supply unit 1, first image forming unit 3, second image forming unit 4, front / back reversing unit 5, first drying unit 6, second drying unit 7, and sheet collection unit 2. For example, the control unit 9 controls the rotation speeds of the supply roller 11, collection roller 16, and each conveyance roller 17, as well as the temperature of the heat source that heats each heating drum 13, 15.

[0020] Next, the configuration of the image forming unit according to this embodiment will be described in detail with reference to Fig. 3. As described above, the image forming unit according to this embodiment includes the first image forming unit 3 and the second image forming unit 4, but since these units have basically the same configuration, only the configuration of the first image forming unit 3 will be described and the configuration of the second image forming unit 4 will not be described.

[0021] 3, in the first image forming section 3 according to this embodiment, four head units 12K, 12C, 12M, and 12Y that eject black (K), cyan (C), magenta (M), and yellow (Y) inks are arranged in this order from the upstream side in the sheet conveying direction A in which the sheet S is conveyed. Note that the order of the head units 12K, 12C, 12M, and 12Y may be an order other than that shown in the figure. Furthermore, the ink colors used may be colors other than yellow, magenta, cyan, and black.

[0022] Each of the head units 12K, 12C, 12M, and 12Y has four liquid ejection heads 18. Each liquid ejection head 18, which is a liquid ejection section, has a plurality of nozzles 19 and ejects ink (liquid) from each nozzle 19 onto the sheet S. The liquid ejection heads 18 are arranged alternately across the entire width direction of the image formation area on the sheet S, and when the sheet S is transported to a position facing each of the head units 12K, 12C, 12M, and 12Y, ink is ejected from each liquid ejection head 18, and an image is formed on the sheet S.

[0023] The "width direction" of the sheet S here refers to a direction parallel to the conveying surface along which the sheet is conveyed and perpendicular to the sheet conveying direction A, and refers to the direction indicated by arrow B in FIG. 3. The "conveying surface" refers to a surface through which the conveyed sheet passes, and includes, for example, an imaginary surface connecting the contact points between the sheet and multiple conveying rollers that convey the sheet, or the sheet placement surface of a conveying belt that places and conveys the sheet. The "sheet width direction" in the following description also has the same meaning.

[0024] Next, the configuration of the conveying device 20 (conveying section 8) disposed in the first image forming section 3 will be described with reference to FIG.

[0025] As shown in Fig. 4, the conveying device 20 (conveying section 8) has a plurality of conveying rollers 17. Of the conveying rollers 17 shown in Fig. 4, the conveying rollers 17A and 17B at the most upstream and most downstream positions in the sheet conveying direction A are two pairs of drive rollers that sandwich and convey the sheet S from its front and back sides. In addition to these drive rollers 17A and 17B, the sheet S is conveyed by a drive roller 17C (unpaired conveying roller) that is arranged one position downstream of the upstream drive roller 17A.

[0026] Furthermore, a plurality of driven rollers 17d to 17k are disposed between the upstream drive roller 17C and the downstream drive roller 17B as the conveying rollers 17. A plurality of drive rollers may be disposed instead of the driven rollers 17d to 17k. The driven rollers 17d to 17k are disposed on the upstream and downstream sides of the liquid ejection positions 10K, 10C, 10M, and 10Y of the head units 12K, 12C, 12M, and 12Y, respectively. In this manner, by disposing the driven rollers 17d to 17k on the upstream and downstream sides of the liquid ejection positions 10K, 10C, 10M, and 10Y, respectively, flapping of the sheet S, particularly at the liquid ejection positions 10K, 10C, 10M, and 10Y, is suppressed, and the sheet S can be conveyed stably.

[0027] However, if the conveying roller 17 is eccentric or thermally expands, as shown in Fig. 5, the conveyed sheet S may be displaced in the width direction B, causing the sheet S to meander when conveyed. When such meandering of the sheet S occurs, the position of the ink that lands on the sheet S also shifts, resulting in a problem of reduced image quality. Therefore, in this embodiment, when meandering of the sheet S occurs, the cyan, magenta, and yellow head units 12C, 12M, and 12Y are configured to be movable in the width direction B of the sheet S so that they can follow the meandering (misalignment in the width direction) (see the state indicated by the two-dot chain line in Fig. 5).

[0028] Furthermore, in order to make the positions of the head units 12C, 12M, and 12Y follow the meandering of the sheet S, it is necessary to grasp the positional deviation (the direction and amount of positional deviation) in the width direction B of the sheet S. For this reason, as shown in FIG. 4, the conveying device 20 according to this embodiment is provided with a plurality of position sensors 30 as position detection units that detect the position of the sheet S.

[0029] Each position sensor 30 is disposed on the opposite side of the conveyance path along which the sheet S is conveyed from the head units 12K, 12C, 12M, and 12Y (below the sheet S in FIG. 4), near each liquid ejection position 10K, 10C, 10M, and 10Y where ink is ejected from each head unit 12K, 12C, 12M, and 12Y. That is, each position sensor 30 is disposed between the driven rollers 17d to 17k disposed upstream and downstream of each liquid ejection position 10K, 10C, 10M, and 10Y. Note that in this specification, the term "liquid ejection position" refers to the liquid ejection position when the sheet is not meandering, i.e., when the head unit is not moving in the sheet width direction and is positioned at a preset reference position (initial position).

[0030] An optical sensor capable of detecting surface information of the transported object is used as the position sensor 30. For example, a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera that uses air pressure, photoelectricity, ultrasonic waves, or light such as visible light, laser, or infrared light is used.

[0031] Fig. 6 is a block diagram showing a control system for the position sensor and head unit according to this embodiment. Below, the control of the position sensor and head unit will be described with reference to Fig. 6, taking as an example a combination of a first position sensor 30A that detects the position of the sheet S at the position of the black head unit 12K and a second position sensor 30B that detects the position of the sheet S at the position of the cyan head unit 12C.

[0032] As shown in FIG. 6, the first position sensor 30A and the second position sensor 30B are configured by an imaging unit 31, an imaging control unit 32, and an image storage unit 33.

[0033] The imaging unit 31 is a part that captures an image of the sheet S being conveyed.

