JP7463783B2 - Liquid ejection device - Google Patents

Description

The present invention relates to an encoder cleaning tool and a device for discharging liquid.

In a serial type inkjet printer, the encoder (also called the "encoder scale" or "encoder sheet") is an important component that determines the printing performance, and it is necessary to prevent or remove dirt on the surface.
Until now, encoder cleaning tools have involved users using, for example, a cloth or cotton swab included with the product, but this can be difficult to clean and can lead to users accidentally damaging the encoder.

For example, Patent Document 1 discloses an automatic cleaning mechanism for the purpose of automatically cleaning an encoder.
However, the technology of Patent Document 1 involves pressing a cleaning member against the encoder from one side to clean it, and there is a risk that a large force will be applied during cleaning, causing it to stretch in one direction.

The present invention aims to provide an encoder cleaning tool for cleaning the surface of an encoder scale mounted on a carriage.

In order to solve the above-mentioned problems, the present invention provides a liquid ejecting device comprising an inkjet head, a carriage which drives the inkjet head along a guide member, an encoder scale which is arranged along the guide member, and an encoder cleaning tool which has a cleaning member which clamps the encoder scale and contacts both sides of the encoder scale to clean it, wherein the encoder cleaning tool is detachable from the carriage, and both ends of the encoder scale in the longitudinal direction are fixed to a device which ejects liquid with a spring, and cleaning is performed so that the frictional force between the encoder cleaning tool and the encoder scale when cleaning the encoder scale is smaller than the elastic force of the spring.

The present invention provides an encoder cleaning tool for cleaning the surface of an encoder scale mounted on a carriage.

1 is an external perspective view illustrating an example of an image forming apparatus according to an embodiment; FIG. FIG. 2 is a perspective view of a main part of a carriage portion of the device. FIG. 2 is a side view of a carriage portion of the device. FIG. 2 is a schematic diagram illustrating an example of an encoder scale. 1A and 1B are schematic diagrams illustrating an example of an encoder cleaning tool according to a first embodiment. 13A and 13B are schematic diagrams illustrating an example of an encoder cleaning tool according to a second embodiment. 13A to 13C are diagrams illustrating an example of an encoder cleaning tool according to a third embodiment. 13A to 13C are schematic diagrams illustrating another example of the encoder cleaning tool according to the third embodiment. 6A and 6B are diagrams illustrating the relationship between the frictional force caused by the pressing of the cleaning member and the elastic force of a spring of the encoder scale. 10A to 10C are schematic diagrams illustrating examples of other shapes of the cleaning member. 1 is a plan view illustrating a main portion of an example of a device for discharging liquid according to the present invention; FIG. FIG. 2 is a plan view illustrating a main portion of an example of a liquid ejection unit according to the present invention. FIG. 13 is a front view illustrating still another example of the liquid ejection unit according to the present invention.

One embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiment shown below, and can be modified within the scope of what a person skilled in the art can imagine, such as other embodiments, additions, modifications, deletions, etc., and as long as the function and effect of the present invention are achieved in any aspect, it is included in the scope of the present invention. In addition, components and equivalent parts having the same configuration or function in each drawing are given the same reference numerals, and their description will be omitted.

First, a configuration example of an image forming apparatus will be described as an example of an apparatus that ejects liquid using the encoder cleaner of the embodiment.
1 and 2 are diagrams for explaining an outline of an example of an image forming apparatus, where FIG. 1 is an explanatory perspective view of the appearance of the image forming apparatus, and FIG. 2 is an explanatory plan view of a mechanism of the apparatus.

This image forming device is a serial type image forming device, and has an openable cover 101 on the top side of the device body 100, and the internal mechanism can be accessed by opening this cover 101.

As shown in FIG. 2, the mechanism supports the carriage 4 so that it can slide freely in the main scanning direction with a guide member 3 that is a guide member that is horizontally mounted on the left and right main side plates 1A and 1B, and moves the carriage 4 in the main scanning direction via a timing belt 8 that is tensioned between a drive pulley 6 and a driven pulley 7 by a main scanning motor 5.

