Patent Grant
8955966
The present application claims priority from Japanese Patent Application No. 2013-040077, filed on Feb. 28, 2013, the disclosure of which is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a recording apparatus recording an image.
2. Description of the Related Art
There is known a roller pair which performs registration of a recording medium such as a sheet material by making the recording medium along a guide surface as a reference wall. The roller pair includes a transport roller and an skew roller. A rotational shaft of the transport roller is perpendicular to the guide surface, and the transport roller transports the recording medium in a transport direction. The skew roller has an outer circumferential surface in a columnar shape. The skew roller rotates in association with the transport of the recording medium and has a rotational shaft which is inclined with respect to the rotational shaft of the transport roller so that the recording medium can be drawn to the side of the guide surface. This construction enables the registration of the recording medium.
There is also known an skew roller pair with a spur which performs the registration of the recording medium by making the recording medium along the guide surface. The spur is used for the skew roller pair with the spur, instead of the skew roller forming the above roller pair.
In the registration of the recording medium, the roller pair causes the skew roller to move the recording medium to the guide surface, even when the end surface of the recording medium is brought into contact with the guide surface. In this situation, although the thrust load is applied on the skew roller owing to the contact between the guide surface and the recording medium, the recording medium is easy to slide on the skew roller, in other words, the recording medium is more likely to move in a direction away from the guide surface. Thus, occurrence of a jam of the recording medium can be suppressed. However, the skew roller scrapes an image recorded on the recording medium when the recording medium slides on the skew roller, and thus any image defect problem may occur. Further, in the case that the image recorded on the recording medium makes contact with the skew roller, a recording material for forming the image is adhered to the outer circumferential surface of the skew roller, which may cause a problem that the recording material adhered to the skew roller is transferred to the recording medium to make the recording medium dirty.
Meanwhile, in the case that the spur is used instead of the skew roller as described above, since the spur has teeth each having a very small contact area with the recording medium as compared with the skew roller, it is possible to prevent the recording medium from getting dirty. However, the teeth of the spur function as spikes to stick in the surface of the recording medium in the registration of the recording medium. Thus, even when the thrust load is applied on the spur due to the contact between the guide surface and the end surface of the recording medium, the recording medium hardly slides on the spur. As a result, the jam of the recording medium may occur.
An object of the present teaching is to provide a recording apparatus which is capable of suppressing occurrence of a jam of a recording medium and dirt in the recording medium.
According to an aspect of the present teaching, there is provided a recording apparatus configured to discharge a liquid to a recording medium to perform recording thereon, including: a recording section configured to discharge the liquid; and a transport mechanism configured to transport the recording medium for which an image is recorded by the liquid discharged from the recording section.
The transport mechanism includes:
a guide surface extending linearly and configured to guide one of both side ends of the recording medium transported;
a driving roller configured to make contact with a surface, of the recording medium, on which no image is recorded and transport the recording medium; and
a driven spur configured to make contact with a surface, of the recording medium, on which the image is recorded so that the recording medium is nipped between the driven spur and the driving roller, and including at least one spur which is configured to rotate in association with the transport of the recording medium by rotation of the driving roller.
Each of the at least one spur includes a plurality of teeth protruding in a first direction, which is perpendicular to an axis of a rotational shaft of the driven spur as viewed from a direction of the axis, and aligned and arranged in a circumferential direction with the axis of the driven spur as a center. Each of the teeth includes two side surfaces and a front end surface, each of the two side surfaces inclining to come closer to an imaginary line perpendicular to the axis at positions, which are disposed nearer to a tooth tip of each of the teeth from a base of each of the teeth, as viewed from the direction of the axis, the front end surface being formed at a position closer to the axis than a line of intersection of two imaginary planes extending along the two side surfaces. In a graph, in which a length X (mm) of the front end surface in a second direction, which is an in-plane direction of the front end surface and is perpendicular to both of the direction of the axis and the first direction, is a horizontal axis and an angle Y (degree) between the axis and the imaginary line perpendicular to the guide surface passing through a point of intersection between the axis and the guide surface is a vertical direction, the length X of the front end surface of the driven spur and the angle Y of the driven spur are configured to be within a first area surrounded by mathematical expressions 1 to 6 described below.
The mathematical expression 1 is “X>0”, the mathematical expression 2 is “Y>0”, the mathematical expression 3 is “Y=40.1X+1.6”, the mathematical expression 4 is “Y=−9.0X+5.6”, the mathematical expression 5 is “Y=−12.1X+6.0”, and the mathematical expression 6 is “Y=−14.7X+7.1”.
In the above construction, the driven spur includes at least one spur having the teeth, each of which has the front end surface, and the length X of the front end surface of the driven spur and the angle Y of the driven spur are configured to be within the first area, even when the driven spur is inclined so that the recording medium is drawn to the guide surface. The mathematical expressions 3 to 6 are obtained by transporting different types of first to fourth recording mediums under a predetermined environment and evaluating transport results. The mathematical expression 3 is an expression representing a boundary between a range in which no jam occurs in the transported recording medium and a range in which the jam occurs in the transported recording medium. The mathematical expressions 4 to 6 are expressions each representing a boundary between a range in which the liquid is less likely to be transferred to the transported recording medium by the driven spur and a range in which the liquid is transferred to the transported recording medium by the driven spur. Therefore, it is possible to suppress occurrence of both the jam of the recording medium and the dirt on the recording medium at the time of transporting the recording medium.