[0034] The imaging control unit 32 has a shutter control unit 34 and an image capturing unit 35. The shutter control unit 34 controls the timing at which the imaging unit 31 captures an image. The image capturing unit 35 acquires data of the image captured by the imaging unit 31.

[0035] The image storage unit 33 stores the image data captured by the imaging control unit 32 .

[0036] Since the sheet S is a material with scattering properties on its surface or inside, when laser light is irradiated onto the sheet S from the laser light sources of each position sensor 30A, 30B, the reflected light is diffused. This diffuse reflection forms a pattern on the sheet S. This pattern is a speckle pattern, an example of surface information. When the sheet S is imaged, image data showing the speckle pattern is obtained. The position of the pattern can be determined from this image data, making it possible to detect where a predetermined position on the sheet S is located. In other words, when the sheet S is transported, the pattern on the sheet S is also transported, so by detecting the same pattern at different times, the movement amount or movement speed of the sheet S can be determined.

[0037] The image data captured by the first position sensor 30A and the second position sensor 30B is sent to a calculation unit 36 ​​included in the control unit 9. The calculation unit 36 ​​calculates how much a predetermined portion on the sheet S has moved in the sheet width direction based on the image data sent from the first position sensor 30A and the second position sensor 30B. Then, based on the movement amount (positional deviation amount) of the sheet S calculated by the calculation unit 36, the cyan head unit 12C is moved in the sheet width direction, thereby controlling the ejection position in the sheet width direction. Furthermore, with other combinations of position sensors 30, the positional deviation of the sheet S can be detected in the same manner, and the magenta and yellow head units 12M and 12Y can be moved in the sheet width direction based on the detected positional deviation amount, thereby controlling the respective ejection positions in the sheet width direction.

[0038] Furthermore, based on the image data captured by each position sensor 30, it is possible to detect misalignment in the sheet width direction as well as in the sheet transport direction. For example, the calculation unit 36 ​​can calculate the amount of misalignment of the sheet S in the sheet transport direction based on the image data sent from the first position sensor 30A and the second position sensor 30B, by calculating how much a specific portion of the sheet S has moved in the sheet transport direction. Other combinations of position sensors 30 can also detect misalignment in the sheet transport direction in a similar manner. The sheet S may stretch in the sheet transport direction due to ink seepage. In such cases, the ejection timing of each head unit 12K, 12C, 12M, and 12Y is controlled based on the calculated amount of misalignment in the sheet transport direction. This allows the ejection position in the sheet transport direction to be controlled.

[0039] Furthermore, in order to improve the detection accuracy of each position sensor 30, it is preferable that each position sensor 30 is disposed between rollers such as driven rollers 17d to 17k, as shown in Fig. 4. Since the conveying speed of the sheet S is relatively stable between the rollers, by disposing each position sensor 30 between the rollers, it is possible to accurately detect the movement amount or movement speed of the sheet S in at least one of the sheet conveying direction and the sheet width direction.

[0040] Furthermore, it is preferable that the position of each position sensor 30 is close to each liquid ejection position 10K, 10C, 10M, and 10Y where the ink is ejected. In other words, the shorter the distance between the position sensor 30 and the liquid ejection positions 10K, 10C, 10M, and 10Y, the smaller the detection error, and therefore the more accurately the positional deviation of the sheet S can be detected.

[0041] Furthermore, it is preferable that each position sensor 30 is disposed upstream of each liquid ejection position 10K, 10C, 10M, and 10Y. When each position sensor 30 is disposed upstream of each liquid ejection position 10K, 10C, 10M, and 10Y, it is possible to control the movement of the head unit or the ejection timing after the position sensor 30 detects the position of the sheet S and before the sheet S is transported to each liquid ejection position 10K, 10C, 10M, and 10Y.

[0042] On the other hand, if the position sensors 30 are disposed directly below the liquid ejection positions 10K, 10C, 10M, and 10Y, there is a risk that the ink landing position will be shifted due to a delay in the control operation. However, if the control operation can be performed quickly, it is preferable to dispose the position sensors 30 directly below the liquid ejection positions 10K, 10C, 10M, and 10Y rather than upstream of them, because this allows for accurate detection of the amount of movement of the sheet S directly below the liquid ejection positions 10K, 10C, 10M, and 10Y. Furthermore, if an error due to the control operation is acceptable, the position sensors 30 may be disposed downstream of the liquid ejection positions 10K, 10C, 10M, and 10Y.

[0043] In this embodiment, the intervals D1 to D3 (see FIG. 4) between the position sensors 30 in the sheet conveying direction A are set to be integer multiples of the circumferential length X of a drive roller (for example, the lower drive roller of the most downstream roller pair 17B shown in FIG. 4) that conveys the sheet S. That is, the intervals D1 to D3 from the most upstream position sensor 30A shown in FIG. 4 to the position sensors 30B to 30D further downstream are set to be 1, 2, and 3 times the circumferential length X of the drive roller (D1=X, D2=2X, D3=3X).

[0044] In this way, by setting the intervals D1 to D3 between the position sensors 30 to lengths that are integer multiples of the circumferential length X of the drive roller, even if the drive roller is eccentric, the speed unevenness of the sheet S caused by the eccentricity can be offset at the detection position of each position sensor 30. Therefore, each position sensor 30 can detect the positional deviation of the sheet S with high accuracy.

[0045] Similarly, the intervals E1 to E3 between the head units 12K, 12C, 12M, and 12Y in the sheet conveying direction A are set to be 1, 2, and 3 times the circumferential length X of the drive roller (E1=X, E2=2X, E3=3X). This makes it possible to cancel out unevenness in the speed of the sheet S caused by eccentricity of the drive roller at the liquid ejection positions 10K, 10C, 10M, and 10Y, and allows ink to be ejected from the head units 12K, 12C, 12M, and 12Y onto the sheet S with high precision.

[0046] Here, to improve the detection accuracy of each position sensor 30, in addition to setting the sensor placement location relative to the liquid ejection position as described above, it is also important to manage the installation accuracy when installing the sensor. Methods for improving sensor installation accuracy generally include increasing the dimensional accuracy of the installation parts or adjusting the position after installation, but these methods have problems such as increased costs due to stricter dimensional management of the installation parts and increased installation time due to position adjustment. Therefore, in this embodiment, the following configuration is adopted to enable easy and accurate installation of the sensors. The sensor installation structure according to this embodiment will be described below.