The carriage 4 is fitted with a recording head unit (hereinafter also simply referred to as a "recording head") 11, which includes a liquid ejection head as an image forming means for ejecting droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K), and a head tank for supplying ink to the liquid ejection head. The recording head unit 11 is mounted on the carriage 4 with a nozzle row made up of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the droplet ejection direction facing downward. The multiple recording heads 11 are held by a head holder (not shown) to form a unit and are mounted on the carriage 4.

An encoder scale 15 is arranged along the main scanning direction of the carriage 4, and an encoder sensor 16 consisting of a transmission type photosensor that reads the scale (scale: position identification part) of the encoder scale 15 is attached to the carriage 4 side, and the encoder scale 15 and the encoder sensor 16 together form a linear encoder as a position detection device.

On the other hand, a conveyor belt 21 is disposed below the carriage 4 as a conveying means for conveying paper (not shown) in the sub-scanning direction. This conveyor belt 21 is an endless belt that is stretched between a conveyor roller 22 and a tension roller 23, and is moved in a circular motion in the sub-scanning direction by a sub-scanning motor 31 rotating the conveyor roller 22 via a timing belt 32 and a timing pulley 33.

Furthermore, a maintenance and recovery mechanism 415 that maintains and recovers the recording head 11 is disposed on one side of the carriage 4 in the main scanning direction, beside the conveyor belt 21. The maintenance and recovery mechanism 415 is composed of, for example, a cap member that caps the nozzle surface (the surface on which the nozzles are formed) of the recording head 11, a wiper member that wipes the nozzle surface, and a blank discharge receiver that discharges droplets that do not contribute to image formation.

As shown in FIG. 1, a paper feed tray 103 is detachably attached to the device body 100. The paper feed tray 103 comprises a paper feed means for feeding paper to the conveyor belt 21 and a paper discharge means for discharging paper on which an image is formed by liquid ejected from the recording head 11 as an image forming means.

In this image forming device configured in this way, the fed paper is transported intermittently by the transport belt 21, and the recording head 11 is driven in response to an image signal while the carriage 4 is moving in the main scanning direction, ejecting droplets onto the stationary paper to record one line, and after transporting the paper a specified distance, the next line is recorded. This operation is repeated to form an image on the paper, and the paper is then discharged after the image has been formed.

Next, the carriage portion of this image forming device will be described in detail. Figure 3 is a perspective view of the main part of the carriage portion of the image forming device, and Figure 4 is a side view of the carriage portion.

The carriage 4 is provided with a carriage cover 42 that covers the top of the head mounting section 41, which mounts the recording head 11, and a sensor attachment section 43 that is integral with the carriage cover 42 and extends from the head mounting section 41 along the paper feed direction.

A head-side board 112 that mounts the head-side electrical components is attached to the underside of the sensor mounting portion 43, an encoder sensor 16 is provided on the head-side board 112, and the encoder scale 15 is disposed in a position that can be read by the encoder sensor 16.

Guide member 3, which is a guide member that guides carriage 4 in a slidable manner, is made of a sheet metal member and has guide surfaces 301, 302, and 303 that serve as support surfaces for slidably guiding carriage 4. The head mounting portion 41 of carriage 4 has a sliding portion 411 that slidably contacts guide surface 301 of guide member 3, a sliding portion 402 that slides against guide surface 302, and a sliding portion (slider) 409 that slides against guide surface 303. In this case, guide surface 301 of guide member 3 is a surface that determines the height position of carriage 4, guide surface 302 is a surface (rotation stopper) that receives the moment due to the carriage 4's own weight, and guide surface 303 is a surface that determines the position of carriage 4 in the sub-scanning direction.

The guide member 3 is disposed over the entire area in the main scanning direction and also serves as a partition member that separates the head mounting portion 41 of the carriage 4 from the sensor mounting portion 43 and the encoder scale 15.

In addition, a front stay 61 that abuts against the guide member 3 is disposed below the sensor mounting portion 43 of the carriage 4.