The recording apparatus of the present teaching is configured such that the driven spur includes at least one spur having the teeth, each of which has the front end surface, and that the length X of the front end surface of the driven spur and the angle Y of the driven spur are within the first area, even when the driven spur is inclined so that the recording medium is drawn to the guide surface. Therefore, it is possible to suppress the occurrence of both the jam of the recording medium and the dirt on the recording medium at the time of transporting the recording medium.
Hereinbelow, an embodiment of the present teaching will be described below while referring to the accompanying drawings.
At first, an explanation will be made about an overall construction of an ink-jet printer 1 as an embodiment of a recording apparatus according to the present teaching with reference to
The printer 1 includes a casing 1a in a rectangular parallelepiped shape. A paper discharge section 4 is provided at an upper portion of a ceiling plate of the casing 1a. The internal space of the casing 1a can be divided into spaces A, B in this order from the top. Those formed in the spaces A, B are a paper transport path which is directed from a paper feed section 23 to the paper discharge section 4 and a paper refeed path which is directed from a downstream side to an upstream side of the paper transport path. As shown in
In the space A, a head 2 discharging a black ink, a transport unit 3, a controller 100, and the like are arranged. The head 2 is an example of a recording section of the present teaching. Further, an unillustrated ink cartridge is installed in the space A. The black ink is stored in the cartridge. The cartridge is connected to the head 2 via an unillustrated tube and an unillustrated pump and the ink is supplied to the head 2.
The head 2 is a line-type head having a substantially rectangular parallelepiped shape elongated in a main scanning direction. Many discharge ports are open on the lower surface of the head 2, and thereby defining a discharge surface 2a. In a case that recording is performed, the black ink is discharged from the discharge surface 2a. The head 2 is supported by the casing 1a by the aid of a head holder 2b. The head holder 2b holds the head 2 so that a predetermined gap, which is suitable for the recording, is formed between the discharge surface 2a and a platen 3d which will be described later.
The transport unit 3 includes an upstream guide section 3a, a downstream guide section 3b, a refeed guide section 3c, and the platen 3d. The platen 3d is arranged at a position opposed to the discharge surface 2a of the head 2. The platen 3d has a flat upper surface. The platen 3d supports the paper P from below and constitutes a recording area, which is a part of the paper transport path, between the discharge surface 2a and the platen 3d. The upstream guide section 3a and the downstream guide section 3b are arranged with the platen 3d intervening therebetween. The upstream guide section 3a includes two guides 31, 32 and two transport roller pairs 41, 42. The upstream guide section 3a connects the recording area positioned between the platen 3d and the head 2 with the paper feed section 23. The downstream guide section 3b includes two guides 33, 34 and three transport roller pairs 43 to 45 and connects the recording area with the paper discharge section 4. The paper transport path is defined by the four guides 31 to 34, the platen 3d, and the head 2.
The refeed guide section 3c, which is an example of a transport mechanism of the present teaching, includes three guides 35 to 37, three transport roller pairs 46 to 48, and a positioning mechanism 50, and the refeed guide section 3c connects the upstream guide section 3a and the downstream guide section 3b while making a detour to avoid the recording area. The guide 35 is connected to an intermediate portion of the guide 33, and the guide 35 connects the refeed guide section 3c with the downstream guide section 3b. The guide 37 is connected to an intermediate portion of the guide 31, and the guide 37 connects the refeed guide section 3c with the upstream guide section 3a. The paper refeed path is defined by the three guides 35 to 37 and the positioning mechanism 50.
In the transport roller pair 44, the transport direction of the paper P is switched in accordance with the control of the controller 100. In other words, the transport roller pair 44 rotates so that the paper P is transported upwardly in a case that the paper P is transported from the recording area to the paper discharge section 4. On the other hand, in a case that the paper P is transported from the paper transport path to the paper refeed path, the direction of rotation of the transport roller pair 44 is switched as follows. That is, in a case that the backward end of the paper P is positioned between the transport roller pair 44 and a portion connecting the guide 33 with the guide 35 and that the backward end of the paper P is detected or sensed by a paper sensor 27, the paper P is transported downwardly such that the backward end of the paper P detected by the paper sensor 27 is positioned as the forward end. The paper P, which is transported from the paper transport path to the paper refeed path, is refed to the upstream guide section 3a. In this situation, the paper P, which is subjected to the refeeding, is transported again to the recording area in a state that the paper P is turned upside down as compared with when the paper P passed through the recording area just before. Accordingly, it is possible to record images on the both surfaces of the paper P.
The three transport roller pairs 46 to 48 are arranged in this order, and the positioning mechanism 50 is arranged between the transport roller pairs 47, 48. Further, the positioning mechanism 50 is arranged between the recording area and the paper feed section 23 in a vertical direction, that is, between the platen 3d and the paper feed section 23. The positioning mechanism 50 includes an upper guide 51, a lower guide 52, a driving roller 61, and a driven spur 71. The positioning mechanism 50 transports the paper P while allowing one end in a width direction of the paper P transported to the space between the both guides 51, 52 to abut against a guide surface 54a, and thereby positioning the paper P in the width direction. Details of the positioning mechanism 50 will be described later. The width direction of the paper P is the main scanning direction, which is a direction perpendicular to a transport direction E of the paper P.
The paper feed section 23 is arranged in the space B. The paper feed section 23 includes a paper feed tray 24 and a paper feed roller 25. The paper feed tray 24 is installable/removable with respect to the casing 1a. The paper feed tray 24 is a box which is open upwardly, and the paper feed tray 24 can accommodate a plurality of pieces of paper P. The paper feed roller 25 feeds the paper P disposed at the upper most position in the paper feed tray 24.