[0047] FIG. 7 is a perspective view showing the sensor mounting structure according to this embodiment.

[0048] As shown in FIG. 7 , the position sensor 30 is mounted between a pair of side plates 21A and 21B via two support shafts 22 and a sensor holder 23. The pair of side plates 21A and 21B are roller support members that support both ends (either ends or their vicinity) of the plurality of conveying rollers 17 and are arranged parallel to each other with a gap between them. The sensor holder 23 is a detection unit holding member that holds the position sensor 30 and is mounted across the two support shafts 22. Each support shaft 22 constitutes a detection unit support member that supports the position sensor 30 held by the sensor holder 23 and is mounted between the pair of side plates 21A and 21B. Furthermore, a flat fixing member 24 that fixes each support shaft 22 is mounted on one of the side plates 21A as a member that constitutes the detection unit support member. That is, the detection unit support member has the pair of support shafts 22 and the fixing member 24. As described above, the conveying device 20 according to this embodiment is provided with a pair of side plates 21A, 21B, two support shafts 22, a sensor holder 23, and a fixing member 24 as a mounting structure for mounting the position sensor 30.

[0049] Next, details of the sensor mounting structure and mounting method according to this embodiment will be described with reference to the exploded perspective views of Figures 8 to 12. In the following description, of the pair of side plates 21A, 21B shown in Figure 8, the side plate 21A on the near side of the figure will be referred to as the "first side plate," and the side plate 21B on the far side will be referred to as the "second side plate." Furthermore, the sides of the side plates 21A, 21B that face each other will be referred to as the "inside," and the opposite side will be referred to as the "outside."

[0050] 8, the first side plate 21A and the second side plate 21B are each provided with two insertion holes 25 having a circular cross section, into which each support shaft 22 is inserted. The insertion holes 25 are provided at the same height and at the same intervals so that when each support shaft 22 is inserted, the support shafts 22 are horizontal and parallel to each other.

[0051] As shown in Fig. 8, each support shaft 22 is inserted from the outside of the first side plate 21A toward the second side plate 21B in the direction of arrow C. A protrusion 220 having a circular cross section is provided at the tip of each support shaft 22 in the insertion direction C, and is inserted into an insertion hole 25 of the second side plate 21B. This protrusion 220 is formed with a smaller diameter than the other parts of the support shaft 22, and as shown in Fig. 9, when the protrusion 220 is inserted into the insertion hole 25 of the second side plate 21B, the large diameter portion 221 on the tip side (protrusion 220 side) of each support shaft 22 is also inserted into the insertion hole 25 of the second side plate 21B.

[0052] Furthermore, after each support shaft 22 is inserted into the insertion hole 25 of each side plate 21A, 21B, a fixing member 24 is attached to the first side plate 21A, thereby restricting the movement of each support shaft 22 in the insertion direction C and the opposite direction, and the rotation of each support shaft 22 around the axis of the insertion direction C.

[0053] 10 , a detent protrusion 222 having a D-shaped cross section is provided at the rear end (the end opposite to the front end in the insertion direction C) of each support shaft 22 to restrict rotation of each support shaft 22. Meanwhile, the fixed member 24 is formed with a fitting hole 241 having a D-shaped cross section, into which the detent protrusion 222 of each support shaft 22 is fitted. The detent protrusion 222 of the support shaft 22 is inserted into and fitted into the fitting hole 241 of the fixed member 24, thereby restricting rotation of the support shaft 22 relative to the fixed member 24. Note that the cross-sectional shapes of the detent protrusion 222 and the fitting hole 241 may be other non-circular cross-sectional shapes such as a rectangle, a polygon, an ellipse, etc., other than a D-shape.

[0054] 10, the anti-rotation protrusion 222 is provided with a screw hole 224. A screw 27 is fastened into this screw hole 224 from the outside of the fixing member 24, thereby fixing the support shaft 22 to the fixing member 24. The fixing member 24 is also provided with a screw insertion hole 240 for attaching the fixing member 24 to the first side plate 21A. Meanwhile, the first side plate 21A is provided with a screw hole 210 for attaching the fixing member 24. A screw 26 is inserted into the screw insertion hole 240 of the fixing member 24 and fastened into the screw hole 210 of the first side plate 21A, thereby attaching the fixing member 24 to the outer surface of the first side plate 21A.

[0055] 9, when the support shafts 22 are fixed to the fixing members 24 and the fixing members 24 are further fixed to the first side plate 21A, movement of the support shafts 22 relative to the first side plate 21A in the insertion direction C and in the opposite direction is restricted. In this state, the engagement holes 241 of the fixing members 24 are fitted into the anti-rotation protrusions 222 of the support shafts 22, so that rotation of the support shafts 22 relative to the first side plate 21A is also restricted.

[0056] FIG. 11 is an exploded perspective view showing the sensor holder 23 before it is attached to each support shaft 22. As shown in FIG.

[0057] 11, a mounting surface 225 for mounting the sensor holder 23 is provided on the surface of each support shaft 22. The mounting surface 225 is flat, and when the rotation of the support shaft 22 relative to the first side plate 21A is restricted, the mounting surface 225 faces upward (toward the conveying path) and is disposed horizontally.

[0058] The mounting surface 225 is provided with two positioning recesses 226a and 226b as positioning portions for positioning the sensor holder 23. Of the two positioning recesses 226a and 226b, the positioning recess 226a is a round hole that serves as a primary positioning reference, and the other positioning recess 226b is an elongated hole that serves as a secondary positioning reference. The mounting surface 225 also has two screw holes 227 for attaching the sensor holder 23.

[0059] 11, the sensor holder 23 has a base portion 230 attached to the attachment surface 225 of the support shaft 22, and a sensor attachment portion 231 to which the position sensor 30 is attached. The base portion 230 and the sensor attachment portion 231 are arranged perpendicular to each other, and when the base portion 230 is arranged horizontally, the sensor attachment portion 231 is arranged to extend vertically downward from the base portion 230. The base portion 230 is provided with two positioning protrusions 232 as positioning portions to be inserted into the positioning recesses 226a, 226b provided in the attachment surface 225. When the positioning protrusions 232 are inserted into the positioning recesses 226a, 226b, movement of the sensor holder 23 relative to the support shaft 22 is restricted in the horizontal direction (direction parallel to the attachment surface 225). At this time, since the base portion 230 is placed on the mounting surface 225 of the support shaft 22, downward movement of the sensor holder 23 relative to the support shaft 22 (direction perpendicular to the mounting surface 225) is also restricted.