The carriage cover 42 of the carriage 4 has a recess 50 between the head mounting section 41 and the section that will become the sensor mounting section 43. The cover 101 has a partition member 51 that fits into the recess 50 of the carriage cover 42 and separates the head mounting section 41 and the sensor mounting section 43 on the upper side of the carriage 4. The partition member 51 is disposed over the entire area in the main scanning direction.

This separates the head mounting section 41 and the sensor mounting section 43 from each other even above the carriage 4, and the recess 50 and the partition member 51 that fits into it can almost completely block the space between the head mounting section 41 and the sensor mounting section 43.

On the other hand, a pressure plate 71 having a pressure roller 72 at its tip that presses the paper against the conveyor belt 21 is disposed on the rear stay 62 between the carriage 4 and the conveyor belt 21, and a paper discharge guide 73 that guides the paper discharged from the conveyor belt 21 is disposed below the guide member 3.

In the example shown in FIG. 4, the carriage 4 has a head mounting portion 41 on which the recording head 11 is mounted, and a sensor mounting portion 43 on which at least the encoder sensor 16 is mounted, the sensor mounting portion 43 is provided extending from the head mounting portion 41, and the encoder scale 15 is disposed in a position where it can be read by the encoder sensor 16 attached to the sensor mounting portion 43.

Note that Figures 1 to 4 show an example of a device that ejects liquid, but the device is not limited to this and may be, for example, a garment printer that prints by attaching fabric to a table called a platen.

5 is a schematic diagram illustrating an example of an encoder scale 15. The encoder scale 15 has, for example, an array of uniform white and black lines.
4, the encoder sensor 16 is disposed so as to straddle the encoder scale 15 and reads the encoder scale 15. The encoder sensor 16 is made up of a light-emitting section and a light-receiving section, and when it passes through the arrangement of white and black marks on the encoder scale 15, it detects the position of the carriage 4 from the distance between the black marks. The image forming apparatus controls the timing of ejecting liquid from the recording head 11 based on the detected position.

In an inkjet printer, satellites, ink mist, and the like adhere to the encoder scale 15 near the nozzles, and accumulate on the surface of the encoder scale 15 over a long period of use, causing dirt on the surface of the encoder scale 15. As a result, the encoder sensor 16 generates reading errors due to such dirt. Therefore, it is important to clean dirt from the encoder scale 15.
An encoder cleaning tool according to one embodiment will be described in detail below.

Embodiment 1.
Figure 6 is a schematic diagram illustrating an example of an encoder cleaning tool of embodiment 1, where (A) is a diagram showing an example of an encoder cleaning tool, (B) is a diagram showing the encoder cleaning tool sandwiched between an encoder scale, and (C) is a diagram showing another example of an encoder cleaning tool.
The encoder cleaning tool 200 is a tool for cleaning an encoder scale 15 provided in a device that ejects liquid, and includes at least a cleaning member 210 .
The cleaning member 210 is a member that sandwiches the encoder scale 15 and comes into contact with both sides of the sandwiched encoder scale 15 to clean the encoder scale 15 .

As shown in FIG. 6(B), the encoder cleaning tool 200 cleans by sandwiching the encoder scale 15 between two cleaning members 210 and moving in contact with the surface of the encoder scale 15. FIG. 6(B) is a view of the cleaning members 210 as seen from below. Cleaning of the encoder scale is performed by moving at least one of the cleaning members 210 and the encoder scale 15.

The two cleaning members 210 are preferably arranged opposite each other with the encoder scale 15 in between. In this way, it is possible to suppress bias in the force applied to both sides of the encoder scale 15 during cleaning. This makes it possible to prevent the encoder scale 15 from stretching in one direction and the encoder scale from becoming distorted.