A subsidiary scanning direction is a direction parallel to a paper transport direction D in which the paper P is transported by the transport roller pairs 42, 43 and the paper transport direction E in which the paper P is transported by the transport roller pairs 47, 48. The main scanning direction is a direction parallel to the horizontal plane and perpendicular to the subsidiary scanning direction.
Next, the controller 100 will be explained. The controller 100 controls the operation of respective components of the printer 1, and the controller 100 manages the operation of the entire printer 1. The controller 100 controls a recording operation on the basis of a recording command supplied from any external apparatus such as a PC connected to the printer 1. Specifically, the controller 100 controls, for example, a transport operation for the paper P and an ink discharge operation in synchronization with the transport of the paper P.
For example, in a case that a recording command to perform the recording on one side of the paper P is received from the external apparatus, the controller 100 drives the paper feed section 23 and the transport roller pairs 41 to 45 based on this recording command. The paper P, which is fed from the paper feed tray 24, is guided by the upstream guide section 3a, and the paper P is fed to the recording area, that is, a space between the platen 3d and the head 2. When the paper P passes just under the head 2, the head 2 is controlled by the controller 100 and ink droplets are discharged from the head 2. Accordingly, a desired image is recorded on the surface of the paper P. The ink discharge operation such as ink discharge timing is based on a detection signal supplied from a paper sensor 26. The paper sensor 26 is arranged upstream of the head 2 in the transport direction, and the paper sensor 26 detects the forward end of the paper P. The paper P, on which the image has been recorded, is guided by the downstream guide section 3b, and the paper P is discharged from the upper portion of the casing 1a to the paper discharge section 4.
For example, in a case that a recording command to perform the recording on both sides of the paper P is received from the external apparatus, the controller 100 drives the paper feed section 23 and the transport roller pairs 41 to 45 on the basis of this recording command. At first, an image is formed on the surface of the paper P in the same manner as the single-sided recording, and the paper P is transported toward the paper discharge section 4. As shown in
Next, the positioning mechanism 50 will be explained in detail with reference to
The driving roller 61 and the driven spur 71 facing the driving roller 61 are arranged at a position closer, in the main scanning direction, to the guide surface 54a from the center of the transport path between the upper guide 51 and the lower guide 52. The center of the transport path is depicted by alternate long and short dash lines in
As shown in
Further, as shown in
As shown in
As shown in
As shown in
The four areas U1K, U2K, U3K, and U4K and the overlapped area U5K in which the four areas U1K, U2K, U3K, and U4K are overlapped with each other will be explained below while referring to
The mathematical expression 1 is “X>0”, the mathematical expression 2 is “Y>0”, the mathematical expression 3 is “Y=47.5X+1.7”, and the mathematical expression 4 is “Y=−14.7X+7.1”.
TABLE 1 given below shows presence or absence of occurrence of jam and dirt in a first paper (BP60PA, produced by Brother Industries, Ltd.) in a case that an image having a predetermined pattern is recorded on the first paper and the first paper is refed to the positioning mechanism 50 under various conditions of the length X of the front end surface 77 of each tooth 72a of the driven spur 71 and the angle Y of the driven spur 71. Noted that the length X of the front end surface 77 is changed by removing the tip of each tooth of a spur, which has a diameter of 6 mm and teeth each having the sharp tooth tip, at positions directed toward the center of the spur from the tip of each tooth. That is, in a case that the tip of each tooth is removed at a position located 0 mm from the tip of each tooth, the length X of the front end surface 77 is 0 mm; that the tip of each tooth is removed at a position located 0.05 mm from the tip of each tooth, the length X of the front end surface 77 is 0.04 mm; that the tip of each tooth is removed at a position located 0.1 mm from the tip of each tooth, the length X of the front end surface 77 is 0.07 mm; that the tip of each tooth is removed at a position located 0.2 mm from the tip of each tooth, the length X of the front end surface 77 is 0.15 mm; that the tip of each tooth is removed at a position located 0.3 mm from the tip of each tooth, the length X of the front end surface 77 is 0.22 mm; that the tip of each tooth is removed at a position located 0.35 mm from the tip of each tooth, the length X of the front end surface 77 is 0.25 mm; and that the tip of each tooth is removed at a position located 0.4 mm from the tip of each tooth, the length X of the front end surface 77 is 0.29 mm. By adopting these spurs sequentially, the length X of the front end surface 77 of the driven spur 71 is changed. Further, results shown in TABLE 1 were obtained under the following conditions: each spur 72 has 30 teeth; the quality of material of each spur 72 is SUS304-CSP (stainless steel for spring); the roller body 62 of the driving roller 61 has the diameter of 13.4 mm; the material of the roller body 62 of the driving roller 61 is ethylene-propylene-diene rubber (EPDM); the nipping force between the driving roller 61 and the driven spur 71 is 1N; and evaluation environments are that the temperature is 21 degrees Celsius and the humidity is 37%.