[0060] In this embodiment, to standardize components, the positioning recesses 226a, 226b are provided on both of the support shafts 22, but the positioning protrusion 232 of the sensor holder 23 is inserted into the positioning recesses 226a, 226b of only one of the support shafts 22. In this way, the sensor holder 23 only needs to be positioned based on the positioning recesses 226a, 226b of at least one of the support shafts 22. The sensor holder 23 may also be positioned based on the positioning recesses 226a, 226b of both of the support shafts 22. The relationship between the recesses and protrusions of the positioning portions of the sensor holder 23 and the support shaft 22 may be reversed from that in this embodiment. That is, the positioning recesses may be provided in the sensor holder 23, and the positioning protrusions may be provided on the mounting surface 225 of the support shaft 22.

[0061] 11 , a base portion 230 of the sensor holder 23 is provided with a plurality of screw insertion holes 233 for attaching the sensor holder 23 to each support shaft 22. With the sensor holder 23 positioned relative to the attachment surface 225 of each support shaft 22, screws 28 are inserted into the screw insertion holes 233 of the sensor holder 23 and fastened into screw holes 227 provided in each attachment surface 225, thereby attaching the sensor holder 23 to the attachment surface 225 of each support shaft 22.

[0062] FIG. 12 is an exploded perspective view showing the position sensor 30 before it is attached to the sensor holder 23. As shown in FIG.

[0063] 12, the sensor mounting portion 231 of the sensor holder 23 is provided with a plurality of positioning protrusions 234 as positioning portions for positioning the position sensor 30. As indicated by the two-dot chain lines in FIG. 12, the position sensor 30 is restricted from moving downward and rightward in the drawing by contacting each of the positioning protrusions 234 of the sensor holder 23. That is, the position sensor 30 has a main body portion 301 constituting the imaging unit and the like, a lens portion 302, and an illumination portion 303, and the positioning protrusions 234 come into contact with two mutually orthogonal planes (the bottom surface and the right surface in FIG. 12) of the main body portion 301 formed in a hexahedral (cubic or rectangular parallelepiped) shape, thereby restricting movement of the position sensor 30 in directions perpendicular to the two planes.

[0064] Furthermore, the sensor mounting portion 231 of the sensor holder 23 is provided with a plurality of screw insertion holes 235 for mounting the position sensor 30. Meanwhile, the main body 301 of the position sensor 30 is provided with a plurality of screw holes 304. With the position sensor 30 positioned relative to the sensor holder 23, the screws 29 are fastened through the screw insertion holes 235 of the sensor mounting portion 231 into the screw holes 304 of the position sensor 30, thereby mounting the position sensor 30 to the sensor holder 23. In this embodiment, two screw insertion holes 235 and two positioning protrusions 234 are provided in the sensor mounting portion 231 so that the number of position sensors 30 mounted on the sensor holder 23 can be increased to two and the mounting positions can be selected.

[0065] In the present embodiment configured as described above, to attach the position sensor 30 between the side plates 21A and 21B, first, as shown in FIG. 8, the two support shafts 22 are inserted into the insertion holes 25 from the outside of the first side plate 21A, and the tips (projections 220) of the support shafts 22 are inserted into the insertion holes 25 of the second side plate 21B. Note that in this embodiment, the insertion holes 25 of the first side plate 21A are formed with a larger diameter on the front side than on the back side in the insertion direction C (see FIG. 9). Therefore, for example, even if the insertion holes 25 of the side plates 21A and 21B are slightly misaligned from each other, the support shafts 22 can be smoothly inserted from the insertion holes 25 of the first side plate 21A to the insertion holes 25 of the second side plate 21B by tilting the support shafts 22 within the insertion holes 25 of the first side plate 21A.

[0066] Next, the mounting surfaces 225 of the support shafts 22 inserted into the insertion holes 25 are aligned so that they face upward, and the fixing member 24 is attached from the outside of the first side plate 21A. At this time, as shown in FIG. 10 , the fixing member 24 is positioned so that the anti-rotation protrusions 222 of the support shafts 22 fit into the fitting holes 241 of the fixing member 24. Then, screws 26, 27 are fastened to the screw holes 224 provided in the anti-rotation protrusions 222 and the screw holes 240 provided in the fixing member 24, respectively. As a result, the fixing member 24 is fixed to the first side plate 21A, and each support shaft 22 is fixed to the fixing member 24.

[0067] 12, the position sensor 30 is attached to the sensor holder 23. First, the position sensor 30 is brought into contact with the multiple positioning protrusions 234 of the sensor holder 23 to be positioned, and while maintaining this position, the screws 29 are passed through the screw insertion holes 235 of the sensor holder 23 and fastened into the screw holes 304 of the position sensor 30. This completes the attachment of the position sensor 30 to the sensor holder 23.

[0068] Then, the sensor holder 23 with the position sensor 30 attached thereto is attached onto each support shaft 22 fixed between the pair of side plates 21A, 21B. First, as shown in FIG. 11 , the sensor holder 23 is positioned by inserting each positioning protrusion 232 provided on the sensor holder 23 into each positioning recess 226a, 226b provided on the mounting surface 225 of one of the support shafts 22. Next, screws 28 are passed through the screw insertion holes 233 of the sensor holder 23 and fastened into the screw holes 227 of the mounting surface 225, thereby attaching the sensor holder 23 onto each support shaft 22. This completes the installation of the position sensor 30.

[0069] As described above, in this embodiment, when installing the position sensor 30, the installation work can be performed while positioning each component relative to each other, so that the installation of the position sensor 30 can be performed easily and accurately without the need for strict dimensional control of the components or position adjustment after installation.