The cleaning member 210 is preferably made of a material that can be impregnated with a cleaning liquid, which can improve the effect of wiping off dirt on the surface of the encoder scale 15.
The cleaning member 210 is preferably made of any one of nonwoven fabric, fiber, and foam material, which can easily absorb the cleaning liquid.
For example, the cleaning member 210 can wipe off dirt on the surface of the encoder scale 15 by wrapping a nonwoven fabric or a cloth woven with ultrafine fibers as a member that comes into contact with the surface of the encoder scale 15. Also, a foam material or the like may be impregnated with a cleaning liquid, such as alcohol or a surfactant, that removes dirt from the surface of the encoder scale 15. Furthermore, after wiping off the dirt with a cleaning agent, it is desirable to dry wipe the surface with another cleaning member.

The cleaning member 210 is not limited to a cylindrical shape as shown in FIG. 6(A) and may be, for example, a polygonal prism. As another example of a shape, FIG. 6(C) shows an encoder cleaning tool 200a having a square prism-shaped cleaning member 210a.

The encoder cleaning tool described above can be used, for example, (1) directly by a user or (2) mounted on a carriage to clean the encoder scale 15. This will be described in detail in each of the following embodiments.

Embodiment 2.
In the second embodiment, a case where a user uses an encoder cleaning tool will be described.
FIG. 7 is a schematic diagram illustrating an example of an encoder cleaning tool according to the second embodiment.
The encoder cleaning tools 200b to 210e are examples in which handles 220b to 220e are provided on the cleaning member 210 shown in FIG. 6(A).
The encoder cleaners 200b to 200e are formed so that the two cleaning members 210 can be opened and closed by a user operating (pushing or pinching, etc.) the handles 220b to 220d with his or her fingers, thereby sandwiching the encoder scale 15 therebetween.

In Fig. 7, (A) and (B) show different shapes of the part pressed with the finger. In (A), the handle 220b is ring-shaped to make it easier to press, and in (B), the handle 220c pressed with the finger is plate-shaped to reduce manufacturing costs. The ends of the handles 220b and 220c are attached to the two cleaning members 210, and the two cleaning members 210 can be opened and closed using hinges and springs. Also, (C) is a simple example in which the handle 220d is made of wire. In (D), the position of the spring 222e has been changed so that it is normally closed, and when the user presses the handle 220e, the cleaning members 210 expand from the hinge 221e to sandwich the encoder scale 15.

To use the encoder cleaners, for example, the user operates the handles 220b to 220e, spreads the two cleaning members 210 apart, sandwiches the encoder scale 15, brings the cleaning members 210 into contact with the encoder scale 15, and moves the encoder cleaners 200b to 200d left and right to clean.

A cylindrical foam material or the like can be used as the material for the cleaning member 210. Fig. 7(E) is a cross-sectional view for explaining an example of a cleaning member 210f using a cylindrical foam material, and shows an example of a cross section taken along line VII-VII when a cylindrical foam material is used for the cleaning member 210 of the encoder cleaning tool 200b shown in Fig. 7(A).
In Fig. 7E, the cleaning member 210f is in the shape of a roller. Specifically, the cleaning member 210 is formed so that the core material 211 is cylindrical and the foam material 212 rotates around the handle. The movement can be made smoother by using a bearing.

In such a case, it is more effective to operate the encoder cleaning tool 200f so that friction occurs by shifting the speed at which the encoder cleaning tool 200f moves along the encoder scale 15 (along the main scanning direction) from the surface speed of the foam material 212 (the speed at which the foam material 212 rotates). For example, it is preferable that the rotation speed of the foam material 212 of the cleaning member 210f is slower than the speed at which the cleaning member 210f of the encoder cleaning tool 200 moves along the encoder scale 15.
A means for providing a speed difference between the encoder cleaning tool 200f and the encoder scale 15 may be one that generates more friction between the encoder cleaning tool 200f and the encoder scale 15. For example, the material of the cleaning member 210f that clamps the encoder scale 15 may be changed, or the pressure with which the encoder scale 15 is clamped may be increased.