As shown in TABLE 1, in a case that the length X of the front end surface (hereinafter simply referred to as “length X”) is 0 mm and the angle Y is 1 degrees, that the length X is 0.04 mm and the angle Y is 3 degrees, that the length X is 0.07 mm and the angle Y is 7 degrees, and that the length X is 0.15 mm and the angle Y is 8 degrees, no jam occurs in each of the cases and the result in each of the cases is evaluated as “Jam OK” (hereinafter referred to as “No jam” and shown as “No jam” in TABLE 1). That is, “No jam” indicates that the jam of the paper P did not occur. Noted that, in a case that the length X is 0.04 mm and the angle Y is an angle of not more than 3 degrees, that the length X is 0.07 mm and the angle Y is an angle of not more than 7 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not more than 8 degrees, each of the results is presumed as “No jam”. Here, in a case that the length X is 0.07 mm and the angle Y is 6 degrees, that the length X is 0.15 mm and the angle Y is 5 degrees, and that the length X is 0.15 mm and the angle Y is 6 degrees, only the result for evaluation of the dirt is shown in each of the cases. Since the evaluation of the dirt can be performed in a case of “No jam”, in the case that the length X is 0.07 mm and the angle Y is 6 degrees, that the length X is 0.15 mm and the angle Y is 5 degrees, and that the length X is 0.15 mm and the angle Y is 6 degrees, each of the cases is also evaluated as “No jam”. Meanwhile, in a case that the length X is 0 mm and the angle Y is 2 degrees, that the length X is 0.04 mm and the angle Y is 4 degrees, that the length X is 0.07 mm and the angle Y is 8 degrees, and that the length X is 0.15 mm and the angle Y is 9 degrees, the jam occurred in each of the cases and the result in each of the cases is evaluated as “Jam NG” (hereinafter referred to as “Jam occurred” and shown as “Jam occurred” in TABLE 1). That is, “Jam occurred” indicates that the jam of the paper P occurred. Noted that, in a case that the length X is 0 mm and the angle Y is an angle of not less than 2 degrees, that the length X is 0.04 mm and the angle Y is an angle of not less than 4 degrees, that the length X is 0.07 mm and the angle Y is an angle of not less than 8 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not less than 9 degrees, each of the results is presumed as “Jam occurred”. The straight line K1 shown in
Further, as shown in TABLE 1, in a case that the length X is 0.07 mm and the angle Y is 6 degrees, that the length X is 0.15 mm and the angle Y is 5 degrees, that the length X is 0.22 mm and the angle Y is 4 degrees, that the length X is 0.25 mm and the angle Y is 3 degrees, and that that the length X is 0.29 mm and the angle Y is 3 degrees, the first paper is not dirty in each of the cases and the result in each of the cases is evaluated as “Dirt OK” (hereinafter referred to as “No dirt” and shown as “No dirt” in TABLE 1). Noted that in the case that the length X is 0 mm and the angle Y is 1 degrees and that the length X is 0.04 mm and the angle Y is 3 degrees, each of the cases is evaluated as “No dirt”. In the case that the length X is 0 mm and the angle Y is 2 degrees and that the length X is 0.04 mm and the angle Y is 4 degrees, the jam occurred in each of the cases and the evaluation of the dirt can not be performed in each of the cases. In a case that the length X is 0.07 mm and the angle Y is an angle of not more than 6 degrees, that the length X is 0.15 mm and the angle Y is an angle of not more than 5 degrees, that the length X is 0.22 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.25 mm and the angle Y is an angle of not more than 3 degrees, and that that the length X is 0.29 mm and the angle Y is an angle of not more than 3 degrees, each of the results is presumed as “No dirt”. An evaluation method of the dirt is as follows. That is, in a case that a human being having 20/20 vision looks at a discharged paper in a state that the discharge paper is kept away from the human being by 70 cm in a bright room with illuminance 534 lux and that the dirt such as an ink mark transferred to the paper P from each tooth 72a is invisible, it is evaluated as “No dirt”. On the other hand, in a case that the dirt is visible, it is evaluated as “Dirt NG” (hereinafter referred to as “Some dirt” and shown as “Some dirt” in TABLE 1). In other words, “No dirt” means that there is no dirt on the paper P and “Some dirt” means that there is the dirt on the paper P. Meanwhile, in a case that the length X is 0.07 mm and the angle Y is 7 degrees, that the length X is 0.15 mm and the angle Y is 6 degrees, that the length X is 0.22 mm and the angle Y is 5 degrees, that the length X is 0.25 mm and the angle Y is 4 degrees, and that the length X is 0.29 mm and the angle Y is 4 degrees, there is the dirt on the first paper in each of the cases and each of the results is evaluated as “Some dirt”. Noted that in a case that the length X is 0.07 mm and the angle Y is an angle of not less than 7 degrees, that the length X is 0.15 mm and the angle Y is an angle of not less than 6 degrees, that the length X is 0.22 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.25 mm and the angle Y is an angle of not less than 4 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not less than 4 degrees, each of the results is presumed as “Some dirt”. The straight line K2 shown in
The area U1K surrounded by the mathematical expressions 1 to 4 is an area in which the occurrence of jam and dirt is suppressed at the time of transporting the first paper. Therefore, by setting the length X of the front end surface 77 of the driven spur 71 and the angle Y of the driven spur 71 within this area, it is possible to suppress the occurrence of both the jam and the dirt.
Next, the area U2K will be explained. The area U2K is an area which is surrounded by X-axis, Y-axis, and two straight lines K3, K4 shown in
The mathematical expression 5 is “0.5>X>0”, the mathematical expression 6 is “Y=40.1X+2.6”, and the mathematical expression 7 is “Y=−6.0X+7.1”.
TABLE 2 given below shows presence or absence of occurrence of jam and dirt in a second paper (Business 4200 Paper, 92 bright, 28 lb. bond, 8.5×11, produced by Xerox Corporation. (USA)) in a case that an image having a predetermined pattern is recorded on the second paper and the second paper is refed to the positioning mechanism 50, under various conditions of the length X of the front end surface 77 of each tooth 72a of the driven spur 71 and the angle Y of the driven spur 71. TABLE 2 shows results which have been obtained under the same conditions as those of TABLE 1, the conditions including the length X of the front end surface 77, the number of teeth of each spur 72, the quality of material of each spur 72, the diameter of the roller body 62 of the driving roller 61, the quality of material of the roller body 62 of the driving roller 61, the nipping force between the driving roller 61 and the driven spur 71, and the evaluation environments.