[0070] That is, in this embodiment, each support shaft 22 supporting the position sensor 30 is inserted into an insertion hole 25 provided in the pair of side plates 21A, 21B, thereby being positioned in a direction intersecting the insertion direction C (radial direction). Furthermore, with each support shaft 22 inserted into the insertion hole 25, each support shaft 22 is fixed to the first side plate 21A via the fixing member 24, thereby positioning each support shaft 22 relative to the first side plate 21A in the insertion direction C and the opposite direction thereto (axial direction). Furthermore, a rotation prevention protrusion 222 provided on the rear end of each support shaft 22 is fitted into a fitting hole 241 of the fixing member 24, thereby positioning each support shaft 22 relative to the first side plate 21A in a rotation direction about the axis of the insertion direction C.

[0071] Thus, in this embodiment, a pair of side plates 21A, 21B have insertion holes 25 into which each support shaft 22 is inserted and which position each support shaft 22 in a direction intersecting the insertion direction C, and the fixing member 24 functions as a positioning part which positions each support shaft 22 relative to the first side plate 21A in the insertion direction C and the opposite direction, and in the rotational direction around the axis of the insertion direction C. Therefore, each support shaft 22 can be easily positioned by simply inserting each support shaft 22 into the insertion hole 25 and attaching the fixing member 24.

[0072] Furthermore, in this embodiment, because each support shaft 22 is inserted into the insertion hole 25 from the outside of the first side plate 21A, the number of mounting parts can be reduced and the mounting work can be simplified compared to the configuration shown in FIG. 13 in which the support shafts 22 are inserted into the insertion hole 25 from the inside of the first side plate 21A. That is, in the example shown in FIG. 13, the support shafts 22 are tilted and their tips are inserted into the insertion holes 25 from the inside of the first side plate 21A, and then, as shown in FIG. 14, the support shafts 22 need to be horizontally positioned and their rear ends inserted into the insertion holes 25 of the second side plate 21B. However, because the support shafts 22 are inserted at an angle, the insertion holes 25 of the first side plate 21A must be formed with a diameter significantly larger than that of the support shafts 22. Therefore, when the support shafts 22 are horizontally positioned, a separate member such as a bearing 40 is required to support the tips of the support shafts 22 relative to the insertion holes 25 of the first side plate 21A, as shown in FIG. 15. In contrast, in this embodiment, the support shaft 22 is inserted into the insertion hole 25 from the outside of the first side plate 21A, so that the insertion hole 25 in the first side plate 21A can be formed to have the same diameter as the support shaft 22, eliminating the need for a separate bearing or the like. Therefore, the support shaft 22 can be easily attached with a small number of parts. Note that the present invention does not exclude a configuration in which the support shaft 22 is inserted from the inside of the first side plate 21A, as shown in Figures 13 to 15. If a member such as a bearing 40 is provided, such a configuration can also be adopted.

[0073] Furthermore, in this embodiment, each support shaft 22 can be inserted from the insertion hole 25 of the same side plate (first side plate 21A) of the pair of side plates 21A, 21B toward the insertion hole 25 of the other side plate (second side plate 21B), facilitating the installation of each support shaft 22. For example, if there is an obstacle on the second side plate 21B side that makes it difficult to insert and screw-fasten each support shaft 22 from the second side plate 21B side, the installation can be facilitated by inserting and screw-fastening each support shaft 22 from the first side plate 21A side. Furthermore, there is no need to change the insertion direction for each support shaft 22, which improves work efficiency.

[0074] Furthermore, in this embodiment, each support shaft 22 is fixed to the first side plate 21A via the fixing member 24, thereby positioning each support shaft 22 relative to the first side plate 21A in the insertion direction C and the opposite direction thereto (axial positioning). On the other hand, with respect to the second side plate 21B, the tip of each support shaft 22 is simply inserted into the insertion hole 25 (see FIG. 9), and therefore positioning of each support shaft 22 in the insertion direction C and the opposite direction thereto (axial positioning) is not performed. As such, in this embodiment, positioning of each support shaft 22 relative to the second side plate 21B in the insertion direction C and the opposite direction thereto (axial positioning) is not performed, and each support shaft 22 is not constrained in the axial direction. Therefore, even if each support shaft 22 expands or contracts in the axial direction due to a temperature rise after attachment, each side plate 21A, 21B is less likely to be directly affected by the expansion or contraction of the support shaft 22. Therefore, deformation such as bending of the side plates 21A, 21B due to expansion and contraction of the support shafts 22 can be suppressed, and the positional accuracy of the support shafts 22 can be improved.

[0075] Furthermore, as described above, each support shaft 22 is positioned relative to the same side plate (first side plate 21A) via the fixing member 24, thereby improving the positioning accuracy of each support shaft 22. That is, each support shaft 22 is positioned in the insertion direction C and the opposite direction thereof using the same side plate (first side plate 21A) as a reference, so positioning can be performed with greater accuracy than when positioning is performed using different side plates as a reference. In this way, in this embodiment, each support shaft 22 can be positioned with high accuracy, so the attachment accuracy of the position sensor 30 supported by each support shaft 22 is also improved.

[0076] Furthermore, the sensor mounting structure according to this embodiment simplifies the installation of additional position sensors 30 and maintenance work. For example, if an extra insertion hole 25 for installing an additional sensor is provided in each of the side plates 21A and 21B in advance, the support shaft 22 can be easily installed by inserting the support shaft 22 into the additional insertion hole 25 from the outside of the first side plate 21A when necessary. Furthermore, the sensor holder 23 can be fastened and fixed to the additional support shaft 22 from above with a screw, making installation work easy. Similarly, replacement or relocation of the position sensor 30 can also be easily performed from above the support shaft 22.