Embodiment 3.
In the third embodiment, a case will be described in which an encoder cleaner is mounted on a carriage of a device (image forming device) that ejects liquid.
Figure 8 is a diagram illustrating an example of an encoder cleaning tool of embodiment 3, where (A) is a schematic diagram illustrating an example of an encoder cleaning tool, (B) is a diagram illustrating the position at which the encoder cleaning tool is attached to the carriage, (C) is a schematic diagram viewed from the arrow C shown in (B) when the encoder cleaning tool is attached to the carriage, and (D) is a schematic diagram viewed from the arrow D of (C).
The encoder cleaner 200g has a cleaning member 210g and a handle portion 220g.
Cleaning member 210g may be in the form of any of cleaning members 210, 210b or 210f previously described.
The handle 220g is formed to be able to open and close the cleaning member 210g, and is provided with, for example, a hinge 221g and a spring 222g. In Fig. 7A, an example of the positions where the hinge 221 and the spring 222 are provided is shown by dotted lines. The handle 220g also has a hook 223 that allows it to be attached to and detached from the carriage.

As shown in Figures 8(B) to (D), the carriage 4 is provided with an engagement portion 310 on the sensor mounting portion 43 where the encoder sensor 16 is provided. In Figure 8(B), the position where the encoder sensor 16 is provided is indicated by a dotted line. Figure 8(C) shows a part of the configuration when viewed from the opposite side to the side shown in Figure 4. Figure 8(D) shows the encoder scale 15, the encoder sensor 16, the cleaning member 210g, and the guide member 3, and omits other configuration.
The engaging portion 310 has a shape that allows the encoder cleaning tool 200g to be detachably attached by the hook 223, for example, a hole for hanging the hook 223. In addition, the engaging portion 310 has a shape that allows the encoder cleaning tool 200g to be held (stable so as not to fall off) with the cleaning member 210g sandwiching and in contact with the encoder scale 15. In this way, when a user opens and closes the handle portion 220g so that the cleaning member 210g sandwiches the encoder scale 15, hangs the hook 223 on the engaging portion 310, and attaches the encoder cleaning tool 200g to the carriage 4, the carriage 4 moves in the main scanning direction, whereby the encoder scale 15 can be cleaned.

Furthermore, as shown in FIG. 7E, if the cleaning member 210g is made of a foam material and has a roller shape, cleaning efficiency can be improved.
The engaging portion 310 may be, for example, a hole in an ink supply tube provided in the carriage 4 .

FIG. 9 is a schematic diagram illustrating another example of the encoder cleaning tool according to the third embodiment.
The encoder cleaning tool 200 shown in Fig. 9(A) has two cleaning members 210h and a holding portion 230. Fig. 9(A) shows a side surface of the encoder cleaning tool 200h, specifically, the side where the encoder scale 15 is sandwiched between the two cleaning members 210h.
7(E), the cleaning member 210h has a roller shape, has a shaft 213 as a core, and is provided with a cylindrical foam material around the shaft 213. The shaft 213 is longer than the end of the foam material.

The holding portion 230 has a first side surface 231, a second side surface 232, and a bottom portion 233. The first side surface 231 and the bottom portion 233 are provided with an attachment portion (not shown) into which the shaft 213 of one cleaning member 210h is fitted. The second side surface 232 and the bottom portion 233 are provided with an attachment portion into which the shaft 213 of the other cleaning member 210 is fitted. The shaft 213 and the attachment portion have a detachable fitting mechanism.
The first side surface 231 and the second side surface 232 of the holding portion 230 are formed so as to be detachably fixed to the carriage 4. For example, the first side surface 231 and the second side surface 232 are joined to the bottom portion 233 by hinges 241, 242 and are provided so as to be movable (for example, the movement of arrows M1, M2). In addition, the movement allows the cleaning member 210h to be replaced.

The carriage 4 and the encoder cleaning tool 200h are fixed to each other by, for example, extending an upper portion of the second side surface 232 to the surface of the carriage 4 and fixing the cleaning member 210h to the carriage 4. In this manner, the encoder cleaning tool 200h can be driven together with the carriage 4 by the motor that drives the carriage 4.
The bottom portion 233 has two recesses 234 at the bottom, and is placed on a guide rod (such as the guide member 3 as a guide member). This stabilizes the encoder cleaning tool 200h. In addition, it is preferable that the cleaning member 210h and the holding portion 230 are structured so as to be separable as a unit.