As shown in TABLE 2, in a case that the length X of the front end surface (hereinafter simply referred to as “length X”) is 0 mm and the angle Y is 2 degrees, that the length X is 0.04 mm and the angle Y is 4 degrees, that the length X is 0.07 mm and the angle Y is 7 degrees, and that the length X is 0.15 mm and the angle Y is 8 degrees, no jam occurs in each of the cases and each of the results is evaluated as “No jam”. Noted that, in a case that the length X is 0 mm and the angle Y is an angle of not more than 2 degrees, that the length X is 0.04 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.07 mm and the angle Y is an angle of not more than 7 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not more than 8 degrees, each of the results is presumed as “No jam”. Meanwhile, in a case that the length X is 0 mm and the angle Y is 3 degrees, that the length X is 0.04 mm and the angle Y is 5 degrees, that the length X is 0.07 mm and the angle Y is 8 degrees, and that the length X is 0.15 mm and the angle Y is 9 degrees, the jam occurred in each of the cases and each of the results is evaluated as “Jam occurred”. Noted that, in a case that the length X is 0 mm and the angle Y is an angle of not less than 3 degrees, that the length X is 0.04 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.07 mm and the angle Y is an angle of not less than 8 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not less than 9 degrees, each of the results is presumed as “Jam occurred”. The straight line K3 shown in
As shown in TABLE 2, in a case that the length X is 0.15 mm and the angle Y is 6 degrees, that the length X is 0.22 mm and the angle Y is 6 degrees, that the length X is 0.25 mm and the angle Y is 6 degrees, and that the length X is 0.29 mm and the angle Y is 5 degrees, the second paper is not dirty in each of the cases and each of the cases is evaluated as “No dirt”. An evaluation method of the dirt for TABLE 2 is the same method as TABLE 1. Noted that in the case that the length X is 0 mm and the angle Y is 2 degrees and that the length X is 0.04 mm and the angle Y is 4 degrees, each of the cases is evaluated as “No dirt”. In the case that the length X is 0 mm and the angle Y is 3 degrees and that the length X is 0.04 mm and the angle Y is 5 degrees, the jam occurred in each of the cases and the evaluation of the dirt can not be performed in each of the cases. In a case that the length X is 0.15 mm and the angle Y is an angle of not more than 6 degrees, that the length X is 0.22 mm and the angle Y is an angle of not more than 6 degrees, that the length X is 0.25 mm and the angle Y is an angle of not more than 6 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not more than 5 degrees, each of the results is presumed as “No dirt”. Meanwhile, in a case that the length X is 0.15 mm and the angle Y is 7 degrees, that the length X is 0.22 mm and the angle Y is 7 degrees, that the length X is 0.25 mm and the angle Y is 7 degrees, and that the length X is 0.29 mm and the angle Y is 6 degrees, there is the dirt on the second paper in each of the cases and each of the results is evaluated as “Some dirt”. Noted that in a case that the length X is 0.15 mm and the angle Y is an angle of not less than 7 degrees, that the length X is 0.22 mm and the angle Y is an angle of not less than 7 degrees, that the length X is 0.25 mm and the angle Y is an angle of not less than 7 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not less than 6 degrees, each of the results is presumed as “Some dirt”. The straight line K4 shown in
The area U2K surrounded by the mathematical expressions 2, and 5 to 7 is an area in which the occurrence of jam and dirt is suppressed at the time of transporting the second paper. Therefore, by setting the length X of the front end surface 77 of the driven spur 71 and the angle Y of the driven spur 71 within this area, it is possible to suppress the occurrence of both the jam and the dirt.
Next, the area U3K will be explained. The area U3K is an area which is surrounded by X-axis, Y-axis, and two straight lines K5, K6 shown in
The mathematical expression 8 is “Y=40.1X+1.6”, and the mathematical expression 9 is “Y=−12.1X+6.0”.
TABLE 3 given below shows presence or absence of occurrence of jam and dirt in a third paper (Business 4200 Paper, 92 bright, 20 lb. bond, 8.5×11, produced by Xerox Corporation. (USA)) in a case that an image having a predetermined pattern is recorded on the third paper and the third paper is refed to the positioning mechanism 50, under various conditions of the length X of the front end surface 77 of each tooth 72a of the driven spur 71 and the angle Y of the driven spur 71. TABLE 3 shows results which have been obtained under the same conditions as those of TABLE 1, the conditions including the length X of the front end surface 77, the number of teeth of each spur 72, the quality of material of each spur 72, the diameter of the roller body 62 of the driving roller 61, the quality of material of the roller body 62 of the driving roller 61, the nipping force between the driving roller 61 and the driven spur 71, and the evaluation environments.