[0077] 16, the fitting holes 211 (positioning portions in the rotation direction) having a D-shaped cross section and fitting with the anti-rotation protrusions 222 of each support shaft 22 may be provided directly in one of the side plates 21A. In this case, the positioning portions for positioning each support shaft 22 in the rotation direction are made up of the anti-rotation protrusions 22 provided on each support shaft 22 and the fitting holes 211 provided in one of the side plates 21A. In the example shown in FIG. 16, the fitting holes 211 provided in one of the side plates 21A function as positioning portions in the rotation direction that restrict the rotation of the support shafts 22 by fitting with the anti-rotation protrusions 222 provided on the support shafts 22, and also function as positioning portions in the radial direction (insertion holes 25) that support the support shafts 22 in a direction intersecting with the insertion direction C. In this case, when the anti-rotation projections 222 of the support shafts 22 are inserted into the fitting holes 211 from the inside of one of the side plates 21A, not only are the support shafts 22 positioned in the rotational direction and in the direction (radial direction) intersecting the insertion direction C, but also the end face on the tip side of the support shafts 22 abuts against one of the side plates 21A, whereby the support shafts 22 are positioned in the insertion direction C (axial direction). Note that in this case, at least one of the pair of side plates 21A, 21B is configured to be able to move toward and away from the other, and after the tips of the support shafts 22 are inserted into the insertion holes 25 of one of the side plates 21A, the other side plate 21B is moved toward the rear ends of the support shafts 22, whereby the rear ends of the support shafts 22 are inserted into the insertion holes 25 of the other side plate 21B. As a result, each support shaft 22 is sandwiched between the pair of side plates 21A, 21B, and the support shafts 22 are positioned relative to the side plates 21A, 21B in the insertion direction C and the opposite direction.

[0078] 17, when the protrusion 220 at the tip of each support shaft 22 is inserted into the insertion hole 25 of the second side plate 21B, the end face of the large diameter portion 221 on the tip side (the protrusion 220 side) of each support shaft 22 may abut against the edge of the insertion hole 25 of the second side plate 21B (the inner surface of the second side plate 21B), thereby positioning each support shaft 22 in the insertion direction C. In this case, each insertion hole 25 of the second side plate 21B is formed with a diameter larger than the protrusion 220 and smaller than the end face of the large diameter portion 221 so that the end face of the large diameter portion 221 of each support shaft 22 can abut against it.

[0079] 18, the support shaft 22 may have a plurality of mounting surfaces 225 provided at different positions in the axial direction of the support shaft 22. For example, when the widthwise position reference of the sheet S in the first image forming unit 3 is the front side, the sensor holder 23 may be attached to the front mounting surface 225 of the support shaft 22, and then, in the second image forming unit 4 where the sheet S is conveyed upside down, the widthwise position reference of the sheet S is the rear side, so the sensor holder 23 may be attached to the rear mounting surface 225 of the support shaft 22. In this way, by providing a plurality of mounting surfaces 225 on the support shaft 22, it is possible to appropriately select the position of the position sensor 30 depending on the widthwise position reference of the sheet S, etc.

[0080] Although the embodiment of the present invention has been described above using a conveying device mounted in an inkjet image forming apparatus as an example, the present invention is not limited to inkjet image forming apparatuses such as those described above, and can also be applied to a conveying device mounted in an electrophotographic image forming apparatus such as that shown in Fig. 19. The configuration of an electrophotographic image forming apparatus to which the present invention is applied will now be described.

[0081] The image forming apparatus 200 shown in FIG. 19 is a tandem type image forming apparatus that includes four process units 61Y, 61C, 61M, and 61Bk as image forming units.

[0082] Each process unit 61Y, 61C, 61M, 61Bk includes a drum-shaped photosensitive member 62 as a latent image carrier, a charging roller 63 as a charging means for charging the surface of the photosensitive member 62, a developing device 64 as a developing means for forming a toner image on the surface of the photosensitive member 62, and a cleaning blade 65 as a cleaning means for cleaning the surface of the photosensitive member 62.

[0083] 19, an exposure device 66 is disposed above each of the process units 61Y, 61C, 61M, and 61Bk. The exposure device 66 includes a light source, a polygon mirror, an f-θ lens, a reflecting mirror, and the like, and irradiates the surface of each photoconductor 62 with laser light based on image data.

[0084] 19, a transfer device 67 is disposed below each of the process units 61Y, 61C, 61M, and 61Bk. The transfer device 67 has an intermediate transfer belt 68 formed of an endless belt as a transfer body, a plurality of primary transfer rollers 70 that form primary transfer nips with each of the photosensitive bodies 62, and a secondary transfer roller 71 that forms a secondary transfer nip with the intermediate transfer belt 68.

[0085] The image forming apparatus 200 also includes a paper feed cassette 72 that stores sheets S as recording media, a paper feed roller 73 that feeds the sheets S from the paper feed cassette 72, a timing roller 74 that transports the fed sheets S to the secondary transfer nip at a predetermined timing, a fixing device 75 that fixes an image on the sheets S, a cooling device 76 that cools the sheets S, a pair of paper discharge rollers 77 that discharge the sheets S outside the apparatus, and a paper discharge tray 78 on which the discharged sheets S are placed.

[0086] The image forming apparatus 200 shown in FIG. 19 operates as follows.

[0087] When the image formation operation begins, the photoconductors 62 of each process unit 61Y, 61C, 61M, and 61Bk are rotated counterclockwise in the drawing, and the surfaces of each photoconductor 62 are uniformly charged to a predetermined polarity by the charging rollers 63. Then, based on the image information of the original document read by the reading device, the exposure device 66 irradiates the charged surface of each photoconductor 62 with laser light, forming an electrostatic latent image on the surface of each photoconductor 62. At this time, the image information exposed to each photoconductor 62 is monochromatic image information obtained by decomposing a desired full-color image into yellow, cyan, magenta, and black color information. The electrostatic latent images thus formed on the photoconductors 62 are developed (visible) as toner images by the developing devices 64.

[0088] In the transfer device 67, one of the rollers 69A-69D supporting the intermediate transfer belt 68 rotates as a drive roller, causing the intermediate transfer belt 68 to rotate in the direction of the arrow in FIG. 19 . A constant voltage or constant current controlled voltage of opposite polarity to the toner charge polarity is applied to each primary transfer roller 70, thereby forming a transfer electric field in the primary transfer nip between each primary transfer roller 70 and each photoconductor 62. The toner images of each color formed on each photoconductor 62 are then transferred onto the intermediate transfer belt 68 in a sequentially overlapping manner by the transfer electric field formed in the primary transfer nip. Thus, a full-color toner image is carried on the intermediate transfer belt 68. Any toner remaining on each photoconductor 62 that has not been transferred to the intermediate transfer belt 68 is removed by a cleaning blade 65.