The cleaning member 210h clamps and fixes the encoder scale 15 from above.
The cleaning member 210h can change the frictional force by changing the ease of rotation at the joint between the shaft 213 and the first and second sides 231 and 232. For example, the frictional force can be changed by changing the materials of the cleaning member 210 and the shaft 213.

The encoder cleaning tool 200i shown in FIG. 9(B) is a modified version of the encoder cleaning tool 200h, with one recess 234 facing the front side of the image forming device. When attaching the encoder cleaning tool 200i, the one recess 234 is butted against the guide rod on the front side from the center, and then placed on the guide rod on the rear side. Either method has the effect of making it easier to clean the encoder.

Embodiment 4.
In the fourth embodiment, the relationship between the frictional force caused by the pressing of the cleaning member and the elastic force of the spring of the encoder scale will be described.
FIG. 10 is a diagram illustrating the relationship between the frictional force caused by the pressing of the cleaning member and the elastic force of the spring of the encoder scale.
Because the encoder scale 15 is in the form of a thin film, one end of the encoder scale 15 is connected to the nearest frame by a spring, which pulls the encoder scale. For example, as shown in Fig. 10(A) as a schematic, the encoder scale 15 is joined to an apparatus housing frame 18 (for example, the main side plate 1A in Fig. 2) via a leaf spring 17. Fig. 10(B) shows an example of a state in which a leaf spring is inserted into a hole provided at the end of the encoder scale 15. In Fig. 10(B), the encoder scale 15 is indicated by a dotted line.
In this way, the encoder scale is joined to the device housing frame via the spring, so if the friction of the cleaning member is stronger than the tension of the spring, the encoder scale will be pulled and distorted.
If the length of expansion and contraction of the spring is x (m) and the magnitude of the spring's elastic force is F (N), it can be expressed by the following equation 1 (k is an arbitrary coefficient, m is meters, and N is Newtons).
F = k x (Equation 1)

In addition, when cleaning the encoder scale 15, the frictional force (R) generated when the cleaning member clamps the encoder scale 15 is as shown in Figure 10 (C) where the normal force is N and the frictional force is R, and can be expressed by the following equation 2.
|Rmax| = μ·N (Equation 2)
Here, |Rmax| represents the absolute value of the maximum value (Rmax) of the friction force R.
When cleaning the encoder scale 15, if the frictional force exceeds the elastic force, the encoder scale 15 will become loose. It would be good if the scale could be restored by a spring, but this is undesirable as there is a possibility that the scale may come off the frame. Therefore, it is important that the frictional force caused by the pressure of the cleaning member is weaker than the elastic force of the encoder spring.

Other embodiments.
In each of the above embodiments, the embodiment in which the encoder scale 15 is sandwiched between two cleaning members has been described, but the present invention is not limited to this. For example, a single cleaning member may be used. Fig. 11 is a schematic diagram illustrating another shape of the cleaning member. The cleaning member 210j of the encoder cleaner 200j is provided with a notch (recess, groove) 214 that sandwiches the encoder scale 15. The notch 214 sandwiches the encoder scale 15, and the side surfaces of the notch 214 come into contact with both sides of the encoder scale to clean the surface of the encoder scale 15.