As shown in TABLE 3, in a case that the length X of the front end surface (hereinafter simply referred to as “length X”) is 0 mm and the angle Y is 1 degrees, that the length X is 0.04 mm and the angle Y is 3 degrees, that the length X is 0.07 mm and the angle Y is 6 degrees, and that the length X is 0.15 mm and the angle Y is 7 degrees, no jam occurs in each of the cases and each of the results is evaluated as “No jam”. Noted that, in a case that the length X is 0.04 mm and the angle Y is an angle of not more than 3 degrees, that the length X is 0.07 mm and the angle Y is an angle of not more than 6 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not more than 7 degrees, each of the results is presumed as “No jam”. Meanwhile, in a case that the length X is 0 mm and the angle Y is 2 degrees, that the length X is 0.04 mm and the angle Y is 4 degrees, that the length X is 0.07 mm and the angle Y is 7 degrees, and that the length X is 0.15 mm and the angle Y is 8 degrees, the jam occurred in each of the cases and each of the results is evaluated as “Jam occurred”. Noted that in a case that the length X is 0 mm and the angle Y is an angle of not less than 2 degrees, that the length X is 0.04 mm and the angle Y is an angle of not less than 4 degrees, that the length X is 0.07 mm and the angle Y is an angle of not less than 7 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not less than 8 degrees, each of the results is presumed as “Jam occurred”. The straight line K5 shown in
As shown in TABLE 3, in a case that the length X is 0.07 mm and the angle Y is 5 degrees, that the length X is 0.15 mm and the angle Y is 4 degrees, that the length X is 0.22 mm and the angle Y is 4 degrees, that the length X is 0.25 mm and the angle Y is 3 degrees, and that the length X is 0.29 mm and the angle Y is 2 degrees, the third paper is not dirty in each of the cases and each of the cases is evaluated as “No dirt”. Noted that in the case that the length X is 0 mm and the angle Y is 1 degrees and that the length X is 0.04 mm and the angle Y is 3 degrees, each of the cases is evaluated as “No dirt”. In the case that the length X is 0 mm and the angle Y is 2 degrees and that the length X is 0.04 mm and the angle Y is 4 degrees, the jam occurred in each of the cases and the evaluation of the dirt can not be performed in each of the cases. In a case that the length X is 0.07 mm and the angle Y is an angle of not more than 5 degrees, that the length X is 0.15 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.22 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.25 mm and the angle Y is an angle of not more than 3 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not more than 2 degrees, each of the results is presumed as “No dirt”. An evaluation method of the dirt for TABLE 3 is the same method as TABLE 1. On the other hand, in a case that the length X is 0.07 mm and the angle Y is 6 degrees, that the length X is 0.15 mm and the angle Y is 5 degrees, that the length X is 0.22 mm and the angle Y is 5 degrees, that the length X is 0.25 mm and the angle Y is 4 degrees, and that the length X is 0.29 mm and the angle Y is 3 degrees, there is the dirt on the third paper in each of the cases and each of the results is presumed as “Some dirt”. In a case that the length X is 0.07 mm and the angle Y is an angle of not less than 6 degrees, that the length X is 0.15 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.22 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.25 mm and the angle Y is an angle of not less than 4 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not less than 3 degrees, each of the results is presumed as “Some dirt”. The straight line K6 shown in
The area U3K surrounded by the mathematical expressions 1, 2 and the mathematical expressions 8, 9 is an area in which the occurrence of jam and dirt is suppressed at the time of transporting the third paper. Therefore, by setting the length X of the front end surface 77 of the driven spur 71 and the angle Y of the driven spur 71 within this area, it is possible to suppress the occurrence of both the jam and the dirt.
Next, the area U4K will be explained. The area U4K is an area which is surrounded by X-axis, Y-axis, and two straight lines K7, K8 shown in
The mathematical expression 10 is “Y=34.7X+2.2”, and the mathematical expression 11 is “Y=−9.0X+5.6”.
TABLE 4 given below shows presence or absence of occurrence of jam and dirt in a fourth paper (Business, Laser, copier and inkjet, A4, 80 g/m2, produced by Xerox Corporation. (USA)) in a case that an image having a predetermined pattern is recorded on the fourth paper and the fourth paper is refed to the positioning mechanism 50, under various conditions of the length X of the front end surface 77 of each tooth 72a of the driven spur 71 and the angle Y of the driven spur 71. TABLE 4 shows results which have been obtained under the same conditions as those of TABLE 1, the conditions including the length X of the front end surface 77, the number of teeth of each spur 72, the quality of material of each spur 72, the diameter of the roller body 62 of the driving roller 61, the quality of material of the roller body 62 of the driving roller 61, the nipping force between the driving roller 61 and the driven spur 71, and the evaluation environments.