[0089] The toner image transferred onto the intermediate transfer belt 68 is transported to the secondary transfer nip (the position of the secondary transfer roller 71) as the intermediate transfer belt 68 rotates, and is transferred onto the transported sheet S by the timing roller 74. This sheet S is supplied from the paper feed cassette 72. After a command to start the printing operation is received from the paper feed cassette 72, the paper feed roller 73 rotates to feed the sheets S one by one. The fed sheet S is then stopped temporarily by a pair of timing rollers 74 and then transported to the secondary transfer nip in time with the toner image on the intermediate transfer belt 68 reaching the secondary transfer nip. At this time, a transfer voltage of opposite polarity to the charge polarity of the toner image on the intermediate transfer belt 68 is applied to the secondary transfer roller 71, and the toner image on the intermediate transfer belt 68 is transferred onto the sheet S by the transfer electric field formed by this transfer voltage.

[0090] Thereafter, the sheet S is conveyed to the fixing device 75, where the toner image on the sheet S is heated and pressed by a fixing roller 81 and a pressure roller 82 provided in the fixing device 75, thereby fixing the toner image to the sheet S. The sheet S is then conveyed to a cooling device 76 where it is cooled, and then discharged onto a paper discharge tray 78 by a pair of paper discharge rollers 77. This completes the series of image forming operations.

[0091] Here, the cooling device 76 provided in the image forming apparatus 200 has the following configuration.

[0092] 20, the cooling device 76 includes a pair of conveyor belts 51A and 51B. Each of the conveyor belts 51A and 51B is configured as an endless belt member, and is stretched by a pair of conveyor rollers 52. At least one of the conveyor rollers 52 is a drive roller that is driven to rotate by a drive source such as a motor, and the conveyor belts 51A and 51B rotate when the conveyor roller 52 is driven to rotate. As a result, the sheet S is conveyed while being sandwiched between the conveyor belts 51A and 51B.

[0093] 19, cooling members 53A and 53B are disposed inside the pair of conveyor belts 51A and 51B, respectively. Each cooling member 53A and 53B is pressed against the inner circumferential surface of each conveyor belt 51A and 51B by a spring 54 serving as a pressure means, and is in contact with the inner circumferential surface of each conveyor belt 51A and 51B. Therefore, when a sheet S is conveyed between the conveyor belts 51A and 51B, the sheet S is cooled from both the front and back sides by each cooling member 53A and 53B while being conveyed by the rotating conveyor belts 51A and 51B.

[0094] In a cooling device 76 equipped with a pair of conveyor belts 51A and 51B as described above, if the conveyor rollers 52 supporting the conveyor belts 51A and 51B are eccentric, there is a risk that the conveyor belts 51A and 51B may meander (become misaligned in the sheet width direction). Therefore, in the cooling device 76 shown in FIG. 20, position sensors 55 for detecting the positions of the conveyor belts 51A and 51B are disposed inside the conveyor belts 51A and 51B. These position sensors 55 detect the surfaces of the conveyor belts 51A and 51B to determine whether the conveyor belts 51A and 51B meander. If the conveyor belts 51A and 51B meander, the positions of the conveyor belts 51A and 51B (in the sheet width direction) are corrected by a meander correction unit 56 provided on the conveyor rollers 52.

[0095] Thus, in a cooling device 76 equipped with a position sensor 55 for detecting meandering of the conveyor belts 51A and 51B, the accuracy of installation of the position sensor 55 affects the accuracy of meandering detection. Therefore, it is preferable to apply the sensor installation structure according to the present invention to such a cooling device 76, as in the conveyor device according to the above embodiment. This allows for simple and accurate installation of the sensor, improving the accuracy of meandering detection. Furthermore, the present invention is not limited to conveyor devices that function as such cooling devices 76, but can also be applied to conveyor devices other than cooling devices, such as a transfer device 67 equipped with an intermediate transfer belt 68 as shown in FIG. 19.

[0096] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the scope of the invention.

[0097] Here, the "liquid ejection device" according to the present invention includes a device that has a liquid ejection head or a head unit and ejects liquid by driving the liquid ejection head. For example, the "liquid ejection device" includes not only a device that can eject liquid onto an object onto which the liquid can adhere, but also a device that ejects liquid into air or liquid.

[0098] Furthermore, the term "liquid ejection device" can also include means for feeding, transporting, and discharging objects onto which liquid can be attached, as well as other pre-processing devices, post-processing devices, etc. For example, "liquid ejection devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed by layering powder in order to form a three-dimensional object (a three-dimensional model).

[0099] Furthermore, the term "liquid ejection device" is not limited to devices that visualize meaningful images such as letters and figures using ejected liquid. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0100] Furthermore, the term "liquid ejection device" includes, but is not limited to, a device in which a liquid ejection head and an object onto which liquid can adhere move relatively. Specific examples include a serial type device in which a liquid ejection head ejects liquid while moving in the width direction of a sheet, and a line type device (see Figure 3) in which a liquid ejection head ejects liquid without moving in the width direction of a sheet.

[0101] Furthermore, the term "liquid ejection device" also includes a treatment liquid application device that ejects a treatment liquid onto the surface of a sheet for purposes such as modifying the surface of the sheet, and an injection granulation device that sprays a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0102] The "liquid ejection head" is a functional component that ejects or sprays liquid from nozzles. The ejected liquid may have any viscosity or surface tension that allows it to be ejected from the head. While not particularly limited, it is preferable for the viscosity of the ejected liquid to be 30 mPa·s or less at room temperature and pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or other functionalizing material, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural dye. These liquids can be used, for example, as inkjet inks, surface treatment solutions, components of electronic or light-emitting elements, liquids for forming resist patterns for electronic circuits, and liquid materials for 3D modeling.

[0103] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0104] In addition, in the present invention, a "head unit" refers to a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to liquid ejection. For example, a "head unit" includes a liquid ejection head combined with at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device. In addition to a head unit equipped with multiple liquid ejection heads as in the above embodiment, the head unit may also be equipped with a single liquid ejection head.

[0105] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism that are fixed to each other by fastening, bonding, engaging, etc., or a liquid ejection head and a functional part or mechanism that are held movably relative to each other. The liquid ejection head and the functional part or mechanism may also be configured to be detachable from each other.