As described above, according to each of the above embodiments, by wiping the encoder from the left end to the right end in a simple manner, the surface of the encoder scale can always be kept clean and errors in reading the encoder sensor can be prevented.
Furthermore, for example, the technology of Patent Document 1 is costly, but the encoder cleaning tool of one embodiment can reduce costs.
The encoder cleaning tool of each of the above embodiments is effective in the following cases, for example. There are many kinds of fabrics used in garment printers, such as cotton and polyester. These have large surface irregularities, unlike inkjet printers that use conventional paper. Furthermore, depending on the fabric, the user needs to widen the gap between the carriage and the fabric, as wrinkles and fuzz may appear on the surface. If the gap is widened, the distance from when the ink is discharged from the nozzle to when it lands on the fabric increases, making the discharge unstable. This is likely to cause problems such as satellites where ink droplets separate, ink droplets scattering in a mist, and deflected discharge. The satellites and ink mist become mist and float inside the device, adhering to components inside the printer and becoming stains. In addition, if the gap between the carriage and the fabric is widened, the ink mist increases, the encoder becomes more stained than expected, and an error occurs in the encoder skipping. In order to reduce this staining as much as possible, the encoder scale can be cleaned periodically using the encoder cleaning tool of each of the above embodiments, thereby suppressing the occurrence of errors caused by the encoder sensor.
By using the encoder cleaning tool of each of the above embodiments to hold both sides of the encoder scale and wipe it from the left end to the right end, the surface of the encoder scale can always be kept clean and sensor skipping errors can be prevented.

Next, an example of a device for discharging liquid according to the present invention will be described with reference to Figures 12 and 13. Figure 12 is a plan view of the main parts of the device, and Figure 13 is a side view of the main parts of the device.

This device is a serial type device, and the carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B to movably hold the carriage 403. The carriage 403 is then moved back and forth in the main scanning direction by the main scanning motor 405 via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

This carriage 403 is equipped with a liquid ejection unit 440 that integrates a liquid ejection head 404 according to the present invention and a head tank 441. The liquid ejection head 404 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 404 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

The head tank 441 is supplied with liquid stored in the liquid cartridge 450 by a supply mechanism 494 for supplying liquid stored outside the liquid ejection head 404 to the liquid ejection head 404.

The supply mechanism 494 is composed of a cartridge holder 451, which is a filling section in which the liquid cartridge 450 is attached, a tube 456, a liquid delivery unit 452 including a liquid delivery pump, and the like. The liquid cartridge 450 is detachably attached to the cartridge holder 451. Liquid is delivered from the liquid cartridge 450 to the head tank 441 by the liquid delivery unit 452 via the tube 456.

This device is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

The conveyor belt 412 attracts the paper 410 and conveys it to a position facing the liquid ejection head 404. The conveyor belt 412 is an endless belt that is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction.

The conveyor belt 412 moves in a circular motion in the sub-scanning direction as the conveyor roller 413 is rotated and driven by the sub-scanning motor 416 via the timing belt 417 and timing pulley 418.

Furthermore, a maintenance and recovery mechanism 420 that maintains and recovers the liquid ejection head 404 is arranged on one side of the carriage 403 in the main scanning direction, beside the conveyor belt 412.

The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzles are formed) of the liquid ejection head 404, and a wiper member 422 that wipes the nozzle surface.

The main scanning movement mechanism 493, the supply mechanism 494, the maintenance recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A, 491B, and a back plate 491C.

In this device configured in this manner, the paper 410 is fed onto the conveyor belt 412 and adsorbed thereon, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412.

Then, by moving the carriage 403 in the main scanning direction while driving the liquid ejection head 404 in response to an image signal, liquid is ejected onto the stationary paper 410 to form an image.

As such, this device is equipped with a liquid ejection head according to the present invention, and is therefore capable of stably forming high-quality images.

Next, an example of a liquid ejection unit according to the present invention will be described with reference to FIG. 14. FIG. 14 is a plan view of the main parts of the unit.

This liquid ejection unit is composed of the components that make up the device that ejects the liquid, including a housing portion made up of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid ejection head 404.

It is also possible to configure a liquid ejection unit by further attaching at least one of the aforementioned maintenance and recovery mechanism 420 and supply mechanism 494 to, for example, the side plate 491B of this liquid ejection unit.

Next, another example of a liquid ejection unit according to the present invention will be described with reference to FIG. 15. FIG. 15 is a front view of the unit.

This liquid ejection unit is composed of a liquid ejection head 404 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 is provided on the upper part of the flow path part 444 to electrically connect to the liquid ejection head 404.

In this application, a "liquid ejection device" is a device that includes a liquid ejection head or a liquid ejection unit, and ejects liquid by driving the liquid ejection head. A 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.