As shown in TABLE 4, in a case that the length X of the front end surface (hereinafter simply referred to as “length X”) is 0 mm and the angle Y is 2 degrees, that the length X is 0.04 mm and the angle Y is 3 degrees, that the length X is 0.07 mm and the angle Y is 6 degrees, and that the length X is 0.15 mm and the angle Y is 7 degrees, no jam occurs in each of the cases and each of the results is evaluated as “No jam”. Noted that, in a case that the length X is 0 mm and the angle Y is an angle of not more than 2 degrees, that the length X is 0.04 mm and the angle Y is an angle of not more than 3 degrees, that the length X is 0.07 mm and the angle Y is an angle of not more than 6 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not more than 7 degrees, each of the results is presumed as “No jam”. Meanwhile, in a case that the length X is 0 mm and the angle Y is 3 degrees, that the length X is 0.04 mm and the angle Y is 4 degrees, that the length X is 0.07 mm and the angle Y is 7 degrees, and that the length X is 0.15 mm and the angle Y is 8 degrees, the jam occurred in each of the cases and each of the results is evaluated as “Jam occurred”. Noted that, in a case that the length X is 0 mm and the angle Y is an angle of not less than 3 degrees, that the length X is 0.04 mm and the angle Y is an angle of not less than 4 degrees, that the length X is 0.07 mm and the angle Y is an angle of not less than 7 degrees, and that the length X is 0.15 mm and the angle Y is an angle of not less than 8 degrees, each of the results is presumed as “Jam occurred”. The straight line K7 shown in
As shown in TABLE 4, in a case that the length X is 0.07 mm and the angle Y is 5 degrees, that the length X is 0.15 mm and the angle Y is 4 degrees, that the length X is 0.22 mm and the angle Y is 4 degrees, that the length X is 0.25 mm and the angle Y is 3 degrees, and that the length X is 0.29 mm and the angle Y is 3 degrees, the fourth paper is not dirty in each of the cases and each of the cases is evaluated as “No dirt”. Noted that in the case that the length X is 0 mm and the angle Y is 2 degrees and that the length X is 0.04 mm and the angle Y is 3 degrees, each of the cases is evaluated as “No dirt”. In the case that the length X is 0 mm and the angle Y is 3 degrees and that the length X is 0.04 mm and the angle Y is 4 degrees, the jam occurred in each of the cases and the evaluation of the dirt can not be performed in each of the cases. In a case that the length X is 0.07 mm and the angle Y is an angle of not more than 5 degrees, that the length X is 0.15 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.22 mm and the angle Y is an angle of not more than 4 degrees, that the length X is 0.25 mm and the angle Y is an angle of not more than 3 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not more than 3 degrees, each of the results is presumed as “No dirt”. An evaluation method of the dirt for TABLE 4 is the same method as TABLE 1. Meanwhile, in a case that the length X is 0.07 mm and the angle Y is 6 degrees, that the length X is 0.15 mm and the angle Y is 5 degrees, that the length X is 0.22 mm and the angle Y is 5 degrees, that the length X is 0.25 mm and the angle Y is 4 degrees, and that the length X is 0.29 mm and the angle Y is 4 degrees, there is the dirt on the fourth paper in each of the cases and each of the results is evaluated as “Some dirt”. Noted that, in a case that the length X is 0.07 mm and the angle Y is an angle of not less than 6 degrees, that the length X is 0.15 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.22 mm and the angle Y is an angle of not less than 5 degrees, that the length X is 0.25 mm and the angle Y is an angle of not less than 4 degrees, and that the length X is 0.29 mm and the angle Y is an angle of not less than 4 degrees, each of the results is presumed as “Some dirt”. The straight line K8 shown in
The area U4K surrounded by the mathematical expressions 2, 5 and the mathematical expressions 10, 11 is an area in which the occurrence of jam and dirt is suppressed at the time of transporting the fourth paper. Therefore, by setting the length X of the front end surface 77 of the driven spur 71 and the angle Y of the driven spur 71 within this area, it is possible to suppress the occurrence of both the jam and the dirt.
Next, the area U5K will be explained. The area (first area) U5K is an area which is surrounded by X-axis, Y-axis, and four straight lines K2, K5, K6, K8 shown in
Further, as shown in
Those shown in
The mathematical expression 12 is “Y=46.7X+1.0”, and the mathematical expression 13 is “Y=−16.7X+7.2”.
In
The area U2Q is an area which is surrounded by X-axis, Y-axis, and two straight lines Q3, Q4 shown in
The mathematical expression 14 is “Y=40.0X+2.0”, and the mathematical expression 15 is “Y=−7.1X+7.1”.
In
The area U3Q is an area which is surrounded by X-axis, Y-axis, and two straight lines Q5, Q6 shown in
The mathematical expression 16 is “Y=40.0X+1.0”, and the mathematical expression 17 is “Y=−13.6X+6.0”.
In
The area U4Q is an area which is surrounded by X-axis, Y-axis, and two straight lines Q7, Q8 shown in
The mathematical expression 18 is “Y=36.4X+1.5”, and the mathematical expression 19 is “Y=−10.0X+5.5”.
In
The area U5Q (second area) is an area which is surrounded by X-axis, Y-axis, and four straight lines Q2, Q5, Q6, Q8 shown in
Next, an explanation will be made below about the positioning operation for the paper P performed by the positioning mechanism 50 while referring to
At first, the paper P is transported to the positioning mechanism 50 by the transport roller pair 47. In a case that the forward end of the paper P arrives at the driving roller 61 and the driven spur 71 as shown in
The paper P is continued to be transported in the direction J so as to be drawn to the guide surface 54a after the contact with the guide surface 54a. In this situation, the contact of the paper P with the guide surface 54a causes a reactive force in a direction T (direction away from the guide surface 54a) which acts on a portion, of the paper P, making contact with the tooth 72a of the spur 72. The reactive force in the direction T increases, as the amount of sticking of the tooth 72a of the spur 72 with respect to the paper P increases, under the condition that the angle Y of the driven spur 71 is the same. The tooth 72a of the spur 72 in this embodiment has the front end surface 77, and thus the tooth 72a is less likely to stick in the paper P. As shown in
In a case that the angle Y of the driven spur 71 is within the area U5K, an upper limit thereof is regulated. On the other hand, in a case that the angle Y exceeds the area U5K, the distance, in the main scanning direction, which causes the tooth 72a to approach the guide surface 54a while the tooth 72a is brought in contact with the paper P, is long. Then, even when the tooth 72a has the front end surface 77, the distance of the relative movement of when the paper P is moved in the direction T relative to the tooth 72a is long. As a result, the ink rubbed on the paper P from the tooth 72a is increased, which makes the paper P dirty. Further, in the case that the angle Y exceeds the area U5K, the movement amount of the paper P to approach the guide surface 54a is too large and thereby the paper P is bent between the driven spur 71 and the guide surface 54a in some cases. Furthermore, the reactive force in the direction T also increases. Then, a rotational load of the driven spur 71 increases, which causes a feed error of the paper. The jam of the paper P is caused by at least any of the above undesired matters. In this embodiment, however, by setting the angle Y of the drive spur 71 within the area U5K (area U6), even when the paper P is moved in the direction T relative to the tooth 72a, the distance of relative movement is short and the dirt on the paper P can be suppressed. In addition to this, the movement amount of the paper P to approach the guide surface 54a is also reduced, and thereby the paper P is less likely to be bent between the driven spur 71 and the guide surface 54a. Further, the reactive force in the direction T is also reduced, the rotational load of the driven spur 71 is reduced. Accordingly, the occurrence of jam can be suppressed.