[0106] For example, some head units integrate a liquid ejection head and a head tank. Others integrate the liquid ejection head and head tank by connecting them together with a tube or the like. A unit including a filter can also be added between the head tank and the liquid ejection head of these head units. Other head units integrate a liquid ejection head and a carriage. Still other head units integrate the liquid ejection head and a scanning movement mechanism by movably holding the liquid ejection head on a guide member that constitutes part of the scanning movement mechanism. Still other head units integrate the liquid ejection head, carriage, and main scanning movement mechanism.

[0107] The head unit may also be one in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which the liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism. There are also head units in which a tube is connected to a liquid ejection head on which a head tank or flow path components are attached, thereby integrating the liquid ejection head and supply mechanism.

[0108] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0109] Furthermore, the above-mentioned "object onto which a liquid can adhere" refers to an object to be transported onto which a liquid can at least temporarily adhere, such as an object onto which the liquid adheres and sticks, or an object onto which the liquid adheres and penetrates, etc. Specific examples include media such as paper, recording paper, film, cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0110] Furthermore, the material of "something to which a liquid can adhere" may be anything to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0111] Furthermore, the "sheet" may be a continuous sheet formed into a long length (such as roll paper) or a sheet cut to a predetermined size (such as cut paper). Furthermore, the present invention is also applicable to devices that transport objects other than sheets, such as belts. [Explanation of symbols]

[0112] 17 Conveyor roller 21A Side plate (roller support member) 21B side plate (roller support member) 22 Support shaft (detection unit support member) 24 Fixing member (detection unit support member, positioning unit) 25 Insertion hole 30 Position sensor (position detection unit) 220 Protrusion (positioning part) 222 Anti-rotation protrusion (positioning part) C Insertion direction S sheet (transported object) [Prior art documents] [Patent documents]

[0113] [Patent Document 1] Japanese Patent Application Publication No. 2018-130956

Claims

1. a conveying roller for conveying an object to be conveyed; a pair of roller support members for supporting both axial ends of the conveying roller; a position detection unit that detects the position of the object to be conveyed; a detection unit support member for supporting the position detection unit, the pair of roller support members each have an insertion hole into which the detection unit support member is inserted and which positions the detection unit support member in a direction intersecting with the insertion direction of the detection unit support member, A conveying device characterized in that the detection unit support member has a positioning unit that positions at least one of the pair of roller support members in the insertion direction and the direction opposite to the insertion direction, and in the rotational direction around the axis of the insertion direction, and a positioning unit that positions the position detection unit in the insertion direction, the direction opposite to the insertion direction, and the direction intersecting the insertion direction, relative to the detection unit support member.

2. a conveying roller for conveying an object to be conveyed; a pair of roller support members for supporting both axial ends of the conveying roller; a position detection unit that detects the position of the object to be conveyed; a detection unit support member for supporting the position detection unit, the pair of roller support members each have an insertion hole into which the detection unit support member is inserted and which positions the detection unit support member in a direction intersecting with the insertion direction of the detection unit support member, the detection unit support member has a positioning portion that performs positioning with respect to at least one of the pair of roller support members in the insertion direction and the direction opposite to the insertion direction, and in the rotation direction around an axis in the insertion direction, The conveying device is characterized in that the detection unit support member is inserted into the insertion hole from the side opposite to the opposing surfaces of the pair of roller support members.

3. a conveying roller for conveying an object to be conveyed; a pair of roller support members for supporting both axial ends of the conveying roller; a position detection unit that detects the position of the object to be conveyed; a detection unit support member for supporting the position detection unit, the pair of roller support members each have an insertion hole into which the detection unit support member is inserted and which positions the detection unit support member in a direction intersecting with the insertion direction of the detection unit support member, the detection unit support member has a positioning portion that performs positioning with respect to at least one of the pair of roller support members in the insertion direction and the direction opposite to the insertion direction, and in the rotation direction around an axis in the insertion direction, The detection unit support member is provided in plurality, A conveying device characterized in that each of the detection unit support members is inserted from the insertion hole of one of the pair of roller support members toward the insertion hole of the other roller support member.

4. a conveying roller for conveying an object to be conveyed; a pair of roller support members for supporting both axial ends of the conveying roller; a position detection unit that detects the position of the object to be conveyed; a detection unit support member for supporting the position detection unit, the pair of roller support members each have an insertion hole into which the detection unit support member is inserted and which positions the detection unit support member in a direction intersecting with the insertion direction of the detection unit support member, the detection unit support member has a positioning portion that performs positioning with respect to at least one of the pair of roller support members in the insertion direction and the direction opposite to the insertion direction, and in the rotation direction around an axis in the insertion direction, A conveying device characterized in that the detection unit support member is positioned only in a direction intersecting the insertion direction relative to one of the pair of roller support members, and is positioned in the insertion direction and the direction opposite to the insertion direction relative to the other roller support member, as well as in a direction intersecting the insertion direction.

5. The detection unit support member is provided in plurality, The conveying device according to claim 1 , wherein each of the detection unit support members is inserted from the insertion hole of one of the pair of roller support members toward the insertion hole of the other roller support member.

6. A conveying device as described in claim 1 or 2, wherein the detection unit support member is positioned only in a direction intersecting the insertion direction relative to one of the pair of roller support members, and is positioned in the insertion direction and the direction opposite to the insertion direction relative to the other roller support member, as well as in a direction intersecting the insertion direction.

7. The conveying device described in claim 4 or 6, wherein the detection unit support member has a support shaft that is inserted into the insertion hole and a fixing member that positions the support shaft relative to the other roller support member in the insertion direction, the direction opposite to the insertion direction, and the rotation direction.

8. The detection unit support member is provided in plurality, The conveying device according to claim 1 , wherein the position detector is held by a detector holding member that is attached across the two detector support members.

9. each of the detection unit support members has a mounting surface to which the detection unit holding member is attached; The conveying device according to claim 8 , wherein the detection unit support members are positioned in the rotational direction so that the attachment surfaces of the detection unit support members face the same direction.

10. a conveying device that conveys an object to be conveyed; A liquid ejection device including a liquid ejection unit that ejects liquid onto the transport object, A liquid ejection apparatus comprising the transport device according to claim 1 .

11. The liquid ejection device according to claim 10 , wherein the position detection unit is disposed on the opposite side of the transport path along which the object is transported from the liquid ejection unit.

Images