This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

For example, examples of "devices that eject liquid" include image forming devices that eject ink to form an image on paper, and three-dimensional modeling devices that eject modeling liquid onto a powder layer formed by layering powder to form a three-dimensional object.

In addition, a "liquid ejecting device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

The above "object to which liquid can adhere" means an object to which liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects to which liquid can adhere.

The above-mentioned "materials to which liquid can adhere" include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, and textiles for clothing, as long as the liquid can adhere even temporarily.

"Liquid" also includes ink, processing liquid, DNA samples, resist, pattern materials, binders, modeling liquids, or solutions and dispersions containing amino acids, proteins, and calcium.

In addition, the "liquid ejection device" may be a device in which a liquid ejection head and an object to which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which the liquid ejection head moves, and a line type device in which the liquid ejection head does not move.

Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle to granulate the raw material into fine particles.

A "liquid ejection unit" is a collection of components related to ejecting liquid, integrating functional parts and mechanisms with a liquid ejection head. For example, a "liquid ejection unit" includes a combination of at least one of the following components with a liquid ejection head: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism.

Here, integration includes, for example, the liquid ejection head, functional parts, and mechanism being fixed to each other by fastening, bonding, engagement, etc., and one being held movably relative to the other. The liquid ejection head, functional parts, and mechanism may also be configured to be detachable from each other.

For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, such as liquid ejection unit 440 shown in FIG. 13. Others have a liquid ejection head and a head tank integrated together, connected together by a tube or the like. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

There are also liquid ejection units in which the liquid ejection head and carriage are integrated.

In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, as shown in FIG. 14, the liquid ejection head, carriage, and main scanning movement mechanism are integrated together.

In some liquid ejection units, 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, integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

As shown in Figure 15, there is also a liquid ejection unit in which a tube is connected to a liquid ejection head to which a head tank or flow path components are attached, and the liquid ejection head and the supply mechanism are integrated.

The main scanning movement mechanism includes the guide member alone. The supply mechanism also includes the tube alone and the loading section alone.

The "liquid ejection head" is not limited in the pressure generating means used. For example, in addition to the piezoelectric actuator (which may use a laminated piezoelectric element) as described in the above embodiment, it may also use a thermal actuator that uses an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a vibration plate and an opposing electrode.

In addition, in this application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

15 Encoder scale 16 Encoder sensors 200, 200a to 200j Encoder cleaner 210, 210b, 210g Cleaning member 211 Core 212 Foam material 213 Shaft 214 Notches 220b to 220e, 220g Handle portion 221 Hinge 222 Spring 223 Hook 230 Holding portion

JP 2012-143979 A

Claims (6)

An inkjet head;
a carriage that drives the inkjet head along a guide member;
An encoder scale disposed along the guide member;
an encoder cleaning tool having cleaning members that sandwich the encoder scale and contact and clean both sides of the encoder scale ,
The encoder cleaning tool is detachable from the carriage,
The encoder scale is fixed to a device that ejects liquid by a spring at both ends in a longitudinal direction,
The cleaning is performed so that the frictional force between the encoder cleaning tool and the encoder scale during cleaning is smaller than the elastic force of the spring.
A liquid ejection device comprising: 2. The liquid ejecting device according to claim 1, wherein the cleaning member is made of a material capable of impregnating with a cleaning liquid. 3. The liquid ejecting device according to claim 1, wherein the cleaning member is made of any one of a nonwoven fabric, a fiber, and a foam material. 4. The liquid ejecting device according to claim 1, wherein the cleaning member is in the form of a roller. The encoder scale is sandwiched between the cleaning members, and the speed A of the cleaning members moving along the encoder scale is faster than
5. The liquid ejecting device according to claim 4, wherein the rotation speed B of the roller-shaped cleaning member is slow. With the encoder cleaning tool attached to the carriage, the encoder cleaning tool holds the encoder scale,
6. The liquid ejection device according to claim 1, wherein the encoder scale is cleaned by driving the carriage along the guide member.

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