The driven spur 71 makes contact with the paper P as follows. That is, the front end surface 77 of each tooth 72a sequentially makes contact with the paper P while the driven spur 71 is rotated in association with the transport of the paper P. A contact area of the driven spur 71 with the paper P corresponds to the front end surface 77 of each tooth 72a, and thus the contact area of the driven spur 71 with the paper P is considerably smaller than that of a feeding runner having an outer circumferential surface in a columnar shape. Therefore, even when the ink is adhered to the front end surface 77 owing to the contact between the front end surface 77 and the image, since the front end surface 77 itself is small, the amount of the ink transferred to the paper P is also small. In other words, the ink transferred to the paper P is more likely to be reduced, as the contact area with the paper P is smaller. As a result, the ink is less likely to be transferred to the paper P from the driven spur 71 and the dirt on the paper P can be suppressed.
Further, since the tooth 72a is less likely to stick in the paper P, force for restricting the relative movement of the paper P in the direction T relative to the tooth 72a is also reduced. Thus, even when the reactive force in the direction T acts on the paper P, since the paper P is moved in the direction T relative to the tooth 72a, the reactive force in the direction T exerted on the paper P can be allowed to escape. If the reactive force in the direction T can not be allowed to escape, the reactive force becomes a heavy rotational load on the driven spur and the feed error of the paper P may arise in some cases. Further, in the case that the reactive force in the direction T can not be allowed to escape, the paper P is held such that the paper P can not be moved in the direction T relative to each tooth of the driven spur. Then, the paper P is continuously transported toward the guide surface 54a, so that the paper P is bent between the driven spur 71 and the guide surface 54a in some cases. The jam of the paper P is caused by at least any of the above undesired matters. In this embodiment, however, the front end surface 77 is formed in each tooth 72 of each spur 72, and thus the force in the direction T can be allowed to escape as compared with the case of each tooth having the sharp tooth tip. Therefore, the jam of the paper P can be suppressed.
As described above, in a case that the paper P is transported, the paper P is transported by the driving roller 61 and the driven spur 71 to be drawn to the side of the guide surface 54a, even when the paper P is brought in contact with the guide surface 54a. Since the length X of the front end surface 77 and the angle Y of the driven spur 71 are within the area U5K (area U5Q or area U6), the paper P can be transported in the transport direction E while suppressing the occurrence of the jam and the dirt. Accordingly, it is performed the positioning of the paper P in the main scanning direction.
According to the printer 1 of this embodiment, the driven spur 71 includes the spurs 72, each of which has the teeth 72a having the front end surfaces 77 respectively. When the driven spur 71 is inclined so that the paper P is drawn to the guide surface 54a, the length X of the front end surface 77 and the angle Y of the driven spur 71 are configured to be within the area U5K. Accordingly, for example, in a case that any of the different types of first to fourth paper is transported as the paper P, it is possible to suppress the occurrence of both the jam of the paper P and the dirt on the paper P.
The preferred embodiment of the present teaching has been explained above. However, the present teaching is not limited to the embodiment described above, for which various changes can be made within a range of definition of claims. For example, in the above embodiment, the length X of the front end surface 77 of the tooth 72a of the driven spur 71 and the angle Y of the driven spur 71 are within the area U6. However, they may be within the area U5K or U5Q other than the area U6. The front end surface 77 in the above embodiment may be formed by etching, machine processing, or the like. The etching may be double-sided etching or single-sided etching including single-sided half etching. In a case that the front end surface 77 is formed by the etching, the front end surface 77 may have a curved surface which is concave toward the side of the axis L1. Further, the front end surface 77 may have a convex shape which is convex in a direction away from the axis L1.
In the above embodiment, the driven spur 71 includes the four spurs 72. However, the number of spurs 72 may be 1, 2, 3, or 5 or more. The positioning mechanism 50 may be provided in the downstream guide section 3b. Accordingly, the paper P is discharged to the paper discharge section 4 in a state of being positioned.
The present teaching is applicable to any of the line type and the serial type. Further, the present teaching is also applicable to the facsimile, the copying machine, or the like, without being limited to the printer. Further, the present teaching is applicable to any recording apparatus including, for example, those of the laser type and the thermal type provided that the recording apparatus records the image. The recording medium is not limited to the paper P, and the recording medium may be various media capable of performing the recording thereon.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-040077 | Feb 2013 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5850233 | Otsuka et al. | Dec 1998 | A |
| 5912690 | Endo et al. | Jun 1999 | A |
| 20140240428 | Norikane | Aug 2014 | A1 |
| 20140240429 | Norikane et al. | Aug 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| H03293136 | Dec 1991 | JP |
| H10129911 | May 1998 | JP |
| H11130299 | May 1999 | JP |
| 2007-161361 | Jun 2007 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20140240429 A1 | Aug 2014 | US |
